Correlation between inflammatory mediators in the nasopharyngeal secretion and in the serum of children with lower respiratory tract infection caused by respiratory syncytial virus and disease severity.

OBJECTIVE To determine whether the concentrations of inflammatory mediators (CCL5, soluble intercellular adhesion molecule type 1 [sICAM-1], TNF-alpha, IL-6 and IL-10) in the nasopharyngeal secretion and in the serum of children with lower respiratory tract infection (LRTI) caused by respiratory syncytial virus (RSV) correlate with the clinical markers of disease severity. METHODS Between July of 2004 and December of 2005, 30 children less than three months of age, diagnosed with LRTI caused by RSV and admitted to a neonatal ICU, were included in this study. RESULTS The severity of disease at hospital admission, as determined with a modified clinical scoring system, presented a significant positive correlation with sICAM-1 and IL-10 concentrations in the nasopharyngeal secretion, as well as with IL-6 concentrations in the serum, of the patients. In addition, serum IL-6 concentrations presented a significant positive correlation with the duration of oxygen therapy and with the length of hospital stay. CONCLUSIONS At hospital admission, the concentrations of sICAM-1 and IL-10 in the nasopharyngeal secretion, as well as the concentration of IL-6 in the serum, could be used as markers of severity in patients with LRTI caused by RSV. The serum levels of IL-6 determined at admission could also be used to predict prolonged oxygen supplementation and hospital stay.