Association of Fibrosing Myopathy in Systemic Sclerosis and Higher Mortality

Arthritis Care Res (Hoboken). 2017 Nov;69(11):1764-1770. doi: 10.1002/acr.23291.

Abstract

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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Intramural

MeSH terms

  • Adult
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Fibrosis / diagnosis
  • Fibrosis / mortality
  • Humans
  • Male
  • Middle Aged
  • Mortality / trends
  • Muscle, Skeletal / pathology*
  • Muscular Diseases / diagnosis*
  • Muscular Diseases / mortality*
  • Retrospective Studies
  • Scleroderma, Systemic / diagnosis*
  • Scleroderma, Systemic / mortality*