[Expression of MHC and cell adhesion molecules in muscular sarcoidosis]

Biopsied skeletal muscles from 5 patients with muscular sarcoidosis (nodular type; 1, and myopathic type; 4) were immunocytochemically examined. All biopsies presented granulomatous changes. Atrophic or regenerating muscle fibers adjacent to granuloma demonstrated compression or ischemic changes. In the center of the granuloma, CD68+ epitheloid cells and giant cells, and CD4+ T cells were localized. At the periphery of the granuloma, CD4+ T cells, CD8+ T cells, CD20+ B cells, and CD68+ macrophages were found. Expression of HLA-A,B,C was diffuse in the muscle fibers. Expression of HLA-DR and ICAM-1 was more prominent near the granuloma or perifascicular fibers, and that of LFA-3 was moderate in those lesions. VCAM-1 was expressed in endothelial cells and macrophages near the granuloma. Those findings indicate that interferon-gamma or TNF-alpha produced by infiltrating inflammatory cells may induce expression of these immunologic markers or adhesion molecules. Immunocytochemical differences between the nodular and myopathic forms of sarcoidosis are not evident, but either localization or abundance of granuloma in muscle bulks is relevant to weakness or atrophy of clinically affected muscle.