Post-bronchiolitis wheezing is associated with toll-like receptor 9 rs187084 gene polymorphism

Abstract

Innate immunity receptors play a critical role in host defence, as well as in allergy and asthma. The aim of this exploratory study was to evaluate whether there are associations between TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and viral findings, clinical characteristics or subsequent wheezing in infants with bronchiolitis. In all, 135 full-term infants were hospitalized for bronchiolitis at age less than 6 months: 129 of them were followed-up until the age of 1.5 years. The outcome measures were repeated wheezing, use of inhaled corticosteroids, atopic dermatitis during the first 1.5 years of life and total serum immunoglobulin E (IgE). There were no significant associations between the genotypes or allele frequencies of TLR7 rs179008, TLR8 rs2407992, TLR9 rs187084 or TLR10 rs4129009 polymorphisms and clinical characteristics or the severity of bronchiolitis during hospitalization. During follow-up, repeated wheezing was more common in children with TLR9 rs187084 variant genotype CC (30.5%) than in children with TLR9 wild-type genotype TT (12.2%) (p = 0.02, aOR 2.73, 95% CI 1.02–7.29). The TLR10 rs4129009 minor allele G was associated with elevated total serum IgE. TLR9 rs187084 gene polymorphism may be associated with post-bronchiolitis wheezing, and TLR10 rs4129009 gene polymorphism may be associated with atopy.

Toll‐like receptor 1 and 10 variations increase asthma risk and review highlights further research directions

“…The TLR3 rs3775291 variant genotype was associated with the risk of being hospitalised for bronchiolitis , but the wild genotype was associated with repeated post‐bronchiolitis wheezing . The variant TLR9 rs187084 genotype was associated with repeated wheezing during the 12‐month post‐bronchiolitis follow‐up , but the other eight TLR gene variations that were studied did not show such associations .…”

“…Blood samples for genetic studies were obtained at the control visit at 1.5 years and supplemented at the 5–7 year visit if needed, and deoxyribonucleic acid was isolated, frozen and studied later. Finally, data were available for the polymorphisms of the genes encoding all the TLRs 1–10 .…”

“…Reduced lung function, which manifested as either increased resistance or decreased reactance in impulse oscillometry, was present in 20% of the children at 5–7 years of age . Table summarises the clinical and lung function findings in relation to the 10 TLR single nucleotide polymorphisms (SNPs) in the children in the Finnish bronchiolitis cohort. This covers their initial hospitalisation for bronchiolitis and the follow‐ups at 1.5 and 5–7 years of age.…”

RSV‐hRV co‐infection is a risk factor for recurrent bronchial obstruction and early sensitization 3 years after bronchiolitis

“…It is difficult to compare our results regarding allergic sensitization with those of other published works. For Nuolirvita et al, current atopy is considered if the child has either allergic rhinitis or atopic dermatitis. Other authors base the diagnosis of atopy on skin prick tests with or without association with physician diagnosis of allergy …”

Disease severity in respiratory syncytial virus infection: Role of host genetic variation

“…Another group, through genotyping of 19 polymorphisms in the autosomal TLRs, found weak association of one TLR9 promoter polymorphism (rs5743836) and TLR10 haplotypes with RSV infection . Furthermore, Nuolivirta et al found that TLR9 rs187084 polymorphism may be associated with postbronchiolitis wheezing, while the TLR10 rs4129009 polymorphism may be associated with atopy . Taken altogether, these reports help to identify at risk infants and to develop therapeutics of this potentially fatal infection.…”