The utility of fluorescence in situ hybridization (FISH) analysis in diagnosing graft versus host disease following orthotopic liver transplant.

Graft versus host disease (GVHD) following liver transplant occurs in 0.1-2% of patients and portends a poor prognosis. Affected organs include skin, the gastrointestinal tract and bone marrow. We present the case of a 61 year old female who developed skin rash and pancytopenia following sex-mismatched second liver transplant for autoimmune hepatitis. Initial skin biopsies revealed vacuolar interface change, keratinocyte necrosis and a mild mononuclear superficial perivascular infiltrate. The bone marrow was markedly hypocellular with scattered CD8 positive T lymphocytes. FISH analysis revealed chimerism with the presence of male donor cells in the skin and bone marrow biopsies. This case illustrates the diagnostic utility of FISH in detecting the presence of donor-derived cells in tissues affected by GVHD.