Association of interleukin genes polymorphism with asthma susceptibility in Indian children: a case-control study

Background: Interleukins (IL) 4 and 13 genes and their receptors (R) are the key cytokines which amplify inflammatory reactions in asthma. Objective: This study aimed to investigate the association of IL 4, 4R, 13 and 13 R genes polymorphism with asthma in Indian children. Methods: In this hospital-based case-control study, included were children aged 1-15 years recruited as diagnosed cases of bronchial asthma, according to EPR 2007 and excluded were subjects with other respiratory diseases. Children with no present or past history of asthma were enrolled as controls. Spirometry was done in cases age >= 6 years. Gene-gene interaction was evaluated using binary logistic regression. Results: From October 2010 to July 2013, 275 cases and 275 controls were recruited. Gene-gene interactions between C1112T in IL 13 and Ile50Val in IL 4 R gene polymorphisms were found to be statistically significant (OR = 2.37, 95% CI = 1.04-5.42, p = 0.040). Individuals with CT and GG genotype of C1112T in IL 13 and Ile50Val in IL 4 R were at twice the risk for the development of asthma compared to individuals with both non-risk genotypes. Conclusion: The data suggests that gene-gene interactions between IL 13 and IL 4 R genes may play an important role in asthma among Indian children.