Acute intestinal graft-versus-host disease in a syngeneic bone marrow transplant recipient

We report a case of intestinal graft-versus-host disease (GVHD) in a syngeneic bone marrow transplant patient. Several days after receiving a bone marrow transplant from his identical twin for treatment of non-Hodgkin's lymphoma, a 47-year-old man developed a skin rash and diarrhea. A colonic biopsy on day +15 revealed characteristic changes of acute intestinal GVHD. Molecular studies (microsatellite DNA and HLA sequence-specific primer polymerase chain reaction analyses) confirmed the genotypic identity of donor and host and the improbability of transfusion-associated GVHD. This case illustrates that pathological evidence of GVHD does not absolutely require the presence of genetic differences between host and donor and questions existing concepts about the nature of cyclosporine-induced GVHD.