The correlation between peripheral blood inflammatory factors,lung function levels,and TLR4 gene polymor-phisms in children with asthma

LIU Yang; WANG Shuang; LI Quan-lun; ZHANG Chao

doi:10.13820/j.cnki.gdyx.20230456

Abstract：Objective To investigate the correlations between Toll-like receptor 4(TLR4)gene polymorphism and inflammatory factors and lung function in children with asthma.Methods A total of 172 children with acute asthma attacks treated over the past three years were selected as the experimental group.Based on the severity of asthma attacks,the children were categorized into mild,moderate,severe,and critical levels.A control group consisting of 136 healthy children who underwent routine health examinations during the same period was selected.The lung function parameters(FEV1/FVC％)and fractional exhaled nitric oxide(FeNO)were measured in all subjects.Peripheral venous blood sam-ples were collected for ELISA analysis of interleukin-4(IL-4)and interferon-gamma(IFN-γ)expression levels.Additionally,eosinophil percentage(Eos)was determined using a hematology analyzer,total IgE was measured using a chemiluminescence immunoassay,and TLR4 gene polymorphisms(Asp299Gly and Thr399Ile)were detected using poly-merase chain reaction-restriction fragment length polymorphism(PCR-RFLP)analysis.The correlations between these gene polymorphisms and childhood asthma were analyzed.Results Levels of IL-4,Eos,IgE,and FeNO in the periph-eral blood of children with asthma were significantly higher in the experimental group than in the control group,while IFN-y levels and FEV1/FVC％were signifiicantly lower in the experimental group.There were no significant differences in TLR4 gene Asp299Gly genotypes or allele distributions between the experimental and control groups(P＞0.05).How-ever,there were significant differences in Thr399Ile genotypes and allele distributions(P＜0.05).The frequency of the T allele distribution was significantly higher in the experimental group.The TLR4 gene Thr399Ile polymorphism was not cor-related with peripheral blood Eos,IgE levels,or lung function indicator FEV1/FVC％in children with asthma.However,children with the Thr399Ile TT genotype exhibited higher levels of IL-4 and FeNO compared to those with the CC and CT genotypes,while IFN-γ levels were lower.Logistic regression analysis showed that children with the Thr399Ile TT geno-type had more severe asthma than those with the CC and TC genotypes.Binary logistic regression analysis revealed a corre-lation between TLR4 gene Thr399Ile polymorphism and childhood asthma severity.Conclusion TLR4 gene single nucle-otide polymorphisms are not associated with IgE,Eos,or lung function indicator FEV1/FVC％levels in children with asthma.However,they are associated with asthma severity and IL-4,IFN-γ,and FeNO levels.TLR4 and IL-4,IFN-γ may play a role in the progression of childhood asthma and could be key factors in the transition from mild to se-vere asthma.The TLR4 gene Thr399Ile polymorphism is significantly associated with childhood asthma.