Background Perfluoroalkyl substances (PFAS) are a class of persistent organic pollutants found in nonstick products, water repellant fabrics, fire-retardant foams, and food packaging. Highly stable, the compounds persist in soil and water, bioaccumulate, and are found in the blood and tissues of animals and humans. Several PFAS, including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been associated with negative health effects through hormone disruption and immunologic dysfunction.

This ongoing study explores the associations between PFAS biomarkers, autoimmunity, and neighborhood-level social determinants of health among African Americans participating in a population-based cohort study.

Methods Data was utilized from a longitudinal study of Gullah African American patients with SLE and non-SLE controls. Demographics, medical history, Social Vulnerability Index (SVI) (incorporating socioeconomic status, household composition, race/ethnicity/language, and housing/transportation), antinuclear antibody (ANA) status and titer, serum PFOA concentration (ng/ml), and serum PFOS concentration (ng/ml) from in-person visits from 2003-2019 were included. Spatial overlays were applied to assign census tract identifiers and obtain SVI data for the participants. Statistical analysis using univariate and multivariate linear regression was performed.

Results A total of 81 participants, including 10 patients with SLE and 71 non-SLE controls were evaluated. All were non-Hispanic black, 85% female and 15% male (table 1). Participants with PFOS exposure had a 30% increase (worsening) in SVI for every one unit increase in the serum PFOS concentration (95% CI 0.04-0.60). PFOA concentration was not significantly associated with SVI, 95% CI -1.63-4.39. Adjusting for SLE, age, and gender, there was no significant association between SVI and PFOS (95% CI -0.004, 0.70) or PFOA (95% CI -2.24, 5.08).

Participants with a positive ANA had a statistically significant increase in SVI of 16% compared to those with a negative ANA, 95% CI 3.17-29.07. There was not a significant difference in SVI between patients with SLE and controls (95% CI -26.9-12.75).

Conclusion In our study of African Americans with and without SLE, PFOS, but not PFOA, exposure was associated with higher social vulnerability measured by the SVI. ANA positivity was also associated with higher SVI, although SLE diagnosis was not, likely due to the small number with SLE. These findings support continued studies of PFAS and other environmental contaminants which are associated with disparities in exposure, putting vulnerable communities at risk for adverse health impacts such as SLE.

Acknowledgements This work was supported by National Institute of Arthritis and Musculoskeletal and Skin Diseases grants P30AR072582 (JCO), K24AR068406 (DLK), and P30AR072582 (GSG). I would also like to acknowledge the participants in the Systemic Lupus Erythematosus in Gullah Health (SLEIGH) study.