МОРФОЛОГИЧЕСКИЕ ОСОБЕННОСТИ КРОВЕТВОРЕНИЯ ПОСЛЕ ТРАНСПЛАНТАЦИИ АЛЛОГЕННОГО КОСТНОГО МОЗГА ПРИ МИЕЛОДИСПЛАСТИЧЕСКИХ СИНДРОМАХ

Summary . The morphology of hemopoiesis was studied in patients with myelodysplastic syndromes (MDS) during different periods after transplantation of allogenic hemopoietic stem cell (allo-HSC) with condition -ing of low intensity. Bone marrow aspirate specimens (n = 98) and bone marrow biopsy specimens (n = 94) were studied in 10 patents with primary MDS. Morphologic studies of hemopoietic tissue were carried out directly before allo-HSC transplantation with low intense conditioning and during different periods after transplanta-tion. Rapid replacement of the host hemopoiesis and hemopoiesis recovery were observed in MDS patients after allo-HSC transplantation due to healing of the donor transplant. Despite conditioning in the low intensity mode, hemopoietic tissue hypoplasia was detected during the early and late periods after transplantation, presum-ably because of stromal microenvironment damage, this limiting complete recovery of hemopoietic tissue. Good reparation of the erythroid and granulocytic hemopoiesis stems was observed after allo-HSC transplantation. The recovery of megakaryocytic stem was incomplete. Dysplastic changes in hemopoietic cells reduced significantly. Slight reversible secondary dysplastic changes were however found in erythrokaryocytes. In megakaryocytes the dysplastic changes were more stubborn and detected during the early and late stages after allo-HSC transplan-tation. Comparative analysis of bone marrow aspirate and biopsy specimens indicated that hemopoietic tissue recovery after allo-HSC transplantation in MDS patients developed during about the same periods as in other hematological malignancies. Hemopoietic tissue hypoplasia after allo-HSC transplantation was observed in the majority of patients over the entire period of observation. Morphologic studies of the signs of dysplasia of vari-ous hemopoietic stems in MDS showed significant reduction of dysmyelopoiesis after allo-HSC transplantation.Key words: