Our findings provide some evidence that SNPs in CCL5 and NOS2 are associated with presence of bronchiolitis and SNPs in TLR4, TLR2, TLR9, VDR and CCL5 are associated with severity of bronchiolitis.
This study shows for the first time that the fusion (F) protein of respiratory syncytial virus (RSV), a major cause of bronchiolitis and death, particularly in infants and young children, physically interacts with the Toll-like receptor 4 (TLR4) coreceptor, MD-2, through its N-terminal domain.
No TLR4 mutations were found.The frequencies of both the CC genotype and the C allele of CD14 -550 C/T were significantly higher in children with RSV bronchiolitis than in the control subjects.
The presence of TLR4 mutations (Asp299Gly and Thr399Ile) were associated with severe RSV bronchiolitis and were significantly over-represented in groups II and III.
These findings suggest that TLR4 mutations, but not the CD14/-159 polymorphism, are associated with an increased risk of severe RSV bronchiolitis in previously healthy infants.