Soluble Intercellular Adhesion Molecule-1 (sICAM-1) and Interferon-Gamma in bronchoalveolar lavage frluid from children with airway diseases

We have previously described that in bronchoalveolar lavage fluid (BALF), eosinophils characterize asthma and neutrophils are more prominent in infantile wheeze. In this study, we hypothesized that intercellular adhesion molecule 1 (ICAM-1) and interferon-gamma (IFN- γ ) would have a role in promoting migration of both cell types into the airway. To investigate this, we measured soluble (s) ICAM-1 in 68 BALFs from infants and young children with various respiratory problems. Children with asthma were characterized by significantly raised sICAM compared with those with chronic cough without wheeze (p = 0.05) or control subjects with no lower airway pathology (p = 0.045). The levels correlated with disease severity (evaluated with a symptom score) and with lymphocyte numbers. IFN- γ levels were also raised in children with asthma compared with those with chronic cough (p = 0.05), but there was no correlation with disease activity. Infantile wheeze was characterized by a linear correlation between sICAM-1 and IFN- γ (r = 0.55; p = 0.002). sICAM-1 levels in infantile wheeze correlated with the severity of the disease and lymphocyte numbers. IFN- γ levels were elevated in the wheezers treated with inhaled steroids compared with untreated infants (p = 0.03). Although sICAM-1 levels were increased in those with severe cough, no characteristic inflammatory profile was found in the group with chronic cough. Our study suggests that ICAM-1 and IFN- γ play a role in the activity of the inflammatory process in asthma in childhood and possibly in some infant wheezers, in whom IFN- γ may be one of the factors increasing the expression of ICAM-1. The role of IFN- γ , a T helper-1 cytokine, in children with asthma remains to be fully understood.