Adult onset reducing body myopathy

We report the case of a 28 year-old woman with left scapuloperoneal syndrom e since the age of 24. The course was slowly progressive and diffuse weakne ss was observed 4 years later. Serum creatine kinase levels were moderately elevated (x3 normal value) and EMG showed mixed neurogenic and myogenic pa tterns. Muscle biopsy showed type I predominance and numerous reducing bodi es in muscle fibers. Reducing bodies were strongly immunoreactive with anti bodies to dystrophin, alpha-sarcoglycan, vimentin and ubiquitin. Desmin imm unoreactivity was increased at the periphery of some reducing bodies but al pha B crystallin, alpha actinin, titin and nebulin were negative. Western b lot analysis showed an increase in dystrophin, vimentin and desmin expressi on. Ultrastructurally, reducing bodies were composed of tubulofilamentous m aterial, 17 nm in diameter, and immunoreactive with anti-Dys 2 antibody. Gr anulofilamentous material, immunoreactive with anti-desmin antibody was obs erved at the periphery of some reducing bodies. This report further highlig hts the proteinic composition of reducing bodies and shows that late onset reducing body myopathy may occur. (C) 1999 Elsevier Science B.V. All rights reserved.