Perfluoroalkyl substances (PFAS) exposure associated with immune markers: T & B lymphocytes and natural killer (NK) cells

Abstract

TPS 632: Health effects of flame retardants and plasticizers, Johan Friso Foyer, Floor 1, August 27, 2019, 3:00 PM - 4:30 PM Background. Perfluoroalkyl substances (PFAS) may be immunotoxic, but evidence on their possible association with counts of peripheral white blood cells (WBCs) and lymphocyte subsets is very scarce. This unique study addresses the association between 4 specific PFAS (PFHxS, PFOA, PFOS, and PFNA) and several immune function indicators. Methods. Both serum PFAS and White Blood Cells (WBCs) were measured in 42,782 (2005-2006) and 526 (2010) adults in the C8 Study, from an area with PFOA drinking water contamination in the Mid-Ohio Valley (USA). Additionally, the major lymphocyte subsets were measured in 2010. Cell counts were regressed on PFAS, with adjustment for potential confounders. Results. We found consistent positive and generally monotonic associations between numbers of total lymphocytes and PFHxS, PFOA, and PFOS in both surveys (range: 1.1% to 7.3% per PFAS IQR). Regarding lymphocyte subtypes, PFHxS was positively and strongly associated with T, B, and natural killer (NK) cells (range: 6.2%, 8.6%). PFOA and PFOS were both positively associated with number of CD3+ T and CD3+CD4+ T-helper cells (range: 3.0% to 6.9%), and PFOA with number of CD3+CD4+CD8+ T (‘double positive’) cells (10.5%). For PFOA but not the other PFAS, there were large differences in mean PFOA between water districts, but no exposure response between districts was evident. Other cells, particularly neutrophil percentage, showed slightly decreased trends associated with all PFAS (range: -2.8% to -0.6%).