Background: Linkage studies suggest a locus, SLEB2, involved in susceptibility to systemic lupus erythematosus (SLE) and programmed cell death 1 (PDCD1) gene locates in this region. The association of PDCD1 polymorphism (PD1.3A/G) with SLE has been widely investigated, but there are no unambiguous conclusions.
Objective: To assess the combined evidence for the association between PD1.3A/G polymorphism and SLE and to summarize the effect size of the polymorphism associated with susceptibility to SLE.
Methods: We surveyed studies on the PD1.3A/G polymorphism and SLE using comprehensive PubMed search up to May 2008. The pooled odds ratio (OR) was calculated using a fixed- or a random-effects model. Heterogeneity was identified by sensitivity analysis and publication bias was examined by funnel plot and Egger's test. We also computed the power for a given number of samples.
Results: A total of 20 datasets from eight studies that met our inclusion criteria were included. The studies comprised of a total of 2909 cases and 3995 controls. Stratified meta-analysis demonstrated a significant association between PD1.3A and SLE among non-Spanish European descents [OR, 1.290; 95% confidence interval (95% CI), 1.098-1.516; z = 3.10, P = 0.002], while PD1.3G is the risk allele in Spanish populations (OR = 1.414, 95% CI = 1.075-1.862; z = 2.48, P = 0.013). Both results have sufficient power to support these findings. No publication bias presented in the studies analysed.
Conclusions: This meta-analysis demonstrates a significant association between PD1.3A and SLE among non-Spanish European descents, while a negative association was observed in Spanish population.