didanosine and Viremia

To monitor the anti-HIV-1 activity of antiretroviral agents in patients with HIV-1 infection.. Quantification of viral RNA copy in plasma or serum using a polymerase chain reaction method coupled with reverse transcription.. The HIV-1 RNA copy number represents the HIV-1 viremia status in patients with HIV-1 infection. This copy number is likely to be useful in monitoring the effectiveness of antiviral therapy and the method is likely to be built into every clinical trial of anti-HIV-1 therapy in the near future.

Topics: Antiviral Agents; Didanosine; Drug Resistance, Microbial; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Polymerase Chain Reaction; Reproducibility of Results; RNA, Viral; Sensitivity and Specificity; Transcription, Genetic; Viremia; Virus Replication

Numerous national antiretroviral (ARV) treatment initiatives offering protease inhibitor-sparing combination antiretroviral therapy (cART) have recently commenced in southern Africa, the first of which began in Botswana in January 2002. Evaluation of the efficacy and tolerability of various protease inhibitor-sparing cART regimens requires intensive study in the region, as does investigation of the development of drug resistance and the optimal means of sustaining adherence. The "Tshepo" Study is the first large-scale, randomized, clinical trial that addresses these important issues among HIV-1 subtype C-infected ARV treatment-naive adults in southern Africa.. The Tshepo Study is a completed, open-labeled, randomized study that enrolled 650 ARV-naive adults between December 2002 and 2004. The study is a 3 x 2 x 2 factorial design comparing the efficacy and tolerability among factors: (1) 3 combinations of nucleoside reverse transcriptase inhibitors (NRTIs): zidovudine (ZDV) + lamivudine (3TC), ZDV + didanosine (ddI), and stavudine (d4T) + 3TC; (2) 2 different nonnucleoside reverse transcriptase inhibitors (NNRTIs): nevirapine and efavirenz; and (3) 2 different adherence strategies: the current national "standard of care" versus an "intensified adherence strategy" incorporating a "community-based directly observed therapy." Study patients were stratified into 2 balanced CD4 T-cell count groups: less than 201 versus 201-350 cells per cubic millimeter with viral load greater than 55,000 copies per milliliter. Following Data Safety Monitoring Board recommendations in April 2006, ZDV/ddI-containing arms were discontinued due to inferiority in primary end point, namely, virologic failure with resistance. We report both overall data and pooled data from patients receiving ZDV/ddI- versus ZDV/3TC- and d4T/3TC-containing cART through April 1, 2006.. Four hundred fifty-one females (69.4%) and 199 males with a median age of 33.3 years were enrolled into the study. The median follow-up as of April 1, 2006, was 104 weeks, and loss to follow-up rate at 2 years was 4.1%. The median baseline CD4 T-cell count was 199 cells per cubic millimeter [interquartile ratio (IQR) 136-252], and the median plasma HIV-1 RNA level was 193,500 copies per milliliter (IQR 69-250, 472-500). The proportion of participants with virologic failure and genotypic resistance mutations was 11% in those receiving ZDV/ddI-based cART versus 2% in those receiving either ZDV/3TC- or d4T/3TC-based cART (P = 0.002). The median CD4 T-cell count increase at 1 year was 137 cells per cubic millimeter (IQR 74-223) and 199 cells per cubic millimeter (IQR 112-322) at 2 years with significantly lower gain in the ZDV/ddI arm. At 1 and 2 years, respectively, 92.0% and 88.8% of patients had an undetectable plasma HIV-1 RNA level (< or = 400 copies/mL). Kaplan-Meier survival estimates at 1 and 2 years were 96.6% and 95.4%. One hundred twenty patients (18.2%) had treatment-modifying toxicities, of which the most common were lipodystrophy, anemia, neutropenia, and Stevens-Johnson syndrome. There was a trend toward difference in time to treatment-modifying toxicity by pooled dual-NRTI combination and no difference in death rates.. The preliminary study results show overall excellent efficacy and tolerability of NNRTI-based cART among HIV-1 subtype C-infected adults. ZDV/ddI-containing cART, however, is inferior to the dual NRTIs d4T/3TC or ZDV/3TC when used with an NNRTI for first-line cART.

Topics: Adult; AIDS-Related Opportunistic Infections; Anti-HIV Agents; Botswana; CD4 Lymphocyte Count; Didanosine; Drug Tolerance; Female; HIV Infections; HIV-1; Humans; Male; Patient Compliance; RNA, Viral; Survival Analysis; Time Factors; Viremia; Zidovudine

To describe the occurrence of a high early virological failure (VF) rate and development of resistance mutations in antiretroviral-naive patients receiving tenofovir, didanosine and efavirenz.. HIV-infected antiretroviral-naive patients with viral load > or =30 000 copies/ml were enrolled in a pilot randomized trial of tenofovir/didanosine (250 mg)/ efavirenz with (arm A) or without (arm B) lopinavir/r for the first 12 weeks. As six cases of early VF (a drop of <2 log at month 3, or a rebound of >1 log from the nadir) were detected (five in arm B and one in arm A who had previously stopped lopinavir/r) an unplanned interim analysis was performed.. A total of 29 out of 36 enrolled patients completed at least 3 months of follow-up and were included in the interim analysis. An intent-to-treat analysis showed treatment failure in 7/15 (46.7%) patients in arm B (five VF, one lost, one switched) versus 2/14 (14.3%) in arm A (one lost, one switched) (P=0.109). The patient in arm A who interrupted lopinavir/r at day 3 and continued with tenofovir/didanosine/efavirenz later developed VF. At baseline, 6/6 VF patients had VL >100000 copies/ml and an advanced stage of disease (CD4 <200 plus CDC stage C or B3) versus 0/8 non-VF patients taking the triple drug regimen (P<0.001). At failure, G190S/E alone or associated with K103N and K101R mutations was detected in five patients, and K103N/L1001/V108l in the sixth patient. Additionally, L74V/I and K65R were detected in four and two patients, respectively.. A high early virological failure rate and the occurrence of resistance mutations were detected in a group of antiretroviral-naive patients treated with tenofovir/didanosine/efavirenz.

Topics: Adenine; Adult; Aged; Alkynes; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Benzoxazines; Cyclopropanes; Didanosine; Drug Resistance, Viral; Female; HIV Infections; HIV-1; Humans; Lopinavir; Male; Middle Aged; Mutation; Organophosphonates; Oxazines; Pyrimidinones; RNA, Viral; Tenofovir; Time Factors; Treatment Failure; Viremia

The goal of this study was to optimize the hydroxyurea dosage in HIV-infected patients, and to minimize the toxicity and maximize the antiviral efficacy of the hydroxyurea-didanosine combination. In a randomized, open-label study (RIGHT 702, a multicenter trial performed in private and institutional practices), three daily doses (600 microg, 800-900 microg, and 1200 microg) of hydroxyurea were administered in combination with didanosine and stavudine to 115 chronically HIV-infected patients, one-third antiretroviral drug naive, with viremia between 5000 and 200,000 copies/ml regardless of CD4+ cell count. The primary efficacy end point was the proportion of patients with plasma HIV-1 RNA levels below 400 copies/ml after 24 weeks of therapy. In the RIGHT 702 intent-to-treat population the lowest (600 mg) dose of hydroxyurea was better tolerated, associated with fewer adverse events, and more potent by all efficacy parameters, including the primary end point (76 versus 60% patients with viremia<400 copies/ml at week 24 for the 600-mg and 800- to 900-mg dose groups, respectively; p=0.027), the mean area under the curve (60.3 versus 65.8; p=0.016), and the mean log10 decrease (-1.95 versus -0.77; p=0.001). Patients receiving 600 mg of hydroxyurea daily also had the highest CD4+ cell count, CD4+/CD8+ cell ratio, and lowest CD8+ cell count and percentage (p=0.035). The RIGHT 702 trial provides an explanation for the increased toxicity and decreased efficacy of hydroxyurea when it was used at high dosage (1200 mg daily). At the optimal dosage of 600 mg daily, hydroxyurea, in combination with didanosine, deserves reevaluation for the long-term management of HIV/AIDS worldwide, because of its excellent resistance profile, durability, and affordability.

Topics: Anti-HIV Agents; CD4 Lymphocyte Count; CD4-CD8 Ratio; Didanosine; Drug Therapy, Combination; Drug-Related Side Effects and Adverse Reactions; Female; HIV; HIV Infections; Humans; Hydroxyurea; Male; RNA, Viral; Stavudine; Viral Load; Viremia

Despite dramatic reduction of the levels of human immunodeficiency virus type I (HIV-1) virions in blood and seminal plasma of infected patients, highly active antiretroviral therapy (HAART) does not eradicate HIV-1. Three patients, with less than 50 copies/ml of plasma viral RNA, were enrolled in this eradication protocol. Didanosine (DDI) and hydroxyurea (HU) were added to their baseline HAART and after a month of therapy, low dose OKT3, followed by a 2-week course of interleukin 2 (IL-2), was administrated. All antiretroviral therapy was then interrupted and the three patients developed viral rebound in the peripheral blood. The V3 loop region of the HIV-1 gp120 from cell-free viral RNA and proviral DNA in blood and seminal compartments was sequenced in one patient. The two major viral isolates in semen cells were macrophage- tropic (R5) and dual-tropic (R5X4), and these isolates were also present in the PBMCs. Six months after the viral rebound, we demonstrated a shift toward dual tropism in semen cell-associated HIV-1 proviral DNA, with the first appearance of a T-lymphotropic (X4) provirus solely in this compartment. The virus responsible for the blood plasma viral rebound was never found in the semen microenvironment. This study suggests viral compartmentalization of the semen microenvironment after an intensification and stimulatory HIV-1 eradication protocol, with evidence of viral evolution.

Topics: Amino Acid Sequence; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Didanosine; DNA, Viral; HIV Envelope Protein gp120; HIV Infections; HIV-1; Humans; Hydroxyurea; Immunosuppressive Agents; Interleukin-2; Male; Molecular Sequence Data; Muromonab-CD3; Nucleic Acid Synthesis Inhibitors; Peptide Fragments; Phylogeny; Proviruses; RNA, Viral; Semen; Sequence Alignment; Treatment Outcome; Viremia; Withholding Treatment

Toxicity and other drug adherence-related factors have contributed to decreased compliance to antiretroviral regimens amongst HIV-infected patients. Irregular therapy disruption causes loss of CD4 T cells, onset of drug resistance and rapid rebound of plasma viral load (VL). However, an appropriate choice of drugs and properly scheduled structured treatment interruptions (STIs) may limit VL rebound, maintain CD4 counts and minimize resistance.. We conducted a clinical study of STIs, RIGHT 901, involving 60 drug-naive patients with chronic HIV infection (CD4 >300, VL >10,000) randomized to receive didanosine-stavudine-indinavir (IDV group) or didanosine-stavudine-hydroxyurea (HU group), for 12 weeks. Subsequently, all patients were randomized again to start STI (short induction) or to continue the therapy for an additional 24 weeks before starting STI (long induction). Both groups underwent four STI cycles and then stopped therapy as long as viraemia remained below 10,000 copies/ml before reinitiating another four cycles of STI.. During continuous therapy VLs were suppressed at similar rates in both the HU and IDV groups, while a blunted CD4 count was documented in the HU group. Following the first stop median VL rebounded close to baseline values in both groups, however, during the following STI median VL rebound decreased in the HU group, while in the IDV group VL continued to rebound to values close to baseline, and the difference between the two groups was statistically significant. Moreover, patients treated with HU had a constant and stable CD4 increase during STI, whereas CD4 counts fluctuated in the IDV group, with sharp falls during treatment interruptions and partial CD4 recovery following treatment restart. Even in the presence of IDV resistance predisposing mutations at baseline, no genotypic change in the protease sequence was observed during STI. A relevant mutation in the reverse transcriptase sequence (K70R) emerged in one patient interrupting treatment after 36 weeks of continuous therapy and in one patient after four STI cycles. Side effects (no major events) were similar among groups.. An appropriate choice of STI schedule and regimens containing drugs less prone to resistance and/or able to prevent CD4 fluctuation may contribute to optimizing STI for chronically infected patients with respect to limiting viral rebound, improving CD4 counts and maintaining a resistance profile comparable to continuous highly active antiretroviral therapy.

Topics: Anti-HIV Agents; CD4-Positive T-Lymphocytes; Didanosine; Drug Administration Schedule; Drug Resistance, Viral; Drug Therapy, Combination; HIV-1; Humans; Hydroxyurea; Indinavir; Italy; RNA, Viral; Stavudine; Time Factors; Viral Load; Viremia

Twenty-four subjects presenting at a single treatment center with primary HIV infection were enrolled in a pilot study aimed to establish the possible role of hydroxyurea in this setting. Study participants were randomly assigned to receive or not to receive hydroxyurea in addition to stavudine (d4T) plus didanosine (ddI) and nevirapine (NVP). Seventy-five percent of patients without hydroxyurea had plasma HIV RNA below 50 copies/mL at 48 weeks by both intention-to-treat (ITT) and on-treatment (OT) analysis in comparison with 50% (ITT) and 67% (OT) of patients with hydroxyurea (p >.1). A median increase of >200 cells/mm3 was observed from baseline to week 48 whether or not hydroxyurea was included in the regimen. Overall, in 12 patients treated with hydroxyurea, 33 adverse events were reported versus 19 reported for 12 patients who did not receive hydroxyurea (p <.05). Our results suggest that that adding hydroxyurea to a regimen of d4T plus ddI and NVP increases toxicity without improving the antiviral effect.

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; Didanosine; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Hydroxyurea; Male; Middle Aged; Nevirapine; Pilot Projects; Reverse Transcriptase Inhibitors; RNA, Viral; Stavudine; Viremia

To assess the effects of five-drug combination therapy on HIV-1 load in lymph nodes and subsequent maintenance with four and three drugs.. Ten pharmacotherapeutically naive patients received a combination of zidovudine, lamivudine, didanosine, ritonavir, and saquinavir for 24 weeks, then zidovudine, lamivudine, didanosine, and saquinavir for the next 24 weeks, and finally zidovudine, lamivudine, and saquinavir for the last 24 weeks. HIV-1 RNA in lymph nodes was measured using quantitative polymerase chain reaction (PCR) at baseline, after 12, 24, 48, and 78 weeks. Plasma HIV-1 RNA, proviral DNA in peripheral blood mononuclear cells (PBMCs), circulating lymphocyte subsets, and protease inhibitor levels in blood were also regularly measured. Genotypic resistance was assessed in the different compartments in 2 patients who were failed by therapy.. HIV-1 RNA decreased in lymph nodes in 9 patients and was stable in 1 despite initial control of plasma replication <20 copies/ml in each patient. Lymph node levels rebounded in 1 patient at week 72 as a result of lack of adherence and remained stable in the 8 others despite maintenance regimens. This represents a mean drop of -3.17 log in lymph nodes for the 8 patients maintaining undetectable viremia at 72 weeks. In the patient with stable lymph node viral RNA, selection of the M184V mutation was demonstrated at this level before detection in plasma and low blood saquinavir levels were found throughout the study. Continuous improvements in immune parameters were observed in all cases, although PBMC proviral DNA levels either showed a continuous decrease or stabilized to a plateau.. More complex regimens do not perform better in lymph nodes than classic triple therapy. The persistence of HIV-1 RNA in lymph nodes could be related with cellular resistance mechanisms rather than an insufficient potency of the regimens.

Topics: Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Biopsy; CD4 Lymphocyte Count; Didanosine; DNA, Viral; Drug Therapy, Combination; Female; France; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Lamivudine; Lymph Nodes; Lymphocyte Subsets; Lymphocytes; Male; Polymerase Chain Reaction; Ritonavir; RNA, Viral; Saquinavir; Time Factors; Viral Load; Viremia; Virus Replication

To evaluate the decay rate of cellular proviral HIV-DNA and viral replication in patients receiving highly active antiretroviral therapy (HAART) in the very early phase of infection.. Thirty-four patients treated with HAART and retrospectively selected for progressive decline of plasma viraemia up to undetectable levels (< 20 copies/ml), were stratified according to CD4+ cell count and plasma viraemia at base line: > 500 x 10(6) cells/l with < 5000 copies/ml (group 1) or with > 5000 copies/ml (group 2), > 5000 copies/ml with 300-500 x 10(6) cells/l (group 3) or with < 300 x 10(6) cells/l (group 4). Plasma HIV-RNA and proviral HIV-DNA were analysed at baseline and after 1, 2, 3, 6, 9 and 12 months of treatment.. After 1 year of treatment, a significant decrease of proviral DNA titre was observed in all patients and a decrease > 1 log was achieved in 24 of 29 subjects of the first three groups. The more pronounced decay of HIV-DNA (half-life 28 weeks) up to < 50 HIV-DNA copies/10(6) CD4+ cells was detected in patients of group 1. At the year's endpoint, five patients (four in group 1 and one in group 2) had < 20 HIV-DNA copies. However, HIV strains sensitive to antiretroviral drugs were isolated from peripheral lymphocytes of 16 out of 34 patients.. In patients with undetectable plasma viraemia after 1 year of HAART, the highest reduction of proviral DNA up to < 50 copies/10(6) CD4+ cells was obtained only in subjects in the early asymptomatic phase of infection. Nevertheless, a replication-competent virus can be detected in all phases of antiretroviral therapy.

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; Didanosine; DNA, Viral; Drug Therapy, Combination; Female; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Indinavir; Male; Middle Aged; Prospective Studies; Proviruses; Reverse Transcriptase Inhibitors; Reverse Transcriptase Polymerase Chain Reaction; RNA, Viral; Stavudine; Viremia

Nineteen HIV-seropositive antiretroviral therapy-naive and asymptomatic individuals (200-500 CD4/microl) were enrolled in a prospective study aimed at analyzing the immunologic and virologic effects of two different combinations of nucleoside reverse transcriptase inhibitors (AZT+ddI and AZT+3TC), and randomly assigned to one of the treatment group. Immunologic (CD4 and CD8 counts, mitogen-stimulated cytokine production, unstimulated and mitogen-stimulated apoptosis) and virologic (HIV viral load) determinations were performed pre-therapy and 15, 30, 90, 200 and 360 days after initiation of therapy. Results showed that the two combinations had comparable effects on increasing CD4 counts and the CD4/CD8 ratio and in reducing HIV viral load. In contrast, AZT+3TC was more efficient in improving interleukin-2 (IL-2) and interferon gamma (IFNgamma) production as well as the type 1/type 2 cytokine ratio and in down modulating the susceptibility of peripheral blood mononuclear cells to in vitro mitogen-stimulated apoptotic cell death. These data suggest that the combination of AZT+3TC has a stronger effect on potentially beneficial immune parameters (IL-2 production; reduction of apoptosis) than the one between AZT+ddI. The combination of AZT+3TC could be more advantageous in the therapy of HIV infection even when used in association with a protease inhibitor.

Topics: Anti-HIV Agents; Apoptosis; CD4 Lymphocyte Count; CD4-CD8 Ratio; Cytokines; Didanosine; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; Lamivudine; Leukocytes, Mononuclear; Prospective Studies; Reverse Transcriptase Inhibitors; Th1 Cells; Viremia; Zidovudine

Topics: Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Daunorubicin; Didanosine; Drug Therapy, Combination; Herpesvirus 8, Human; HIV Infections; HIV Protease Inhibitors; Humans; Indinavir; Lamivudine; Reverse Transcriptase Inhibitors; Sarcoma, Kaposi; Stavudine; Viremia

Cell activation is essential for HIV infection. CD4+ T lymphocyte activation allows virus replication and CD8+ T lymphocyte activation may contribute to pathogenesis. We combined hydroxyurea, a cytostatic drug that inhibits cell activation and proliferation, with two drugs that inhibit HIV (didanosine and indinavir), to block the "cell activation-virus production-pathogenesis" cycle. HIV was strongly suppressed in treated patients, and the average CD4 count increased to 224/mm3. Compared with a matched group of patients who had declined antiretroviral treatment, treated patients had a significantly lower proportion of activated CD8+ T lymphocytes and a significantly higher number of naive CD8+ and CD4+ T lymphocytes. The proliferative responses to allogeneic and influenza virus antigens were increased in treated patients, and a defect in CD3-zeta expression, the signaling chain of the T cell receptor complex, was reversed. The use of a cytostatic drug was not detrimental to the immune system; on the contrary, the combination of antiviral and cytostatic treatment improved all of the immune parameters tested.

Topics: Anti-HIV Agents; CD3 Complex; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Didanosine; Drug Therapy, Combination; HIV Infections; HIV Protease Inhibitors; Humans; Hydroxyurea; Indinavir; Lymphocyte Activation; Nucleic Acid Synthesis Inhibitors; Reverse Transcriptase Inhibitors; Viremia

A total of 151 previously untreated patients infected with human immunodeficiency virus type 1 (HIV-1) with CD4 cell counts >/=200/microL and plasma HIV-1 RNA levels of 10,000-100,000 copies/mL were randomly assigned to 24 weeks of open-labeled stavudine plus didanosine (group 1), zidovudine plus lamivudine (group 2), or stavudine plus didanosine followed by zidovudine plus lamivudine (group 3). The mean decrease in HIV-1 RNA level was greater in group 1 (2.26 log10 copies/mL) than in groups 2 (1.26 log10 copies/mL) or 3 (1.58 log10 copies/mL; P<.0001). The mean increase in CD4 cell counts was greater in groups 1 (124 cells/microL) and 3 (118 cells/microL) than in group 2 (62 cells/microL; P=.02). All regimens were generally well tolerated. The combination of stavudine plus didanosine reduced plasma HIV-1 RNA concentrations and increased CD4 cell counts more effectively than did the combination of zidovudine plus lamivudine or the regimen alternating both combinations.

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; Didanosine; Drug Administration Schedule; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Lamivudine; Male; Reverse Transcriptase Inhibitors; RNA, Viral; Stavudine; Treatment Outcome; Viremia; Zidovudine

The progression of HIV-1 disease appears associated with an unregulated Fas-mediated apoptosis of lymphocytes that involves the activation of ICE protease and ceramide generation and antiviral therapy may not be fully effective in the absence of a relevant impact on apoptosis. Six drug-naive HIV-1-infected symptomless patients with advanced immunodeficiency were treated with combined AZT and ddl for 4 months; plasma HIV-1 RNA levels, the counts of CD4 cells, CD4 and CD8 apoptotic lymphocytes, Fas-positive cells and ICE-positive cells, and intracellular ceramide levels were measured at base-line and after 7, 45 and 120 days of treatment. There was a prompt reduction in plasma viremia and a secondary increase in CD4 counts, but the treatment had no impact on apoptotic CD4 and CD8 lymphocytes, Fas-positive cells and ICE-positive cells, and on the intracellular levels of ceramide. A discrepancy exists between the positive impact of combined AZT and ddl treatment on plasma viral load and CD4 counts and the lack of any effect on the process of lymphocyte apoptosis. We suggest to use the measurement of apoptotic lymphocytes as a surrogate marker to predict, in combination with viral load and CD4 counts, a large proportion of the clinical effect of antiviral therapy.

Topics: Adult; Anti-HIV Agents; Apoptosis; Caspase 1; CD4 Lymphocyte Count; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Ceramides; Didanosine; Drug Therapy, Combination; fas Receptor; HIV Infections; HIV-1; Humans; Male; Mitochondria; Viral Load; Viremia; Zidovudine

Most current guidelines state that antiretroviral therapy should be considered for HIV-infected patients with plasma HIV RNA > 5000-10000 copies/ml and CD4 cells > 500 x 10(6) cells/l. However, there is increasing concern about whether this is the optimal point to begin treatment or whether it is better to delay the initiation to more advanced stages.. To study the immunological and virological benefits of starting antiretroviral therapy at these early stages.. A total of 161 HIV-infected asymptomatic patients with CD4 cell count > 500 x 10(6) cells/l and viral load > 10000 copies/ml were randomly assigned to one of five treatment groups: no treatment, twice daily zidovudine and thrice daily zalcitabine (ZDV-ddC), twice daily zidovudine and didanosine (ZDV-ddI), twice daily stavudine and didanosine (D4T-ddI), or a twice daily three-drug regimen with stavudine and lamivudine and ritonavir. The endpoints were progression to < 350 x 10(6) cells/l CD4 cells, to < 500 x 10(6) cells/l with either two Centers for Disease Control class B symptoms or an increase of viral load > 0.5 log10 copies/ml above baseline, or to AIDS or death. In various substudies, the lymphoid tissue and cerebrospinal fluid viral load, development of genotypic resistance, proliferative responses to mitogens and cytomegalovirus, and HIV-1 specific antigens and other immunophenotypic markers were also analysed.. Progression rates to study endpoints within 1 year were greater in the control group (31%) than in all groups receiving antiretroviral therapy pooled together (5%; estimated hazard ratio 7.41; 95% confidence interval 5.72-74.55; P < 0.001). The peak mean viral load decrease was greater in the three-drug group when compared with any of the three groups with a two-drug regimen (2.32, 1.65, 1.72 and 1.84, respectively; P < or = 0.001). At 1 year, viral load remained below 20 copies/ml in 30 out of 33 patients in the three-drug group (91%) and in only eight out of 94 patients (9%) in two-drug groups (P = 0.001). The peak mean increase in CD4 cells was also greater in the three-drug group than in the double treatment arms (259 versus 85, 144 and 145 x 10(6) cells/l, respectively; P = 0.001). By comparison, 36% of patients in the three-drug group regimen had to change the therapy as a result of adverse events. Substudies were performed in 60 patients recruited at two sites. Tonsillar tissue HIV RNA was measured in seven patients (two in the two-drug groups and five in the three-drug group) in whom plasma HIV RNA was < 20 copies/ml at 1 year. It was 15151 and 133333 copies/mg tissue in the two patients from the two-drug group, < 40 copies/mg tissue in four patients in the three-drug group, and 485 copies/mg in one patient in the three-drug group. At 1 year there was a mean increase of 4.21+/-2.94% in CD8+CD38+ cells in the control group and a decrease of 9.48+/-3.36% in the two-drug groups (P = 0.01), and 19.87+/-3.64 in the three-drug group (P = 0.001 and P = 0.05, for comparisons with control group and two-drug groups, respectively). Although proliferative responses to cytomegalovirus antigens were significantly greater in those receiving antiretroviral therapy, response to HIV-1 p24 antigen was not detected in any patient in either treatment group.. This study supports the recommendation to start antiretroviral therapy with a three-drug combination during very early stages of HIV-1 disease, at least if viral load is above a cut-off point (10000 copies/ml in our study). The risk of progression was sevenfold higher in non-treated patients at 8 months of follow-up. Some immune system parameters improved toward normal values after 1 year of antiretroviral therapy, but the proliferative response of CD4 T lymphocytes against the p24 HIV-1 antigen was not recovered. Therapeutic approaches with more potent, better-tolerated and more convenient regimens will increasingly favour early intervention with antiretroviral t

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; CD4-CD8 Ratio; Didanosine; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Lamivudine; Male; Palatine Tonsil; Ritonavir; RNA, Viral; Spain; Stavudine; Viremia; Zalcitabine; Zidovudine

Topics: Anti-HIV Agents; CD4 Lymphocyte Count; Didanosine; Drug Therapy, Combination; Female; HIV; HIV Infections; Humans; Interleukin-2; Leukocyte Common Antigens; Male; Pilot Projects; RNA, Viral; Viremia; Zidovudine

To explore the short-term effects on surrogate markers for HIV progression of didanosine (ddl) plus stavudine (d4T), with or without hydroxyurea.. Randomized, double-blinded, prospective study.. Swiss HIV Cohort Study.. A total of 144 patients (75% antiretroviral-naive) were studied (mean baseline HIV-1 RNA, 4.53 log10 copies/ml; mean CD4 cell count, 370 x 10(6)/l).. Patients received ddl (200 mg twice daily) plus d4T (40 mg twice daily), with additional hydroxyurea (500 mg twice daily) or placebo.. The primary endpoint was a reduction of viraemia below 200 copies/ml after 12 weeks. At that time, patients who did not reach the primary endpoint were withdrawn in the hydroxyurea arm, whereas patients in the placebo group had the option of adding hydroxyurea to ddl and d4T. All patients were followed until week 24.. After 12 weeks, 54% of the patients randomized to hydroxyurea had viraemia below 200 copies/ml, compared with 28% on placebo (P < 0.001). Using an ultrasensitive assay with a limit of detection of 20 copies/ml, 19% of patients receiving hydroxyurea had viraemia levels below 20 copies/ml, compared with 8% on placebo (P = 0.05). Mean decrease in HIV-1 RNA was 2.3 and 1.7 log10 copies/ml for hydroxyurea and placebo groups, respectively (P = 0.001). Hydroxyurea was found to induce lymphopenia (-124 x 10(6)/l). Increase in CD4 cell counts was +28 x 10(6)/l during hydroxyurea treatment compared with +107 x 10(6)/l on placebo (P = 0.001).. Hydroxyurea improved the antiviral activity of d4T and ddl over a 12-week period, but was associated with a smaller increase in CD4 cell counts due to hydroxyurea-induced lymphopenia.

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; Cohort Studies; Didanosine; Double-Blind Method; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; Hydroxyurea; Middle Aged; Prospective Studies; RNA, Viral; Stavudine; Switzerland; Viremia

Topics: CD4 Lymphocyte Count; Didanosine; Drug Therapy, Combination; HIV Infections; Humans; Hydroxyurea; RNA, Viral; Treatment Outcome; Viremia; Zidovudine

The pattern of mutations in the reverse transcriptase (RT) of human immunodeficiency virus type 1 (HIV-1) strains that confer resistance to didanosine (ddI) was analyzed in 2 groups of patients receiving either ddI monotherapy or ddI plus hydroxyurea (HU) combination therapy. Twelve patients receiving combination therapy and 8 receiving monotherapy were tested. Combinations of ddI plus HU did not prevent the onset of mutations, which emerged in 50% of the patients in this group compared with 25% of the ddI monotherapy group. In addition, in 1 patient from the combination therapy arm, who had a limited response to the therapy, an unusual pattern of mutations was found: the insertion of 2 amino acids between residues 69 and 70, a region critical for resistance to nucleoside analogs. The higher efficacy of the combination of HU and ddI compared with that of ddI monotherapy cannot be attributed to a delayed or decreased onset of resistance to ddI.

Topics: Anti-HIV Agents; Didanosine; DNA, Complementary; Drug Resistance, Microbial; Drug Therapy, Combination; Genes, pol; Genes, Viral; HIV Infections; HIV-1; Humans; Hydroxyurea; Mutagenesis, Insertional; Nucleic Acid Synthesis Inhibitors; Polymerase Chain Reaction; RNA, Viral; Sequence Alignment; Sequence Analysis, DNA; Sequence Homology, Amino Acid; Viremia

Combinations of drugs targeting viral proteins have been used to limit or control drug resistance, which is the most important cause of treatment failure in HIV-1-infected individuals. We suggest an alternative approach, namely to target cellular proteins, which are less prone to mutations than viral proteins. Here we show that simultaneous inhibition of a cellular protein (by hydroxyurea) and a viral protein (by ddI) produces a consistent and sustained suppression of HIV-1 for as long as 40 weeks in the absence of virus rebound. We identified the mechanism to explain this lack of rebound: although the combination of the two drugs did not prevent the emergence of mutant viral strains resistant to didanosine (ddI) in these patients, the mutants were still sensitive to standard doses of ddI in the presence of hydroxyurea. These in vivo results were consistent with our in vitro observations: HIV-1 molecular clones resistant to ddI were rendered sensitive to this drug (at concentrations routinely achievable in vivo) after addition of hydroxyurea. This phenomenon can be explained by the observation that hydroxyurea decreases the level of dATP, the cellular competitor of ddI. A low level of dATP favors the incorporation of ddI, even if the viral reverse transcriptase is resistant to this nucleoside analog. This is a novel mechanism of control of resistance and it explains the efficacy of a treatment that is well tolerated, simple, and inexpensive.

Topics: Acquired Immunodeficiency Syndrome; Anti-HIV Agents; CD4 Lymphocyte Count; Cells; Didanosine; Dose-Response Relationship, Drug; Drug Therapy, Combination; Evaluation Studies as Topic; HIV-1; Humans; Hydroxyurea; Leukocytes, Mononuclear; Time Factors; Viremia; Virus Replication

A phase-I study was conducted to examine the safety, pharmacokinetics, and activity of combination 2',3'-dideoxyinosine (ddI) and ribavirin against human immunodeficiency virus type 1 (HIV-1)-positive individuals with CD4+ cell counts of < or = 500/microliter. Nineteen patients were enrolled into the study in which ddI monotherapy (200 mg p.o.b.i.d.) was administered for the first 4 weeks, followed by the coadministration of ribavirin (600 mg p.o.q.d.) and ddI (200 mg p.o.b.i.d.) for 8 or 20 additional weeks. The combination regimen was safe and well tolerated. Three patients did not complete 12 weeks of the study because of adverse events or voluntary withdrawal. The pharmacokinetic studies performed at weeks 4, 6, and 12 on specimens collected from the 15 individuals who completed 12 weeks of therapy revealed no pharmacokinetic interaction between ddI and ribavirin. A significant decline from baseline in HIV-1 titer as measured by quantitative HIV-1 culture was detected both during the ddI-monotherapy phase (week 4, p < 0.001) and during the combination-therapy ddI + ribavirin phase (week 12, p < 0.001); the median drop observed was 0.90 log10 at week 4 and 0.92 log10 at week 12. While the addition of ribavirin did not result in further reductions in viremia in the following weeks on study treatment, 13 (81%) of the 16 patients had at least a -0.5 log10 change in viral titer at week 12. The median decline in plasma viral RNA was 0.68 log10 at week 4(p < 0.001) and 0.67 log10 at week 12 (p = 0.005). CD4+ cell counts increased above baseline significantly during the ddI-monotherapy phase of the study (p = 0.0038). The median increase was +26 cells/mm3 at week 4 and +11 cells/mm3 at week 12; for patients who remained on treatment through 24 weeks, the median CD4+ cell count increase was +10 cells/mm3. The L74V ddI resistance-conferring HIV-I reverse-transcriptase mutation emerged in 53% of the patients. Patients with non-syncytium-inducing HIV variants demonstrated greater responses to treatment with larger decreases in virus load and greater increases in CD4+ cell count. Our results reveal that the combination of ddI and ribavirin in HIV-positive patients is safe, well tolerated, without adverse pharmacologic interaction, and associated with significant and sustained declines in virus load over 12 weeks of therapy.

Topics: Adult; Anti-HIV Agents; Antiviral Agents; CD4 Lymphocyte Count; Didanosine; Drug Interactions; Drug Therapy, Combination; Female; Genetic Variation; Giant Cells; HIV Infections; HIV-1; Humans; Male; Middle Aged; Ribavirin; RNA, Viral; Viremia

Although several immunologic and virologic markers measured in peripheral blood are useful for predicting accelerated progression of human immunodeficiency virus (HIV) disease, their validity for evaluating the response to antiretroviral therapy and their ability to accurately reflect changes in lymphoid organs remain unclear. In the present study, changes in certain virologic markers have been analyzed in peripheral blood and lymphoid tissue during antiretroviral therapy. Sixteen HIV-infected individuals who were receiving antiretroviral therapy with zidovudine for > or = 6 months were randomly assigned either to continue on zidovudine alone or to add didanosine for 8 weeks. Lymph node biopsies were performed at baseline and after 8 weeks. Viral burden (i.e., HIV DNA copies per 10(6) mononuclear cells) and virus replication in mononuclear cells isolated from peripheral blood and lymph node and plasma viremia were determined by semiquantitative polymerase chain reaction assays. Virologic and immunologic markers remained unchanged in peripheral blood and lymph node of patients who continued on zidovudine alone. In contrast, a decrease in virus replication in lymph nodes was observed in four of six patients who added didanosine to their regimen, and this was associated with a decrease in plasma viremia. These results indicate that decreases in plasma viremia detected during antiretroviral therapy reflect downregulation of virus replication in lymphoid tissue.

Topics: Adult; Didanosine; DNA, Viral; Female; HIV Infections; HIV-1; Humans; Lymph Nodes; Lymphocytes; Male; Time Factors; Viremia; Zidovudine

To evaluate the safety and efficacy of didanosine (ddl) monotherapy and three different combinations of zidovudine (ZDV) and ddl in asymptomatic human immunodeficiency virus-1 (HIV-1) infection, we conducted an open-label, phase I/II study in 126 asymptomatic HIV-1-infected hemophilic and nonhemophilic subjects with a CD4 count of 200 to 500/mm3 stratified for prior zidovudine treatment and baseline CD4 count. Study arms included arm A, low-dose combination (ZDV 150 mg and ddl 134 mg, daily); arm B, moderate-dose combination (ZDV 300 mg and ddI 334 mg, daily); arm C, high-dose combination (ZDV 600 mg and ddl 500 mg, daily), and arm D, ddl monotherapy (ddl 500 mg, daily). Earlier, more frequent hepatotoxicity was experienced by hemophilic subjects (P = .008), but there were no differences in toxicity between treatment arms (P = .51), nor were there any differences in the rate of development of clinical endpoints by treatment (P = .41). Smaller median CD4 increases occurred over the first 12 weeks for arms A and D, 44/mm3 and 42/mm3, than arms B and C, 105/mm3 and 114/mm3, respectively, (P = .015). Hemophilia status (P = .0004) and prior ZDV experience (P = .044) independently predicted weaker CD4 responses during the first 12 weeks of treatment. Using a regression model and adjusting for hemophilia status, prior ZDV treatment, and baseline CD4, there was a significant reduction in quantitative viral load from baseline by week 12 for all treatment arms combined (P = .0001), with significantly lower median percent reduction for arm A (56.3%) than arms B, C, and D (94.6%, 98.5%, and 91.9%, respectively, P = .015). Although greater hepatoxicity and weaker CD4 responses occur in hemophilic subjects, didanosine monotherapy and combination therapy with zidovudine are safe and effective in asymptomatic HIV-1-infected patients.

Topics: Adult; CD4 Lymphocyte Count; Chemical and Drug Induced Liver Injury; Didanosine; Drug Therapy, Combination; Female; Hemophilia A; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Male; Safety; Treatment Outcome; Viremia; Zidovudine

The changes in viremia levels and the development of drug-related mutations were examined in 26 patients with symptomatic human immunodeficiency virus type 1 (HIV-1) infection participating in a randomized trial comparing alternating (A) and simultaneous (S) regimens of zidovudine and didanosine therapy. Patients on both arms had significant reduction in serum RNA copies from baseline throughout the 2 years of study. Significant differences between the two arms were demonstrated over the first 2-3 months of therapy. Analyses with nested polymerase chain reaction revealed that the emergence of the didanosine-related position 74 Leu-->Val mutation was significantly blocked in both regimens, while the zidovudine-related mutation at codon 215 was not affected. Determination of the overall durability of the antiviremic effect of the A and S regimens of zidovudine and didanosine and clinical implications of the results require further research.

Topics: Adult; Base Sequence; CD4 Lymphocyte Count; Codon; Didanosine; Drug Resistance, Microbial; Drug Therapy, Combination; Female; Genes, pol; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Male; Middle Aged; Molecular Sequence Data; Mutation; RNA, Viral; Viremia; Zidovudine

Good markers for monitoring the efficacy of antiretroviral therapy in children do not currently exist. This study examined the effect of antiretroviral therapy on human immunodeficiency virus (HIV-1) unintegrated DNA (uDNA), integrated DNA (iDNA), percent uDNA, immune complex dissociated (ICD) p24 antigenemia, and plasma viral titer. Seven children were followed at therapy initiation and at approximately 3- and 10-month intervals. HIV-1 uDNA was detected in all children prior to start of therapy (average percent uDNA, 43%). At 3 months, the percent HIV uDNA decreased in all patients to an average of 18% (p = 0.01) and at 10 months decreased to an average of 1%. In contrast, the amount of HIV iDNA was relatively constant after initiation of therapy. ICD HIV p24 antigen was detected in all patients prior to therapy (average, 538 pg/ml). Over the study period, the ICD p24 antigen level decreased in three patients and remained relatively unchanged in four patients. Plasma cultures of HIV-1 were positive in only one of the seven patients prior to therapy. Among the methods evaluated, measurement of uDNA was the only parameter which reliable decreased after initiation of nucleoside therapy.

Topics: CD4 Lymphocyte Count; Child, Preschool; Didanosine; DNA, Viral; Drug Therapy, Combination; Female; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Infant; Leukocytes, Mononuclear; Male; Polymerase Chain Reaction; Viremia; Zidovudine

2'3'-Dideoxyinosine (didanosine) is a nucleoside analog active in vitro against human immunodeficiency virus. Few data are available regarding its use for the treatment of children. In a single-center, randomized, open-label trial, we compared two dosages of didanosine (120 vs 270 mg/m2 per day) for at least 6 months in 34 children infected with human immunodeficiency virus who had become resistant to or were intolerant of zidovudine. Serum levels of didanosine 1 hour after administration were significantly different in the two groups and remained stable with time. There was a significant reduction in human immunodeficiency virus-p24 antigenemia and quantitative cellular viremia with time but no difference between the two groups. The intensity of the biologic response, however, was significantly higher in the patients who had more than 50 CD4+ cells 10(6)/L at inclusion. No pancreatic or neurologic toxic effects were observed. In five children, liver function abnormalities developed that are unusual in this setting, and the death of one child from unexplained hepatocellular failure suggests that didanosine may be hepatotoxic. Three of these five children had preexisting liver disease. Although no definite conclusion can be made as to the optimal dose, there were no major differences between the two administration schedules in terms of biologic effects and tolerability.

Topics: Adolescent; Child; Child, Preschool; Didanosine; Female; HIV; HIV Core Protein p24; HIV Infections; Humans; Infant; Male; Viremia

Topics: Adult; Anti-HIV Agents; Didanosine; Female; Hepacivirus; Hepatitis C, Chronic; HIV Infections; Humans; Pregnancy; Pregnancy Complications, Infectious; Remission, Spontaneous; Viremia; Zidovudine

Topics: Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; CD4-CD8 Ratio; Depression; Didanosine; HIV Infections; HIV Protease Inhibitors; HIV-1; Humans; Infectious Mononucleosis; Male; Reverse Transcriptase Inhibitors; Ritonavir; Stavudine; Treatment Refusal; Trimethoprim, Sulfamethoxazole Drug Combination; Viral Load; Viremia; Zalcitabine; Zidovudine

Major T-cell receptor beta chain variable region (TCRBV) repertoire perturbations are temporally associated with the down-regulation of viremia during primary human immunodeficiency virus (HIV) infection and with oligoclonal expansion and clonal exhaustion of HIV-specific cytotoxic T lymphocytes (CTLs). To determine whether initiation of antiretroviral therapy (ART) or highly active antiretroviral therapy (HAART) during primary infection influences the dynamics of T-cell-mediated immune responses, the TCRBV repertoire was analyzed by semiquantitative polymerase chain reaction in serial blood samples obtained from 11 untreated and 11 ART-treated patients. Repertoire variations were evaluated longitudinally. Stabilization of the TCRBV repertoire was more consistently observed in treated as compared with untreated patients. Furthermore, the extent and the rapidity of stabilization were significantly different in treated versus untreated patients. TCRBV repertoire stabilization was positively correlated with the slope of HIV viremia in the treated group, suggesting an association between repertoire stabilization and virologic response to treatment. To test whether stabilization was associated with variations in the clonal complexity of T-cell populations, T-cell receptor (TCR) heteroduplex mobility shift assays (HMAs) were performed on sequential samples from 4 HAART-treated subjects. Densitometric analysis of HMA profiles showed a reduction in the number of TCR clonotypes in most TCRBV families and a significant decrease in the total number of clonotypes following 7 months of HAART. Furthermore, a biphasic decline in HIV-specific but not heterologous CTL clones was observed. This indicates that ART leads to a global reduction of CD8(+) T-cell oligoclonality and significantly modulates the mobilization of HIV-specific CTL during primary infection. (Blood. 2000;95:1743-1751)

Topics: Acute Disease; Anti-HIV Agents; Clone Cells; Didanosine; Drug Administration Schedule; Drug Therapy, Combination; Gene Rearrangement, beta-Chain T-Cell Antigen Receptor; HIV Infections; HIV Protease Inhibitors; HIV Reverse Transcriptase; HIV-1; Humans; Indinavir; Lamivudine; Lymphocyte Activation; Polymerase Chain Reaction; RNA-Directed DNA Polymerase; Saquinavir; T-Lymphocytes, Cytotoxic; Viremia; Zidovudine

Topics: Anti-HIV Agents; Didanosine; Drug Therapy, Combination; Enzyme Inhibitors; HIV Infections; Humans; Hydroxyurea; Palliative Care; Viremia

In a randomized controlled trial with acute simian immunodeficiency virus (SIV)-infected macaques, both highly active antiretroviral therapy (HAART) and HAART with fixed-schedule structured treatment interruption (STI-HAART; alternating 3 weeks on and 3 weeks off therapy) suppressed viral load. In the STI-HAART group, T cell virus-specific immune response (VIR) and control of viral rebound increased concurrently during subsequent interruptions. In contrast, VIR did not increase and SIV rebounded after permanent treatment withdrawal in all animals on continuous HAART. Fixed-schedule STI-HAART appears to be an effective alternative to continuous HAART for the early treatment of retroviral infection.

Topics: Adenine; Animals; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; CD4 Lymphocyte Count; CD8-Positive T-Lymphocytes; Didanosine; Drug Administration Schedule; Hydroxyurea; Lymphocyte Activation; Macaca mulatta; Organophosphonates; Organophosphorus Compounds; Random Allocation; Simian Acquired Immunodeficiency Syndrome; Simian Immunodeficiency Virus; Tenofovir; Viral Load; Viremia; Virus Replication

Topics: CD4 Lymphocyte Count; Child; Child, Preschool; Didanosine; Drug Resistance, Microbial; Drug Therapy, Combination; Female; HIV Infections; HIV Protease Inhibitors; HIV Reverse Transcriptase; HIV-1; Humans; Infant; Male; Mutation; Reverse Transcriptase Inhibitors; Ritonavir; Viremia; Zidovudine

(i) To investigate whether protease inhibitor (PI) (nelfinavir)-containing highly active antiretroviral therapy (HAART) affects body composition differently in HIV-infected and AIDS patients without wasting syndrome. (ii) To delineate the changes in resting energy expenditure (REE) under PI therapy, and to determine whether sustained reductions in HIV RNA would decrease REE.. Prospective longitudinal cohort study with individually matched healthy controls.. Tertiary care centre at a University Hospital.. HIV-seropositive (n = 20) and AIDS patients (n = 17) with a plasma viral load of at least 10000 copies/ml and 37 healthy volunteers were enrolled. All participants were weight stable, free of acute opportunistic infections, and naive to PI therapy. Patients underwent testing of bioelectrical impedance analysis (BIA), indirect calorimetry and food intake, shortly before the initiation of HAART and 24 weeks thereafter.. Both patient groups gained weight, body mass index (BMI), and fat-free mass (FFM) (P < 0.05 versus baseline), whereas only AIDS patients gained fat mass. Increases were more pronounced in the AIDS group. REE was elevated compared with corresponding controls at baseline, and decreased similarly in HIV and in AIDS patients during PI therapy (P < 0.05). The reduction in the viral burden preceded the decrease in REE by several weeks.. Body composition and metabolic parameters improved during PI therapy in HIV-infected and AIDS patients without wasting. Although an early reduction in viral load as a result of HAART does not seem to influence REE directly, sustained viral load suppression may promote a decrease in energy expenditure.

Topics: Acquired Immunodeficiency Syndrome; Adult; Basal Metabolism; Body Composition; Body Weight; Case-Control Studies; Cohort Studies; Didanosine; Energy Metabolism; Female; HIV Infections; HIV Protease Inhibitors; Humans; Longitudinal Studies; Male; Middle Aged; Nelfinavir; Prospective Studies; Stavudine; Viremia

To evaluate the clinical and biological impact of protease inhibitors on HIV-associated Kaposi's sarcoma.. A cohort of 10 patients included prospectively from April 1996 to June 1997 were studied in one institutional centre after initiation of protease inhibitors.. All patients but one (stable disease) had progressive Kaposi's sarcoma. Three out of 10 patients had stopped specific chemotherapy for Kaposi's sarcoma for more than 4 weeks, three were still under chemotherapy, and four had never received specific treatment of Kaposi's sarcoma. Plasma HIV viral load, human herpesvirus (HHV)-8 viraemia in peripheral blood mononuclear cells (PBMC), and CD4 cell count were sequentially assessed from the beginning of therapy. For six patients, a semiquantitative evaluation of HHV-8 viral load in the Kaposi's sarcoma lesions was performed during treatment using polymerase chain reaction.. After initiation of HIV triple therapy with protease inhibitors, we observed six complete responses, two partial responses, and two patients with progressive disease. All patients had undetectable plasma HIV viral load within 2 months of treatment. Undetectable HHV-8 viraemia in PBMC occurred in seven out of eight patients with partial or complete response and in none of the progressive patients. A decrease or negation of HHV-8 viral load in Kaposi's sarcoma lesions was observed in two complete responders.. Our results suggest that antiviral therapy with protease inhibitors are clinically efficient in HIV-associated Kaposi's sarcoma and that there exists a correlation between clinical response and negation of HHV-8 viraemia.

Topics: Adult; AIDS-Related Opportunistic Infections; Anti-HIV Agents; Didanosine; Dideoxynucleosides; Drug Therapy, Combination; Female; Herpesvirus 8, Human; HIV Protease Inhibitors; Humans; Indinavir; Lamivudine; Male; Middle Aged; Prospective Studies; Reverse Transcriptase Inhibitors; Ritonavir; Saquinavir; Sarcoma, Kaposi; Stavudine; Treatment Outcome; Viral Load; Viremia; Zalcitabine; Zidovudine

We compared the QUANTIPLEX HIV-1 RNA 2.0 assay with the AMPLICOR HIV-1 MONITOR 1.0 assay for quantitation of human immunodeficiency virus type 1 (HIV-1) RNA in plasma in the Stadi trail, which evaluated a stavudine plus didanosine combination therapy in 52 patients. HIV-1 RNA baseline values measured with AMPLICOR HIV-1 MONITOR 1.0 were significantly higher than those measured with QUANTIPLEX HIV-1 RNA 2.0, and decreases in HIV-1 RNA levels from baseline were also found to be significantly higher when measured with the AMPLICOR HIV-1 MONITOR 1.0 assay. The frequency of HIV-1 RNA levels below the lower limit of quantitation was significantly higher with QUANTIPLEX HIV-1 RNA 2.0 than with AMPLICOR HIV-1 MONITOR 1.0. Reanalysis of these results by an ultrasensitive procedure of AMPLICOR HIV-1 MONITOR 1.0 or by a modified version of the test that included additional primers adapted for non-B HIV-1 clades yielded greater differences between the QUANTIPLEX HIV-1 RNA 2.0 assay and the AMPLICOR HIV-1 MONITOR 1.0 assay. Our results indicate that a valid comparison of the virological efficacies obtained with different antiretroviral drug regimens requires the use of the same viral load quantitation procedure; further standardization between the different HIV-1 RNA quantitation kits is therefore needed.

Topics: Anti-HIV Agents; Didanosine; Drug Therapy, Combination; Evaluation Studies as Topic; HIV Infections; HIV-1; Humans; RNA, Viral; Stavudine; Viremia; Virology

To assess human immunodeficiency virus (HIV) ribonucleic acid load in children and adolescents with HIV infection who are being treated with antiretroviral combination therapy.. Five patients whose disease progressed with their prior antiretroviral therapy had treatment regimens changed to zidovudine (ZDV)/didanosine (DDI) (group A), and the regimens of six patients were changed to ZDV/lamivudine (3TC) (group B). Patients were followed every 4 to 8 weeks for an average period of 8.6 months. Serial determinations of viral copy numbers and CD4 cells were performed.. In group A patients' mean relative changes in CD4 cells showed a 20% increase after 4 months (difference not significant (NS)) and a return to baseline after 8 months; in group B patients' mean relative increases of CD4 cells were 72% (p = 0.046) and 50% (NS), respectively. In group A mean relative viral load increased 21% (0.08 log10, NS) and 71% (0.23(10) log, NS), whereas in group B viral load decreased 22% (0.1 log10, NS) and 74% (0.58 log10, p = 0.03) after 4 and 8 months, respectively. After starting antiretroviral combination therapy in group A, there was a slight trend of a decreasing ratio of viral load per number of CD4 cells, whereas in group B this ratio significantly decreased, indicating a marked suppression of viral turnover with ZDV/3TC treatment.. In a small cohort of pediatric patients, combination therapy with ZDV/3TC was well tolerated and had a strong and sustained effect on the decrease of viral loads similar to results obtained in adults. In patients with ZDV/DDI therapy the reduction of viral load was less pronounced, but treatment groups A and B were not comparable for statistic evaluation.

Topics: Adolescent; AIDS-Related Opportunistic Infections; Anti-HIV Agents; CD4 Lymphocyte Count; Child; Child, Preschool; Didanosine; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Infant; Lamivudine; Male; RNA, Viral; Time Factors; Viral Load; Viremia; Zidovudine

To determine the influence of HIV-1 replication on immunologic decline and clinical outcome, we quantified the HIV-1 plasma viral load in 20 patients at different times over a mean period of 10.8 months. Quantitation was performed by branched DNA signal amplification (bDNA) and p24 antigenemia. Immunologic status was assessed through beta 2-microglobulin and CD4+ cell count determinations. CD4+ cell decline was expressed as a slope of the regression line constructed by the logarithms of CD4+ cell count observations. Mean values of plasma viral load were correlated with CD4+ cell decline and mean beta 2-microglobulin levels. Significant correlation was observed between plasma viral load quantified by the bDNA technique and CD4+ cell decline. No significant correlation was observed between plasma viral load quantified by p24 antigenemia and CD4+ cell decline. A significant correlation was observed between plasma viral load and beta 2-microglobulin levels. Immunologic decline was better predicted from HIV-1 RNA levels than from the CD4+ cell count. Significantly higher plasma viral load was observed in patients who had clinical progression of HIV-1 infection. Thus, HIV-1 plasma viral load quantified by a highly reliable technique such as bDNA showed that the immunologic decline is closely related to HIV-1 RNA replication.

Topics: Anti-HIV Agents; beta 2-Microglobulin; CD4 Lymphocyte Count; Didanosine; Disease Progression; DNA, Viral; Drug Therapy, Combination; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Longitudinal Studies; RNA, Viral; Stavudine; Viral Load; Viremia; Virus Replication; Zalcitabine; Zidovudine

To assess the antiretroviral effect of a combination of zidovudine, didanosine, lamivudine and saquinavir in plasma, peripheral blood mononuclear cells (PBMC) and lymph-node mononuclear cells (LNMC) after 8 weeks.. Ten HIV-1 antiretroviral therapy-naive patients were given a combination of oral zidovudine (200 mg three times daily), oral didanosine (200 twice a day), oral lamivudine (150 mg twice a day) and oral saquinavir (600 mg three times daily). HIV-1 plasma RNA was measured by quantitative reverse transcriptase (RT)-polymerase chain reaction (PCR). Infectious HIV-1 in PBMC and LNMC was measured by a coculture technique. HIV-1 RNA in PBMC and LNMC was quantified by RT-PCR. Proviral DNA titres in PBMC and LNMC were measured by endpoint dilution PCR. CD4 T-cells were analysed by flow cytometry.. CD4 cell counts rose in all patients (mean increase of 125 +/- 71 CD4 cells x 10(6)/l) and the benefit was greater for patients with fewer than 350 CD4 cells x 10(6)/l (mean increase of 159 +/- 74 CD4 cells x 10(6)/l). Plasma HIV-1 RNA decreased exponentially in all patients (mean decrease of 3.1 log10 after 8 weeks with a mean half-life of 2.2 +/- 0.6 days). HIV-1 RNA showed a decrease of 3.07 log10 in PBMC and of 2.1 log10 in LNMC. The decrease in plasma HIV-1 RNA was consistently associated with the decrease in LNMC. These data were supported by a concomitant drop of HIV-1 infectious titres in PBMC (mean decrease of 1.41 log10) and in LNMC (mean decrease of 2.54 log).. These data show a significant antiretroviral effect of this four-drug combination in blood and lymphoid tissues. However, a greater decrease in HIV-1 RNA was observed in PBMC and in plasma than in lymph node cells.

Topics: Adult; Anti-HIV Agents; CD4 Lymphocyte Count; Didanosine; DNA, Viral; Drug Therapy, Combination; Female; HIV Infections; HIV-1; Humans; Lamivudine; Leukocytes, Mononuclear; Lymph Nodes; Male; Polymerase Chain Reaction; RNA, Viral; Saquinavir; Viral Load; Viremia; Zidovudine

TNF-alpha is involved in the pathogenesis of HIV, and is known to enhance HIV replication in vitro. In this report the kinetics of plasma TNF-alpha and sTNFRII in patients receiving aggressive antiretroviral therapy and their relationship to HIV plasma RNA and CD4 cell counts were examined. Eleven patients participating in an open label study for assessment of safety, and of virological and immunological effects of simultaneous treatment with d4T, ddI, and HU, were evaluated. The CD4 cell count of the patients before treatment ranged from 65 to 374/mm3 and their HIV plasma RNA ranged from 1.9 x 10(4) to 3.7 x 10(5) copies/ml. The viral load in eight patients decreased significantly (mean, 1.9 log10). TNF-alpha and sTNFRII plasma levels pretreatment and at 8 weeks into therapy directly correlated with HIV plasma RNA. Pretreatment circulating TNF-alpha levels of 25-114 pg/ml (mean, 56 pg/ml) decreased by more than twofold in seven patients. The change in TNF-alpha levels inversely correlated with the change in absolute CD4 cell number. Detailed kinetics of TNF-alpha and sTNFRII measured at weeks 0, 1, 2, 4, 6, 8, and 12 paralleled those of HIV plasma RNA. A rapid decline in these soluble markers was always observed at week 1 together with the HIV plasma RNA response. Three patients maintained a high viral load as well as high TNF-alpha and sTNFRII. These data suggest that (1) combination therapy with d4T, ddI, and HU decreased viral load and circulating levels of TNF-alpha/sTNFRII; (2) an association exists between the TNF-alpha/sTNFRII and HIV viral load; and (3) TNF-alpha/sTNFRII might be a useful surrogate marker for predicting efficacy of antiretroviral therapy.

Topics: Adult; Anti-HIV Agents; Antigens, CD; CD4 Lymphocyte Count; Didanosine; Drug Therapy, Combination; Female; HIV Infections; Humans; Hydroxyurea; Kinetics; Male; Middle Aged; Receptors, Tumor Necrosis Factor; Receptors, Tumor Necrosis Factor, Type II; Reverse Transcriptase Inhibitors; Solubility; Stavudine; Tumor Necrosis Factor-alpha; Viremia

Although CD4+ T cells are the main target of HIV infection, CD8+ cells also play important roles in the interaction between HIV and the host immune system. The aim of this study was to analyze the effect of anti-HIV therapy on the relative proportion of some important CD8+ cell subpopulations. Five HIV-infected patients were enrolled, and blood samples were collected several times, within 90 days from the initiation of therapy. CD4+ cell count and HIV viremia were investigated, as well as the expression of CD38, HLA-DR, CD28, CD57, CD30, CD95 molecules on CD8+ cells. A complex remodeling of CD8+ cell subpopulations took place between week 2 and week 7 of treatment. This remodeling mainly consisted of: i) decrease of CD8+CD38+ and CD8+DR+ cells; ii) increase of CD8+CD28+ cells; and iii) decreased expression of the CD95/Fas molecule on CD8+ cells. Overall, these findings suggest that effective anti-HIV therapy induces changes of CD8+ subpopulations showing the reversal of the state of chronic activation that is caused by viral replication.

Topics: Adult; Anti-HIV Agents; CD8-Positive T-Lymphocytes; Cell Count; Didanosine; Drug Therapy, Combination; Flow Cytometry; HIV Seropositivity; HIV-1; Humans; Male; Phenotype; RNA, Viral; Viremia; Zidovudine

As lymphoid organs are the major reservoir of human immunodeficiency virus type 1 (HIV-1), the rates at which HIV-1 RNA decreases from the plasma and from a series of lymph node biopsies from 4 patients treated with a combination of zidovudine, didanosine, and lamivudine were measured. The concentrations of HIV-1 RNA in the plasma and in lymph nodes declined exponentially, with mean half-lives of 1.88 +/- 0.86 days for plasma and 6.01 +/- 3.44 days for lymph nodes. These data show that most of the HIV-1 in lymphoid organs is due to the infection of new cells and demonstrate that a triple-drug combination is able to target this compartment.

Topics: Antiviral Agents; Biopsy; Didanosine; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; Kinetics; Lamivudine; Lymph Nodes; RNA, Viral; Viremia; Zalcitabine; Zidovudine

Lymph nodes serve as reservoirs for the replication of human immunodeficiency virus (HIV) type 1. Comparison of serial measurements of virus burden in lymph nodes and peripheral blood after a change in antiretroviral therapy may provide insights into pathogenic mechanisms and permit a more accurate assessment of a therapeutic response.. Nevirapine was added to the drug regiment of eight children with HIV infection treated with the combination of zidovudine and didanosine who had increasing levels of serum p24 antigen. Lymph node biopsies were performed at entry and after 12 weeks of therapy.. Neither CD4 counts nor p24 antigen level correlated with the degree of viremia as measured by ribonucleic acid copy numbers in plasma. Correlations were found between HIV DNA copy number in peripheral blood mononuclear cells and HIV DNA copy number in lymph nodes (p = 0.02), as well as between peripheral blood CD4 counts and lymph node architecture. The HIV signals in the lymph nodes conformed to the anatomic organization of apical light zones in the germinal centers; however, in more advanced disease stages, organized germinal centers disappeared as evidence by a decline in the extent of the follicular dendritic network.. Lymph node biopsies in this small number of HIV-infected children revealed a progressive loss of an organized architecture, especially of the follicular dendritic network. This correlated with a progressive loss of CD4+ cells but not with other measures of disease stage, including viral load, as measured by ribonucleic acid copy numbers.

Topics: Antiviral Agents; Biopsy; CD4 Lymphocyte Count; Child; Child, Preschool; Didanosine; DNA, Viral; Drug Therapy, Combination; Female; HIV Core Protein p24; HIV Infections; HIV-1; Humans; In Situ Hybridization; Infant; Lymph Nodes; Male; Nevirapine; Pyridines; Viremia; Zidovudine

To determine the following: (1) the feasibility of combining the antiretroviral didanosine (ddl) with a 96-hour continuous intravenous (IV) infusion of cyclophosphamide (800 mg/m2), doxorubicin (50 mg/m2), and etoposide (240 mg/m2) (CDE) plus filgrastim in patients with non-Hodgkin's lymphoma (NHL) associated with human immunodeficiency virus (HIV) infection; (2) the effect of ddl on CDE-induced myelosuppression and CD4 lymphopenia; and (3) the effect of CDE on serum p24 antigen and quantitative HIV blood cultures.. Twenty-five patients with HIV-related NHL received CDE every 28 or more days. Consecutive patients were assigned in an alternating fashion to group A (ddl given at a standard dose during cycles one, two, five, and six) or group B (ddl given during cycles three, four, five, and six).. ddl use was associated with less leukopenia (mean nadir, 3.33 v 1.49 x 10(3)/microL; p = .03), neutropenia (2.38 v 1.07 x 10(3)/microL; p = .03), and thrombocytopenia (76 v 48 x 10(3)/microL; p = .059), and fewer RBC (1.6 v 3.1 per cycle; p < .01) and platelet transfusions (0.7 v 1.5 per cycle; p < .01), but had no significant effect on CD4 lymphopenia. Furthermore, lymphomatous bone marrow involvement and low CD4 count were associated with significantly greater myelosuppression. Although there was no substantial change in serum p24 antigen, the HIV blood culture became quantitatively more positive or converted from negative to positive in seven patients (64%). Complete response (CR) occurred in 58% of patients (95% confidence interval, 38% to 78%), median CR duration exceeded 18 months, tumor-related mortality was 20%, and median survival was 18.4 months.. Our results suggest that the CDE and filgrastim regimen is tolerable and effective for patients with HIV-associated NHL, and that combination with ddl is feasible and may result in less myelosuppression.

Topics: Acquired Immunodeficiency Syndrome; Adult; Anti-HIV Agents; Antineoplastic Combined Chemotherapy Protocols; CD4 Lymphocyte Count; Cyclophosphamide; Didanosine; Doxorubicin; Etoposide; Female; Filgrastim; Granulocyte Colony-Stimulating Factor; HIV; HIV Core Protein p24; Humans; Lymphoma, AIDS-Related; Lymphoma, Non-Hodgkin; Male; Middle Aged; Pilot Projects; Recombinant Proteins; Survival Rate; Viremia

Methods for the absolute quantitation of nucleic acids present in small amounts in biological samples (competitive PCR and competitive reverse transcription PCR) were applied to the direct monitoring of specific anti-human immunodeficiency virus type 1 (HIV-1) therapy. With these techniques, different parameters of HIV-1 activity (including genomic RNA copy numbers in plasma, proviral and late transcript copy numbers in peripheral blood lymphocytes, and mean transcriptional activity per each HIV-1 provirus) were monitored during therapy with azidothymidine or ddI. In most of these treated patients, a direct response to the antiretroviral compounds employed was detected during the first few weeks of treatment, as documented by a fast decrease of all molecular indexes of HIV-1 activity. However, residual viral replication (albeit at minimal levels) was documented during therapy in all subjects monitored in this study. In a minority of the patients under study (3 of 12), the drug-dependent viral inhibition was maintained throughout the observation time (213 to 791 days), but in 9 patients a rebound in viremia level was detected during therapy with competitive reverse transcription PCR. Sequencing analysis of a portion of the HIV-1 gene pol from cell-free virions showed that circulating viral variants bearing at least two mutations compatible with azidothymidine or ddI resistance were detectable in the patients who exhibited a rebound in cell-free HIV-1 genomic RNA copy numbers in plasma but not in one patient who maintained (for 455 days) lowered levels of viral load during ddI treatment.

Topics: Amino Acid Sequence; Didanosine; DNA, Viral; Female; Genes, pol; HIV Infections; HIV-1; Humans; Leukocytes, Mononuclear; Male; Molecular Sequence Data; Mutagenesis; RNA, Viral; Sequence Analysis, DNA; Transcription, Genetic; Viremia; Zidovudine

To evaluate whether early changes in viraemia in response to didanosine (ddI) predict death and occurrence of new AIDS-defining events.. Forty-three patients were followed during ddI treatment with sequential determinations of serum viraemia, mutations associated with drug resistance, CD4 counts and clinical evaluation. Patients were stratified into two groups of equal size, responders and nonresponders, using the median of individual changes in viraemia 1 month after initiation of ddI therapy.. After 1 month of ddI, mean viraemia decreased by 0.35 log RNA copies/ml of serum (P < 0.001) in the population. A significant difference in survival (median, 14 and 35 months in nonresponders and responders, respectively; log rank, P = 0.004) and in the delay to the occurrence of new AIDS-defining events (median, 8 and 33 months in nonresponders and responders, respectively; log rank, P = 0.018) was observed. After stratification for presence of AIDS before starting ddI, viraemia response at 1 month remained predictive of both overall and AIDS-defining event-free survival (log rank, P = 0.0006 and P = 0.01). After a similar stratification for initial CD4, viraemia response still predicted overall survival (log rank, P = 0.009), but its predictive value for AIDS-defining event-free survival did not reach statistical significance (P = 0.12). High initial levels of HIV RNA, presence of mutation 215 or previous duration of zidovudine therapy were not predictive of survival.. In patients treated with ddI, changes in viraemia at 1 month predict survival independently of initial AIDS diagnosis and initial CD4 counts.

Topics: Acquired Immunodeficiency Syndrome; Didanosine; Follow-Up Studies; HIV; Humans; Prognosis; RNA, Viral; Survivors; Viremia

Fourteen patients previously treated with zidovudine were monitored for laboratory parameters and clinical events during 1 year after introduction of didanosine (ddI) monotherapy. Proviral human immunodeficiency virus type 1 (HIV-1) copy numbers (cell-associated DNA) and concentration of free virions (viremia) were determined using a semiquantitative polymerase chain reaction (PCR). High levels of circulating virus were detected in all patients (range, 17 to 5,934 x 10(3)/ml of serum). Within 4 weeks of therapy, a decrease of viremia (60 to 98%) was observed in nine patients. After 1 year of treatment, eight of these nine patients still had decreased viremia when proviral HIV DNA was decreased or stable, and CD4+ lymphocytes were stable or higher in seven of these eight patients. Antiviral effect was more pronounced in the six patients with CD4+ > 100/mm3 at entry, five of them belonging to the subgroup of the seven responding patients as compared to two of eight patients with CD4+ < 100/mm3. Clinical events in this small group were not statistically correlated with virologic parameters; however, responding patients had a tendency to stabilize or gain weight. This study suggests that measurement of viremia deserves further study as a marker of antiviral efficacy and might predict, even at 4 weeks, the beneficial potential of ddI.

Topics: AIDS-Related Opportunistic Infections; CD4 Lymphocyte Count; Didanosine; DNA, Viral; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Polymerase Chain Reaction; Proviruses; RNA, Viral; Viremia; Virion; Zidovudine

Topics: Acquired Immunodeficiency Syndrome; Didanosine; Drug Therapy, Combination; Enzyme Inhibitors; HIV Infections; HIV-1; Humans; Hydroxyurea; Viremia

The clinical significance and public health implications for HIV pathogenesis due to resistance to antiretroviral agents, such as AZT, ddI, ddC, d4T, 3TC, are discussed. Several studies are highlighted, showing that AZT resistance is associated with more rapid clinical progression and death. AZT-resistant viruses are quite tough, and once established, become the dominant circulating quasi-species. Other studies show that the clinical significance of resistance to the dideoxynucleosides (ddI, ddC, d4T, and 3TC) remains incompletely understood. The article notes that, despite widespread clinical practice of using combination treatment regimens, no study has proven that combination therapy delays HIV disease progression or death over the long term. Public health considerations include the proven problem of human- to-human transmission of AZT-resistant HIV.

Topics: Antiviral Agents; CD4 Lymphocyte Count; Didanosine; Drug Resistance, Microbial; Drug Resistance, Multiple; Drug Therapy, Combination; HIV Infections; HIV-1; Humans; Lamivudine; RNA, Viral; Stavudine; Viremia; Zalcitabine; Zidovudine

We evaluated the stability of human immunodeficiency virus (HIV) load markers from blood samples collected in VACUTAINER CPT or standard VACUTAINER brand tubes using sodium heparin or sodium citrate as anticoagulants. Quantitative plasma culture and p24 antigen concentrations were determined, and HIV RNA levels in plasma were measured by both reverse transcription-PCR-enzyme-linked immunosorbent assay (RT-PCR-ELISA) and branched DNA methods. All tubes were stored at room temperature for analysis at 2, 24, 48, and 72 h after the blood samples were drawn. No difference was seen between tube types with respect to the HIV titer in plasma or the positivity rate for all samples that demonstrated a fall in titer over time. Unbound p24 antigen levels in plasma decreased during the initial 48-h period in both tube types. Immune complex-dissociated p24 antigen levels decreased in CPT tubes but not in standard VACUTAINER tubes. The HIV RNA copy number in plasma measured by RT-PCR-ELISA was stable in most subjects and was significantly higher in CPT tubes than in standard VACUTAINER tubes at 24 and 72 h after the blood samples were drawn. The branched DNA probe assay detected a significant decline in HIV RNA equivalent in plasma over 72 h in both collection tubes, the decline being more dramatic in the standard VACUTAINER tube than the CPT tube. Overall, interday variability suggests that samples collected for a particular assay should be processed at the same time after blood is drawn and that a particular tube type be used throughout a given study.

Topics: Anticoagulants; Blood Specimen Collection; CD4 Lymphocyte Count; Culture Media; Didanosine; DNA, Viral; Drug Therapy, Combination; Enzyme-Linked Immunosorbent Assay; Evaluation Studies as Topic; False Negative Reactions; Gels; HIV Core Protein p24; HIV Infections; HIV-1; Humans; Polyesters; Polymerase Chain Reaction; Predictive Value of Tests; RNA, Viral; Severity of Illness Index; Specimen Handling; Viremia; Virus Cultivation; Zidovudine

We studied the influence of HIV p24 antigen immune complexing with anti-p24 antibodies on the assessment of their respective levels in HIV-positive sera. ELISAs were used to evaluate anti-p24 antibody levels and p24 antigenemia, with or without acid dissociation. Observations include the following: (1) p24 antigenemia usually coexisted with low anti-p24 levels; (2) the p24 antigen concentration inversely correlated with anti-p24 antibody levels; and (3) acid dissociation increased the percentage of p24 antigen-positive sera, mostly when anti-p24 was low. In contrast, (1) antigenemia and antibodies varied independently in antiretroviral-treated AIDS patients, undetectable p24 antigen coexisting then with low anti-p24; (2) after acid dissociation, antigen was still undetectable in 83% of sera with high antibody levels, and in 20% with low antibody levels; and (3) acid dissociation did not increase low anti-p24 levels. Whereas the first set of observations indicates that p24 antigen and anti-p24 antibodies can be engaged in immune complexes, the second set indicates that p24 antigen and antibodies were not inevitably linked in such complexes: they may actually be indicative of two distinct biological phenomena.

Topics: Antigen-Antibody Complex; Didanosine; HIV Antibodies; HIV Core Protein p24; HIV Infections; Humans; Prognosis; Viremia; Zidovudine

To determine if suppression of human immunodeficiency virus (HIV) replication during antiretroviral therapy correlates with clinical outcome, serial quantitative serum cultures and HIV p24 antigen measurements were made in patients with advanced HIV disease treated with didanosine. Twenty-one (78%) of 27 had viremia detected, and in 14 (67%) viral titer decreased by fivefold or more. Compared with those with no decrease, patients who had a decrease in titer were more likely to achieve a > or = 5% increase in body weight (8/12 vs. 0/7, P = .013) and had a significantly greater mean increase in body weight during treatment months 1-5. Occurrence of new AIDS-defining illnesses and survival were not significantly different between groups. Changes in p24 antigenemia did not correlate with any parameter of clinical outcome examined. Changing serum HIV titer is a marker of the virologic effect of didanosine therapy that correlates with the early clinical benefit as reflected by weight gain. However, correlation of this marker with long-term clinical benefit is uncertain.

Topics: Acquired Immunodeficiency Syndrome; Body Weight; Didanosine; HIV; HIV Core Protein p24; Humans; Survival Rate; Viremia

We established a method to estimate the amounts of HIV-1 particles in plasma from patients with HIV-1 infection by using polymerase chain reaction (PCR) following reverse transcription (RT) of viral RNA (RNA-PCR) and assessed the potential usefulness of this approach to monitor the changes of viral load in patients with AIDS or AIDS-related complex (ARC) receiving 2',3'-dideoxyinosine (ddI). Plasma samples were obtained from 77 patients with HIV-1 infection (49 AIDS/ARC and 28 asymptomatic seropositives). Following ultracentrifugation of plasma, RNA was extracted from the pelleted virus and subjected to RT and PCR. The number of HIV-1 virus particles in each sample was determined using known amounts of HIV-1 DNA as reference control for PCR. The current plasma RNA-PCR technique quantitatively detected HIV-1 particles in plasma from 76 of 77 (98.7%) HIV-1-infected individuals examined. The numbers of HIV-1 particles in plasma from patients with AIDS or ARC were markedly higher than those in plasma from asymptomatic seropositive individuals (p less than 0.0001). Higher levels of plasma HIV-1 particle numbers were detected in individuals with lower CD4+ T cell counts. Patients (n = 10) who received oral ddI at doses greater than or equal to 6.4 mg/kg/day for 8 to 14 weeks had a profound decrease in plasma HIV-1 particle numbers (p = 0.0051). Patients (n = 7) receiving ddI for 45 to 71 weeks also had a decrease (p = 0.018). It should be noted, however, that more research is required to evaluate the usefulness of this technique in assessing the disease status and monitoring the activity of antiretroviral therapy.

Topics: Base Sequence; Didanosine; DNA, Viral; HIV Core Protein p24; HIV Infections; HIV Seropositivity; HIV-1; Humans; Molecular Sequence Data; Polymerase Chain Reaction; RNA, Viral; Viremia