Expression of anti-SRP19 antibody in muscle tissues from patients with autoimmune necrotizing myopathy.

This study aimed to investigate the role of anti-SRP19 antibody in muscle tissues of patients with autoimmune necrotizing myopathy. Immunohistochemistry staining was used to determine the expression of anti-SRP19 antibodies in muscle tissues of autoimmune necrotizing myopathy patients. Results demonstrated that anti-SRP19 antibody was expressed in 71.4% (20/28) of muscle tissue specimens from patients with autoimmune necrotizing myopathy. Anti-SRP19 antibody expression was mainly localized in cytoplasm of necrotic muscle fibers surrounding the small blood vessels and interstitial cells. There were no significant differences in the age, course of disease, muscle, and creatine kinase levels between patients with positive or negative expression of anti-SRP19 antibodies. The expression levels of anti-SRP19, serum anti-nuclear antibodies, as well as anti-Ro-52, anti- SSA, anti-Sm, and anti-Jo-1 antibodies were not significantly different among groups. This study demonstrates that anti-SRP19 antibody is highly expressed in muscle tissues of patients with autoimmune necrotizing myopathy, and suggests that this protein may be involved in the origin and progression of the disease.