abacavir and Inflammation

D-dimer concentrations in people living with HIV (PLHIV) on combination antiretroviral therapy (cART) are increased and have been linked to mortality. D-dimer is a biomarker of in vivo coagulation. In contrast to reports on D-dimer, data on coagulation capacity in PLHIV are conflicting. In this study, we assessed the effect of cART and inflammation on coagulation capacity.. We explored coagulation capacity using calibrated thrombin generation (TG) and linked this to persistent inflammation and cART in a cross-sectional study including PLHIV with viral suppression and uninfected controls.. We used multivariate analyses to identify independent factors influencing in vivo coagulation (D-dimer) and ex vivo coagulation capacity (TG).. Among 208 PLHIV, 94 (45%) were on an abacavir-containing regimen. D-dimer levels (219.1 vs 170.5 ng/mL, P = 0.001) and inflammatory makers (sCD14, sCD163, and high-sensitive C-reactive protein) were increased in PLHIV compared with those in controls (n = 56). PLHIV experienced lower TG (reflected by endogenous thrombin potential [ETP]) when compared with controls, after correction for age, sex, and antiretroviral therapy. Abacavir use was independently associated with increased ETP. Prothrombin concentrations were strongly associated with ETP and lower in PLHIV on a non-abacavir-containing regimen compared with those in controls, suggesting consumption as a possible mechanism for HIV-associated reduction in TG. D-dimer concentrations were associated with inflammation, but not TG.. Abacavir use was associated with increased TG and could serve as an additional factor in the reported increase in thrombotic events during abacavir use. Increased exposure to triggers that propagate coagulation, such as inflammation, likely underlie increased D-dimer concentrations found in most PLHIV.

Topics: Adult; Anti-HIV Agents; Biomarkers; Blood Coagulation; C-Reactive Protein; Cross-Sectional Studies; Dideoxynucleosides; Female; Fibrin Fibrinogen Degradation Products; HIV Infections; Humans; Inflammation; Lipopolysaccharide Receptors; Male; Middle Aged; Plasma; Prospective Studies; Thrombomodulin

Triple-drug regimens are the gold standard for HIV therapy. Nucleos(t)ide reverse transcriptase inhibitors (NRTIs) reducing regimens are used to decrease drugs toxicity, exposure and costs. Aim of our study was to evaluate trends of biochemical and inflammatory indices in patients switching to dual therapy (DT).. We included patients that a) switched to a DT from 2007 to 2015 from a tenofovir/abacavir-based triple regimen b) previously maintained a triple and c) subsequently a dual regimen for 12 months with virological suppression. We retrieved data measured at 5 points (at the switch, 6 and 12 months before and after switch). We used platelet-to-lymphocyte ratio (PLR), neutrophil-to-lymphocyte ratio (NLR) and CD4/CD8 ratio as inflammatory indices. We assessed temporal trends of viro-immunological, biochemical and inflammatory parameters.. Overall, 364 and 65 patients switched from a tenofovir- and an abacavir-triple regimen, respectively. In the tenofovir-reducing group, creatinine clearance and lipids raised after the switch. There was a significant increase in both CD4+ cells and CD4/CD8. CD8+ cells rose after the switch, while opposite trend was found for PLR. In the abacavir-reducing group total lipids showed a decrease during the first 6 months after the switch and then stabilized. An increase of CD4+ and a decrease of CD8+ cells was observed during the study period, although not statistically significant. While CD4/CD8 remained stable after simplification, PLR decreased significantly after 6 months, then returning to baseline. CD8+ cells increased in the tenofovir-reducing group despite a viro-immunological response. Intriguingly, PLR decreased, maintaining this trend for 12 and 6 months after tenofovir and abacavir interruption respectively.. Increased PLR has been linked to hypercholesterolemia and metabolic-syndrome, while high CD8+ cells count to increased risk of non-AIDS-related events regardless of CD4 T-cell recovery and to virological failure. Whether these findings may have clinical implications, and which role DT plays on the immune system and on inflammation should be further investigated.

Topics: Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Atazanavir Sulfate; CD4-CD8 Ratio; Cohort Studies; Darunavir; Dideoxynucleosides; Female; HIV Infections; Humans; Inflammation; Italy; Male; Middle Aged; Retrospective Studies; Reverse Transcriptase Inhibitors; Tenofovir; Treatment Outcome

The association between abacavir (ABC) and cardiovascular disease (CVD) risk in HIV-infected individuals is unclear. Putative mechanisms for an effect of ABC on CVD risk including endothelial dysfunction have been proposed; however, a biological mechanism has not been established.. This was a cross-sectional study of HIV-infected subjects with HIV RNA levels <400 copies/ml, who were randomly assigned to ABC or tenofovir (TDF) as initial therapy during a prior clinical trial. A small cohort of subjects on zidovudine (AZT; not randomly assigned) were studied to explore long-term exposure to this agent. All underwent brachial artery ultrasound for flow-mediated dilation (FMD), and D-dimer, high-sensitivity C-reactive protein (hsCRP), interleukin-6 (IL-6) and fasting lipids were measured. Between-arm differences were evaluated by multivariable linear or logistic regression modelling.. There were 148 subjects (46 on ABC, 72 on TDF and 30 on AZT). Demographic characteristics were balanced across the groups except, as expected, AZT-treated participants were older, had higher CD4(+) T-cell counts, and longer antiretroviral therapy duration. After adjusting for age, brachial artery diameter, and treatment duration, FMD was similar in those on ABC (3.9%) and TDF (5.4%; P=0.181). FMD was higher in those on AZT (6.1%; P<0.005). Levels of IL-6, hsCRP and detectable D-dimer were similar between groups.. Among individuals assigned to ABC or TDF in randomized clinical trials there were no significant differences in FMD or markers of inflammation and coagulation. Whether ABC contributes to risk of CVD remains unclear, but our results suggest that endothelial dysfunction, heightened inflammation, and altered coagulation are unlikely to be mechanisms by which the drug could increase CVD risk above that seen with TDF.

Topics: Adenine; Adult; Anti-HIV Agents; Biomarkers; Blood Coagulation; Cardiovascular Diseases; Dideoxynucleosides; Endothelium, Vascular; Female; HIV Infections; Humans; Inflammation; Male; Middle Aged; Organophosphonates; Risk Factors; Tenofovir; Zidovudine

Abacavir has been associated with myocardial infarction in several studies. This may be related to inflammation and endothelial cell activation. We compared changes in inflammation and endothelial activation markers between antiretroviral-naive adults initiating zidovudine, lamivudine, abacavir, and nonnucleoside reverse transcriptase inhibitor (NNRTI) or this regimen without abacavir. Changes in soluble tumor necrosis factor receptors-I, -II (sTNFR-I, -II), high sensitivity C-reactive protein, and soluble vascular cell adhesion molecule-1 (sVCAM-1) from baseline (pre-ART) to a second time point about 24 weeks after initiating antiretroviral therapy (ART) were compared between groups using multivariable linear regression. A total of 37 met eligibility criteria; 12 received abacavir. The median (interquartile range) age was 37 years (27-45). Most were men (32/37), African-American (15/37), or white (15/37). The median nadir CD4(+) and baseline HIV-1 RNA were 230 cells/mm(3) (180-301) and 82,642 copies/ml (34,400-204,703). In all, 15/30 smoked, 7/37 had hypertension, 1/37 had diabetes, and 1/37 had hyperlipidemia. None had coronary or renal disease. Changes in CD4(+) and HIV-1 RNA level and timing of stored samples with regard to ART initiation were not different between groups. In univariable analysis, log transformed percent change in sTNFR-I (p=0.05) and -II (p=0.04) showed significant between-group differences and trended toward significance for sVCAM-1 (p=0.08). These markers decreased less in the abacavir group. After adjustment for confounders, significantly less decrease for sTNFR-II and sVCAM-1 was seen for those receiving the abacavir-containing regimen. When taken with an NNRTI, abacavir induced a smaller decrease in inflammation biomarkers in this cohort, suggesting a possible proinflammatory effect of this nucleoside analogue.

Topics: Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Cohort Studies; Dideoxynucleosides; Endothelial Cells; Female; HIV Infections; Humans; Inflammation; Male; Middle Aged; Retrospective Studies

The use of abacavir and didanosine in HAART has been associated with an increased risk of myocardial infarction in HIV-infected patients. The aim of this study was to address the development of endothelial dysfunction in cultivated coronary artery endothelial cells (HCAECs) in response to abacavir, didanosine and tenofovir. We examined the impact of these drugs on the expression levels of the proinflammatory, oxidative stress and apoptosis regulating genes in HCAECs.. We tested gene and protein expression changes in HCAECs in response to abacavir, didanosine and tenofovir using quantitative real-time reverse transciptase PCR, FACS and ELISA. The assessed genes/proteins included the proinflammatory molecules VCAM-1, ICAM-1, MCP-1, RANTES and IL-6. In addition, we assessed the gene expression of the intracellular reactive oxygen producing NADPH oxidase subunit gp91(PHOX) and the apoptosis regulating molecules Bcl-2 and BAD.. Exposure of HCAECs to abacavir, didanosine and tenofovir resulted in no statistically significant changes in any of the tested genes/proteins at any time point or at any concentration.. We found no evidence that abacavir, didanosine or tenofovir had direct in vitro effects on coronary endothelial cell gene transcription and protein expression of the selected mediators. If abacavir or didanosine increase cardiovascular risk, it is likely not through the direct endothelial activation pathways tested in these experiments. However, further studies are needed to completely exclude the toxicity of abacavir or didanosine on endothelial cells.

Topics: Adenine; Anti-HIV Agents; Apoptosis; Cardiovascular Diseases; Cell Adhesion Molecules; Coronary Vessels; Cytokines; Didanosine; Dideoxynucleosides; Endothelial Cells; Gene Expression; Gene Expression Profiling; HIV Infections; HIV-1; Humans; Inflammation; NADPH Oxidases; Organophosphonates; Oxidative Stress; Primary Cell Culture; Proto-Oncogene Proteins; Tenofovir

To assess associations between abacavir (ABC) use and systemic inflammation.. Nested case-control study.. The Multicenter AIDS Cohort Study (MACS) and Women's Interagency HIV Study (WIHS) cohort participants who initiated ABC were matched, using propensity score methods, to ABC-unexposed persons. Levels of high-sensitivity C-reactive protein (hsCRP) (microg/ml), interleukin-6 (IL-6) (pg/ml), and D-dimer (microg/ml) were measured from pre-HAART and on-HAART plasma. Random-effects models compared markers by ABC exposure and by changes from pre-HAART levels.. Biomarkers were measured in N = 508 matched pairs (328 women; 180 men). Pre-HAART levels did not differ by exposure group except that hsCRP levels were higher among WIHS women who subsequently used ABC (P = 0.04). Regardless of ABC use, mean hsCRP increases and D-dimer reductions were seen when comparing pre-HAART to on-HAART levels, in the overall group (28 and -27%), for MACS men (28 and -31%) and for WIHS women [29 and -24%, P < 0.01 for all]; IL-6 levels declined in MACS men (P = 0.02). No adjusted biomarker level differences existed by ABC exposure at the on-HAART visit. HIV RNA reductions correlated with D-dimer (r = 0.14, P < 0.01) and IL-6 (r = 0.12, P < 0.01) reductions. Associations between ABC use and mean biomarker levels were modified by pre-HAART antiretroviral therapy experience. Renal dysfunction was equally likely among non-ABC and ABC recipients.. ABC use was not associated with plasma elevations in hsCRP, IL-6, and D-dimer. Mechanisms other than increased systemic inflammation may account for ABC's reported association with increased cardiovascular disease. HAART-associated reductions in D-dimer and IL-6 were apparent regardless of ABC use and were correlated with HIV RNA reductions.

Topics: Adult; Anti-HIV Agents; Antiretroviral Therapy, Highly Active; Biomarkers; C-Reactive Protein; Case-Control Studies; Dideoxynucleosides; Female; Fibrin Fibrinogen Degradation Products; HIV Infections; HIV-1; Humans; Inflammation; Inflammation Mediators; Interleukin-6; Male; Middle Aged; Reverse Transcriptase Inhibitors; RNA, Viral