Studies on the specificity of autoantibodies produced in systemic graft-vs-host disease.

Anti-erythrocyte antibodies were found in serum and on RBC of F-1 hybrid hamsters afflicted with systemic graft-vs-host (GVH) disease. These antibodies were shown to be reactive with antigenic determinants unique to hamster erythrocytes compared to heterologous erythrocytes and to non-erythrocytic hamster tissues. They fulfilled the criteria for true autoantibodies by failing to discriminate strain specificities among the domestically maintained isogenic hamster lines that were tested. It is suggested that the excessive production of these antibodies results from the allogeneic effect by which donor T-lymphocytes attack host B lymphocytes and stimulate heretofore quiescent self-reactive clones. Moreover,it is proposed that these autoantibodies can function as enhancing antibodies and subvert continued progression of GVH disease. In this regard, they resemble antibodies directed at allogeneic transplantation antigens that have been shown to attenuate and abort GVH processes.