The role of TBXA2R, TGF-β1 and Il-18 gene polymorphisms in the pathogenesis of pollen induced allergic asthma- a case-control study from West Bengal, India

Background

Allergic asthma is a chronic inflammatory disease of the respiratory system's conducting airways affecting 330 million people globally and causes intermittent attacks of breathlessness, wheezing, airway hyper-reactivity and coughing when exposed to specific allergens. Thromboxane A2 receptor (TBXA2R), Transforming Growth Factor Beta 1 (TGF-β1) and Interleukin-18 (IL-18) genes are reported to be involved in inflammatory and immune response pathways related to asthma. Based on the above facts it can be hypothesized that single nucleotide polymorphisms (SNPs) in these genes may be associated with the asthma phenotype.

Objectives

The present study aims to analyze the role of the TBXA2R rs4523, TGF-β1 rs1800470, IL-18 rs1946519, IL-18 rs1946518 and IL-18 rs549908 gene polymorphism in asthma susceptibility among the population of West Bengal, India.

Results

Maximum number of patients showed sensitivity towards Azadirachta indica (73.46 %), followed by Cocos nucifera (72.27 %), Caesalpinia pulcherrima (65.17 %), etc. Significant difference in genotype and allele frequencies was obtained between the study groups for TBXA2R rs4523 and IL-18 rs1946519 polymorphisms. Asthma patients possessed significantly higher frequency of TBXA2R rs4523 CC and IL-18 rs1946519 TT genotypes than controls. TBXA2R rs4523 CC and IL-18 rs1946519 TT genotype bearing patients showed highest intensity of SPT reactions. Patients bearing rs4523 CC and rs1946519 TT genotypes had significantly higher FEV1/FVC ratio, total IgE level and blood Eosinophil count than heterozygous or major genotype bearers.

Conclusion

The present study concluded that TBXA2R rs4523 and IL-18 rs1946519 polymorphisms are associated with allergic asthma susceptibility in the population of West Bengal, India.