Histological features of skin and rectal biopsy specimens after autologous and allogeneic bone marrow transplantation.

The histological appearances of skin and rectal biopsy specimens were studied in 31 bone marrow transplant recipients (13 autologous, 18 allogeneic) before transplant, at 28 days, at six months, and as soon as graft versus host disease (GVHD) was clinically suspected. Grades I and II skin changes were commonly seen in patients before transplant and in the autologous group after transplant, as well as in most of the allogeneic recipients with suspected GVHD. Epidermal lymphocytic infiltration was seen only in allogeneic recipients, with clinical GVHD following transplant, but this was not a consistent finding and no other histological features were seen which would distinguish early GVHD from changes caused by cytotoxic agents. Rectal biopsy specimens, however, were normal in patients before transplant and in autologous recipients at 28 days; single cell necrosis of crypt cells was seen only in six of 13 allogeneic recipients studied after transplant with clinical skin GVHD but no gastrointestinal symptoms. Skin changes greater than I and II are required for the histological diagnosis of GVHD. Rectal changes are more specific and may be present despite a lack of intestinal symptoms.