IL-6 174 G/C Polymorphism in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

  • Danyal Imani Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
  • Ramazan Rezaei Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
  • Davood Jafari Department of Immunology, School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
  • Bahman Razi Department of Hematology, School of Paramedicine, Tehran University of Medical Sciences, Tehran, Iran.
  • Shahab Alizadeh Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
  • Mohammad Bashashati Network of Immunity in Infection, Malignancy, and Autoimmunity (NIIMA), Universal Scientific Education and Research Network (USERN), El Paso, TX, USA.
  • Nima Rezaei Department of Immunology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. AND Research Center for Immunodeficiencies, Children's Medical Center, Tehran University of Medical Sciences, Tehran, Iran. AND Systematic Review and Meta-Analysis Expert Group (SRMEG), Universal Scientific Education and Research Network (USERN), Tehran, Iran.
Keywords: Interleukin-6, Polymorphism, Inflammatory bowel disease, Meta-analysis


The results of previous studies on the association between IL-6-174G/C (rs1800795) polymorphism and inflammatory bowel disease (IBD), including Crohn’s disease (CD) and ulcerative colitis (UC) are not consistent. The present meta-analysis has pooled all eligible studies to understand the relation between this gene polymorphism and IBD risk. A structured search of Medline, EMBASE, and Scopus databases were performed to identify all eligible studies published before June 2017. Odds ratio (OR) and 95% confidence intervals (CIs) were assessed applying fixed- or random-effect models to evaluate the strength of association in recessive model, dominant model, allelic model, heterozygote contrast, and homozygotes contrast. A sum of 9 articles with 1524 IBD cases and 1586 healthy subjects were included in this study. No significant association between the IL-6 -174 G/C polymorphism and overall IBD susceptibility in any tested genetic model was found. Moreover, in the subgroup analysis based on subtypes, the associations between the IL-6 174-G/C polymorphism and CD and UC missed statistical significance. The current meta-analysis suggests that the IL-6-174 G/C polymorphism is not associated with IBD susceptibility. Further and comprehensive studies are necessary to warrant this result.


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How to Cite
Imani D, Rezaei R, Jafari D, Razi B, Alizadeh S, Bashashati M, Rezaei N. IL-6 174 G/C Polymorphism in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis. Acta Med Iran. 56(12):740-749.
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