Postinfectious bronchiolitis obliterans in children: lessons from bronchiolitis obliterans after lung transplantation and hematopoietic stem cell transplantation

Abstract

Postinfectious bronchiolitis obliterans (PIBO) is an irreversible obstructive lung disease characterized by subepithelial inflammation and fibrotic narrowing of the bronchioles after lower respiratory tract infection during childhood, especially early childhood. Although diagnosis of PIBO should be confirmed by histopathology, it is generally based on history and clinical findings. Irreversible airway obstruction is demonstrated by decreased forced expiratory volume in 1 second with an absent bronchodilator response, and by mosaic perfusion, air trapping, and/or bronchiectasis on computed tomography images. However, lung function tests using spirometry are not feasible in young children, and most cases of PIBO develop during early childhood. Further studies focused on obtaining serial measurements of lung function in infants and toddlers with a risk of bronchiolitis obliterans (BO) after lower respiratory tract infection are therefore needed. Although an optimal treatment for PIBO has not been established, corticosteroids have been used to target the inflammatory component. Other treatment modalities for BO after lung transplantation or hematopoietic stem cell transplantation have been studied in clinical trials, and the results can be extrapolated for the treatment of PIBO. Lung transplantation remains the final option for children with PIBO who have progressed to end-stage lung disease.

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

“…BO is thought to be caused by an initial insult to the lower airways [6]. However, there are three separate clinical entities of BO.…”

“…rough an orchestrated interaction, the airway epithelial damage, rather than repairing it in a normal fashion with a normal epithelial layer, is largely replaced by T cells and neutrophils, with subsequent matrix degradation, collagen deposition, and fibroblast stimulation, ultimately leading to the airway fibrosis characteristic of BO [6]. e lack of a good animal model of PIBO hampers the efforts to determine which of the many potential biomarkers would serve as a reasonable potential target in human trials.…”

Bronchiolitis obliterans after severe adenovirus pneumonia:a review of 46 cases

“…After adenovirus infection, epithelial cells were damaged and necrotic, replaced by T cells and neutrophils, followed by matrix degradation, collagen deposition and broblast stimulation, resulting in brosis of airway BO (8) .Studies have shown that glucocorticoids can inhibit in ammatory response and slow down the process of brosis (9) , being part and parcel in the treatment of BO. There is no clear conclusion about the duration of in ammation in patients with BO.…”

Comparative analysis of morphological and molecular motifs in bronchiolitis obliterans and alveolar fibroelastosis after lung and stem cell transplantation

“…Fibroelastotic remodelling of the small airways and alveoli has been recognised as a rather non-specific correlate of pulmonary injury and remodelling for over a century [13,15,18,19,32,33]. The actual categorisation of these changes and the allocation of histopathological patterns to specific disease entities, particularly in the field of transplantation, have started far more recently.…”