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Selection of primers for polymerase chain reaction (PCR) as used in detection of the reconstructed genes of immunoglobulins and T-cells receptor in tumor cells in children with acute lymphatic leukemia is described in the paper. PCR potentialities and limitations in characterizing the monoclonality observed in primary acute lymphatic leukemia are demonstrated. Cross linkages of the heavy chain of immunoglobulins and of T-cell receptor were found between T- and B-linear acute lymphatic leukemia forms, but not between acute lymphatic leukemia forms and myeloleukemia in children.

The data on examination and treatment of 39 children with T-cell acute lymphoblastic leukemia (T-ALL) were assessed; all patients received ALL BFM-90-M treatment. The fraction of children with T-ALL among ALL patients in Belarus was 12.2% (pre-T-ALL--15, cortical T-ALL--46 and mature T-ALL--23%). Also, a subtype of T-ALL with atypical expression of markers was identified (13%). Overall 7-year survival in T-ALL patients was 47(20%). The worst prognosis was recorded in the T-ALL subgroup with atypical expression of markers (p < 0.001 as compared with the other subgroups). As for outcome--from best to worst, T-ALL subtypes ranged as follows: cortical T-ALL, mature T-ALL, pre-T-ALL and T-ALL with atypical expression of markers.

The first of case of adult T-cell prolymphocytic lymphosarcoma is reported which according to the natural course, cell composition of tumor, cell surface markers as well as expressed immune response to a wide spectrum of HTLV-1 gag an env encoded proteins can be classified as HTLV-associated adult T-cell leukemia. Diagnosis of the tumor alongside with identification of HTLV-1-infected individuals in the USSR emphasizes the need to stimulate research in HTLV-1-associated carcinogenesis in this country.

Correlation analysis of the clinical course and prognosis was made in 56 children with T-cell lymphoblastic tumors (acute lymphoblastic leukemia and lymphosarcoma) typed with the use of monoclonal antibodies obtained in this country. The frequency of T-cell marker detection among all immunological subvariants in acute lymphoid leukemia and lymphosarcoma proved to be similar (36.6 and 37%, respectively). In acute lymphoid leukemia type T1 of tumor cells prevailed (58%), while in lymphosarcoma type T3 (63%). T2 and T3-cell lymphoblastic tumors were characterized by the most severe clinical course.

It has been found that kinetic parameters of proliferation in a dominating clone of bone marrow blast cells with Ia-positive and Ia-negative phenotype, as well as with expression of myeloid differentiating antigens (ICO-GM1 and ICO-G2), or in the absence of these antigens, do not significantly differ in children with subvariants MO-M4 of acute nonlymphoblastic leukemia, sensitive and resistant to the therapy. A higher rate of the bone marrow blast cell population growth and a lower effectiveness of the combined chemotherapy have been recorded in children with T-cell and pre-B-cell acute lymphoblastic leukemia as compared to acute lymphoblastic leukemia with the phenotype of blast cells that have only Ia-like or "common" antigens.

The present investigation has demonstrated that it is advisable to specify different immunologic subvarieties of acute lymphoblastic leukemia based on the detection of superficial markers of blast cells. Acute lymphoblastic leukemia subvarieties are characterized by different clinical and hematological manifestations and differ with respect to the sensitivity to cytostatic therapy. The duration of remissions and lifespans was different in children belonging to different groups.

The study of the activity of nucleolus-forming areas in bone marrow and blood cells in 67 children with acute leukemia has shown the parameter variability depending on histogenetic affiliation, differentiation degree and on the proliferative activity of the cells.

Ultrastructural comparison was conducted between different immunological subvariants of T-cell acute lymphoblastic leukemia (T-ALL). Using the panel of monoclonal antibodies the cases of T-ALL were categorized into the following subvariants (early-T-, mature-T- and mature, activated-T-cell ALL). It has been shown that cells of these subvariants differ from each other in their ultrastructure and at the same time they reflect the submicroscopic features of corresponding normal counterparts.