The three largest minority groups in the United States — blacks, Asians/Pacific Islanders, and Hispanics — are significantly more likely to experience severe manifestations of systemic lupus erythematosus than Caucasians, a new study shows.
The study, “Racial/Ethnic Differences in Prevalence of and Time to Onset of SLE Manifestations: The California Lupus Surveillance Project (CLSP),” was published in the journal Arthritis Care & Research.
Systemic lupus erythematosus (SLE) is a chronic, systemic disease with a higher prevalence among women and racial/ethnic minority groups in the United States.
However, despite the growing numbers of Asians/Pacific Islanders (API) and Hispanics in the United States, little is known about SLE manifestations in these populations.
In order to determine more accurate population-based estimates of incidence and prevalence of SLE among ethnic groups, the Centers for Disease Control and Prevention (CDC) funded four SLE registries across the United States.
The registry established in California, known as the California Lupus Surveillance Project (CLSP), had already reported a higher incidence and prevalence of SLE among Black, API, and Hispanic populations relative to Caucasians.
Now, researchers aimed to investigate the differences in SLE manifestations among each racial/ethnic group, focusing on the prevalence of SLE manifestations, as well as the risk of developing severe SLE manifestations.
“Previous epidemiologic studies suggest that in comparison to whites, blacks have a more severe presentation of symptoms at the time of diagnosis of SLE and a worse overall prognosis,” investigators stated.
The study included 724 SLE patients included in the CLSP. After adjusting for sex, age at diagnosis, and disease duration, they found substantial differences in the clinical manifestations of SLE experienced by each race/ethnicity.
Specifically, the three minority groups all had an increased prevalence of renal (kidney) manifestations compared to Caucasians; blacks experienced more neurologic manifestations, and both blacks and APIs had an increased prevalence of blood-related manifestations.
Lupus nephritis — a potentially life-threatening inflammation of the kidneys caused by lupus — was 2.4 times more likely to occur in blacks, 4.3 times more likely in APIs, and 2.3 times more likely in Hispanics.
Similarly, the risk for thrombocytopenia — a deficiency of platelets, which increases the risk of bleeding — was more than two times higher among the three minority groups compared to Caucasian patients.
Both APIs and Hispanics had nearly three times the risk of developing antiphospholipid syndrome — a disorder of the immune system that causes an increased risk of blood clots.
“We found 1) substantial differences in the prevalence of several clinical SLE manifestations among racial/ethnic groups, and 2) that blacks, APIs, and Hispanics are at increased risk of developing several severe manifestations following SLE diagnosis,” the researchers said.
“In lupus, disparities in health outcomes are striking and affect all of the major racial/ethnic groups in the United States. Alleviating these racial/ethnic disparities requires a multilevel approach, and as providers we need to be more vigilant about new symptoms in these patients and ensure communication that is culturally competent and breeds trust,” lead author Ernest Maningding, of the University of California, San Francisco, said in a press release.