Outcomes of Real-World Integrated HCV Microelimination for People Who Inject Drugs: An expansion of the Punjab Model

BACKGROUND

The prevalence of chronic hepatitis C (CHC) in People Who Inject Drugs (PWID) is 8-10% as compared to 3·6% in the general population in Punjab, India. We assessed the real-world efficacy and safety of free-of-charge generic direct-acting antivirals (DAAs), sofosbuvir with an NS5A inhibitor (ledipasvir, daclatasvir or velpatasvir)±ribavirin in the microelimination of CHC in PWID in a public health setting.

METHODS

An integrated care team at 25 sites provided algorithm based DAAs treatment to PWID supervised by telemedicine clinics between 18^th June 2016 and 31^st July 2019. The primary endpoint was sustained virological response at 12 weeks (SVR-12); the secondary endpoints were treatment completion, adherence, safety, and adverse events. ClinicalTrials.gov number: NCT01110447.

FINDINGS

We enrolled 3477 PWID (87·2% men; mean age 33·6±12·5 years; 83·8% rural; 6·8% compensated cirrhosis). While 2280 (65·5%) patients completed treatment, 1978 patients completed 12 weeks of follow up for SVR-12. SVR-12 was achieved in 91·1% of patients per protocol, 49.5% as per intention to treat (ITT) and 90·1% in a modified ITT analysis. Of 546 (15·7%) patients with treatment interruptions, 99 (19·7%) could be traced to test for SVR-12 with a cure rate of 77·8%. There were no major adverse events or consequent treatment discontinuation.

INTERPRETATION

Integrated care of PWID with CHC with DAAs is safe and effective. Measures for reducing treatment interruptions will further improve outcomes.

FUNDING

The Government of the state of Punjab, India under the Mukh Mantri Punjab Hepatitis C Relief Fund (MMPHCRF) project, funds the project.

Where are the children in national hepatitis C policies? A global review of national strategic plans and guidelines

BACKGROUND & AIMS

It is estimated that 3.26 million children and adolescents worldwide have chronic HCV infection. To date, the global response has focused on the adult population, but direct-acting antiviral (DAA) regimens are now approved for children aged ≥3 years. This global review describes the current status of policies on HCV testing and treatment in children, adolescents, and pregnant women in WHO Member States.

METHODS

We identified national strategic plans and/or clinical practice guidelines (CPGs) for HCV infection from a World Health Organization (WHO) database of national policies from Member States as of August 2019. A standardised proforma was used to abstract data on polices or recommendations on testing and treatment in children, adolescents and pregnant women. Analysis was stratified according to the country-income status and results were validated through WHO regional focal points through August 2020.

RESULTS

National HCV policies were available for 122 of the 194 WHO Member States. Of these, the majority (n = 71/122, 58%) contained no policy recommendations for either testing or treatment in children or adolescents. Of the 51 countries with policies, 24 had specific policies for both testing and treatment, and were mainly from the European region; 18 countries for HCV testing only (12 from high- or upper-middle income); and 9 countries for treatment only (7 high- or upper-middle income). Twenty-one countries provided specific treatment recommendations: 13 recommended DAA-based regimens for adolescents ≥12 years and 6 still recommended interferon/ribavirin-based regimens.

CONCLUSIONS

There are significant gaps in policies for HCV-infected children and adolescents. Updated guidance on testing and treatment with newly approved DAA regimens for younger age groups is needed, especially in most affected countries.

LAY SUMMARY

To date, the predominant focus of the global response towards elimination of hepatitis C has been on the testing and treatment of adults. Much less attention has been paid to testing and treatment among children and adolescents, although in 2018 an estimated 3.26 million were infected with HCV. Our review shows that many countries have no national guidance on HCV testing and treatment in children and adolescents. It highlights the urgent need for advocacy and updated policies and guidelines specific for children and adolescents.

Non-alcoholic fatty liver disease is a risk factor for occurrence of hepatocellular carcinoma after sustained virologic response in chronic hepatitis C patients: A prospective four-years follow-up study

Background and aim

The incidence of hepatocellular carcinoma (HCC) decreases significantly in chronic hepatitis C (CHC) patients with sustained virologic response (SVR) after pegylated-interferon plus ribavirin (PR) or direct-acting antiviral (DAAs) therapy. We follow-up a single cohort of CHC patients to identify risk factors associated with HCC development post-SVR.

Method

CHC patients with SVR in Beijing/Hong Kong were followed up at 12–24 weekly intervals with surveillance for HCC by ultrasonography and alpha-fetoprotein (AFP). Multivariate Cox proportional hazards regression analysis was used to explore factors associated with HCC occurrence.

Results

Between October 2015 and May 2017, SVR was observed in 519 and 817 CHC patients after DAAs and PR therapy respectively. After a median post -SVR follow-up of 48 months, HCC developed in 54 (4.4%) SVR subjects. By adjusted Cox analysis, older age (≥55 years) [HR 2.4, 95% CI (1.3–4.3)], non-alcoholic fatty liver diseases [HR 2.4, 95%CI (1.3–4.2), higher AFP level (≥20 ng/ml) [HR 3.4, 95%CI (2.0–5.8)], higher liver stiffness measurement (≥14.6 kPa) [HR 4.2, 95%CI (2.3–7.6)], diabetes mellitus [HR 4.2, 95%CI (2.4–7.4)] at pre-treatment were associated with HCC occurrence. HCC patients in the DAAs induced SVR group had a higher prevalence of NAFLD as compared with those in the PR induced SVR group, 62% (18/29) vs 28% (7/25), p = 0.026. A nomogram formulated with the above six independent variables had a Concordance-Index of 0.835 (95% CI 0.783–0.866).

Conclusion

Underlying NAFLD is associated with increased incidence of HCC in chronic HCV patients post-SVR, particularly in those treated with DAA.

•

Patients with chronic hepatitis C infection are still at risk of HCC after achieving sustained virus clearance (SVR).

•

Non-alcoholic liver disease (NAFLD) is emerging as an important risk factor for hepatocellular carcinoma.

•

Underlying NAFLD is associated with increased incidence of HCC in patients with chronic HCV infection after sustained virologic response SVR.

Intrahepatic De Novo Tumors in Liver Recipients are Highly Associated With Recurrent Viral Hepatitis

BACKGROUND/AIMS

Long-term survival of liver transplant recipients is endangered by tumorigenesis at different sites. Little is known about primary de novo tumors developing in the graft.

METHODS

We analyzed the follow-up data of 2731 liver recipients that were transplanted between 1988 and 2019 at our institution (Charité - Universitätsmedizin Berlin, Department of Surgery). All cases with new intrahepatic tumors during follow-up were identified.

RESULTS

A total of nine patients were diagnosed at a median of 16 years (range, 2-24 years) after surgery. Eight patients presented with hepatocellular carcinoma (HCC), and one patient presented with epithelioid hemangioendothelioma (EHE). All eight HCC patients had a recurrence of the initial disease that had caused liver failure before transplantation. This was associated with viral reinfection with either HCV or HBV in seven cases. Of the nine patients, three underwent surgical resection and only one patient was alive at data abstraction.

CONCLUSION

Intrahepatic de novo neoplasms in the liver graft need to be considered in the long-term follow-up of liver recipients and were strongly associated with recurrent viral hepatitis in our study. Although prognosis of this rare complication is generally poor, patients may benefit from surgical resection of localized disease.

Features of resistance-associated substitutions after failure of multiple direct-acting antiviral regimens for hepatitis C

Background & Aims

We aimed to clarify the features of resistance-associated substitutions (RASs) after failure of multiple interferon (IFN)-free regimens in HCV genotype 1b infections.

Methods

A total of 1,193 patients with HCV for whom direct-acting antiviral (DAA) treatment had failed were enrolled from 67 institutions in Japan. The RASs in non-structural protein (NS)3, NS5A, and NS5B were determined by population sequencing.

Results

Failure of 1, 2, and 3 regimens was observed in 1,101; 80; and 12 patients, respectively. Among patients with failure of 1 regimen, Y56H and D168V in NS3 were more frequently detected after failure of paritaprevir, whereas D168E was more frequently detected after failure of regimens including asunaprevir. R30H and L31-RAS in NS5A were frequently detected after failure of regimens including daclatasvir. The prevalence of Y93-RAS was high irrespective of the regimen. S282T RAS in NS5B was detected in 3.9% of ledipasvir/sofosbuvir failures. The prevalence of D168-RAS increased significantly according to the number of failed regimens (p <0.01), which was similar to that seen with L31-RAS and Y93-RAS. The prevalence of patients with RASs in either NS3 or NS5A, or in both, increased significantly with increasing numbers of failed regimens. The P32del, which is unique to patients for whom DAA had failed, was linked to the absence of Y93H, the presence of L31F, and previous exposure to IFN plus protease inhibitor regimens.

Conclusions

Failure of multiple DAA regimens can lead to the generation of multiple RASs in the NS3 and NS5A regions of the HCV 1b genome. These mutations contribute to viral resistance to multiple treatment regimens and, therefore, should be considered during decision making for treatment of chronic HCV.

Lay summary

Resistance-associated substitutions (RAS) in the genome of the hepatitis C virus are 1 of the major causes for failed treatment. We investigated RASs after failure of various treatments for chronic hepatitis C, and found that more complicated RASs accumulated in the viral genome with successive failed treatments. The highly resistant P32del RAS at NS5A region was uniquely found in patients for whom DAA treatments had failed, and was linked to the presence and absence of specific RASs.

Chronic Hepatitis C: Do Generics Work as Well as Branded Drugs?

India has a large share of the hepatitis C virus (HCV) burden of the world. Unsafe medical practices and blood transfusions are the leading modes of transmission of HCV in India. The commonest HCV genotype in India is genotype 3 followed by genotype 1. While directly acting antivirals (DAAs) agents have become available at reasonable rates in India, cost of therapy remains a major barrier for control of HCV in India. Generic DAAs have been proven to be cost-saving in prior studies. We examined data from various studies in India and elsewhere using generic DAAs, and evaluated whether they are equally efficacious as the branded drugs. Since the availability of generic DAAs in the Indian market, there is a lot of real life data as well as prospective studies in special patient populations such as hematological disorders (thalassemia and hemophilia), chronic kidney disease, hemodialysis patients, post liver and renal transplant patients on immunosuppression, intravenous drug users, confections and other high risk groups. Control of HCV infection in India requires multi pronged approach. There is a need to formulate a health educational curriculum targeting not only the high-risk population but also the general population regarding the transmission of HCV. Adopting the dual approach of treating the old cases (decreasing the reservoir pool of HCV) and decreasing the incidence of new ones would help curtail the disease and decrease liver related mortality. In this scenario, the role of efficacious low cost generic medications is essential.

Sofosbuvir and Ribavirin for 24 Weeks Is An Effective Treatment Option for Recurrent Hepatitis C Infection After Living Donor Liver Transplantation

BACKGROUND

Recurrent hepatitis C virus (HCV) has been a serious problem after liver transplantation (LT). We report our experience of 24-week therapy with sofosbuvir (SOF) and ribavirin (RBV) in post-LT recurrent HCV in living donor liver transplantation (LDLT) setting in South Asia.

METHODS

Data from all patients treated for post-transplantation HCV recurrence in a single center were analyzed. Treatment regimen was 24 weeks of SOF 400 mg daily and RBV (starting at 800 mg daily, increased as tolerated). Sustained virological response (SVR) was assessed 12 weeks and 24 weeks after completion of treatment.

RESULTS

63 patients (median age 52 [range 30-69] years; 80% males) were treated. Most (76.2%) were treatment experienced and predominant HCV genotype was 3 (77.7%) followed by 1 (20.6%). Median transient elastography (Fibroscan) score was 7 (range 3-11) kPa and none of the patients had cirrhosis. SVR12 was achieved in 60 of 63 patients (95.2%) while SVR24 was noted in 59 (93.7%). SVR12 rates were as good in genotype-3 as in genotype-1. Older age, longer period after transplantation, higher Fibroscan value and higher need for erythropoietin were likely to be associated with relapse. Adverse effects were noted in 34 patients and weakness and fatigue were the commonest side effects. Significant drop in hemoglobin (<8 g/dL) was seen in 6 patients.

CONCLUSIONS

SOF + RBV combination therapy for 24 weeks was safe and effective in treatment of for post-LT recurrent HCV in a single LT center and remains relevant due to its low cost and lack of drug interactions.

Potential Liver Transplant Recipients with Hepatitis C: Should They Be Treated Before or After Transplantation?

Treatment of hepatitis C virus (HCV) with newer directly acting antivirals (DAAs) and lead to sustained viral response (SVR) in majority of patients and SVR has been documented to be associated with reversal of liver cirrhosis. The improved SVR rates and safety profiles of DAAs have led to the treatment of patients with decompensated cirrhosis awaiting liver transplantation (LT). Several clinical trials of DAAs in decompensated HCV patients have recently demonstrated SVR rates above 80%, which have been associated with significant improvements, in the Child-Pugh-Turcotte scores/or model for end-stage liver disease scores in a proportion of patients. Moreover, it has been shown that HCV RNA becomes negative after 2-4 weeks of treatment, and those who are transplanted after becoming HCV RNA negative will be have very low the risk of HCV recurrence after transplantation. Some of the patients may have reached the "point of no return" and may proceed to worsening of decomposition over time. To avoid the risk of worsening, there is an additional option of treating these patients after LT should they develop recurrent HCV infection. Currently there are no guidelines as to select patients who would benefit from treatment prior to LT as opposed to those who will be better off being treated after the transplant surgery. The article discusses a possible approach for such selection.

Indian National Association for Study of the Liver (INASL) Guidance for Antiviral Therapy Against HCV Infection: Update 2016

India contributes significantly to the global burden of HCV. While the nucleoside NS5B inhibitor sofosbuvir became available in the Indian market in March 2015, the other directly acting agents (DAAs), Ledipasvir and Daclatasvir, have only recently become available in the India. The introduction of these DAA in India at a relatively affordable price has led to great optimism about prospects of cure for these patients as not only will they provide higher efficacy, but combination DAAs as all-oral regimen will result in lower side effects than were seen with pegylated interferon alfa and ribavirin therapy. Availability of these newer DAAs has necessitated revision of INASL guidelines for the treatment of HCV published in 2015. Current considerations for the treatment of HCV in India include the poorer response of genotype 3, nonavailability of many of the DAAs recommended by other guidelines and the cost of therapy. The availability of combination DAA therapy has simplified therapy of HCV with decreased reliance of evaluation for monitoring viral kinetics or drug related side effects.

Indian National Association for Study of the Liver (INASL) Guidance for Antiviral Therapy Against HCV Infection in 2015

Overall prevalence of HCV infection in India has been estimated to be approximately 1.3% in the general population. Recent introduction of sofosbuvir in India at a relatively affordable price has led to great optimism about prospects of cure for these patients. This drug is likely to form the backbone of current and future treatment regimes for HCV infection, displacing pegylated interferon. Availability of directly acting antiviral drugs (DAAs) has necessitated revision of INASL guidelines for the treatment of HCV published in 2014, as has happened across the world. Current considerations for the treatment of HCV in India include the poorer response of genotype 3, nonavailability of many of the DAAs recommended by other guidelines and the cost of therapy. Since only one DAA, sofosbuvir, is available in India, only two sofosbuvir-based regimes are possible: either dual drug therapy in combination with ribavirin alone for 6 months or triple drug therapy in combination with ribavirin and pegylated interferon for 3 months. The utility of these regimes in various situations has been discussed. Availability of a few other newer DAAs, expected in 2016, is expected to lead to more widespread use of these agents. Current guidance will be updated once newer DAAs, newer evidence with DAAs and 'real-life experience' with use of DAAs accumulate in India.

Interference of HCV replication by cell penetrable human monoclonal scFv specific to NS5B polymerase

A new class of hepatitis C virus (HCV)-targeted therapeutics that is safe, broadly effective and can cope with virus mutations is needed. The HCV's NS5B is highly conserved and different from human protein, and thus it is an attractive target for anti-HCV therapeutics development. In this study, NS5B bound-phage clones selected from a human single chain variable antibody fragment (scFv) phage display library were used to transform appropriate E. coli bacteria. Two scFv inhibiting HCV polymerase activity were selected. The scFvs were linked to a cell penetrating peptide to make cell penetrable scFvs. The transbodies reduced the HCV RNA and infectious virus particles released into the culture medium and inside hepatic cells transfected with a heterologous HCV replicon. They also rescued the innate immune response of the transfected cells. Phage mimotope search and homology modeling/molecular docking revealed the NS5B subdomains and residues bound by the scFvs. The scFv mimotopes matched residues of the NS5B, which are important for nucleolin binding during HCV replication, as well as residues that interconnect the fingers and thumb domains for forming a polymerase active groove. Both scFvs docked on several residues at the thumb armadillo-like fold that could be the polymerase interactive sites of other viral/host proteins for the formation of the replication complex and replication initiation. In conclusion, human transbodies that inhibited HCV RdRp activity and HCV replication and restored the host innate immune response were produced. They are potentially future interferon-free anti-HCV candidates, particularly in combination with other cognates that are specific to NS5B epitopes and other HCV enzymes.

Oxidized Low-Density Lipoprotein Is a Novel Predictor of Interferon Responsiveness in Chronic Hepatitis C Infection

BACKGROUND & AIMS

Hepatitis C virus (HCV) cell entry is mediated by several cell surface receptors, including scavenger receptor class B type I (SR-BI). Oxidized low density lipoprotein (oxLDL) inhibits the interaction between HCV and SR-BI in a noncompetitive manner. We tested whether serum oxLDL levels correlate with sustained virologic response (SVR) rates after interferon-based treatment of chronic hepatitis C.

METHODS

Baseline oxLDL was determined in 379 participants with chronic HCV genotype 1 infection from the INDIV-2 study using a commercial enzyme-linked immunosorbent assay. The mechanistic in vitro studies used full-length and subgenomic HCV genomes replicating in hepatoma cells.

RESULTS

In the multivariate analysis, oxLDL was found to be an independent predictor of SVR. Oxidized LDL did not correlate with markers of inflammation (alanine transaminase, ferritin), nor was serum oxLDL affected by exogenous interferon administration. Also, oxLDL did not alter the sensitivity of HCV replication to interferon. However, oxLDL was found to be a potent inhibitor of cell-to-cell spread of HCV between adjacent cells in vitro. It could thus reduce the rate at which new cells are infected by HCV through either the cell-free or cell-to-cell route. Finally, serum oxLDL was significantly associated with the estimated infected cell loss rate under treatment.

CONCLUSIONS

Oxidized LDL is a novel predictor of SVR after interferon-based therapy and may explain the previously observed association of LDL with SVR. Rather than being a marker of activated antiviral defenses it may improve chances of SVR by limiting spread of infection to naive cells through the cell-to-cell route.

Hepatitis C virus treatment in the 'real-world': how well do 'real' patients respond?

BACKGROUND

Published clinical trials of the treatment of HCV are largely multicentre prospective pharmaceutical trials. Patients in clinical trials tend to have more favorable outcomes than patients in the 'real-world', due to strict patient selection and differences in treatment conditions and available resources.

OBJECTIVES

To assess the outcomes of Hepatitis C infected patients treated at the Barwon Health Liver Clinic with combination Pegylated interferon (PEG-IFN) and Ribavirin (RBV) therapy and to determine factors associated with a treatment response.

METHODS

Retrospective review of patients who received treatment for Hepatitis C at our institution's Liver Clinic from January 2001-September 2011. Patient demographics, comorbidities, treatment-related parameters and side effects were extracted from medical records and analyzed.

RESULTS

A total of 190 patients (120 male, 70 female) with a mean age of 42.8 years (range 20-68 years) commenced treatment. The most common genotype was genotype 3 (48.9%), followed by genotype 1 (42.6%). 150 of 190 patients (78.9%) completed treatment and had end of treatment data available. 107 of 182 patients, (58.8%) for whom sustained virologic response (SVR) rate data was available achieved an SVR. Overall response rates were; 46.9%, 68.8% and 62.4% in genotypes 1, 2 and 3 respectively. The response rate was significantly lower in 29 patients with documented cirrhosis (20.7%). Age, diabetes and alcohol abuse did not predict treatment response in our cohort. Side effects reported in 81.6% of patients included general malaise, hematological disturbance and psychiatric issues, and necessitated cessation of therapy in 16 patients (8.4%) and dose reduction in 26 patients (13.7%).

CONCLUSIONS

Response rates to combination PEG-IFN and RBV therapy at our institution are comparable to other 'real-world' and pharmaceutical registration trials. Side effects of combination therapy were prominent but resulted in fewer discontinuations of therapy compared to pharmaceutical trials.

The antiviral effect of jiadifenoic acids C against coxsackievirus B3

Coxsackievirus B type 3 (CVB3) is one of the major causative pathogens associated with viral meningitis and myocarditis, which are widespread in the human population and especially prevalent in neonates and children. These infections can result in dilated cardiomyopathy (DCM) and other severe clinical complications. There are no vaccines or drugs approved for the prevention or therapy of CVB3-induced diseases. During screening for anti-CVB3 candidates in our previous studies, we found that jiadifenoic acids C exhibited strong antiviral activities against CVB3 as well as other strains of Coxsackie B viruses (CVBs). The present studies were carried out to evaluate the antiviral activities of jiadifenoic acids C. Results showed that jiadifenoic acids C could reduce CVB3 RNA and proteins synthesis in a dose-dependent manner. Jiadifenoic acids C also had a similar antiviral effect on the pleconaril-resistant variant of CVB3. We further examined the impact of jiadifenoic acids C on the synthesis of viral structural and non-structural proteins, finding that jiadifenoic acids C could reduce VP1 and 3D protein production. A time-course study with Vero cells showed that jiadifenoic acids C displayed significant antiviral activities at 0-6 h after CVB3 inoculation, indicating that jiadifenoic acids C functioned at an early step of CVB3 replication. However, jiadifenoic acids C had no prophylactic effect against CVB3. Taken together, we show that jiadifenoic acids C exhibit strong antiviral activities against all strains of CVB, including the pleconaril-resistant variant. Our study could provide a significant lead for anti-CVB3 drug development.

Treatment algorithms for managing hepatocellular carcinoma

Early diagnosis and aggressive therapy improves outcome in hepatocellular carcinoma (HCC). Several potentially curative as well as palliative treatment options are available for patients. The choice of therapy is influenced by factors such as extent of tumor and severity of underlying liver dysfunction as well as availability of resources and of expertise. A systematic, algorithmic approach would ensure optimal therapy for each patient and is likely to improve outcomes. Even after receiving therapy for HCC, patients remain at risk for recurrent HCC as well as progression of underlying cirrhosis. Proper assessment and monitoring is needed for the underlying liver disease, which may progress to liver failure and have a major impact on long-term survival. Comprehensive care for patients with cirrhosis includes interventions such as antiviral therapy for HBV and HCV, abstention from alcohol, management of fatty liver disease, endoscopic surveillance and treatment for complications of portal hypertension and, if indicated, immunization against HAV and HBV. An algorithmic approach is useful for choosing the most appropriate treatment option for the individual patient from among the various options that are available. The general consensus is that the BCLC system should be preferred for staging HCC as it is useful in predicting outcomes and planning treatment. The BCLC system classifies patients with HCC into five categories: very early, early, intermediate, advanced, and terminal. It incorporates data on tumor status (number and size of nodules, vascular invasion, extra-hepatic spread), liver function (CTP status, presence of portal hypertension) and overall health status (constitutional symptoms, cancer symptoms, performance status). Treatment allocation according to sub-class of patients is a merit of the BCLC system; a few limitations have been noted, particularly with respect to patients with BCLC stage B and C disease. The treatment algorithm as per BCLC system is summarized in this review.

The Distribution of Genotype and Allelic Frequency of IL28B Gene Polymorphism in Andhra Pradesh, India

BACKGROUND

The single nucleotide polymorphism (SNP) of IL28B gene on chromosome 19, encoding for the interferon (IFN)-λ-3 is strongly associated with treatment response to pegylated-IFN and ribavirin in patients infected with different genotypes of hepatitis C virus (HCV). Difference between ethnicity and treatment response rates suggesting a key role of host genetics. The IL28B polymorphism (rs12979860C/T) shows a marked differential distribution between racial groups.

AIM

The present study is aimed to evaluate genotype and allelic frequency of IL28B gene polymorphism (rs12979860C/T) in Andhra Pradesh, India.

METHODS

A total of 220 healthy controls were recruited for the study. The genotyping of SNP rs12979860C/T on IL28B gene was performed by polymerase chain reaction-direct sequencing method.

RESULT

The frequency of CC genotype was found to be significantly (59.09%) higher compared to CT (34.09%) and TT (6.81%) genotypes, respectively. The frequency of major allele C is 0.762 whereas minor allele T is 0.238.

CONCLUSION

The higher distribution of genotype 'CC' of SNP, rs12979860C/T of IL28B gene in study subjects is suggestive of better response of HCV patients to standard anti-HCV therapy.

Using decision tree learning to predict the responsiveness of hepatitis C patients to drug treatment

The recommended treatment for patients with chronic hepatitis C, pegylated interferon α (PEG-IFN-α) plus rebavirin (RBV), does not provide a sustained virologic response in all patients, especially those with hepatitis C virus (HCV) genotype 1. It is therefore important to predict whether or not a new patient with HCV genotype 1 will be cured by the recommended treatment. We propose a prediction method for a new patient using a decision tree learning model based on SNPs evaluated in a genome-wide association study. By the decision tree learning for 142 Japanese patients with HCV genotype 1 (78 with null virologic response and 64 with virologic response), we can predict with high probability (93%) whether or not a new patient with HCV will be helped by the recommended treatment.

A pharmacological profile of ribavirin and monitoring of its plasma concentration in chronic hepatitis C infection

Chronic hepatitis C (CHC) infection, usually an asymptomatic infection, has long-term serious complications such as cirrhosis, hepatocellular carcinoma, and end-stage liver disease requiring liver transplantation (LT). Several novel drugs against hepatitis C which form part of 'specifically targeted antiviral therapy for hepatitis C' (STAT-C) have been developed. These include NS3/4A protease inhibitors telaprevir, boceprevir, and nucleoside/non-nucleoside polymerase inhibitors (NS5A) which hold promise for future therapy. Despite the development of new anti-hepatitis C virus (HCV) drugs, ribavirin (RBV) remains the single most important drug to prevent relapse and is frequently included among newer regimens being developed with novel small molecule anti-HCV drugs. The current approved treatment is a combination therapy of once weekly subcutaneous pegylated-interferon (PEG-IFN)-α plus body-weight-based oral RBV regimen. The most significant dose-dependent side effect of RBV is hemolytic anemia warranting dose reduction or discontinuation in severe cases compromising sustained virological response (SVR). Monitoring RBV plasma concentration has been challenging due to its peculiar pharmacokinetics and has been done to predict both efficacy and toxicity. Herein, we review the pharmacological profile of RBV and the monitoring of its plasma concentration, monitoring in renal impairment, post-LT, and human immunodeficiency virus (HIV)-HCV co-infection in patients being treated with combination therapy of PEG-IFN-α and RBV.

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.

Interleukin 28B Polymorphisms and Hepatitis C-Translating the Association into Clinical Decision Making

Host genetic factors have long been suspected to play a role in predicting outcome and treatment response in hepatitis C virus (HCV) infection. This was confirmed recently by three landmark genome-wide association studies (GWAS) published in 2009, which identified single nucleotide polymorphisms near the interleukin (IL) 28B region that were more common in responders to treatment. There has subsequently been rapidly increasing data regarding the significance of the IL28B polymorphism not only in response to therapy but also in spontaneous clearance of acute HCV infection. This clinical association of Il28B genotype with HCV may lead to personalized HCV therapy, where the clinician may tailor the duration and type of therapy for an individual patient. This review summarizes the available data on the impact of IL28B polymorphisms on HCV infection and discusses the possible approach to translate this association into clinical decision making for the treatment of HCV infection.