Dystrophin expression in skin biopsy immunohistochemical. Localisation of striated muscle type dystrophin.

ABSTRACT

Dystrophin is normally localized in smooth muscle fibers of various organs in experimental animals, and it has been shown to be defective in the smooth muscle fibers of the mdx mouse, including the myoepithelial cell layer of the sweat glands. We investigated dystrophin localization, using three antisera raised against different domains of skeletal muscle type of dystrophin, in the smooth muscle structures of the skin, using immunohistochemical methods with monoclonal antibodies against dystrophin, in 24 patients with various neuromuscular diseases, and in a normal control. Skin biopsy showed a strong dystrophin reaction in the arrector pili muscles and in the myoepithelial cells of the sweat glands of patients with congenital muscular dystrophy, polymyositis, distal myopathy, putative Duchenne muscular dystrophy carriers, myoglobinuria, neurogenic atrophy and in a normal control. A faint positive dystrophin reaction was seen in four patients with Becker muscular dystrophy, whereas it was absent in 3 patients with Duchenne muscular dystrophy. As our data suggest that immunohistochemical dystrophin expression in smooth muscle structures of the skin is similar to that observed in striated muscle, skin biopsy may represent an alternative way to ascertain dystrophin deficiency.