This study published in Advances in Medical Sciences reports that nasal nitric oxide (NO) is a useful tool for the follow-up of patients with persistent allergic rhinitis (PER) and helps clinicians to estimate the level of treatment response.
In this study, 267 patients with mild and moderate-to-severe PER and 234 control subjects were randomised to antihistamine (AHS) plus leukotriene receptor antagonist (LKA) or intranasal steroid (INS) for six months. Baseline IgE and blood eosinophils were assessed and nasal fractional exhaled nitric oxide (FENO) was measured by electroluminescence device.
Nasal FENO, IgE, and eosinophils were higher in PER patients than in control subjects. In the control subjects, there were no significant correlations between FENO, total IgE, and eosinophil counts. In patients with PER, the level of nasal FENO was significantly correlated with total IgE and blood eosinophil counts.
Following treatment, clinical symptoms and nasal FENO were improved in allergic patients. Patients treated with INS responded better than patients treated with AHS plus LKA. Total IgE and eosinophils count were not significantly decreased after treatment.
These results suggest that nasal FENO may be a useful biomarker for diagnosis and for evaluating treatment response during follow-up in patients with PER.