丙型肝炎病毒基因酶切分型及其在干扰素治疗中的应用

为了解广州地区丙型肝炎病毒（ＨＣＶ）感染的基因型及其与对干扰素应答效果的关系，应用逆转录－聚会酶链反应（ＲＴ－ＰＣＲ）对１３３例丙型肝炎病人血清进行ＨＣＶ５’端非编码区基因片段扩增，对１１６例阳性ＰＣＲ产物进行酶切分型。并观察了国产基因工程干扰素对其中５１例慢性丙型肝炎的疗效，结果，ＨＣＶⅡ型感染１０１例（８７．１％），Ｄ型感染１５例（１２．９％），在干扰素治疗的病例中，Ⅱ型感染（４１例）的应答率为４３．９％（１８例），其中完全应答与部分应答分别为２６．８％（１１例）和１７．１％（７例）；Ⅲ型感染（１０例）的应答率为８０％（８例），其中完全应答与部分应答分别为６０％（６例）和２０％（２例）。两组比较有显著性差异（Ｐ＜０．０５）。表明ＨＣＶⅡ型感染是广州地区的优势株，Ⅲ型感染对干扰素应答较Ⅱ型敏感。     

Automated RIBA Hepatitis C Virus (HCV) Strip Immunoblot Assay for Reproducible HCV Diagnosis

A comparison between the CHIRON RIBA hepatitis C virus (HCV) processor and manual systems was performed by using 88 specimens repeatedly reactive by the second-generation HCV enzyme-linked immunosorbent assay (ELISA) (HCV 2.0 ELISA) and 111 random specimens from volunteer donors. For the second-generation RIBA HCV strip immunoblot assay (SIA) (RIBA HCV 2.0 SIA), test results correlated strongly between the manual and the automated runs (kappa value, 0.937). For the RIBA HCV 3.0 SIA, the correlation of the test results was also high (kappa value, 0.899). Among the specimens with positive results by RIBA HCV 2.0 and 3.0 SIAs, there was a very strong concordance of the test results between the manual and the automated runs with regard to the reactive bands. Nine samples had discordant results between the manual and the automated runs; this was probably attributable to increased variability in antigen scores close to the cutoff values for both tests. Run-to-run and within-run testing by the CHIRON RIBA HCV Processor System showed a very low rate of conflicting values. In conclusion, the CHIRON RIBA HCV Processor System is capable of performing RIBA HCV 2.0 and 3.0 SIAs accurately with minimal operator involvement. In addition, the CHIRON RIBA HCV Processor System shows excellent reproducibility, with the potential for operator-to-operator and site-to-site variability being greatly reduced. Our data indicate that this novel methodology may be very useful for supplemental anti-HCV testing of specimens repeatedly reactive by ELISA in routine clinical assessments and epidemiologic evaluations.     

Serotyping and genotyping of hepatitis C virus (HCV) strains in chronic HCV infection

Hepatitis C virus (HCV) genotypes can be established by methods based on PCR typing and serological typing. The accuracy of these methods depends on their sensitivity and specificity. These should be compared with the reference method, direct sequencing, and analysis of viral genomes. Among the serologic methods recently developed, the performance of a new serotyping assay (RIBA HCV 3.0 SIA, Chiron corporation, Emeryville) was assessed using a panel of 147 well-characterized French isolates from chronic hepatitis C patients. Definitive genotypes of the isolates were established by direct sequencing in 5′ NC and in some cases in NS-5B. HCV serotypes 1, 2, and 3 were determined by measuring type specific antibodies to core and NS-4 derived peptide antigens. Of the 147 sera, serotypic-specific antibodies were detected in 136 (sensitivity, 92.5%). The specificity of the RIBA SIA HCV serotyping assay was 92.6% (including samples with mixed results); without these, the specificity was 80.1%. Analysis of the 28 discrepant samples showed that (1) a different serotype was found in 18 samples including five for genotype 1, three for genotype 2, two for genotype 3, five for genotype 4, and three for genotype 5, and that (2) ten patients showed a reactivity with mixed serotypes, one had circulating antibodies to type 1 or 2, and nine had circulating antibodies to type 1 or 3. In summary, except for genotypes 4 and 5, the results of the test were well correlated (85.7%) with those of direct sequence genotyping. The former test is rapid and does not require the strict HCV RNA storage and preservation conditions of the latter. This new method may thus be considered as an alternative for HCV typing. However, although it is convenient, its lower sensitivity compared to the molecular typing method and the discrepant results limit its routine use in a clinical context. J. Med. Virol. 52:391–395, 1997. © 1997 Wiley-Liss, Inc.     

Hepatitis C virus (HCV) infection in childhood

We studied the prevalence of hepatitis C virus (HCV) infection in childhood by determining HCV antibody (Ortho Diagnostic Systems, USA). Among patients with post-transfusion non-A, non-B hepatitis, anti-HCV was positive in 8 (72.7%) out of 11 patients. On the other hand, only 1 (25.0%) out of 4 patients of the children with acute non-A, non-B hepatitis, and only 1 (20.0%) out of 5 with chronic non-A, non-B hepatitis patients were positive for anti-HCV. Among the infants with non-A, non-B hepatitis, anti-HCV was positive in 3 (7.5%) out of 40 infants. To demonstrate mother-to-infant transmission of HCV, we examined 7 infants born to 4 anti-HCV positive mothers for their GPT values and anti-HCV. Liver dysfunction occurred in all the infants but one. And 1 infant was positive for anti-HCV. This infant with positive anti-HCV and liver dysfunction was considered to be a case of mother-to-infant transmission of HCV. And in the infants with liver dysfunction and negative anti-HCV, it was suggested that liver dysfunction occurred in association with HCV infection.     

Epidemiology of hepatitis C virus (HCV) infection

Hepatitis C virus remains a large health care burden to the world. Incidence rates across the world fluctuate and are difficult to calculate given the asymptomatic, often latent nature of the disease prior to clinical presentation. Prevalence rates across the world have changed as well with more countries aware of transfusion-related hepatitis C and more and more evidence supporting intravenous drug use as the leading risk factor of spread of the virus. This article reviews current hepatitis C virus prevalence and genotype data and examines the different risk factors associated with the virus.     

Influence of hepatitis C virus (HCV) genotypes on HCV recombinant immunoblot assay patterns.

Ninety-six patients with chronic hepatitis C were studied. A second-generation recombinant immunoblot assay detected anti-NS4 antibodies significantly more often in patients infected by hepatitis C virus genotype 1 than in patients infected by other types. By a third-generation recombinant immunoblot assay, the prevalences of the four antibodies measured did not differ according to the hepatitis C virus genotype.     

HCV LNAzyme对病毒5'非编码区基因调控的特异性抑制作用

目的 探讨针对丙肝病毒5 '非编码区内源性核糖体进入位点的锁核酸核酶(LNAzyme)对病毒基因复制与表达的特异性抑制作用.方法 设计合成能切割HCV-5'-NCR-IRES位点的DNAzyme、硫代DNAzyme和LNAzyme.实验设对照组和实验组.对照组包括空白对照组、脂质体对照组和无关LNAzyme对照组.实验组包括DNAzyme、硫代DNAzyme组和LNAzyme组.以阳离子脂质体介导转染hepG2.9706细胞,用荧光定量PCR和化学发光技术分别监测24、48和96 h细胞培养上清液中HCV RNA含量及荧光素酶基因表达;四甲基偶氮唑蓝(MTT)法监测细胞活性.结果 加入核酶后,LNAzyme对HCV RNA复制和荧光素酶基因表达的抑制作用最强(P＜0.05),平均抑制率分别为48.02％和53.05％,且随用药时间延长,抑制率呈增高趋势,96 h后,平均抑制率分别为81.21％和84.25％.LNAzyme对细胞活性无影响.结论 LNAzyme能特异性抑制丙型肝炎病毒5 '非编码区的基因调控,且优于硫代修饰的DNAzyme.     

Evaluation of the clinical usefulness of COBAS AMPLICOR HCV MONITOR assay (ver2.0): Comparison with AMPLICOR HCV MONITOR assay (ver1.0) and HCV core protein level

The quantitation of serum levels of hepatitis C virus (HCV) RNA in chronic hepatitis C has been regarded as one of the most important indicators for the outcome of interferon (IFN) therapy. The AMPLICOR HCV MONITOR version 1.0 (AMPLICOR v1.0) assay is widely used for the evaluation of the HCV level. A new generation assay called the COBAS AMPLICOR HCV MONITOR version 2.0 (COBAS v2.0) assay, which is semiautomated and modified to amplify all genotypes equally, has been developed. The aim of this study was to evaluate the clinical relevance of the COBAS v2.0 assay in comparison with the AMPLICOR v1.0 assay and HCV core protein assay in patients with chronic hepatitis C before IFN therapy. HCV RNA was detectable in 230 cases (97.5%) and undetectable in 6 cases (2.5%) by the COBAS v2.0 assay. The RNA levels measured by the AMPLICOR v1.0 assay correlated significantly with those measured by the COBAS v2.0 assay, and the sensitivity of the new version 2.0 assay was better than that of version 1.0, especially in serotype 2. In relation to the outcome of IFN therapy, HCV RNA levels from virologically sustained responders by the AMPLICOR v1.0 assay were 82.3 +/- 22.9 kcopies/ml in serotype 1 and 36.9 +/- 13.4 kcopies/ml in serotype 2, and those from virologically nonsustained responders were 525.2 +/- 48.6 kcopies/ml in serotype 1 and 76.7 +/- 19.5 kcopies/ml in serotype 2.The rates of sustained response to <100 kcopies/ml were 34/63 (54.0%) in serotype 1 and 24/48 (50.0%) in serotype 2. A statistically significant virological response was seen in serotype 1 (P < 0.0001), but not in serotype 2. In contrast, the levels in virologically sustained responders by the COBAS v2.0 assay were 88.2 +/- 20.5 KIU/ml in serotype 1 and 136.8 +/- 40.1 KIU/ml in serotype 2, and those in virologically nonsustained responders were 608.8 +/- 48.4 KIU/ml in serotype 1 and 328.3 +/- 62.8 KIU/ml in serotype 2. The rates of sustained response to <100 KIU/ml were 33/60 (55.0%) in serotype 1 and 21/35 (60.0%) in serotype 2. Statistical significance in virological response was seen in both serotype 1 (P < 0.0001) and serotype 2 (P < 0.05). Although the sensitivity of the HCV core protein assay was lower than that with the COBAS v2.0 assay, the HCV core protein levels also correlated well with the results of the COBAS v2.0 assay. The HCV core protein levels of virologically sustained responders were 37.6 +/- 12.0 pg/ml in serotype 1, 81.3 +/- 37.0 pg/ml in serotype 2, and those of virologically nonsustained responders were 289.9 +/- 23.5 pg/ml in serotype 1, 191.4 +/- 32.1 pg/ml in serotype 2. This assay could predict the outcome of IFN therapy in both serotype 1 (P < 0.0001) and serotype 2 (P < 0.05). Thus, both the COBAS v2.0 assay and the HCV core protein assay showed that the viral load was an indicator of virologically sustained response in serotype 2 and in serotype 1.     

Use of an Anti-Hepatitis C Virus (HCV) IgG Avidity Assay To Identify Recent HCV Infection

There is no reliable and simple diagnostic marker available to diagnose recent hepatitis C virus (HCV) infection. It has been shown that the avidity of specific IgG antibody is low in primary viral infection and increases with time. We report the development of an anti-HCV avidity assay derived from a commercially available test. A panel of 117 sera was first examined for IgG avidity. It was composed of samples from patients with recent (group 1, n = 14), chronic (group 2, n = 70), and resolved (group 3, n = 33) HCV infections. Avidity index (AI) values observed in recently infected patients were significantly lower (12.0% ± 9.2% [mean ± standard deviation]) than those found in chronic carriers (83.1% ± 15.2%). Using a threshold of 43.0%, this assay distinguished between groups 1 and 2 with very high sensitivity (98%) and specificity (100%). For group 3, a broader distribution of the AI values was observed (54.8% ± 27.3%), suggesting that this index would not be useful in HCV RNA-negative patients. Blind validation of the test was carried out with a panel of 36 serum samples from 17 HCV seroconverters. The assay described here is a useful tool to distinguish recent from chronic infection in HCV-viremic patients.Hepatitis C virus (HCV) can be acquired or transmitted via any blood-borne route. Intravenous drug use has become the main transmission mechanism of HCV in Western countries (5). Patients with acute HCV infection are generally asymptomatic. Those who are symptomatic may exhibit jaundice but more often complain of fatigue, nausea, abdominal pain, or flulike symptoms. An average of 30% of patients with acute hepatitis C experience spontaneous viral clearance during the first 3 months after the clinical onset of the disease (15). Chronic disease should be considered if viremia persists for more than 6 months. Chronic hepatitis C is also generally clinically silent for a sustained period of time. This results in fortuitous diagnosis at a late stage of disease in most cases.There is no reliable and simple diagnostic marker currently available to diagnose recent hepatitis C virus infection. Increases in serum aminotransferase may be indicative of a recent infection but are also seen in exacerbation phases of chronic hepatitis C. They may also arise due to other acute disorders, such as alcohol-induced hepatitis. Specific IgM responses to HCV do not serve as useful markers in the diagnosis of recent hepatitis C, because IgM may be present at similar levels in both recent and chronic disease (14, 20). HCV seroconversion remains the only useful marker of recent HCV infection.An accurate estimate of HCV incidence would be useful to target interventions to high-risk populations but is a major challenge for epidemiologists. The avidity of an antibody may be an early and reliable marker of recent viral infection. Avidity increases progressively with time after exposure to an immunogen due to rapid mutations in the DNA coding for the variable part of the antibody (8, 19). Antibodies of low avidity are usually indicative of recent infection. Avidity assays have been developed for many viral infections (rubella virus, cytomegalovirus, varicella-zoster virus, and HIV-1) (2, 6, 7, 10, 16). Commercial immunoassays for anti-HCV antibody detection have been adapted to test for avidity. They have confirmed that anti-HCV avidity increases with time after primary infection (3, 11, 17). However, the limited evaluation of such assays in small populations has hampered their development for use in clinical practice. More recently, the development of an “in-house” anti-HCV IgG avidity assay, using a combination of target antigens, has been validated with seroconversion panels and samples from chronically infected individuals (12).Here, we report the development of an anti-HCV avidity assay, derived from a commercially available third-generation enzyme-linked immunosorbent assay (ELISA). The test was evaluated using a panel of established recent and chronic HCV infections. The usefulness and the clinical significance of the anti-HCV avidity index (AI) are also discussed.     

Clinical significance of serum hepatitis C virus (HCV) RNA as marker of HCV infection.

We have evaluated the clinical significance of hepatitis C virus (HCV) RNA determination by analyzing a group of 221 hospitalized patients with abnormal liver function tests. Serum HCV RNA was detected by "nested" PCR amplification followed by nonisotopic hybridization. Of the 200 (90.5%) patients with anti-HCV-positive enzyme-linked immunosorbent assay results, 152 (76%) were RIBA reactive, 47 (23.5%) had indeterminate results, and 1 (0.5%) was nonreactive. Of the 180 (90%) patients positive for anti-HCV and HCV RNA, 138 (76.7%) were RIBA reactive and 42 (23.3%) were RIBA indeterminate. The pattern of RIBA reactivity did not correlate with the presence of HCV RNA. Elevated alanine aminotransferase levels were associated neither with the presence of viremia nor with the RIBA pattern. Histological findings consistent with non-A non-B hepatitis correlated with the presence of HCV RNA but not with the RIBA pattern. HCV RNA was detected in 11 of 21 (52.4%) anti-HCV-negative patients. These 11 patients were either immunosuppressed or in the prodromic phase of acute hepatitis C. Circulating HCV RNA can therefore be described as being predictive of virus-induced liver damage in anti-HCV-positive patients and may be useful in the diagnosis of HCV infection in anti-HCV-negative immunosuppressed patients or in those with early acute infection.     

Hepatitis C virus (HCV) infection and hepatic steatosis

There are two discrete forms of steatosis that may be found in patients infected with hepatitis C virus (HCV). Metabolic steatosis can coexist with HCV, regardless of genotype, in patients with risk factors such as obesity, hyperlipidemia, and insulin resistance. The second form of hepatic steatosis in HCV patients is a result of the direct cytopathic effect of genotype 3 viral infections. There have been proposed mechanisms for this process but it remains elusive. Both categories of steatosis tend to hasten the progression of liver fibrosis and therefore prompt recognition and management should be initiated in patients with HCV and steatosis. The authors review the current understanding of the relationship between hepatitis C infection and hepatic steatosis and discuss future research directions.     

Morphine enhances hepatitis C virus (HCV) replicon expression

Little information is available regarding whether substance abuse enhances hepatitis C virus (HCV) replication and promotes HCV disease progression. We investigated whether morphine alters HCV mRNA expression in HCV replicon-containing liver cells. Morphine significantly increased HCV mRNA expression, an effect which could be abolished by either of the opioid receptor antagonists, naltrexone or beta-funaltrexamine. Investigation of the mechanism responsible for this enhancement of HCV replicon expression demonstrated that morphine activated NF-kappaB promoter and that caffeic acid phenethyl ester, a specific inhibitor of the activation of NF-kappaB, blocked morphine-activated HCV RNA expression. In addition, morphine compromised the anti-HCV effect of interferon alpha (IFN-alpha). Our in vitro data indicate that morphine may play an important role as a positive regulator of HCV replication in human hepatic cells and may compromise IFN-alpha therapy.     

Hepatitis B virus (HBV) and hepatitis C virus (HCV) dual infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections account for a substantial proportion of liver diseases worldwide. Because the two hepatotropic viruses share same modes of transmission, coinfection with the two viruses is not uncommon, especially in areas with a high prevalence of HBV infection and among people at high risk for parenteral infection. Patients with dual HBV and HCV infection have more severe liver disease, and are at an increased risk for progression to hepatocellular carcinoma (HCC). Treatment of viral hepatitis due to dual HBV/HCV infection represents a challenge.     

Intermittent detection of hepatitis C virus (HCV) in semen from men with human immunodeficiency virus type 1 (HIV-1) and HCV

HCV is usually transmitted via the blood, but HCV RNA has been detected recently in seminal fluid. This study was done to study HCV seminal shedding and factors that could influence the presence of HCV in the seminal fluid of men coinfected with HCV and HIV-1. HCV and HIV-1 genomes were assayed in multiple paired blood and semen samples obtained from 35 men enrolled in an assisted medical procreation protocol. HCV RNA was found intermittently in semen samples from 9 patients (25.7%). Samples from 9 men with HCV RNA in their semen and 26 men without were compared to further analyze these parameters. No correlation was found between HCV RNA in the seminal fluid and age, HCV virus load, the duration of HIV-1 infection, HIV treatment, the CD4(+) cell count, HIV-1 virus load or HIV-1 detection in the semen. The intermittent detection of HCV RNA in semen samples support the systematic search for HCV RNA in semen and the use of processed spermatozoa in assisted medical procreation of infertile HCV serodiscordant couples.     

Lack of monomeric IgM anti-hepatitis C virus (HCV) core antibodies in patients with chronic HCV infection

Antibodies of the IgM class against the hepatitis C virus core antigen are found in up to 70% of patients with either acute or chronic hepatitis C. The sedimentation rate of such IgM was analyzed by rate-zonal centrifugation of nine sera taken from seven patients, two acutely and five persistently infected with hepatitis C virus. All patients had circulating high-molecular weight (i.e. pentameric) IgM, indicating that the production of low molecular weight IgM, commonly observed in other persistent viral infections, does not apply to hepatitis C virus and cannot be used to distinguish acute from chronic hepatitis C virus infection.