Graft-versus-host reaction after allogeneic hemopoietic tissue transplantation in rabbits conditioned with...

Graft-versus-Host Reaction (GvHR) was investigated in rabbits conditioned with a cyclophosphamide, which was given as a single injection of 110 mg/kg of body weight or as 4 injections of 50 mg/kg given on each of four successive days, before allogeneic bone marrow or spleen cells transplantation. The GvHR was of a chronic type. Splenomegaly was significant in the animals receiving spleen cell grafts, but not in the recipients of bone marrow transplants. In each of experimental groups delayed body weight gain and autoallergic phenomena were observed. Autoantibodies against erythrocytes, tested by direct Coombs test, were found in almost all graft recipients. This was a long lasting phenomenon since sensitized erythrocytes were found even after six months after transplantation. Cytotoxic autoantibodies against lymphocytes were present in the sera of about 20% of the recipients, and not longer than 30 days after transplantation. They proved not to be anti-RLA antibodies.