lewis-x-antigen and Leukemia--Promyelocytic--Acute

Although the occurrence of thrombosis in acute promyelocytic leukemia (APL) has been reported during retinoic acid treatment, no studies carried out in large clinical cohorts have specifically addressed this issue. We analyzed 124 APL patients treated with the all-trans retinoic acid and idarubicin protocol and compared clinico-biologic characteristics of 11 patients who developed thrombosis with those of 113 patients who had no thrombosis. In seven patients, the events were recorded during induction, whereas in four patients deep vein thrombosis occurred in the post-induction phase. Comparison of clinico-biological characteristics of patients with and without thrombosis revealed in the former group higher median white blood cell (WBC) count (17 x 10(9)/l, range 1.2-56, P=0.002), prevalence of the bcr3 transcript type (72 vs 48%, P=0.01), of FLT3-ITD (64 vs 28%, P=0.02), CD2 (P=0.0001) and CD15 (P=0.01) expression. No correlation was found with sex, age, French-American-British subtype, all-trans-retinoic acid syndrome or with thrombophilic state that was investigated in 5/11 patients. Our findings suggest that, in APL patients consistent biologic features of leukemia cells may predict increased risk of developing thrombosis.

Topics: Adult; Aged; Antibiotics, Antineoplastic; Antineoplastic Agents; CD2 Antigens; Female; fms-Like Tyrosine Kinase 3; Humans; Idarubicin; Leukemia, Promyelocytic, Acute; Leukocyte Count; Lewis X Antigen; Male; Middle Aged; Mutation; Predictive Value of Tests; Risk Factors; Tandem Repeat Sequences; Thrombosis; Tretinoin

Limited information is available on the relationship between expression of some additional aberrant phenotypic features and outcome of acute promyelocytic leukemia (APL) patients. Here, we set out to assess the frequency of CD15 and CD56 expression, and their prognostic value in a large series of APL patients. One hundred and fourteen adult patients consecutively diagnosed with PML/RARα-positive APL and homogeneously treated with the AIDA induction schedule at a single institution were included in the study. Twelve (10.5%) and 9 (8%) of the 114 patients expressed CD15 and CD56, respectively. CD15 expression identified a subset of patients with a classic morphologic subtype (92%), a prevalent association with a bcr1 expression (67%) with an unexpectedly higher frequency of relapses (42% vs 20% for the CD15- patients, p=0.03) and a low overall survival (OS) (median OS at 5 years 58% vs 85% for the CD15- patients, p=0.01). CD56 expression was detected only in patients with a classic morphologic subtype, a prevalent bcr3 expression (67%), high incidence of differentiation syndrome (55%), higher frequency of relapse (34% vs 20% for the CD56- population, p=0.04) and a low OS (60% vs 85% for the CD56- population p=0.02). We hereby confirm the negative prognostic value of CD56 and we show that the same applies also to cases expressing CD15. These aberrant markers may be considered for the refinement of risk-adapted therapeutic strategies in APL patients.

Topics: Adult; Biomarkers, Tumor; CD56 Antigen; Female; Fucosyltransferases; Humans; Immunophenotyping; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Male; Phenotype; Predictive Value of Tests; Prognosis; Survival Analysis

The decoction of the roots of Hemidesmus indicus is widely used in the Indian traditional medicine for the treatment of blood diseases, dyspepsia, loss of taste, dyspnea, cough, poison, menorrhagia, fever, and diarrhea. Poly-herbal preparations containing Hemidesmus are often used by traditional medical practitioners for the treatment of cancer. The aim of this study was to investigate the cytodifferentiative, cytostatic and cytotoxic potential of a decoction of Hemidesmus indicus's roots (0.31-3 mg/mL) on a human promyelocytic leukemia cell line (HL-60).. The decoction of Hemidesmus indicus was characterized by HPLC to quantify its main phytomarkers. Induction of apoptosis, cell-cycle analysis, levels of specific membrane differentiation markers were evaluated by flow cytometry. The analysis of cell differentiation by nitroblue tetrazolium (NBT) reducing activity, adherence to the plastic substrate, α-napthyl acetate esterase activity and morphological analysis was performed through light microscopy (LM) and transmission electron microscopy (TEM).. Starting from the concentration of 0.31 mg/ml, Hemidesmus indicus induced cytotoxicity and altered cell-cycle progression, through a block in the G0/G1 phase. The decoction caused differentiation of HL-60 cells as shown by NBT reducing activity, adherence to the plastic substrate, α-naphtyl acetate esterase activity, and increasing expression of CD14 and CD15. The morphological analysis by LM and TEM clearly showed the presence of granulocytes and macrophages after Hemidesmus indicus treatment.. The cytodifferentiating, cytotoxic and cytostatic activities of Hemidesmus indicus offers a scientific basis for its use in traditional medicine. Its potent antileukemic activity provides a pre-clinical evidence for its traditional use in anticancer pharmacology. Further experiments are worthwhile to determine the in vivo anticancer potential of this plant decoction and its components.

Topics: Antineoplastic Agents, Phytogenic; Apoptosis; Cell Adhesion; Cell Cycle; Cell Differentiation; Cell Survival; Chromatography, High Pressure Liquid; Dose-Response Relationship, Drug; Flow Cytometry; Fucosyltransferases; Granulocytes; Hemidesmus; HL-60 Cells; Humans; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Lipopolysaccharide Receptors; Macrophages; Microscopy, Electron, Transmission; Phytotherapy; Plant Preparations; Plant Roots; Plants, Medicinal; Time Factors

Acute promyelocytic leukaemia (APL) is a unique clinicobiologic entity that can be successfully treated with All-trans Retinoic Acid ATRA-based regimens. Some cases of acute myeloid leukaemia (AML) with nucleophosmin (NPM) mutations have an immunophenotype that is similar to APL. The objective of the study is to compare antigenic expression in a group of APL patients with that in AML patients with NPM mutations and an APL-like immunophenotype (CD15- CD34- HLA-DR-). A consecutive series of 40 APL and 12 NPM patients with an APL-like phenotype were included in the study. Immunophenotypic patterns were investigated by multiparametric flow cytometry. Promyelocytic leukaemia-retinoic acid receptor-α transcript type, NPM and FLT3 mutations were investigated using conventional methods. Statistically significant differences were found between APL and NPM-mutated AML in CD33, CD13, CD2 and CD110 reactivity. CD2 expression was absent in every patient with NPM-mutated AML. In addition, mean fluorescence intensity and the coefficient of variation (cv) of CD33 and CD13 showed statistical differences between the two groups for CD33 (p = 0.007) and a trend to significance for CD13 (p = 0.05). Furthermore, among 45 evaluable patients, CD110 expression statistically differentiates between the two groups: [2/33 (6%) in the APL group and 8/12 (66.6%) in the NPM-mutated AML (p = 0.014)]. However, these traits were subtle, raising the possibility of practical diagnostic challenges. In conclusion, CD110 and CD33 reactivity may be useful to distinguish APL from NPM-mutated AML with CD15, CD34 and HLA-DR negativity. Nevertheless, cytogenetic and molecular characterization is necessary to establish the accurate diagnosis of AML.

Topics: Adult; Antigens, CD; Antigens, CD34; Antigens, Neoplasm; Diagnosis, Differential; Flow Cytometry; fms-Like Tyrosine Kinase 3; Fucosyltransferases; HLA-DR Antigens; Humans; Immunophenotyping; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Neoplasm Proteins; Nuclear Proteins; Nucleophosmin; Proto-Oncogene Proteins c-bcr; Receptors, Thrombopoietin

The effects of arsenic trioxide (ATO), all-trans retinoic acid (ATRA) and granulocyte colony-stimulating factor (G-CSF), alone or in combination, were investigated by focusing on differentiation, growth inhibition and arsenic uptake in the acute promyelocytic leukemia (APL) cell line HT93A. ATO induced differentiation at low concentrations (0.125 µM) and apoptosis at high concentrations (1-2 µM). Furthermore, ATRA induced greater differentiation than ATO. No synergistic effect of ATRA and ATO was found on differentiation. G-CSF promoted differentiation-inducing activities of both ATO and ATRA. The combination of ATRA and G-CSF showed maximum differentiation and ATO addition was not beneficial. Addition of 1 µM ATRA and/or 50 ng/ml G-CSF to ATO did not affect apoptosis compared to ATO treatment alone. ATRA induced expression of aquaporin-9 (AQP9), a transmembrane transporter recognized as a major pathway of arsenic uptake, in a time- and dose-dependent manner. However, treatment with 1 µM ATRA decreased arsenic uptake by 43.7% compared to control subject. Although G-CSF addition did not enhance AQP9 expression in the cells, the reduced arsenic uptake was recovered to the same level as that in controls. ATRA decreased cell viability and addition of 50 ng/ml G-CSF to ATRA significantly increased the number of viable cells compared with that in ATRA alone treated cells. G-CSF not only promotes differentiation-inducing activities of both ATRA and ATO, but also makes APL cells vulnerable to increased arsenic uptake. These observations provide new insights into combination therapy using these three agents for the treatment of APL.

Topics: Antigens, CD34; Apoptosis; Aquaporins; Arsenic Trioxide; Arsenicals; Biological Transport; Biomarkers, Tumor; CD11b Antigen; Cell Differentiation; Cell Line, Tumor; Cell Proliferation; Granulocyte Colony-Stimulating Factor; Humans; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Oxides; Tretinoin; Up-Regulation

Acute promyelocytic leukaemia (AML3) is characterized by particular clinical and biological features. We report the cytology and the immunophenotype of 14 AML3 from which 3 were AML3v. A double negativity of HLA-DR and CD34 is found in 12 cases and aberrant expression of CD2 in 2AML3v. Aberrant expression of CD56 and CD22 was shown in, respectively, one case, CD15, CD65 and CD117 expressions were variable. Cytological diagnosis is often evident, although in some cases, it is not typical and immunophenotype will contribute to the diagnosis.

Topics: Antigens, CD; Antigens, CD34; Antigens, Differentiation, Myelomonocytic; Bone Marrow Examination; CD2 Antigens; CD56 Antigen; Cytological Techniques; Flow Cytometry; HLA-DR Antigens; Humans; Immunophenotyping; Karyotyping; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Proto-Oncogene Proteins c-kit; Sialic Acid Binding Ig-like Lectin 2; Tunisia

Acute promyelocytic leukemia (APL) is a subtype acute myeloid leukemia in which leukemic promyelocytes predominate in the bone marrow (BM). Rapid diagnosis is critical for treatment decision since all-trans-retinoic acid must be administrated promptly. The microgranular variant may be of difficult diagnosis, as it may be confused with other diseases on morphological grounds. The purpose of this study was to determine if the microgranular variant has the same antigenic profile as the classical hypergranular type. The immunophenotype of leukemic cells from the bone marrow of 50 patients, with the PML-RARalpha gene rearrangement confirmed by RT-PCR, was determined by flow cytometry using a large panel of 22 monoclonal antibodies and a polyclonal anti-TdT antibody. Thirty-four cases were classified as classical APL and 16 as microgranular APL. The immunophenotypic profile of the two subtypes was indistinguishable concerning the presence or absence of these antigens, including the absence of reactivity for the HLA-DR antigen. The simultaneous immunophenotypic combination of a unique major cell population, heterogeneous intensity of expression of CD13, and the typical pattern of CD15/CD34 expression were similarly present in the hypergranular and microgranular subtypes. Homogeneous expression of CD33 was observed in 76% of the classical APL cases and in 100% of the microgranular cases. Additionally, we have studied two cases of PLZF-RARalpha APL that also displayed the same immunophenotype described for classical APL. Thus, the immunophenotypic profile highly characteristic of the PML-RARalpha gene rearrangement was also observed in microgranular and PLZF-RARalpha variants of APL.

Topics: Adolescent; Adult; Aged; Antigens, CD; Antigens, CD34; Bone Marrow; CD13 Antigens; Child; Cytogenetic Analysis; Female; Flow Cytometry; Gene Rearrangement; Humans; Immunophenotyping; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Male; Middle Aged; Neoplasm Proteins; Oncogene Proteins, Fusion; Reverse Transcriptase Polymerase Chain Reaction; Translocation, Genetic

The cellular isoform of the prion protein (PrPC) is a small glycoprotein attached to the outer leaflet of the plasma membrane by a glycosylphosphatidylinositol anchor. This molecule is involved in the pathogenesis of prion diseases in both humans and animals. We have characterized the expression patterns of PrPC during human leukocyte maturation by flow cytometry with monoclonal antibodies to PrPC, the glycan moiety CD15, and the stem cell marker CD34. We observe that prion protein is present on CD34+ bone marrow (BM) stem cells. Although lymphocytes and monocytes maintain PrPC expression throughout their differentiation, PrPC is downregulated upon differentiation along the granulocyte lineage. In vitro retinoic acid-induced differentiation of the premyeloid line HL-60 into granulocyte-like cells mimics the suppression of PrPC in granulocyte differentiation, as both PrPC mRNA and protein are downregulated. These data suggest that selected BM cells and peripheral mononuclear cells may support prion agent replication, because this process is dependent on availability of PrPC. Additionally, retinoic acid-induced extinction of PrPC expression in HL-60 cells provides a potential model to study PrP gene regulation and protein function. Finally, these data suggest the existence of cell-specific glycoforms of PrPC that may determine cellular susceptibility to infection by the prion agent.

Topics: Antibodies, Monoclonal; Antigens, CD34; Bone Marrow Cells; Cell Differentiation; Flow Cytometry; Granulocytes; Hematopoietic Stem Cells; Humans; Leukemia, Promyelocytic, Acute; Leukocytes; Lewis X Antigen; Lymphocytes; Monocytes; Prions; RNA, Messenger; Tretinoin; Tumor Cells, Cultured

We have previously shown that HL-60 cells exposed to all-trans retinoic acid (ATRA) after treatment with a non-cytotoxic concentration of vincristine (VCR) result in granulocytic maturation and differentiation, suggesting that VCR might exhibit a synergistic action with ATRA in the treatment of acute promyelocytic leukemia. In this report, leukemic cells obtained from a patient with acute promyelocytic leukemia were exposed to 20 nM VCR for 1 h followed by 1 microM ATRA for 6 days. An increase in the expression of mature myelocyte antigens, CD11b and CD15, was observed as determined by flow cytometric analysis. Treatment of VCR or ATRA alone, however, did not have any effect on the expression of these mature myelocyte antigens of the leukemic cells. These results suggest that combined VCR and ATRA may be more efficient in the differentiation therapy of acute promyelocytic leukemia, particularly in those cases showing a slow response to ATRA therapy.

Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Antigens, Neoplasm; CD13 Antigens; Cell Differentiation; Female; Flow Cytometry; Humans; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Middle Aged; Remission Induction; Sialic Acid Binding Ig-like Lectin 3; Tretinoin; Vincristine

The Lewis x antigen (Le(x); Gal beta 1-4[Fuc alpha 1-3]GlcNac beta1-R), which is present on the surfaces of human cells, is also synthesized by the human helminthic parasite Schistosoma mansoni. We now report that IgM and IgG antibodies to Le(x) antigens are present in the sera of humans and rhesus monkeys infected with S. mansoni, whereas these antibodies are completely absent in uninfected individuals. The sera from infected humans and monkeys mediate specific complement-dependent cytolysis of human promyelocytic leukemic HL-60 cells, which bear surface Le(x) antigen. Furthermore, the major activity in sera from infected individuals toward HL-60 cells is due to anti-Le(x) reactivity.

Topics: Animals; Antibodies, Helminth; Complement System Proteins; Cytotoxicity, Immunologic; Enzyme-Linked Immunosorbent Assay; Flow Cytometry; Humans; Immune Sera; Immunoglobulin G; Immunoglobulin M; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Macaca mulatta; Schistosoma mansoni; Schistosomiasis mansoni; Tumor Cells, Cultured

The therapeutic potential of the IgM complement-fixing murine monoclonal antibody (mAb) PM-81 (anti-CD15) against acute myeloid leukemia (AML) was assessed in a SCID/hu leukemia model. Intraperitoneal (i.p.) injection of NB4 leukemia cells resulted in aggressive growth of leukemia cells in the peritoneal cavity of irradiated SCID/CB-17 mice. Flow cytometric analysis of human CD15, 33 and 45 expression, as well as cytologic examination, revealed that leukemia cells disseminated into the peripheral blood and multiple tissues of the mice. The approximately linear relationship between the injected leukemia cells and the subsequent leukemia cell proliferation provided a reliable model for monitoring the therapeutic effects of immunotherapy. Intraperitoneal injection of the mAb PM-81 markedly suppressed leukemia cell growth in this SCID/leukemia model. Most of the untreated mice died within 35-50 days of leukemia cell inoculation. Four weeks after inoculation of NB4 cells, five of nine mAb PM-81 treated mice had no solid tumor growth and six of nine had no detectable peritoneal exudate leukemia cells as determined by flow cytometry. In contrast, 100% of the mice in the untreated or control mAb groups were found to have both solid and peritoneal leukemia growth. In further experiments designed to evaluate the effects of therapy on survival, 50% (4/8) of PM-81 treated mice survived to 150 days, and had no detectable solid or suspension leukemia cells detectable at necropsy. In contrast, the median survival of untreated or negative control antibody-treated mice was 40 days (comparison to PM-81 treated; p = 0.006 and p = 0.03, respectively). The mechanism of leukemia cell suppression is not likely due to complement fixation since we could not demonstrate in vitro any cytotoxicity mediated by SCID mouse plasma. Further study is required to understand the mechanism of the antileukemia effect of PM-81 in this model.

Topics: Animals; Antibodies, Monoclonal; Antigens, CD; Cell Division; Chromosomes, Human, Pair 15; Chromosomes, Human, Pair 17; Complement System Proteins; Cytotoxicity, Immunologic; Female; Flow Cytometry; Humans; Immunoglobulin M; Immunophenotyping; Immunotherapy; Leukemia, Promyelocytic, Acute; Leukocyte Common Antigens; Lewis X Antigen; Lymphocytes; Male; Mice; Mice, SCID; Translocation, Genetic; Transplantation, Heterologous; Tumor Cells, Cultured

The reactivity of monoclonal antibodies from the 5th workshop Selectins/Selectin Ligands panel, directed to the sialylated Lewis(x) and sialylated Lewis(a) determinants, with the human breast carcinoma (BT-20, ZR-75-1 and MDA-MB-468) cell lines, human ovarian carcinoma cell line A2780, fibrosarcoma (HT-1080, B-6FS) and hematopoietic neoplastic (U-937, HL-60, K-562) cell lines were determined with the aid of flow immunocytofluorometry. The examined monoclonal antibodies to sialylated Lewis determinants reacted with examined breast carcinoma, but not with the examined ovarian carcinoma and fibrosarcoma cell lines.

Topics: Antibodies, Monoclonal; Breast Neoplasms; Epitopes; Female; Fibrosarcoma; Flow Cytometry; Fluorescent Antibody Technique; Humans; Leukemia, Promyelocytic, Acute; Lewis Blood Group Antigens; Lewis X Antigen; Melanoma; Neoplasms; Ovarian Neoplasms; Tumor Cells, Cultured

On fresh leukemic cells taken from 30 patients with acute promyelocytic leukemia (APL) the membrane expression of a series of adhesion molecules including beta 2 integrins (CD11a/LFA-1, CD11b/Mac-1), selectin ligands (CD15/Le(x), CD15s/Le(x)) and tyrosine-phosphatase isoforms (CD45RA, CD45R0) was analyzed. The expression of these molecules was also studied in nine of these patients following the APL cells' culture with and without all-trans retinoic acid (ATRA). The fresh APL promyelocytes expressed CD45RA and CD15s on their surface, while CD11a, CD11b, CD15, and CD45R0 were constantly absent. In vitro treatment with ATRA consistently increased the expression of CD15, CD11b, and CD45R0 on leukemic promyelocytes; these changes were paralleled by a decrease of CD45RA display. The expression of sialylated antigen CD15s was fully independent from CD15 suggesting a differential enzymatic regulation within this selectin ligand system. ATRA was, however, incapable of promoting the up-regulation of CD11a in APL. As a result, asynchronous phenotype (CD11a-, CD11b+, CD15+, CD15s+/-, CD45RA-, CD45R0+) was generated that is normally undetectable on maturing myeloid cells. In order to provide a further control a case of acute agranulocytosis was also investigated, in which > 75% bone marrow cells were arrested at the promyelocyte stage; these bone marrow cells showed a surface phenotype identical to non-leukemic promyelocytes (CD11a+, CD11b+, CD15+, CD45R0+, CD45RA-) with a spontaneous ability to differentiate in vivo towards the more mature stages of myeloid differentiation. We therefore suggest that in fresh and ATRA-induced APL cells distinct, regular phenotypic changes are identifiable that are probably associated with t(15;17) and not seen in normal and activated bone marrow.

Topics: Antigens, CD; Antigens, Differentiation; Cell Adhesion; Cell Adhesion Molecules; Cells, Cultured; Flow Cytometry; Humans; Immunophenotyping; Leukemia, Promyelocytic, Acute; Leukocyte Common Antigens; Lewis X Antigen; Lymphocyte Function-Associated Antigen-1; Macrophage-1 Antigen; Receptors, IgG; Tretinoin

It has been shown previously that multilineage human hematopoiesis is maintained within human fetal bone marrow (BM) fragments implanted into severe combined immunodeficient (SCID) mice. We describe here an application of this animal model, the SCID-hu mouse, to the study of human myeloid leukemias. BM cells from 8 patients with various types of myeloid leukemias were injected directly into human bone grafts in the SCID-hu mouse. Cells from 7 patients grew in the human marrow without spreading to the mouse marrow. Cells from 6 of these patients were successfully transferred in vivo to secondary SCID-hu recipients. The surface phenotype and the cytologic features of the leukemia cells were conserved during passage in vivo. Thus, human myeloid leukemia cells could be reproducibly propagated in the human marrow environment in SCID-hu mice. The differentiation of promyelocytic leukemia cells in the SCID-hu mice was induced by all-trans retinoic acid, suggesting that the biologic features of the leukemia cells were maintained as well. Finally, evidence for a leukemic progenitor cell population in one case of acute myelogenous leukemia was provided with this system. This model may provide a useful tool for studying the biology of human myeloid leukemia as well as for evaluating new therapeutic modalities for myeloid leukemias.

Topics: Animals; Antigens, CD; Antigens, Differentiation, Myelomonocytic; Bone Marrow; Humans; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid; Leukemia, Myeloid, Acute; Leukemia, Myelomonocytic, Acute; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Mice; Mice, SCID; Neoplasm Transplantation; Sialic Acid Binding Ig-like Lectin 3; Transplantation, Heterologous; Tretinoin

E-selectin has a "multi-recognition" capability in terms of epitope binding specificity, depending on adhesion conditions (static vs. low- or high-shear stress dynamic systems). Specifically, (i) adhesion based on expression of alpha 2-->3 sialylated Le(x) (SLe(x)) is prominent under static or low shear stress dynamic conditions; (ii) adhesion under high shear stress dynamic conditions does not depend on the known SLe(x) species, but rather on Lex with an adjacent unidentified sialosyl substitution, which shows different susceptibility to sialidases and antibodies compared to known SLe(x).

Topics: Antibodies, Monoclonal; Arthrobacter; Carbohydrate Sequence; Cell Adhesion; Cell Adhesion Molecules; E-Selectin; Epitopes; Humans; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Molecular Sequence Data; Neuraminidase; Newcastle disease virus; Recombinant Proteins; Stress, Mechanical; Tumor Cells, Cultured; Vibrio cholerae

In order to eliminate residual leukemic cells from the marrow of patients with acute myeloid leukemia (AML) prior to autologous bone marrow transplantation, the optimal conditions of utilization of three CD15 murine monoclonal antibodies (MoAb) were investigated. The VIM-D5 MoAb was used with rabbit complement (C'), whereas the 8.27 and SMY15A MoAbs were used in the presence of human C'. These antibodies were also tested after fixation on magnetic beads. In a culture assay in semi-solid medium with a mixture of normal marrow and 1% HL60 cells, a lysis of clonogenic cells greater than 99% was achieved with the three antibodies and two rounds of complement, or with antibody-coated magnetic beads. Cultures of leukemic clonogenic cells (CFU-L) were performed in 47 cases. An inhibition equal to or greater than 90% was achieved in seven cases with VIM-D5, 16 cases with 8.27 and 11 cases with SMY15A and C'. The correlation with cytotoxicity of fresh cells was low. Twenty cases were purged with antibody-coated beads. An inhibition equal to or greater than 90% was observed in 10 cases with VIM-D5, 11 cases with 8.27 and 12 cases with SMY15A. The mean recovery of normal CFU-GM was higher than 70% and that of BFU-E higher than 95% with any method of treatment. It is concluded that efficient marrow purging of clonogenic AML cells can be achieved in some cases without toxicity for normal progenitors. The addition of other MoAbs seems necessary to obtain a significant purge in a majority of cases.

Topics: Antibodies, Monoclonal; Antigens, CD; Antigens, Neoplasm; Bone Marrow Transplantation; Cell Separation; Complement System Proteins; Evaluation Studies as Topic; Flow Cytometry; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Humans; Leukemia, Myeloid, Acute; Leukemia, Promyelocytic, Acute; Lewis X Antigen; Microspheres; Neoplastic Stem Cells; Oligosaccharides; Preoperative Care; Transplantation, Autologous; Tumor Cells, Cultured; Tumor Stem Cell Assay