Perfluoroalkyl Substances Are Linked to Incident Chronic Spontaneous Urticaria: A Nested Case-Control Study.

Previous studies suggested immunotoxicity of perfluoroalkyl substances (PFASs), but contradictory findings were reported for the associations of PFASs with allergies. The current study aimed to investigate the association of serum PFASs with incident chronic spontaneous urticaria (CSU) in adults. A nested case-control study within a longitudinal cohort of 7051 government employees in China was conducted. Participants with urticaria at the baseline were excluded. During the first follow-up, 70 incident CSU cases were included, and 70 matched healthy controls were randomly selected. In serum samples collected at the baseline, eight PFASs were determined using the UHPLC-MS/MS approach. The median serum concentrations of perfluorobutanoic acid (PFBA) and perfluoroheptanoic acid (PFHpA) were significantly higher in participants with incident CSU. The area under the ethnicity, and marital status), drinking, and intake of and routine blood test), baseline. CSU, several serum bio-To investigate the potential mechanism for the association, we con-ducted a mediation effect model as PFAS (X)-+ biomarker (M)-+ CSU (Y). A biomarker was selected if it was significantly correlated with both PFAS and CSU. Specifically, a logistic model was used when CSU was the dependent variable, and a linear model was used when the biomarker was the dependent variable. The significance of the mediation effect was tested using the Bootstrap method with 1000 simulations, and the 95%