Association of Fibrosing Myopathy in Systemic Sclerosis and Higher Mortality

• Published in: Arthritis care & research (2010) Vol. 69; no. 11; pp. 1764 - 1770
• Main Authors: Paik, Julie J., Wigley, Fredrick M., Shah, Ami A., Corse, Andrea M., Casciola‐Rosen, Livia, Hummers, Laura K., Mammen, Andrew L.
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.11.2017
• Subjects: Adult; Autoantibodies; Biopsy; Cohort Studies; Creatine; Creatine kinase; Cross-Sectional Studies; Electromyography; Female; Fibrosis; Fibrosis - diagnosis; Fibrosis - mortality; Gangrene; Health risk assessment; Humans; Inflammation; Male; Middle Aged; Mortality; Mortality - trends; Muscle, Skeletal - pathology; Muscular Diseases - diagnosis; Muscular Diseases - mortality; Myopathy; Necrosis; Population studies; Retrospective Studies; Scleroderma; Scleroderma, Systemic - diagnosis; Scleroderma, Systemic - mortality; Skin; Systemic sclerosis
• ISSN: 2151-464X; 2151-4658
• DOI: 10.1002/acr.23291

Objective To determine if a unique subtype of scleroderma muscle disease exists by comparing the clinical features of systemic sclerosis (SSc; scleroderma) patients with predominant fibrosis on muscle biopsy to those with inflammatory muscle histopathology. Methods This retrospective, cross‐sectional study included SSc patients with muscle weakness and an available muscle biopsy. Biopsies with fibrosis but without inflammation/necrosis were designated as “fibrosing myopathy,” and those with inflammation and/or necrosis were assigned a category of “inflammatory myopathy.” Clinical data, including features of SSc, serum creatine kinase (CK) levels, electromyography, autoantibody profile, and survival, were compared between the 2 groups. Results The study population consisted of 37 weak SSc patients, 8 with fibrosing myopathy and 29 with inflammatory myopathy. Compared to those with inflammatory myopathy, patients with fibrosing myopathy were more likely to have diffuse SSc skin subtype (87% versus 62%; P = 0.18), African American race (62.5% versus 37.9%; P = 0.20), and a lower mean ± SD forced vital capacity (55.5 ± 31.9 versus 66.4 ± 17.6; P = 0.23). They also had lower mean ± SD CK values (516 ± 391 versus 2,477 ± 3,511 IU/liter; P = 0.007) and lower aldolase values (13.8 ± 4.7 versus 27.3 ± 4.7; P = 0.01). Patients with fibrosing myopathy had a significantly higher mortality (5 of 8 [62.5%] versus 4 of 29 [14.3%]; P = 0.005). Conclusion Fibrosing myopathy is a unique histologic subtype of muscle disease among weak patients with SSc and is associated with significantly worse mortality compared to those with inflammation and/or necrosis on muscle biopsy.