[Detection of minimal residual disease in patients with acute myeloid leukemia]. / Vyiavlenie minimal'noi ostatochnoi bolezni u bol'nykh ostrymi mieloidnymi leikozami.

AIM: Detection of minimal residual disease (MRD) in patients with acute myeloid leukemia (AML) and the study of its correlations with duration of recurrence-free interval. MATERIAL AND METHODS: Bone marrow samples obtained from 37 AML patients before treatment were studied at two-color flow cytometry. The panel of monoclonal antibodies to T- and B-cell, myeloid antigens was used. The residual cells were estimated in 20 patients in remission. RESULTS: 78% cases were diagnosed to have an anomalous immunophenotype including coexpression of lymphoid and myeloid antigens, asynchronous expression of myeloid antigens. In the first remission the residual cells were detected in 20 patients due to aberrant antigen expression. The presence of MRD was stated if bone marrow contained more than 0.12% leukemic cells. The duration of the first remission and MRD correlated. 8 patients with MRD had remission for 3 to 6 months (median 4.7 months). 12 patients free of MRD were in remission for more than 6 months (for 8 to 26 months, median 19.7 months). The threshold level of the residual cells (0.12%) was confirmed statistically using the three-parameter probability model. CONCLUSION: This study confirms feasibility of using flow cytometry for detection of residual cells. MRD and duration of the first remission correlate. Long-term observation of large groups of AML patients will try the validity of the above statistical model.

[Immunoglobulin G monoclonal human anti-rhesus Rho(D) to prevent rhesus-incompatibility]. / Immunoglobulin G monoklonal'nyi chelovecheskii anti-rezus Rho(D) dlia profilaktiki rezus-nesovmestimosti.

RhD immunisation which follows pregnancy can be prevented by administration to the rhesus-negative mother of 20 micrograms anti-D immunoglobulin per 1 ml of D-positive fetal red cells in the maternal circulation. With the aim of substitution of polyclonal anti-D with monoclonal one we developed human-mouse cell lines producing anti-RhD IgG1 by fusing EBV-transformed human immune lymphocytes with murine myeloma. After several clonings and passages the EBV genome was eliminated from the cell lines. The antibodies were purified from culture supernatants using protein A affinity chromatography and tested for sterility, virus contamination, pyrogenecity, toxicity and DNA content. The monoclonals were compared with the standard polyclonal anti-RhD in in vitro and in vivo assays. In antibody-dependent cell cytotoxicity (ADCC) 2 of 4 studied monoclonals promoted greater RBS lysis than polyclonal anti-D at equivalent concentrations. Detection of binding site number of monoclonals anti-D revealed about 10,000/RBS D-determinants on DCe/dce erythrocyte which agrees with the data for polyclonal anti-D. Best in ADCC monoclonal anti-D sharply increased human autologous 51Cr-labelled rbc sensitised in vitro as well as accelerated clearance of RhD RBS from circulation of Rh-negative volunteers injected with 150 micrograms monoclonal anti-D. After clinical trial using of monoclonal anti-D is permitted in Russia.

[The production of granulocyte colony-stimulating factor by stromal bone marrow populations]. / Produktsiia granulotsitarnogo koloniestimuliruiushchego faktora stromal'nymi populiatsiiami kostnogo mozga.

Passaged bone marrow fibroblasts (PBMF) fail to maintain long-term hemopoiesis in culture unlike stromal adhesive layers of long-term culture of the bone marrow (LTCBM). What differs PBMF from LTCBM stromal cells in terms of the above ability we attempted to find out using immunocytochemical microscopy and flow cytometry. There were no differences as to protein production of the extracellular matrix, production of granulocytic-macrophagal colony-stimulating factor, stem cell factor, transforming growth factor beta, interleukin-1 beta and interleukin-6. The difference lies in inability of PBMF to produce granulocytic colony-stimulating factor (GCSF). It is evident that production of GCSF by stromal cells of the bone marrow is essential for maintenance of myelopoiesis in LTCBM.

[Flow cytometry in the determination of DNA aneuploidy in patients with acute leukemias]. / Protochnaia tsitometriia v opredelenii DNK-aneuploidii u bol'nykh ostrymi leikozami.

Bone marrow cellular DNA content was measured by flow cytometry in 107 adult patients with various types of acute leukemia. DNA-aneuploidy was detected in 28 of 107 patients (26%). In 18 patients with DNA-aneuploidy bone marrow was examined throughout 2-36 months. DNA-flow cytometry of bone marrow allows to determine DNA content in leukemia cells and distinguish hypodiploid, diploid, hyperdiploid and tetraploid DNA clones in patients with acute leukemia. In some cases this method allows monitoring of the minimal residual disease.

[The clinical significance of the immunological phenotype in non-Hodgkin's lymphomas]. / Klinicheskoe znachenie immunologicheskogo fenotipa nekhodzhskinskikh limfom.

To study immunological phenotype of tumor cells in the blood and tumor tissue of 68 patients with non-Hodgkin's lymphomas, the authors have used flow cytometry of lymphocytes and enzyme immunoassay in cryostat sections of lymph nodes with application of monoclonal antibodies to differentiating antigens of human lymphocytes. Histological types of lymphoma are shown to differ immunophenotypically. Differential antigens of prognostic and diagnostic value have been determined.

[The immunological phenotype and proliferative activity of the tumor lymphocytes in multiple myeloma]. / Immunologicheskii fenotip i proliferativnaia aktivnost' opukholevykh limfotsitov pri mnozhestvennoi mielome.

An immunological phenotype of blood lymphocytes and proliferative activity of tumor cells were studied using a panel of monoclonal antibodies to lymphocyte differential antigens and tracer 3H-thymidine, respectively, in 84 patients with multiple myeloma. CD-19 and CD38 antigens were identified as markers for circulating tumor lymphocytes. The count of CD38+ and CD71+lymphocytes correlated with the count of marrow plasmocytes including 3H-thymidine in the disease recurrence. Proliferative parameters of blood lymphocytes, plasmocytes and lymphocytes of the bone marrow were identical being, consequently, elements of the same tumor clone.

[Immunomorphocytochemical and immunofluorescent study methods in the immunodiagnosis of acute leukemias]. / Immunomorfotsitokhimicheskie i immunofliuorestsentnye metody issledovaniia v immunodiagnostike ostrykh leikozov.

Immunophenotyping results were compared for blast cells of the bone marrow and blood in a wide panel of monoclonal antibodies to differentiating antigens of the cells in various stages of hemopoiesis. The study was performed in acute leukemia (AL) patients using the immunocytochemical investigation (APAAP) and immunofluorescence (IF). Morphological evaluation of the marrow and blood involved cytochemical tests on glycogen, lipids, acid sulfated mucopolysaccharides, measurements of lysosomal enzymes and myeloperoxidase activities. Immunophenotyping was made with APAAP and IF. The results of the latter appeared approximately similar. APAAP proved more sensitive and informative in determination of blast cell phenotype and probable level of differentiation block. This may be used for earlier differential immunodiagnosis of acute leukemia variants. The immunological variants were found to correlate with some cytochemical indices pointing to the validity of more profound acute lymphoblastic leukemia classification to improve the diagnosis and treatment protocol designing.

[Monoclonal antibodies BCA-09 against blast cell surface antigen in acute myelomonoblastic leukemia]. / Monoklonal'nye antitela BCA-09, napravlennye k poverkhnostnomu antigenu blastnykh kletok pri ostrom mielomonoblastnom leikoze.

Data are presented on the study of BCA-09 monoclonal antibodies (MCA) produced by 2G3 hybrid cells (a new strain). The conventional method of somatic hybridization of mouse myeloma cells and splenocytes of mice immunized with peripheral blood leucocytes from a patient with acute myelomonoblastic leukemia (AMML) was used to obtain hybridomas. The study of BCA-09 MCA specificity has shown that in more than half of cases they reveal surface membrane antigen of leukemia cells in patients with AMML, and do not react with blast cells of patients with other variants of leukemia and lymphosarcoma, as well as with blood cells of normal subjects, and with some human cultural cell lines. BCA-09 MCA can be recommended for the differential diagnosis of AMML and other forms of lymphoblastoses.

[The use of a panel of monoclonal antibodies for immunologic prognosis of recurrence of acute lymphoblastic leukemia]. / Sozdanie paneli monoklonal'nykh antitel dlia immunologicheskogo prognozirovaniia razvitiia retsidivov ostrogo limfoblastnogo leikoza.

A method for early immunological prognosis of acute lymphoblastic leukemia (ALL) relapses has been presented. It is based on the dynamic phenotyping of lymphoid blood cells from the patients during remission by the indirect immunofluorescence test using a specially composed panel with monoclonal antibodies (MCA) to differentiation antigens of early lymphopoiesis stages. The panel composed for monitoring the population of leukemic cells during remission, contained 6 MCA selected from 40 MCA samples with the known specificity, basing on the principle of the highest reactivity with lymphoblasts from patients, and minimal positive reactions with lymphocytes from normal subjects. Blood mononuclear cells from 10 patients with ALL were subjected to immunophenotyping in the panel with MCA during remission, before each course of polychemotherapy. A retrospective analysis of the immunophenotyping data has shown that populations of lymphoid cells carrying antigens of early differentiation stages in amounts significantly exceeding the limits of the standard values (M +/- 3 delta) appear among blood lymphocytes, practically, in all the patients, 1-4 months before the relapse of ALL has been proved.

[Immunologic variants of acute lymphoblastic leukemia in adults and its correlation with cytochemical and various clinical parameters]. / Immunologicheskie varianty ostrogo limfoblastnogo leikoza vzroslykh v sopostavlenii s tsitochimicheskimi i nekotorymi klinicheskimi parametrami.

The authors provide data pertaining to the immunological phenotyping in the panel of monoclonal antibodies to various differentiating antigens of the leukemic cells in 27 patients with acute lymphoblastic leukemia (ALL). Based on the composition of the differentiating antigens of the leukemic cells the following immunological variants of the disease were identified: pre-B, pre-T and T-ALL--the thymic and mature (activated) ones. The phenotype was compared with the cytochemical parameters of the lymphoblasts of the identified immunological variants of ALL and with some clinical and hematological manifestations of the disease. The comparison of the data obtained during blast cell immunophenotyping with the cytochemical parameters and some clinicohematological findings suggests the development of a more fundamental classification of ALL in order to perfect the treatment of the patients suffering from ALL.

[Monoclonal antibodies to antigens found on the neutrophils, activated T-lymphocytes and blast cells in human acute leukemia]. / Monoklonal'nye antitela k antigenam, soderzhashchimsia na neitrofilakh, aktivirovannykh T-limfotsitakh i blastnykh kletkakh ostrogo leikoza cheloveka.

Two hybridomas secreting mouse cytotoxic monoclonal antibodies to in vivo and in vitro activated human T-lymphocyte and neutrophil surface membrane antigenic determinants have been produced. One of these monoclonal antibodies (Ta/H-2) appeared to be also specifically reactive to blast cells in the majority of non-T-non-B and T acute lymphoblastic leukemia patients.