[Immunomorphological and ultrastructural findings on the musculature in progressive scleroderma].

Muscle biopsies taken from 30 patients with generalized scleroderma were studied immuno-histologically as well as by light and electron microscopy. The immunological investigations have demonstrated that an increase of IgM and/or complement depositions in capillaries and in the walls of small arteries have been involved in most cases. Similar alterations were found in the subsarcolemmal zone. Vascular Ig-G precipitates were observed in the later stage of the disease only, whereas a positive reaction of fibrinogen have been proved in the most cases. By light and electron microscopy a variety of pathologic alterations have usually been found, but the most prominent changes involved were thickening of the capillary basement membrane and interstitial fibrosis. Scattered cellular infiltrates consisting of lymphocytes, histiocytes and plasmocytes were also seen either perivascularly or throughout the interstice. Around fibroblasts and capillaries, fine protocollagen fibrils and glycosaminoglycan filaments have been observed. They may partly represent fibrogenesis. Filamentous structures could be seen within the cytoplasm of numerous fibroblasts.