association of interferon-gamma gene polymorphism (+874 a/t) and oral lichen planus susceptibility: systematic review and meta-analysis

Background and objectives: most studies have identified interferongamma (ifn gamma;) as a key role in the pathogenesis of oral lichen planus (olp). recent studies have also shown a link between ifn gamma; (+874 a/t) gene polymorphism and olp. the purpose of the present metaanalysis is to investigate the relationship between ifn gamma; (+874 a/t) gene polymorphism and susceptibility to olp.methods: a systematic search of resources to investigate the association between ifn gamma; and olp from google scholar, pubmed, embase, cochrane, scopus, proquest, ovid and web of science (from 2000 to april 2019) completed. two individuals independently assessed the quality of the articles. endnote x5 resource management software was used to organize, study titles and abstracts as well as identify duplicates. a random effect model was also used to perform the metaanalysis.results: four ifn gamma; (+874 a/t) polymorphism studies with 297 patients in the case group and 621 healthy controls in the 4 different countries were included. after metaanalysis, a significant association was found between ifn gamma; polymorphism (+874 a/t) and olp. (t vs a: odds ratio (or) = 1.62; 95% ci = 1.282.04; tt vs aa: or = 2.67; 95% ci = 1.6 4.45; at vs aa: or = 1.56; 95% ci = 1.6 4.45; tt vs at + aa: or = 1.73; 95% ci = 1.132.64; at + tt vs aa: or = 1.75; 95% ci = 1.282.43)conclusion: based on this metaanalysis, there was a positive relationship between ifn gamma; (+874 a/t) gene polymorphism and the risk of olp. the findings showed that increasing tt genotypes significantly increased susceptibility to olp in comparison with other genotypes.