Predictors of organ damage in systemic lupus erythematosus: The Hopkins Lupus Cohort

Abstract

The Systemic Lupus International Collaborating Clinics/American College of Rheumatology (ACR) Damage Index (SDI) is the accepted measure of permanent organ damage in systemic lupus erythematosus (SLE). We analyzed data from a large SLE cohort to identify variables associated with rates of damage accrual as measured by the SDI. The study included 2,054 SLE patients (92% female, 56% white, and 37% African American) with a mean age at diagnosis of 33 years. The SDI score was calculated retrospectively at the time of cohort entry and prospectively during followup. The relationships between time-invariant patient characteristics and rates of damage accrual were assessed based on the damage score at the last available followup visit. The relationships between time-varying patient characteristics and damage accrual were assessed based on the timing of damage accrual during cohort participation. Overall, the SDI score increased at a rate of 0.13 per year. Higher rates of damage were observed for those who were older, male, or African American, had a lower income or education level, were hypertensive, were positive for lupus anticoagulant, or had proteinuria. During followup, the risk of damage was higher for those who were older, had more disease activity, had low complement levels, were positive for anti-double-stranded DNA, satisfied more ACR criteria for SLE, or were receiving corticosteroids. Lower risk was observed among patients receiving hydroxychloroquine. After adjustment for other variables, age, hypertension, and corticosteroid use emerged as the most important predictors of damage accrual. Our findings indicate that rates of damage vary in demographic subgroups, but much variation appears to be explained by hypertension and corticosteroid use. These data clearly point to the need for tight control of disease activity without reliance on corticosteroids.