Interleukin-17A expression in patients with chronic rhinosinusitis and its relationship with clinical features

<sec id="sec14-0300060513478089">Objective To investigate the expression of interleukin (IL) 17A in Chinese patients with chronic rhinosinusitis (CRS) and analyse its correlation with clinical parameters. <sec id="sec15-0300060513478089">Methods Patients undergoing functional endoscopic sinus surgery and matched controls were included in this retrospective study. Clinical assessments (using a visual analogue scale of symptom severity, Johansson endoscopic score and Lund-Mackay computed tomography score) were performed preoperatively. Mucosal specimens were analysed for inflammatory infiltration and IL-17A expression, using immunohistochemistry. <sec id="sec16-0300060513478089">Results In total, 40 patients undergoing functional endoscopic sinus surgery and 16 controls were included in the study. IL-17A levels were significantly higher in tissues from patients with CRS (with or without nasal polyps) than in control tissues. In CRS, IL-17A expression tended to be higher in tissues with infiltrating neutrophils than in those with infiltrating eosinophils, but this difference was not significant. IL-17A expression in CRS was positively correlated with symptom severity, endoscopic findings and radiological appearance. <sec id="sec17-0300060513478089">Conclusions Expression of IL-17A was higher in Chinese patients with CRS than in controls, and was associated with infiltrating inflammatory cells, symptom severity, endoscopic findings and radiological appearance. These findings suggest that IL-17A may play a role in CRS pathogenesis and remodelling of nasal polyps.