The SNP (rs11209026, Arg381Gln, R381Q) in the IL-23 receptor (IL23R) confers protection against multiple inflammatory diseases, representing one of the most significant human genetic polymorphisms in inflammatory diseases. We, therefore, investigated the association between IL-23 R R381Q gene polymorphism and asthma. This case-control study was performed on 209 patients, and 200 healthy controls. Using PCR-RFLP, the R381Q variant was screened in the IL-23R gene of the patients and controls. Serum IgE levels were measured using ELISA technique. Eosinophil absolute count was done with Sesmex cell counter. Our results indicated that the genotype and allele frequencies of the IL-23R R381Q polymorphism is significantly different between asthmatic patients and control subjects (p<0.001; odd ratio= 0.266; 95%, CI=0.118-0.604. Moreover, the asthmatic patients had higher eosinophil count and total serum IgE levels than controls as expected (p<0.001). The present study suggested that R381Q polymorphism in IL-23 receptor may be a predisposing allele for asthma.
Keywords: Asthma; IL-23 Receptor; Single Nucleotide Polymorphism.