Racial Disparity in Immune Response: Prospective Study in Obesity-Associated Lupus Patients 2260048

Abstract

Abstract Introduction Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by systemic inflammation and the production of autoantibodies (Ab), leading to multiple organ damage. Our recent retrospective data showed that obese patients have exacerbated lupus symptoms and overactive autoimmunity than non-obese lupus patients (pts). Here we further investigated the racial differences in immune cell profile and clinical features in obese-associated SLE pts. Methods Peripheral blood was collected from 60 consented SLE pts grouped by race and BMI levels. Immune cell profile was identified by flow cytometry. Clinical data including demographic information, BMI, SLE disease activity (SLEDAI), anti-dsDNA Ab, creatinine, urine protein, CRP, ESR, and complement levels were extracted from EPIC. Unpaired Student’s t-test was used for statistical analysis among the groups. Results SLE pts in this study were 75% Africa American (AA), 20% Caucasian American (CA), 2% Asian, 3% Hispanic/Latino, with 76.7% overweight/obese. Although there is no difference in CRP and complement levels, AA pts had significantly higher positive percentages of dsDNA Ab, skin rash, and nephritis history in all BMI groups comparing to CA pts. In addition, significantly higher levels of ESR (p < 0.05) and urine creatinine/protein (p < 0.05) were observed in AA pts than CA pts. Interestingly, significant increases of circulating T follicular helper (Tfh) cells (p < 0.005) and Th17 cells (p < 0.05) were found in overweight/obese pts comparing to non-obese pts, but no difference of these cells between AA and CA lupus pts. Conclusion Our data showed that AA (especially obese) lupus patients demonstrated similar T cell subsets to CA pts, but carried a significantly disproportionate burden of lupus, including higher incidence, more severe manifestations, and worse outcomes. Further study may provide biological insights into the pathogenesis of lupus racial diversity and potentially tailored therapy for high-risk lupus pts. Funding Source Collaborative Intramural Reseach Program (CIRP) in LSUHS and Ochsner Topic Categories Immune Mechanisms of Human Disease (HUM)