Objective: To explore the association of interleukin 8 (IL-8)-251T/A and 781 C/T single nucleotide polymorphisms (SNPs) with the susceptibility of infants and young children to respiratory syncytial virus (RSV) infection.
Method: This study included 101 hospitalized patients under 2 years of age who suffered from RSV pneumonia, 108 hospitalized patients under 2 years of age with non-RSV pneumonia and 35 core families with a child hospitalized for RSV pneumonia. Genotypes of 2 SNP loci in all enrolled persons were defined by allele specific polymerase chain reaction (AS-PCR), and confirmed by gene sequencing. The allele's frequencies of SNPs were analyzed with case-control study and transmission disequilibrium test (TDT), linkage of 2 loci and haplotypes composed of the 2 loci were also studied.
Results: (1) The frequency of IL-8-251T in cases was dramatically high (OR = 2.08, P = 0.0002, case-control study; LRT = 14.31, P = 0.0008, TDT). (2) IL-8-251T and 781C was linkaged (D' = 0.607 +/- 0.03, r(2) = 0.2861, P = 0.0000). (3) Haplotype of TC was significantly high in cases (P = 0.01).
Conclusion: These findings support that haplotype of TC composed of IL-8-251T and 781C is associated with the susceptibility to RSV, namely, some RSV predisposing genes are located in the gene fragment including TC haplotype or linked tightly with this gene fragment.