Bronchoalveolar lavage fluid in children: comparative proteomic analysis in infectious and non-infectious lung disease

To date, relatively few studies have been specifically designed to identify the proteome profile in pulmonary pediatric disease. The aim of this study was to survey proteins present in bronchoalveolar lavage fluid (BALf) of children affected by infectious or non-infectious lung conditions to investigate which proteins are potentially disease related. We enrolled 27 subjects (8.18 +/- 5.78 years) undergoing BAL. They were divided into: Group 1=infectious group (n=16) and Group 2=non-infectious group (n=11). Liquid chromatography-mass spectrometry/mass spectrometry proteomic analyses of BALf samples were performed. Fifty-four unique proteins, common to all subjects, were identified. In Group 1, the total protein number was lower than in Group 2, without reaching statistical significance. Except for the higher percentage of Hemoglobin_subunit_alpha and Ig alpha 2 chain C-region in Group 2 compared with Group 1 (P=0.05 and P=0.06, respectively), no other differences were noted. In the correspondence analysis, the main covariates distinguishing Group 2 included the presence of P1-P5-P19-P22-P23-P43-P46-P48, whereas Group 1 was characterized by the absence of P27-P29-P32-P37-P49-P52. No single protein specifically correlated with disease pathogenesis, but specific protein combinations may be useful in the detection of different pediatric pathological conditions.