We investigated the effect of topical steroids on clinical outcomes and related immune response of chronic rhinosinusitis with nasal polyp (CRSwNP) patients and in eradicating some polyps. We want to explore a new potential mechanism linked to Th-17 cells.Methods:
Prospective, double-blind, placebo-controlled studies with 24 allergic and nonallergic patients were randomized to either placebo or fluticasone furoate for 12 weeks. Assessment of clinical response, endoscopic score with biopsies of the inferior turbinate, and polyps before and after treatment were performed. Biopsies were stained for T-cells, eosinophils, neutrophils, and IL-17A/F.Results:
Steroid treatment improved the mean symptoms scores from 7.12 to 4.02 (P < .01) and the polyp score from 5.13 to 3.31 (P < .05), but the comparison with placebo was not statistically significant in nonallergics due to insufficient study power. Steroid treatment decreased eosinophil counts on allergics but not neutrophils or T-cells. The IL-17A/F expression was higher in nonallergics with high neutrophil counts and was inclined by steroids. Compared to baselines, IL-17 cells were significantly less in allergic individuals and were not observed in allergics and with high neutrophil counts.Conclusion:
Topical steroids were more effective on certain nasal polyp phenotypes. Identification of polyp phenotype might be essential to ensure a better therapeutic response to intranasal corticosteroids.