Exposure to per- and polyfluoroalkyl substances (PFAS) and development of autoimmunity in humans and animals: a scoping review

PFAS are a group of persistent organic pollutants, that bioaccumulate and are associated with negative health effects. Reviews have suggested that the most critical effects of PFAS are on the immune system, but little is known of effects on development of autoimmunity. Our objective was to map and summarize available evidence concerning exposure to any PFAS and development/presence of autoimmunity, in humans and animals. We assessed studies reporting potential associations between PFAS exposure and autoimmune disease and/or autoantibodies. We searched MEDLINE, Embase, CENTRAL, Scopus, and Web of Science (02.15.2024) and conducted complimentary searches. Results were presented descriptively and we categorized autoimmune diseases and autoantibodies into relevant outcome groups. 51 studies were included, distributed in the following groups: Autoimmune thyroid disease, inflammatory bowel disease, rheumatoid arthritis, systemic lupus erythematosus, type 1 diabetes, celiac disease, other diseases and autoantibodies. Cross-sectional studies were most common, limiting opportunities for causal inference. 33 studies showed associations between higher PFAS and increased risk of autoimmunity, while nine studies found lower PFAS associated with increased autoimmunity risk. The results suggest that PFAS have negative health impacts with strongest evidence for celiac and inflammatory bowel disease, weaker evidence for rheumatoid arthritis, systemic lupus erythematosus and type 1 diabetes mellitus. No clear indications of association with autoimmune thyroid disease. The majority of the studies showed an association between PFAS and autoimmunity. There is a need for more longitudinal and dose-response studies, to improve our understanding of individual autoimmunity outcomes in the future.Protocol registration: OSF.io ( https://doi.org/10.17605/OSF.IO/3FEVQ ).