Analysis of TLR2, TLR4, and TLR9 single nucleotide polymorphisms in children with bacterial meningitis and their healthy family members

Abstract

Background: The aim was to analyse TLR2 rs5743708, TLR2 rs4696480, TLR4 rs4986790, TLR9 rs5743836, and TLR9 rs352140 single nucleotide polymorphisms (SNPs) in children with pneumococcal and meningococcal meningitis and their family members.

Methods: The study group consisted of 39 children with bacterial meningitis (25 with meningococcal meningitis and 14 with pneumococcal meningitis) and 49 family members. Laboratory test results and the course of the diseases were analyzed. Genomic DNA was extracted from 1.2ml of peripheral blood in order to analyze the five SNPs.

Results: Patients with pneumococcal and meningococcal meningitis showed a similar male/female ratio, mean age, and duration of symptoms. There were no statistically significant differences in biochemical markers between the two groups. All patients possessed at least one polymorphic variant of the analyzed SNPs. The most common SNP was TLR9 rs352140, detected in 89.7% of patients. No significant differences in SNP frequency were found between patients, family members, and the general population.

Conclusions: The allele frequencies in the population studied are in accordance with the literature data. The study did not find an association between the analyzed SNPs and susceptibility to bacterial meningitis. The role of SNPs in genes coding toll-like receptors and the interactions between them in controlling inflammation in the central nervous system needs further evaluation.

Keywords: Meningitis; Single nucleotide polymorphism; Toll-like receptor.