Associations between per- and poly-fluoroalkyl substance (PFAS) exposure and immune responses among women in the California Teachers Study: a cross-sectional evaluation

Abstract

Background Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that have been shown to cause or are related to various health outcomes and diseases.Methods In this cross-sectional study nested in the California Teachers Study cohort, we measured PFAS exposure (9 analytes) in serum, and further evaluated the 4 PFAS analytes (PFHxS, PFNA, PFOA, PFOS) with detection levels of > 80%, in relation to 16 systemic inflammatory/immune markers in two multiplex serum-based assays from blood collected at one point in time. Study participants (n = 722) were female, completed a questionnaire regarding various health measures and behaviors, and donated a blood sample between 2013–2016. The association between PFAS analytes and immune markers (dichotomized by median) were evaluated by calculating odds ratios (OR) and 95% confidence intervals (CI), in both linear and logistic regression models, adjusted for age.Results The median age of our study population was 61 years (range = 40–95 years), of whom 99.7% had detectable levels of at least one PFAS analyte. The prevalence of PFAS analytes was strongly correlated with age, with those aged 40–49 years (youngest group) having the lowest PFAS burden and those aged 75 + years (oldest group) with the highest detectable levels. Statistically significant positive associations were observed between each ng/mL increase in PFHxS (OR = 1.34), PFOA (OR = 1.15), and PFOS (OR = 1.53) levels with BAFF levels above the median (compared to below the median). There was a 1.47-fold increase of elevated PFHxS with TNF-RII (above median) and a 1.38-fold increase with IL2Rα. We observed statistically significant inverse associations between PFOA and IL6 (OR = 0.79), and between PFNA with sCD14 (OR = 0.86) and CD27 (OR = 0.80). Risk estimates for logistic regression models were consistent. No significant positive associations were observed between PFNA exposure and any immune marker.Conclusions PFAS exposure was associated with altered levels of circulating inflammatory/immune markers. If validated, our results may suggest potential immune mechanisms underlying associations between the different PFAS analytes and adverse health outcomes.