中国西南三地HCV基因型的分布及临床特征

Distribution and clinical features of HCV genotypes in three areas in southwest China

摘要:

目的  了解丙型肝炎病毒（HCV）基因型在四川（川）、云南（滇）、贵州（黔）等中国西南地区汉族丙型肝炎患者中的分布及临床特征，为丙型肝炎的防治提供依据。方法  对221例来自川、滇、黔地区的丙型肝炎患者，采用焦磷酸测序法进行HCV基因分型并分析不同基因型丙型肝炎致病性的差异。结果  ①216例HCV-
RNA阳性的丙肝患者被成功分型，共发现1、2、3、6等4种常见基因型和1a、1b、2a、2b、3a、3b、6a等7种常见基因亚型，其所占比例为：1a型5.1%（11/216）、1b型36.1%（78/216）、2a型3.7%（8/216）、2b型0.9 %（2/216）、3a型7.4%（16/216）、3b型27.8%（60/216）、6a型17.1%（37/216），此外，还发现其他少见亚型（4a/6n）共4例，占1.9%（4/216）。②川、滇、黔分布前3位的基因亚型分别是3b、1b、6a和3b、1b、2a/3a及1b、6a、3b；男、女患者比例最高的亚型分别是3b（33.1%）和1b（48.3%）；>40岁患者以1b（39.8%）、3b（18.6%）、6a（15.9%）为主；<40岁患者以3b（37.9%）、1b（32.1%）、6a（18.4%）为主；感染方式以输血（血制品）40.1%为主，其他及不明原因者也占较大比例（33.8%）。③急性丙型肝炎、慢性丙型肝炎、丙肝后肝硬化和肝癌4种临床类型的丙型肝炎均以1b型比例最高，其次是3b、6a型；1b型患者的HCV载量及肝功能损害指标均高于其他亚型患者（P <0.05）。结论  川、滇、黔等中国西南部地区HCV-RNA阳性的汉族HCV感染者以1b、3b、6a为优势基因，且呈多样化分布；HCV载量较高的1b亚型，可能更容易导致患者肝功能的损害以及丙型肝炎的慢性化、肝脏的纤维化和癌变。

Abstract:

Objective To study the distribution of hepatitis C virus (HCV) genotypes in the hepatitis C patients of Han nationality in Sichuan, Yunnan and Guizhou so as to provide evidence for prevention and treatment of hepatitis C. Methods HCV in 221 patients were detected by pyrophosphate sequencing method for genotyping, then the differences in pathogenicity of HCV with different genotypes were compared. Results In the 216 HCV-RNA positive patients from Sichuan, Yunnan and Guizhou, there were 4 kinds of genotypes (1, 2, 3 and 6) and 7 kinds of subgenotypes (1a, 1b, 2a, 2b, 3a, 3b and 6a). The subgenotypes 1a, 1b, 2a, 2b, 3a, 3b and 6a accounted for 5.1% (11/216), 36.1% (78/216), 3.7% (8/216), 0.9% (2/216), 7.4% (16/216), 27.8% (60/216) and 17.1% (37/216). In addition, there were 4 cases of rare subtypes (4a/6n), accounting for 1.9% (4/216). The top 3 gene subtypes were 3b, 1b and 6a in Sichuan; 3b, 1b and 2a/3a in Yunnan; and and 1b, 6a and 3b in Guizhou respectively. 3b (33.1%) and 1b (48.3%) were the main subtypes in the male and female patients respectively; 1b (39.8%), 3b (18.6%) and 6a (15.9%) were the main subtypes in the patients over 40 years while 3b (37.9%), 1b (32.1%) and 6a (18.4%) were the main subtypes in the patients younger than 40 years. The main mode of infection was blood transfusion (40.1%), and other unknown reasons also accounted for a large proportion (33.8%). 1b was the main subtype in acute hepatitis C, chronic hepatitis C, liver cirrhosis after hepatitis C and liver cancer after hepatitis C, followed by 3b and 6a. In the patients with hepatitis C, the liver function impairment indicators and HCV load of the 1b subtype were significantly higher than those of other gene subtypes (P < 0.05). Conclusions HCV subtype 1b is the most predominant subtype in hepatitis C patients of Han nationality in Sichuan, Yunnan and Guizhou of southwest China. 3b and 6a subtypes also occupy a very high proportion; and the distribution of gene subtypes is diversified. 1b subgenotype of high HCV load is more likely to cause serious damage of liver function and chronic hepatitis, liver fibrosis and hepatic carcinoma.