RANTES may be predictive of later recurrent wheezing after respiratory syncytial virus bronchiolitis in infants

Background: In vitro studies have shown that RANTES is strongly induced by respiratory syncytial virus (RSV) infection in cultures of upper airway epithelial cells. RANTES is known as a chemoattractant and activator for eosinophils. Objectives: We performed this study to investigate whether RANTES is increased in the airway during naturally acquired RSV bronchiolitis. RANTES levels were then evaluated in relation to the severity of illness and later development of recurrent wheezing. Methods: We measured RANTES in nasal secretions of 30 patients with acute RSV bronchiolitis. Eosinophil cationic protein (ECP) was determined to evaluate the activation of eosinophils. The severity of illness was determined by the initial PaO2 values and the duration of wheezing. At a 1-year followup, all infants were re-evaluated if they had experienced subsequent wheezing, and we investigated if RANTES levels could predict the later development of recurrent wheezing. Results: Both RANTES and ECP in RSV bronchiolitis were significantly higher than in controls. There was a significant correlation between the levels of RANTES and ECP. RANTES was not significantly higher in patients with severe symptoms than in patients with mild symptoms. RANTES in infants who had experienced subsequent wheezing was significantly higher than in infants who had not. Conclusions: Our results showed that RANTES is increased in nasal secretion during acute RSV bronchiolitis and suggest that high levels of RANTES may be predictive of later development of recurrent wheezing.