The relationship between the rs4986791 variant of the TLR4 gene and the severity of bronchial asthma in children.

Background: Toll-like receptor 4 (TLR4) is an important receptor for lipopolysaccharide and lipid A, components of gram-negative bacteria. At present, a variant in TLR4 has been shown to be associated with asthma, but it has not been reported whether variants in TLR4 are associated with bronchial asthma in children.

Objective: The objective is to determine the relationship between the rs4986791 (+1196C/T) variants of TLR4 and bronchial asthma in Chinese children.

Methods: DNA extracted from peripheral blood samples was amplified and the Bi-PASA technique was carried out to identify the genotypes in 600 patients.

Results: The result showed no difference between the 1196 C/T variant of TLR4 and hemoglobin level, proportion of neutrophils and lymphocytes, leukocyte, basophil and eosinophil counts, log10IgE and hsCRP in the peripheral blood of bronchial asthmatic patients. However, the eosinophil ratio, FEV1% and FEV1/FVC level of asthma patients with the CT genotype was lower than those of patients with the CC genotype, which were 1.19 ± 0.10 and 1.67 ± 0.18 (P = 0.01), 81.25 ± 0.50 and 84.99 ± 0.65 (P < 0.0001), 81.72 ± 0.568 and 5.55 ± 0.78 (P < 0.0001), respectively. The incidence of bronchial asthma in patients with the CT genotype is higher than that in patients with the CC genotype. We analysed the influence of the two genotypes on the current medical history by multiple logistic regression, performing a comparative analysis between the two genotypes and bronchial asthma (P < 0.05). Patients with moderately persistent asthma with the CT genotype are more likely to develop severely persistent asthma compared to those with the CC genotype (P < 0.01).

Conclusions: This comparative analysis between rs4986791 and bronchial asthma in children indicates that this variant is associated with bronchial asthma risk in Chinese children.