INTRODUCTION: This study aims to investigate the expression pattern of zonula occludens (ZO) proteins, namely occludin, claudin-1, tricellulin, junctional adhesion molecules (JAM), and ZO-1, -2, and -3 in nasal mucosal biopsies of individuals with and without allergic sensitization.
METHODS: Between August 2011 and August 2012, a total of 69 patients (38 males, 31 females; mean age 28.0 years, range, 18 to 61 years) who underwent surgery for nasal septum deviation were included in this cross-sectional study. All patients underwent skin prick test with environmental allergen mixtures. Cup forceps biopsy samples were obtained from the inferior turbinate during septoplasty. These samples were stained immunohistochemically for occludin, claudin-1, tricellulin, JAM, and ZOs. Staining intensity was graded semi-quantitatively using the H-Score.
RESULTS: Of all patients, 14 were atopic. Occludin, claudin-1, and JAM scores were significantly lower in the mucosal samples from atopic patients, compared to the non-atopic patients (median 142.5 vs. 288, 153 vs. 296, and 156 vs. 312, respectively; p<0.001 for all). The ZO-1, -2, and -3 proteins were significantly lower in atopic patients (p<0.001 for all). The tricellulin, located at the intersection of three epithelial cells, was not significantly different between the two groups (208.5 vs. 195, respectively; p=0.686).
DISCUSSION AND CONCLUSION: Expression of the structural proteins of ZO decreases in the upper airways of asymptomatic atopic patients. These findings indicate that ZO may be an important determinant of atopic sensitization and, therefore, may be a potential target in the treatment of allergic rhinitis.