Eosinophil cationic protein in infants with respiratory syncytial virus bronchiolitis: Predictive value for subsequent development of persistent wheezing

Infants with acute bronchiolitis during the first months of life are at inc reased risk of developing persistent wheezing and bronchial asthma later in life. The study of eosinophil cationic protein (ECP) suggests that eosinop hil-related inflammatory mechanisms may play a role in respiratory syncytia l virus (RSV) bronchiolitis. The aim of our study was to verify whether ser um ECP (s-ECP) measurements are useful in predicting the development of per sistent wheezing in children affected by RSV bronchiolitis during a 5 years follow-up period. Forty-eight infants were enrolled prospectively (mean ag e: 153.5 days). All had a clinical and radiological diagnosis of acute bron chiolitis and confirmed RSV infection. Peripheral eosinophil counts, levels of s-ECP, and serum IgE concentrations were measured during bronchiolitis. Five years later the children were re-evaluated in regard to their respira tory symptoms (standardized questionnaires) and atopic status (specific IgE levels). We observed significantly higher s-ECP levels (P < 0.001) at enrollment in subjects who developed persistent wheezing compared to subjects who did not show late wheezing. Initial s-ECP values allowed significant and correct p rediction of persistent wheezing (P < 0.001). The risk to develop respirato ry symptoms was 9.73 higher for infants with s-ECP levels greater than or e qual to 8 mug/L than for those with s-ECP levels <8 mug/L (P < 0.000). In conclusion, our study suggests that s-ECP levels in infants with bronchi olitis are useful in predicting the risk to develop wheezing in the subsequ ent 5 years. (C) 2001 Wiley-Liss, Inc.