AUTHOR=Zheng Haoqi , Yu Xiuhua , Chen Yuquan , Lin Wenying , Liu Li 

TITLE=Effects of Inhaled Corticosteroids on Lung Function in Children With Post-infectious Bronchiolitis Obliterans in Remission

JOURNAL=Frontiers in Pediatrics

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/pediatrics/articles/10.3389/fped.2022.827508

DOI=10.3389/fped.2022.827508

ISSN=2296-2360

ABSTRACT=Background: Post-infectious bronchiolitis obliterans (PIBO) is a rare and irreversible chronic obstructive pulmonary disease with no specific treatment, especially for PIBO patients in remission. In this study, we evaluated the effects of continuous inhaled corticosteroids (ICSs) and intermittent ICSs on lung function in remission of PIBO. 
Methods: This was a retrospective study, and all the subjects we included were divided into Continuous ICSs group and Intermittent ICSs group according to treatment regimens. Patients in Continuous ICSs group received continuous ICSs (2 times a day), and patients in Intermittent ICSs group received intermittent ICSs (inhaled corticosteroids after acute respiratory tract infection or wheezing). Different lung function tests were performed at different ages. Tidal breathing lung function tests were performed in PIBO patients aged ≤ 5 years, and lung ventilation function test and bronchial dilation test were performed in PIBO patients aged > 5 years. Lung function was assessed at the beginning of follow-up and at the end of follow-up (1 year of ICSs). 
Results: After 1 year of ICSs, patients aged > 5 years old, forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) were significantly higher than at the beginning of follow-up. After 1 year of ICSs, the difference of VT/Kg, TPTEF/TE and VPEF/VE between the end and the beginning of follow-up in Continuous ICSs group, showing an upward trend. But those showed a downward trend in Intermittent ICSs group. FVC, FEV1 and maximal midexpiratory flow velocity 25-75% (MMEF25-75%) of Continuous ICSs group were significantly higher than at the beginning of follow-up. The difference of FEV1 and MMEF25-75% between the end of follow-up and the beginning of follow-up in Continuous ICSs group was significantly higher than that in Intermittent ICSs group. 52.94% of PIBO patients who aged >5 years old were positive for bronchial dilation tests.
Conclusions: ICSs can effectively improve lung function and relieve airway obstruction in patients >5 years in PIBO remission, especially continuous ICSs. Patients with PIBO may have reversible airflow limitation.