Exploring Associations of Lower Airway Lymphocytosis and Mucosal Cobblestone Appearance in Children Undergoing Flexible Bronchoscopy

Abstract

RATIONALE: Lower airway lymphocytosis and cobble-stoning are common findings in children undergoing flexible bronchoscopy (FB). However, to date there are no paediatric studies that have explored possible associations with these findings. Thus, using our dataset of 321 children, we explored possible associations between lymphocytosis found in the bronchoalveolar lavage (BAL) and cobblestoning of mucosa seen at FB. METHODS: Our database consisted of 321 children with BAL data; 100 were consecutive FB recordings retrospectively screened and 221 children prospectively collected (pooled from two separate studies). Univariable and multivariable logistic regression analysis were used to identify associations between BAL lymphocytosis (≥20%) and cobblestoning including presence of viruses (PCR), pathogenic bacteria (≥10E4 cfu/ml BAL) and airway eosinophilia (>1%). RESULTS: Lymphocytosis and mucosa cobblestoning were common, occurring in 70 (21.9%) and 129 (40.2%) children respectively. Multivariable analyses (Table 1) found that the presence of BAL lymphocytosis (≥20%) was significantly associated with the presence of cobblestones seen at FB. Notable absence of factors were bacteria and/or virus detection in the BAL. In the evaluation of factors associated with cobblestoning, the presence of BAL eosinophilia (>1%) reduced the likelihood of its presence. CONCLUSIONS: The association of lower airway mucosal cobblestoning with BAL lymphocytosis (≥20%) and its clinical implications requires further exploration.