Infection with hepatitis C virus genotype 4 in the United States

Hepatitis C treatment program in Maputo, Mozambique, the challenge of genotypes and key populations: A 5-year retrospective analysis of routine programmatic data

Background and Aims

Hepatitis C (HCV) programs face challenges, especially linked to key populations to achieve World Health Organization (WHO) goals of eliminating hepatitis. Médecins Sans Frontières and Mozambique's Ministry of Health first implemented HCV treatment in Maputo, in 2016 and harm reduction activities in 2017.

Methods

We retrospectively analyzed routine data of patients enrolled between December 2016 and July 2021. Genotyping was systematically requested up to 2018 and subsequently in cases of treatment failure. Sustainable virological response was assessed 12 weeks after the end of treatment by sofosbuvir-daclatasvir or sofosbuvir-velpatasvir.

Results

Two hundred and two patients were enrolled, with 159 (78.71%) males (median age: 41 years [interquartile range (IQR): 37.10, 47.00]). Risk factors included drug use (142/202; 70.29%). One hundred and eleven genotyping results indicated genotype 1 predominant (87/111; 78.37%). Sixteen patients presented genotype 4, with various subtypes. The people who used drugs and HIV coinfected patients were found more likely to present a genotype 1. Intention-to-treat analysis showed 68.99% (89/129) cure rate among the patients initiated and per-protocol analysis, 88.12% (89/101) cure rate. Nineteen patients received treatment integrated with opioid substitution therapy, with a 100% cure rate versus 59.37% (38/64) for initiated ones without substitution therapy (p < 0.001). Among the resistance testing performed, NS5A resistance-associated substitutions were found in seven patients among the nine tested patients and NS5B ones in one patient.

Conclusion

We found varied genotypes, including some identified as difficult-to-treat subtypes. People who used drugs were more likely to present genotype 1. In addition, opioid substitution therapy was key for these patients to achieve cure. Access to second-generation direct-acting antivirals (DAAs) and integration of HCV care with harm reduction are crucial to program effectiveness.

Prevalence and distribution of hepatitis C virus genotypes in Spain during the 2000-2015 period (the GEHEP 005 study)

We report the largest study on the prevalence and distribution of HCV genotypes in Spain (2000-2015), and we relate them with clinical, epidemiological and virological factors. Patients from 29 hospitals in 10 autonomous communities (Andalusia, Aragon, Castilla-Leon, Catalonia, Galicia, Canary Islands, Madrid Community, Valencian Community, Murcia Region and Basque Country) have been studied. Annual distribution of HCV genotypes and subtypes, as well as gender, age, transmission route, HIV and/or HBV coinfection, and treatment details were recorded. We included 48595 chronically HCV-infected patients with the following characteristics: median age 51 years (IQR, 44-58), 67.9% male, 19.1% HIV-coinfected, 23.5% HBV-coinfected. Parenteral transmission route was the most frequent (58.7%). Genotype distribution was 66.9% GT1 (24.9% subtype 1a and 37.9% subtype 1b), 2.8% GT2, 17.3% GT3, 11.4% GT4 and 0.1% GT5 and 0.02% GT6. LiPA was the most widely HCV genotyping test used (52.4%). HCV subtype 1a and genotypes 3 and 4 were closely associated with male gender, parenteral route of infection and HIV and HBV coinfection; in contrast, subtype 1b and genotype 2 were associated with female gender, nonparenteral route and mono-infection. Age was related to genotype distribution, and different patterns of distribution and biodiversity index were observed between different geographical areas. Finally, we describe how treatment and changes in transmission routes may have affected HCV genotype prevalence and distribution patterns. We present the most recent data on molecular epidemiology of hepatitis C virus in Spain. This study confirms that genotype distributions vary with age, sex, HIV and HBV coinfection and within geographical areas and epidemiological groups.

Global genotype distribution of hepatitis C viral infection among people who inject drugs

BACKGROUND & AIMS

Hepatitis C viral infection (HCV) after injection drug use is very prevalent. The kind of genotype determines the response to treatment. However, no systematic review update on the global genotype distribution of HCV in people who inject drugs (PWID) is currently available.

METHODS

A systematic review was performed by using the keywords: Genotype, Hepatitis C, Injection drug user/Intravenous drug user/Substance user/ PWID, Name of countries in Pubmed, Embase and PsycINFO. The results were compared with the review of Gower et al. in 2014, concerning the distribution of HCV genotypes in the general HCV population.

RESULTS

Using these keywords, 132 studies in 48 countries (from 1995 to 2015) were collected. After grading these results, the data of 48 studies were used to determine the distribution of genotypes in PWID. Genotype 1 is the most prevalent genotype all over the world in PWID. In Europe, genotypes 1, 3 and 4 are highly prevalent. In North and South America and in Australia genotype 1 and 3 are most prevalent. In Asia genotype 2 and 6, and Africa genotype 1a and 4 are mostly observed. Overall, the most important differences comparing with the general population are a lower prevalence of genotype 1b in the PWID population and higher prevalence of genotype 1a and 3.

CONCLUSIONS

There is a different prevalence of genotype distribution in PWID than in the general population. Genotype 3 is especially highly prevalent in the Western countries.

LAY SUMMARY

Hepatitis C viral infection after injection drug use is very prevalent. The most important genotype causing HCV infection in PWID globally is genotype 1, as is the case in the general population, but also genotype 3 is highly prevalent in PWID. Genotype 4 is most prevalent in Africa, spreading into Europe, whereas genotype 2 and 6 are more located in Asia. The most important difference comparing to the general population are generally lower prevalence of genotype 1b, and higher prevalence of genotype 1a and 3 in PWID. As the genotype nowadays still determines the treatment, and as there is a different genotype distribution than in the general population, it is important to identify the genotype also in PWID.

Assessment of interleukin 28B genotype as a predictor of response to combined therapy with pegylated interferon plus ribavirin in HCV infected Egyptian patients

BACKGROUND AND AIM

Single nucleotide polymorphisms (SNPs) of interleukin 28B (IL28B) gene is associated with spontaneous clearance and variable response to combined therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV) in chronic hepatitis C virus (HCV) infected patients. This study aimed at assessing the value of IL28B rs8099917 gene polymorphism in predicting sustained virological response (SVR) among HCV infected Egyptian patients treated with PEG-IFN and RBV.

METHODS

Our study was conducted on 153 chronic HCV infected patients treated with PEG-IFN and RBV. Genotyping of rs8099917 near the IL-28B gene was performed by Real Time PCR using Taq-Man probe assay.

RESULTS

The overall SVR was achieved in 49.6% of patients. Patients with TT genotype showed significantly higher SVR rate than minor allele (TG/GG) carriers (74% vs. 26%, P=0.004). Logistic regression analysis revealed that TT carriers had 2.8 higher chance for SVR achievement than G allele carriers TG/GG (OR=2.8, 95% CI=1.4-5.6, P=0.004). Younger age, male sex and low activity grading were significant predictors of SVR (P=0.003, P=<0.001 and P<0.001 respectively). High pretreatment AST levels and advanced liver fibrosis were negative predictors of SVR (P=0.04 and P<0.001 respectively).

CONCLUSION

IL28B genotype is a significant pre-treatment predictor of response to PEG-IFN/RBV in HCV infected Egyptian patients.

NS5A Sequence Heterogeneity and Mechanisms of Daclatasvir Resistance in Hepatitis C Virus Genotype 4 Infection

Background. Daclatasvir is an NS5A inhibitor approved for treatment of infection due to hepatitis C virus (HCV) genotypes (GTs) 1–4. To support daclatasvir use in HCV genotype 4 infection, we examined a diverse genotype 4–infected population for HCV genotype 4 subtype prevalence, NS5A polymorphisms at residues associated with daclatasvir resistance (positions 28, 30, 31, or 93), and their effects on daclatasvir activity in vitro and clinically.

Methods. We performed phylogenetic analysis of genotype 4 NS5A sequences from 186 clinical trial patients and 43 sequences from the European HCV database, and susceptibility analyses of NS5A polymorphisms and patient-derived NS5A sequences by using genotype 4 NS5A hybrid genotype 2a replicons.

Results. The clinical trial patients represented 14 genotype 4 subtypes; most prevalent were genotype 4a (55%) and genotype 4d (27%). Daclatasvir 50% effective concentrations for 10 patient-derived NS5A sequences representing diverse phylogenetic clusters were ≤0.080 nM. Most baseline sequences had ≥1 NS5A polymorphism at residues associated with daclatasvir resistance; however, only 3 patients (1.6%) had polymorphisms conferring ≥1000-fold daclatasvir resistance in vitro. Among 46 patients enrolled in daclatasvir trials, all 20 with baseline resistance polymorphisms achieved a sustained virologic response.

Conclusions. Circulating genotype 4 subtypes are genetically diverse. Polymorphisms conferring high-level daclatasvir resistance in vitro are uncommon before therapy, and clinical data suggest that genotype 4 subtype and baseline polymorphisms have minimal impact on responses to daclatasvir-containing regimens.

The Role of MicroRNA in Hepatitis C Virus Replication

Hepatitis C virus (HCV) infection is a major global health problem. There is no effective vaccine and the current treatment regimen with pegylated interferon α and ribavirin is associated with significant adverse events. Therefore, there is an urgent need to identify new antiviral targets for HCV therapy. In recent years, a growing number of microRNAs (miRNAs) have been reported to be able to regulate HCV replication and infection by interacting with the HCV genome directly or by regulating host innate immunity to build a nonspecific antiviral state within cells. In this review, we discuss HCV virology and standard of care followed by miRNA in general, and then give a brief overview of miRNAs involved in HCV infection and discuss their potential application as a therapeutic option for the treatment of HCV infection.

The impact of interleukin 28b gene polymorphism on the virological response to combined pegylated interferon and ribavirin therapy in chronic HCV genotype 4 infected egyptian patients using data mining analysis

BACKGROUND

Chronic HCV represents one of the common causes of chronic liver disease worldwide with Egypt having the highest prevalence, namely genotype 4. Interleukin IL-28B gene polymorphism has been shown to relate to HCV treatment response, mainly in genotype1.

OBJECTIVES

We aim to evaluate the predictive power of the rs12979860 IL28B SNP and its protein for treatment response in genotype 4 Egyptian patients by regression analysis and decision tree analysis.

PATIENTS AND METHODS

The study included 263 chronic HCV Egyptian patients receiving peg-interferon and ribavirin therapy. Patients were classified into 3 groups; non responders (83patients), relapsers (76patients) and sustained virological responders (104 patients). Serum IL 28 B was performed, DNA was extracted and analyzed by direct sequencing of the SNP rs 12979860 of IL28B gene.

RESULTS

CT, CC and TT represented 56 %, 25 % and 19% of the patients, respectively. Absence of C allele (TT genotype) was significantly correlated with the early failure of response while CC was associated with sustained virological response. The decision tree showed that baseline alpha fetoprotein (AFP ≤ 2.68 ng/ml) was the variable of initial split (the strongest predictor of response) confirmed by regression analysis. Patients with TT genotype had the highest probability of failure of response.

CONCLUSIONS

Absence of the C allele was significantly associated with failure of response. The presence of C allele was associated with a favorable outcome. AFP is a strong baseline predictor of HCV treatment response. A decision tree model is useful for predicting the probability of response to therapy.

Hepatitis C viral heterogeneity based on core gene and an attempt to design small interfering RNA against strains resistant to interferon in rawalpindi, pakistan

BACKGROUND

Global prevalence of Hepatitis C Virus (HCV) infection corresponds to about 130 million HCV positive patients worldwide. The only drug that effectively reduces viral load is interferon-α (IFN-α) and currently combination of IFN and ribavirin is the choice for treatment.

OBJECTIVES

The present study is aimed to resolve the genotypes based on core gene that might affect the response to interferon therapy. Furthermore an attempt was made to propose a powerful therapeutic approach by designing the siRNA from sequences of the same patients who remain resistant to IFN in this study.

PATIENTS AND METHODS

To achieve the objectives, a sequence analysis was performed in five HCV ELISA positive subjects who have completed IFN treatment. Neighbor Joining (NJ) method was used to study the evolutionary relationship. Atomic models were predicted using online software PROCHECK and i- TASSER.

RESULTS

Two new genotypes were reported for the first time namely 4a from suburban region of Rawalpindi and 6e from all over the Pakistan. According to Ramachandran plot, satisfactory atomic model was considered useful for further studies, i.e. to calculate HCV genotypes conservation at structural level, to find out critical binding sites for drug designing, or to silence those binding sites by using appropriate siRNA. Single siRNA can be used to inhibit HCV RNA synthesis against genotype 3 and 4, as the predicted siRNA were originated from the same domain in studied HCV core region in both genotypes.

CONCLUSIONS

We can conclude that any change or mutation in core region might be the cause of HCV strains to resist against IFN therapy. Therefore, further understanding of the complex mechanism involved in disrupting viral response to therapy would facilitate the development of more effective therapeutic regimens. Additionally, a single designed siRNA can be used as an alternative for current therapy against more than one resistant HCV genotypes.

Near-full genome characterization of unclassified hepatitis C virus strains relating to genotypes 1 and 4

Near-full genome sequences are presented in this report for the first time of unclassified HCV strains amplified using RT-PCR from plasma of patients living in Cyprus. One strain appears to be a unique genotype-1-like isolate, displaying closer phylogenetic relationship to genotype 1 strains than other genotypes. Two isolates representing an unclassified variant of genotype 4 were also amplified, cases of which have been found elsewhere in the world in patients of central African origin and could now be assigned provisionally as new subtype 4v. The near-full genome nucleotide sequences of unclassified HCV isolates provide reference sequences of variants unknown previously, and contribute to the publicly available HCV sequence data to be used for diagnosis or research.

Rising burden of Hepatitis C Virus in hemodialysis patients

Aim

High prevalence of Hepatitis C virus (HCV) has been reported among the dialysis patients throughout the world. No serious efforts were taken to investigate HCV in patients undergoing hemodialysis (HD) treatment who are at great increased risk to HCV. HCV genotypes are important in the study of epidemiology, pathogenesis and reaction to antiviral therapy. This study was performed to investigate the prevalence of active HCV infection, HCV genotypes and to assess risk factors associated with HCV genotype infection in HD patients of Khyber Pakhtunkhwa as well as comparing this prevalence data with past studies in Pakistan.

Methods

Polymerase chain reaction was performed for HCV RNA detection and genotyping in 384 HD patients. The data obtained was compared with available past studies from Pakistan.

Results

Anti HCV antibodies were observed in 112 (29.2%), of whom 90 (80.4%) were HCV RNA positive. In rest of the anti HCV negative patients, HCV RNA was detected in 16 (5.9%) patients. The dominant HCV genotypes in HCV infected HD patients were found to be 3a (n = 36), 3b (n = 20), 1a (n = 16), 2a (n = 10), 2b (n = 2), 1b (n = 4), 4a (n = 2), untypeable (n = 10) and mixed (n = 12) genotype.

Conclusion

This study suggesting that i) the prevalence of HCV does not differentiate between past and present infection and continued to be elevated ii) HD patients may be a risk for HCV due to the involvement of multiple routes of infections especially poor blood screening of transfused blood and low standard of dialysis procedures in Pakistan and iii) need to apply infection control practice.

Study of nitric oxide in patients with chronic hepatitis C genotype 4: relationship to viremia and response to antiviral therapy

Hepatitis C virus (HCV) infection is a global medical problem. The role of Nitric oxide (NO) in chronic viral hepatitis is still unknown. It may play a prominent role as an antiviral agent that reduces its replication or as a mediator that causes accumulation of oxidative DNA damage and oncogenesis. The present study was carried out to study effect of combined peginterferon and ribavirin therapy for hepatitis C on NO in both responders and in non responder patients. The study included seventy three patients with positive serological markers for HCV. They were classified according to presence or absence of HCV viremia and the response to therapy. In addition sixteen control subjects were included. NO levels were determined as the stable end product nitrate and nitrite. Serum nitrite and nitrate concentrations in the patients with viral hepatitis were significantly higher than normal subjects and patients with serological evidence of hepatitis C infection in absence of viral load. The levels of nitrite >or= 31 microM, nitrate >or= 15 microM and NO(2)/NO(3) ratio < 1.5 microM were associated with increased risk of resistance to therapy. The multivariate logistic regression analysis showed that NO(2)/NO(3) ratio at levels < 1.5 microM was associated with HCV eradication independently. This study provides new insight into the pathogenesis of hepatitis C and highlights the effect of combined peginterferon and ribavirin on nitrite and nitrate as markers of endogenous NO system. There is a limitation level of NO that if it is increased above it may lead to non response to antiviral therapy. Therefore, it may be an important factor for chronic hepatitis C, which suggests an additional therapeutic pathway of anti-oxidants in combination with the standard regimen for further study.

An overview about hepatitis C: a devastating virus

Hepatitis C (HCV) is the disease that has affected around 200 million people globally. HCV is a life threatening human pathogen, not only because of its high prevalence and worldwide burden but also because of the potentially serious complications of persistent HCV infection. Chronicity of the disease leads to cirrhosis, hepatocellular carcinoma and end-stage liver disease. HCV positive hepatocytes vary between less than 5% and up to 100%, indicating the high rate of replication of viral RNA. HCV has a very high mutational rate that enables it to escape the immune system. Viral diversity has two levels; the genotypes and Quasiaspecies. Major HCV genotypes constitute genotype 1, 2, 3, 4, 5 and 6 while more than 50 subtypes are known. All HCV genotypes have their particular patterns of geographical distribution and a slight drift in viral population has been observed in some parts of the globe.

The neglected hepatitis C virus genotypes 4, 5 and 6: an international consensus report

Abstract Hepatitis C virus (HCV) genotypes 4, 5 and 6 represent >20% of all HCV cases worldwide. HCV-4 is mainly seen in Egypt, where it represents 90% of all HCV cases. Antischistosomal therapy was the main cause of contamination there, followed by procedures performed by informal providers and traditional healers such as dental care, wound treatment, circumcision, deliveries, excision and scarification. It is also highly prevalent in sub-Saharan Africa and in the Middle East. In Europe, its prevalence has recently increased particularly among intravenous drug users and in immigrants. HCV-5 is mainly found in South Africa, where it represents 40% of all HCV genotypes, but four pockets of HCV-5 were found in France, Spain, Syria and Belgium and sporadic cases were found elsewhere. The mode of transmission is mainly iatrogenic and transfusion. HCV-6 is found in Hong Kong, Vietnam, Thailand and Myanmar and also in American and Australian from Asian origin. The response to treatment in HCV-4 is intermediate between HCV-1 and HCV-2 and HCV-3. A sustained viral response is achieved in 43-70% with pegylated interferon and ribavirin. It is higher in Egyptians than Europeans and Africans and is negatively related to insulin resistance and to the severity of fibrosis. It increases to >80% with 24 weeks of therapy only if a rapid virological response is achieved. In HCV-5, a sustained virological response is achieved in >60% with 48 weeks of therapy. HCV-6 is also considered an easy-to-treat genotype, leading to a response in 60-85% of cases.

Complete genomic sequences for hepatitis C virus subtypes 4b, 4c, 4d, 4g, 4k, 4l, 4m, 4n, 4o, 4p, 4q, 4r and 4t

In this study, we characterized the full-length genomic sequences of 13 distinct hepatitis C virus (HCV) genotype 4 isolates/subtypes: QC264/4b, QC381/4c, QC382/4d, QC193/4g, QC383/4k, QC274/4l, QC249/4m, QC97/4n, QC93/4o, QC139/4p, QC262/4q, QC384/4r and QC155/4t. These were amplified, using RT-PCR, from the sera of patients now residing in Canada, 11 of which were African immigrants. The resulting genomes varied between 9421 and 9475 nt in length and each contains a single ORF of 9018-9069 nt. The sequences showed nucleotide similarities of 77.3-84.3 % in comparison with subtypes 4a (GenBank accession no. Y11604) and 4f (EF589160) and 70.6-72.8 % in comparison with genotype 1 (M62321/1a, M58335/1b, D14853/1c, and 1?/AJ851228) reference sequences. These similarities were often higher than those currently defined by HCV classification criteria for subtype (75.0-80.0 %) and genotype (67.0-70.0 %) division, respectively. Further analyses of the complete and partial E1 and partial NS5B sequences confirmed these 13 'provisionally assigned subtypes'.

Response to pegylated interferon plus ribavirin in HIV-infected patients with chronic hepatitis C due to genotype 4

Hepatitis C virus (HCV) genotypes 1 and 4 respond less well to pegylated interferon (pegIFN) plus ribavirin (RBV) therapy. For this reason most studies merge these two genotypes when assessing virological response. However, in most trials the HCV genotype 4 population is rather small, and conclusions are mainly derived from what occurs in HCV-1 patients. All HCV-4 patients coinfected with HIV who received pegIFN plus RBV in two different multicentre studies, PRESCO and ROMANCE, conducted respectively in Spain and Italy, were retrospectively analyzed. Baseline plasma HCV-RNA, proportion of patients with HCV-RNA <10 IU / mL at week 4 (rapid virological response), and HCV-RNA declines >2 logs at week 12 (early virological response, EVR) were all assessed as predictors of sustained virological response (SVR). Overall, 75 patients (60 men) were evaluated. Median age was 40 years and median CD4 count 598 cells / mm(3); 49% had plasma HIV-RNA <50 copies / mL; 71% had elevated liver enzymes and 31% had advanced liver fibrosis (Metavir F3-F4). Median serum HCV-RNA was 5.7 log IU / mL. Rapid virological response was attained by 10 (20%) patients and EVR by 26 (42%). Using intention-to-treat and on-treatment (OT) analyses, SVR was achieved by 21 / 75 (28%) and 21 / 62 (34%) of HCV-4 patients, respectively. In the multivariate analysis (OT), baseline HCV-RNA (OR 0.09 for every log increment; 95% CI: 0.01-0.7) and EVR (OR: 7.08; 95% CI: 1.8-27.2) were significantly and independently associated with SVR. This is the largest series of HIV-infected patients with chronic hepatitis C due to HCV-4 treated with pegIFN plus RBV examined so far and the results show that HCV-4 behaves similarly to HCV-1. Therefore, these patients should be considered as difficult to treat population. Baseline serum HCV-RNA and EVR are the best predictors of SVR in HCV-4 / HIV-coinfected patients.

Frequency distribution of hepatitis C virus genotypes in different geographical regions of Pakistan and their possible routes of transmission

Background

Information regarding hepatitis C virus genotypes and subtypes circulating in Pakistan and various risk factors for their transmission are not known well. The specific objective of this study was to find out the frequency of various HCV genotypes present in well-characterized Pakistani HCV isolates and their possible routes of transmission.

Methods

A total of 3351 serum samples were tested by type-specific genotyping assay. Out of 3351 HCV RNA positive patients, 2039 were males and 1312 were females. As regard as genotyped samples, 2165 belonged to Punjab region, 823 belonged to N.W.F.P., 239 to Sindh and 124 patients were from Balochistan.

Results

Out of the total 3351 tested serum samples, type-specific PCR fragments were observed in 3150 (94.00%) serum samples. The distribution of genotypes of the typeable samples as determined by this assay, was as follows: 1664 (49.05%) genotype 3a; 592 (17.66%) genotype 3b; 280 (8.35%) genotype 1a; 252 (7.52%) genotype 2a; 101 (3.01%) genotype 1b; 50 (1.49%) with genotype 4; 25 (0.75%) with 3c; 27 (0.80%) genotype 2b; 6 (0.18%) with subtype 5a; 5 (0.15%) genotype 1c; 4 (0.12%) with subtype 6a; 3 (0.09%) genotype 2c; and 161 (4.80%) patients were infected with mixed infection. Two hundred and one (5.99%) serum samples were found untypeable by the present genotyping system. More than 86% and 72% patients with genotypes 3a and 3b respectively had received multiple injections in past. For genotypes 1a and 1b the route of transmission was major/minor surgery along with unknown reasons. Majority of the cases with type 2a, 2b and indeterminate genotypes were sporadic. Mixed infections were common in thalassaemic patients.

Conclusion

The most common HCV genotype in Pakistan is type 3a. Regional difference in genotypes was observed only in Balochistan province of Pakistan. More than 70% of the cases were acquired in hospitals through reuse of needles/syringes and major/minor surgery that is very common in this country.

Very Early Viral Kinetics on Interferon Treatment in Chronic Hepatitis C virus Genotype 4 Infection

Background

Interferon (IFN)-resistant hepatitis C virus strains limit efficacy of antiviral combination therapy in patients infected with genotypes 1 and 4. A single test dose of IFN was useful to identify non-responders to IFN-α2b/ribavirin (RBV) or likely non-responders to pegylated (PEG)-IFN-α2a/RBV therapy in genotype 1 patients. Our aim was to investigate this approach in genotype 4 patients.

Methods

Viral load was measured in 46 patients before and 24 h after 10 megaunits (MU) IFN-α2b, and before and during 2 weeks of daily 5 MU IFN-α2b administration. Thereafter, patients received 48 weeks combination therapy with either 180 μg PEG-IFN-α2a/week ( n=33), 1.5 μg/kg PEG-IFN-α2b/week ( n=7) or 5 MU IFN-α2b/2 days ( n=6), along with 1–1.2g RBV/day. For prediction analysis the largest group (PEG-IFN-α2a) was evaluated only.

Results

Median 24 h log10 change after 10 MU IFN-α2b was 1.15 (range 0.08–2.48) and after 5 MU IFN-α2b was 0.81 (-0.12–2.22; P<0.0001). Log10 changes after 2 weeks on 5 MU IFN-α2b daily and 24 h after 10 MU were the best predictors of early virological response (defined by negativity of a standard qualitative PCR) to PEG-IFN-α2a/RBV combination therapy (area under curve [AUC]=0.97; P<0.001, receiver operating characteristics), 24 h log10 change after 10 MU was the best predictor of sustained virological response (SVR; AUC=0.91, P=0.001).

Conclusion

As in genotype 1 patients, there is large variation in IFN responsiveness, including the presence of resistant strains, in genotype 4 patients. A 24 h log10 change after 10 MU IFN-α2b is an excellent predictor of SVR on PEG-IFNα2a/RBV combination therapy. This test may be useful to obtain homogeneous groups for clinical studies and could help in clinical decision making.

Hepatitis C genotype 4: What we know and what we don't yet know

Hepatitis C virus genotype 4 (HCV-4) is the most common variant of the hepatitis C virus (HCV) in the Middle East and Africa, particularly Egypt. This region has the highest prevelance of HCV worldwide, with more than 90% of infections due to genotype 4. HCV-4 has recently spread in several Western countries, particularly in Europe, due to variations in population structure, immigration, and routes of transmission. The features of HCV-4 infection and the appropriate therapeutic regimen have not been well characterized. This review discusses the virology, epidemiology, natural history, histology, clinical data, and treatment options for patients with HCV-4 infections. Early reports on the treatment of patients with chronic HCV-4 with conventional interferon (IFN)-alpha monotherapy indicated poor rates of sustained viral response (SVR), which improved slightly when combined with ribavirin. Pegylated IFN and ribavirin combination therapy has dramatically improved the response rates, with recent clinical trials showing rates that exceed 60%. These data can now be used as a platform for further research to define optimal treatment duration and predictors of SVR in patients with HCV-4 infection.

CONCLUSION

HCV-4 infection is spreading beyond its strongholds in Africa and the Middle East. Recent clinical trials show that HCV-4 is not difficult to treat, as the response to treatment may be at an intermediate level compared with genotype 1 and genotypes 2 or 3. Tailored treatment options that are comparable to the treatment approaches for genotype 1, 2, and 3 patients to optimize treatment for each patient are now being developed.

Pegylated interferon alpha-2b plus ribavirin in patients with genotype 4 chronic hepatitis C: The role of rapid and early virologic response

In patients chronically infected with hepatitis C virus (HCV) genotype 4, the optimum duration of therapy and the predictors of sustained virologic response (SVR) have not been adequately determined. In this study, 358 patients with chronic hepatitis C genotype 4 were randomly assigned to pegylated interferon (PEG-IFN) alpha-2b (1.5 mug/kg/week) plus oral ribavirin (10.6 mg/kg/day) for a fixed duration of 48 weeks (control group, n = 50) or for a variable duration (n = 318). In the variable-duration group, patients with undetectable HCV RNA at week 4 were treated for 24 weeks (group A, n = 69), patients with undetectable HCV RNA at week 12 were treated for 36 weeks (group B, n = 79), and the rest of the patients were treated for 48 weeks (group C, n = 160). The primary endpoint was SVR (undetectable HCV RNA 24 weeks after treatment cessation). Groups A-C and the control group had SVR rates of 86%, 76%, 56%, and 58%, respectively. After the study was controlled for predictors, a low baseline histologic grade and stage were associated with SVR (P < 0.029) in all groups. In addition, among patients in group C, older age (P = 0.04), a higher baseline body mass index (P = 0.013), and low baseline HCV RNA (P < 0.001) were also associated with SVR attainment. The incidence of adverse events and the rate of discontinuation were higher in patients in the variable-duration and fixed-duration groups treated for 48 weeks.

CONCLUSION

In patients with chronic hepatitis C genotype 4 and undetectable HCV RNA at weeks 4 and 12, treatment with PEG-IFN alpha-2b and ribavirin for 24 weeks and 36 weeks, respectively, is sufficient.

Improving outcome in patients with hepatitis C virus genotype 4

Several factors influence treatment outcomes among patients with chronic hepatitis C. A trend is growing to adapt an individualized treatment approach to optimize treatment outcomes among chronic hepatitis C patients. Hepatitis C virus (HCV) genotype is an important factor that determines treatment outcomes among patients with chronic hepatitis C. HCV has six genotypes, and genotype 4 (G4) accounts for 20% of all global HCV infections. Patients with G4 are underrepresented in clinical trials involving patients with chronic hepatitis C because most patients infected with G4 are in Egypt, Africa, and Middle Eastern countries. Therefore, there is little information about the predictors of response to standard treatment among chronic hepatitis C patients with HCV G4. Initial evidence suggested that patients with G4 HCV are as difficult to treat as patients with G1; however, recent evidence suggests that the response rates to treatment among patients with G4 may be better than those with G1 but not those with G2 or G3. This review discusses the clinical data among patients with G4 and assesses the impact of an individualized approach on improved treatment outcomes in these patients.

Clinical and pathological characteristics and response to combination therapy of genotype 4 chronic hepatitis C patients: experience from a spanish center

This observational study evaluated the characteristics of genotype 4 chronic hepatitis C (CHC) patients and their response to combination therapy in Spain. 383 patients with CHC, 44 with genotype 4-HCV infection, were investigated. Nineteen genotype 4-HCV infected patients received IFNalpha-2b (3 MU three times weekly) plus ribavirin (1-1.2 g/day) and ten received Peg-IFNalpha-2b (1.5 microg/kg/week) plus ribavirin (1-1.2 g/day) for 12 months. A sustained virological response (SVR) was evaluated. Genotype 4-HCV was detected in 11.5% of patients, and was significantly associated with a higher proportion of infection through intravenous drug use (46% vs 11%; p<0.001), a higher alcohol intake (35% vs. 7%; p<0.001), higher proportion of anti-HBc positivity (41% vs. 22%; p<0.05), lower ALT (87+/-50 vs. 139+/-142 IU/L; p<0.001) and AST (53+/-30 vs. 85+/-126 IU/L; p<0.001) levels, lower viremia (4.1 +/- 7.7 (x 10(5)) vs . 7.3 +/- 9.8 IU(x 10(5) )/mL) p<0.05) and less fibrosis (stage 3-4 in 21% vs. 32%; p<0.06). Sixteen (55%) out of the 29 patients treated with combination therapy achieved a sustained virological response (SVR) while 10 (36%) were non-responders and 3 (9% relapsed. In conclusion, the lower stage of fibrosis, lower viremia and higher SVR rate than genotype 1 suggest a less aggressive pattern of diseased caused by this genotype.

Epidemiological characteristics and response to peginterferon plus ribavirin treatment of hepatitis C virus genotype 4 infection

Hepatitis C virus genotype 4 (HCV-4) infection is progressing in Europe, where epidemiology and sustained virological response (SVR) seem to be different than in the Middle East. We analysed epidemiological features and SVR rates in a retrospective study of 1532 HCV-4-infected patients, including 1056 patients infected in France, 227 immigrants infected in Egypt and 249 in sub-Saharan Africa. SVR rates were assessed in 242 naive patients of the 1532, who received peginterferon plus ribavirin for 48 weeks. HCV subtype 4a or 4d was the most common among patients infected in France, where the predominant route of transmission was intravenous drug abuse. The 4a subtype was largely predominant (93%) among patients infected in Egypt, where transmission was mostly because of parenteral treatment for schistosomiasis. More than seven different subtypes and no predominant route of infection were found in patients infected in sub-Saharan Africa. Liver fibrosis was significantly less severe in patients infected in France and Africa than in patients infected in Egypt. SVR rates were higher in patients infected in Egypt, compared with those infected in France or Africa (54.9%, 40.3% and 32.4%, respectively, P < 0.05). An overall better response was observed in patients infected with the 4a subtype. In multivariate analysis, two factors were associated independently with SVR: the Egyptian origin of transmission and the absence of severe fibrosis. In conclusion, the distribution of HCV-4 subtypes varies with the geographical origin of transmission and affects the SVR following antiviral treatment.

Treatment of hepatitis C virus genotype 4 with peginterferon alfa-2a: Impact of bilharziasis and fibrosis stage

AIM: To evaluate pegylated interferon alpha2a (PegIFN-α2a) in Egyptian patients with HCV genotype 4, and the impact of pretreatment viral load, co-existent bilharziasis and histological liver changes on response rate.

METHODS: A total of 73 naïve patients (61 with history of bilharziasis) with compensated chronic HCV genotype 4 were enrolled into: group A (38 patients) who received 180 mg PegIFN-alpha2a subcutaneously once weekly for a year and group B (35 patients) received IFN alpha-2a 3 MU 3 times weekly. Ribavirin was added to each regimen at a dose of 1200 mg. Patients were followed for 72 wk and sustained response was assessed.

RESULTS: Significant improvement in both end of treatment response (ETR) (P < 0.002) and sustained response (SR) (P < 0.05) was noted with pegylated interferon, where ETR was achieved in 29 (76.3%) and 14 patients (40%) in both groups respectively, and 25 patients in group A (65.8%) and 9 (25.7%) in group B could retain negative viraemia by the end of follow up period. Sustained virological response (SVR) showed a significant negative correlation with age and positive correlation with pretreatment inflammation in patients receiving PegIFN. Viral clearance after 3 mo of therapy was associated with high incidence of ETR and SR (P < 0.001), but without significant difference between both forms of interferon. Significant improvement in response was achieved in patients with high grade fibrosis (grade 3 and 4) with PegIFN-α2a, where SR was seen in 5 out of 13 patients in group A, but none in group B. There was no significant difference in response between bilharzial and non-bilharzial patients in both groups. In terms of safety and tolerability, neutropenia was the predominant side effect; both drugs were comparable.

CONCLUSION: PegIFN-α2a combined with ribavirin results in improvement in sustained response in HCV genotype 4, irrespective of history of bilharzial infestation.

HCV genotype 4 in Belgium: three distinct patterns among patients from European and African origin

BACKGROUND

Considered uncommon in western countries some years ago, hepatitis C virus of genotype 4 is now spreading in some areas of Europe. This is assumed to be due to immigration from a region of high prevalence for this genotype and to propagation among drug users. In the south of Belgium, genotype 4 currently accounts for 10% of hepatitis C virus patients and its prevalence is increasing with time.

OBJECTIVE

To better define the genotype 4 carriers' characteristics.

METHODS

In a database comprising 1726 viraemic hepatitis C virus patients, the files of 85 genotype 4 carriers were reviewed.

RESULTS

Beside the African (58%) and European drug user (15%) subgroups classically described, a third subgroup consisting of European nondrug users (26%) was identified as peculiar: these patients were older, had been mostly contaminated sporadically, presented a great diversity of subtypes, and were mainly of Italian origin. In this subgroup, contamination was supposed to be ancient, having occurred probably in Italy before immigration into Belgium. By contrast, European drug users were infected with only two subtypes (4c/4d and 4), an observation in favour of recent spread. Africans had a great diversity of subtypes, were young, and were mostly contaminated sporadically in their home countries. Despite their epidemiological differences, the clinical management, and in particular the rates of eligibility for treatment, were similar for these three groups.

CONCLUSIONS

Three different patterns of genotype 4 carriers were observed, corresponding to three different spreading profiles. They did not induce, however, different clinical management.

Distribution of hepatitis C virus genotypes in the Middle East

It is well established that hepatitis C develops into cirrhosis of the liver and hepatocellular carcinoma (HCC) both of which are fatal diseases. The World Health Organization estimates that there are at least 21.3 million hepatitis C virus (HCV) carriers in the Eastern Mediterranean countries, which is close to the number of carriers estimated in the Americas and Europe combined. With such a high disease burden of HCV infection in this part of the world, and in light of the new evidence that genotypes may influence the outcome of antiviral therapy, the focus of this review is on the epidemiology and distribution of HCV genotypes in the Eastern Mediterranean countries. Accumulated data show that there are two main patterns for the distribution of HCV genotypes in the Middle East: in the first pattern, genotype 4 is prevalent in most of the Arab countries, and in the second pattern, genotype 1a or 1b predominates in the non-Arab countries. Results from the limited number of clinical trials on the treatment of chronic HCV genotype 4 using peginterferon alfa-2b in combination with ribavirin are encouraging. However, efforts to develop more effective antiviral therapies and the establishment of an effective HCV vaccine remain the largest challenges for the near future.

Follow-up of the prevalence of hepatitis C virus genotypes in Spain during a nine-year period (1996-2004)

BACKGROUND

Recent data suggest that the prevalence of genotype 4 HCV strains among Spanish carriers is increasing.

OBJECTIVE

To assess changes in the prevalence of HCV genotypes in Spain during the last nine years.

METHODS

HCV RNA was amplified by the polymerase chain reaction from 3161 serum samples from unselected, anti-HCV-positive individuals, and the HCV genotype was identified by a reverse hybridisation assay (line probe assay, LiPA). Samples came from 17 different regions of Spain and were obtained between January, 1996 and December, 2004.

RESULTS

The overall prevalence of HCV genotypes was: 1b, 41.3%; 1a, 24.1%; 3, 19.6%; 4, 11.6%; 2, 3.1%; and 5, 0.3%. The prevalence of genotypes 1a, 3 and 4 increased significantly among patients born after 1950, and that of genotype 1b decreased among them. These significant differences in regard to age were also observed among patients lacking notified high-risk factors. A main switch-up in prevalence of genotypes 1a and 3 was found when patients born in 1941-1950 were compared with those born in 1951-1960, but the same finding in genotype 4 was delayed to patients born in 1961-1970.

CONCLUSIONS

Two separate epidemics of HCV seem to have occurred in Spain during the last 30 years. The former one involved the spread of HCV genotypes 1a and 3. The second was more recent, and involved the spread of genotype 4.

Changes in epidemiological patterns of HCV infection and their impact on liver disease over the last 20 years in Greece

The aim of this study was to investigate the relative frequency of hepatitis C virus (HCV) genotypes in Greek patients with chronic infection as well as possible secular changes in their distribution in relation to modes of transmission, age and time at acquisition of the infection and other variables. We evaluated 434 unselected patients, 241 males and 193 females with a median age of 46.2 years (18-75), with chronic HCV infection presenting during the period 1996-2000. HCV infection was confirmed by the detection of HCV-RNA by polymerase chain reaction (PCR), while HCV genotyping was performed by the Inno-LiPA assay. Liver biopsies were evaluated according to Ishak's scoring system. Of 434 patients, 167 had a history of blood transfusion [post-transfusion hepatitis (PTH)], 80 were i.v. drug users and in 187 the route of infection remained unknown. The overall distribution of HCV genotypes 1, 2, 3 and 4 was 47, 8.3, 27 and 15.2%, respectively. Genotype 3 was common in younger adults and i.v. drug users, whereas genotype 1 predominated in older people and PTH patients (P < 0.001 for both). Infection acquired before 1981 (group A) was related to transfusion and genotype 1, while after 1981 (group B) with i.v. drug use and genotype 3 (P < 0.01). Biopsy was available in 369 (85%) patients, of whom 22.5% had cirrhosis; 29.8% in group A and 9.9% in group B. In a multivariate analysis, cirrhosis was strongly associated with the duration of infection (P = 0.013). Our study revealed a change of HCV genotype distribution in the last 20 years among Greek patients with chronic HCV infection as a result of epidemiological changes in HCV transmission. The presence of cirrhosis was associated only with the duration of infection. These observations have impact both on prevention and treatment.

Chronic hepatitis C: genotypes 4 to 9

Infection with hepatitis C virus (HCV) genotypes 1, 2, or 3 is widely distributed throughout the world and has been the focus of the majority of studies on the epidemiology and treatment of chronic hepatitis C. Infection with HCV genotypes 4 through 9 is prevalent in some geographic areas where the disease burden of chronic hepatitis C approaches endemic levels (eg, HCV genotype 4 in Egypt where there is an HCV infection prevalence of approximately 18%). This article reviews the existing literature, which suggests that chronic hepatitis C with genotypes 4 through 9 may exhibit epidemiologic, clinical, and treatment outcome differences from infection with genotypes 1, 2, or 3.

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.