Increased expression of HLA ABC class I antigens by muscle fibres in Duchenne muscular dystrophy, inflammatory myopathy, and other neuromuscular disorders.

The distribution of HLA ABC class I antigens in human skeletal muscle obtained by needle biopsy was investigated by means of a monoclonal antibody (W6/32) and an immunoperoxidase technique. Five samples from normal individuals and twenty-nine from patients with various neuromuscular disorders were examined. Normal muscle fibres and those from patients with congenital muscular dystrophy expressed little or no class I antigens, whereas muscle fibres of patients with myositis and various X-linked muscular dystrophies showed consistently strong expression. In other neuromuscular diseases expression was more variable. The presence of class I antigens on diseased muscle fibres may render them susceptible to cytotoxic T cells; these antigens may thus have an important role in the destruction of muscle fibres.