Splenic PFAS Accumulation
The spleen is a primary lymphoid organ responsible for filtering blood, mounting antibody responses, and removing aged red blood cells. Post-mortem studies have detected PFAS in human splenic tissue, and animal studies demonstrate dose-dependent PFAS accumulation in splenic macrophages and lymphocytes. The spleen’s role in blood filtration concentrates PFAS from systemic circulation.
Splenic macrophages — which phagocytose pathogens and cellular debris — internalize PFAS-protein complexes from the circulation. PFAS impair macrophage phagocytic activity and cytokine secretion, reducing the spleen’s effectiveness as a primary immune defense.
Structural and Functional Splenic Changes
Rodent studies exposing animals to PFOA and PFOS show reduced spleen weight, altered white pulp architecture, and decreased germinal center formation — the sites where B cells differentiate into antibody-producing plasma cells. These structural changes correspond to functional impairments in vaccine antibody responses, which have been documented in both animals and humans.
Human studies of children in PFAS-exposed communities found significantly lower antibody titers following childhood vaccinations (diphtheria, tetanus, measles) compared to low-exposure controls. The effect size was clinically meaningful: children in the highest PFAS exposure quintile showed antibody levels below protective thresholds more frequently than low-exposure peers.
Implications for Immune Health
Reduced vaccine efficacy in PFAS-exposed children has significant public health implications for herd immunity. Pediatricians in PFAS-contaminated areas may consider antibody titer testing after childhood vaccinations to verify protective immunity, with booster doses if titers are inadequate.
Adults with high occupational PFAS exposure may similarly benefit from vaccine titer monitoring. Reducing PFAS exposure through water filtration may partially restore splenic immune function over time, though the reversibility of PFAS-induced splenic changes requires further study.