ELECTRON-MICROSCOPIC STUDY OF SCLERODERMATOUS CHRONIC GRAFT-VERSUS-HOST DISEASE

Background. Sclerodermatous chronic graft-versus-host disease (SC-GVHD ) resembles systemic scleroderma (SSD) closely, both clinically and hi stologically. Our purpose was to try to define the morphologic differe nces of collagen fibers between SC-GVHD and SSD. Materials and Methods . Using electron microscopy, we compared the morphology of collagen fi bers in a 15-year old girl with SC-GVHD with those of three patients w ith SSD. Results. In SC-GVHD, sclerosis is located in the superficial dermis and collagen fibers of irregular diameter are seen in the subep idermal area. In SSD, sclerosis is seen in the lower dermis and subcut aneous fatty tissue, and collagen fibers of irregular diameter are loc ated in the deep dermis. Some of the collagen fibers were degenerative in the superficial dermis in SC-GVHD. We observed low-density, round structures in cross sections of collagen fibers. Conclusions. The diff erence in initial location and morphologic appearance of collagen fibe rs may indicate a different pathogenesis in SC-GVHD compared to SSD.