Dr. Muangchan is a Re- search Fellow in connective tissue diseases at the University of Western Ontario.
Association of C-reactive protein with high disease activity in systemic sclerosis: Results from the Canadian Scleroderma Research Group
Article first published online: 27 AUG 2012
Copyright © 2012 by the American College of Rheumatology
Arthritis Care & Research
Volume 64, Issue 9, pages 1405–1414, September 2012
How to Cite
Muangchan, C., Harding, S., Khimdas, S., Bonner, A., Canadian Scleroderma Research Group, Baron, M. and Pope, J. (2012), Association of C-reactive protein with high disease activity in systemic sclerosis: Results from the Canadian Scleroderma Research Group. Arthritis Care Res, 64: 1405–1414. doi: 10.1002/acr.21716
- Issue published online: 27 AUG 2012
- Article first published online: 27 AUG 2012
- Accepted manuscript online: 3 MAY 2012 10:25AM EST
- Manuscript Accepted: 13 APR 2012
- Manuscript Received: 17 NOV 2011
- Canadian Institutes of Health Research
- Fonds de la Recherché en Santé du Québec
- Scleroderma Society of Canada
- Scleroderma Society of Ontario
- Sclérodermie Québec and all other provincial chapters
- Cure Scleroderma Foundation
- Summer studentship from the Canadian Institutes of Health Research
- Summer studentship from the Canadian Scleroderma Research Group
- Summer studentship from Amgen Canada
This study was performed to determine the prevalence of elevated C-reactive protein (CRP) levels and the significance of CRP in clinical parameters in systemic sclerosis (SSc; scleroderma) patients.
Canadian Scleroderma Research Group data were used. Statistical comparisons were made for CRP levels ≤8 mg/liter versus >8 mg/liter, early (≤3 years from first non–Raynaud's phenomenon symptom) versus late SSc, and diffuse cutaneous SSc (dcSSc) versus limited cutaneous SSc (lcSSc). A survival analysis was analyzed between patients with normal versus elevated CRP levels.
A total of 1,043 patients (mean ± SD age 55.4 ± 12.1 years, mean ± SD disease duration of 11.0 ± 9.5 years) were analyzed; elevation of CRP level and erythrocyte sedimentation rate (ESR; >20 mm/hour) occurred in 25.7% and 38.2%, respectively. Mean ± SD baseline CRP level in dcSSc (11.98 ± 25.41 mg/liter) was higher than in lcSSc (8.15 ± 16.09 mg/liter; P = 0.016). SSc patients with an early disease duration had a higher mean ± SD CRP level (12.89 ± 28.13 mg/liter) than those with a late disease duration (8.60 ± 17.06 mg/liter; P = 0.041). Although not consistent in all subsets, CRP was significantly associated (P < 0.01) with ESR, modified Rodnan skin score (MRSS), worse pulmonary function parameters, disease activity, damage, and Health Assessment Questionnaire. CRP level seemed to normalize in many SSc patients over time. Total lung capacity <80% predicted, MRSS, and serum creatinine were predictors of elevated CRP levels in SSc (odds ratio [OR] 2.76 [95% confidence interval (95% CI) 1.73–4.40], P = 0.0001; OR 1.03 [95% CI 1.01–1.05], P = 0.005; and OR 1.005 [95% CI 1.001–1.010], P = 0.02, respectively). Survival for patients with elevated CRP levels was less than for patients with normal CRP levels (P = 0.001).
CRP level is elevated in one-quarter of SSc patients, especially early disease. It is correlated with disease activity, severity, poor pulmonary function, and shorter survival.