NEW YORK (Reuters Health)—Racial and ethnic disparities in systemic lupus erythematosus (SLE) incidence and prevalence are considerable, according to two new studies of data from California and Manhattan.
“The most important finding of the population-based California and New York registries is the confirmation of the racial and ethnic disparities of SLE, with the highest incidence and prevalence in African Americans followed by Asian/Pacific Islanders, Hispanics, and then whites,” says Dr. Peter M. Izmirly of New York University School of Medicine.
“These two registries provide contemporary estimates of the incidence and prevalence of SLE in populations who have been historically underrepresented in large-scale epidemiologic studies [Asian/Pacific Islanders and Hispanics],” he tells Reuters Health by email.
“Rheumatologists who care for lupus patients spanning all major racial and ethnic groups see the burden this disease takes on African-Americans, Hispanics and Asians. These findings provide support to what was already intuited, and they allow us to inform a wider audience of health care providers, such as primary care physicians, to think of lupus when patients in these demographic groups present with symptoms that could indicate disease,” says Dr. Izmirly, lead author of the Manhattan paper.
As reported online Sept. 11 in Arthritis & Rheumatology, in the California Lupus Surveillance Project (CLSP) and the Manhattan Lupus Surveillance Program (MLSP), researchers estimated the frequency of SLE occurrence among the 2.4 million total patients in these registries.1,2
The CLSP includes data acquired from hospitals, rheumatologists, nephrologists, commercial laboratories and a state hospital discharge database about residents of San Francisco County, California.
The MLSP collected data from administrative databases, hospitals and private rheumatologists about Manhattan residents.
In the California and Manhattan registries, the age-standardized prevalence rates in women per 100,000 were 458.1 and 210.9, respectively, 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.
Age-standardized incidence rates (per 100,000) in California and Manhattan were 30.5 and 15.7, respectively, in black women; 8.9 and 6.5 in Hispanic women; 7.2 and 6.6 in Asian women; and 5.3 and 6.5 in white women.
“Prevalence and incidence rates from the Manhattan and California programs are very similar to those from the initial programs in Georgia and Michigan, both overall and by race and sex. However, the Manhattan and California findings differed from those of the initial programs in that, for the first time, they were able to provide estimates for Asians and Hispanics,” Dr. Izmirly says.
Lead author of the California paper, Dr. Maria Dall’Era of the University of California, San Francisco, tells Reuters Health by email, “These registries were established with a large grant from the Centers for Disease Control and Prevention and are very important to maintain. Several years of intense work was required for case finding of all people with SLE living in San Francisco in a defined period of time. Now that the challenging work of creating the registries has been completed, it is highly beneficial to follow these patients over time to answer important questions about the progression, treatment, and outcomes of SLE in the various racial and ethnic groups.”
“In San Francisco,” Dr. Dall’Era notes, “we have received a second grant from the CDC to enable us to follow our patients in a longitudinal cohort and also to collect blood specimens to study genetics, epigenetics, and environmental exposures. Through our work, we hope to better understand the reasons underlying the racial and ethnic disparities of SLE observed in the registry: the biological, environmental, and social determinants of health and disease.”
In an editorial that accompanies the papers, Drs. Susan Manzi of the Allegheny Health Network in Pittsburgh, and Joan Merrill of the Oklahoma Medical Research Foundation in Oklahoma City, write, “With better clarity around the definition of lupus that covers more of the spectrum without losing specificity for the pathology and a broader and refined approach to case ascertainment, our understanding of the real burden of disease in the U.S. will only improve.”3
References
- Dall’Era M, Cisternas MG, Snipes K, et al. The incidence and prevalence of systemic lupus erythematosus in San Francisco County, Calif.: The California Lupus Surveillance Project. Arthritis Rheumatol. 2017 Sep 10. doi: 10.1002/art.40191. [Epub ahead of print]
- Izmirly PM, Wan I, Sahl S, et al. The incidence and prevalence of systemic lupus erythematosus in New York County (Manhattan), N.Y.: The Manhattan Lupus Surveillance Program. Arthritis Rheumatol. 2017 Sep 10. doi: 10.1002/art.40192. [Epub ahead of print]
- Manzi S, Merrill J. Lupus, the chameleon: Many disguises difficult to capture. Arthritis Rheumatol. 2017 Sep 10. doi: 10.1002/art.40190. [Epub ahead of print]
