lewis-x-antigen and Acute-Disease

LeuTech is a sterile, lyophilised kit-packaged diagnostic system containing murine anti-CD15 IgM monoclonal antibody proprietary radiolabelled with technetium 99m ((99m) Tc) for infection imaging. After intravenous injection of LeuTech, diagnostic imaging can be obtained within 1h with conventional planar gamma camera techniques. LeuTech binds to neutrophils in vivo at the infection site. LeuTech is a fast (1h to obtain image), convenient (one-step injection), safe, effective (bright, clear images) and cost-effective diagnostic for existing and new nuclear imaging markets including chronic and acute indications such as appendicitis, ischaemic bowel, post-surgical infection and nosocomial infection. Palatin Technologies has successfully completed a Phase III trial with LeuTech in 203 patients at 10 sites in the USA for the detection of equivocal appendicitis. A BLA with the US FDA for LeuTech has been filed for the diagnosis of equivocal appendicitis. The US FDA has recommended LeuTech for approval for the diagnosis of appendicitis in patients with equivocal signs and symptoms. On 28 September 2000 Palatin received a 'complete review' letter from the FDA regarding the BLA for LeuTech. While, there were no further data requested on the safety and clinical efficacy of LeuTech, FDA requested some manufacturing, quality control and validation steps and data to be completed prior the approval of LeuTech. Palatin plans to finalise the amendments to BLA in the H2 of 2002. LeuTech is also being investigated in Phase II clinical trials for the diagnosis of osteomyelitis in 45 patients at four sites. Positive interim results from a Phase II clinical study conducted in 19 patients with diabetic foot ulcers and suspected osteomyelitis were announced at the Society of Nuclear Medicine Annual Meeting, Toronto, Canada, in June 2001. Imaging with LeuTech provided a diagnostic image within 1 hour compared with the 24 hours required to obtain an image using standard-of-care diagnostic, Indium oxide-labelled white blood cells. Walter Reed Army Medical Center is evaluating LeuTech for early detection of inhalation anthrax. LeuTech is planned to be evaluated for the detection of osteomyelitis secondary to joint replacements (such as hip replacement), postoperative abscesses, ulcerative colitis and other intra-abdominal infections (colitis, spleen or urinary tract). Palatin Technologies has exclusive rights to murine anti-CD15 IgM monoclonal antibody from The Wistar Institute o

Topics: Acute Disease; Antibodies, Monoclonal; Appendicitis; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Freeze Drying; Gamma Cameras; Humans; Inflammation; Lewis X Antigen; Radionuclide Imaging; Reagent Kits, Diagnostic; Technetium

Several studies have shown survival benefit by autologous stem cell transplantation in acute myeloid leukemia (AML) after purging of grafts. This has, however, not been confirmed in randomized studies due to high toxicity of purging modalities for normal progenitor/stem cells. In this study, we investigated whether positive selection for CD34+ and/or CD133+ cells, which results in high recovery of normal progenitor/stem cells, is applicable for purging AML grafts.. Positive selections of normal stem cells using CD34 and/or CD133 can be done if one or both markers are absent or have dim expression and remain so during the course of the disease. Marker expressions in newly diagnosed AML were measured with flow cytometry using a cutoff value for positivity of 1%. Stability of marker expression was studied by pairwise comparison of material at diagnosis and relapse. Leukemia associated phenotype expression was used to measure the efficacy of tumor cell reduction.. In newly diagnosed AML (n = 165), we found no CD34 and/or CD133 expression in 32% of the cases and dim expression in 20% of the cases. No increase in the percentage of CD34+ cells (n = 44) and CD133+ cells (n = 29) was found in corresponding relapses. Positive selection using grafts contaminated with AML blasts, showing either no or dim expression of CD34 or CD133, resulted in a 3 to 4 log tumor cell reduction (n = 11) with median 50% recovery of normal stem cells.. Purging by positive selection of CD34+ and/or CD133+ cells can safely, effectively, and reproducibly be applied in about 50% of AML cases.

Topics: AC133 Antigen; Acute Disease; Antigens, CD; Antigens, CD34; Bone Marrow Purging; Female; Glycoproteins; Hematopoietic Stem Cells; Humans; Leukemia, Myeloid; Leukocyte Common Antigens; Lewis X Antigen; Male; Peptides; Peripheral Blood Stem Cell Transplantation; Treatment Outcome

Sixteen patients with acute myeloid leukemia (AML) were treated with a continuous i.v. infusion of mAb PM-81, an IgM mAb directed against the cellular differentiation antigen CD15, which is expressed on leukemia cells of >95% of patients with AML. MAb PM-81, also referred to as MDX-11, is capable of activating human and rabbit complement and lysing CD15-positive AML cells. In this Phase I study, patients were treated with 0.5, 1.0, or 1.5 mg/kg MDX-11 delivered over a 24-h period followed by conventional chemotherapy. Transient decreases in circulating blast cells postinfusion (prior to chemotherapy) were observed at all doses. We were able to show MDX-11 binding to bone marrow blasts in those patients who achieved stable serum levels of MDX-11. Serum MDX-11 was detectable at the 1. 0- and 1.5-mg/kg doses. Doses of 0.5 and 1.0 mg/kg were generally well tolerated, with no toxicities greater than grade II (Eastern Cooperative Oncology Group) reported. However, two of five patients receiving the 1.5-mg/kg dose experienced grade IV toxicities that resolved with treatment (one of these patients completed the infusion). Common toxicities reported included fever, chills, and hypotension. Only one patient developed human antimouse antibodies at 4 weeks posttreatment. This study determined that 1.0 mg/kg is a biologically effective dose that can be administered safely with little toxicity. Based on these results, we are pursuing a Phase I/II study of MDX-11 infusion following chemotherapy for patients with relapsed AML.

Topics: Acute Disease; Adult; Aged; Antibodies, Monoclonal; Feasibility Studies; Female; HL-60 Cells; Humans; Immunoglobulin M; Leukemia, Myeloid; Leukocyte Count; Lewis X Antigen; Male; Middle Aged

To explore the possible molecular mechanism of Ikaros regulation on FUT4 expression by analyzing the correlation of the functional state of Ikaros with level of FUT4 expression, so as to provide the theoretical basis for personalized treatment in children with ALL.. The subtypes of Ikaros were identified by nested PCR and sequencing. The expression level of FUT4 was detected by quantitative PCR and analyzed by ΔΔCt method in the early stage of treatment, remission and relapse of ALL.. Ik1 and Ik2 were the main functional subtypes, and the dominant negative Ikaros was Ik6; the Ik6 was detected in 23 patients with ALL. It was found that 2.73% patients expressing Ik6 alone and 18.18% patients with heterozygous expression were detected. The expression of FUT4 in the newly diagnosed ALL was higher than that in the control group, and the functional Ikaros negatively correlated with the FUT4 expression(r=-0.6329).. Dominant negative Ikaros closely correlated with the relapse of acute lymphoblastic leukemia in children. The functional Ikaros negatively correlated with FUT4 expression. Ikaros inhibit the transcriptional activity of FUT4, that may be the molecular mechanism of Ikaros regulating the expression of FUT4.

Topics: Acute Disease; Child; Fucosyltransferases; Humans; Ikaros Transcription Factor; Lewis X Antigen; Precursor Cell Lymphoblastic Leukemia-Lymphoma; Protein Isoforms; Recurrence

Polysomy 8 is a rare abnormality, one that has been reported as associated with secondary evolution, monocytic differentiation, or poor prognosis in myeloid neoplasm. In contrast to tetrasomy 8, which is most commonly observed, pentasomy 8 is a minority component of polysomy 8. To date, only three cases of pentasomy 8 accompanied with 11q23 rearrangement have been reported. Reported here is a novel case of pentasomy 8 with partial tandem duplication of 11q23 in de novo acute myeloid leukemia. The findings contribute to understanding of the relation between the two abnormalities, which have their own individual leukemogenic potencies.

Topics: Acute Disease; Aged; Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Bone Marrow Cells; CD13 Antigens; Chromosome Aberrations; Chromosome Banding; Chromosomes, Human, Pair 11; Chromosomes, Human, Pair 8; Gene Duplication; HLA-DR Antigens; Humans; In Situ Hybridization, Fluorescence; Karyotyping; Leukemia, Myeloid; Lewis X Antigen; Male; Proto-Oncogene Proteins c-kit; Sialic Acid Binding Ig-like Lectin 3

We report the clinical and immunohistological features of two cases of chronic lymphocytic leukaemia (CLL) with Hodgkin's transformation. These cases occurred in a 70-year-old man with a three-year history of CLL and in a 76-year-old man with a few months history of CLL. Microscopic examination showed the presence of large tumor cells with the morphological and immunophenotypic features of classical Hodgkin and Reed-Sternberg (R-S) cells, in a background of otherwise typical B-CLL. The transformation of CLL into large B cell lymphoma (Richter's syndrome) is a well-documented phenomenon. Only rarely does CLL transform into Hodgkin's lymphoma, but this diagnosis is often easy and offers few differential diagnoses. The major points of interest lie in the pathogenetic relationship between CLL and Hodgkin's disease, and in the potential clinical implications of this peculiar condition. Literature on the subject indicates that identical IgH gene rearrangements in micromanipulated R-S and CLL cells have been identified in 7/12 cases. In these patients, the R-S and CLL cells belong to the same clonal population, suggesting a progression from the underlying CLL cells. This group appears to have a poor prognosis, identical to classical Richter's syndrome. In other cases, the R-S cells were often Epstein-Barr virus (EBV) positive and did not share the clonal rearrangements identified in CLL cells, suggesting that Hodgkin's disease in these patients could represent a second malignancy, EBV-related and favored by immunosuppression, associated with a better prognosis.

Topics: Acute Disease; Aged; Antibodies; Antigens, CD; CD79 Antigens; Genetic Variation; Hodgkin Disease; Humans; Leukemia, Lymphocytic, Chronic, B-Cell; Lewis X Antigen; Male; Neoplasm Staging; Reed-Sternberg Cells

This is a case report of a young patient who experienced an acute epidural compression of cauda equina revealing Stage IV Hodgkin's disease.. To draw attention to this rare presentation of Hodgkin's disease, and to assess the role of surgery in acute cauda equina compression in a context of a chemosensitive disease.. Lymphomatous tissue in Hodgkin's disease may involve the spine usually in the setting of advanced disease. Initial manifestation of Hodgkin's disease in the spine is rare. The management of this rare presentation may be conservative, but surgery provides the most rapid way of neurologic tissue decompression.. The case of a 14-year-old patient who experienced an acute epidural compression of cauda equina revealing Stage IV Hodgkin's disease is presented.. The patient complained of an increased lower back pain of 1-month duration before he developed lower limbs numbness, loss of perineal sensation, and urinary retention. Sagittal and axial T2-weighted magnetic resonance images of the lumbar spine revealed tumoral invasion of the epidural space compressing the cauda equina. Emergency surgical decompression was performed. In fine, Stage IV Hodgkin's disease revealed by acute epidural cauda equina compression was diagnosed. The patient recovered normal neurologic functions in a few days and then underwent chemotherapy and radiotherapy.. Although a rare situation, Hodgkin's disease may involve the spinal epidural space at presentation. The management is complex, but surgery provides the most rapid means of diagnosis and neurologic tissue decompression in severely affected patients.

Topics: Acute Disease; Adolescent; Cauda Equina; Hodgkin Disease; Humans; Immunohistochemistry; Ki-1 Antigen; Lewis X Antigen; Low Back Pain; Male; Nerve Compression Syndromes; Treatment Outcome

Appendicitis frequently presents in an atypical fashion leading to misdiagnosis or a delay in diagnosis. This is particularly true in early cases where the patient may be erroneously discharged from an emergency department and will invariably return with perforated appendicitis. The standard of care is hospital admission for observation or early operation. Adjunctive imaging tests have been used with mixed results in this equivocal patient population. The authors studied a promising new monoclonal antibody, 99mTc-labeled anti-CD 15 (LeuTech; Palatin Technologies, Inc., Princeton, NJ), which specifically targets neutrophils and may be used for imaging appendicitis. This prospective, multicenter, open-label study evaluated the diagnostic efficacy and clinical impact of LeuTech scintigraphy for detecting appendicitis in patients with an equivocal presentation.. A total of 200 patients (121 females, 79 males; age range 5-86 years; mean age 30.5 +/- 16.5 years) completed the study. Management plan was formulated before and reassessed following LeuTech imaging to determine impact on management. Following intravenous injection of LeuTech, the abdomen was imaged with a standard gamma camera for 30 to 90 minutes.. Fifty-nine patients had a histopathologic diagnosis of acute appendicitis. LeuTech identified 53 of 59 patients with appendicitis (90% sensitivity) and was negative in 122 of 141 patients without appendicitis (87% specificity). Accuracy, positive predictive value, and negative predictive value were 88%, 74%, and 95%, respectively. Diagnostic efficacy was unchanged in a subgroup of 48 pediatric patients (5-17 years). Diagnostic images for appendicitis were achieved within 8 minutes postinjection in 50% of patients and within 47 minutes in 90% of patients. Significant shifts in patient management decisions were evident following LeuTech results. LeuTech was well tolerated with no serious adverse events reported.. LeuTech is a convenient, safe, rapid, and sensitive imaging test for diagnosis of appendicitis and favorably impacts patient management in adult and pediatric patients with equivocal signs and symptoms.

Topics: Acute Disease; Adolescent; Adult; Aged; Aged, 80 and over; Antibodies, Monoclonal; Appendicitis; Child; Female; Humans; Lewis X Antigen; Male; Middle Aged; Predictive Value of Tests; Prospective Studies; Radionuclide Imaging; Technetium

We evaluated 99mTc-labeled anti-CD15 immunoglobulin M monoclonal antibody (LeuTech) for diagnosing acute appendicitis in patients with an equivocal clinical presentation. LeuTech avidly binds to circulating and sequestered human polymorphonuclear neutrophils in vivo, eliminating in vitro cell labeling and blood handling.. We studied 49 patients to evaluate the safety and efficacy of LeuTech imaging. 99mTc-labeled LeuTech was prepared on site using a lyophilized kit, 99mTc-labeled pertechnetate, and 2 different incubation techniques, 1 at room temperature and the other at 37 degrees C. The abdomen was serially imaged for up to 3 h after the intravenous administration of 370-740 MBq 99mTc-labeled LeuTech. Scans were read as positive or negative for acute appendicitis or other intraabdominal infection. The institutional diagnosis was established by surgery, other diagnostic studies, or 1-mo clinical follow-up.. Scans were positive for appendicitis in all 26 patients with appendicitis, for a sensitivity of 100%, and negative for appendicitis in 19 of 23 patients without appendicitis, for a specificity of 83%. Accuracy, positive predictive value, and negative predictive value were 92%, 87%, and 100%, respectively. Results were not different between the LeuTech preparations. The rate of laparotomies with negative findings in patients who underwent surgery was 10%. The average time from injection to LeuTech visualization in the appendix for cases positive for appendicitis was 9 min. No serious adverse reactions occurred.. LeuTech imaging is safe, rapid, and sensitive for diagnosis of appendicitis in equivocal cases. The potential advantages of LeuTech over currently available radiopharmaceuticals for infection imaging are ease of preparation, absence of blood handling, excellent image quality, no requirement for SPECT, and rapid diagnostic uptake.

Topics: Acute Disease; Adult; Animals; Antibodies, Monoclonal; Appendicitis; Female; Humans; Isotope Labeling; Lewis X Antigen; Male; Mice; Neutrophils; Radioimmunodetection; Radiopharmaceuticals; Sensitivity and Specificity; Sodium Pertechnetate Tc 99m

Topics: Acute Disease; Animals; Antibodies, Monoclonal; Appendicitis; Emergency Service, Hospital; Humans; Lewis X Antigen; Mice; Radioimmunodetection; Radiopharmaceuticals; Sodium Pertechnetate Tc 99m

We evaluated Tc-99m-labeled anti-CD15 immunoglobulin M monoclonal antibody (LeuTech) for scintigraphic detection of acute appendicitis in patients with an equivocal clinical presentation. LeuTech avidly binds to circulating and sequestered human polymorphonuclear neutrophils in vivo eliminating the need for in vitro cell labeling and the risks of blood handling. We studied 99 patients to evaluate the safety and efficacy of LeuTech imaging. Serial dynamic and static planar images were acquired for up to 3 hours after the intravenous administration of 10 to 20 mCi of Tc-99m LeuTech. Scans were read as positive or negative for acute appendicitis or other intra-abdominal infection. The institutional diagnosis was established by surgery and histopathology of the appendix, results of other diagnostic studies, or 2-week clinical follow-up. Scans were positive for appendicitis in 39 of 40 patients with appendicitis at surgery (sensitivity 98%) and negative for appendicitis in 49 of 58 patients without appendicitis (specificity 84%). One was lost to follow-up. Accuracy, positive predictive value, and negative predictive value were 90, 81, and 98 per cent respectively. In patients with appendicitis and positive scans more than 50 per cent of the images were positive at 4 minutes, and all were positive by 1 hour. Mean time of first positive image was 15 minutes. There were no serious adverse reactions. We conclude that LeuTech imaging is a highly sensitive test for detection of appendicitis in equivocal cases. There are advantages of this agent over the other currently used radiotracers in terms of convenience and time to diagnosis particularly the rapidity with which acute appendicitis will be seen on the images.

Topics: Abdomen; Abdominal Pain; Acute Disease; Antibodies, Monoclonal; Appendectomy; Appendicitis; Follow-Up Studies; Humans; Immunoglobulin M; Injections, Intravenous; Lewis X Antigen; Neutrophils; Predictive Value of Tests; Radioimmunodetection; Radiopharmaceuticals; Safety; Sensitivity and Specificity; Technetium Tc 99m Exametazime

Blockage in myeloid differentiation characterizes acute myeloid leukemia (AML); the stage of the blockage defines distinct AML subtypes (AML1/2 to AML5). Differentiation therapy in AML has recently raised interest because the survival of AML3 patients has been greatly improved using the differentiating agent retinoic acid. However, this molecule is ineffective in other AML subtypes. The CD44 surface antigen, on leukemic blasts from most AML patients, is involved in myeloid differentiation. Here, we report that ligation of CD44 with specific anti-CD44 monoclonal antibodies or with hyaluronan, its natural ligand, can reverse myeloid differentiation blockage in AML1/2 to AML5 subtypes. The differentiation of AML blasts was evidenced by the ability to produce oxidative bursts, the expression of lineage antigens and cytological modifications, all specific to normal differentiated myeloid cells. These results indicate new possibilities for the development of CD44-targeted differentiation therapy in the AML1/2 to AML5 subtypes.

Topics: Acute Disease; Antibodies, Monoclonal; Bone Marrow; Cell Differentiation; Dose-Response Relationship, Drug; Granulocyte Colony-Stimulating Factor; Granulocytes; Humans; Hyaluronan Receptors; Hyaluronic Acid; Leukemia, Myeloid; Lewis X Antigen; Lipopolysaccharide Receptors; Macrophage Colony-Stimulating Factor; Monocytes; Neoplasm Proteins; Oncogene Proteins, Fusion; Respiratory Burst; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

We have investigated the differentiation potential of blast cells in a case of acute myeloid leukemia which comprised a majority CD34- population and a minor (2%) CD34+ fraction. Blasts were cultured for 2 weeks in a combination of cytokines--c-Kit ligand, interleukin 3 and granulocyte macrophage colony-stimulating factor (SIGm mix)--together with all-trans retinoic acid or 1alpha ,25-dihydroxy vitamin D3. Maturation of blasts was assessed by morphology on Romanowsky-stained slides, changes in surface CD markers and clonogenic culture. After 7 days of culture of unseparated blasts in SIGm, most maturation was monocytic, but with retinoic acid 63% of blasts had matured into granulocytes. Vitamin D3 enhanced monocytic differentiation, with 60% of cells becoming monocytic. The percentage of CD14 and CD15 positive cells decreased over 7 days in SIGm (from 62% to 17% and from 76% to 39% for CD14 and CD15, respectively). CD14+ cell numbers were maintained, or recovered, in cultures supplemented with vitamin D3 (59% at day 7), and CD15+ cell numbers, too, remained unchanged in the presence of retinoic acid (67%) or vitamin D3 (66%). Aberrant markers CD7 and CD56 declined under any conditions. When separated, both the CD34- and CD34+ fractions showed similar changes in morphology and surface maturation markers, suggesting that these two populations may be closely related. However, only a few CD34+ cells expressed the aberrant markers present on the majority blast population. The CD34- population declined in culture while the CD34+ fraction rapidly expanded. This probably reflects the difference in progenitor content; high numbers of colony-forming cells were concentrated in the CD34+ subpopulation. We conclude that both CD34- and CD34+ populations can differentiate but only the CD34+ fraction proliferates. Primitive clonogenic CD34+ cells from this patient may generate occasional aberrant CD34+ blasts which could then differentiate into the accumulating aberrant CD34- blast population.

Topics: Acute Disease; Aged; Antigens, CD34; Antigens, CD7; CD56 Antigen; Cell Division; Clone Cells; Colony-Forming Units Assay; Hematopoietic Stem Cells; Humans; Leukemia, Myeloid; Leukocyte Common Antigens; Leukocyte Count; Leukocytes, Mononuclear; Lewis X Antigen; Lipopolysaccharide Receptors; Tumor Cells, Cultured

The OMA-AML-1, acute myelogenous leukemia cell line is unique in that it spontaneously maintains both a CD34+ precursor cell compartment and a CD15+ differentiating cell compartment in vitro. A third transitional cell type with co-expression of CD34 and CD15 can also be identified in in vitro cultures. The cell line shows dynamic fluctuations in the relative sizes of these three cell compartments in suspension culture. In contrast, OMA-AML-1 fails to show phenotypic or morphologic evidence of differentiation when grown subcutaneously in immunodeficient mice. OMA-AML-1 responds to a number of hematopoietic cytokines. Delineation of cytokine responses on FACS isolated populations of CD34+ versus CD15+ cells demonstrated that proliferative responses occurred primarily at the level of the precursor cell (CD34+) while the production of endstage eosinophils occurred within the CD15+ compartment. OMA-AML-1 mimics a number of features of normal hematopoiesis and is proving to be a useful in vitro model for the study of hematopoietic differentiation.

Topics: Acute Disease; Animals; Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Cell Differentiation; Cell Division; Cell Line; Cytokines; Hematopoietic Stem Cells; Humans; Immunophenotyping; Leukemia, Myeloid; Lewis X Antigen; Mice; Mice, SCID; Models, Biological; Transplantation, Heterologous; Tumor Cells, Cultured

In the present study we investigated the membrane expression of selectin ligands (CD15/Le(x), CDw65/VIM2, CD15s/sLe(x), beta 2 integrins (CD11a/LFA-1, CD11b/Mac-1) and CD45 phosphatase isoforms (CD45RA, CD45O) on leukaemic cells from 28 patients with acute myeloid malignancies cultured with and without all-trans retinoic acid (ATRA). Within each adhesion system. ATRA was able to differentially regulate distinct molecules. Furthermore, it was able to exert effects specific for acute promyelocytic leukaemia (APL) blast cells, as well as to induce a series of non-cytotype-restricted phenotypic changes. An impressive feature of ATRA induction was a simultaneous increase in the expression of CD15, CDw65 and CD11b on leukaemic promyelocytes. The sialylated antigen CD15s, however, showed results independent from the other two carbohydrates (CD15 and CDw65), suggesting a differential enzymatic regulation within the selectin ligands system. In spite of the well-recognized expression of CD11a throughout all stages of normal myeloid differentiation, APL blast cells were found to virtually lack LFA-1 expression. Moreover, ATRA was unable to promote an up-regulation of this antigen in APL, while inducing a frequent down-modulation in non-APL cases constitutively expressing this antigen. In APL cases ATRA generated an asynchronous phenotype (CD15+, CDw65+, CD11b+, CD11a-), undetectable on normally maturing myeloid cells, but consistent with the concept that incomplete differentiation, in terms of surface molecule expression, can be sufficient to obtain therapeutic results.

Topics: Acute Disease; Antigens, CD; CD11 Antigens; Cell Adhesion Molecules; Cell Differentiation; Humans; Leukemia, Myeloid; Lewis X Antigen; Neoplasm Proteins; Tretinoin

A cyclophosphamide congener, 4-hydroperoxycyclophosphamide (4HC), has been used to purge bone marrow (BM) of residual leukemia cells ex vivo for use in support of high-dose chemotherapy for patients with acute myeloid leukemia (AML) undergoing autologous BM transplantation (ABMT). The efficacy and toxicity of 4HC are dose-related. The maximally tolerated concentration, 60-100 micrograms/ml, is toxic to tumor cells but also to normal committed hematopoietic progenitor cells. The anti-CD15 monoclonal antibody (mAb) PM-81 has also been employed for purging BM in patients with AML. In some patients, all tumor cells may not be lysed due to antigenic heterogeneity. Because the two agents used individually are associated with potential limitations in terms of toxicity to normal cells and efficacy of tumor cell purging, using these agents together might have advantages. In fact, in this study the use of these two agents together in subtherapeutic concentration ranges as single agents revealed killing of cells from the HL60 and NB4 promyelocytic leukemia cell lines in addition to cells from patients with AML while sparing normal progenitor cells. Surprisingly, not only did the combination enhance killing of tumor cells, but the order of addition of the two agents was important in maximizing toxicity to tumor cells. Adding mAb+complement (C') first or simultaneously to 4HC was less effective than adding 4HC first followed by mAb + C'. This combination regimen was toxic to HL60 and NB4 leukemia cells that may not be killed by the mAb alone due to antigen-negative tumor cells or by low concentrations of 4HC.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Acute Disease; Antibodies, Monoclonal; Bone Marrow Purging; Combined Modality Therapy; Cyclophosphamide; Cytotoxicity, Immunologic; Hematopoietic Stem Cells; Humans; Leukemia; Leukemia, Myeloid; Leukocytes, Mononuclear; Lewis X Antigen; Tumor Cells, Cultured

Surface markers were studied at first relapse in 66 cases of acute myeloid leukaemia (AML), using a panel of five monoclonal antibodies directed to CD13, CD14, CD15, CD33 and CD34 antigens. At time of relapse, there was increased expression of CD33 (P = 0.002) and CD34 (P = 0.0001), and decreased expression of CD13 (P = 0.004) and CD15 (P = 0.0001) antigens by comparison to initial diagnosis. There was no strict correlation with the FAB classification. However, CD13 and CD33 expression changes preferentially affected granulocytic leukaemias. At relapse, CD14 and CD34 were significantly more expressed in monocytic than in granulocytic AML (P = 0.01 and 0.003 respectively). In a multivariate analysis, CD34 expression was associated with a low CR rate (P = 0.001) and short survival (P = 0.05), whereas CD15 expression was associated with long survival (P = 0.0004). These results suggest that AML tends to relapse with a less differentiated phenotype than observed at diagnosis and that AML with less differentiated phenotype is of poor prognosis after first relapse, as also observed at diagnosis.

Topics: Acute Disease; Adult; Aged; Antibodies, Monoclonal; Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Antigens, Surface; CD13 Antigens; Female; Fluorescent Antibody Technique; Humans; Leukemia, Myeloid; Lewis X Antigen; Lipopolysaccharide Receptors; Male; Middle Aged; Multivariate Analysis; Phenotype; Prognosis; Recurrence; Sialic Acid Binding Ig-like Lectin 3

To establish the basis for the reduced expression of the X determinant on leukemic blasts and the changes in antigenic expression that occur during myeloid maturation, the presence on myeloid cells of X and related structures was examined in conjunction with studies on the activities of the glycosyltransferases involved in their biosynthesis. Expression of X and sialyl-X was weak on blasts in comparison with neutrophils despite the presence of the requisite precursor structures. Much higher levels of 3-fucosyltransferase activity were found in blasts than in neutrophils when nonsialylated substrates were used, but, whereas the enzyme in neutrophils reacted equally well with 3'-sialylated and nonsialylated acceptors, the enzyme in blasts showed a marked preference for nonsialylated substrates. 6'-Sialyltransferase activity was strong in blasts but was not detectable in neutrophils, whereas a much lower level of 3'-sialyltransferase activity was present in both blasts and neutrophils. Dimethyl sulfoxide-induced maturation of HL60 cells was associated with (1) a decrease in both 6'-sialyltransferase and 3-fucosyltransferase activities, (2) a change in the substrate specificity of 3-fucosyltransferase towards that found in mature cells, and (3) increased cell surface expression of sialyl-X. These results suggest that the reduced expression of X in myeloblasts is related to the presence of the strong 6'-sialyltransferase, which uses the precursor substrate at the expense of the 3-fucosyltransferase and prevents the synthesis of X and sialyl-X. The developmental regulation of the levels of 3'- and 6'-sialyltransferases, and the level and specificity of the 3-fucosyltransferases, therefore controls the expression of X and its degree of sialylation.

Topics: Acute Disease; Antigens, CD; beta-D-Galactoside alpha 2-6-Sialyltransferase; beta-Galactoside alpha-2,3-Sialyltransferase; Cell Differentiation; Dimethyl Sulfoxide; Enzyme Induction; Humans; Leukemia, Myeloid; Lewis X Antigen; Neutrophils; Sialyltransferases; Tumor Cells, Cultured

Although monoclonal antibodies (MoAbs) to CD15, especially PM-81, react with leukemic blasts from the majority of patients with acute myeloid leukemia (AML), a small subset of patients have cells that are CD15 negative or dim. We determined previously that neuraminidase will increase the reactivity of PM-81 with AML blasts, as well as blasts from many patients with acute lymphoblastic leukemia (ALL). In this report, we describe the laboratory results and clinical course of the first patient with AML whose harvested bone marrow was treated with neuraminidase prior to MoAbs and complement treatment. Neuraminidase increased the percentage of the patient's leukemia cells that reacted with PM-81 from 18% to 90% and more than doubled the percentage of AML blasts that were lysed by PM-81 and complement. The patient suffered no acute toxicity, engrafted rapidly, and was transfusion independent by day 21 post-ABMT. This report demonstrates the probable safety and efficacy of pretreatment of bone marrow with neuraminidase, and increases the number of patients with AML or ALL who may benefit from ABMT using marrow purging with MoAb to CD15.

Topics: Acute Disease; Antibodies, Monoclonal; Antigens, Differentiation; Bone Marrow; Bone Marrow Transplantation; Complement System Proteins; Humans; Leukemia, Myeloid; Lewis X Antigen; Male; Middle Aged; Neuraminidase; Transplantation, Autologous

The phenotypic marker profile of a case of acute leukemia is described; its immunophenotype is unique in that the blast cells were initially negative for a wide panel of monoclonal antibodies (McAbs) to surface and intracytoplasmic antigens and for the nuclear enzyme terminal deoxynucleotidyl transferase. Morphological and cytochemical examination suggested an acute myeloid leukemia (AML), but the cells were unreactive with anti-myeloid McAbs. Treatment with the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) induced the cells to differentiate morphologically to macrophage-like cells and led to the expression of surface antigens that could be detected by antimyeloid McAbs. It is not clear whether these cells represent a rare subclass of leukemic cells that are void of any characteristic surface markers but have the potential to differentiate along the myeloid axis, or whether the antigens were masked by an unknown process.

Topics: Acute Disease; Aged; Antibodies, Monoclonal; Antigens, Neoplasm; Antigens, Surface; Blast Crisis; Cells, Cultured; Flow Cytometry; Fluorescent Antibody Technique; Humans; Hybridization, Genetic; Leukemia; Leukemia, Myeloid, Acute; Lewis X Antigen; Lymphocytes; Male; Neuraminidase; Phenotype; Tetradecanoylphorbol Acetate

Several mouse monoclonal antibodies (MoAbs) considered specific for the myeloid lineage recognize the same carbohydrate structure (3-fucosyl-N-acetyl-lactosamine) which is similar to the murine antigen SSEA-I. We have investigated the expression of this antigen with six different well-characterized murine IgM MoAbs on normal, leukaemic, and cultured cells by immunofluorescence and immunoelectron microscope cytochemistry. The cells were studied before and after neuraminidase treatment since epitopes recognized by these MoAbs may be masked by sialic acid. Among the recognizable normal marrow or blood cells, all these MoAbs specifically labelled the granulocytic lineage from the promyelocyte to the polymorph. After neuraminidase treatment, monocytes became labelled. All the other lineages remained unstained. Several cell lines were studied. Six of eight lymphoblastoid cell lines were stained by these MoABs; reactivity was increased by neuraminidase. One Burkitt cell line and two T cell lines were also found to be positive. These antibodies were tested on leukaemic cells. In acute non-lymphocytic leukaemia they usually labelled promyelocytes, more mature granulocytic and monocytic precursors but did not label myeloblasts; after neuraminidase treatment, these myeloblasts became stained. No labelling was observed on leukaemic proerythroblasts and promegakaryoblast before and after neuraminidase treatment except in one case of promegakaryoblastic leukaemia in which the SSEA-I antigen and platelet peroxidase were expressed in the same cell. In addition, six cases of common acute lymphoblastic leukaemia were studied; the blasts became positive after desialylation. Two examples of T cell acute leukaemia were essentially negative. We conclude, therefore, that the reactivity of haemopoietic cells with these MoAbs alone does not represent a criterion sufficient to sustain their myeloid origin since the SSEA-I antigen may be expressed at the surface of all cell lineages in the early phases of haemopoietic differentiation.

Topics: Acute Disease; Animals; Antibodies, Monoclonal; Antigens, Neoplasm; Antigens, Surface; Blood Cells; Cell Line; Epitopes; Glycolipids; Hematopoietic Stem Cells; Humans; Leukemia; Lewis X Antigen; Mice; Microscopy, Electron; Neuraminidase; Oligosaccharides