Sustained virological response is associated with clearance of hepatitis C virus RNA and a decrease in hepatitis C virus antibody

Change in hepatitis C virus positivity among needle-stick injury source patients: a 10-year experience in a Japanese tertiary hospital

Background

As a blood-borne pathogen, hepatitis C virus (HCV) has long been a major threat associated with needle-stick injuries (NSIs) mainly because no vaccine is available for HCV. Following an NSI, we usually test the source patient for HCV antibody (HCV-Ab). Since HCV-Ab positivity does not necessarily indicate current infection, HCV RNA is further examined in patients positive for HCV-Ab. Direct-acting antivirals (DAAs) have enabled us to treat most HCV-infected patients; therefore, we speculate that the rate of HCV RNA positivity among HCV-Ab-positive patients decreased after the emergence of DAAs. This cross-sectional study was performed to investigate the change in the actual HCV RNA positivity rate in source patients before and after the interferon (IFN)-free DAA era.

Methods

This was a cross-sectional study of NSI source patients at a tertiary academic hospital in Japan from 2009 to 2019. IFN-free DAA regimens were first introduced in Japan in 2014. Accordingly, we compared HCV status of NSI source patients that occurred between 2009 and 2014 (the era before IFN-free DAAs) with those that occurred between 2015 and 2019 (the era of IFN-free DAAs) in a tertiary care hospital in Japan.

Results

In total, 1435 NSIs occurred, and 150 HCV-Ab-positive patients were analyzed. The proportion of HCV RNA-positive patients significantly changed from 2009 through 2019 (p = 0.005, Cochran–Armitage test). Between 2009 and 2014, 102 source patients were HCV-Ab-positive, 78 of whom were also positive for HCV RNA (76.5%; 95%CI, 67.4–83.6%). Between 2015 and 2019, 48 patients were HCV-Ab-positive, 23 of whom were also positive for HCV RNA (47.9%; 95%CI, 34.5–61.7%; p = 0.0007 compared with 2009–2014). In the era of IFN-free DAAs, 9 of 23 HCV RNA-negative patients (39.1%) and 2 of 22 HCV RNA-positive patients (9.1%) were treated with an IFN-free combination of DAAs (p = 0.0351). Regarding the departments where NSIs occurred, HCV RNA-negative patients were predominant in departments not related to liver diseases in the era of IFN-free DAAs (p = 0.0078, compared with 2009–2014).

Conclusions

Actual HCV RNA positivity in source patients of NSIs decreased after the emergence of IFN-free DAAs. IFN-free DAAs might have contributed to this reduction, and HCV RNA-negative patients were predominant in departments not related to liver diseases in the era of IFN-free DAAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06117-4.

Liver Pathologic Changes After Direct-Acting Antiviral Agent Therapy and Sustained Virologic Response in the Setting of Chronic Hepatitis C Virus Infection

CONTEXT.—

Treatment of chronic viral hepatitis C (HCV) infection with direct-acting antiviral agents (DAAs) results in cure, or sustained viral response (SVR), in more than 90% of patients. However, there are subsets of patients who have persistent liver inflammation and fibrosis and develop hepatocellular carcinoma (HCC) despite achieving SVR. A possible reason for these phenomena may be the presence of virus particles in liver tissue but not blood, otherwise defined as occult infection.

OBJECTIVE.—

To describe liver histologic findings following successful DAA therapy, test HCV RNA by (liver) tissue polymerase chain reaction in treated cases, and identify predictive markers for HCC development in treated cases.

DESIGN.—

A total of 96 identified patients were divided into 4 groups, each differentiated by the presence or absence of SVR and HCC. Groups were compared for several clinicopathologic variables, including degree of inflammation and fibrosis, and the 'directionality' of fibrosis in cirrhotic livers using the novel progressive-indeterminate-regressive scoring system.

RESULTS.—

Overall, we found a significant decrease in inflammation in SVR patients. None of the patients showed regression of their cirrhosis following treatment. No evidence of occult HCV infection was seen in 40 livers tested, including 21 with HCC. The number of patients who developed HCC was similar in the SVR and non-SVR groups, and increased inflammation and fibrosis were associated with HCC development.

CONCLUSIONS.—

Following DAA-SVR there appears to be an overall decrease in inflammation, but the fibrosis tends to persist, at least in the short term (median follow-up of 20.2 months).

Restoration of HCV-Specific Immune Responses with Antiviral Therapy: A Case for DAA Treatment in Acute HCV Infection

Worldwide, 71 million individuals are chronically infected with Hepatitis C Virus (HCV). Chronic HCV infection can lead to potentially fatal outcomes including liver cirrhosis and hepatocellular carcinoma. HCV-specific immune responses play a major role in viral control and may explain why approximately 20% of infections are spontaneously cleared before the establishment of chronicity. Chronic infection, associated with prolonged antigen exposure, leads to immune exhaustion of HCV-specific T cells. These exhausted T cells are unable to control the viral infection. Before the introduction of direct acting antivirals (DAAs), interferon (IFN)-based therapies demonstrated successful clearance of viral infection in approximately 50% of treated patients. New effective and well-tolerated DAAs lead to a sustained virological response (SVR) in more than 95% of patients regardless of viral genotype. Researchers have investigated whether treatment, and the subsequent elimination of HCV antigen, can reverse this HCV-induced exhausted phenotype. Here we review literature exploring the restoration of HCV-specific immune responses following antiviral therapy, both IFN and DAA-based regimens. IFN treatment during acute HCV infection results in greater immune restoration than IFN treatment of chronically infected patients. Immune restoration data following DAA treatment in chronically HCV infected patients shows varied results but suggests that DAA treatment may lead to partial restoration that could be improved with earlier administration. Future research should investigate immune restoration following DAA therapies administered during acute HCV infection.

Study of the Humoral Immune Response towards HCV Genotype 4 Using a Bead-Based Multiplex Serological Assay

Hepatitis C is one of the leading causes of hepatocellular carcinoma and remains at a high prevalence in Egypt and other resource-limited countries. Several hepatitis C virus (HCV) genotypes are distributed throughout the world, with genotype 4 being most common in North and Central Africa. We developed a multiplex serological assay for the detection of the HCV specific humoral immune response, with a focus on genotype 4. For the multiplex HCV assay we used twelve antigenic regions of different HCV proteins (core, and non-structural (NS) proteins NS3, NS4, NS5A, NS5B) and validated the assay technically and clinically. In comparison to a commercially available test, our assay revealed a higher sensitivity for genotype 4, and is therefore more suited for studying immune seroconversion in samples from acutely infected Egyptian HCV patients. Furthermore, our assay discriminates acutely and chronically infected HCV patients. Of 296 well characterized HCV patient samples, 83.9% of the acute samples and 86.5% of the chronic samples could be correctly classified. In sum, this newly developed serological HCV assay has a higher sensitivity for HCV genotype 4, and can thus improve diagnostic accuracy. Through the discrimination of acutely and chronically infected HCV patients the assay may be useful in supporting clinical management of HCV patients.

The dynamics of HCV-specific antibody responses in HIV/HCV patients on long-term antiretroviral therapy

Antibody responses have not been fully characterised in chronically HIV/HCV patients receiving antiretroviral therapy (ART). Seventeen HIV/HCV patients receiving ART were followed for a median (range) interval of 597 (186-766) weeks. Prior to ART, HIV/HCV patients had lower levels of antibodies reactive with HCV core and JFH-1, and lower genotype cross-reactive neutralising antibodies (nAb) titres, than HCV patients. Levels of JFH-1 reactive antibody increased on ART, irrespective of CD4⁺ T-cell counts or changes in serum ALT levels. The appearance of nAb coincided with control of HCV viral replication in five HIV/HCV patients. In other patients, HCV viral loads remained elevated despite nAb responses. Sustained virological responses following HCV therapy were associated with reduced antibody responses to JFH-1 and core but elevated responses to non-structural proteins. We conclude that nAb responses alone may fail to clear HCV, but contribute to control of viral replication in some HIV/HCV patients responding to ART.

Favorable Outcomes of Chinese HCV-Related Cirrhotic Patients with Sustained Virological Response after Pegylated Interferon Plus Ribavirin Treatment

Few studies have conducted follow-up investigations of the clinical course in HCV-related cirrhotic patients who achieved a sustained virological response (SVR) with pegylated interferon plus ribavirin treatment (PegIFN + RBV). We investigated the clinical course and laboratory data in a prospective cohort study enrolling HCV-related cirrhotic patients who received PegIFN + RBV between August 2008 and July 2013 in China. Complete blood counts, liver function tests, and HCV-RNA were serially examined. Liver-related complications were recorded. To detect hepatocellular carcinoma (HCC), alpha-fetoprotein assays, and ultrasound scans were repeated at 6-month intervals. Twenty-five patients were enrolled, including 8 patients with decompensation events before treatment. Eighteen patients achieved SVR with a mean follow-up period of 25.78 months. During the follow-up period, only one patient exhibited HCV-RNA positivity and no decompensation events were detected, but 4 patients developed HCC after SVR. APRI decreased more in patients with SVR than in patients with non-SVR (median, -1.33 versus 0.86, P < 0.001). The albumin levels and platelet counts significantly increased during the follow-up period after SVR (44.27 ± 4.09 versus 42.63 ± 4.37, P = 0.037 and 173.89 ± 87.36 versus 160.11 ± 77.97, P = 0.047). These data indicated that HCV-related cirrhotic patients with SVR after PegIFN + RBV may have a favorable clinical course and improvements in laboratory data. Moreover, HCC should be monitored.

Ten-year follow-up analysis of chronic hepatitis C patients after getting sustained virological response to pegylated interferon-α and ribavirin therapy

There is little data on the long-term follow-up outcomes of chronic hepatitis C patients achieving sustained virological response (SVR) after treatment with peglylated interferon-α plus ribavirin. We prospectively investigated the overall clinical, biochemical, virological and histological outcomes in a ten-year cohort study of 325 patients with chronic hepatitis C achieving SVR to pegylated interferon-α and ribavirin therapy. Patients underwent consistent clinical, biochemical and virological evaluation every six months, and patients with pretherapy Ishak fibrosis score ≥2 were invited to accept a second liver biopsy at the last follow-up. Liver biopsy specimens were evaluated using Ishak's scoring system. At the end of follow-up, five patients developed decompensated liver cirrhosis. One patient (0.3%) with pretherapy cirrhosis was diagnosed with hepatocellular carcinoma (HCC). A total of 305 patients (94%) had normal serum ALT and AST levels during the entire period of follow-up. Twenty-seven patients (8%) had conclusive evidence of virological relapse. Among the 117 patients with paired pretherapy and long-term follow-up biopsies, 96 (82%) had a decreased fibrosis score. Ninety-nine (79%) had a decrease in combined inflammation score. Thirty-seven (32%) had normal or nearly normal livers on long-term follow-up biopsy. SVR achieved with PEG-IFN-α and RBV combination therapy is durable, while late virological relapse may still occur in some patients. Clinical outcomes for patients who obtain SVR are excellent, although the patients with cirrhosis are still at a low risk of hepatocellular carcinoma.

Faldaprevir for the treatment of genotype-1 hepatitis C virus

Historically, pegylated interferon in combination with ribavirin was the standard of care in hepatitis C virus; however, this combination is often poorly tolerated, has a significant side-effect profile and is of limited efficacy in hepatitis C virus genotype-1. More recently, pegylated interferon/ribavirin has been combined with direct acting antiviral agents such as the first generation NS3/4A protease inhibitors. Faldaprevir, a first generation, second-wave protease inhibitor, when used with a pegylated interferon/ribavirin regimen, has also been shown to increase treatmentsuccess while shortening treatment duration; however, second generation direct acting antiviral agents offer even betterefficacy and tolerability. Various direct acting antiviral agent combinations in interferon-free regimens have been effective in over 95% of patients and are now in licensed use. While faldaprevir was a pioneering drug, by the time it reached late phase development it was superseded by newer agents.

Hepatitis C virus resistance to interferon therapy: an alarming situation

Hepatitis C virus is presently a major public health problem across the globe. The main objective in treating hepatitis C virus (HCV) infection is to achieve a sustained virological response (SVR). Interferon-α (IFN-α) and pegylated interferon (PegIFN) in combination with Ribavirin (RBV) are the choice of treatment nowadays against chronic hepatitis C. There are several mechanisms evolved by the hepatitis C virus that facilitate the persistence of virus and further lead the patient’s status as non responder. Various factors involved in patient’s lack ofresponse to the therapy include: (1) viral factors, (2) host factors, (3) molecular mechanisms related to the lack of response and (4) social factors. Herein we have made an attempt to summarize all the related predictors of drug resistance in one article so that the future polices can be planned to overcome this obstacle and potential therapies can be designed by considering these factors.

Patients co-infected with hepatitis C virus (HCV) and human immunodeficiency virus recover genotype cross-reactive neutralising antibodies to HCV during antiretroviral therapy

When severely immunodeficient HIV/HCV co-infected patients are treated with antiretroviral therapy, it is important to know whether HCV-specific antibody responses recover and whether antibody profiles predict the occurrence of HCV-associated immune restoration disease (IRD). In 50 HIV/HCV co-infected patients, we found that antibody reactivity and titres of neutralising antibodies (nAb) to JFH-1 (HCV genotype 2a virus) increased over 48 weeks of therapy. Development of HCV IRD was associated with elevated reactivity to JFH-1 before and during the first 12 weeks of therapy. Individual analyses of HCV IRD and non-HCV IRD patients revealed a lack of an association between nAb responses and HCV viral loads. These results showed that increased HCV-specific antibody levels during therapy were associated with CD4(+) T-cell recovery. Whilst genotype cross-reactive antibody responses may identify co-infected patients at risk of developing HCV IRD, neutralising antibodies to JFH-1 were not involved in suppression of HCV replication during therapy.

Recent advances and future directions in the management of hepatitis C infections

Current estimates indicate that the hepatitis C virus is the leading cause of death in the United States with infection rates steadily increasing. Successful treatment is made difficult by the presence of various host, virus, and treatment-related factors, warranting the development of new approaches to combat the silent epidemic. The addition of telaprevir and boceprevir to the pharmacotherapeutic arsenal drastically improved success rates in genotype 1 infected patients, but rapid development of resistance mechanisms, increases in adverse effects, and a low spectrum activity proved to be barriers to efficacious treatment. In late 2013, two new agents were approved - sofosbuvir and simeprevir - that have higher barriers to resistance, favorable safety profiles, and profoundly improved success rates; however higher costs associated with the new medications could limit their wider utilization. Further strategies to combat the virus are under development, ranging from interferon-free regimens as well as prophylactic and therapeutic vaccines to applications of nanotechnology, helping us get closer to improved treatment of patients infected with hepatitis C.

Prevalence of occult hepatitis C infection in chronic hemodialysis and kidney transplant patients

BACKGROUND & AIMS

Detection of hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMC) and/or hepatocytes in absence of HCV RNA in serum, designated as 'occult HCV infection', has been a matter of controversy in recent years. We investigated for the first time the prevalence of occult HCV infection in large cohorts of chronic hemodialysis (CHD) and kidney transplant (KTx) patients.

METHODS

We enrolled 417 CHD patients, 417 KTx recipients and 2 control groups - 25 anti-HCV (antibody against HCV)-positive and HCV RNA-positive patients with chronic hepatitis C, and 40 anti-HCV-, HCV RNA-, and HBsAg-negative healthy subjects. HCV RNA was tested in serum and PBMC using a sensitive commercial assay.

RESULTS

In CHD patients, the prevalence of anti-HCV was 3.6% (15/417) and of positive serum HCV RNA 2.4% (10/417). HCV RNA was detected in PBMC in 1/407 (0.25%) HCV serum RNA-negative patients ("occult HCV infection"). In KTx recipients, prevalence of anti-HCV was 4.8% (20/417) and of positive serum HCV RNA 4.6% (19/417). Occult HCV infection was found in 2/398 (0.5%) serum HCV RNA-negative patients. On a mean longitudinal follow-up of 30months of the 3 patients with occult HCV infection, there was no clinical or virological evidence of HCV infection.

CONCLUSIONS

The prevalence of occult HCV infection was very low in our CHD and KTx patients, and it did not appear to be clinically relevant. Further studies in geographic populations with high HCV endemicity are required to clarify the significance of occult HCV infection in these patient groups.

Loss of anti-hepatitis C virus antibodies following therapeutic sustained virological response in a HIV co-infected patient

No data are available for the kinetics of anti-Hepatitis C Virus (HCV) antibodies in HIV/HCV co-infected patients after sustained virological response (SVR). We present a case of a HIV/HCV co-infected patient, showing a significant anti-HCV antibodies decrease during therapy, who achieved a HCV seroreversion 3 years after SVR. Among them, antibodies to core protein, the most strongly antigenic protein showed significant decrease. Our results indicate an absence of antigenic stimulation suggesting a total clearance of HCV.

Hepatitis C virus (HCV)-specific memory B-cell responses in transiently and chronically infected HIV positive individuals

BACKGROUND

Antibody responses to hepatitis C virus (HCV) occur delayed and overly decline after viral clearance indicating that the B-cell response to HCV is abnormal. Virus-specific memory B-cells have recently been found in infected individuals, but the viral exposure requirements for the generation of these cells is unknown.

OBJECTIVES

The primary goal of this study was to quantify and compare the HCV-specific memory B-cell response between chronic and resolved HCV-infected individuals. A secondary goal was to examine if HIV-specific memory B-cell responses are maintained during HCV co-infection.

STUDY DESIGN

HCV core protein- and HIV-specific memory B-cell responses were examined in HIV/HCV-infected individuals treated 4-30 weeks after HCV diagnosis. Memory B-cell frequencies were compared between chronically and transiently infected individuals.

RESULTS

Chronically infected individuals had vigorous HCV-specific memory B-cell responses and antibodies, whereas subjects with transient viremia showed low or undetectable virus-specific B-cell responses. In addition, chronically HIV/HCV-infected subjects had robust HIV-specific memory B-cell responses.

CONCLUSIONS

Whereas chronic HCV infection induces virus-specific antibodies and memory B-cells, transient infection in individuals with sustained viral response to therapy does not stimulate a durable HCV-specific B-cell response indicating that the formation of long-lived virus-specific B-cells is suppressed in the early phase of infection. This may contribute to the inability to spontaneously clear HCV infection.

Durability of sustained virologic response in chronic hepatitis C

BACKGROUND/AIMS

The aim of this study is to investigate the rate of sustained virologic response (SVR) in chronic hepatitis C patients receiving antiviral treatment.

METHODS

The files of patients with chronic hepatitis C treated with interferon±ribavirin between 1995 and 2009 were reviewed retrospectively. Six months after the end of treatment, patients with negative hepatitis C virus (HCV)-RNA (<50 IU/mL, as determined by the polymerase chain reaction method) were enrolled in the study.

RESULTS

The mean age of 196 patients (89 males) was 46.13±11.10 years (range, 17 to 73 years). In biopsies, the mean stage was 1.50±0.94; histological activity index was 7.18±2.43. In total, 139 patients received pegylated interferon (IFN)+ribavirin, 21 patients received classical IFN+ribavirin, and 36 patients received IFN alone. The HCV genotypes of 138 patients were checked: 77.5% were genotype 1b, and 22.5% were other genotypes. After achievement of SVR, the median follow-up period was 33.5 months (range, 6 to 112 months), and in this period relapse was only detected in two patients (1.02%) at 18 and 48 months after treatment.

CONCLUSIONS

In total, 98.9% of patients with SVR in chronic hepatitis C demonstrated truly durable responses over the long-term follow-up period of 3 years; relapsed patients had intermittent or low-grade viremia.

Earlier sustained virologic response end points for regulatory approval and dose selection of hepatitis C therapies

BACKGROUND & AIMS

Trials of therapies for chronic hepatitis C have used detection of hepatitis C virus (HCV) at week 24 of follow-up (sustained virologic response [SVR] 24) as a primary end point. However, there is increasing evidence that most patients who have an SVR at earlier time points (such as SVR12) maintain it until week 24. Use of earlier time points for key regulatory decisions (SVR12) and dose selection (SVR4) could facilitate HCV drug development.

METHODS

We assessed data from 15 phase II and III trials, 3 pediatric studies, and 5 drug-development programs to determine the concordance between SVR24 and SVR12 or SVR4. Data were analyzed from groups of subjects who received various combinations and regimens with interferon, pegylated-interferon, ribavirin, and direct-acting antivirals.

RESULTS

The positive predictive value (PPV) of SVR12 was 98% and the negative predictive value (NPV) was 99% for SVR24 among subjects with genotype 1 HCV infection. A similar level of concordance was observed for subjects with HCV genotype 2 or 3 infections, as well as in pediatric studies. About 2% of subjects who achieved an SVR12 subsequently relapsed by week 24 (did not achieve an SVR24). Furthermore, the treatment effect size (difference between treatment and active control arms) was similar for subjects with SVR12 and SVR24. The PPV of SVR4 was 91% and the NPV was 98% for SVR24 in subjects with genotype 1 HCV infection.

CONCLUSIONS

SVR12 and SVR24 measurements were concordant in a large population of subjects with HCV infection who participated in clinical trials with various treatment regimens and durations. SVR12 is suitable as a primary end point for regulatory approval. SVR4 might be used to guide dose and treatment strategies in trials.

Decreased anti-hepatitis C virus titer and associated factors in chronic hepatitis C patients after sustained virological response: a prospective study

BACKGROUND AND AIM

Long-term trends of anti-hepatitis C virus (HCV) antibody titer and their associated factors in patients with sustained virological response (SVR) were investigated.

METHODS

From May 1999 to July 2005, a total of 166 SVR consecutive patients (M/F: 86/80) were enrolled. Anti-HCV titer, samples to cut-off (S/CO) ratios, were measured with AxSYM HCV version 3.0. Their S/CO ratios were followed every 6 months after SVR and the patterns over time were identified by trajectory analyses. Changes of recombinant immunoblot assay (RIBA) pattern before treatment and end of follow-up were compared (n = 64).

RESULTS

The mean duration of follow-up was 4.7 ± 1.5 years (median 4.3; range 3-9 years). The rates of S/CO ratios decreased annually (P < 0.001). Two of them (1.2%) achieved seroreversion. Trajectory groups included lower pretreatment S/CO ratios (LAB, n = 83), rapid decrease (RD, n = 62) and slow decrease (SD, n = 21) groups. Comparing LAB to RD group, odds ratio (OR) of increased platelet count per 1 unit and interferon regimen was 1.12 (95% confidence interval [CI] 1.04-1.20) and 2.17 (95% CI 1.04-4.52) respectively. Comparing SD to LAB and RD groups, the OR of advanced fibrotic stage, using mild fibrotic stage as a reference, was 4.33 (95% CI 1.49-12.63). Reaction strength of all four RIBA bands decreased significantly at the end of follow-up.

CONCLUSIONS

Anti-HCV titers decreased annually during long-term follow-up after SVR. Higher pretreatment platelet count, interferon regimen and mild fibrosis were associated with decreased anti-HCV titers. However, only a few cases achieved seroreversion. All RIBA bands decreased significantly after long-term follow-up.

Longitudinal changes of the laboratory data of chronic hepatitis C patients with sustained virological response on long-term follow-up

There is no study that follows up longitudinal changes in laboratory data of patients with C-viral chronic liver disease (C-CLD) who achieved sustained virological esponse (SVR) with interferon treatment in a long-term study. We investigated the laboratory data in a long-term retrospective cohort study of 581 patients with C-CLD who underwent liver biopsy between January 1986 and December 2005. 467 were treated with interferon and 207 of these patients achieved SVR with follow-up periods of 8.36 ± 5.13 years. Alanine aminotransferase (ALT) levels, albumin levels, platelet counts, and the aspartate aminotransferase (AST)-to-platelet ratio index (APRI) values were serially examined during the follow-up period. None of the 207 patients with SVR exhibited hepatitis C virus (HCV) RNA positivity more than 6 months after the end of IFN treatment. Platelet counts and albumin levels increased only in those with eradication of HCV. APRI values decreased more in patients with SVR than in those with nonsustained virological responses (non-SVR). Patients who achieved SVR and had fibrosis stage 0-1 and 2-4 at enrolment had platelet counts that longitudinally increased by 2.81 ± 3.95 and 5.49 ± 4.53 × 10(3) /μL during the 10-year follow-up period, respectively. Albumin levels continuously increased during the first 2 years by 0.15 ± 0.31 and 0.33 ± 0.37 in fibrosis stage 0-1 and 2-4, respectively and then plateaued. ALT levels decreased rapidly one year after the start of treatment by 110.3 ± 140.0 and 100.5 ± 123.4 in fibrosis 0-1 and 2-4, respectively. HCV RNA negativity persisted in all patients with SVR, and laboratory data including APRI longitudinally improved during the long-term follow-up period.

Occult hepatitis C virus infection and its relevance in clinical practice

Hepatitis C virus (HCV) can persist in the liver, lymphoid (immune) cells, and serum of individuals long after an apparently complete therapy-induced or a spontaneous resolution of hepatitis C. This essential asymptomatic infection, called secondary occult HCV infection (OCI), usually occurs in anti-HCV antibody reactive individuals with normal liver function tests. This infection has been identified when the nucleic acid amplification assays of enhanced sensitivity were applied for the detection of HCV genome and its replication. In addition to the secondary OCI, a form of low-level HCV-RNA-positive infection of unknown etiology coinciding with moderately elevated serum liver enzymes and progressing in the absence of anti-HCV detectable by standard clinical assays has been reported. Because of its undefined origin, it can be termed cryptogenic OCI. In this review, the general characteristics of OCI, the ways of its detection and associated controversies, and the potential clinical implications of its existence will be concisely outlined.

Antiviral therapy: why does it fail in HCV-related chronic hepatitis?

HCV infection is a very common cause of chronic viral hepatitis. It is a worldwide health problem with approximately 170 million persons infected and areas of high endemicity in which the percentage of the population infected reaches 30%. It is a progressive disease that can lead to complications such as severe liver fibrosis and cirrhosis, ascites, esophageal varices, gastrointestinal bleeding and, in 30-50% of patients with cirrhosis, hepatocellular carcinoma. Extrahepatic pathologies such as mixed cryoglobulinemia, non-Hodgkin lymphoma and membrano-proliferative glomerulonephritis have been associated with HCV infection. Effective treatment exists, and is based on IFN-α. Sustained disappearance of the virus (sustained virological response) radically changes the natural history of chronic hepatitis C, with reduced or no disease progression and complications. Interferon-based treatment has improved over the years owing to the association with ribavirin and subsequently with 'pegylation' of interferon molecules. The present standard of care results in a response rate of up to 80% in some subpopulations. Nevertheless, some patients do not respond to this therapy. Several factors predicting nonresponse to interferon therapy have been investigated since it became available. These factors include the characteristics of the virus and of the subject infected, and the therapy used. The aim of this article is to provide an overview of these factors, and insights into the newly recognized causes of nonresponse to help clinicians select the most appropriate therapy for HCV viral hepatitis.

Sustained virologic response to antiviral therapy for chronic hepatitis C virus infection: a cure and so much more

Sustained virologic response (SVR) is defined as aviremia 24 weeks after completion of antiviral therapy for chronic hepatitis C virus (HCV) infection. In analyses of SVR durability, the incidence of late relapse is extremely low (<1%). Histologic regression of both necroinflammation and fibrosis has been demonstrated in paired liver biopsy samples in SVR-achieving patients. More noteworthy is the sustained responder's favorable prognosis even with baseline cirrhosis; despite mostly retrospective analyses, relative to nonresponders or to those untreated, patients with SVR have significantly fewer liver-related complications, less hepatocellular carcinoma, and fewer liver-related deaths. Although HCV is associated with insulin resistance, successful eradication of HCV appears to reduce the risk of impaired fasting glucose and diabetes development. In summary, chronic HCV infection is curable with SVR attainment, and with cure comes improved liver histology and more favorable clinical outcomes, in comparison with patients who do not achieve the same therapeutic milestone.

Mechanisms of non-response to antiviral treatment in chronic hepatitis C

Treatment of chronic hepatitis C virus (HCV) infection has substantially evolved over the past decade after the Consensus Conference organized by the European Association for the Study of the Liver in 1999. Since then, the standard of care (SOC) for patients with chronic hepatitis C has been the combination of pegylated interferon (pegIFN) alpha-2a or -2b and ribavirin. In patients infected with HCV genotype 1, by far the most frequent HCV genotype worldwide, such treatment leads to a cure of infection in only 40% to 50% of cases. Several factors have been identified to play a role in the outcome of therapy, including the treatment schedule, disease characteristics, viral, and host factors. Human genetic factors have been identified by a recent landmark discovery. However, these factors only partly explain the ability of IFN and ribavirin therapy to cure HCV infection. Several studies have demonstrated that, in non-responders, interferon-stimulated genes were up-regulated prior to therapy through unclear mechanisms. These findings, together with clinical, biochemical and histological data, may help better identify responders before starting therapy. This becomes particularly important as the standard treatment is physically and economically demanding. The future treatment of patients infected with HCV genotype 1 will be based on the combination of pegIFN and ribavirin with a protease inhibitor, telaprevir or boceprevir. Promising results of this triple combination in phase III clinical trials have been recently reported at the Liver Meeting 2010. With this therapy, higher cure rates will be achieved, but specific issues will be raised, such as the emergence of resistance to the protease inhibitors. The goal of this review is to discuss mechanisms involved in the non-response to current and future standard treatments.

Hepatitis C: viral and host factors associated with non-response to pegylated interferon plus ribavirin

Treatment for chronic hepatitis C virus (HCV) infection has evolved considerably in the last years. The standard of care (SOC) for HCV infection consists in the combination of pegylated interferon (PEG-IFN) plus ribavirin. However, it only induces a sustained virological response (SVR) in half of genotype 1-infected patients. Several viral and host factors have been associated with non-response: steatosis, obesity, insulin resistance, age, male sex, ethnicity and genotypes. Many studies have demonstrated that in non-responders, some interferon-stimulated genes were upregulated before treatment. Those findings associated to clinical, biochemical and histological data may help detect responders before starting any treatment. This is a very important issue because the standard treatment is physically and economically demanding. The future of HCV treatment would probably consist in the addition of specifically targeted antiviral therapy for HCV such as protease and/or polymerase inhibitors to the SOC. In genotype 1 patients, very promising results have been reported when the protease inhibitor telaprevir or boceprevir is added to the SOC. It increases the SVR rates from approximately 50% (PEG-IFN plus ribavirin) to 70% (for patients treated with a combination of PEG-IFN plus ribavirin plus telaprevir). Different elements are associated with non-response: (i) viral factors, (ii) host factors and (iii) molecular mechanisms induced by HCV proteins to inhibit the IFN signalling pathway. The goal of this review is to present the mechanisms of non-response, to overcome it and to identify factors that can help to predict the response to anti-HCV therapy.

Poor performance of hepatitis C antibody tests in hospital patients in Uganda

Most hepatitis C testing in Uganda is performed using commercial rapid strip assays (RSA) to detect antibodies to hepatitis C virus (anti-HCV), rather than enzyme immunoassays (EIA). The prevalence of hepatitis C antibodies in a Ugandan hospital population was determined using both methods to test their accuracy using nucleic acid testing (NAT) as a reference. Sera from 380 consecutive hospitalized Ugandan patients were tested for anti-HCV using an RSA in Uganda, with subsequent automated third-generation EIA testing in the United States, followed by NAT. Recombinant immunoblot assays (RIBA) were used as a supplementary test to detect anti-HCV epitopes. Overall, anti-HCV was detected in 48/380 (13%) by one or both antibody tests. Anti-HCV was detected in 19 (5.0%) patients by RSA and in 33 (8.7%) patients by EIA; only four patients were anti-HCV positive by both methods. Fourteen of the 48 anti-HCV positive patients had detectable serum HCV RNA, 7 each by bDNA assay or by PCR. RSA detected only 7 of 14 HCV RNA positive sera. Of 29 RNA negative but anti-HCV positive patients tested by RIBA, only two were anti-HCV positive; 27 were anti-HCV negative or indeterminate. Anti-HCV testing by RSA and/or EIA was neither sensitive nor specific for detection of ongoing HCV infection in hospitalized Ugandan patients. Our findings underscore the importance of confirmatory nucleic acid testing, which, despite its increased cost, appears essential to manage African patients with HCV.

High prevalence of late relapse and reinfection in prisoners treated for chronic hepatitis C

BACKGROUND AND AIM

Prisoners have a high prevalence of injection drug use (IDU) and chronic hepatitis C (CHC) infection. Treatment of CHC in these patients is effective; however, their long-term outcomes following treatment are unknown. We determined the durability of a sustained virological response (SVR) in prisoners treated for CHC.

METHODS

Patients were treated as part of routine clinical practice with interferon (IFN) and ribavirin. A retrospective review of medical records and a computerized pathology system was performed for clinical and laboratory information.

RESULTS

Seventy-four prisoners (70 males, mean age 34 years, IDU in 55%) were evaluable for a SVR over a 12-year period to December 2008; the mean follow-up period was 1243 days. Genotype 1, 2, 3, and 6 infection was present in 18, three, 38 and three patients, respectively; the genotype was unknown in 12. Three out of 52 biopsied had cirrhosis. Standard IFN was administered to 25 (34%; 11 with ribavirin), and 49 received pegylated IFN and ribavirin; one did not complete treatment, and two had breakthrough relapses. The end-of-treatment response was achieved in 57 and SVR in 53; 14 were non-responders. Five male patients, four with unknown genotypes and treated with standard IFN alone, relapsed late (following SVR, 9%). Five patients, all treated with pegylated IFN and ribavirin, were reinfected (one prior to and four following SVR).

CONCLUSIONS

Prisoners are often successfully treated for CHC. However, this retrospective study indicates that there is a high (17%) prevalence of late recurrence of viremia that is likely a reflection of reinfection due to ongoing risk-taking behavior.

Assessment of synthetic chimeric multiple antigenic peptides for diagnosis of GB virus C infection

The use of synthetic peptides of both structural and nonstructural proteins of GB virus C (GBV-C) has been studied for the development of new systems to diagnose infection caused by this virus. In an attempt to increase the antigenicity of linear peptide sequences, chimeric multiple antigenic peptides (MAPs) containing epitopes from E2, NS4, and NS5 GBV-C proteins have been synthesized. The synthetic constructs were evaluated by ELISA to establish whether the epitopes in chimeric branched peptides are more efficiently recognized by the specific antibodies compared to the monomeric linear sequences. Moreover, we have investigated the application of a commercial biosensor instrument for the detection of antibodies against the GBV-C in human serum samples. The results of the immunoassays reported in this work highlight the usefulness of synthetic tetrameric branched peptides containing sequences from envelope and nonstructural GBV-C proteins for the diagnosis of GBV-C infection. The potential clinical value of the MAP(4)(E2-NS5a) for the serodiagnosis of GBV-C infection was demonstrated, thus providing the basis for performing prevalence studies of the infection among the hemodialyzed and hepatitis C virus (HCV)-infected population.