HLA-DRB1 class II alleles in Indian asthmatic population: A candidate gene-environment interaction

IntroductionAsthma is a complex disease with interplay of genes and environment. Genome wide association studies (GWAS) have shown the systematic association of Human leukocyte antigen (HLA) genes with asthma. The objective of present study was to determine the frequency of HLA DRB1 alleles in adult Indian asthmatic and control groups.Material and methodsPolymerase Chain Reaction- sequence-specific typing (PCR-SSP) method was used for HLA genotyping in 98 healthy participants and 72 asthmatics.ResultsThe results revealed that DRB1*03 (OR = 2.63, 95% CI = 1.32-5.25), DRB1*04 (OR = 4.52, 95% CI = 1.06-22.02) and DRB1*07 (OR = 3.79, 95% CI = 1.03-15.10) were positively associated with risk of asthma while DRB1*15 (OR = 0.509, 95% CI = 0.257-1.01) were negatively associated with risk of asthma in Indian population. Association of low (> 150 IU/ml) and high (< 150 IU/ml) total serum immunoglobulin E, tIgE levels and HLA-DRB1 alleles in asthmatics showed no significant association.ConclusionOur results suggest that HLA-DRB1*03, DRB1*04 and DRB1*07 are involved with susceptibility of asthma, while DRB1*15 has protective effect in adult Indian asthmatics.