Background: We report a case of intestinal graft-versus-host disease (GVHD) in a syngeneic bone marrow transplant patient.
Methods: 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.
Results: 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.
Conclusion: 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.