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.

Cortisol level as risk factor for malignant hematologic pathology in children exposed to ionizing radiation after Chornobyl accident. / STAN ERYTROÏDNOÏ, GRANULOTsYTARNOÏ TA TROMBOTsYTARNOÏ LANOK GEMOPOEZU NA ETAPAKh KhIMIOTERAPIÏ U DITEY̆ Z GOSTRYMY LIMFOBLASTNYMY LEY̆KEMIIaMY, IaKI ZAZNALY VPLYVU IONIZUIuChOGO VYPROMINIuVANNIa VNASLIDOK AVARIÏ NA ChAES.

OBJECTIVE: Determination of serum cortisol level in the initial period of acute leukemia in children, who exposed to ion izing radiation and other factors of Chornobyl accident, depending on their age and prognosis of disease. MATERIALS AND METHODS: The study involved 283 children residents of Kyiv, Zhytomyr and Chernihiv regions. There were 90 acute leukemia patients(AL) (ALL - 56, AML - 34), and 193 people of comparison group with anemia, leukemoid reactions and lymphadenopathy. We analyzed the type of comorbid somatic pathology, diseases in the genealogy, hematological parameters, cortisol levels in blood serum and irradiation doses in all children. In patients with AL expected median survival was calculated. RESULTS: In 28.9 % of AL children the initial cortisol content was below 200 nmol/l, in 7.8 % - higher than 500 nmol/l (in the comparison group 10.4 % and 17.1 % respectively). Among AL patients with cortisol levels below 200 nmol/l were significantly less amount of persons with chronic bacterial infections and persistent viral infections (CMV, EBV) and in the genealogy of these children allergic reactions, endocrine pathology diagnosed more often compared with patients, whose hormone levels was higher than 200 nmol/l (p < 0.05). Distribution of children from control group by gradations of cortisol, age groups, defined somatic pathology and diseases in genealogy had no difference. It is shown, that lower initial blood serum cortisol level in ALL children correlates to a greater probability of relapse (Rs = -0,67). In patients with AML a direct correlation between cortisol level and median survival was detected (Rs = 0,79). Children radiation doses were ranging from 0.08 mSv to 14.9 mSv, and there were slightly higher among residents of Zhytomyr region (8.4 ± 1.2 mSv) compared to other regions. However, these doses did not affect blood serum cortisol levels in children and the course of AL. CONCLUSIONS: These data suggest the need for correction and individualization of corticosteroid doses for optimization of AL patients treatment. Children, who have lower than normative serum cortisol levels are at increased risk of hema tologic pathology and they need for hematologic monitoring.