The Immunotoxicity of Two Novel Perfluoroether Acids Found in North Carolina’s Cape Fear River

Abstract

Novel perfluoroether acids (PFEAs) have been identified in surface waters of North Carolina and in the blood of some North Carolina residents. As some per- and polyfluoroalkyl substances (PFAS) are presumed immune hazards to humans, markers of immunotoxicity in young adult female and male C57BL/6 mice were observed following either 30-day oral exposure to perfluoro-2-methoxyacetic acid (PFMOAA), 30-day oral exposure to Nafion by-product 2 (NBP2), or 15-day oral exposure to a mixture of PFMOAA and NBP2. In-life observations were collected and endpoints included: organ weights, immunophenotype of lymphoid organs, natural killer (NK) cell cytotoxicity, liver peroxisomal enzyme activity, and the T-cell dependent antibody response (TDAR). In animals exposed to PFMOAA orally for 30 days the following changes were observed: liver weight statistically increased, in male animals peroxisomal enzyme activity statistically increased, and in male animals the TDAR was statistically suppressed. In animals exposed to NBP2 orally for 30 days the following changes were observed: liver weight statistically increased, spleen and thymus weight statistically decreased, NK cytotoxicity statistically decreased, liver peroxisomal enzyme activity statistically increased, and the TDAR was statistically decreased. In animals exposed to PFMOAA and NBP2 mixtures for 30 days the following changes were observed: one male group had statistically decreased bodyweight, some groups had alterations in organ weights. Our results indicate these novel PFEAs have immunosuppressive and immunomodulatory potential.