Assessment of hepatitis C virus RNA levels by quantitative competitive RNA polymerase chain reaction: high-titer viremia correlates with advanced stage of disease

Increased early acute cellular rejection events in hepatitis C-positive heart transplantation

BACKGROUND

Increased utilization of hepatitis C virus (HCV)-positive donors has increased transplantation rates. However, high levels of viremia have been documented in recipients of viremic donors. There is a knowledge gap in how transient viremia may impact acute cellular rejections (ACRs).

METHODS

In this study, 50 subjects received hearts from either viremic or non-viremic donors. The recipients of viremic donors were classified as nucleic acid amplification testing (NAT)+ group, and the remaining were classified as NAT-. All patients were monitored for viremia levels. Endomyocardial biopsies were performed through 180 days, evaluating the incidence of ACRs.

RESULTS

A total of 50 HCV-naive recipients received hearts between 2018 and 2019. A total of 22 patients (44%) who received transplants from viremic donors developed viremia at a mean period of 7.2 ± 0.2 days. At that time, glecaprevir/pibrentasvir was initiated. In the viremia period (<56 days), 14 of 22 NAT+ recipients (64%) had ACR vs 5 of 28 NAT- group (18%) (p = 0.001). Through 180 days, 17 of 22 NAT+ recipients (77%) had a repeat rejection biopsy vs 12 of 28 NAT- recipients (43%) (p = 0.02). NAT+ biopsies demonstrated disparity of ACR distribution: negative, low-grade, and high-grade ACR in 84%, 12%, and 4%, respectively, vs 96%, 3%, and 1%, respectively, in the NAT- group (p = 0.03). The median time to first event was 26 (interquartile range [IQR]: 8-45) in the NAT+ group vs 65 (IQR: 44-84) days in the NAT-. Time to first event risk model revealed that NAT+ recipients had a significantly higher rate of ACR occurrences, adjusting for demographics (p = 0.004).

CONCLUSIONS

Transient levels of viremia contributed to higher rates and severity of ACRs. Further investigation into the mechanisms of early immune activation in NAT+ recipients is required.

Genotype distribution in relation to viral load in a large cohort of Indian patients with chronic hepatitis C virus infection: A retrospective analysis

INTRODUCTION

Hepatitis C virus (HCV) displays high genetic diversity, characterized by regional variations in the prevalence of genotype posing challenges to the development of vaccines and definitive treatment. Very few reports exist on the distribution and frequency change of HCV genotypes in India. In the present retrospective study, we aimed to understand the distribution pattern of HCV genotypes and viral load among HCV-infected patients attending the Asian Institute of Gastroenterology, Hyderabad, India, a tertiary care hospital.

METHODS

Patients referred to the Hepatology Department from January 2009 to December 2015 were screened for this study. Eight hundred and sixty-two chronic HCV patients were included in this study. Genotyping was performed using type-specific probe-based hybridization assay and viral load was estimated by real-time polymerase chain reaction.

RESULTS

Out of 862 patients, genotype 1 was detected predominantly in 392 (45.5%), followed by genotype 3 in 344 (39.9%) patients; genotypes 4, 6, and 2 were detected in 115 (13.3%), 8 (0.9%), and 3 (0.3%) patients, respectively. The number of patients having genotype 1 increased in frequency while genotype 3 became less from the year 2009 to 2015. Patients having genotype 1 had significantly (p < 0.0001) higher viral load compared with the patients infected with other genotypes.

CONCLUSION

Our study results demonstrate a change in HCV genotypic distribution pattern from genotypes 3 to 1 during the span of 7 years in patients referred to our hospital. In the light of the reported difference in the pathogenic potential of various HCV genotypes, detection of HCV genotype appears to be still essential for better patient management.

Glomerular Diseases Associated With Hepatitis B and C

Infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are prevalent worldwide. In this review, we discuss the epidemiology, pathogenesis, clinical manifestations, and treatment of HBV- and HCV-related glomerulonephritis (GN). The most common histopathologic presentation of HBV-GN is HBV-associated membranous nephropathy, which usually manifests clinically with varying grades of proteinuria and microscopic hematuria. The pathogenesis is likely to be immune complex mediated; however, other host and viral factors have been implicated. The treatment of HBV-GN revolves around antiviral therapy. Various histologic types of glomerular diseases are reported in association with HCV infection, the most frequent being Type 1 membranoproliferative glomerulonephritis, usually in the context of Type 2 mixed cryoglobulinemia. The pathogenesis of HCV-GN can be attributed to glomerular deposition of cryoglobulins or noncryoglobulin-immune complexes. Cryoglobulins typically comprised immunoglobulin Mκ with rheumatoid factor activity. Clinically, patients may present with proteinuria, microscopic hematuria, hypertension, and acute nephritic and/or nephrotic syndrome. The treatment of HCV-GN, especially cryoglobulinemic membranoproliferative glomerulonephritis, encompasses various options including contemporary antiviral therapy with or without conventional and novel immunomodulatory agents.

Hepatic decompensation in antiretroviral-treated patients co-infected with HIV and hepatitis C virus compared with hepatitis C virus-monoinfected patients: a cohort study

BACKGROUND

The incidence and determinants of hepatic decompensation have been incompletely examined among patients co-infected with HIV and hepatitis C virus (HCV) in the antiretroviral therapy (ART) era, and few studies have compared outcome rates with those of patients with chronic HCV alone.

OBJECTIVE

To compare the incidence of hepatic decompensation between antiretroviral-treated patients co-infected with HIV and HCV and HCV-monoinfected patients and to evaluate factors associated with decompensation among co-infected patients receiving ART.

DESIGN

Retrospective cohort study.

SETTING

Veterans Health Administration.

PATIENTS

4280 co-infected patients who initiated ART and 6079 HCV-monoinfected patients receiving care between 1997 and 2010. All patients had detectable HCV RNA and were HCV treatment-naive.

MEASUREMENTS

Incident hepatic decompensation, determined by diagnoses of ascites, spontaneous bacterial peritonitis, or esophageal variceal hemorrhage.

RESULTS

The incidence of hepatic decompensation was greater among co-infected than monoinfected patients (7.4% vs. 4.8% at 10 years; P < 0.001). Compared with HCV-monoinfected patients, co-infected patients had a higher rate of hepatic decompensation (hazard ratio [HR] accounting for competing risks, 1.56 [95% CI, 1.31 to 1.86]). Co-infected patients who maintained HIV RNA levels less than 1000 copies/mL still had higher rates of decompensation than HCV-monoinfected patients (HR, 1.44 [CI, 1.05 to 1.99]). Baseline advanced hepatic fibrosis (FIB-4 score >3.25) (HR, 5.45 [CI, 3.79 to 7.84]), baseline hemoglobin level less than 100 g/L (HR, 2.24 [CI, 1.20 to 4.20]), diabetes mellitus (HR, 1.88 [CI, 1.38 to 2.56]), and nonblack race (HR, 2.12 [CI, 1.65 to 2.72]) were each associated with higher rates of decompensation among co-infected patients.

LIMITATION

Observational study of predominantly male patients.

CONCLUSION

Despite receiving ART, patients co-infected with HIV and HCV had higher rates of hepatic decompensation than HCV-monoinfected patients. Rates of decompensation were higher for co-infected patients with advanced liver fibrosis, severe anemia, diabetes, and nonblack race.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Novel single-step multiplex real-time polymerase chain reaction assay for simultaneous quantification of hepatitis virus A, B, C, and E in serum

BACKGROUND AND AIM

Viral hepatitis needs an earliest diagnosis for its proper and timely treatment. Although serodiagnosis of viral hepatitis is in regular practice, however, it has certain limitations and points to alternate procedures of diagnosis. Present study was designed to develop a single-step multiplex real-time polymerase chain reaction (PCR) assay for detection of hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis E virus (HEV) related nucleic acids in sera from infected patients.

METHODS

The PCR was standardized to detect HAV, HBV, HCV and HEV in serum using variables including annealing temperature, extension temperature, MgCl2 , and primer concentrations. The conserved regions of all viral genomes were used as targets for amplification.

RESULTS

This novel assay was found to be a fast, sensitive, specific, and reproducible system for detection of HAV, HBV, HCV, and HEV in serum. The detection limit for different viral genomes at 100% level was found to be 280 copies/mL for HAV, 290 copies/mL for HBV, 30 copies/mL for HCV, and 300 copies/mL for HEV in a single-tube assay system.

CONCLUSION

Present multiplex real-time PCR is the first report on single-step nucleic acid detection of HAV, HBV, HCV, and HEV in sera samples. It is an alternate diagnostic assay for common use in laboratories analyzing viral hepatitis cases.

Role of viral genotypes and hepatitis B viral mutants in the risk of hepatocellular carcinoma associated with hepatitis B and C dual infection

BACKGROUND/AIMS

The independent and interactive effects of hepatitis B virus (HBV) and hepatitis C virus (HCV) factors on the development of hepatocellular carcinoma (HCC) in chronic HBV/HCV dually-infected patients remain unclear.

METHODS

In a cross-sectional and case-controlled study, the HBV and HCV loads and genotypes and the sequences of pre-S and precore/core promoter regions were determined in 146 HCC patients and 167 chronic carriers with HBV/HCV dual infection.

RESULTS

Age (odds ratio (OR) 1.1), male sex (OR 2.3), pre-S deletion (OR 5.0), A1762T/G1764A mutant (OR 2.5), HCV genotype-1 (OR 2.4) and platelet count <15 × 10(4)/μl (OR 1.9) were independently associated with HCC by stepwise logistic regression analysis. Patients with combined HBV mutations (pre-S deletion and A1762T/G1764A mutant) and HCV genotype-1 had a 39-fold increased risk of developing HCC compared to those with A1762T/G1764A and pre-S wild-type strains and HCV genotype non-1. In the nested case-control study, patients with HCC had a higher HBV DNA level (p < 0.001), a higher frequency of pre-S deletion (p < 0.001) and A1762T/G1764A mutant (p = 0.005), a lower HCV RNA level (p = 0.012) and a higher prevalence of HCV genotype-1 (p = 0.002) than those without.

CONCLUSIONS

Pre-S deletion, A1762T/G1764A mutation and HCV genotype-1 are important in hepatocarcinogenesis in chronic HBV/HCV dual infection.

Effect of human leukocyte antigen class I and II alleles on hepatitis C viral load among chronic hepatitis C patients in Southern Taiwan

The viral load of hepatitis C virus (HCV) in chronic hepatitis C patients affects clinical outcomes and response to interferon treatment. Various factors may be involved in determining the viral load, including host genetic factors. The aim of this study was to investigate the relationship between HCV viral load and human leukocyte antigen (HLA) class I and class II alleles. One hundred and six HCV RNA positive subjects were enrolled, and viral load was measured. HLA-A, -B, -C, -DR, and -DQ loci were determined by sequence-based genotyping. Univariate analysis indicated that HLA-B(*)40 and HLA-C(*)07 alleles had significantly higher HCV RNA levels (P<0.05). Patients with the HLA-C(*)15 allele exhibited a trend toward a lower HCV viral load (P=0.06). After controlling for confounding factors, multivariate analysis revealed that only HLA-C(*)15 allele was identified as a significant determinant for HCV-RNA level (slope=-0.91, 95% CI: -1.58, -0.24; Holm's P<0.01). Patients expressing the HLA-C(*)15 allele had significantly lower HCV RNA levels. HCV genotype 1 was significantly associated with high HCV RNA levels (P<0.05 by Mann-Whitney U test). In conclusion, HLA-C(*)15 is an important host immunogenetic factor with an inverse association to HCV viral load in CHC patients in Taiwan. HCV genotype 1 is the viral factor that associated with high viral load.

Long-term follow-up and outcome of liver transplantation from anti-hepatitis C virus-positive donors: a European multicentric case-control study

BACKGROUND

The growing prevalence of hepatitis C virus (HCV) infection in the general population has resulted in an increased frequency of potential organ donors that carry the virus. Given the significant disparity between organ supply and demand for transplantation, it becomes essential to consider whether livers from anti-HCV-positive donors may be considered suitable for transplantation.

METHODS

Based on a multicenter European database, 694 patients with HCV-related cirrhosis underwent liver transplantation and 11% of them received the graft from anti-HCV-positive donors. Of this group, we selected 63 patients (study group) and, after a 1:1 case-control approach, compared them with 63 patients that received an anti-HCV-negative donor graft (control group). Only grafts with preperfusion liver biopsy results with a fibrosis score of not more than 1 were used for transplantation.

RESULTS

Patients who received anti-HCV-positive grafts had a cumulative survival rate of 83.6% and 61.7% at 1 and 5 years, respectively, vs. 95.1% and 68.2% for the control group. In comparing overall patient and graft survival, there was no statistically significant difference between the two groups (P=0.22 and 0.11). Recurrence of hepatitis C tended to be more rapid in the group of patients who received anti-HCV-positive grafts, although it did not reach statistical significance (P=0.07).

CONCLUSIONS

We do not recommend the indiscriminate use of anti-HCV-positive donors, especially if HCV-RNA positive, as the use of this kind of graft could be linked to an advanced stage of fibrosis, the main risk factor we observed for earlier hepatitis C recurrence.

Virological rather than host factors are associated with transaminase levels among HIV/HCV-coinfected patients

Alanine aminotransferase (ALT) is a routine parameter in the assessment and monitoring of chronic hepatitis C viral (HCV) infection. Hepatitis C virus-infected African Americans (AAs) have been reported to have lower ALT levels. In this retrospective, cross-sectional, multicenter study, host and virological factors possibly associated with ALT levels were analyzed by multivariate regression analyses among HIV/HCV-coinfected patients. Of the 289 patients included, 142 were African Americans and 144 Caucasians. In multivariate analysis, only HCV genotype 3 (B 0.2 [95% CI 13.39-52.33]; P = .001) and HCV RNA >500 000 IU/mL (B 3.1 [95% CI 7.67-34.75]; P = .002) were independent predictors of higher ALT levels. Per the American Association for the Study of Liver Disease (AASLD) definition, 18.2% had ALT levels within normal limits. Male sex and HCV RNA <500 000 IU/mL predicted ALT within normal limits. Hepatitis C viral factors rather than race were associated with ALT levels in this HIV/HCV-coinfected population. ALT were within normal limits in 18% of patients, who more often were male and had lower Hepatitis C viral load.

Correlates of high hepatitis C virus RNA load in a cohort of HIV-negative and HIV-positive individuals with haemophilia

Hepatitis C virus (HCV) treatment failure and disease progression are more likely with high HCV-RNA load. Correlates of high HCV-RNA load in individuals with haemophilia are largely unknown. Among 1266 interferon naïve HCV-infected individuals with haemophilia, we compared those with high (> 2 x 10⁶ HCV-RNA copies/mL) to lower viral load, overall and stratifying on HIV co-infection status using logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). Overall, high HCV load was independently associated with longer duration of HCV infection (P(trend)=0.0001), body mass index ≥ 25 kg/m² (OR=1.4, 95% CI=1.1-1.9), and HIV co-infection (OR=1.4, 95% CI=1.0-1.8). Among 795 HIV-negative participants, high HCV-RNA load was associated with older age at HCV acquisition (OR=1.9 for > 15 years vs ≤ 2 years, P(trend)=0.008), and lower AST/platelet ratio (P(trend)=0.01), in addition to longer duration of HCV infection (P(trend)=0.0008), and body mass index ≥ 25 kg/m² (OR=1.6, P=0.005). Among 471 HIV-positive individuals, anti-retroviral therapy (ART) was the only variable associated with high HCV-RNA load (OR=1.8, CI=1.1-2.9 for combination ART; OR=1.8, CI=0.9-3.4, for other ART vs no treatment). High HCV-RNA load with haemophilia is more likely with longer duration of infection, older age at infection, higher body mass index, and antiretroviral therapy. These findings may help identify individuals at increased risk of HCV treatment failure and progression to end-stage liver disease.

Ethanol enhances hepatitis C virus replication through lipid metabolism and elevated NADH/NAD+

Ethanol has been suggested to elevate HCV titer in patients and to increase HCV RNA in replicon cells, suggesting that HCV replication is increased in the presence and absence of the complete viral replication cycle, but the mechanisms remain unclear. In this study, we use Huh7 human hepatoma cells that naturally express comparable levels of CYP2E1 as human liver to demonstrate that ethanol, at subtoxic and physiologically relevant concentrations, enhances complete HCV replication. The viral RNA genome replication is affected for both genotypes 2a and 1b. Acetaldehyde, a major product of ethanol metabolism, likewise enhances HCV replication at physiological concentrations. The potentiation of HCV replication by ethanol is suppressed by inhibiting CYP2E1 or aldehyde dehydrogenase and requires an elevated NADH/NAD(+) ratio. In addition, acetate, isopropyl alcohol, and concentrations of acetone that occur in diabetics enhance HCV replication with corresponding increases in the NADH/NAD(+). Furthermore, inhibiting the host mevalonate pathway with lovastatin or fluvastatin and fatty acid synthesis with 5-(tetradecyloxy)-2-furoic acid or cerulenin significantly attenuates the enhancement of HCV replication by ethanol, acetaldehyde, acetone, as well as acetate, whereas inhibiting beta-oxidation with beta-mercaptopropionic acid increases HCV replication. Ethanol, acetaldehyde, acetone, and acetate increase the total intracellular cholesterol content, which is attenuated with lovastatin. In contrast, both endogenous and exogenous ROS suppress the replication of HCV genotype 2a, as previously shown with genotype 1b.

CONCLUSION

Therefore, lipid metabolism and alteration of cellular NADH/NAD(+) ratio are likely to play a critical role in the potentiation of HCV replication by ethanol rather than oxidative stress.

Serum HCV-RNA levels in patients with chronic hepatitis C: Correlation with histological features

BACKGROUND AND STUDY AIMS

Liver disease in chronic hepatitis C virus (HCV) infection ranges from minimal lesion to liver cirrhosis and sometimes eventually evolving hepatocellular carcinoma. Whether and how HCV determines the different clinical and histological manifestation of the disease is not fully understood. It has not been clearly elucidated whether the extent of liver injury induced by HCV is influenced mainly by direct cytopathic damage or by an immune-mediated response against HCV-infected hepatocytes. The aim of this study is to verify whether the amount of virus in individual patient's serum could be related to the severity of liver injury.

PATIENTS AND METHODS

This study was carried out in the Gastroenterology and Hepatology Teaching Hospital, Medical City, Baghdad. Serum levels of HCV-RNA were measured in 27 patients with chronic HCV using b-DNA assay. Core liver biopsies of the patients were evaluated according to Ishak histological activity index system.

RESULTS

The serum HCV RNA concentrations in the patients ranged from 3.2×10(3) to 1.2×10(7)copies/ml. In all patients no correlation was observed between the variable levels of viraemia and the age of the patients. Furthermore no correlations were observed between the serum HCV RNA concentrations and the biochemical liver function test levels: Total serum bilirubin, AST, ALT, and alkaline phosphatase. Histologically; patients were categorized into four subgroups: four patients (14.8%) had minimal activity, 17 patients (63%) had mild activity, and six patients (22.2%) had moderate activity. No significant correlation was found between viraemic levels and these histological findings or their individual components: Interface hepatitis, confluent necrosis, intralobular liver cell necrosis and portal inflammation. According to the stage of the fibrosis, the patients were categorized into seven subgroups: one patient (3.7%) with stage zero, seven patients with stage one (25.9%), four patients with stage two (14.9%), eight patients with stage three (29.6%), three patients with stage four (11.1%), two patients with stage five (7.4%), and two patients in cirrhotic stage six (7.4%). There was no correlation between the serum HCV RNA concentration and the stage of fibrosis. Hepatic steatosis was observed in 16/27 patients. It was mild in nine patients, moderate in five patients, and severe in two patients. Correlation has not been observed between the serum HCV RNA viraemic level and the severity of steatosis.

CONCLUSION

Serum HCV-RNA level does not determine the degree of hepatic injury precisely and liver biopsy is necessary to accurately evaluate the extent of liver damage.

Association of amino acid variations in the NS5A and E2-PePHD region of hepatitis C virus 1b with hepatocellular carcinoma

NS5A and E2 proteins of the hepatitis C virus (HCV) have the potential to repress protein kinase R (PKR) that exerts a tumour suppressor function. We investigated the relationship between amino acid variations in the NS5A-PKR-binding domain and E2-PKR-eIF2alpha phosphorylation homology domain (PePHD) region and the development of hepatocellular carcinoma (HCC) in chronic HCV-1b patients. In a cross-sectional, hospital-based setting, we compared the amino acid sequences of NS5A-PKR-binding domain and E2-PePHD in the sera of 104 chronic hepatitis, 44 cirrhosis and 96 HCC patients. The nucleotide sequences were inferred by direct sequencing of the amplified HCV products and deduced amino acid were compared with the sequence of HCV-J. By univariate analysis, old age, lower viral load, fewer amino acid substitutions in the NS5A-PKR-binding domain (codons 2209-2274) and the interferon sensitivity-determining region (ISDR; codons 2209-2248), and wild-type amino acid at codon 2209 and codon 2240 was significantly correlated with HCC, whereas substitutions in the E2-PePHD was not. Patients with a mutated-type (> or = 4) NS5A-ISDR had a lower prevalence of HCC than those with intermediate or wild type (P < 0.05). Based on stepwise logistic regression analysis, age [odds ratio (OR): 1.132, P < 0.001], viral load (OR: 0.305, P < 0.001) and mutated-type ISDR (OR: 0.137, P = 0.001) were independently associated with HCC. In conclusion, NS5A-ISDR variations may play an important role in the development of HCV-related HCC.

Influence of Donor Histology on Outcome in Patients Undergoing Transplantation for Hepatitis C

BACKGROUND

Risk factors for graft loss and recipient death in liver transplantation for hepatitis C virus (HCV) have been extensively investigated. Donor age was defined as one of the most important predictors of outcome in these patients; however, the mechanism leading to more severe recurrent hepatitis has not yet been investigated.

METHOD

In a retrospective analysis, histological findings of 79 donor liver grafts were assessed according to criteria inflammation, fibrosis, fatty degeneration, and necrosis. These findings were correlated with the histological and clinical course of HCV-positive liver graft recipients.

RESULTS

The overall 1-, 5- and 10-year graft survival figures were 85%, 77%, and 60%, respectively. We could not identify any correlation between outcome, fat content, and necrosis in the donor liver. However, stage 3 and 4 fibrosis 1 year after liver transplantation was significantly increased in the group of patients receiving a graft from a donor with portal inflammation (P<0.05). Additionally, the occurrence of intrahepatic inflammation was significantly increased in older donors (P<0.05) and donors with prolonged intensive care hospitalization (P<0.05).

CONCLUSION

A number of risk factors for detrimental outcome in HCV-positive patients after liver transplantation have been identified. In particular, older donor age significantly impaired outcome in recent analysis, but due to donor shortage it is not possible to provide young grafts for all HCV-positive patients. Our data show that donor histology is helpful in identifying patients with more severe recurrent hepatitis prior to transplantation, and that especially in older donors, prolonged intensive care hospitalization should be avoided.

A prospective evaluation of fibrosis progression in patients with recurrent hepatitis C virus following liver transplantation

Recurrence of hepatitis C virus (HCV) following liver transplantation (LT) is universal. A subset of these patients develop advanced fibrosis and cirrhosis and it is believed that this leads to increased posttransplantation mortality. The specific aims of this study were to determine the incidence of advanced fibrosis and those factors associated with this process, and to evaluate causes for mortality in patients with recurrent HCV. A total of 227 patients who underwent LT with chronic HCV were monitored prospectively. The mean age of this group at LT was 49.5 yr; 76% were male and 85% were Caucasian. Fibrosis progression was monitored by protocol liver biopsy, initially performed 6 months after LT and then at 6- to 24-month intervals. Advanced fibrosis, defined as the bridging fibrosis or cirrhosis, developed in 1%, 11%, 25%, and 41% of patients after 1, 3, 5, and 6-10 yr, respectively. Acute cellular rejection hepatic steatosis, a persistent elevation in serum alanine aminotransferase and donor-race were associated with the development of advanced fibrosis. In contrast, the development of advanced fibrosis was not affected by the use of interferon prior to undergoing LT, cytomegalovirus disease, or donor age. A total of 60 patients (26%) died over 15 yr of follow-up. Although graft failure accounted for 45% of deaths in patients with advanced fibrosis, this represented only 8% of all deaths in patients with recurrent HCV. Sepsis was the most common cause of death and this was observed with similar frequency in patients who developed advanced fibrosis (45%) and in those with less advanced fibrosis (47%). In conclusion, approximately 41% of patients with recurrent HCV developed advanced fibrosis 6-10 yr after LT. However, complications associated with sepsis, not recurrent cirrhosis, was the most common cause of death in patients with recurrent HCV and this was similar in patients with or without advanced fibrosis.

Factors affecting serum concentrations of hepatitis C virus (HCV) RNA in HCV genotype 1-infected patients with chronic hepatitis

The serum concentration of hepatitis C virus (HCV) RNA is usually stable (4 to 8 log(10) IU/ml) in untreated patients with chronic hepatitis C. While this baseline HCV RNA concentration ([HCV RNA](BL)) is predictive of a sustained virologic response to treatment, its determinants are only partially identified. We therefore analyzed the baseline characteristics of 2,472 HCV genotype 1-infected patients to identify correlations with gender, age, race, weight, body mass index (BMI), HCV acquisition mode, HCV subtype, alanine aminotransferase concentration, or histopathologic changes in the liver. After separation of the data according to four [HCV RNA](BL) groups (< or =5.0, >5.0 to 5.6, >5.6 to 5.9, and >5.9 log(10) IU/ml), we determined that increasing [HCV RNA](BL) correlated (P < 0.05) with increasing proportions of patients who were male, >40 years of age, or heavier (a weight of >85 kg or a BMI of >27 kg/m(2)). Histologic activity index (HAI) data were available for 1,304 of these patients: increasing [HCV RNA](BL) correlated with higher fibrosis and necrosis-inflammation scores. As a continuous variable, [HCV RNA](BL) correlated with age, gender, weight (continuous or < or =85 versus >85 kg), BMI (continuous or < or =27 versus >27 kg/m(2)), subtype, fibrosis score, and necrosis-inflammation score; however, multiple-regression analysis yielded P values of <0.1 only for age, gender, BMI (< or =27 versus >27 kg/m(2)), and fibrosis score. While our findings are suggestive of a role for these factors in maintenance of the pretreatment state of HCV infection, the multiple-regression model accounted for only < or =4.6% of the [HCV RNA](BL) differences between individuals (R(2) = 0.046 for 1,304 patients with HAI scores; 0.043 for all 2,472 patients).

Infectious Agents

There is substantial evidence that infectious agents play a causal role in a variety of human malignancies. These cancers include the liver, cervix, stomach, nasopharynx, bladder, and bile duct as well as Kaposi sarcoma (KS) and several lymphomas. This chapter summarizes the biological and epidemiologic features of each of the major oncogenic infections, beginning with the viruses, followed by H. pylori, and with a brief summary of the relevant parasites.

Real-time quantitative assay of HCV RNA using the duplex scorpion primer

A novel real-time quantitative method for detecting HCV in serum was established in which the duplex scorpion primer was used to provide a unimolecular probing mechanism for hybridizing the highly conserved 5' noncoding region (5' NCR) of the HCV genome specifically. Through methodological evaluation, we found this new method had a wide linearity, high sensitivity, repeatability and specificity. Compared to the commercial TaqMan method, this method was found to be more sensitive and less costly, and the final results were obtained more quickly. Therefore, it could be applied to diagnose and monitor HCV infection in clinical practice.

Hepatitis C virus genotypes in southern Taiwan: prevalence and clinical implications

The role of hepatitis C virus (HCV) genotypes in the development of hepatocellular carcinoma (HCC) is still controversial. To determine the distribution and clinical implications of HCV genotypes in southern Taiwan, we analysed 418 patients with chronic HCV infections. HCV genotypes were determined using an HCV Line Probe Assay. The predominant HCV genotype was 1b (45.5%), followed by 2a/2c (30.9%) and 2b (6.9%). The prevalence of genotype 1b in HCC patients (60.3%) was significantly higher than in those with liver cirrhosis (38.7%) and chronic hepatitis (38.7%) (P=0.003 and P<0.001, respectively). Patients with chronic HCV 2a/2c infection had higher alanine aminotransferase (ALT) levels than those with chronic HCV 1b infection (P<0.001). Univariate analysis revealed that disease severity was significantly correlated with older age, genotype 1b, lower ALT levels and lower viral load. Based on multiple logistic regression analysis, after adjusting for age and serum HCV RNA levels, HCV 1b infection was still a significant risk factor for HCC. In conclusion, the predominant genotypes in southern Taiwan were 1b and 2a/2c, and disease severity was associated with genotype 1b.

Predictors of hepatitis C virus RNA levels in a prospective cohort study of drug users

High levels of hepatitis C virus (HCV) RNA are associated with a poor response to treatment of chronic hepatitis C, and a substantial reduction in HCV RNA levels predicts a favorable treatment response. We prospectively studied time-dependent and time-independent predictors of HCV RNA levels in 264 drug users with chronic HCV infection. Interviews on medical history and high-risk behaviors, phlebotomy for HIV viral load, serum HCV RNA levels as measured by the COBAS Amplicor HCV Monitor (Roche Diagnostics, Branchburg, NJ), and a lymphocyte subset assay were performed. Factors associated with HCV RNA levels over time were analyzed using a linear mixed model. Nearly 70% of the participants were men, two thirds were Hispanic, and the mean age was 46 years. HCV RNA levels increased over time. Older age (P < 0.001), HIV seropositivity (P = 0.03), and HCV nongenotype 1 (P = 0.05) were predictors of higher HCV RNA levels on multivariate analysis. Among 142 HIV-seropositive participants, a detectable HIV-1 viral load (P < 0.001) and recent alcohol use (P = 0.02) were predictors of higher HCV RNA levels. The predictors of higher HCV RNA levels found in this longitudinal study are consistent with those of prior cross-sectional studies. Further studies are warranted to determine if treatment of alcohol use affects HCV RNA levels.

Recombinant ovine atadenovirus induces a strong and sustained T cell response against the hepatitis C virus NS3 antigen in mice

Ovine atadenovirus (OAdV) is a novel gene transfer vector with excellent in vivo gene transfer characteristics. In the present study, we have investigated the ability of an OAdV vector to mediate a T cell response to an antigen of the hepatitis C virus (HCV) in mice. Specifically, an expression cassette coding for non-structural protein 3 (NS3) of hepatitis C virus was inserted into the OAdV genome and the resulting recombinant virus (OAdV-ns3) was shown to propagate stably and to express the ns3 gene at a high level in vitro. A single injection of this non-replicating vector into BALB/c mice resulted in a strong induction of NS3-specific, IFN-gamma secreting T-lymphocytes as measured by direct ex vivo ELISpot assay. The number of IFN-gamma secreting lymphocytes remained nearly unaltered for a period of at least 10 weeks. The immune response was shown to depend on virus dose but a single intramuscular injection of less than 10(8) infectious particles of OAdV-ns3 was sufficient to induce a significant NS3-specific T cell response. Moreover, this response was not affected by prior immunisation of animals with human adenovirus type 5 (HAdV-5). The results of our study provide proof for the concept that OAdV vectors may be valuable tools for vaccination and immunotherapy even in the face of natural immunity to human adenoviruses.

Correlation of serum aminotransferases with HCV RNA levels and histological findings in patients with chronic hepatitis C: the role of serum aspartate transaminase in the evaluation of disease progression

OBJECTIVES

To investigate whether HCV RNA levels can be considered to be predictors of hepatocellular injury in patients with chronic hepatitis C, and whether aminotransferase levels are markers of liver damage.

METHODS

We performed a retrospective study on 112 patients with chronic hepatitis C. For each patient, we considered the baseline alanine aminotransferase (ALT) and serum aspartate transaminase (AST) levels, baseline HCV RNA, HCV genotype, histological evaluation and the mean aminotransferase levels measured in the 6 months following liver biopsy.

RESULTS

We found a statistically significant correlation between HCV RNA and aminotransferase levels measured during the follow-up (AST: r = 0.24, P = 0.01; ALT: r = 0.27, P = 0.004). We also observed a statistically significant correlation between HCV RNA levels and histological activity index (HAI) (r = 0.25, P = 0.008), as well as between the HAI and both baseline AST (r = 0.34, P = 0.0002) and ALT levels (r = 0.23, P = 0.01). These findings were confirmed by the mean aminotransferase values during follow-up. In the regression analysis, the fibrosis score was significantly and independently associated with baseline AST and ALT values.

CONCLUSIONS

Our results demonstrate a statistically significant correlation of aminotransferase values with the histological parameters, and an even stronger correlation with the AST values. Our study therefore suggests that aminotransferase values, especially AST, may correlate with liver damage.

Dissociation of serum and liver hepatitis C virus RNA levels in patients coinfected with human immunodeficiency virus and treated with antiretroviral drugs

We examined hepatitis C virus (HCV) RNA levels in serum, peripheral blood mononuclear cells (PBMC), and the liver for 135 patients with chronic HCV infections, 44 of whom were human immunodeficiency virus (HIV) positive and treated with highly active antiretroviral therapy (group A), 66 of whom were HIV negative (group B), with abnormal serum alanine aminotransferase (ALT) values, and 25 of whom were HIV negative, with ALT values of </=1.5 times the normal value (group C). Patients had not been treated with interferon, with or without ribavirin, at the time of the study. A statistically significant correlation between HCV RNA levels in the liver and serum was reproducibly documented, whereas this was inconsistent for serum and PBMC. A comparative evaluation of HCV RNA levels in the liver and PBMC showed significantly lower values for group A than for groups B and C (P < 0.01 and P < 0.0001, respectively). In contrast, HCV RNA levels in serum were significantly higher for group A than for group B (P < 0.001). A dissociation between HCV RNA levels in serum and the liver was found for patients with HIV-HCV coinfections. Although the relative contribution of extrahepatic reservoirs, including lymphoid cells, to HCV RNA levels in serum is unclear, it may be speculated that a low intrahepatic HCV burden is caused by restored immunocompetence after successful antiretroviral therapy in coinfected patients.

Comparative evaluation of the total hepatitis C virus core antigen, branched-DNA, and amplicor monitor assays in determining viremia for patients with chronic hepatitis C during interferon plus ribavirin combination therapy

An assay prototype designed to detect and quantify total hepatitis C virus [HCV] core antigen (HCV core Ag) protein in serum and plasma in the presence or absence of anti-HCV antibodies has been recently developed by Ortho-Clinical Diagnostics. The aim of the study was to evaluate the sensitivity, specificity, and reproducibility of the Total HCV core Ag assay in comparison with two quantitative assays for HCV RNA: Quantiplex HCV RNA 2.0 (bDNA v2.0) or Versant HCV RNA 3.0 (bDNA v3.0) assays and the Cobas Amplicor HCV Monitor version 2.0 (HCM v2.0) test. We have studied samples of a well-characterized panel and samples from patients with chronic hepatitis C treated with interferon alone or with ribavirin. We have also compared the kinetics of HCV core Ag and HCV RNA in the follow-up of treated patients. The HCV core Ag assay exhibited linear behavior across samples from different genotypes. The coefficients of variation for intra- and interassay performance were 5.11 and 9.95%, respectively. The specificity of the assay tested in blood donors was 99.5%. Samples from HCV-infected patients showed that the correlation between the HCV core Ag and the two HCV RNA quantitative assays (bDNA and HCM v2.0) was 0.8 and 0.7, respectively. This correlation was maintained across different genotypes of HCV (r(2) = 0.64 to 0.94). Baseline HCV core Ag values were significantly lower in sustained responders to interferon (IFN) than in other groups of patients (5.31 log(10) [10(4) pg/ml] versus 5.99 log(10) [10(4) pg/ml]; P < 0.001). In patients treated with IFN or combination therapy, we found an association between a decrease of more than 2 log IU/ml in viral load, undetectable HCV core Ag, and sustained response. Among sustained responders to IFN alone or combination therapy and among relapsers after IFN alone, 84 out of 101 (83.2%) had undetectable HCV core Ag, and 76 out of 96 (79.2%) had a viral load decrease of >/=2 log IU/ml, after 1 month of treatment. In conclusion, the Total HCV core Ag assay is a new useful test for the detection of HCV viremia and the monitoring of patients treated with IFN alone or in combination with ribavirin.

Predicting progression to cirrhosis in chronic hepatitis C virus infection

A systematic evaluation of published studies was undertaken to identify factors associated with accelerated fibrosis progression in patients with chronic hepatitis C virus (HCV) infection. An ecologic analysis was used to estimate relative risk (RR) of cirrhosis across four study methodologies: liver clinic series, post-transfusion cohorts, community-based studies and blood donor series. In each study category, the following factors were independently associated with disease progression: male sex (RR = 1.08); heavy alcohol consumption (RR = 1.61); elevated serum ALT levels (RR = 1.23) and histology demonstrating high-grade necro-inflammatory activity. After adjusting for these cofactors, older age at HCV infection and acquisition of HCV through blood transfusion were not implicated in influencing disease outcome. Although not able to be examined in this study,co-infection with HIV, and to a lesser extent HBV, is also likely to result in worse outcomes for patients with chronic HCV infection. Virological factors such as HCV genotype, viral load and quasispecies diversity are less likely to be important. A Weibull distribution was used to model disease progression at a population level. The influence of cofactors on individual prognosis was examined and an algorithm to predict the risk of subsequently developing cirrhosis is presented.

Comparative evaluation of the total hepatitis C virus core antigen, branched-DNA, and amplicor monitor assays in determining viremia for patients with chronic hepatitis C during interferon plus ribavirin combination therapy

An assay prototype designed to detect and quantify total hepatitis C virus [HCV] core antigen (HCV core Ag) protein in serum and plasma in the presence or absence of anti-HCV antibodies has been recently developed by Ortho-Clinical Diagnostics. The aim of the study was to evaluate the sensitivity, specificity, and reproducibility of the Total HCV core Ag assay in comparison with two quantitative assays for HCV RNA: Quantiplex HCV RNA 2.0 (bDNA v2.0) or Versant HCV RNA 3.0 (bDNA v3.0) assays and the Cobas Amplicor HCV Monitor version 2.0 (HCM v2.0) test. We have studied samples of a well-characterized panel and samples from patients with chronic hepatitis C treated with interferon alone or with ribavirin. We have also compared the kinetics of HCV core Ag and HCV RNA in the follow-up of treated patients. The HCV core Ag assay exhibited linear behavior across samples from different genotypes. The coefficients of variation for intra- and interassay performance were 5.11 and 9.95%, respectively. The specificity of the assay tested in blood donors was 99.5%. Samples from HCV-infected patients showed that the correlation between the HCV core Ag and the two HCV RNA quantitative assays (bDNA and HCM v2.0) was 0.8 and 0.7, respectively. This correlation was maintained across different genotypes of HCV (r(2) = 0.64 to 0.94). Baseline HCV core Ag values were significantly lower in sustained responders to interferon (IFN) than in other groups of patients (5.31 log(10) [10(4) pg/ml] versus 5.99 log(10) [10(4) pg/ml]; P < 0.001). In patients treated with IFN or combination therapy, we found an association between a decrease of more than 2 log IU/ml in viral load, undetectable HCV core Ag, and sustained response. Among sustained responders to IFN alone or combination therapy and among relapsers after IFN alone, 84 out of 101 (83.2%) had undetectable HCV core Ag, and 76 out of 96 (79.2%) had a viral load decrease of >/=2 log IU/ml, after 1 month of treatment. In conclusion, the Total HCV core Ag assay is a new useful test for the detection of HCV viremia and the monitoring of patients treated with IFN alone or in combination with ribavirin.

Managing occupational risks for hepatitis C transmission in the health care setting

Hepatitis C virus (HCV) infection is a significant contemporary health problem in the United States and elsewhere. Because it is primarily transmitted via blood, hepatitis C infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. Recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupational hepatitis C infections when they occur. This article reviews this developing information. Recently published data demonstrate success rates in the treatment of "acute hepatitis C syndrome" that approach 100\%, and although these studies are not directly applicable to all occupational infections, they may provide important clues to optimal management strategies. In addition, the article delineates approaches to the prevention of occupational exposures and also addresses the difficult issue of managing HCV-infected health care providers. The article summarizes currently available data about the nosocomial epidemiology of HCV infection and the magnitude of risk and discusses several alternatives for managing exposure and infection. No evidence supports the use of immediate postexposure prophylaxis with immunoglobulin, immunomodulators, or antiviral agents. Based on the very limited data available, the watchful waiting and preemptive therapy strategies described in detail in this article represent reasonable interim approaches to the complex problem of managing occupational HCV infections, at least until more definitive data are obtained.

Hepatitis C and alcohol: interactions, outcomes, and implications

BACKGROUND

Alcoholism and chronic hepatitis C (HCV) infection are common causes of liver disease worldwide. Hepatitis C virus and alcohol use frequently coexist, and together lead to more rapid progression of liver disease.

GOALS

To critically review the literature pertaining to the combined effects of alcohol and HCV, focusing primarily on how alcohol influences the natural history, pathogenesis, and treatment of HCV liver disease.

STUDY

A thorough review of the English literature was conducted, using a MEDLINE-based computerized literature search and review of cited references.

RESULTS

Hepatitis C virus is prevalent in unselected alcoholic populations (14-36%) and in alcoholic individuals with liver disease (< or =51%). Hepatitis C virus-infected individuals who drink alcohol in excess have more severe histologic injury, more rapid disease progression, and a higher frequency of cirrhosis and hepatocellular carcinoma. Alcohol use also appears to decrease response rates to interferon therapy. The mechanisms of interaction between alcohol and HCV are not fully understood, but they likely include the effects of alcohol on the host immune system and the virus and on other factors possibly related to HCV liver disease and hepatic carcinogenesis.

CONCLUSIONS

Alcohol use and HCV infection frequently coexist. Although there is ample evidence that alcohol use adversely affects the natural history of HCV liver disease, how the two interact is not well understood. Patients with chronic HCV should be encouraged to avoid alcohol; however, the threshold above which alcohol results in accelerated liver disease remains to be determined.

Viraemia, cryoglobulins and autoantibodies in haemodialysis patients infected with hepatitis C virus

OBJECTIVES

The clinical features of hepatitis C virus (HCV) infection depend on the immune and autoimmune reactions induced by the virus. Chronic renal failure might alter the pattern of these reactions. The aim of this study was to determine the prevalence of cryoglobulinaemia, the frequency of autoantibodies and HCV viral load in HCV infected Greek patients on chronic haemodialysis.

METHODS

Seventy-three HCV Ab(+) patients on maintenance haemodialysis and 87 otherwise normal patients with chronic HCV infection were evaluated for the presence of cryoglobulins, autoantibodies and viral markers.

RESULTS

Cryoglobulins were detected in 22/73 (30.1%) haemodialysis patients and in 23/87 (26.4%) patients with normal renal function (NS). The mean cryocrit value was significantly lower in the haemodialysis group ( = 0.002). Haemodialysis patients had significantly higher levels of C4 component of complement and lower incidence of rheumatoid factor than those of patients with normal renal function. Serum HCV RNA levels were found significantly lower in the haemodialysis group (median, 2.20 Meq/ml; range, 119.9 Meq/ml) than in the group with normal renal function (median, 4.50 Meq/ml; range, 114.9 Meq/ml; = 0.046). The distribution of genotypes was not different between the two groups.

CONCLUSIONS

There are subtle differences in autoimmune features of HCV infection if the patients are also haemodialysed for renal failure. HCV viral load is lower in haemodialysis patients, with no difference in the HCV genotype prevalence. The clinical significance of these findings is unknown.

Current and future hepatitis C virus diagnostic testing: problems and advancements

Serological antibody assays used in hepatitis C virus diagnosis have improved in sensitivity and specificity. However, detection of active viremia or monitoring levels of virus during or after patient treatment is most commonly undertaken using nucleic acid-based technologies. Advancements in diagnostic technologies and implications for managing patients with hepatitis C in various clinical settings are discussed.

Peripheral B-cell CD5 expansion and CD81 overexpression and their association with disease severity and autoimmune markers in chronic hepatitis C virus infection

Hepatitis C virus (HCV) infection is associated with immune-mediated abnormalities and B-cell lymphoproliferation evolving to an overt lymphoma. Recently, CD81 was identified as an HCV receptor on B-lymphocytes, providing a mechanism by which B cells are infected and activated by the virus. In addition, expansion of CD5+ B lymphocytes was described to be associated with various non-HCV related autoimmune disorders. Therefore, we studied the possible role of peripheral B cells CD81 and CD5 over-expression in the development of HCV-related autoimmunity and their association with disease severity in chronic HCV infection. Peripheral B cells CD5 expression and mean fluorescence intensity (MFI) of CD81 were determined in 30 HCV-infected patients, 30 healthy controls and 15 patients with hepatitis B virus infection using fluorescence-activated cell scan (FACS). We have also investigated the association between peripheral CD5 and CD81 B-cell over-expression and markers of autoimmunity and disease severity in patients chronically infected by HCV. CD5+ B-cells were increased in chronic HCV infection (23.2 +/- 7.2%) compared with those of healthy controls (15 +/- 5.5%) (P < 0.0001) and chronic HBV infection (19 +/- 3.7%) (P = 0.08). CD81 MFI was significantly higher in HCV-infected compared to HBV-infected patients and healthy controls. Both increased CD81 MFI and CD5+ B-cell expansion were associated with the production of rheumatoid factor and mixed cryoglobulins and positively correlated with HCV viral load and histological activity index. The overexpression of CD81 and the expansion of CD5+ peripheral B-cells in HCV-infected patients may possibly play a role in the development of HCV-associated autoimmunity and lymphoproliferation.

Severity and correlates of liver disease in hepatitis C virus-infected injection drug users

Between May 1996 and June 1998, 210 members of a cohort of 1,667 hepatitis C virus (HCV)-infected injection drug users (IDUs) were selected for liver biopsy procedure after stratification based on 2 consecutive serum alanine transaminase (ALT) levels. Liver histology, which could be fully evaluated for 207 subjects, was classified by using the modified Ishak scores. At the time of biopsy, the median age of subjects was 41.3 years and the median estimated duration of HCV infection was 20.7 years; 94% were African American; 78% men; 31% were human immunodeficiency virus (HIV) seropositive; and 76% had HCV genotype 1a or 1b. Total modified histologic activity index (MHAI) scores ranged from 0 to 9, and 26.6% had a total MHAI score of 5 or greater. Persons with a total MHAI score of 5 or greater were more likely to be HIV infected (P =.04). Higher fibrosis, indicated by Ishak modified fibrosis scores of 3 to 6, was present in 10.1% of subjects and was found more often in those older than 46 years of age (the highest quartile) (P <.01). Both fibrosis scores of 3 or greater and total scores of 5 or greater were associated with elevated ALT, aspartate transaminase (AST), and gamma-glutamyl transpeptidase (GGT) levels (P <.01). When serial values were considered, the results of liver enzyme testing could reduce the probability of an IDU having a fibrosis score of 3 or greater from 10% to 3%. In conclusion, these data indicate that severe liver disease is uncommon in this urban, HCV-infected IDU cohort, especially in younger persons and those with repeatedly normal liver enzymes.

Real-time RT-PCR for quantitation of hepatitis C virus RNA

A newly developed real-time RT-polymerase chain reaction assay for quantitation of hepatitis C virus (HCV) RNA in human plasma and serum was applied. A pair of primers and a probe (molecular beacon) were designed that are specific for the recognition of a highly conservative 5'-non-coding region (5'-NCR) in HCV genome. HCV real-time RT-PCR assay had a sensitivity of 1000 RNA copies per reaction, with a dynamic range of detection between 10(3) and 10(7) RNA copies. The coefficient variation of threshold cycle (Ct) values in intra- and inter-runs were less than 1.37 and 4.66%, respectively. The real-time RT-PCR assay on the HCV sero-positive samples yielded reproducible data, with less than 2.09% of the inter-assay variation. In order to determine its potential for clinical diagnosis, real-time RT-PCR was used to examine the HCV RNA levels in plasma from sero-positive and negative subjects, showing that the assay is highly sensitive and has specificity of 100%. It was demonstrated that the real-time RT-PCR was able to amplify HCV RNA in reference sera with seven genotypes (1A, 1B, 2B, 3A, 4, 5A and 6A) that include six major HCV genotypes circulated in the world. Since HCV is a major pathogen of post-transfusion and community-transmitted non-A, non-B hepatitis, this assay has a broad application for basic and clinical investigations.

Fluctuation of serum HCV-RNA levels in untreated blood donors with chronic hepatitis C virus infection

The hepatitis C virus (HCV)-RNA levels were measured in 281 serum samples from 32 untreated volunteer blood donors prospectively collected over a period of 14-73 months. The HCV-RNA levels were tested by the branched DNA signal amplification assay. The mean HCV-RNA levels of each donor ranged from 4.92 log10-6.36 log10 gene equivalents/mL (25%, median, 75% percentile; 5.51, 5.79, 6.12 log10 gene equivalents/mL). The fluctuations of HCV-RNA levels in individuals, represented by the ratio of the maximum value divided by the minimum value, ranged from a 1.7- to a 141-fold change. Fluctuations with more than a 10-fold change were observed in five subjects: 11-, 15-, 17-, 96- and 141-fold changes. Eleven subjects were followed for at least 5 years; all subjects had fluctuations of HCV-RNA levels greater than 3-fold during the observation period. No blood donor was observed whose HCV levels changed from a high-level phase to a low-level phase or from low to high. No subjects cleared HCV during follow-up, although two had undetectable HCV-RNA levels transiently. These findings reveal that changes in HCV-RNA levels occur which are unrelated to treatment with interferon and ribavirin.

Advances in the molecular diagnosis of hepatitis C and their clinical implications

Serologic assays for diagnosis of hepatitis C infection may yield indeterminate results despite improvements in sensitivity and specificity through second- and third-generation assays. Direct detection of hepatitis C virus (HCV) RNA based on qualitative reverse transcription-polymerase chain reaction or transcription-mediated amplification allows diagnosis in the early stages of acute infection and in patients unable to mount an antibody response. Quantitative HCV RNA assays are useful for selecting appropriate antiviral therapies, but until recently they have lacked comparability between tests. More sensitive qualitative assays should be used for determining duration of treatment or recognizing a sustained virologic response to therapy. Hepatitis C virus genotyping can be performed from a limited sequence analysis of the viral genome by using various techniques. Although newer genotyping methods are relatively practicable and are satisfactory for the discrimination of the majority of genotypes, discrimination between subtypes can be challenging. Serologic typing of HCV lacks sensitivity and specificity compared with molecular-based techniques. Recent advances in serologic assays and nucleic acid detection techniques allow physicians to make accurate diagnoses, and these assays serve as important tools in treatment planning.

Immunopathogenesis of hepatitis C virus infection

Hepatitis C virus, a recently identified member of the family Flaviviridae, is an important cause of chronic viral hepatitis and cirrhosis. There are similarities in the nature of the immune response to this pathogen with immunity in other flavivirus and hepatotropic virus infections, such as hepatitis B. However, the high rate of viral persistence after primary hepatitis C infection, and the observation that neutralizing antibodies are not protective, would suggest that there are a number of important differences between hepatitis C, other flaviviruses, and hepatitis B. The phenomenon of quasispecies evolution and other viral factors have been proposed to contribute to immune evasion by hepatitis C virus. In the face of established persistent infection, virus-specific cytotoxic T lymphocytes may exert some control over viral replication. However, these same effectors may also be responsible for the progressive liver damage characteristic of chronic hepatitis C infection. The nature of protective immunity, including the role of innate immune responses early after hepatitis C exposure, remains to be defined.

The natural history of hepatitis C virus infection

The natural history of HCV infection remains ill-defined. The knowledge accumulated on the progression of HCV to date is important, however. It is now abundantly clear that the progression of disease is generally slow, and the development of cirrhosis and its complications is a possibility, not a probability as hitherto thought. Predicting the outcome remains a quandary for clinicians. Ultimately it will be possible to define the natural history of hepatitis C infection through a combination of research in the fields of virology, immunology, and molecular biology and by monitoring the biochemical and histologic progress of the disease. Only then will it be possible to intervene appropriately and develop new therapies to prevent the progression to cirrhosis and hepatocellular carcinoma.

Effect of HCV viral dynamics on treatment design: lessons learned from HIV

Viral load measurements provide an indication of viral replication, and thereby serve as a valuable tool to guide the initiation of therapy and subsequent changes. Plasma human immunodeficiency viral load strongly predicts the rate of decrease in CD4+ lymphocyte count, and progression to AIDS and death. Furthermore, the efficacy of antiretroviral therapy can be assessed by monitoring changes in plasma human immunodeficiency viral load. Similarly, viral load provides valuable information about the natural history of the hepatitis C virus infection. Hepatitis C viral load can be used to predict the likelihood of response to standard interferon-alpha treatment and other interferon-alpha regimens and to monitor treatment efficacy. Increased understanding of the natural history of the hepatitis C virus infection and the nature of resistance to interferon-alpha therapy suggests that effective treatment regimens must maintain serum levels of interferon-alpha. Ideally, interferon-alpha serum levels should provide constant pressure on the virus and should prevent viral rebound, thereby avoiding continued viral replication and minimizing the potential for emergence of resistant quasi-species. Current regimens designed to address these points include early aggressive intervention, combination drug regimens, prolonged maintenance, and novel interferons. By enabling the design and rapid assessment of new treatment regimens, viral load measurement will revolutionize the clinical management of the hepatitis C virus infection, as it has the HIV.

Quantitation of hepatic hepatitis C virus RNA in patients with chronic hepatitis C. Relationship with severity of disease, viral genotype and response to treatment

BACKGROUND/AIMS

To determine the correlation between hepatic hepatitis C virus (HCV) RNA and histological lesions, viral genotype or response to alpha interferon therapy.

METHODS

Forty-three patients with chronic hepatitis C (14 sustained responders (SR) and 29 non-sustained responders (NSR)) were studied. A liver tissue sample was obtained before and 1 year after treatment. Quantitation of hepatic HCV-RNA was performed by competitive PCR.

RESULTS

Before treatment, HCV-RNA was detectable in all liver samples. There was no association between hepatic HCV-RNA and the severity of liver lesions. There was a significant association between old age and hepatic HCV-RNA (P = 0.03). There was an association, at the limit of significance, between genotype 1 and high hepatic HCV-RNA amounts (15 x 106 and 4.1 x 10(6) copies/g, P = 0.05). Pre-treatment hepatic HCV-RNA amounts were lower in SRs than in others (0.65 x 10(6) and 13.2 x 10(6) copies/g, P = 0.0002). After treatment, no liver HCV-RNA was detectable in the SRs while in the NSRs, the HCV-RNA amounts were unchanged.

CONCLUSIONS

The amount of hepatic HCV-RNA is correlated to genotype and response to interferon therapy but not to histologic lesions. Hepatic HCV-RNA clearance is observed in SRs, suggesting viral eradication.

Hepatitis C infection in liver transplantation

Hepatitis C-associated liver failure is the most common indication for liver transplantation and recurs nearly universally following transplantation. Histological evidence of recurrence is apparent in approximately 50% of HCV-infected recipients in the first postoperative year. Approximately 10% of HCV-infected recipients will die or lose their allograft secondary to hepatitis C-associated allograft failure in the medium term. While the choice of calcineurin inhibitor and/or the use of azathioprine have not been clearly shown to affect histological recurrence of hepatitis C or the frequency of rejection in hepatitis C-infected recipients, cumulative exposure to corticosteroids is associated with increased mortality, higher levels of HCV viremia and more severe histological recurrence. In contrast to nonhepatitis C-infected recipients, treatment for acute cellular rejection is associated with attenuated patient survival among recipients with hepatitis C. The development of steroid-resistant rejection is associated with a greater than five-fold increased risk of mortality in HCV-infected liver transplant recipients. In lieu of large studies in a post-transplant population therapy with pegylated interferon (+/- ribavirin) should be considered in recipients with histologically apparent recurrence of hepatitis C before total bilirubin exceeds 3 mg/dL. The role of hepatitis C immunoglobulin and new immunosuppression agents in the management of post-transplant hepatitis C infection is still evolving. Overall, HCV-infected recipients who undergo retransplantation experience 5-year patient and graft survival rates that are similar to recipients undergoing retransplantation who are not HCV-infected.

Advances in the molecular diagnosis of hepatitis C and their clinical implications

Serologic assays for diagnosis of hepatitis C infection may yield indeterminate results despite improvements in sensitivity and specificity through second- and third-generation assays. Direct detection of hepatitis C virus (HCV) RNA based on qualitative reverse transcription-polymerase chain reaction or transcription-mediated amplification allows diagnosis in the early stages of acute infection and in patients unable to mount an antibody response. Quantitative HCV RNA assays are useful for selecting appropriate antiviral therapies, but until recently they have lacked comparability between tests. More sensitive qualitative assays should be used for determining duration of treatment or recognizing a sustained virologic response to therapy. Hepatitis C virus genotyping can be performed from a limited sequence analysis of the viral genome by using various techniques. Although newer genotyping methods are relatively practicable and are satisfactory for the discrimination of the majority of genotypes, discrimination between subtypes can be challenging. Serologic typing of HCV lacks sensitivity and specificity compared with molecular-based techniques. Recent advances in serologic assays and nucleic acid detection techniques allow physicians to make accurate diagnoses, and these assays serve as important tools in treatment planning.