Recovery of natural cytotoxicity after bone marrow transplantation

Reconstitution of non-MHC restricted cytotoxicity was followed in 7 and in 4 cases after auto- and allotransplantation, respectively. In autografted cases a high level of natural cytotoxicity, which exceeded the pre-transplant values, was seen at the beginning of hematological reconstitution. At that time, the high percentage of DR+ peripheral blood mononuclear cells (PBMC) was found, while the percentage of CD16+ cells was in the range of the pre-transplant values. A high level of cytotoxicity was a transient phenomenon. In all cases, 40 days after grafting the natural cytotoxicity was again in the range of the pre-transplant values. In allotransplantation the peak of cytotoxicity was seen soon after the beginning of hematological recovery and the activity decreased after 24 to 48 days after grafting.