Polymorphisms of FCRL3 in a Chinese population with Vogt-Koyanagi-Harada (VKH) syndrome

PURPOSE The polymorphisms of the Fc receptor-like 3 gene (FCRL3), a novel immunoregulatory gene, have been shown to be associated with certain autoimmune diseases. This study was designed to examine whether the polymorphisms of FCRL3 are associated with susceptibility to Vogt-Koyanagi-Harada (VKH) syndrome in a Chinese population. METHODS A case-control study was performed in 230 Chinese VKH patients and 301 healthy controls. Four single nucleotide polymorphisms (SNPs; -169C/T, -110A/G, +358C/G, and +1381A/G) in FCRL3 were detected using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). human leukocyte antigen -DR4 (HLA-DR4) and HLA-DRw53 genotyping was performed using PCR techniques. RESULTS The results showed that the frequency of haplotype CACG was significantly lower in patients when compared with that in controls (p=0.0018, corrected p [pc]=0.0288). A significantly higher frequency was found for haplotype CGGG in HLA-DR4 negative patients than in HLA-DR4 negative controls (p=9.94 x 10(-8), Pc=1.59 x 10(-6)). There were no significant differences in the allele and genotype frequencies of the four investigated SNPs between VKH patients and controls. HLA-DR4 and HLA-DRw53 were significantly associated with VKH syndrome (p=3.21 x 10(-16) and p=7.08 x 10(-5), respectively). Stratification analysis according to HLA-DR4 and HLA-DRw53 did not show any association of FCRL3 polymorphisms with VKH syndrome. CONCLUSIONS Our study confirms the previous association of HLA-DR4 and HLA-DRw53 with VKH syndrome but fails to demonstrate an association between FCRL3 polymorphisms and VKH syndrome. Haplotype CACG might be a protective haplotype for VKH syndrome, and haplotype CGGG may be a risk haplotype in HLA-DR4 negative individuals.