Immunotoxicity induced by topical application of sulfonic per- and polyfluoroalkyl substances (PFAS) in a murine model 2913

Description PFAS are a large group of synthetic compounds with unique chemical properties. PFAS are incorporated into consumer and industrial products (fire-retardant foams, cleaners, cosmetics, personal care products). While several legacy PFAS are identified by the NTP to be immunotoxic, not all have been tested. This study investigates dermal immunotoxic effects of occupationally relevant sulfonic acid PFAS in a murine model (PFBS, PFPeS, PFHxS, PFHpS) following 10- or 28-day dermal exposure of PFAS (0.3125-5%). Elevated levels of all PFAS were detected in the serum and urine, indicating absorption is occurring via the skin. PFPeS exposure decreased spleen weight and PFHxS and PFHpS decreased both spleen and thymus weights after 28-days of exposure. Investigation into immunotoxicity revealed both PFHxS and PFHpS significantly reduced the humoral immune response after a 10-day exposure with a reduction in both specific (PFC/106) and total (PFC/spleen) IgM antibody activity against sheep red blood cells. PFHxS and PFHpS exposure decreased total cellularity in the spleen and induced changes in CD4+ and CD8+ T-cells, B-cells, and dendritic cells. Phenotypic changes were also observed in the skin and draining lymph nodes after exposure to all compounds. These findings support dermal PFAS-induced functional deficits in adaptive and innate immune response. Further investigation into PFAS dermal exposure is needed to understand the hazards of skin exposure on immune function. Funding Sources This work was supported intramurally from the National Occupational Research Agenda (NORA) CAN 9390HTP.