High-sensitivity C-reactive protein as an associate of clinical subsets and organ damage in systemic lupus erythematosus.

Objective: C-reactive protein (CRP) may play an anti-inflammatory role during the acute phase of inflammation and is also used as a marker of inflammation associated with cardiovascular disease. In the present study, we investigated the association between high-sensitivity CRP (hsCRP) and systemic lupus erythematosus (SLE) manifestations, autoantibodies, and organ damage.

Methods: In this cross-sectional study, 610 SLE patients from a prospective cohort had more than 1 hsCRP measurement. Organ damage was assessed using the Systemic Lupus International Collaborating Clinics (SLICC)/American College of Rheumatology Damage Index. Multiple linear regression models were used to adjust for age, gender, ethnicity, disease duration, body mass index, education, disease activity, current prednisone dose, statin use, and estrogen use.

Results: After adjusting for confounders, hsCRP was associated with myocarditis, cardiac murmur, interstitial pulmonary fibrosis, pulmonary hypertension, gastrointestinal lupus manifestations, and anemia. Anti-dsDNA antibodies and lupus anticoagulant were associated with hsCRP in unadjusted models, and these associations remained significant after adjustment for confounders. hsCRP levels were significantly higher in patients with pulmonary, musculoskeletal, and endocrine damage, and a total SLICC Damage Index score>or=1. After adjustment, hsCRP was associated with pulmonary, musculoskeletal, and total damage, but no longer with endocrine damage.

Conclusions: hsCRP is associated with a broad range of clinical features and organ damage in SLE, particularly in the pulmonary and musculoskeletal systems. This association holds true independent of sociodemographic, disease activity, and treatment factors and may be useful to identify high-risk SLE patients who would benefit from additional screening and surveillance studies.