Myelodysplastic Syndrome in Patients with Acute Radiation SyndromeFollowing the Chornobyl Nuclear Power Plant Accident

The MDS cases (n=3) among acute radiation syndrome (ARS) survivors after the ChNPP accident were analyzed. MDS diagnoses were based on FAB (1982) and WHO classifications and included the refractory anemia (RA) (patient D. with ARS grade III), refractory anemia with ringed sideroblasts (RARS) (patient B. with ARS grade III), and unclassified MDS (MDS-U) (patient S. with ARS grade I). Clinical management of MDS in ARS patients was analyzed taking into consideration the morphological, immunological, and cytochemical peculiarities of haemopoietic cells. The ARS diagnoses were confirmed in a survey on a regular basis using standard cytogenetic method. Described MDS cases in ARS patients may be the secondary MDS variants taking into consideration possible radiation-induced injuries of hematopoietic cell genome due to the high dose of IR (1.7-5.5 Sv). The possible role of previous irradiation in a range of occupational dose limits before the ChNPP catastrophe for patients D. and B. with ARS grade III, both with possible role of such a confounding factor as petroleum exposure for patient S. (ARS grade I) for the development of MDS cannot be excluded.