BRONCH X ASTHMA X GENES

örmänen et al. [2] show that polymorphisms in toll-like receptor (TLR) 1 and TLR10 genes increased the risk of asthma in children who had bronchiolitis as infants. TLRs are cell membrane pattern proteins that recognise molecular patterns from microorganisms and they play an important role in regulating and activating immune responses to, for example, common respiratory viruses (Fig. 1). TLR1 and TLR10, together with TLR2 and TLR6, belong to the TLR2 subfamily of TLRs, and TLR10 is considered to be a primarily anti-inflammatory receptor. The birth cohort studied by Törmänen et al. consisted of children who were hospitalised for bronchiolitis when they were <6 months of age. The respiratory syncytial virus (RSV) caused 71% of the bronchiolitis cases and rhinoviruses caused 13%. In studies of the same cohort, the researchers previously reported that the TLR1rs5743618 polymorphism was associated with asthma at 1–6 years of age, while the TLR10rs4129009 polymorphism was associated with asthma at 5–7 years of age.