PROGNOSIS OF THE COURSE OF CHORNOBYL-ORIGINATED ACUTE LYMPHOBLASTIC LEUKEMIA IN CHILDREN IN UKRAINE DEPENDING ON THE REASON OF STANDARD CHEMOTHERAPY INTERRUPTION. / PROGNOZ PEREBIGU GOSTRYKh LIMFOBLASTNYKh LEY̆KEMIY̆ ChORNOBYL'S'KOGO POKhODZhENNIa U DITEY̆ UKRAÏNY ZALEZhNO VID PRYChYN PERERV PRY PROVEDENNI STANDARTNOÏ KhIMIOTERAPIÏ.

OBJECTIVE: Estimation of the bone marrow haemopoietic status depending on the reasons and duration of breaks in a standard chemotherapy (BFM-ALL protocol) to predict the course of acute lymphoblastic leukemia (ALL) in chil- dren exposed to low doses of ionizing radiation after the Chornobyl accident. MATERIALS AND METHODS: The ALL patients (n = 34) were examined within 5 stages of a program chemotherapy. The clinical symptoms, hemogram and myelogram data were analyzed. The radiation dose on bone marrow, initial leuko- cyte count, variants and prognosis of ALL course were accounted. Days of the stopped chemotherapy, type and fre- quency of complications (septic processes, febrile neutropenia, toxic hepatitis, granulocytopenia degree), and the prognosis of disease course (child living status, i.e. alive or died) were estimated. RESULTS: There were abnormal differentiation processes and high percentage of lymphoblasts (86.2 ± 3.3) % in bone marrow in the 1st acute period. Hematological remission was established in all patients on the 33rd day of chemothe- rapy. In a half of cases the haematopoietic recovery occurred by a granulocyte-monocyte type. One third of patients presenting an erythroid type of haemopoiesis died later. The inverse correlation was found between the number of myelocaryocytes and disease prognosis (rs = -0.49). Breaks in chemotherapy for various reasons were recorded. The number of patients with granulocytopenia was greater at the phase 1 and 2 of protocol I and protocol M application, coinciding with a higher incidence of complications. An inverse correlations between the prediction of ALL course and sum of days of breaks between the protocol M and phase 1 of protocol II (rs = -0.56), as well as the duration of the phase 2 of protocol II (rs = -0.62) were found. The radiation dose on bone marrow was (5.37 ± 1.23) mSv. No relationship was found between the radiation doses, ALL variants and disease course. CONCLUSIONS: Prognosis of ALL course in children depends on the type of haemopoietic recovery and reasons of breaks in a standard chemotherapy. Interaction between the haemopoiesis functioning and microenvironment and that of their regulation are the key mechanisms of above-mentioned abnormalities, which is the basis for further research.

MYC gene rearrangements detected by interphase fluorescence in situ hybridization in diffuse large B-cell lymphomas. / MYC perebudovy dyfuznyh krupnoklitynnyh B-limfom, vyjavleni za dopomogoju interfaznoi' fluorescentnoi' IN SITU gibrydyzacii'

Diffuse large B-cell lymphoma (DLBCL) is the most common type of lymphoma, including approximately 30-40% of all B-cell non-Hodgkin lymphomas (B-NHL). Chromosomal translocations are the hallmark of genetic aberrations in B-lymphoma and are often associated with a specific subtype of B-NHL. MYC gene dysregulation due to chromosomal translocations is characteristic for the most cases of Burkitt's lymphoma. Objective. The goal of this study was to improve the diagnostic accuracy of DLBCL. Identification of chromosome 8 and 14 abnormalities including the translocation of MYC gene t(8; 14)(q24; q32) in substrate cells of lymph nodes was applied using the method of tri-color interphase fluorescence in situ hybridization (I-FISH). Materials and methods. Lymph node biopsy specimens of 17 patients with diffuse large B-cell lymphoma and three patients with Burkitt's lymphoma (including one participant of liquidation of consequences of the catastrophe at the Chornobyl NPP) were studied. The age of patients ranged from 10 to 66 years old (41.3 ± 3.7 average). Biopsy specimens fixed in paraffin. I-FISH-analysis was performed using the commercial test Vysis IGH/MYC, CEP 8 tri-color, dual fusion translocation probe (Abbott Molecular, USA). Results and conclusions. MYC gene and immunoglobulin heavy chain (IGH) gene translocations were found in four out of twenty persons. Consequently the I-FISH method allows identification of of MYC and IGH gene rearrangements in tissue cells substrate of lymphoma fixed in paraffin. Using this method the molecular-cytogenetic abnormalities were found in eight of twenty patients with B-cell lymphoma providing verification of the lymphoma diagnosis, prediction of their clinical course and advance in management i.e increase the effectiveness of therapy, in refractory lymphoma cases among others.