Class II transactivator (CIITA) is a master regulator of MHC gene expression and plays a role in inducing the expression of other immune system genes, including IL‐4, IL‐10 and Fas ligand, as well as more than 60 other immunologically significant genes. We used CIITA as a candidate gene to analyse whether any single‐nucleotide polymorphisms (SNPs) are associated with chronic hepatitis B virus (HBV) infection. In total, 773 patients with chronic HBV infection were enrolled in this hospital‐based case–control study. The patients were divided into groups according to their clinical characteristics: 596 patients had chronic hepatitis B (CHB), and 177 patients had hepatocellular carcinoma (HCC). A total of 313 patients with self‐limited HBV infection were selected as the control group. CIITA gene variants were screened using Haploview 4.2 software; improved multiplex ligation detection reaction technology was then used for genotype detection, and HaploReg v4.1 was employed to predict the functions of 15 variants. The results showed that SNPs in introns in the CIITA gene, namely, rs13333382 (TT + TA vs. AA: p = .003, odds ratio (OR) = 0.65, 95% confidence interval (CI) = 0.49–0.87) and rs4780335 (CC + CG vs. GG: p = 9.40 × 10−5, OR = 0.55, 95% CI = 0.41–0.74), were positively associated with self‐limited HBV infection in the dominant genetic model. Additionally, SNP rs1139564 (TT + TC vs. CC: p = .002, OR = 1.61, 95% CI = 1.19–2.16) in the 3' untranslated region may increase the risk of CHB. According to in silico analysis, all three statistically significant variants act as transcription factor binding motifs. However, we did not find that these 15 mutations are associated with HCC risk. Therefore, we believe that CIITA is a susceptibility gene for CHB rather than for HCC.

中文翻译：

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II类反式激活因子的遗传变异与汉族人群的慢性乙型肝炎病毒感染有关

II 类反式激活因子 (CIITA) 是 MHC 基因表达的主要调节因子，在诱导其他免疫系统基因的表达中发挥作用，包括 IL-4、IL-10 和 Fas 配体，以及 60 多种其他免疫学重要基因. 我们使用 CIITA 作为候选基因来分析是否有任何单核苷酸多态性 (SNP) 与慢性乙型肝炎病毒 (HBV) 感染相关。总共有 773 名慢性 HBV 感染患者参加了这项基于医院的病例对照研究。根据临床特征将患者分组：慢性乙型肝炎（CHB）596例，肝细胞癌（HCC）177例。共选择 313 例自限性 HBV 感染患者作为对照组。CIITA基因变异使用Haploview 4.2软件进行筛选；然后采用改进的多重连接检测反应技术进行基因型检测，并采用HaploReg v4.1预测15个变异体的功能。结果表明，CIITA 基因内含子中的 SNP，即 rs13333382（TT + TA vs. AA：p = .003，优势比 (OR) = 0.65，95% 置信区间 (CI) = 0.49–0.87）和 rs4780335 （CC + CG 与 GG：p = 9.40 × 10−5，OR = 0.55，95% CI = 0.41–0.74），在显性遗传模型中与自限性 HBV 感染呈正相关。此外，3' 非翻译区的 SNP rs1139564（TT + TC vs. CC：p = .002，OR = 1.61，95% CI = 1.19–2.16）可能会增加 CHB 的风险。根据计算机分析，所有三个具有统计学意义的变体都充当转录因子结合基序。然而，我们没有发现这 15 个突变与 HCC 风险相关。