Effect of exogenous surfactant on Paediatric Bronchoalveolar lavage derived macrophages' cytokine secretion

Abstract

Background: Bronchoalveolar lavage is a useful bronchoscopy technique. However, studies in "normal" children populations are few. Furthermore, the anti-inflammatory effects of exogenous pulmonary surfactants on the bronchoalveolar cellular components are limited.

Methods: Thirty children, aged 3 to 14 years, underwent diagnostic bronchoscopy and bronchoalveolar lavage. Differential cytology, cytokine and chemokine measurements were performed on the fluid after exogenous surfactant exposure. The aim of the study was to investigate the potential anti-inflammatory effects of exogenous surfactants on the bronchoalveolar lavage fluid, specifically alveolar macrophages of healthy South African children.

Results: Alveolar macrophages were the predominant cellular population in normal children. Patients with inflammatory pneumonopathies had significantly more neutrophils. Levels of inflammatory cytokines were significantly lower after exogenous surfactant exposure. Moreover, IL-10 and IL-12 cytokine secretion increased after exogenous surfactant exposure.

Conclusion: This study provides the first data on bronchoalveolar lavage of healthy South African children. Bronchoalveolar lavage fluid from patients with pulmonary inflammation was characterised by neutrophilia. Finally, we propose that exogenous surfactant treatment could help alleviate inflammation in diseased states where it occurs in the tracheobronchial tree.

Keywords: Alveolar macrophages; Bronchoalveolar lavage; Bronchoscopy; Cytokines.

Fig. 1

H&E staining of human BAL sample after mononuclear cell isolation from patient diagnosed with asthma (a & b) and a healthy patient with an airway obstruction (c & d); Abbreviations: M: Macrophage, N: Neutrophil, Eos: Eosinophil, MD: Mucus debris. Scale bar represents: (a & b) 50 μm, (c) 100 μm, (d) 500 px