Hepatitis C virus genotypes: epidemiological and clinical associations. Benelux Study Group on Treatment of Chronic Hepatitis C

Esthetic and medical tattooing: Part I: Tattooing techniques, implications, and adverse effects in healthy populations and special groups

Tattooing, the introduction of exogenous pigments into the skin, has a rich history spanning thousands of years, with cultural, cosmetic, and medical significance. With the increasing prevalence of tattoos, understanding their potential complications and contraindications is of growing importance. The most common complications are hypersensitivity reactions, which may vary in morphology and timing. Infectious complications are often due to inadequate aseptic and hygienic practices during the tattooing process or healing period. Tattoo pigment can present diagnostic challenges, affecting cancer diagnosis and imaging. This CME article explores the history, cultural significance, epidemiology, chemistry, technique, contraindications, and complications of tattoos. Appreciating these factors can help individuals considering tattoos understand the safety and potential risks of their body art, and provide physicians with a thorough understanding of tattooing if consulted.

Prevalence, determinants and genetic diversity of hepatitis C virus in the multi-ethnic population living in Suriname

Little is known about the epidemiology of HCV in Suriname, a former Dutch colony in South America. To study the prevalence, determinants and genetic diversity of HCV, a one-month survey was conducted at the only Emergency Department in the capital Paramaribo. Participants (≥18 years) completed an interviewer-led standardized HCV risk-factor questionnaire, were tested for HCV-antibodies, and if positive also for HCV RNA. The overall HCV prevalence was 1.0% (22/2128 participants; 95%CI 0.7-1.5). Male sex (OR=4.11; 95%CI 1.30-13.01), older age (OR=1.06 per year increase; 95%CI 1.04-1.09), Javanese ethnicity (OR=7.84; 95%CI 3.25-18.89) and cosmetic tattooing (OR=31.7; 95%CI 3.25-323.87) were independently associated with HCV-infection. Phylogenetic analysis revealed six distinct HCV subtypes, all HCV-genotype 2 (HCV-2): subtype 2f (also circulating in Indonesia) plus five yet unassigned HCV-2 subtypes exclusively linked to Suriname.

Resource use and cost of hepatitis C-related care

BACKGROUND

Chronic hepatitis because of the hepatitis C virus (CHC) is a major health problem that can lead to decompensated cirrhosis, hepatocellular carcinoma, and eventually death, all of which are associated with significant healthcare costs.

AIM

To update the cost of care of CHC according to the different severity stages of the disease in a west European country (Belgium).

METHODS

Medical records of 157 patients, who were referred to the medical specialist at different stages of disease, were reviewed to identify the medical costs over a follow-up period of 3 years or 2 years in the case of liver transplantation (LT). Six disease stages were defined on the basis of histology (Metavir classification) and/or clinical data.

RESULTS

In comparison with mild disease, the cost increased 1.6 times in the case of decompensated cirrhosis, 1.9 times in the case of hepatocellular carcinoma, and 3.4 in the case of LT. The costs for medication, hospitalization, and ambulatory care were, respectively, on the one hand, 81, 8, and 11% for mild disease and, on the other, 18, 79, and 3% for LT. In the case of a sustained viral response, the cost of follow-up within 3 years decreased by 45% for patients with mild and moderate disease.

CONCLUSION

Antiviral treatment is the most important factor governing cost in mild and moderate disease, but once complications of CHC occur, hospitalization costs far exceed the cost of antiviral therapy. Already during the first 3 years of follow-up, sustained viral response decreased the cost significantly. Treatment of patients with CHC in an early stage has the potential to be cost-effective.

Mutations in two PKR-binding domains in chronic hepatitis C of genotype 3a and correlation with viral loads and interferon responsiveness

Interferon (IFN) induces the double-stranded RNA-dependent protein kinase (PKR) to inhibit viral replication. Two motifs of the PKR-binding domain exist in the E2 and the NS5A regions of the hepatitis C virus (HCV). These regions are called the PKR-eukaryotic transcription factor (elF2-alpha) phosphorylation homology domain (PePHD), and the IFN sensitivity-determining region (ISDR). Both regions are inhibited by PKR. Thus, several studies have reported the relationship between these regions and IFN responsiveness and the HCV viral load. However, the data obtained from these studies remain controversial. The aim of this study was to investigate the genomic heterogeneity of the PePHD and the ISDR in patients with genotype 3a and how this impacts HCV replication and the response to IFN therapy. Twenty-one male patients infected with HCV genotype 3a were studied. The PePHD was well conserved, and mutations were found in only one amino acid position in two patients. Patients with three or more mutations in the ISDR had lower viral loads than those with fewer than two mutations (192.2 ± 176.7 vs. 1279.4 ± 997.6 KIU/ml, P = 0.0277). Ten (71.4%) of 14 patients achieved a sustained virological response to IFN therapy. No specific amino acid substitutions in the PePHD and the ISDR were associated with IFN responsiveness; however, the number of mutations in the ISDR was significantly associated with the HCV viral load. The findings from this study suggest that the ISDR plays an important role in regulating viral replication in patients infected with HCV genotype 3a.

Efficacy of interferon-based antiviral therapy in patients with chronic hepatitis C infected with genotype 5: a meta-analysis of two large prospective clinical trials

The characteristics and response rate to pegylated interferon and ribavirin (PEG-INF + RBV) of patients with chronic hepatitis C infected with genotype 5 are poorly documented. A meta-analysis of two large phase III/IV prospective randomized clinical trials conducted in Belgium in patients with chronic hepatitis C (n = 1,073 patients) was performed in order to compare the response to antiviral therapy of hepatitis C virus (HCV) genotype 5 with that of other HCV genotypes. A subset of HCV-1 infected patients selected from within the study database were selected to match the HCV-5 sample for known prognostic factors. In Belgium HCV-5 is responsible for a significant minority of cases of chronic hepatitis C CHC (4.5%) and is characterized by a more advanced age (58.4 years), a high frequency of cirrhosis (27.7%), a specific mode of HCV acquisition, and a particular geographic origin (66.7% of patients from West Flanders). The primary comparative analysis showed that response to treatment with PEG-INF + RBV of HCV-5 is similar to HCV-1 and lower compared to HCV-2/3. The analysis of the matched patient subgroup demonstrates that the HCV-5 "intrinsic sensitivity" to PEG-IFN + RBV therapy is identical to HCV-1, with a sustained virological response of 55% in both groups. In contrast to previous publications, this meta-analysis suggests that HCV-5 response to treatment is closer to HCV-1 than to HCV-2/3 and suggests that in Belgium HCV-5 infection should be treated with the same antiviral regimen as HCV-1.

Hepatitis C virus infection among drug injectors in St Petersburg, Russia: social and molecular epidemiology of an endemic infection

AIMS

To understand the epidemiology and transmission patterns of hepatitis C virus (HCV), the predominant blood borne-pathogen infecting injection drug users (IDUs), in a part of the former Soviet Union.

DESIGN

Cross-sectional respondent-driven sample of IDUs.

SETTING

St Petersburg, Russia.

PARTICIPANTS

A total of 387 IDUs were recruited in late 2005 and throughout 2006.

MEASUREMENTS

Participants were surveyed to collect demographic, medical and both general and dyad-specific drug injection and sexual behaviors. A blood sample was collected to detect antibodies to hepatitis C and to amplify viral RNA for molecular analysis. The molecular data, including genotypes, were analyzed spatially and linkage patterns were compared to the social linkages obtained by respondent-driven sampling (RDS) for chains of respondents and among the injection dyads.

FINDINGS

HCV infection was all but ubiquitous: 94.6% of IDUs were HCV-seropositive. Among the 209 viral sequences amplified, genotype 3a predominated (n = 119, 56.9%), followed by 1b (n = 61, 29.2%) and 1a (n = 25, 11.9%). There was no significant clustering of genotypes spatially. Neither genotypes nor closely related sequences were clustered within RDS chains. Analysis of HCV sequences from dyads failed to find associations of genotype or sequence homology within pairs.

CONCLUSIONS

Genotyping reveals that there have been at least five unique introductions of HCV genotypes into the IDU community in St Petersburg. Analysis of prevalent infections does not appear to correlate with the social networks of IDUs, suggesting that simple approaches to link these networks to prevalent infections, rather than incident transmission, will not prove meaningful. On a more positive note, the majority of IDUs are infected with 3a genotype that is associated with sustained virological response to antiviral therapy.

Diagnosis and clinical impact of occult hepatitis B infection in patients with biopsy proven chronic hepatitis C: a multicenter study

Occult hepatitis B virus (HBV) infection in patients with chronic hepatitis C has been found associated with severe liver damage, low response to interferon treatment and increased risk of developing HCC. However, doubts remain on its clinical impact and the sensitivity and specificity of its detection. HBV-DNA was sought by PCR in plasma, peripheral blood mononuclear cells (PBMCs) and liver compartments of 89 patients with biopsy proven chronic hepatitis C, using sets of primers for core ("c"), surface ("s"), and x ("x") regions of HBV genome. Occult HBV infection was defined by the presence of HBV-DNA in at least two different PCRs in at least one compartment. Occult HBV infection was detected in 37 (41.6%) of the 89 patients investigated. It was more frequent (80.8%) in 26 anti- HBs negative/anti-HBc positive patients than in 18 anti-HBs/anti-HBc positive (61.1%, P < 0.01) and 45 anti-HBs/anti-HBc negative (11.1%, P < 0.0001), and more frequently in liver (91.9%) than in PBMCs (62.2%) and plasma (32.4%). No association was found between occult HBV infection and the degree of liver necroinflammation and fibrosis. However, considering the 52 patients without occult HBV infection, 51.4% of 35 patients with genotype 1 and 5.9% of 17 with genotype non-1 showed severe fibrosis (P = 0.003); patients with occult HBV infection did not show such difference. Instead of seeking occult HBV infection in patients with chronic hepatitis C, both anti-HBs negative/anti-HBc positive and anti-HBs positive/anti-HBc positive, in plasma alone, more reliable information can also be obtained from the liver tissue and PBMCs.

Hepatitis C virus genotypes distribution and transmission risk factors in Luxembourg from 1991 to 2006

AIM: To analyze the Hepatitis C virus (HCV) genotype distribution and transmission risk factors in a population of unselected patients in Luxembourg.

METHODS: Epidemiological information (gender, age and transmission risks) were collected from 802 patients newly diagnosed for hepatitis C and living in Luxembourg, among whom 228 patients referred from prison. Genotyping using 5’noncoding (5’NC) sequencing was performed. We compared categorical data using the Fisher’s exact F-test and odds ratios (OR) were calculated for evaluating association of HCV genotype and risk factors.

RESULTS: The sex ratio was predominantly male (2.2) and individuals aged less than 40 years represented 49.6% of the population. Genotype 1 was predominant (53.4%) followed by genotype 3 (33%). Among risk factors, intravenous drug usage (IVDU) was the most frequently reported (71.4%) followed by medical-related transmission (17.6%) including haemophilia, transfusion recipients and other nosocomial reasons. Genotype 3 was significantly associated to IVDU (OR = 4.84, P < 0.0001) whereas genotype 1 was significantly associated with a medical procedure (OR = 2.42, P < 0.001). The HCV genotype distribution from inmate patients differed significantly from the rest of the population (Chi-square test with four degrees of freedom, P < 0.0001) with a higher frequency of genotype 3 (46.5% vs 27.5%) and a lower frequency of genotype 1 and 4 (44.7% vs 56.8% and 5.3% vs 9.6%, respectively). IVDU was nearly exclusively reported as a risk factor in prison.

CONCLUSION: We report the first description of the HCV genotype distribution in Luxembourg. The repartition is similar to other European countries, with one of the highest European prevalence rates of genotype 3 (33%). Since serology screening became available in 1991, IVDU remains the most common way of HCV transmission in Luxembourg.

Tattoos: dermatological complications

From the Eskimo in Greenland to the tribes in Polynesia-the whole world knows the art of tattoo. Despite their wide popularity the relation between the skin diseases and the tattooed pictures aren't studied in depth. With the appearance of professional tattoo studios, the risk of infectious complications was reduced. Simultaneously, on a global scale there has been an increase in pseudolymphoma and allergic reactions caused by the introduction of an exogenous pigment into the dermis. The results of our clinical and therapeutic research and review of literature on the subject outline the major problems related to tattoos, i.e. clinical complications. The summarized data showed infectious diseases transmitted through the process of tattooing and many allergic reactions, granulomas and tumors as complications of a tattoo.

Does the clinical outcome of hepatitis C infection vary with the infecting hepatitis C virus type?

Whether differences in the natural history of hepatitis C virus (HCV) can be explained by differences in the infecting HCV type is unknown. The aim of this study was to investigate whether the HCV type might influence the clinical outcome of infection. Study serum samples were assembled from 749 individuals enrolled into the UK HCV National Register from which data on clinical outcomes were extracted. HCV-RNA-positive specimens were genotyped and HCV-RNA-negative specimens serotyped. Logistic regression analysis was used to investigate the independent effect of HCV type on viral clearance by comparing patients who were HCV RNA negative (n = 86) with those who were HCV RNA positive (n = 508). The same method was used to investigate whether HCV type was associated with histological stage of liver disease. The prevalence of HCV type 1 among those who cleared infection was 69% and among those who remained HCV RNA positive was 51%: Type 1 infections were more likely to be HCV RNA negative than non-1 types (OR 0.47, 95% CI 0.29-0.78, P = 0.003). Type 1 infections were also more likely to be associated with histological stage scores above the median when compared with non-1 types (OR 2.03, 95% CI 1.07-3.83, P = 0.03). In conclusion, HCV type 1 infection was more often HCV RNA negative, suggesting that spontaneous clearance may occur more commonly with this type. Among the RNA-positive infections, type 1 infection may be more aggressive than types 2/3.

Hepatitis C virus genotypes in Serbia and Montenegro: The prevalence and clinical significance

AIM: To investigate the prevalence of hepatitis C virus (HCV) genotypes in Serbia and Montenegro and their influence on some clinical characteristics in patients with chronic HCV infection.

METHODS: A total of 164 patients was investigated. Complete history, route of infection, assessment of alcohol consumption, an abdominal ultrasound, standard biochemical tests and liver biopsy were done. Gene sequencing of 5’ NTR type-specific PCR or commercial kits was performed for HCV genotyping and subtyping. The SPSS for Windows (version 10.0) was used for univariate regression analysis with further multivariate analysis.

RESULTS: The genotypes 1, 2, 3, 4, 1b3a and 1b4 were present in 57.9%, 3.7%, 23.2%, 6.7%, 6.7% and 1.8% of the patients, respectively. The genotype 1 (mainly the subtype 1b) was found to be independent of age in subjects older than 40 years, high viral load, more severe necro-inflammatory activity, advanced stage of fibrosis, and absence of intravenous drug abuse. The genotype 3a was associated with intravenous drug abuse and the age below 40. Multivariate analysis demonstrated age over 40 and intravenous drug abuse as the positive predictive factors for the genotypes 1b and 3a, respectively.

CONCLUSION: In Serbia and Montenegro, the genotypes 1b and 3a predominate in patients with chronic HCV infection. The subtype 1b is characteristic of older patients, while the genotype 3a is common in drug abusers. Association of the subtype 1b with advanced liver disease, higher viral load and histological activity suggests earlier infection with this genotype and eventually its increased pathogenicity.

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

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

Molecular epidemiology of hepatitis C among drug users in Flanders, Belgium: association of genotype with clinical parameters and with sex- and drug-related risk behaviours

The aim of this study was to determine the genotypic variation of hepatitis C among drug users in Flanders and to relate the distribution of genotypes to the characteristics of the population. Hepatitis C virus RNA (HCV-RNA) quantification and genotyping was performed on stored samples from 161 anti-HCV-positive injecting and non-injecting drug users. Information on sociodemographic status, drug-related risk behaviour and sexual risk behaviour was available for each drug user. HCV-RNA was present in 152 of 161 samples (94.4%). Genotype 1 was predominant (48.7%), followed by genotype 3 (41.2%), genotype 4 (8.8%) and genotype 2 (1.4%). In the multivariate analysis, lack of a history of injecting drug use was confirmed as a statistically significant predictor for infection with genotype 1. Predictors for infection with genotype 3 were the presence of anti-HBc antibodies and a history of injecting drug use. Being tattooed emerged as a statistically significant predictor for infection with genotype 4. The 94.4% prevalence of HCV-RNA among anti-HCV-positive drug users was considerably higher than the 54-86% chronicity rate found globally among HCV-infected patients. The results of this study suggest the existence of separate transmission networks for injecting drug users and non-injecting drug users. Finally, the results suggest that tattooing practices play a role in the spread of HCV among drug users.

Predicting progression to cirrhosis in chronic hepatitis C virus infection

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

Genetic diversity and models of viral evolution for the hepatitis C virus

In this review we discuss the application of theoretical frameworks to the interpretation of viral gene sequence data, with particular reference to the hepatitis C virus (HCV). The increasing availability of such data means that it is now possible (and necessary) to proceed from simple qualitative models of viral evolution, to more quantitative frameworks based on statistical inference, notably population genetics and molecular phylogenetics. We argue that these approaches are invaluable tools to the virologist and are essential for understanding the dynamics of viral infection and the outcome of therapeutic strategies. We use several recent HCV data-sets to illustrate the methods.

Immunopathogenesis of hepatitis C virus infection

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

Interferon responsiveness in patients infected with hepatitis C virus 1b differs depending on viral subtype

BACKGROUND

Genotype 1b of hepatitis C virus (HCV) comprises mainly three subtypes, each named for its geographic prevalence (worldwide, W; Japan, J; and not in Japan, NJ).

AIM

To characterise the newly identified subtypes of genotype 1b and to review factors associated with response to interferon (IFN) for each subtype.

PATIENTS

Chronic hepatitis patients (80 men and 41 women; mean age 48.5 years, range 20.7--69.3) with HCV genotype 1b (W type, n=41; J type, n=38) or genotype 2a (n=42) were treated according to the same IFN protocol. Forty four patients (36.4%) negative for serum HCV RNA six months after cessation of treatment were considered complete responders.

METHODS

Factors associated with complete response were investigated.

RESULTS

Genotype 2a patients had lower viral loads (odds ratio 0.11 (95% confidence intervals (CI) 0.049--0.256)) and a better IFN response (odds ratio 0.25 (95% CI 0.117--0.552)) than genotype 1b patients whereas W type and J type patients had similar viral loads and responses to IFN. IFN response in W type patients was associated with female sex (odds ratio 0.23 (95% CI 0.055--0.983)) and low viral load (odds ratio 84.00 (95% CI 14.04--502.6)) whereas response in J type patients was related to transfusion history (odds ratio 7.20 (95% CI 1.443--35.91)), low viral load (odds ratio 117.0 (95% CI 17.82--768.3)), and genetic mutation in the interferon sensitivity determining region of the virus (odds ratio 0.08 (95% CI 0.013--0.553)). Multivariate analysis found low viral load (odds ratio 64.19 (95% CI 14.66--281.06)) to be the only significant independent factor associated with IFN response.

CONCLUSIONS

Factors associated with IFN responsiveness in HCV infection differ with viral subtype.

HCV genotype and "silent" HBV coinfection: two main risk factors for a more severe liver disease

To evaluate whether HCV genotype and a "silent" HBV infection may be related to a more severe clinical presentation of liver disease, 205 anti-HCV/HCV-RNA positive, HBsAg/anti-HBs negative patients with chronic hepatitis (113 males and 92 females; median age 55 years, range 18-77), were studied on presentation at the Liver Unit from January 1993 to December 1997. Presence of serum anti-HBc, in the absence of HBsAg and anti-HBs, was considered a marker of "silent" HBV infection. Of the 205 patients, 134 had undergone percutaneous liver biopsy. Two main diagnosis groups were established: the mild liver disease group (76 patients), and the severe liver disease group (109 patients); 20 patients who had refused to undergo liver biopsy were not included in the clinical and virological evaluation because the diagnosis was uncertain. The prevalence of severe liver disease was similar in the genotype 1 and non-1 groups (61.3% of 98 patients with genotype 1 and 52.9% of 70 patients with a non-1 genotype). Instead, the 88 patients with "silent" HBV infection showed a higher percentage of severe liver disease than the 97 anti-HBc negative patients (72.7% vs. 46.4%, respectively: P < 0.0005). Of the 88 anti-HBc positive patients, the prevalence of those with severe liver disease was similar in the 32 cases with serum HBV-DNA as detected by PCR and in the 56 HBV-DNA negative (81.2% vs. 67.8%, P = 0.4). The relation between "silent" HBV infection and severe liver disease was observed both in genotype 1 and non-1 infected patients. Nevertheless, the anti-HBc negative patients infected by genotype 1 showed a severe liver disease more frequently than those infected by a non-1 genotype, with a difference that is significant to the statistical analysis (P < 0.05). The findings suggest that "silent" HBV infection in anti-HCV positive chronic hepatitis enhances the severity of the liver disease. Evidence was also found that in patients without "silent" HBV infection there is a correlation between the presence of HCV genotype 1 and the severity of liver disease.

Hepatitis C virus genotypes: distribution and clinical significance in patients with cirrhosis type C seen at tertiary referral centres in Europe

The aim of this study was to evaluate the distribution and clinical significance of hepatitis C virus (HCV) genotypes in European patients with compensated cirrhosis due to hepatitis C (Child class A) seen at tertiary referral centres. HCV genotypes were determined by genotype-specific primer PCR in 255 stored serum samples obtained from cirrhotics followed for a median period of 7 years. Inclusion criteria were biopsy-proven cirrhosis, absence of complications of cirrhosis and exclusion of all other potential causes of chronic liver disease. The proportion of patients with types 1b, 2, 3a, 1a, 4 and 5 were 69%, 19%, 6%, 5%, 0.5% and 0.5%, respectively. Kaplan-Meier 5-year risk of hepatocellular carcinoma (HCC) was 6% and 4% for patients infected by type 1b and non-1b, respectively (P=0.8); the corresponding figures for decompensation were 18% and 7% (P=0.0009) and for event-free survival were 79% and 89% (P=0.09), respectively. After adjustment for baseline clinical and serological features, HCV type 1b did not increase the risk for HCC [adjusted relative risk=1.0 (95% confidence interval=0.47-2.34)], whereas it increased the risk for decompensation by a factor of 3 (1.2-7.4) and decreased event-free survival by a factor of 1.7 (0.9-3.10). In conclusion, type 1b and, to a lesser extent, type 2, are the most common HCV genotypes in European patients with cirrhosis. HCV type 1b is not associated with a greater risk for HCC, but increases the risk for decompensation by threefold in patients with cirrhosis.

Genotype and viral load as prognostic indicators in the treatment of hepatitis C

Interferon-alpha (IFN-alpha), either alone or in combination with ribavirin, is the standard treatment for patients with hepatitis C. However, most patients do not achieve a sustained remission with this treatment regimen. A number of studies have demonstrated that genotype, baseline viral load and/or a decrease in viral load early after treatment induction are the major predictive factors for response to treatment with IFN. Patients with hepatitis C virus (HCV) genotype 1 are more resistant to treatment with IFN, whereas low viral load at baseline and a marked decline in the HCV RNA level during the first 2-12 weeks of IFN therapy are associated with enhanced treatment efficacy. These variables could potentially be used to develop treatment algorithms that tailor therapies for specific clinical situations. Continued development and refinement of such algorithms would facilitate both the selection of patients who are most likely to benefit from therapy and the development of optimal treatment regimens for different patient groups. Predictive factors will also enable clinicians to identify subsets of patients who are not expected to respond well to current treatment. The development of new delivery methods for IFN that produce sustained antiviral pressure may provide a means of treating these previously difficult-to-treat patient groups.

Clinical significance of hepatitis C virus genotypes

The advent of genotyping assays has stimulated investigators around the world to study the molecular epidemiology of hepatitis C virus (HCV) infection in specific patient categories, as well as possible correlations with the clinical and histological features of chronic liver disease and response to antiviral treatment. While a general consensus has been reached on the worldwide epidemiology and distribution of HCV types in certain risk categories (i.e. intravenous drug users), the association between genotype 1b and severe liver disease is still controversial. Although generalized use of genotyping is not presently recommended for clinical or epidemiological monitoring, several studies emphasize to the importance of HCV genotyping as part of a therapeutic algorithm. This recommendation is based on overwhelming evidence in support of a correlation between genotype 1 and a poor response to interferon-a alone or in combination with ribavirin.

Perspectives for the treatment of infections with Flaviviridae

The family Flaviviridae contains three genera: Hepacivirus, Flavivirus, and Pestivirus. Worldwide, more than 170 million people are chronically infected with Hepatitis C virus and are at risk of developing cirrhosis and/or liver cancer. In addition, infections with arthropod-borne flaviviruses (such as dengue fever, Japanese encephalitis, tick-borne encephalitis, St. Louis encephalitis, Murray Valley encephalitis, West Nile, and yellow fever viruses) are emerging throughout the world. The pestiviruses have a serious impact on livestock. Unfortunately, no specific antiviral therapy is available for the treatment or the prevention of infections with members of the Flaviviridae. Ongoing research has identified possible targets for inhibition, including binding of the virus to the cell, uptake of the virus into the cell, the internal ribosome entry site of hepaciviruses and pestiviruses, the capping mechanism of flaviviruses, the viral proteases, the viral RNA-dependent RNA polymerase, and the viral helicase. In light of recent developments, the prevalence of infections caused by these viruses, the disease spectrum, and the impact of infections, different strategies that could be pursued to specifically inhibit viral targets and animal models that are available to study the pathogenesis and antiviral strategies are reviewed.

Chronic hepatitis C in Sweden: genotype distribution over time in different epidemiological settings

Hepatitis C virus (HCV) strains are divided into 6 genotypes and several subtypes. Recent studies reported a change in the relative frequency of genotypes within certain regions. We studied the HCV genotype in 312 Swedish patients with chronic hepatitis C, using a core region primer-specific PCR, and grouped the patients according to parenteral risk factors. The date of infection could be estimated in 127 cases. Genotypes 1a (35%) and 3 (31%) were the most common genotypes, followed by genotype 2 (17%), while only 6% had genotype 1b. Genotype 3 was relatively more frequent among subjects infected sexually or by intravenous drug use. The genotype distribution was different from that in studies from other parts of the world, with a lower frequency of genotype 1 (especially 1b) and a higher frequency of genotype 3. The frequency of genotype 1b has decreased and genotype 3 increased over time. The reasons for a different distribution of genotypes in Sweden, compared with other countries, might be a relatively recent introduction of HCV into the population, or a different pattern of transmission.

Steatosis and bile duct damage in chronic hepatitis C: distribution and relationships in a group of Northern Italian patients

BACKGROUND/AIMS

Hepatitis C virus (HCV) related disease follows a long, benign course and most affected patients have mild disease. Liver biopsy is mandatory to grade and stage the disease. Characteristic, though non-specific, HCV histological lesions such as bile duct damage and steatosis have been singled out but their association with non-histological parameters has not been completely defined. Our aim was to study the relationships among these histological lesions and clinical, biochemical, functional and virological characteristics in a group of Northern Italian patients with chronic hepatitis.

METHODS

We studied 172 patients with HCV-related chronic hepatitis. Patients were divided into groups on the basis of histology including bile duct damage and steatosis. Clinical, biochemical, functional and virological profiles were related to histological findings.

RESULTS

Histological grading and staging of disease increased as the age of patients increased. Steatosis was present in 70% of our patients and was related to a higher degree of fibrosis and to decreased functional activity. The prevalence of bile duct damage was 20%. This lesion was present in older patients with higher staging and impaired liver function. Biochemically it was associated with an increase in aspartate aminotransferase, gammaglutamyltranspeptidase, alkaline phosphatase, and total bilirubin.

CONCLUSIONS

In the population we studied, HCV chronic hepatitis was predominantly a mild disease. Moreover both steatosis and bile duct damage were also mild. Steatosis was associated with fibrosis and this might influence liver metabolic function. Bile duct lesions were found in older patients with advanced disease showing biochemical evidence ofcholestasis. The molecular role HCV might play in the pathogenesis of these histological features should be addressed in further studies.

Chronic hepatitis C virus infections in brazilian patients: association with genotypes, clinical parameters and response to long term alpha interferon therapy

The present study assessed the clinical significance of hepatitis C virus (HCV) genotypes and their influence on response to long term recombinant-interferon-alpha (r-IFN-alpha) therapy in Brazilian patients. One hundred and thirty samples from patients previously genotyped for the HCV and with histologically confirmed chronic hepatitis C (CH-C) were evaluated for clinical and epidemiological parameters (sex, age, time of HCV infection and transmission routes). No difference in disease activity, sex, age or mode and time of transmission were seen among patients infected with HCV types 1, 2 or 3. One hundred and thirteen of them were treated with 3 million units of r-IFN-alpha, 3 times a week for 12 months. Initial response (IR) was significantly better in patients with genotype 2 (100%) and 3 (46%) infections than in patients with genotype 1 (29%) (p < 0. 005). Among subtypes, difference in IR was observed between 1b and 2 (p < 0.005), and between 1b and 3a (p < 0.05). Sustained response (SR) was observed in 12% for (sub)type 1a, 13% for 1b, 19% for 3a, and 40% for type 2; significant differences were found between 1b and 2 (p < 0.001), and between 1b and 3a (p < 0.05). Moreover, presence of cirrhosis was significantly associated with non response and response with relapse (p < 0.05). In conclusion, non-1 HCV genotype and lack of histological diagnosis of cirrhosis were the only baseline features associated with sustained response to treatment. These data indicate that HCV genotyping may have prognostic relevance in the responsiveness to r-IFN-alpha therapy in Brazilian patients with chronic HCV infection, as seen in other reports worldwide.