Developmental Changes in Immune Responses During Respiratory Syncytial Virus Bronchiolitis

Park, Hye Jin; Kim, So Yeon; Lee, Kye Hyang; Lee, Gyeong Hoon; Choi, Eun Jin; Kim, Jin Kyung; Kim, Woo Taek; Chung, Hai Lee

Abstract

PURPOSE: This study was performed to examine the developmental changes in the innate or adaptive immune responses in serum during naturally occurring acute respiratory syncytial virus (RSV) bronchiolitis.
METHODS
Forty-five children who were admitted with acute RSV bronchiolitis were enrolled. Two patient groups were defined: Group 1: young infants under 6 months of age; and Group 2: young children of less than 2 years of age. Immune responses in serum were determined in these two patient groups and compared with two age-matched control groups (Control 1 and 2), respectively. Serum samples were obtained on admission and analyzed for sCD14, a receptor for innate immune response, and the cytokines, IFN-gamma and IL-13 using ELISA.
RESULTS
Serum sCD14 levels were significantly higher but IFN-gamma and IL-13 levels were lower in control 2 compared with control 1. During RSV bronchiolitis, serum sCD14 increased significantly in both patient groups comparing each age-matched control group, which was even greater in group 2. IFN-gamma significantly increased in group 2, but showed a trend to decrease in group 1. IL-13 levels were significantly higher in group 2, but showed no significant difference in group 1 compared with age-matched controls.
CONCLUSION
Our study showed that innate immunity plays an important role in the pathophysiology of acute RSV bronchiolitis during early life and suggests that developmental changes in the innate and adaptive immunity may be considered in treatment of the disease.