Analysis of the mechanism of liver injury and carcinogenesis in HCV infection

自从丙型肝炎病毒（HCV）基因组从实验感染的黑猩猩血浆中克隆出来后，丙型肝炎病毒抗体的检测表明，HCV是大多数非甲非乙型（NANB）肝炎的病原体。我们评估了HCV核心蛋白抗体的流行情况，发现HCV与95%以上的NANB慢性肝病有关，抗HCV核心蛋白的存在与HCV携带者密切相关。我们通过竞争性RT-PCR检测定量血清中的HCV RNA，以将HCV的复制水平与（1）携带状态的各个阶段或（2）对干扰素（IFN）治疗的持续应答相关联。血清中HCV RNA的量范围为10^4至10^<9.5>拷贝/mL血清。无症状献血员和慢性迁延性肝炎患者的HCVRNA滴度低于慢性活动性肝炎、肝硬化和肝细胞癌（HCC）患者。初始滴度 ...更多信息 长期应答者治疗前HCVRNA水平明显低于短期应答者和无应答者。多因素分析显示，治疗前HCVRNA滴度是IFN治疗持续应答的最强独立预测因子。我们通过免疫组织化学和原位杂交技术确定了HCV感染肝细胞的定位。在不到50%的研究标本中发现阳性染色或信号。阳性肝细胞散在分布于肝小叶内。小叶内炎症和纤维化在阳性样本中的评分高于阴性样本。用PCR方法检测肝细胞癌患者肝组织中特异性HCVRNA，结果表明，无论癌组织还是非癌组织中，HCVRNA既可扩增出正链，也可扩增出负链。结果表明，晚期肝病患者体内HCV复制水平较高，病毒复制水平升高可能在肝损伤、肝病进展及肝癌发生中起重要作用。少

Since the genome of hepatitis C virus (HCV) was been cloned from experimentally infected chimpanzee plasma, testing for antibody to hepatitis C virus has shown that HCV is the etiological agent for most cases of non-A, non-B (NANB) hepatitis. We evaluated the prevalence of antibody to the core protein of HCV and found that HCV is related with more than 95% of NANB chronic liver disease and that there is a close correlation between the presence of anti-HCV core and HCV carriers. We quantified HCV RNA in serum by the competitive RT-PCR assay to correlate the replicative level of HCV with (1)various stages of the carrier states or (2)a sustained response to interferon (IFN) therapy. The amounts of HCV RNA in serum ranged from 10^4 to 10^<9.5> copies/mL serum. The titer of HCV RNA were lower in asymptomatic blood donors and in patients with chronic persistent hepatitis compared with those having chronic active hepatitis, liver cirrhosis and hepatocellular carcinoma (HCC). The initial titer … More of HCV RNA before IFN therapy of long-term responders were significantly lower than those of short-term responders and non-responders. Multivariate analysis showed that the HCV RNA titer before therapy was the strongest independent predictor of a sustained response to IFN therapy. We determined the localization of the HCV-infected hepatocytes by immunohistochemical studies and "in situ"hybridization technique. Positive staining or signal was found in less than 50% of studied specimens. Hepatocytes with positive results were scattered in the lobules. Intralobular inflammation and fibrosis had higher scores for samples with positive rather than negative results. In liver tissue of patients with HCC, detection of strand-specific HCV RNA by PCR showed that not only positive-strand but also negative-strand could be amplified in both cancerous and non- cancerous liver tissue. These results showed that the replicative level of HCV is higher in advanced liver disease, and that elevation of viral replication might play an important role in liver injury, progression of liver disease and carcinogenesis. Less