RANTES promoter gene polymorphisms and susceptibility to severe respiratory syncytial virus-induced bronchiolitis

Background: Severe respiratory syncytial virus (RSV) infection is characterized by enhanced chemokine activity. Several studies have linked increased regulated on activation, normal T cell expressed and secreted (RANTES) expression with severe RSV disease. Three single nucleotide polymorphisms, -28C/G, -403G/A, and In1.1T/C in the RANTES gene, have been correlated with the gene's transcriptional activity. In the present study, we explored the possible correlation of the genetic variability of the RANTES gene with the clinical manifestation of RSV disease. Methods: DNA samples were obtained from 106 children hospitalized for RSV bronchiolitis, in a 2-year period. One hundred twenty sex-matched healthy adults, without a history of severe lower respiratory tract infections, formed the control group. Results: No association was established between -28C/G polymorphism and RSV-induced bronchiolitis, mainly because of its extreme rarity in the studied population. No statistically significant differences were observed in cases and controls regarding genotype and allele frequencies of each of the In.1.1T/C and -403G/A polymorphisms. By contrast, the -28C/C-403G/AIn1.1T/T combined genotype was significantly more common in cases than in controls. Conclusions: Our results indicate an association between a common genotype with severe RSV infection. This observation supports the previously reported results indicating RANTES as an important mediator of RSV infection.