The Role of Pulmonary Genetic Variations in the Pathogenesis of Pediatric Postinfectious Bronchiolitis Obliterans.

Objective: Postinfectious bronchiolitis obliterans (PIBO) is a chronic airway disease. The severity of the damage and the subsequent obstructive and inflammatory processes varies from one individual to another. The objective was to identify genetic variations that may be associated with pulmonary diseases in patients with PIBO.

Material and methods: This retrospective descriptive study was carried out to define potential genetic changes that may be associated with PIBO. Medical records were used to obtain sociodemographic characteristics. Neutrophil, lymphocyte, platelet counts, immunoglobulins and C-reactive protein values, thoracic computed tomography (CT) findings and genetic analysis results for pulmonary panel using next-generation sequencing technology were recorded.

Results: Sixteen patients were enrolled. Median age at diagnosis was 27.5 months (range: 7-195 months). Wheezing was the most common presenting symptom. The most prevalent finding on thoracic CT was a mosaic pattern. In all but one, a wide range of variations genes related to both pulmonary structure and function were identified. The genes identified included those related to primary ciliary dyskinesia (DNAH genes), surfactant metabolism disorder (ABCA3, CSF2RB), pulmonary fibrosis (MUC5B, SFTP), and bronchiectasis (SCNN1B).

Conclusion: Heterozygous variations associated with pulmonary diseases, including the MUC5B and DNAH genes, and CSF2RB, were identified in most patients diagnosed with PIBO, which may have clinical significance. These data are valuable in hypothesis formation that may lead to the evaluation of these three genes in the pathogenesis of PIBO in children.