Pathology of modified graft-versus-host disease in bone marrow allografted monkeys treated with antilymphocyte serum.

Lethally irradiated rhesus monkeys were used for bone marrow allografting and autografting. Monkeys receiving allogeneic bone marrow developed acute graft-versus-host reaction (GVHR) and had a mean survival time of 9.1 days as compared to autografted monkeys which survived above 500 days. Treatment with antilymphocyte sera (ALS) before allografting modified the GVHR and extended the survival time to an average of 43 days. Histologically, such animals showed evidence of "chronic" GVHR and septicemia secondary to a lack in lymphoreticular recovery. Subsequently, severe GI-tract infections followed which usually served as portal of entry for septicemia.