Genetic association of PRKCD and CARD9 polymorphisms with Vogt-Koyanagi-Harada disease in the Chinese Han population.

BACKGROUND: Protein kinase C delta (PRKCD) and caspase recruitment domain family member 9 (CARD9) are genes involved in B and T cell activation, and cytokine production, which are vital mechanisms underlying autoimmune disease development. This study aimed to explore the association of the PRKCD and CARD9 genes with Vogt-Koyanagi-Harada disease (VKH) disease. The case-control study was performed to in 912 patients with VKH and 878 normal controls. MassARRAY system, SHEsis online platform, real-time PCR, and enzyme-linked immunosorbent assay were used to detect genotyping, haplotyping, mRNA expression, and cytokine levels, respectively. RESULTS: We found that rs74437127 C allele of PRKCD, rs3812555 CC genotype, and C allele of CARD9 were associated with increased susceptibility of VKH (Pc = 0.020, OR = 1.624; Pc = 2.04 × 10(-5), OR = 1.810; Pc = 2.76 × 10(-5), OR = 1.698, respectively). However, the rs74437127 T allele, and rs3812555 TC genotype and T allele were linked with decreased susceptibility to VKH (Pc = 0.020, OR = 0.616; Pc = 7.85 × 10(-5), OR = 0.559; Pc = 2.76 × 10(-5), OR = 0.589, respectively). PRKCD ATG and CARD9 GCTTA haplotypes decreased susceptibility to VKH (Pc = 3.11 × 10(-3), OR = 0.594; Pc = 5.00 × 10(-3), OR = 0.639, respectively). Functional studies on rs3812555 genotyped individuals revealed that CC carriers had significantly higher CARD9 mRNA expression and tumour necrosis factor-α production than TC/TT carriers (P = 1.00 × 10(-4); P = 2.00 × 10(-3), respectively). CONCLUSIONS: We found an association between PRKCD rs74437127 and CARD9 rs3812555 polymorphisms and VKH susceptibility and revealed that the increased susceptibility of rs3812555 for VKH may be mediated by regulating CARD9 gene expression and the production of pro-inflammatory cytokines, such as TNF-α.