Toll-like receptor 2 subfamily genotypes are not associated with severity of bronchiolitis or postbronchiolitis wheezing in infants.

AIM: Expression of toll-like receptor (TLR) 2 subfamily genes, including genes encoding TLR1, TLR2, TLR6 and TLR10, have been connected to allergy and asthma. This controlled study investigated the association of TLR1, TLR2 and TLR6 gene polymorphisms with clinical characteristics and subsequent wheezing in young infants with bronchiolitis.

METHODS

In all, 129 full-term infants hospitalised for bronchiolitis at the age of <6 months were clinically followed up until a mean age of 18 months. Genotyping of the TLR1 T1805G, TLR2 G2258A and TLR6 C745T polymorphisms was carried out by pyrosequencing and in 318 healthy, Finnish controls.

RESULTS

There were no significant associations between TLR1, TLR2 or TLR6 genotypes and severity of bronchiolitis or risk of postbronchiolitis wheezing. TLR6 polymorphism was associated with allergy in univariate analyses. Minor allele frequency (MAF) in the TLR1 gene (17%) in the hospitalised children was similar to our Finnish controls, but different to European controls from other studies. MAF in the TLR6 gene was 50% versus 41% in both the Finnish and European controls. MAF in the TLR2 gene was low (3%) in study subjects and in both controls.

CONCLUSION

TLR2 subfamily gene polymorphisms were not associated with severity of bronchiolitis or risk of postbronchiolitis wheezing.