Two new papers reveal striking racial and ethnic disparities in the incidence and prevalence of lupus, a systemic autoimmune disease that can affect virtually any organ system. The reports, which are published in Arthritis & Rheumatology, provide the latest information from lupus registries in California and New York.
In the reports from the California Lupus Surveillance Project and the Manhattan Lupus Surveillance Program, investigators estimated the frequency of lupus in a combined 2.4 million residents living in San Francisco and Manhattan. They found a similar overall age-adjusted annual incidence of lupus of 4.6 per 100,000. The age-adjusted prevalence was slightly greater in California than Manhattan (84.8 versus 62.2 per 100,000).
Women experienced higher rates of lupus than men, and the prevalence of lupus in both Hispanics and Asians was greater than that seen in Whites, but not as frequent as Blacks. The age-standardized prevalences in women per 100,000 for the California and Manhattan registries, respectively, were 458.1 and 210.9 for Black women, 177.9 and 138.3 for Hispanic women, 149.7 and 91.2 for Asian women, and 109.8 and 64.3 for White women.
"There is a paucity of population-based studies of incidence and prevalence of lupus among Asians and Hispanics in the United States," said University of California, San Francisco's Maria Dall'Era, MD, lead author of the California report. "These registries were able to address this deficiency and provide contemporary epidemiological estimates."
The findings indicate that doctors should be vigilant in looking for lupus in not only Black patients, but also in Asians and Hispanics. "Physicians should consider the diagnosis especially when patients come in with symptoms that could be consistent with lupus such as arthritis, rashes, and signs of kidney disease," said NYU School of Medicine's Peter Izmirly, MD, lead author of the Manhattan report. "Hopefully this can lead to earlier diagnosis of the disease and better care."
Additional studies are needed to determine the contributions of genetic and biological factors in addition to social and environmental factors that might play a role in racial and ethnic variation in the risk of lupus. "With this information, we will better understand how to diagnose and treat lupus in affected populations with the ultimate goal of disease prevention," said Dr. Dall'Era.