Chronic spontaneous urticaria is associated with elevated serum zonulin levels.

Autoimmunity is one of the potential mechanisms that has been proposed in the etiopathogenesis of chronic spontaneous urticaria (CSU). High serum zonulin levels are considered a marker for increased intestinal permeability, which has recently become an important research topic in autoimmune diseases. We designed this study to investigate the relationship between CSU and intestinal permeability based on serum zonulin levels. 65 patients with CSU and 65 age- and sex-matched healthy volunteers were included in the study. Serum zonulin levels were measured simultaneously with enzyme-linked immunosorbent assay (ELISA). Disease activity was assessed with the 7-day Urticaria Activity Score (UAS-7). The mean serum zonulin level was significantly higher in patients with chronic spontaneous urticaria (131.7 ± 49.7 pg/ml vs. 82.8 ± 29.4 pg/ml, p < 0.001). Patients with chronic spontaneous urticaria who had concomitant inducible urticaria exhibited higher serum zonulin levels compared with those without inducible urticaria (p = 0.014). No significant correlation was found between serum zonulin levels and age, sex, body mass index, disease duration, concomitant angioedema, and UAS-7 score. The study found that patients with CSU had significantly elevated serum zonulin levels compared to healthy controls, supporting the hypothesis that urticaria is associated with increased intestinal permeability.