Serum eosinophil cationic protein and CD23 in acute RSV bronchiolitis.

Background: Elevated concentrations of eosinophil cationic protein (ECP) have been found in acute viral wheezing during infancy. Furthermore, RSV infection has been suggested to stimulate type-2 cytokine responses. The aim of this study was to test whether serum ECP and soluble CD23 levels, which are markers of eosinophil and IgE responses, respectively, are elevated in infants hospitalized for acute respiratory syncytial virus (RSV) bronchiolitis.