ABSTRACT
Background: Several studies have associated members of the KIR genes as susceptibility factors to inflammatory bowel diseases (IBD): ulcerative colitis (UC) and Crohn's disease (CD). Objectives: To assess the association between the presence and absence KIR genes and IBD susceptibility through a meta-analysis. Method: A systematic search was performed through the PubMed, Scopus, and Web of Science databases to obtain relevant articles published before March 2024. Associations between genes and susceptibility to IBDs were estimated by OR with 95 % CI. Results: We found positive associations of the KIR2DS1 and KIR2DS3 genes with susceptibility to UC, while the KIR2DL3 and KIR2DS4 full genes showed a negative association. In addition, the KIR2DS1, KIR2DS3, KIR2DS4, KIR2DS5, and KIR3DS1 genes showed a positive association with susceptibility to CD, whereas the KIR2DL1 gene showed a negative association. Conclusions: Our meta-analysis indicates that individuals carrying the KIR2DS1 and KIR2DS3 genes exhibit increased susceptibility to UC, whereas carriers of the KIR2DS1, KIR2DS3, KIR2DS4, KIR2DS5, and KIR3DS1 genes are more prone to CD. However, further studies are required to clarify the role of the KIR genes and their corresponding ligands in the pathology of IBD.