The Role of Fractional Exhaled Nitric Oxide in Diagnosing Asthmatic Type 2 Chronic Rhinosinusitis With Nasal Polyps

Abstract

Background Fractional exhaled nitric oxide (FeNO) is useful in the management of asthma and predicting the efficacy of standard corticosteroids and biologics. However, the diagnostic value of FeNO in asthmatic chronic rhinosinusitis with nasal polyps (CRSwNP) remains unclear. Objective We assessed FeNO levels in patients with CRSwNP and evaluated the diagnostic value of FeNO for screening type 2 CRSwNP (T2-CRSwNP) with asthma. Methods We enrolled 94 patients who were diagnosed with CRSwNP and underwent functional endoscopic sinus surgery. FeNO levels, the blood eosinophil percentage, total IgE, spirometry tests (FEV1/FVC), Lund–Mackay CT score, and percentage of patients with comorbid asthma were compared among CRSwNP subgroups. Spearman rank correlation test was used to assess the degree of association between variables. ROC curve analysis was conducted to evaluate the diagnostic capability to differentiate T2-CRSwNP based on clinical and histological classifications. Results FeNO levels and the blood eosinophil percentage were significantly higher in patients with T2-CRSwNP(h) based on histological data ( P < .05). FeNO was correlated with the blood eosinophil percentage ( r = 0.420, P < .001) and FEV1/FVC ( r = −0.324, P = .001). A FeNO level of 27 ppb had a good ability to discriminate patients with asthmatic T2-CRSwNP(h) (AUC = 0.848; 95% CI = 0.7602-0.9361; sensitivity = 90.9%; specificity = 63.9%). The optimal cutoff values for FeNO and the blood eosinophil percentage for diagnosing asthmatic T2-CRSwNP(h) were 68 ppb and 5.6% (sensitivity = 95.5%; specificity = 86.1%; AUC = 0.931; 95% CI = 0.8832-0.9791). In the diagnosis of severe T2-CRSwNP(c) based on clinical data, a FeNO level of 36 ppb showed the highest AUC (0.816; 95% CI = 0.7173-0.914; sensitivity = 72.7%; specificity = 79.2%). Conclusion FeNO is a useful marker for screening asthmatic T2-CRSwNP even prior to biopsy or asthma evaluation and may assist in selecting a proper treatment.

Exhaled Nitric Oxide as Biomarker of Type 2 Diseases

“…As reported by Park et al, FeNO levels and the blood eosinophil percentage were significantly higher in asthmatic patients with histological T2-CRSwNP as compared to those in patients with non-T2-CRSwNP (p < 0.05). A ROC curve analysis showed that a FeNO level of 27 ppb had a good ability to distinguish patients with asthmatic T2-CRSwNP (sensitivity = 90.9%; specificity = 63.9%), while the optimal cut-off values for FeNO and blood eosinophil percentage for diagnosing asthmatic T2-CRSwNP were 68 ppb and 5.6%, respectively (sensitivity = 95.5%; specificity = 86.1) [120].…”

Pulmonology for the rhinologist

“…In patients who are already prescribed ICS, persistent elevation of FeNO may indicate suboptimal adherence to treatment [80]. FeNO has the potential to predict nasal polyposis in the absence of serum eosinophilia [76 && ], and for screening asthmatics with CRSwNP [81]. FeNO levels have been shown to reduce after endoscopic sinus surgery in patients with eCRSwNP with asthma but not in patients without asthma or in non-eCRSwNP patients [82].…”