Acute graft-versus-host disease in recipients of bone-marrow transplants from identical twin donors.

Three patients with acute leukaemia received bone-marrow from identical twin donors after pre-transplant preparation with cyclophosphamide, cytosine arabinoside, and total body irradiation. Later clinical and microscopic changes in all three patients suggested cutaneous acute graft-versus host disease. In two of the recipients thrombolytic thrombocytopenia developed during the seventh week after transplantation, and platelet half-life was reduced to 9 h in one recipient (normal 3--4 days). It is suggested that acute graft-versus-host disease in bone-marrow recipients sometimes may result from an imbalance between autoreactive lymphocytes and lymphocytes which suppress their effect and not always from genetically determined histocompatibility differences between donor and recipient.