Systemic lupus erythematosus in Australian Aborigines: high prevalence, morbidity and mortality

Abstract

BACKGROUND: Racial differences occur in the incidence of systemic lupus erythematosus (SLE). It has been suggested that SLE occurs at a higher prevalence and with greater severity in Aboriginal Australians, but because of the small, widely distributed population base, this has not been well documented. AIMS: To confirm and document the clinical impression of an increased prevalence and severity of systemic lupus erythematosus (SLE) in Aboriginal Australians, and to identify prognostic indicators. METHODS: Top End Northern Territory (NT) Aborigines with SLE on 1 January 1984 or diagnosed thereafter were followed until 1 January 1991. Epidemiological, clinical and serological data were collected. RESULTS: Prevalence on 1 January 1991 estimated at 1:1900, at least twice the estimated prevalence in non-Aboriginal Australians. High frequencies of renal disease (62% with proteinuria > 0.5 g/day) and autoantibodies to the Sm antigen (29%) were identified, contributing to the high mortality. Five year survival rate was 60%, with 67% of deaths resulting from infection. CONCLUSIONS: There is a high prevalence of SLE in NT Aborigines. In view of probable under-recognition of mild cases the true prevalence is likely to be even higher. Although morbidity and mortality may have been overestimated for the same reason, both were found to be high. Improved living conditions and health care delivery may improve prognosis.