Immunologic reactions at various stages after transplantation of cryopreserved bone marrow.

The dynamics in the formation of immunocompetent cells by cryopreserved (-196 degrees C) and native myelokaryocytes in the organism of lethally irradiated recipients has been investigated. A temporary delay in the onset of intensive accumulation of antibody-forming cells (AFC) in the spleen of cryopreserved bone marrow recipients has been demonstrated. This is likely due to a later accumulation of functional active antigens into sensitive cells of thymus origin. In irradiated mice receiving semiallogenic cryopreserved bone marrow the beginning of a secondary disease could be observed later. The initiation of which is mostly due to T-lymphocytes. The number of dead animals in this group on the 100th day of observation being significantly lower than that in the group with native semiallogenic bone marrow grafts. The change in the dynamics of formation of the immunocompetent cell pool in the organism of irradiated recipients receiving cryopreserved bone marrow is probably caused by the inhibiting effect of physico-chemical factors of low temperature preservation on processes of proliferation and differentiation of hematopoietic stem cells.