Immunohistological analysis of CD59 and membrane attack complex of complement in muscle in juvenile dermatomyositis.

Objective: To assess the presence of CD59 and the deposition of membrane attack complex (MAC) of complement system in skeletal muscle from patients with juvenile dermatomyositis (JDM), in comparison to patients with muscular dystrophies (MD) and children with normal muscle biopsies.

Methods: Muscle specimens obtained for diagnostic purposes from 10 patients with JDM, 6 with MD, and 7 children whose biopsies showed normal histology were analyzed. Immunohistological staining was performed using Mab against CD59 (YTH 53.