[Demonstration of blocking factors in permanently surviving rat-kidney allograft recipients after short postoperative treatment with alloantiserums].

GvHR tests were performed on spleen cells of 9 recipients surviving rat renal allografts for more than 120 days. The recipients had undergone a short term ALS-treatment. The GvHR tests showed normal cell-mediated immunity. After splenectomy and again 18 days later LBNF1 skin was grafted to the renal recipients. After a further period of 18 days LBufF1 skin was grafted. After some delay the specific grafts were rejected. The unspecific skin was rejected in a normal way. Before and after skin grafting the authors could not find the lymphocytotoxin and hemagglutinin. Instead a blocking factor which inhibited the spontaneous allorosette formation was detected in the sera of recipients. The authors compared the results with passive enhanced renal recipients. The two groups did not differ significantly from each other.