The value of small airway function parameters and fractional exhaled nitric oxide for predicting positive methacholine challenge test in asthmatics of different ages with FEV1 ≥ 80% predicted

Lili Hou; Huijuan Hao; Gang Huang; Jinkai Liu; Li Yu; Lei Zhu; Huahao Shen; Min Zhang

doi:10.1002/clt2.12007

The value of small airway function parameters and fractional exhaled nitric oxide for predicting positive methacholine challenge test in asthmatics of different ages with FEV₁ ≥ 80% predicted

Clin Transl Allergy. 2021 Mar;11(1):e12007. doi: 10.1002/clt2.12007.

Authors

Lili Hou¹, Huijuan Hao¹, Gang Huang², Jinkai Liu², Li Yu³, Lei Zhu⁴, Huahao Shen², Min Zhang¹

Affiliations

¹ Department of Respiratory and Critical Care Medicine, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
² Key Laboratory of Respiratory Disease of Zhejiang Province, Department of Respiratory and Critical Care Medicine, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, China.
³ Department of Pulmonary and Critical Care Medicine, Tongji Hospital, Tongji University School of Medicine, Shanghai, China.
⁴ Department of Respiratory and Critical Care Medicine, Zhongshan Hospital Affiliated to Fudan University, Shanghai, China.

Abstract

Background: Small airway function parameters (SAFPs) combined with fractional exhaled nitric oxide (FeNO) can predict a positive methacholine challenge test (MCT) for asthma diagnosis. However, their predictive utility in patients with forced expiratory volume in one second (FEV₁ ) ≥80% predicted within different age ranges remains unclear. This study aimed to assess the utility of SAFPs, alone or combined with FeNO, to predict a positive MCT in patients in two age groups (<55 and ≥55 years) with asthma-suggestive symptoms and FEV₁ ≥80% predicted.

Methods: We enrolled 846 Chinese patients with suspected asthma and standard spirometry, FeNO, and MCT findings. Using the area under the curves (AUCs), the utility of SAFPs, alone or combined with FeNO, for predicting a positive MCT was analyzed in a discovery (n = 534) and validation cohort (n = 312) in both age groups with FEV₁ ≥80% predicted.

Results: In the discovery cohort, the optimal cut-off values for predicting a positive MCT in patients aged <55 years (74.2% and 74.9% for forced expiratory flow (FEF)_50% and FEF_25%-75% , respectively) were higher than those in patients aged ≥55 years (65.0% and 62.9% for FEF_50% , FEF_25%-75% , respectively). However, the optimal FeNO value in patients aged <55 years (43 ppb) was lower than that in patients aged ≥55 years (48 ppb). FeNO combined with SAFPs (FEF_50% , FEF_25%-75% ) significantly increased the AUCs in both groups (≥55 years [0.851 for FEF_50% and 0.844 for FEF_25%-75% ]; <55 years [0.865 for FEF_50% and 0.883 for FEF_25%-75% ]) compared with a single parameter (p < 0.05). These findings were confirmed in the validation cohort. Compared with patients ≥55 years, those aged <55 years had higher and lower optimal cut-off values for SAFPs and FeNO, respectively. The AUCs of FeNO combined with SAFPs for predicting a positive MCT for asthma diagnosis were significantly higher than those of the individual parameters (p < 0.05) in both age groups.

Conclusions: There were age-group differences in the utility of SAFPs combined with FeNO for predicting a positive MCT. Patients with an asthma-suggestive history and a normal FEV₁ should be stratified by age when using SAFPs combined with FeNO to predict a positive MCT.

Keywords: age; asthma; fractional exhaled nitric oxide; methacholine challenge test; small airway; 关键词: 年龄, 哮喘, 呼出气一氧化氮, 乙酰胆碱激发试验, 小气道.

Abstract

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