Comparison of different HCV viral load and genotyping assays

Binding of GS-461203 and Its Halogen Derivatives to HCV Genotype 2a RNA Polymerase Drug Resistance Mutants

Hepatitis C Virus (HCV) is reported to develop GS-461203 resistance because of multiple mutations within the RNA-dependent RNA Polymerase (RdRp) of HCV. The lack of a high-resolution structure of these RdRp mutants in complex with GS-461203 hinders efforts to understand the drug resistance. Here we decipher the binding differences of GS-461203 in the wild type and mutated systems T179A or M289L of HCV RdRp Genotype 2a using homology modeling, molecular docking, and molecular dynamics simulation. Key residues responsible for GS-461203 binding were identified to be Arg48, Arg158, Asp318, Asp319, and Asp220, and that mutations T179A or M289L have caused conformational changes of GS-461203 in the RdRp active site. The affinities of GS-461203 were reduced in T179A system, but it became slightly stronger in the M289L system. Furthermore, we designed two new analogues of GS-461203 which encouragingly induced more stable interactions than GS-461203, and thus resulted in much better binding energies. This present study reveals how a single mutation, T179A or M289L, will modulate GS-461203 binding in HCV RdRp Genotype 2a, while introducing two novel analogues to overcome the drug resistance which may be good candidate for further experimental verification.

Phylogenetic Characterization of the 5' Untranslated Region of Untypable HCV Genotypes Circulating in Pakistan

INTRODUCTION

Commercial methods for HCV genotyping is challenged by the increased prevalence of untypable genotypes in Pakistan.

OBJECTIVE

The aim of the current study was to perform nucleotide sequencing of 5' UTR region for genotyping of viral isolates circulating in Peshawar, Pakistan.

METHODS

The total number of commercially untypable samples were 94 in which 18 samples were sequenced for the characterization of 5' UTR region. Post-sequencing analysis was performed for genotype identification (n = 18) and molecular phylogenetic analysis.

RESULTS

The current study reveals different genotypes, that is, 10/18 viral isolates were found to be genotype 3a (55.55%), 3 isolates (genotype 3b, 16.66%), 2 isolates (genotype 6h/6g, 11.11%), 2 (6g/d, 11.11%), and 1 sample (genotype 1c, 5.55%). In addition, genotype 3a is the dominant representative of HCV circulating in Pakistan and has been increasing across the country.

CONCLUSION

The current study also reveals that genotype 6 (2 were genotype 6h/6g and 2 were 6g/d) is also circulating in Pakistan and not restricted to South China and Hong Kong.

Management of HCV patients in cases of direct-acting antiviral failure

Introduction: Over 70 million people are infected with hepatitis C virus (HCV), increasing the risk of cirrhosis and hepatocellular carcinoma. Areas covered: Since the approval of the first interferon-free direct-acting antiviral (DAA) therapy in 2011, a number of DAAs have been approved, and HCV is now considered curable. Until recently, however, there were no clear guidelines on how to re-treat patients who fail DAA therapy. Current protease inhibitors (PIs) are generally unaffected by earlier resistance-associated variants (RAVs), but many NS5A inhibitors continue to have overlapping resistance profiles, and NS5A RAVs can persist even in the absence of DAAs. Expert opinion: Fortunately, RAVs affecting NS5B polymerase inhibitors are rare, making sofosbuvir a safe choice as the backbone of re-treatment therapies. Recent re-treatment guidelines that take into account genotype, fibrosis, treatment history, and RAV suggest that >90% of patients with prior treatment failures can be successfully re-treated with sofosbuvir/velpatasvir, sofosbuvir/velpatasvir/voxilaprevir or glecaprevir/pibrentasvir.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Prevalence of Hepatitis C virus genotypes in nine selected European countries: A systematic review

BACKGROUND

Hepatitis C virus (HCV) infection is a global health problem especially for its increasing level of mortality. Detailed knowledge of HCV genotypes prevalence has clinical relevance since the efficacy of therapies is impacted by genotypes and subtypes distribution. Moreover, HCV exhibits a great genetic variability regionally. To date, there are no published studies assessing HCV genotypes distribution in specific countries of the Mediterranean basin. The aim of this study was to review data published from 2000 to 2017 with the purpose to estimate genotypes distribution of HCV infection in nine European countries all located in the Mediterranean basin.

METHODS

A systematic research of peer-reviewed journals indexed in PubMed, Scopus, and EMBASE databases selected if containing data regarding distribution of HCV genotypes in nine selected European countries (Albania, Bosnia, Croatia, France, Greece, Italy, Montenegro, Slovenia, and Spain) was performed.

RESULTS

Genotype 1 is the most common (61.0%), ranging from 80.0% in Croatia to 46.0% in Greece, followed by genotype 3 (20.0%), varying from 38.0% in Slovenia to 7.0% and 8.0%, respectively, in Italy and in Albania and by genotype 4 (10.0%) that shows an increase of 1.1% with respect to data obtained till 2014 probably due to the increasing migrants arrivals to Southern Europe. G2, the fourth most frequent genotype (8.5%), particularly common in Italy (27.0%) and Albania (18.0%) might be probably introduced in Southern Italy as a result of Albanian campaign during Second World War and more and more increased by the migration flows from Albania to Italy in the 90s.

CONCLUSION

Epidemiology of HCV infection shows a high variability across the European countries that border the Mediterranean Sea. HCV genotyping is a relevant tool to monitor the dynamic process influenced by both evolving transmission trends and new migration flows on HCV scenario.

Nine-year distribution pattern of hepatitis C virus (HCV) genotypes in Southern Italy

INTRODUCTION

It has been greatly described that different hepatitis C virus (HCV) genotypes are strictly correlated to various evolution, prognosis and response to therapy during the chronic liver disease. Aim of this study was to outline the changes in the epidemiology of Hepatitis C genotypes in Southern Italy regions from 2006 to 2014.

MATERIAL/METHODS

Prevalence of HCV genotypes was analyzed in 535 HCV-RNA positive patients with chronic Hepatitis C infection, selected during the period 2012-2014, and compared with our previous data, referred to periods 2006-2008 and 2009-2011.

RESULTS

In all the three periods analyzed, genotype 1b is predominant (51.8% in 2006-08, 48.3% in 2009-11 and 54.4% in 2012-14) while genotype 2 showed an increase in prevalence (27.9% in 2006-08, 31.7% in 2009-11 and 35.2% in 2012-14) and genotypes 3a and 1a a decrease during the same period (6.8% in 2006-08, 4.7% in 2009-11 and 3.2% in 2012-14 and 7.9% in 2006-08, 4.7% in 2009-11 and 2.6% in 2012-14, respectively). Subtype 1b seems to be equally distributed between males and females (52.7% vs 56.6%) and the prevalence in the age range 31-40 years is significantly higher in the 2012-14 period than in both previous periods (53.8% vs. 16.6% in 2009-11, p< 0.001 and 13.4% in 2006-08, p < 0.001).

CONCLUSIONS

Genotype 1b is still the most prevalent, even if shows a significantly increase in the under 40 years old population. Instead, genotype 3a seems to have a moderate increase among young people. Overall, the alarming finding is the "returning" role of the iatrogenic transmission as risk factor for the diffusion of Hepatitis C infection.

Epidemiology of Hepatitis B Virus (HBV) and Hepatitis C Virus (HCV) Related Hepatocellular Carcinoma

Introduction

Hepatocellular carcinoma (HCC) is one of the most prevalent primary malignant tumors and accounts for about 90% of all primary liver cancers. Its distribution varies greatly according to geographic location and it is more common in middle and low- income countries than in developed ones especially in Eastern Asia and Sub Saharan Africa (70% of all new HCCs worldwide), with incidence rates of over 20 per 100,000 individuals.

Explanation

The most important risk factors for HCC are Hepatitis B Virus (HBV) infection, Hepatitis C Virus (HCV) infection, excessive consumption of alcohol and exposition to aflatoxin B1. Its geographic variability and heterogeneity have been widely associated with the different distribution of HBV and HCV infections worldwide.Chronic HBV infection is one of the leading risk factors for HCC globally accounting for at least 50% cases of primary liver tumors worldwide. Generally, while HBV is the main causative agent in the high incidence HCC areas, HCV is the major etiological factor in low incidence HCC areas, like Western Europe and North America.

Conclusion

HBV-induced HCC is a complex, stepwise process that includes integration of HBV DNA into host DNA at multiple or single sites. On the contrary, the cancerogenesis mechanism of HCV is not completely known and it still remains controversial as to whether HCV itself plays a direct role in the development of tumorigenic progression.

The changing epidemiology and aetiology of hepatocellular carcinoma from 1969 through 2013 in Alaska Native people

BACKGROUND & AIMS

Alaska Native people have an increased rate of hepatocellular carcinoma compared to the United States population. Viral hepatitis is a risk factor for malignancy and the leading cause of hepatocellular carcinoma in Alaska. With the introduction of hepatitis B immunization in 1982, as well as the emergence of hepatitis C virus in this population, the epidemiology and aetiology of hepatocellular carcinoma in Alaska have changed.

METHODS

Using the Alaska Native Tumor Registry, all cases of viral and non-viral hepatocellular carcinoma occurring from 1969 through 2013 were identified and reviewed. Incidence rates per 100 000 population were calculated for hepatocellular carcinoma overall and by aetiological category.

RESULTS

One hundred and fifty-two cases of hepatocellular carcinoma were identified in 148 Alaska Native persons. Overall tumour rate was 3.82 per 100 000 and did not change significantly over the study period. Hepatitis B-associated cases decreased significantly over the study period (P = 0.048) and were eliminated in persons under the age of 20. Hepatitis C-associated cases increased significantly (P < 0.001). Undetermined hepatocellular carcinoma rates also decreased (P = 0.034).

CONCLUSIONS

Overall hepatocellular carcinoma rates in Alaska Native people remained stable over the study period, but the epidemiology and aetiology are changing. Two decades after routine hepatitis B immunization, the hepatocellular carcinoma age distribution has shifted to cases presenting later in life. This is consistent with an ageing hepatitis B-infected population with no new infected young persons' coming into the population, as well as the emergence of hepatitis C in adults.

Global epidemiology of hepatitis C virus infection: An up-date of the distribution and circulation of hepatitis C virus genotypes

AIM

To review Hepatitis C virus (HCV) prevalence and genotypes distribution worldwide.

METHODS

We conducted a systematic study which represents one of the most comprehensive effort to quantify global HCV epidemiology, using the best available published data between 2000 and 2015 from 138 countries (about 90% of the global population), grouped in 20 geographical areas (with the exclusion of Oceania), as defined by the Global Burden of Diseases project (GBD). Countries for which we were unable to obtain HCV genotype prevalence data were excluded from calculations of regional proportions, although their populations were included in the total population size of each region when generating regional genotype prevalence estimates.

RESULTS

Total global HCV prevalence is estimated at 2.5% (177.5 million of HCV infected adults), ranging from 2.9% in Africa and 1.3% in Americas, with a global viraemic rate of 67% (118.9 million of HCV RNA positive cases), varying from 64.4% in Asia to 74.8% in Australasia. HCV genotype 1 is the most prevalent worldwide (49.1%), followed by genotype 3 (17.9%), 4 (16.8%) and 2 (11.0%). Genotypes 5 and 6 are responsible for the remaining < 5%. While genotypes 1 and 3 are common worldwide, the largest proportion of genotypes 4 and 5 is in lower-income countries. Although HCV genotypes 1 and 3 infections are the most prevalent globally (67.0% if considered together), other genotypes are found more commonly in lower-income countries where still account for a significant proportion of HCV cases.

CONCLUSION

A more precise knowledge of HCV genotype distribution will be helpful to best inform national healthcare models to improve access to new treatments.

Cutting the gordian knot-development and biological relevance of hepatitis C virus cell culture systems

Worldwide approximately 180 million people are chronically infected with hepatitis C virus (HCV). HCV isolates exhibit extensive genetic heterogeneity and have been grouped in six genotypes and various subtypes. Additionally, several naturally occurring intergenotypic recombinants have been described. Research on the viral life cycle, efficient therapeutics, and a vaccine has been hampered by the absence of suitable cell culture systems. The first system permitting studies of the full viral life cycle was intrahepatic transfection of RNA transcripts of HCV consensus complementary DNA (cDNA) clones into chimpanzees. However, such full-length clones were not infectious in vitro. The development of the replicon system and HCV pseudo-particles allowed in vitro studies of certain aspects of the viral life cycle, RNA replication, and viral entry, respectively. Identification of the genotype 2 isolate JFH1, which for unknown reasons showed an exceptional replication capability and resulted in formation of infectious viral particles in the human hepatoma cell line Huh7, led in 2005 to the development of the first full viral life cycle in vitro systems. JFH1-based systems now enable in vitro studies of the function of viral proteins, their interaction with each other and host proteins, new antivirals, and neutralizing antibodies in the context of the full viral life cycle. However, several challenges remain, including development of cell culture systems for all major HCV genotypes and identification of other susceptible cell lines.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of PEGIFN and RBV is the most effective therapy for patients with chronic hepatitis C. Although more than half of all patients are able to achieve SVR, a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. An approach in the management of these patients is to identify factors that could have led to the NR or relapse and that could be corrected before or during a second course of therapy. Because fibrosis progression occurs slowly over decades for many patients with chronic hepatitis C, avoiding alcohol or other factors that could lead to fibrosis progression may be sufficient for the vast majority of patients. Other options that could be considered in patients who have more advanced disease include retreating with one of several new antiviral agents; retreating with higher doses of IFN or PEGIFN and RBV; or using IFN, PEGIFN, or RBV monotherapy long-term as maintenance therapy. The safety and efficacy of these approaches is being evaluated in numerous clinical trials.

Development of a TaqMan assay for the six major genotypes of hepatitis C virus: comparison with commercial assays

A quantitative real-time PCR assay was developed that detects genomic RNA from reference strains representing the six major genotypes of hepatitis C virus (HCV) with equal sensitivity and accurately measured HCV RNA in JFH1 HCV-infected Huh7.5 cells. The method is indirectly calibrated to the first international (WHO 96/790) HCV standard preparation and has a linear dynamic range of 10(2.6)-10(6.5) IU/ml. In addition, the inter- and intra-assay precision were approximately 3% CV and <2% CV, respectively. Comparison with results obtained by commercially available HCV RNA Nucleic Acid Technology kits (Versant HCV RNA 3.0 b-DNA and Amplicor HCV Monitor), that also employ the WHO standard, allowed validation of the TaqMan assay against all major HCV genotypes. Both commercial methods detected HCV RNA over a wide dynamic range, but showed a consistent difference of about 0.3 log10 when evaluating samples of different HCV genotypes. The genome titers obtained with the three methods correlated with the infectivity titers previously determined for the HCV reference strains. TaqMan assays have become an essential tool to follow viral load in clinical samples and cell culture-based experiments and this technology offers significant advantages in linear dynamic range, sensitivity and customization.

Determination of the hepatitis C virus subtype: comparison of sequencing and reverse hybridization assays

BACKGROUND

Hepatitis C virus (HCV) genotyping and accurate subtyping is becoming increasingly relevant to epidemiological studies, clinical management, pathogenicity, and vaccine development.

METHODS

The TRUGENE HCV 5'NC Genotyping Kit, the new VERSANT HCV Genotype 2.0 Assay (LiPA), and a new laboratory-developed HCV NS5b sequencing assay designed for automated sequencing of the HCV NS5b region were used. Clinical samples and a molecular diagnostics HCV genotyping proficiency program panel were used to determine accuracy and differentiate performance characteristics of the three methods.

RESULTS

All amplified samples from among the members of a HCV genotyping proficiency program panel that contained a single HCV genotype were subtyped correctly using all three HCV genotyping assays. With the TRUGENE HCV 5'NC Genotyping Kit, the HCV subtype was determined in 357 of 441 of routine clinical samples. When the 84 samples with only genotype results were retested with the VERSANT HCV Genotype 2.0 Assay (LiPA), 61 could be further subtyped accurately. With the new laboratory-developed HCV NS5b sequencing assay, all 84 could be subtyped accurately.

CONCLUSIONS

The two new methods show advantages over the routinely used TRUGENE HCV 5'NC Genotyping Kit in terms of genotyping and subtyping accuracy by utilizing part of the HCV core region and NS5b region, respectively.

Molecular methods of hepatitis C genotyping

Hepatitis C virus is an RNA virus that is associated with chronic infection in the majority of people infected. Chronic infection with hepatitis C virus is the cause of significant morbidity and mortality worldwide and is associated with a large spectrum of liver disease including cirrhosis and hepatocellular carcinoma. End-stage liver disease due to chronic hepatitis C virus infection is currently the leading indication for liver transplantation in the USA. Hepatitis C virus genotyping of viral isolates circulating in the blood during chronic infection has become an important part of hepatitis C virus monitoring in chronically infected patients, and is useful as a prognostic indicator and to direct duration of therapy. This review will summarize information on hepatitis C genotyping, describe the limitations of current commercially available methods, give information on more recently developed methods, and provide a look to the future in terms of where advances in hepatitis C virus genotyping assays need to be made.

Hepatitis and human immunodeficiency virus co-infection among injection drug users in Los Angeles County, California

This study examined the prevalence of hepatitis A (HAV), B (HBV), C (HCV), and Human Immunodeficiency Virus (HIV) co-infection among Injection Drug Users (IDUs) in Los Angeles County, California, and predictors of multiple infections in this population. Six hundred seventy-nine IDUs were recruited from October 2002 through June 2004. Participants completed questionnaires to elicit demographic, drug and sex risk information, and were tested for hepatitis A, B, C and HIV.A linear regression model predicting the total number of infections (0 to 4 possible) was constructed. Significant associations were found between HAV and HBV infection, HAV and HCV infection, and HBV and HCV infection. Predictors of total co-infections included age of first injection, lifetime years in jail, and Hispanic ethnicity. Latinos had the highest proportion of HAV and HBV co-infection with HCV. The total number of co-infections, especially those co-infected with all three of the hepatitis infections, was unexpectedly high.

Cocirculation of measles virus genotype B2 and B3.1 in Central African Republic during the 2000 measles epidemic

Many African countries have begun implementation of national programs to eliminate measles by the year 2015. However, measles continues to be endemic in Africa. This study describes the first molecular epidemiological study of measles virus circulating in Central African Republic. Two hundred and ten blood samples were tested for measles IgM. Sixty-seven urine samples were collected during measles outbreak in Bangui in 2000 and 2004 and used for genotyping studies. Two different methods were used to determine measles virus genotypes; the recently described real-time PCR-based method and the nucleotide sequencing and phylogenetic analysis methods. These tests revealed the cocirculation of two distinct viruses in Bangui. The proposed subgroup of the B3 genotype, B3.1 was found in 14 samples. This virus has been found in other neighboring countries. More surprising, genotype B2 was found in samples from four patients. The first measles genotype B2 viruses were isolated in Gabon in 1984, but have not been detected until recently when they were identified during a measles outbreak in 2003 in South Africa. This suggests that the circulation of measles genotype B2 has continued in Central Africa during the last 20 years. This study provides the baseline for genetic surveillance of measles virus in Central African Republic. Knowledge of currently circulating measles virus genotype in Central African Republic will help in monitoring the success of measles elimination program.

TRUGENE sequencing versus INNO-LiPA for sub-genotyping of HCV genotype-4

Hepatitis C virus genotypes and subtypes determination is an important factor for understanding the epidemiology of the virus, in the pre-treatment evaluation of the patients and in defining better treatment strategies. In the present study, we compared two commercially available assays for HCV genotyping: the reverse hybridization based Innogenetics INNO-LiPA HCV II and the direct sequencing by TRUGENE assay. The study included 31 HCV-RNA positive Egyptian patients; 18 patients with chronic active hepatitis, 8 with HCC, and 5 with cirrhosis. Using the TRUGENE genotyping test, all the samples had genotype 4 (100%) and subtyped as 4a in 18/31(58%), 4c in 10/31 (32%), 4e in 1/31 (3%), 4a/c in 1/31 (3%), and 4g in 1/31 (3%). Using the INNO-LiPA assay, 30 samples had genotype 4 (97%), and 1 sample had genotype 1e (3%). One sample showed mixed infection with type 4f and type 1. Only six samples were subtypable by INNO-LiPA, three were genotype 4c/d, and the other three were 4f, 4e, and 1e. Seven samples gave reactivity in the INNO-LiPA of lines 5, 6, 16, 17, 18, which are considered untypable by the interpretation chart but considered to be a rare HCV genotype 4 by the manufacturer. At the genotype level, there was a 97% concordance between TRUGENE sequencing and INNO-LiPA, but at the subtype level the concordance rate was 3% only. We conclude that the TRUGENE genotyping assay is a reliable test for HCV genotyping for the detection of major types and subtypes detection, while INNO-LiPA is a good test at the genotype level but unreliable for subtyping especially in the Egyptian population. This is mainly due to the high diversity of genotype 4, which is the most prevalent genotype in Egypt.

Serum alpha-fetoprotein levels in patients with advanced hepatitis C: results from the HALT-C Trial

BACKGROUND/AIMS

Alpha-fetoprotein (AFP) has been useful in the diagnosis of hepatocellular carcinoma (HCC) but lacks specificity. We assessed serum AFP among patients with chronic hepatitis C and advanced fibrosis to establish predictors of AFP elevations and changes with antiviral therapy.

METHODS

Serum AFP was measured at baseline and on therapy in patients in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C). AFP levels were correlated with patient demographic and clinical features.

RESULTS

Baseline AFP was > or = 20 ng/mL in 191 of 1145 patients (16.6%). Mean AFP values were significantly higher in patients with cirrhosis than in those with bridging fibrosis (22.5 vs. 11.4 ng/mL, P < 0.0001). Factors independently associated with raised serum AFP in patients with cirrhosis were female gender, black race, decreased platelet count, increased serum AST/ALT ratio, serum ferritin, and Mallory bodies in liver biopsies. Serum AFP levels decreased significantly during therapy with pegylated interferon alpha-2a and ribavirin. HCC was identified in six subjects, only three of whom had AFP > 20 ng/mL.

CONCLUSIONS

Among patients with advanced chronic hepatitis C, serum AFP values are frequently elevated, even in the absence of HCC. Factors associated with raised AFP include severity of liver disease, female gender and black race. Serum AFP levels decline during antiviral therapy.

Nucleic acid testing for viral burden and viral genotyping

BACKGROUND

Molecular diagnostics plays an important role in the diagnosis and clinical management of a wide array of infectious diseases.

METHODS

Advances in molecular technology and methods of detecting nucleic acid sequences have revolutionized the field of virology. These developments are reflected by the rapid diagnosis and monitoring of viral agents as well as assessment of clinical disease associated with viral infections. In addition to many commercially available molecular based assays, many laboratories offer in-house developed assays for a variety of viral targets. The introduction of real-time PCR technology has made a large impact on virology testing.

CONCLUSIONS

The role of real-time PCR for the diagnosis of viral infections is enhanced by the accuracy, rapidity and ability to quantitate viral target sequences.

Approach to the management of patients with chronic hepatitis C who failed to achieve sustained virologic response

The combination of peginterferon and ribavirin is the most effective therapy for patients with chronic hepatitis C virus (HCV) infection. Although more than half of all patients are able to achieve a sustained virologic response (SVR), a significant proportion of patients, particularly those with genotype 1, fail to have undetectable HCV RNA during treatment or relapse after completing therapy with return of detectable HCV RNA. The management of these patients creates a formidable challenge. This article outlines various strategies for patients who have failed to achieve SVR and discusses the merits of different approaches to management.

Results of a hepatitis C general transfusion lookback program for patients who received blood products before July 1992

BACKGROUND

The Centers for Disease Control and Prevention recommend hepatitis C virus (HCV) antibody (anti-HCV) screening for persons who received blood products before July 1992. A general transfusion lookback program was implemented to identify, counsel, and screen persons who received transfusions at the Alaska Native Medical Center between January 1980 and July 1992.

STUDY DESIGN AND METHODS

Hard-copy transfusion records data were entered, and available databases were queried to identify deceased patients and the mailing address of those living. Patients were notified by letter of their HCV risk and encouraged to seek counseling and testing. Serum samples were screened for anti-HCV and HCV RNA, and program costs were estimated.

RESULTS

Overall, 3169 transfusion recipients were identified, with 1356 (43%) living and targeted for notification. Of 764 patients notified and screened by this program, 41 (5%) were anti-HCV-positive and 19 (2%) were HCV RNA-positive. There was a higher probability of detecting anti-HCV with each subsequent increase of a transfusion event. Among 298 lookback patients, 33 percent were unaware of having received a blood transfusion. The estimated cost per person sent notification was US$57 and to detect an anti-HCV-positive case it was US$3146.

CONCLUSION

This general transfusion lookback program successfully notified and screened patients at a reasonable cost. Further investigation would be helpful in determining the role these programs or other measures could play in promoting HCV screening in persons receiving transfusions before July 1992, especially among those who are unaware of their transfusion history.

Chronic Hepatitis C and Genotyping: The Clinical Significance of Determining HCV Genotypes

Chronic hepatitis C, attributed to infection with hepatitis C virus (HCV), is a global health problem. The overall prevalence of viral hepatitis worldwide is estimated to be 3–5% with over 175 million people infected with HCV. Clinically, HCV can establish a persistent, chronic infection contributing to progressive liver disease, including cirrhosis and hepatocellular carcinoma (HCC), requiring intensive treatment regimens, possible liver transplantation and long-term care. Due to the chronic nature of HCV infection and the tremendous burden on healthcare resources, clinicians and laboratorians have looked for key epidemiological, pathological and viral characteristics that may provide insight into disease progression, severity and response to therapy to permit the administration of effective therapeutic regimens as well as long-term management of infected individuals. Determination of viral genotype has been identified as one parameter that could provide direction in the clinical management of patients with chronic HCV infections. The following review provides background on determination of HCV genotypes and the relevance of viral genome characterization in the current clinical setting.

Inter-laboratory comparison of qualitative and quantitative detection of hepatitis C (HCV) virus RNA in diagnostic virology: a multicentre study (MS) in Italy

BACKGROUND

The importance of the standardisation of nucleic acid amplification technology (NAT) assays for the detection of hepatitis C virus RNA is well known today, as many studies carried out in different European countries attest. The results of a previous study performed in Italy (J. Clin. Virol. 1 (2003) 83) by the Italian Society of Clinical Microbiology (AMCLI) showed that the use of external reference standards and of multicentre collaborative studies significantly improves laboratory performance for the qualitative evaluation of HCV RNA.

OBJECTIVES

the AMCLI organised a new study on the standardisation of both the qualitative and the quantitative evaluation of HCV RNA with NAT in order to improve the implementation of the diagnostic methods for HCV RNA detection.

STUDY DESIGN

seventeen diagnostic centres of major Italian Hospitals participated in this quality control study. The study consisted of testing three panels, each made up of 10 coded samples including negative and positive samples. Positive samples contained four levels of HCV RNA (genotype 1).

RESULTS AND CONCLUSION

Seven out of 510 qualitative results obtained were incorrect (1.4%), two false negative and five false positive. The results gave a sensitivity of 99.5% and a specificity of 95.8%. Regarding quantitative tests, the geometric mean (GM) and standard deviation (S.D.) could be calculated only for the three highest HCV RNA levels. The percentage of results within the range of GM +/- 0.5 log(10) varied from 91% to 100%. Some laboratories had some difficulty in the exact quantification of the lowest (3.00 log IU/ml) as well as of the highest viral levels (6.35 log IU/ml) values, very near to the limits of the dynamic range of the assays. The comparison of the results of this study with that previously carried out one confirms that a regular participation in external quality assessment (EQA) assures the achievement of a high proficiency level in the diagnosis of HCV infection.