Predictive and Diagnostic Value of Nasal Nitric Oxide in Eosinophilic Chronic Rhinosinusitis with Nasal Polyps.

BACKGROUND: A hallmark of eosinophilic chronic rhinosinusitis with nasal polyps (eCRSwNP) is mucosal eosinophil-predominant inflammation. Nasal nitric oxide (nNO) is a known biomarker of eosinophilic inflammation in the upper airway. However, the utility of nNO measurement in the upper airway remains controversial. The present study aimed to compare the use of other clinical parameters with nNO to prediagnose patients with eCRSwNP from Central China. METHODS: From June 2019 to December 2019, 70 patients with CRSwNP undergoing endoscopic sinus surgery and 30 healthy subjects were enrolled. nNO measurements were performed in all of these subjects. Computed tomography scans, full blood count with differential analysis, and determination of total immunoglobulin E (total IgE) and plasma cytokines were performed before surgery. Receiver operating characteristic curves and logistic regression analysis were used to assess the predictive potential of the clinical parameters. RESULTS: We recruited 24 patients with eCRSwNP and 46 with noneosinophilic CRSwNP (non-eCRSwNP). In patients with eCRSwNP, nNO levels were significantly higher than those in patients with non-eCRSwNP (p < 0.0001). Blood eosinophil percentages and counts, total IgE, and CT-derived ethmoid sinus and maxillary sinus ratio (E/M ratio) were all significantly higher compared with those in patients with non-eCRSwNP (p < 0.05). To diagnose eCRSwNP, the highest area under the curve (0.803) was determined for nNO. At a cutoff of >329 parts per billion (ppb), the sensitivity was 83.30% and the specificity was 71.70%. However, the levels of plasma cytokines Th1/Th2 were not significantly different between the histological types of CRSwNP (p > 0.05). CONCLUSION: Measurement of nNO is useful for the early diagnosis of eCRSwNP.