Fractional exhaled nitric oxide, a potential biomarker for evaluating glucocorticoids treatment and prognosis in allergic bronchopulmonary aspergillosis

Abstract

Background: Allergic bronchopulmonary aspergillosis (ABPA) is characterized by enhanced T_H2 inflammatory response. Fractional exhaled nitric oxide (FeNO) measurement has been used as a valuable tool in predicting the development and management of asthma, another typical T_H2 inflammation. However, the clinical significance of FeNO in ABPA remains unclear.

Objective: To investigate the association between FeNO and the prognosis of patients with ABPA to provide a basis for the use of FeNO in evaluating the efficacy of glucocorticoids in ABPA treatment.

Methods: This study comprised 2 parts; 58 patients were enrolled in the retrospective study. Clinical indexes in patients with different prognoses were compared, and receiver operating characteristic curve analysis was used to determine the threshold value. The prospective observational study involved 61 patients who were regularly followed up at 4 to 6 weeks and 6 months since the initial treatment. Patients were grouped on the basis of baseline FeNO values; correlation analysis was performed in the clinical data.

Results: Different prognoses were observed between patients with high and low baseline FeNO values, with a threshold value of 57 parts per billion. The percentage of Aspergillus fumigatus-specific IgE, percentage of positive A fumigatus-specific IgG, and relapse/exacerbation rate differed significantly between the high and low FeNO groups. Patients with higher FeNO needed longer treatment duration and showed shorter interval between glucocorticoid withdrawal and the next relapse/exacerbation.

Conclusion: Our findings indicate that the level of FeNO is associated with the prognosis of ABPA. It can serve as an independent and valuable biomarker for evaluating the effectiveness of glucocorticoid treatment.