APRIL polymorphism and systemic lupus erythematosus (SLE) susceptibility

Objective. Two novel non-synonymous polymorphisms of the APRIL gene, codon 67 (rs11552708) and 96 (rs3803800), were recently identified and tested for disease association. The 67G allele was reported to be associated with systemic lupus erythematosus (SLE) in a Japanese population. The aim of the study is to investigate whether the APRIL polymorphism associated with susceptibility to SLE in a Japanese population is associated with the susceptibility to SLE in other ethnic groups. Methods. Three hundred and forty-eight SLE patients (204 European-American, 103 African-American and 41 Hispanic) and 345 ethnicity-matched controls (201 European-American, 104 African-American and 40 Hispanic) were included from the Lupus Multiplex Registry and Repository (LMRR) and evaluated for genetic association. The APRIL codon 67 and codon 96 were genotyped by a 3-base extension method. Statistical evaluations were performed using both chi-square and logistic regression analysis. Results. Both the single-nucleotide polymorphisms (SNPs) were in Hardy-Weinberg equilibrium in cases and controls within each ethnic group. The APRIL codon 67 was significantly associated with SLE risk under the dominant model adjusted by ethnicity (odds ratio, 95% confidence interval and P -values were 1.45 and 1.02-2.06 and 0.036, respectively). Race-specific analysis also showed a trend for association in African-American and Hispanic SLE subjects. Conclusion. The APRIL codon G67R polymorphism associated with SLE in a Japanese population may also be associated with SLE in other populations.