Damage accrual in southern Chinese patients with systemic lupus erythematosus

Abstract

Objective: To study the predictive factors of damage accrual in a large cohort of southern Chinese patients with systemic lupus erythematosus (SLE).

Methods: A cohort of consecutive Chinese patients with SLE was recruited in 1998 and prospectively followed for 3 years. Demographic data, disease manifestations and activity, medication use, and damage scores were recorded. Organ damage was assessed using the SLE International Collaborating Clinics Damage Index (SDI), which was scored at study entry and then annually. Disease flares and new damage were recorded during followup visits. Predictive factors of new damage were studied by statistical analysis.

Results: The cohort consisted of 242 consecutive patients with SLE (221 women, 21 men; F:M = 10.5:1). All fulfilled at least 4 American College of Rheumatology criteria for the classification of SLE. At entry, mean age was 35.7 +/- 10.7 years and mean disease duration was 75.3 +/- 79 months. Ninety (38%) patients had damage. The mean SDI score at year 0 was 0.76 +/- 1.3 (range 0-8), and this increased significantly to 1.33 +/- 1.7 (range 0-9) at year 3 (p < 0.001). The most frequent organ damage at entry was musculoskeletal (26.5%), followed by damage in central nervous system (18.4%), renal (15.1%), and cardiovascular (12.4%) systems. The increase in SDI scores over the 3 year period was primarily caused by the increase in renal, musculoskeletal, and gonadal damage. Twelve patients died. Multiple regression revealed that the number of major disease flares and the use of cyclophosphamide were independent factors predictive of damage accrual. An increase in SDI scores was associated with mortality risk (OR 1.47 per 1 point, 95% CI 1.03-2.11, p = 0.04).

Conclusion: The damage scores of our SLE cohort increased significantly over 3 years. Severe disease flares and the use of cyclophosphamide predicted new damage. Increase in damage was associated with mortality risk. Judicious use of immunosuppressive agents to achieve prompt control of disease activity was essential in minimizing damage and improving survival of our patients with SLE.