Toll-like receptor 4 gene polymorphism and giant cell arteritis susceptibility: a cumulative meta-analysis

Objective: Toll-like receptor (TLR) 4 (+896 A/G) gene polymorphism has been reported to be associated with susceptibility to giant cell arteritis (GCA) with inconsistent results. To provide a more definitive conclusion, a cumulative meta-analysis of the association of TLR4 (+896 A/G) polymorphism with GCA susceptibility combining previous studies was performed.

Methods: The cumulative meta-analysis included 3 case-control studies which provided a total of 437 patients and 1023 controls. Meta-analysis was conducted by fitting random effects models and checked for heterogeneity and publication bias. Combined odds ratio (OR) and associated 95% confidence intervals (CI) were obtained by using a DerSimonian and Laird random effects model.

Results: Three studies, all from a South European ancestry, were identified through a literature search and included in this meta-analysis. The cumulative meta-analysis showed that the pooled random effects OR was non significant (OR: 1.46, 95% CI: 0.95-2.25; p = 0.082). There is some evidence suggestive of moderate-high heterogeneity between the three studies, I2 34.2% (95% CI: 0-55.2).

Conclusion: This cumulative meta-analysis does not demonstrate an association of TLR4 (+896 A/G) gene polymorphism with susceptibility to GCA. Further studies using larger samples and in populations from different geographic origins are needed to determine the exact role of TLR4 gene polymorphisms in GCA.