Predictive and diagnostic value of fractional exhaled nitric oxide in patients with allergic rhinitis accompanied with asymptomatic bronchial hyperresponsiveness or chronic persistent asthma

doi:10.7504/nk2014050501

Abstract：Objective To investigate the predictive and diagnostic value of fractional exhaled nitric oxide (FeNO) in patients with allergic rhinitis accompanied with asymptomatic bronchial hyperresponsiveness (BHR) or chronic persistent asthma.Methods FeNO,nasal lavage,eosinophils (EOS) in induced sputum and methacholine bronchial provocation test (BPT) were performed in 20 patients with allergic rhinitis (AR) (male/female:9/11,aged 18-50 years),15 patients with AR and asymptomatic BHR (AR + BHR)(male/female:7/8,aged 18-50 years) and 20 patients with AR and chronic persistent asthma (AR + asthma)(male/female:8/12,aged 18-50 years).Correlation between FeNO and EOS was analyzed.Receiver operating characteristic (ROC) curve was applied to evaluate the predictive and diagnostic value of FeNO.Results The median and interquartile range of FeNO values in AR,AR + BHR and AR + asthma were 24.0 (15.5,35.5)pg/L,46.5 (35.0,63.0) pg/L and 61.5 (39.0,75.0) pg/L,respectively,with statistically significant difference among the groups (P ＜ 0.01).ROC curve was obtained using FeNO values to assess the diagnosis values.In AR + BHR group,the area under curve (AUC) was 0.842 (P =0.002) ;the sensitivity was 0.750 and specificity was 0.737 ;while the cut-off value was set as 34.0 pg/L.For the diagnoses of AR + asthma,AUC was 0.887 (P =0.000) ; the sensitivity was 0.750;and the specificity was 0.831,when taking 41.0 pg/L as the cut-off value.The percentages of EOS were (2.43 ± 3.56) ％,(7.36 ± 4.98) ％,(18.58 ± 11.26) ％ in AR group,AR + BHR group and AR + asthma group,respectively,with statistically significant differences among the groups (P ＜ 0.01).Conclusion Lower airway inflammation might exist in some extent in patients with allergic rhinitis.The mcasuremcnt of FcNO is simple and stablc with reliable predictive and diagnostic value for patients with allergic rhinitis accompany with BHR and chronic persistent asthma.