Antinuclear factor, smooth and striated muscle antibodies in Duchenne-type muscular dystrophy.

Antinuclear factors and antibodies to smooth and striated muscle were studied by the indirect immune fluorescence method in the sera of 19 children suffering from progressive muscular dystrophy. In 47% of the patients antinuclear factor positivity, in 65% anti smooth muscle antibody positivity, and in 26% antistriated muscle antibody positivity was found. Antibody to striated muscle was present in patients with serious advanced dystrophy and in patients unable to walk, while anti-smooth muscle antibody occurred in less serious cases, too. On the basis of the results, it is concluded that in genetically determined progressive muscular dystrophy a secondary autoimmune process develops owing to the degeneration of muscles as the disease progresses.