Effect of interferon on GB virus C and hepatitis C virus in hepatitis patients with the co-infection

Of 74 patients who were infected with hepatitis C virus (HCV) and received interferon, 12 (16%) were positive for RNA of GB virus C (GBV-C). RNA of GBV-C was determined in sera from the co-infected patients retrospectively, and the effect of interferon on GBV-C was compared with that on HCV in them. Titers of both GBV-C and HCV RNAs decreased during interferon in all of them. Two patients lost both GBV-C and HCV RNAs and remained clear until 6 months after treatment with interferon, while 2 lost RNA for GBV-C only and 2 for HCV RNA alone. Low pre-treatment RNA titers of GBV-C and HCV correlated with the efficacy of interferon in clearing. Alanine aminotransferase returned to normal only in the patients who lost HCV RNA, regardless of the persistence or loss GBV-C RNA. These results indicate that the response to interferon of GBV-C is comparable to but independent of that of HCV and that the persistence of GBV-C would not prevent the normalization of aminotransferases in response to interferon in patients with chronic hepatitis C. J. Med. Virol. 52:156–160, 1997. © 1997 Wiley-Liss, Inc.     

IgG1 anti-P2 as a marker of response to interferon in patients with chronic hepatitis C.

To study the relations of antibody production to long-term outcomes after interferon (IFN) treatment in patients with chronic hepatitis C (CH-C), we used ELISA to measure the levels of antibodies against HCV core protein and peptides. Samples from 21 complete responders and 36 non-responders were collected before IFN therapy, soon after the end of IFN therapy and 6 months later. Using a set of 19 synthesized HCV core peptide antigens, we found that anti-P2 (11-25a.a.) was the most prevalent of all IgG antibodies (93%: 39/42). Among complete responders, IgG1 anti-P2 levels had fallen by the end of IFN therapy (from 79.8 +/- 60.4-46.1 +/- 44.2: P < 0.01), and were lower still 6 months after the end of IFN therapy (31.0 +/- 35.2: P < 0.001); this change was the greatest of all antibodies studied. Among the non-responders, there was no change within the follow-up period. Soon after the end of IFN therapy, IgG1 anti-P2 levels were more than 30% lower than the initial value in more than two-thirds of the complete responders, but in only one-third of the non-responders (14/20 vs. 8/25: P < 0.05). Six months after the end of IFN therapy, IgG1 anti-P2 levels were more than 30% lower than the initial value in more than 85% of the complete responders, but in only 12% of the non-responders (17/20 vs. 3/25: P < 0.001). In conclusion, the changes in levels of IgG1 anti-P2 paralleled the activity of chronic hepatitis C after IFN therapy, and IgG1 anti-P2 levels may be markers of the efficacy of IFN therapy.     

Antibody responses against B-cell epitopes of the hypervariable region 1 of hepatitis C virus in self-limiting and chronic human hepatitis C followed-up using consensus peptides.

A rare collection of serum samples from patients with hepatitis C virus (HCV) infection followed up from the onset of clinical symptoms was acquired. RNA corresponding to the hypervariable region 1 (HVR1) of E2 protein of HCV isolated from nine patients was reverse-transcribed, amplified, sequenced, and HVR1 amino acid sequences were deduced. These sequences and a selection of HVR1 amino acid sequences of matching HCV genotypes from protein and translated DNA sequence databanks were used to create the HVR1 amino acid consensus. The degenerated peptides mimicking N- and C-termini of the consensus were synthesized. Most (76%) of 17 patients followed up for the period from 1 week to a minimum of 7 months from the onset of acute symptoms developed antibodies reacting with peptides representing N- and/or C- termini of HVR1. Antibody recognition of the consensus HVR1 peptides indicates that the variability of HVR1 sequence on the protein level is limited with certain conserved structure(s) being untouched. A tendency was observed for a slower development of anti-HVR1 antibody response in patients developing chronic HCV, as compared to those with self-limiting HCV infection.     

Interferon therapy in chronic hepatitis C virus: Evidence of different outcome with respect to different viral strains

The aim of the study was to assess the role of different viral strains of hepatitis C virus (HCV) in determining the outcome of the alpha-interferon (IFN) therapy. Fifty-seven patients (34 from Italy and 23 from Japan) with HCV-positive liver disease were enrolled in the study. The NS4 region of HCV was amplified in sera by “nested” polymerase chain reaction (PCR) using a primer pair synthesized according to the sequence of JK-1. The NS4 region was positive in 14 (41%) Italian and in 13 (56%) Japanese patients. In positive patients the sequence of the NS4 region was also obtained. Subsequently, HCV genotype was determined in all patients by PCR amplification of the core region. All patients received recombinant alpha2a-interferon (IFN), 6 million units 3 times a week for 1 month followed by 3 million units 3 times a week for 5 months. The patients were followed for 1 year after the end of treatment. At the end of the follow-up, 17 (30%) had sustained normal levels of serum alanine aminotransferase (ALT). The outcome of treatment was not correlated with race, age, sex, histology, and pretreatment ALT level, but was significantly (P < 0.00001) associated with the presence of both the NS4-JK-1 region and HCV type II. Among the 27 NS4-positive patients, only 1 patient (3.7%) achieved a complete response, whereas the remaining 26 patients (96.3%) either were non-responders or relapsed after IFN was discontinued. In contrast, among the 30 NS4-JK-1-negative patients, 15 (53%) had a sustained remission. HCV genotyping showed type I in 3 (6%), type II in 40 (74%), type III in 4 (7%), and type IV in 3 (6%) cases. Coinfection was present in 4 (7%), while in 3 cases amplification was not obtained. Patients with type II were all non-responders or relapsers, while a response to the treatment was oberved in 17 of 17 (100%) of the remaining patients. These data indicate that the presence of JK-1 variant of HCV or HCV type II is almost always predictive of a poor response rate Of IFN therapy. © 1995 Wiley-Liss, Inc.     

Genetic complexity of the hypervariable region 1 (HVR1) of hepatitis C virus (HCV): Influence on the characteristics of the infection and responses to interferon alfa therapy in patients with chronic hepatitis C

HCV exists within its host as pools of related genetic variants referred to as quasispecies. The hypervariable region 1 (HVR1) of the E2 envelope gene is subjected to strong selective pressure from neutralizing antibodies. The genetic complexity of this region is defined as the total number of genetic variants within the quasispecies population. The genetic complexity of the HVR1 region was examined in patients with chronic hepatitis C and its relationship with the epidemiology of HCV infection, and its influence on liver disease and the response to interferon treatment were determined in 114 patients with chronic hepatitis C. The genetic complexity of the HVR1 major variants was measured before treatment by using a polymerase chain reaction (PCR)-single-strand conformation polymorphism (SSCP) technique, and was compared with epidemiological, clinical, virological and histological features. The patients were treated with 3 megaunits of interferon (IFN) alfa for 3 to 6 months and the response to treatment was assessed at 3, 6 and 12 months. The HVR1 could be studied in 101 of the 114 patients (89%). Genetic complexity was significantly higher in patients infected through blood transfusion than intravenous drug use (mean complexity index: 5.7 ± 2.3 vs. 4.7 ± 1.5, respectively; P = 0.04). This relationship was independent of age and the estimated time since infection. No significant relationship was found with other parameters of infection or liver disease. In univariate analysis, the genetic complexity of HVR1 major variants did not affect the rates of ALT normalization at months 3 and 6 of IFN treatment. HVR1 genetic complexity was lower in patients with a sustained virological response than in non-responders (4.0 ± 1.7 vs. 5.4 ± 2.0, respectively; P = 0.07). In multivariate analysis of pretreatment parameters associated with a sustained virological response to treatment, three parameters appeared to be independent predictors of such a response: a low viral load (P < 0.04), a low anti-HCV core IgM titer (P = 0.03) and a low genetic complexity of HVR1 major variants (P < 0.04). In conclusion, the HVR1 of HCV has a quasispecies distribution in infected individuals. Its genetic complexity is significantly higher in transfusion recipients than in intravenous drug users, suggesting that the size of the initial inoculum affects the later emergence and development of viral quasispecies. The genetic complexity of HVR1, together with viral load and the anti-HCV IgM titer, are independent predictors of a sustained virological response to IFN alfa in patients with chronic hepatitis C. J. Med. Virol. 54:256–264, 1998. © 1998 Wiley-Liss, Inc.     

Comparison of the hypervariable region of hepatitis C virus genomes in plasma and liver

Nucleotide sequences of the hypervariable region of hepatitis C virus genomes obtained from plasma change rapidly during the course of in fection and are believed to play a part in immunological escape and consequently in the development of persistent infection. It is not known, however, whether these changes also occur in the liver. To clarify this aspect, RNA was extracted from the plasma and liver tissue of eight patients with chronic hepatitis C. After cDNA synthesis, DNA fragments that included the hypervariable region were amplified by the polymerase chain reaction. Consensus nucleotide sequences were determined directly from the polymerase chain reaction products by the dideoxy chain termination method. The diversity of the hypervariable region was analyzed further by the polymerase chain reaction-single strand conformation polymorphism analysis. Consensus nucleotide sequences of the hypervariable region were identical between the plasma and the liver in each patient. The polymerase chain reaction-single strand conformation polymorphism analysis showed multiple DNA bands that represented different hypervariable region sequences. Comparison of the single strand conformation polymorphism patterns revealed that the number, the mobility, and the density of bands were the same between the plasma and the liver. It is concluded that the population and the diversity of hepatitis C virus quasispecies as detected by the hypervariable region sequence are the same between the plasma and the liver despite rapid mutations, indicating that rapid changes in the population of hepatitis C virus quasispecies also occur in the liver. © 1995 Wiley-Liss, Inc.     

HCV 1b亚型ISDR变异影响PEG-IFN/RBV抗病毒疗效的新特点分析

目的探讨HCV干扰素敏感决定区（ISDR）氨基酸（aa）序列变异度对聚乙二醇干扰素（PEG-IFN）联合利巴韦林（RBV）治疗1b亚型慢性丙型肝炎（CHC）疗效的影响。方法 58例HCV1b亚型慢性感染者采用PEG-IFN/RBV联合方案治疗48周,并随访24周。定量检测血清HCV RNA,逆转录-聚合酶链反应扩增治疗前血标本中HCV ISDR片段并测序,MEGA4分析氨基酸序列变异度;二分类Logistic回归分析各变量与持续病毒学应答（SVR）之间的关系。结果治疗前血清HCV的ISDR氨基酸序列与HCVJ株比较,15例为野生型（未突变）,42例为中间型（1-3个突变）,1例为突变型（≥4个突变）。其中2218位点突变最多,约为60.3%（35/58）。ISDRaa突变数目与SVR关系密切（P=0.000）,ISDRaa突变数≥2的CHC组所获得的EVR和SVR明显高于aa突变数〈2的CHC组（P=0.041/P=0.012）。结论华南HCV1b亚型ISDR突变型（氨基酸变异≥4）极少。ISDRaa变异能够预测SVR;采用PEG-IFN/RBV联合方案治疗,对SVR有预测价值的ISDRaa突变数可由4个减少为2个。     

Drift in the hypervariable region of the hepatitis C virus during 27 years in two patients

Serial serum samples were obtained over a 27-year period from a hepatitis C virus (HCV)-infected patient and from a nurse who appeared to become infected by this patient. The hypervariable region 1 (HVR1) and 5'noncoding region (5'NCR) of the HCV genome were amplified from each serum sample by polymerase chain reaction (PCR) and cloned. In the first serum specimen from the patient and the first two serum specimens from the nurse, most of the 20 clones from each serum sample had one common sequence in the HVR1 gene. All later serum samples contained a heterogeneous mixture of HCV quasispecies. The uniformity of the HVR1 sequence in the early samples and the emergence of greater diversity in later serum samples is consistent with the apparent transmission of HCV between the patient and nurse and the eventual emergence of other quasispecies as the virus replicated in the new host. In addition, the immune globulin given to the nurse may have been responsible for some of the HCV quasispecies changes observed in her serum.     

Efficacy of interferon-based antiviral therapy in patients with chronic hepatitis C infected with genotype 5: a meta-analysis of two large prospective clinical trials

The characteristics and response rate to pegylated interferon and ribavirin (PEG-INF + RBV) of patients with chronic hepatitis C infected with genotype 5 are poorly documented. A meta-analysis of two large phase III/IV prospective randomized clinical trials conducted in Belgium in patients with chronic hepatitis C (n = 1,073 patients) was performed in order to compare the response to antiviral therapy of hepatitis C virus (HCV) genotype 5 with that of other HCV genotypes. A subset of HCV-1 infected patients selected from within the study database were selected to match the HCV-5 sample for known prognostic factors. In Belgium HCV-5 is responsible for a significant minority of cases of chronic hepatitis C CHC (4.5%) and is characterized by a more advanced age (58.4 years), a high frequency of cirrhosis (27.7%), a specific mode of HCV acquisition, and a particular geographic origin (66.7% of patients from West Flanders). The primary comparative analysis showed that response to treatment with PEG-INF + RBV of HCV-5 is similar to HCV-1 and lower compared to HCV-2/3. The analysis of the matched patient subgroup demonstrates that the HCV-5 "intrinsic sensitivity" to PEG-IFN + RBV therapy is identical to HCV-1, with a sustained virological response of 55% in both groups. In contrast to previous publications, this meta-analysis suggests that HCV-5 response to treatment is closer to HCV-1 than to HCV-2/3 and suggests that in Belgium HCV-5 infection should be treated with the same antiviral regimen as HCV-1.     

Virus clearance reduces bone fracture in postmenopausal women with osteoporosis and chronic liver disease caused by hepatitis C virus

Osteoporosis is often present in postmenopausal women. The aim of this retrospective cohort study was to assess the cumulative incidence and predictive factors for bone fracture after cessation of interferon (IFN) in postmenopausal women with osteoporosis and chronic liver disease caused by hepatitis C virus (HCV). A total of 420 postmenopausal women treated with IFN monotherapy were enrolled. The mean observation period was 7.2 years. The primary goal was the development of bone fracture. Evaluation was carried out by using the Kaplan–Meier method and the Cox proportional hazards analysis. Thirty‐one out of 420 patients sustained bone fracture. The cumulative development rate of bone fracture was 3.6% at 5th year, 9.2% at 10th year, and 17.4% at 15th year. Multivariate Cox proportional hazards analysis showed that bone fracture after cessation of IFN therapy occurred when histological staging of the liver was advanced (hazard ratio (HR): 2.54; 95% confidence interval (CI) = 1.21–5.31; P = 0.013), serum albumin level was < 3.5g/dl (HR: 2.25; 95% CI = 1.10–4.59; P = 0.026), and virus clearance was not achieved (HR: 3.65; 95% CI = 1.11–12.05; P = 0.033). The results indicate that virus clearance causes a reduction of two‐thirds in the risk of bone fracture after cessation of IFN therapy in postmenopausal women with osteoporosis and chronic liver disease caused by HCV. J. Med. Virol. 82:390–395, 2010. © 2010 Wiley‐Liss, Inc.     

Genetic characterization of hypervariable region 1 in patients chronically infected with hepatitis C virus genotype 2.

The hypervariable region 1 (HVR1) has been most reliably identified in the genome of HCV genotype 1 isolates and thought to possibly play a role in immune evasion and development of chronic infection. There are few studies, however, of other HCV genotypes to determine if they also have such a hypervariable region present, and it is unclear whether or not there is any genotype-dependent difference in the genetic characteristics of HVR1. We determined the nucleotide sequence of 5' end of E2/NS1 region of the HCV genome spanning HVR1 of multiple genotype 1 and 2 HCV isolates and carried out a detailed genetic analysis. Similarity plots identified two hypervariable regions within the genotype 2 sequences, a larger one corresponding to HVR1 as well as a smaller 27-nucleotide region of hypervariability. The synonymous substitutions per synonymous site (ds) was greater than nonsynonymous substitutions per nonsynonymous site (dn) within genotype 1 group whereas dn and ds were similar in the genotype 2 group. Analysis of amino acid sequences revealed several conserved sites across genotype 1 and 2 (amino acid numbers 2,6, 20 and 26) and overall similar hydropathic profiles were found within two genotypes. Still, despite the hypervariability, the HVR1 showed a genotype-specific phylogenetic clustering. Thus, HVR1 appears to be conserved between genotypes in keeping with it having an important survival function. Genotype 2 appears to have a greater rate of nonsynonymous substitutions within HVR1, suggesting a greater positive evolutionary pressure.     

Histological difference between complete responders and nonresponders to interferon therapy of the livers of patients with chronic hepatitis C

Liver histology was compared in patients with chronic hepatitis C to note the differences between responders and nonresponders to interferon treatment. Fifty-eight patients were administered interferon in varying doses and over various periods, and were then followed up for 1 year. According to the improvement status of serum alanine aminotransferase (ALT) levels during this period, the patients were classified into complete responders who showed complete normalization of ALT; partial responders who exhibited a significant decrease, but not complete normalization of ALT. Before application of the interferon treatment, liver biopsies were analyzed in four parameters and given scores from 0 to 5 for three groups in cord with no prior knowledge of the efficacy. The parameters included necroinflammation, fibrosis/lobular distortion, portal lymphocytic reaction and portal (or fibrous septal) outline destruction. Results indicated that there were no significant differences in the score of necroinflammation and portal lymphocytic reaction between the complete responder group and the nonresponder group. In contrast, the complete responder group exhibited weaker fibrosis/lobular distortion and less portal outline destruction than the non-responder group. The partial responder group was more akin to the former group in these parameters. Thus, it is safe to conclude that liver histology may predict the efficacy of interferon treatment.     

Iron overload in patients with chronic hepatitis C: A clinicopathologic study

Recent studies suggest that increased hepatic iron may impair the response to interferon therapy in patients with chronic hepatitis C. We reviewed the records and liver biopsies of 72 patients with chronic hepatitis C to determine the prevalence of iron overload and to evaluate whether there is a correlation between serum and hepatic iron concentrations and activity of liver disease. Patients with other causes of liver disease or iron overload were excluded. Necroinflammatory activity and fibrosis were evaluated using modified Knodell score. Hepatic iron was assessed using Brissot's grading system. Increased serum iron and ferritin levels were found in 29% and 43% patients, respectively. Hepatic iron grades 0, I, II, III, and IV were present in 37%, 35%, 25%, 3%, and 0% of patients, respectively. A significant correlation was found between hepatic iron grade and serum ferritin (P = .0001). There was no correlation between hepatic iron grade and histological activity index or fibrosis score. In summary, we found a high proportion of patients with chronic hepatitis C had mild to moderate increase in hepatic iron content even when patients with alcoholism and recurrent transfusions were excluded. However, very few patients had severely increased iron load.     

Clinical characteristics and antibody profiles of chronic hepatitis C patients: Relation to hepatitis C virus genotypes

Genotyping of 179 consecutive Japanese chronic hepatitis C patients was carried out based on the variation in the hepatitis C virus (HCV) core gene. The results were correlated with clinical features and antibody responses toward specific HCV proteins deduced from the nucleotide sequence of genotype I/1 a. Genotypes II/1 b, III/2a, and IV/2b were identified in 138 (77%), 24 (13%), and 12 (7%) patients, respectively. Five patients had double infections. Genotype dependence was observed only for antibody response toward the NS4 (5–1–1) protein, which was infrequent in genotype III/2a patients (33%) compared with genotype II/1 b (81%; P < 0.01) and genotype IV/2b (75%; P < 0.05). Following interferon-α therapy, sustained aminotransferase normalisation was achieved by 89% (eight of nine) patients without antibody to the 5–1–1 protein and 33% (17 of 51) with it (P < 0.01). These findings indicate that absence of antibody response to the 5–1–1 protein is frequent in genotype III/2a HCV carriers and may serve to predict responses to interferon therapy. © 1995 Wiley-Liss, Inc.     

Autoimmune forms of chronic hepatitis associated with hepatitis C virus (HCV) infection with and without HCV-RNA: histological differences from pure autoimmune hepatitis and chronic hepatitis C

Liver biopsy specimens of pure autoimmune hepatitis (pAIH), autoimmune forms of chronic hepatitis with positivity for anti-hepatitis C virus (anti-HCV) and negativity for HCV-RNA (cAIH-RNA(-)), autoimmune forms of chronic hepatitis with positivity for anti-HCV and HCV-RNA (cAIH-RNA(+)), and chronic hepatitis C (CHC) were compared histologically and statistically to clarify the histological character of the autoimmune form of chronic hepatitis with HCV infection. The following representative histological features were used to investigate: inflammation, fibrosis, plasma cell infiltration, lymphoid aggregates/follicles, non-suppurative destructive cholangitis, and the shape of the enlarged portal tracts. While a considerable overlap in histological features between the pAIH and cAIH-RNA(-) groups and between the CHC and cAIH-RNA(+) groups was recognized, the overlap between the pAIH and CHC groups was small. Significant differences were found between cAIH-RNA(-) and cAIH-RAN(+) groups, especially in necroinflammatory findings. In conclusion, most cases of cAIH-RNA(-) with histological features similar to those of pAIH were shown to be AIH. The remaining cases might be CHC with subsidence of viral duplication. Conversely, many cases of cAIH-RNA(+) with histological findings similar to those of CHC were shown to be CHC clinically mimicking pAIH. The remaining cases might represent coexistence of pAIH and HCV infection.     

Distribution of hepatitis B virus in the liver of chronic hepatitis C patients with occult hepatitis B virus infection

Although occult hepatitis B virus (HBV) infection (HBV-DNA in serum in the absence of hepatitis B surface antigen [HBsAg]) is common in chronic hepatitis C, its characteristics are not well known. In this work, the presence of HBV-DNA (by polymerase chain reaction; PCR) and its distribution (by in situ hybridization) in liver biopsies and peripheral blood mononuclear cells (PBMCs) from 32 patients with chronic hepatitis C and occult HBV infection and in 20 HBsAg chronic carriers were determined. The results showed that serum HBV-DNA levels were statistically lower (P = 0.001) in patients with occult HBV infection than in HBsAg chronic carriers. The HBV infection pattern in liver cells was identical between patients with occult HBV infection and those with chronic hepatitis B. However, the mean percentage of HBV-infected hepatocytes was significantly lower (P = 0.001) in patients with occult HBV infection (5 +/- 4.44%) than in HBsAg chronic carriers (17.99 +/- 11.58%). All patients with chronic hepatitis B have HBV-DNA in their PBMCs while this occurred in 50% of the cases with occult HBV infection. In conclusion, patients with occult HBV infection have a low number of HBV-infected hepatocytes and this fact could explain the lack of HBsAg detection and low viremia levels found in these cases.     

GB virus C (GBV-C) infection in patients with chronic hepatitis C. Influence on liver disease and on hepatitis virus behaviour: Effect of interferon alfa therapy

The aim of this study was to evaluate, in patients with chronic hepatitis C, 1) the prevalence and the epidemiological characteristics of GB virus C (GBV-C) infection, 2) the influence of GBV-C on hepatitis C virus (HCV) infection, 3) the pathogenicity of GBV-C in the absence of treatment and under interferon therapy, and 4) the effect of interferon alfa on GBV-C and HCV replications. One hundred fifteen patients with chronic hepatitis C were studied. Before treatment, they were tested for GBV-C RNA by PCR and GBV-C genotype was determined for positive samples. Pretreatment information was collected, including age, gender, source of HCV, estimated duration of HCV infection, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score on liver biopsy, HCV genotype, HCV viral burden and anti-HCV core IgM antibodies. The genetic complexity of the hypervariable region 1 (HVR1) of HCV was studied by PCR-Single Strand Conformation Polymorphism. All patients were treated with 3 to 9 mega units of interferon alfa-2a three times per week for 3 to 6 months. The influence of GBV-C on the evolution of ALT and HCV replication during and after treatment was studied, and GBV-C and HCV RNA were monitored monthly by PCR during this period. Eighteen patients (16%) were GBV-C RNA-positive. Among 11 samples studied, GBV-C genotype 2a was present in 9 cases, 2b in one case and type 3 in one case. GBV-C RNA-positive patients were significantly younger than GBV-C RNA-negative ones (38.4 ± 11.5 vs. 47.4 ± 14.0, P = 0.012), a result independent of the route of transmission and the disease duration. No difference between GBV-C RNA-positive and -negative patients was found for other epidemiological parameters (e.g. gender, risk factor for parenteral viral infections, disease duration and HCV genotypes), or for the characteristics of HCV infection and related liver disease (e.g. HCV RNA level, genetic complexity of the HVR1, anti-HCV core IgM, alanine aminotransferase and gamma-glutamyl transpeptidase activities, cirrhosis and Knodell's score). GBV-C did not influence the rates of ALT normalization at months 3, 6 and 12 and of sustained hepatitis C virological response at month 12 of treatment follow-up. During treatment, GBV-C viremia became undetectable in 12 patients (67%) but relapse occurred after treatment withdrawal in all the nine patients with sufficient follow-up. In the remaining six patients (33%), GBV-C resisted interferon. Whatever the effect of interferon on GBV-C replication, the ALT levels correlated with the presence of HCV RNA. In conclusion, GBV-C infection is frequent in patients with chronic hepatitis C, who are mainly, but not exclusively, infected by GBV-C genotype 2a. GBV-C positive patients are significantly younger than GBV-C negative ones. GBV-C does not seem to affect HCV replication, liver disease and responses of HCV infection and liver disease to interferon therapy. GBV-C is sensitive to 3 mega units of interferon alfa administered three times per week in two-thirds of the patients, but relapse is constant with this dosage after treatment withdrawal. J. Med. Virol. 54:26–37, 1998. © 1998 Wiley-Liss, Inc.     

Sequence evolution and cross-reactive antibody responses to hypervariable region 1 in acute hepatitis C virus infection

Hepatitis C virus (HCV) infection may result in acute resolving or chronic infection. Patients that clear the infection have a more vigorous cellular immune response and an early humoral response to the hypervariable region 1 (HVR1) of the E2 envelope protein. To analyse further the properties of the early anti-HVR1 response, cross-reactivity of anti-HVR1 responses was assessed in five patients with acute HCV infection, who were infected by the same virus strain during a nosocomial outbreak. The sequence evolution of HVR1 was examined in sequential serum samples up to 37 months post infection. Peptides were synthesised corresponding to the obtained HVR1 sequences and unrelated HVR1 sequences, and antibody reactivity to the peptides in sequential sera was investigated by ELISA. The results suggest an association between specific gaps in humoral immunity and the HVR1 sequence evolution during early infection. Possible interpretations of this phenomenon include immune escape mechanisms or suppression of specific anti-HVR1 antibodies.     

对中国人群中III/2a型HCV高变区1序列变异规律的横断研究

目的研究中国丙型肝炎患者III/2a型丙型肝炎病毒(HCV)包膜蛋白E2/NS1高变区1(HVR1)序列变异的规律及意义。方法应用逆转录巢式PCR技术,从38例III/2a型HCV感染患者血清中 ,扩增HCV部分包膜区基因片断(nt1460～1582,HCV J6),纯化后直接采用双脱氧链末端终止法进行序列分析。结果本组III/2a型HCVHVR1位于氨基酸(aa)384～408位,与有关文献报道的结果(383～410或414位)略有差异。与HCV J ,河北株、HCV 1和HCV J6相应序列比较 ,核苷酸(nt)的同源性依次为 :32 %～56 %(平均45.4 %) ,41.7 %～60.0 %(50.7 %) ,41.3 %～62.7 %(53.3 %)和49.3 %～73.3 %(58.9 %) ;aa的同源性依次为 :16 %～48 %(33.5 %) ,28 %～60 %(42.5 %) ,24 %～64 %(45.3 %)和20 %～64 %(39.4 %)。我们在本组HVR1内发现 ,5个较保守的aa位点:385位为Thr,389 ,390和406位为Gly,403位为Phe,其中390位未见于其它报道。结论本组序列变异集中于aa384～408位 ,且以异义替换为主 ,构成了免疫逃逸的基础 ,但某些位点上序列相对保守,这些位点可能是HCV抗原表位的结构位点。对HVR1序列变异规律及其生物学意义的进一步研究 ,将有助于了解HCV的致病机制及疫苗的研制。