FCGR2A rs1801274 polymorphism is associated with risk of childhood-onset idiopathic (immune) thrombocytopenic purpura: Evidence from a meta-analysis

Introduction

Previous studies have evaluated the association between FCGR2A H131R (rs1801274) polymorphism and idiopathic (immune) thrombocytopenic purpura (ITP), but results remain inconsistent. This meta-analysis was conducted to clarify these controversies.

Methods

Literatures on PubMed/ Medline, Embase and CENTRAL databases up to September 2013 were searched by two investigators. The distributions of alleles and genotypes between cases and controls were compared by using odds ratios (ORs) and 95% confidence intervals (95% CIs). Fixed or Random-effects models were used when appropriate.

Results

10 studies involving 553 patients and 1088 controls were available for this study, including 7 studies of Caucasian descendents, 2 studies of Asian descendents, and 1 study contained diverse ethnicity. In this studied overall population, we didn’t found any significant association between the FCGR H131R polymorphism and the risk of ITP for all genetic models. But in the subgroup analysis, a significant association between FCGR H131R polymorphism and ITP susceptibility was observed in Caucasian population of childhood-onset group for H vs. R (OR = 1.246, 95% CI 1.021-1.522, p = 0.031), HH vs. HR + RR (OR = 1.562, 95% CI 1.145-2.129, p = 0.005), HH vs. HR (OR = 1.598, 95% CI 1.146-2.228, p = 0.006), HH vs. RR (OR = 1.484, 95% CI 1.005-2.191, p = 0.047). No significantly between-study heterogeneity was observed for all genotype models in Caucasian childhood-onset ITP subtype analysis. However, this association was not stable after sensitivity analysis.

Conclusion

Our present meta-analysis indicated that FCGR H131R polymorphism might not be associated with risk of ITP in overall population. However, in Caucasian childhood-onset subgroup, there might be an association between FCGR2A H131R polymorphism and ITP risk, which is not robust and should be explained with caution.