The Relationship between Serum Zonulin and Innate Immunity in Patients with Inflammatory Bowel Disease

Abstract

The aim of the study was to investigate the relationship between the serum zonulin and the cellular immunity in patients with ulcerative colitis (UC) and Crohn’s disease (CD). The study included 97 patients, 13 (13.4%) patients with CD and 84 (86.6%) patients with UC. The concentration of zonulin in the serum was studied using the ELISA kits. The investigation of the circulated leukocyte subpopulation was carried out through flow cytometry. The functional activity of the circulating neutrophils was studied using the absorption capacity of the monodisperse polystyrene latex particles and indicators of oxygen-dependent metabolism in the nitroblue tetrazolium test. The serum zonulin concentration in CD patients was significantly higher compared with UC patients (p = 0.003). The zonulin concentration directly correlated with the functional activity of the circulating neutrophils. Patients with a zonulin concentration > 472.4 pg/mL had a significantly higher number of band neutrophils (p = 0.0104), CD3+CD8+ cells (p = 0.0212), NK cells (p = 0.0161), and lower–CD19+ cells (p = 0.0034). Among the IBD patients, zonulin was associated with IBD severity. An increase in the serum concentration of zonulin was associated with an increase in the functional activity of circulating neutrophils and an increase in the number of CD3+CD8+ cells, NK cells, and a decrease in the number of CD19+ cells.