Native Americans Diagnosed with Lupus at Earlier Age, Study Reveals

Native American patients are diagnosed with systemic lupus erythematosus (SLE) at an earlier age and present with worse concurrent rheumatic disease symptoms than European Americans, a new study shows.

The study with those findings, “Unique clinical characteristics, autoantibodies and medication use in Native American patients with systemic lupus erythematosus,” was published in the journal Lupus Science & Medicine.

SLE tends to disproportionately affect certain minorities and socially marginalized populations with increased and earlier morbidity, and more co-occurring diseases.

In particular, Native American Indians have a higher prevalence of SLE — up to 1.7 times higher — more damage buildup, higher disease activity scores and higher SLE mortality rates, compared to other ethnic groups.

Native American patients also tend to experience disparities in healthcare, generally due to the high numbers of underinsured patients and having poor health status, along with other issues. These obstacles translate into less effective disease management and worse outcomes.

To better characterize SLE in Native American patients, researchers used information from the Lupus Family Registry and Repository (LFRR), which has a large, ethnically diverse cohort of patients with SLE. Researchers compared clinical and demographic features of Native American participants with SLE compared to those from other ethnic groups.

Study results indicated that Native Americans patients met the classification for diagnosis of SLE at a younger age — 29.89 years on average — compared to European Americans, who are diagnosed at 32.02 years on average.

Furthermore, more Native American patients had concurrent rheumatic diseases or symptoms, including Raynaud’s phenomenon, interstitial lung disease, Sjӧgren’s syndrome, and systemic sclerosis.

Compared to European Americans, Native Americans were more likely to have high levels of general autoantibodies — such as antinuclear antibodies — as well as more SLE-associated autoantibodies. IN addition, the presence of autoantibodies with unknown targets were more common in Native Americans compared to other ethnic groups.

Only 68% of Native Americans used hydroxychloroquine — a therapeutic frequently prescribed for SLE —  compared to 74% to 79% in SLE patients of other ethnicities.

Additionally, Native American patients had higher rates of methotrexate use compared to African-American and Hispanic patients. Native American patients also had higher azathioprine use compared to European American patients and higher mycophenolate mofetil use compared to European American and Hispanic patients.

These differences in treatment may be explained partly by concerns regarding retinopathies from co-occurring diseases such as diabetes. Furthermore, 27% of Native Americans in the group were from Latin America, where treatment for SLE patients is somewhat different.

“[Native American] patients are diagnosed with SLE earlier in life and present worse concurrent rheumatic disease symptoms than [European American] patients,” researchers said.

“These findings underscore the need for additional studies aimed at identifying molecular markers of disease that can aid earlier classification in Native American populations,” they added.