Capillary alterations in scleroderma

Electron microscopy of capillaries was performed in scleroderma skin. The main alterations were (1) gaps, vacuolization and eventual destruction of endothelial cells, (2) reduplication of the basal lamina, (3) perivascular cellular infiltrates consisting of lymphocytes, plasma cells, macrophages, or monocytes, and (4) fibroblasts and pericytes with enlarged, rough endoplasmic reticulum (RER) accompanied by perivascular fibrosis. Perivascular cellular infiltrates and endothelial cell damage appear to precede the stage of fibrosis.