ATG16L1 rs2241880/T300A increases susceptibility to perianal Crohn's disease: An updated meta-analysis on inflammatory bowel disease risk and clinical outcomes

BACKGROUND

ATG16L1 plays a fundamental role in the degradative intracellular pathway known as autophagy, being a mediator of inflammation and microbial homeostasis. The variant rs2241880 can diminish these capabilities, potentially contributing to inflammatory bowel disease (IBD) pathogenesis.

OBJECTIVES

To perform an updated meta-analysis on the association between ATG16L1 rs2241880 and IBD susceptibility by exploring the impact of age, ethnicity, and geography. Moreover, to investigate the association between rs2241880 and clinical features.

METHODS

Literature searches up until September 2022 across 7 electronic public databases were performed for all case-control studies on ATG16L1 rs2241880 and IBD. Pooled odds ratios (ORP ) and 95% CI were calculated under the random effects model.

RESULTS

Our analyses included a total of 30,606 IBD patients, comprising 21,270 Crohn's disease (CD) and 9336 ulcerative colitis (UC) patients, and 33,329 controls. ATG16L1 rs2241880 was significantly associated with CD susceptibility, where the A allele was protective (ORP : 0.74, 95% CI: 0.72-0.77, p-value: <0.001), while the G allele was a risk factor (ORP : 1.23, 95% CI: 1.09-1.39, p-value: 0.001), depending on the minor allele frequencies observed in this multi-ancestry study sample. rs2241880 was predominantly relevant in Caucasians from North America and Europe, and in Latin American populations. Importantly, CD patients harbouring the G allele were significantly more predisposed to perianal disease (ORP : 1.21, 95% CI: 1.07-1.38, p-value: 0.003).

CONCLUSIONS

ATG16L1 rs2241880 (G allele) is a consistent risk factor for IBD in Caucasian cohorts and influences clinical outcomes. As its role in non-Caucasian populations remains ambiguous, further studies in under-reported populations are necessary.

Investigation of ATG16L1 rs2241880 Polymorphism with Cancer Risk: A Meta-Analysis

Background and Objectives: Previous studies have investigated the impact of the ATG16L1 rs2241880 (Thr300Ala) polymorphism on individual susceptibility to cancer, but the conclusions are still controversial. To get a more precise evaluation of the correlation between ATG16L1 rs2241880 polymorphism and cancer susceptibility, we performed a meta-analysis of the association of all eligible studies. Materials and Methods: Searches were performed in the Web of Science, PubMed, Scopus and Google Scholar databases up to November 2018. A total of 12 case-control studies from 9 articles comprising 2254 cases and 4974 controls were included. Statistical analysis was achieved by STATA 14.1 and Review Manager 5.3 software. The odds ratios (ORs) with 95% confidence intervals (95% CIs) under five genetic models were used to determine the strength of association among rs2241880 polymorphism and cancer susceptibility. Results: The findings did not support an association between the rs2241880 variant in either the overall study population or the subgroups, based on cancer types and ethnicity in any of the genetic models. As far as we know, our study is the first meta-analysis of the association between rs2241880 polymorphism and cancer risk. Conclusions: In conclusion, the findings of this meta-analysis proposes that the ATG16L1 rs2241880 polymorphism may not play a role in cancer development. Further well-designed studies are necessary to clarify the precise role of the ATG16L1 rs2241880 polymorphism on cancer risk.