Evaluation of zonulin levels in hidradenitis suppurativa patients

Background: This study aimed to compare serum zonulin levels between patients with hidradenitis suppurativa (HS) and healthy individuals, and to evaluate the relationships between zonulin levels, disease severity, inflammatory markers, and metabolic parameters. Materials and Methods: This single-center, observational case–control study included 35 patients with HS and 35 age- and sex-matched healthy controls aged 18–65 years. Clinical data (Hurley stage) were recorded for patients, while body mass index (BMI), smoking, and alcohol consumption were documented for all participants. Inflammatory status was assessed using C-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and systemic inflammatory index (SII). Serum samples were stored at −80 °C and zonulin concentrations were measured using enzyme-linked immunosorbent assay (ELISA). Parametric or nonparametric statistical tests were used as appropriate, and multiple-group comparisons were performed with the Kruskal–Wallis test. Results: CRP and neutrophil levels were significantly higher in the HS group compared with controls (p < 0.05). No significant differences were found between the groups in platelet count, NLR, PLR, or SII. Serum zonulin levels did not differ significantly between HS patients and controls and showed no association with Hurley stage (p = 0.123). However, a significant difference was observed among BMI categories, with notably higher zonulin levels in overweight participants (p = 0.030). Conclusion: Serum zonulin levels do not independently reflect the presence or severity of hidradenitis suppurativa. Nonetheless, the significant association between zonulin and BMI supports an interaction between intestinal barrier integrity and metabolic processes. This finding underscores the importance of obesity management as part of a holistic approach to HS. Larger, multicenter studies including factors such as microbiota composition and diet that influence intestinal permeability are warranted to confirm these results. Keywords: Body Mass Index; C-Reactive Protein; Hidradenitis Suppurativa; Intestinal Permeability; Obesity; Smoking; Zonulin