Bronchoalveolar lavage in infants with recurrent lower respiratory symptoms.

Kristiina Malmström,L Pekka Malmberg,Timo Paavonen,Marja‐Leena Majuri,Mika J Mäkelä,Seppo Sarna,Sejal Saglani,Harri Alenius,Merja Kajosaari,Harry Lindahl,Anna S Pelkonen,Maili Lehto

doi:10.1186/2045-7022-4-35

Abstract

BackgroundFew data are available about the inflammatory cytokine profile of bronchoalveolar lavage (BAL) from young children with frequent wheeze. The first aim was to investigate the BAL cellular and cytokine profiles in infants with recurrent lower respiratory symptoms in whom bronchoscopy was indicated for clinical symptom evaluation. The second aim was to relate the BAL results with the histological findings of the endobronchial carina biopsies.MethodsThirty-nine infants (median age 0.9 years) underwent lung function testing by whole-body plethysmography prior to the bronchoscopy. The BAL differential cell counts and cytokine levels were quantified. These findings were compared with the histological findings of the endobronchial carina biopsies.ResultsThe differential cytology reflected mainly that described for healthy infants with lymphocyte counts at the upper range level. A positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement membrane was found. Detectable levels of pro-inflammatory cytokine proteins IL-1β, IL-17A, IL-18, IL-23, and IL-33 were found, whereas levels of Th2-type cytokine proteins were low. Frequent wheeze was the only clinical characteristic significantly related to detectable combined pro-inflammatory cytokine profile. Lung function did not correlate with any cytokine.ConclusionsA positive association between BAL CD8+ lymphocytes and neutrophils and endobronchial reticular basement thickness was found. Detectable production of pro-inflammatory cytokines associated positively with frequent wheeze.

Highlights

Two characteristic pathological features of asthma, thickening of the reticular basement membrane and eosinophilic airway inflammation, are absent in symptomatic infants with reversible airflow obstruction [1] but already present in preschool children with severe, recurrent wheeze [2]
A network of antigen presenting dendritic cells and macrophages, bronchus associated lymphoid tissue structures, and Foxp3+ regulatory T cells have been detected in endobronchial biopsies already in these symptomatic infants [3]
The present study afforded us a unique opportunity to investigate the bronchoalveolar lavage (BAL) cellular and cytokine profiles in a group of infants with defined lung function [1] in whom bronchoscopy was indicated for clinical symptom evaluation

Summary

Introduction

Two characteristic pathological features of asthma, thickening of the reticular basement membrane and eosinophilic airway inflammation, are absent in symptomatic infants with reversible airflow obstruction [1] but already present in preschool children with severe, recurrent wheeze [2]. The present study afforded us a unique opportunity to investigate the BAL cellular and cytokine profiles in a group of infants with defined lung function [1] in whom bronchoscopy was indicated for clinical symptom evaluation. The BAL findings were compared with the histological findings of the endobronchial carina biopsies. Few data are available about the inflammatory cytokine profile of bronchoalveolar lavage (BAL) from young children with frequent wheeze. The first aim was to investigate the BAL cellular and cytokine profiles in infants with recurrent lower respiratory symptoms in whom bronchoscopy was indicated for clinical symptom evaluation. The second aim was to relate the BAL results with the histological findings of the endobronchial carina biopsies

Methods

Results

Conclusion