Systemic lupus erythematosus in an African Caribbean population: incidence, clinical manifestations, and survival in the Barbados National Lupus Registry.

Abstract

To assess the epidemiology, clinical features, and outcomes of systemic lupus erythematosus (SLE) in the predominantly African Caribbean population of Barbados. A national registry of all patients diagnosed with SLE was established in 2007. Complete case ascertainment was facilitated by collaboration with the island's sole rheumatology service, medical practitioners, and the lupus advocacy group. Informed consent was required for inclusion. Between January 1, 2000 and December 31, 2009, there were 183 new cases of SLE (98% African Caribbean) affecting 172 women and 11 men for unadjusted annual incidence rates of 12.21 (95% confidence interval [95% CI] 10.46-14.18) and 0.84 (95% CI 0.42-1.51) per 100,000 person-years, respectively. Excluding pediatric cases (ages <18 years), the unadjusted incidence rate among women was 15.14 per 100,000 person-years. The principal presenting manifestations were arthritis (84%), nephritis (47%), pleuritis (41.5%), malar rash (36.4%), and discoid lesions (33.1%). Antinuclear antibody positivity was 95%. The overall 5-year survival rate was 79.9% (95% CI 69.6-87.1), decreasing to 68% in patients with nephritis. A total of 226 persons with SLE were alive at the end of the study for point prevalences of 152.6 (95% CI 132.8-174.5) and 10.1 (95% CI 5.4-17.2) per 100,000 among women and men, respectively. Rates of SLE in Barbadian women are among the highest reported to date, with clinical manifestations similar to African American women and high mortality. Further study of this population and similar populations of West African descent might assist our understanding of environmental, genetic, and health care issues underpinning disparities in SLE.