[Gene polymorphisms of Toll-like receptors in Chinese Han children with sepsis in Wenzhou]

Abstract

Objective: Sepsis remains a serious clinical problem because of high morbidity and mortality. The importance of Toll-like receptors (TLRs) for the induction of immune responses against sepsis was demonstrated in humans. The present study aimed to probe the gene polymorphisms of TLR4 (Asp299Gly and Thr399Ile) and TLR2 (Arg753Gln) in patients with sepsis among Chinese Han children in Wenzhou, and investigate the correlation with sepsis.

Method: This study was conducted as a case-control study. Using polymerase chain reaction and DNA sequencing, gene polymorphisms of TLR4 (Asp299Gly and Thr399Ile) and TLR2 (Arg753Gln) in 59 children with sepsis, 38 children with severe sepsis (including 20 septic shock) and 57 healthy controls were analyzed. Hardy-Weinberg method of statistics was used to compare the frequency of genotypes alleles among three groups.

Result: The mutant genotypes of TLR4 gene (Asp299Gly and Thr399Ile) were not found among sepsis, septic shock and control groups. In severe sepsis group, the Arg753Gln TLR2 polymorphism occurred in 2 out of 38 severe sepsis patients and both of the subjects with the TLR2 Arg753Gln polymorphism had fatal staphylococcal infections.

Conclusion: TLR4 gene (Asp299Gly and Thr399Ile) polymorphisms may not be correlated with susceptibility to sepsis among Chinese Han children in Wenzhou. The fact that only 2 out of 38 severe sepsis patients had Arg753Gln TLR2 polymorphism suggests that a larger sample size is needed because of the rarity of the TLR2 allele among Chinese Han children in Wenzhou.