Systemic lupus erythematosus in North American Indians: A population basedstudy

Objective. To evaluate the prevalence, disease course, and survival of pati ents with systemic lupus erythematosus (SLE) in a population of over 120,00 0 North American Indians (NAI), and contrast the results to those in the no n-Indian population. Methods. The regional arthritis center database and the medical records of all rheumatologists, hematologists. nephrologists. and general internists w ith > 1 patient with SLE were searched for cases of SLE diagnosed between 1 980 and 1996. A random survey of 20% of family physicians serving this popu lation suggested that > 85% of all SLE: cases were identified. Demographics , SLE Disease Activity Index (SLEDAI) scores, Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) damage s cores, clinical manifestations, and therapy for NAI were contrasted with th e results in Caucasians (CAUC). Results. We identified 257 cases meeting the ACR criteria for SLE diagnosed between 1980 and 1996, There were 49 NAI cases, resulting in a prevalence of 42.3/100,000, compared to a prevalence of 20.6/100,000 for the remainder of the population. NAI patients were younger at diagnosis, had higher SLED AI scores at diagnosis, and had more frequent vasculitis, proteinuria and c ellular casts. There were no treatment differences at diagnosis or at 2 yea rs, but NAI patients were significantly more likely to receive treatment wi th prednisone or immunosuppressives at the last clinic visit. The NAI patie nts had similar damage scores at diagnosis, but significantly higher scores at 2 years and at the last clinic visit. NAT ethnicity increased the likel ihood of death more than 4-fold. Conclusion. The prevalence of SLE was increased 2-fold in the NAI populatio n. NAI patients had higher SLEDAI scores at diagnosis and more frequent vas culitis and renal involvement, required more treatment later in the disease course, accumulated more damage following diagnosis, and had increased fat ality.