Systemic lupus erythematosus in three ethnic groups. IX. Differences in damage accrual

Abstract

Objective: To determine the factors predictive of damage in a multiethnic (Hispanic, African American, and Caucasian) LUMINA (lupus in minority populations, nature versus nurture) cohort of patients with systemic lupus erythematosus (SLE) with disease duration of < or =5 years at enrollment (T0).

Methods: Variables (socioeconomic/demographic, clinical, immunologic, immunogenetic, behavioral, and psychological) were measured at T0 and annually thereafter. Disease damage was measured with the Systemic Lupus International Collaborating Clinics Damage Index (SDI), and disease activity was measured with the Systemic Lupus Activity Measure. The relationship between the different variables and the SDI at the last visit (TL) was examined (mean followup from diagnosis to TL 61 months; adjusted for disease duration). Poisson regression was used to identify the independent association between the different variables and SDI scores at TL.

Results: Seventy-two Hispanics, 104 African Americans, and 82 Caucasians were included. One-half of patients had not accrued any damage. Caucasians had the lowest SDI scores at T0, and Hispanics had the highest scores at TL. Renal damage occurred more frequently among Hispanics and African Americans, while integument damage was more frequent among African Americans. Neuropsychiatric (20%), renal (16%), and ocular (15%) damage occurred most frequently among all patients. Independent predictors of SDI at TL were age, corticosteroid use (maximum dose at T0), number of American College of Rheumatology (ACR) criteria met, disease activity, and abnormal illness-related behaviors. Other variables were less consistently associated with damage accrual (poverty in African Americans, lack of HLA-DRB1*0301 in Hispanics, presence of HLA-DQB1*0201 and acute onset of SLE in Caucasians).

Conclusion: Damage in SLE occurs from the outset in some, but not all, patients; Hispanics accrue damage more rapidly. Disease factors (corticosteroid use, number of ACR criteria met, disease activity, and acute-onset type) are important, but age and abnormal illness-related behaviors also contribute to overall damage in SLE.