Post-infectious bronchiolitis obliterans in children: CT features that predict responsiveness to pulse methylprednisolone

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

BACKGROUND

Post-infectious bronchiolitis obliterans (PIBO) is a rare and irreversible chronic obstructive pulmonary disease with no specific treatment, especially for patients with PIBO in remission. In this study, we evaluated the effects of continuous inhaled corticosteroids (ICSs) and intermittent ICSs on lung function in the remission of PIBO.

METHODS

This was a retrospective study, and all the subjects we included were divided into continuous ICS group and intermittent ICS group according to treatment regimens. Patients in continuous ICS group received continuous ICSs (2 times a day), and patients in intermittent ICS 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 patients with PIBO aged ≤ 5 years, and the lung ventilation function test and the bronchial dilation test were performed in patients with PIBO aged more than 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 more than 5 years, forced vital capacity (FVC), and forced expiratory volume in 1 s (FEV₁) were significantly higher than at the beginning of follow-up. After 1 year of ICSs, the difference in V_T/Kg, TPTEF/TE, and VPEF/VE between the end and the beginning of follow-up in continuous ICS group shows an upward trend. But those showed a downward trend in intermittent ICS group. FVC, FEV₁, and maximal mid-expiratory flow velocity 25-75% (MMEF_25-75%) of continuous ICS group were significantly higher than at the beginning of follow-up. The difference in FEV₁ and MMEF_25-75% between the end of follow-up and the beginning of follow-up in continuous ICS group was significantly higher than that in intermittent ICS group. A total of 52.94% of patients with PIBO aged more than 5 years were positive for bronchial dilation tests.

CONCLUSION

Inhaled corticosteroids can effectively improve lung function and relieve airway obstruction in patients aged more than 5 years in PIBO remission, especially continuous ICSs. Patients with PIBO may have reversible airflow limitations.

When is asthma not guilty?

Asthma is a common childhood condition. Its prevalence in Saudi Arabia is high, increasing, and could exceed 20% at the current trajectory. Asthma is a syndrome with different clinical presentations and phenotypes. Many conditions are often misdiagnosed as asthma because they share the same symptoms, particularly coughing and shortness of breath; physical findings, such as wheezing; radiological findings, such as hyperinflation on chest X-ray; or even responses to asthma therapies, as in some patients with bronchiolitis. When treating the younger age group (>5 years old), there should be a high degree of suspicion of alternative causes when evaluating patients presenting with clinical features suggestive of asthma or patients who do not respond well to asthma therapies. This study will highlight common conditions that may mimic asthma and, as a result of incorrect treatment, unnecessarily expose patients to steroids and other therapies for extended periods. Furthermore, we seek to alert healthcare providers to common symptoms and signs that suggest a cause other than asthma and suggest when to refer the patient to subspecialists.

Follow-up on the therapeutic effects of a budesonide, azithromycin, montelukast, and acetylcysteine (BAMA) regimen in children with post-infectious bronchiolitis obliterans

Background

Post-infectious bronchiolitis obliterans (PIBO) is a rare, severe chronic lung disease without optimal treatment. Currently, treatment in children mainly relies on systemic corticosteroids, but long-term use of these drugs may lead to adverse reactions. This study aimed to evaluate the short-term efficacy of the budesonide, azithromycin, montelukast, and acetylcysteine (BAMA) regimen in paediatric PIBO patients and whether it can reduce systemic corticosteroid use.

Methods

This was a prospective study. From June 2017 to July 2020, patients diagnosed with PIBO at Yuying Children’s Hospital of Wenzhou Medical University were treated with the BAMA regimen for 3 months. Methylprednisolone was added only when the clinical manifestations did not improve or deteriorated. All patients were followed up every 2 to 4 weeks, and changes in clinical symptoms were recorded. Pulmonary function tests and high-resolution computed tomography (HRCT) were performed, and systemic corticosteroid use was recorded after the 3-month follow-up.

Results

A total of 75 patients with PIBO were included; overall, 54 patients completed the course of treatment. After treatment, the respiratory manifestations were improved in 37 patients (68.5%), but 4 patients (7.4%) showed decreased exercise tolerance, and 2 patients (3.7%) were readmitted to the hospital. Additionally, 17 (56.7%) of the 30 patients whose pulmonary function was re-examined showed improvement, and 28 (77.8%) of the 36 patients who underwent HRCT showed marked improvement. Importantly, 20 patients (54.1%) received systemic corticosteroids for 2 weeks or less, while 31.5% of patients used no corticosteroids.

Conclusions

The BAMA regimen effectively relieved clinical symptoms and signs of PIBO in children, improved pulmonary function and HRCT manifestations, and reduced the use of systemic corticosteroids.

Long-term course of bronchial inflammation and pulmonary function testing in children with postinfectious bronchiolitis obliterans

RATIONALE

Postinfectious bronchiolitis obliterans (PIBO) is a rare, chronic respiratory condition, which follows an acute insult due to a severe infection of the lower airways.

OBJECTIVES

The objective of this study was to investigate the long-term course of bronchial inflammation and pulmonary function testing in children with PIBO.

METHODS

Medical charts of 21 children with PIBO were analyzed retrospectively at the Children's University Hospital Frankfurt/Main Germany. Pulmonary function tests (PFTs) with an interval of at least 1 month were studied between 2002 and 2019. A total of 382 PFTs were analyzed retrospectively and per year, the two best PFTs, in total 217, were evaluated. Additionally, 56 sputum analysis were assessed and the sputum neutrophils were evaluated.

RESULTS

The evaluation of the 217 PFTs showed a decrease in FEV1 with a loss of 1.07% and a loss in z score of -0.075 per year. FEV1/FVC decreased by 1.44 per year. FVC remained stable, showing a nonsignificant increase by 0.006 in z score per year. However, FEV1 and FVC in L increased significantly with FEV1 0.032 L per cm and FVC 0.048 L/cm in height. Sputum neutrophils showed a significant increase of 2.12% per year.

CONCLUSION

Our results demonstrated that in patients with PIBO pulmonary function decreased significantly showing persistent obstruction over an average follow-up period of 8 years. However, persistent lung growth was revealed. In addition, pulmonary inflammation persisted clearly showing an increasing amount of neutrophils in induced sputum. Patients did not present with a general susceptibility to respiratory infections.

Chest imaging findings of chronic respiratory disease in HIV-infected adolescents on combined anti retro viral therapy

Early treatment with combination antiretroviral therapy (cART) has improved survival of children perinatally infected with HIV into adolescence. This population is at risk of long term complications related to HIV infection, particularly chronic respiratory disease. Limited data on chest imaging findings in HIV-infected adolescents, suggest that the predominant disease is of small and large airways: predominantly bronchiolitis obliterans or bronchiectasis. Single cases of emphysema have been reported. Lung fibrosis, lymphocytic interstitial pneumonitis, post tuberculous apical fibrocystic changes and malignancies do not feature in this population. Chest radiograph (CXR) is easily accessible and widely used, especially in resource limited settings, such as sub Saharan Africa, where the greatest burden of HIV disease occurs. Lung ultrasound has been described for the diagnosis of pneumonia in children, pulmonary oedema and interstitial lung disease [1-3]. The use of this modality in chronic respiratory disease in adolescents where the predominant finding is small airway disease and bronchiectasis has however not been described. CXR is useful to evaluate structural/post infective changes, parenchymal opacification and nodules, hyperinflation or extensive bronchiectasis. CXR however, is inadequate for diagnosing small airway disease, for which high resolution computed tomography (HRCT) is the modality of choice. Where available, low dose HRCT should be used early in the course of symptomatic disease in adolescents and for follow up in children who are non responsive to treatment or clinically deteriorating. This article provides a pictorial review of the spectrum of CXR and HRCT imaging findings of chronic pulmonary disease in perinatally HIV-infected adolescents on cART and guidelines for imaging.

Prediction of postinfectious bronchiolitis obliterans prognosis in children

INTRODUCTION

The prognosis of postinfectious bronchiolitis obliterans (PIBO) has many implications, ranging between reduced quality of life and life-threatening complications. We evaluated the prognostic factors for PIBO using the baseline clinical characteristics of patients and built a prediction model for determining the prognoses of PIBO patients using the identified parameters.

METHODS

We included 47 PIBO patients who underwent spirometry and impulse oscillometry and followed them up for at least 1 year. A patient's prognosis was classified as poor if the patient experienced at least one of the following: persistent respiratory symptoms for more than 1 year, two or more instances of hospitalizations due to respiratory symptoms, or more than one intensive care unit admission.

RESULTS

The prognoses of 32/47 (68.1%) patients was good, while that of 15/47 (31.9%) was poor. Spirometry results showed significantly lower forced vital capacity (FVC), forced expiratory volume in the first second (FEV₁ ), forced expiratory flow at 25%-75% of FVC, and post-bronchodilator (BD) FEV₁ values in the poor prognosis group; chest computed tomography (CT) demonstrated more inflammatory bronchiolitis findings. We created a nomogram for predicting prognoses using post-BD FEV₁ and inflammatory bronchiolitis on chest CT. The area under the curve for the nomogram was 84.6% (95% confidence interval: 72.8%-96.4%).

CONCLUSIONS

PIBO patients with lower pulmonary function values and more findings of inflammatory bronchiolitis on initial examination have poor prognoses. The nomogram for predicting PIBO prognosis is easy to use and can be applied at the time of diagnosis.

Postinfectious bronchiolitis obliterans masked by misdiagnosis as asthma

OBJECTIVES

Asthma and postinfectious bronchiolitis obliterans (PIBO) have similar clinical findings, and PIBO may be misdiagnosed with asthma. This study aimed to determine the clinical features of PIBO in children and the causes of delay in its diagnosis.

METHODS

We retrospectively evaluated all patients diagnosed with PIBO in four pediatric pulmonology centers between 2007 and 2018. In total, 64 PIBO patients were retrospectively reviewed. We compared the clinical and laboratory differences between PIBO patients who had initially been misdiagnosed with asthma and correctly diagnosed with PIBO.

RESULTS

Of the 64 patients, 22 (34.4%) had initially been misdiagnosed with asthma. Adenovirus was the most common infectious agent in children. The age upon diagnosis was older, and the symptom duration was significantly longer in patients misdiagnosed with asthma (P < .05). There were no statistical differences in terms of sex, history of prematurity, duration of hospitalization, treatment, history of oxygen or mechanical ventilation support, pulmonary function test (PFT) results and asthma-predisposing findings between the two groups (P > .05).

CONCLUSIONS

Patients with PIBO who had initially been misdiagnosed with asthma were correctly diagnosed at older ages and had longer symptom duration. Asthma may mask PIBO diagnosis by the similarity of symptoms and the clinical response to inhaled β2-agonist or steroid treatment. PFTs may not help clinicians because of the age of children. The delay in the diagnosis of PIBO is probably attributable to the fact that some clinicians fail to include PIBO in the differential diagnosis when there is no clinical response to asthma medication.

Postinfectious Bronchiolitis Obliterans in Children: Diagnostic Workup and Therapeutic Options: A Workshop Report

Bronchiolitis obliterans (BO) is a rare, chronic form of obstructive lung disease, often initiated with injury of the bronchiolar epithelium followed by an inflammatory response and progressive fibrosis of small airways resulting in nonuniform luminal obliteration or narrowing. The term BO comprises a group of diseases with different underlying etiologies, courses, and characteristics. Among the better recognized inciting stimuli leading to BO are airway pathogens such as adenovirus and mycoplasma, which, in a small percentage of infected children, will result in progressive fixed airflow obstruction, an entity referred to as postinfectious bronchiolitis obliterans (PIBO). The present knowledge on BO in general is reasonably well developed, in part because of the relatively high incidence in patients who have undergone lung transplantation or bone marrow transplant recipients who have had graft-versus-host disease in the posttransplant period. The cellular and molecular pathways involved in PIBO, while assumed to be similar, have not been adequately elucidated. Since 2016, an international consortium of experts with an interest in PIBO assembles on a regular basis in Geisenheim, Germany, to discuss key areas in PIBO which include diagnostic workup, treatment strategies, and research fields.

Quantitative CT and pulmonary function in children with post-infectious bronchiolitis obliterans

Objective

To investigate the feasibility of CT-based quantitative airway and air-trapping measurements and to assess their correlation with pulmonary function in children with post-infectious bronchiolitis obliterans (PIBO).

Materials and methods

This retrospective study approved by the institutional review board included chest CT scans and pulmonary function tests (PFT) completed between January 2005 and December 2016 in children diagnosed with PIBO. The quantitative analysis of segmental and subsegmental bronchi was performed on each chest CT scan, measuring the areas or diameters of lumens, walls, or the entire airway. The air-trapping volume (ATV), the volume of lung area exhibiting lower attenuation than the mean attenuation of normal and air-trapping areas, was also measured in each lobe. Comparison analyses between CT parameters and PFT results were performed with Pearson or Spearman correlation.

Results

In total, 23 patients were enrolled (mean age 7.0 ± 3.3 years; range, 4–15 years). We successfully measured 89.6% of all segmental bronchi. In the airway analysis, wall area showed a negative correlation with forced expiratory volume in one second (FEV₁) in the majority of the pulmonary lobes. Air-trapping analyses demonstrated that ATV was negatively correlated with FEV₁ and positively correlated with reactance at 5 Hz.

Conclusion

Quantitative airway and air-trapping measurements from chest CT are feasible and correlate with pulmonary function in pediatric PIBO patients.

Post-infectious bronchiolitis obliterans

Bronchiolitis obliterans is a rare and severe chronic lung disease resulting from a lower respiratory tract lesion. It may occur after a bone marrow or lung transplantation, infectious diseases, or less frequently after inhaling toxic substances or after connective tissue diseases. Pathology, pathogenesis, and molecular biology, as well as the best treatment of bronchiolitis obliterans, remain the subject of ongoing research. This review discusses our current knowledge of different areas of bronchiolitis obliterans associated with infectious lesions.

Lung Clearance Index and Quantitative Computed Tomography of Post-Infectious Bronchiolitis Obliterans in Infants

Post-infectious bronchiolitis obliterans (BO) could be diagnosed via spirometry and chest computed tomography (CT); however, these tests are limited in infants. We aimed to evaluate the utility of lung clearance index (LCI) and air-trapping lung volume from chest CT in infants. This prospective study included 20 infants (mean age, 10.9 ± 6.3 months) diagnosed with post-infectious BO between 2009 and 2016. All subjects underwent multiple breath washout tests. For quantitative analysis of chest CT, the mean lung area attenuation value was used as an individual cutoff to determine the air-trapping lung volume. The mean cutoff lung attenuation value was −659 Hounsfield units, the mean total lung volume was 265 ml, and the mean air-trapping lung volume percentage was 22.9%. Functional residual capacity correlated with total lung volume and normal attenuation lung volume (p < 0.02). LCI (p < 0.02) and moment ratio (MR) 1 (p < 0.05) correlated with the air-trapping lung volume percentage. The concordance indices of LCI (0.659, p = 0.025) and MR1 (0.642, p = 0.046) were significantly correlated with the air-trapping lung volume percentage from CT. LCI and quantitative air-trapping lung volume from chest CT are feasible, complimentary tools for assessing infants with post-infectious BO.

Clinical and follow-up study of bronchiolitis obliterans in pediatric patients in China

Bronchiolitis obliterans (BO) is in general a rare and life-threatening form of non-reversible obstructive lung disease in which the bronchioles are compressed and narrowed by fibrosis and/or inflammation. The purpose of this study was to evaluate the clinical features of BO in pediatric patients and explore its risk factors. The medical records of 35 pediatric patients with BO at Guangzhou Women and Children’s Medical Center were evaluated. The age at onset of symptoms was 2–42 months (mean 13.3 ± 8.9 months), with age at diagnosis of 5 months–4 years (mean 17.8 ± 9.0 months). High-resolution computed tomography findings included mosaic pattern (100%), atelectasis (37.1%), air trapping (31.4%), and bronchiectasis (20.0%). Three patients received lung biopsies and mainly exhibited an inflammatory process surrounding the lumen of bronchioles. BO predominantly resulted from post-infectious causes (91.4%) which were primarily caused by adenovirus (50%), followed by Mycoplasma pneumoniae (46.7%) and influenza (20%). Pulmonary function tests (PFTs) showed severe and fixed airflow obstruction, decreased compliance, and increased resistance. No significant difference was found between before and after steroid treatment ( P > 0.05). Two patients died owing to severe pulmonary complications, one of whom had inherent immunodeficiency. Our study suggests that the occurrence of BO, especially post-infectious BO, in China is relatively high and might result from primary immunodeficiency diseases in severe cases. Recurrent aspiration pneumonia caused by congenital dysplasia of the larynx and vaccination not on schedule might be potential risk factors for persistent and recurrent BO.