Down-Expression Of Kinin Receptors In Allergic Nasal Polyps Epithelia: An Immunohistochemistry Study

Objectives To investigate the expression of B1 and B2 receptors in patients with nasal polyps (NPs) compared to controls. Study Design Retrospective case series. Settings Single academic center. Subjects and Methods Nasal biopsies of patients with NPs were compared to inferior turbinates of control patients. Comparisons included basic demographics and comorbidities, intensity of inflammation, and immunohistochemical staining of B1 and B2 receptors measured by immunohistochemistry staining scores (ISSs). Results A total of 41 patients were enrolled, with 21 patients (51.2%) in the NP group and 20 patients as controls. No differences were found in the prevalence of allergic comorbidities and smoking between the groups. The NP group demonstrated significantly higher prevalence of moderate and severe mononuclear infiltrates compared to the control group (57.1% vs 5.3%, P < .001). The NP group had significantly lower B1 expression in smooth muscle compared to the control group (mean ISS 0.22 vs 1.56, P < .001, respectively) and significantly more B2 expression in epithelial cells (mean ISS 1.81 vs 0, P < .001, respectively). Conclusion Patients with NPs exhibit different expression patterns of B1 and B2 compared to control patients. This implies that bradykinin receptor regulation participates in the pathogenesis of NPs.