CYTOPLASMIC BODY MYOPATHY - FAMILIAL CASES WITH ACCUMULATION OF DESMIN AND DYSTROPHIN - AN IMMUNOHISTOCHEMICAL, IMMUNOELECTRON MICROSCOPIC AND BIOCHEMICAL-STUDY

Muscle biopsy samples from five patients with cytoplasmic body myopath y (CBM) were investigated by immunohistochemical (antibodies to desmin , actin, dystrophin, spectrin, alpha actinin and utrophin), immunoelec tron microscopic (antibodies to desmin, actin and dystrophin) and bioc hemical (desmin, dystrophin, actin and utrophin western blots) methods . Using immunofluorescence it was shown that the centers of cytoplasmi c bodies (CB) were stained by anti-actin, anti-utrophin and three diff erent anti-dystrophin antibodies. The peripheries were labeled by the anti-desmin antibody. Moreover, fibers containing CB showed a markedly increased staining of their entire sarcoplasm with the anti-desmin an tibody. Using immunoelectron microscopy it was shown that anti-dystrop hin antibodies selectively stained the external limit of the central g ranular region. Anti-desmin antibody labeled the filamentous halo, and anti-actin antibody stained the central core and the radiating filame nts. Biochemical studies showed storage of desmin and dystrophin, both of normal molecular weight. Our results suggest that CBM should be co nsidered along with a wider group of intermediate filament pathologies that include desmin-storage myopathies.