PECULIARITIES OF DYNAMICS OF PERIPHERAL BLOOD CELL COMPOSITION IN CHRONICALLY-EXPOSED INDIVIDUALS IN THE PERIOD PRIOR TO LEUKEMIA DEVELOPMENT.

A retrospective analysis of the peripheral blood cell composition (PBCC) has been performed among 43 chronically-exposed Techa riverside residents later diagnosed with chronic myeloid leukemia (CML) or acute leukemias (AL). Prior to CML development, a significant increase in peripheral blood neutrophil count has been noted in exposed individuals for many years. Neutrophil count grew most significantly after reduction of exposure dose rate to red bone marrow (RBM) to ≤0.1 Gy, which was typical both for CML and AL. An increase of a relative neutrophil count remained in the CML latency period along with relative lymphocytopenia. Peculiarities of PBCC among individuals with AL at a later date were 'rejuvenation' of neutrophils in the period of maximum exposure and in leukemia latency period. During haematopoiesis restoration period, high mean values of mature neutrophils were detected in the majority of exposed individuals with AL together with decreased lymphocyte and eosinophil count. Later higher mean values of neutrophils remained in these individuals.