Skin biopsy in allogeneic and autologous bone marrow transplant patients: a histologic and immunohistochemical study and review of the literature.

Histologic criteria and grading system for diagnosis of cutaneous manifestations of graft vs. host disease (GvHD) have been established, and the diagnosis of high-grade GvHD is readily made by pathologists. There have been, however, increasing reports of skin rash occurring in patients treated with autologous bone marrow transplant (aBMT) that cannot be distinguished clinically or histologically from GvHD following allogeneic bone marrow transplant (alloBMT). We studied the histologic and immunohistochemical features of 25 skin biopsy specimens obtained from 22 patients with skin rashes who had undergone either aBMT or alloBMT, or who suffered from a malignancy. Tissue sections were immunoreacted with pan-T lymphocyte-associated antibody Leu 22 (CD43); pan-B antibody L26 (CD20); macrophage/myeloid antibody for CD68 antigens; and LN-3 antibody specific for HLA Class II antigens. The clinical suspicion of GvHD was confirmed in 8 of 10 alloBMT patients. Seven of the 10 aBMT patients also clinically diagnosed to have GvHD, had histologic changes consistent with Grades I, II, or III. The rest of the patients showed changes consistent with drug reaction. T-cell lymphocytes (Leu22), macrophages (CD68), and HLA-DR expression on Langerhans cells were in general more prominent in allogeneic chronic GvHD, but this was not statistically significant. No significant differences were seen in the degree of HLA-DR expression on endothelial cells and keratinocytes in any of the groups. The current histologic criteria are inadequate to differentiate cutaneous GvHD following alloBMT from the skin rash occurring in the setting of aBMT.(ABSTRACT TRUNCATED AT 250 WORDS)