A second-generation method of genotyping hepatitis C virus by the polymerase chain reaction with sense and antisense primers deduced from the core gene

Identification of Genotype 2 HCV in Serotype-1 Hepatitis C Patients Unresponsive to Daclatasvir plus Asunaprevir Treatment

It is important to determine the genotypes or serotypes of hepatitis C virus (HCV) in patients before treatment with direct-acting antiviral agents (DAAs), because the effects of DAAs differ among genotypes. In Japan, two tests for HCV typing are available clinically, but only serotyping, not genotyping, is approved by the public health insurance. Although most serotype-1 Japanese patients are infected with genotype 1b HCV, it is known that a small proportion of patients show different results from two typing methods. This study focused on such patients and the effectiveness of treatment with daclatasvir plus asunaprevir (DCV/ASV) was evaluated. We analyzed 644 DCV/ASV-treated patients with serotype 1 or genotype 1b, and among them, 166 serotype-1 patients received a commercial-based direct sequencing (DS) test for resistant-associated variants of genotype 1b HCV. We found four patients (2.4%) with DS test failure, suggesting that the PCR primers targeting genotype 1b may not match. Importantly, none of the four patients achieved a sustained virological response. Our in-house DS test analyzing the 5'-untranslated region and coding regions for NS4 and NS5B of HCV showed that three of the four patients were infected with genotype 2 HCV, and one patient was infected with genotype 1a HCV. No recombinant virus of different genotypes was found. This study indicates that a subset of serotype-1 hepatitis C patients is infected with HCV of genotype 2 or 1a in Japan and that DCV/ASV is not effective for such patients. Thus, attention should be paid to DAA treatment without HCV genotyping.

Disadvantages of peginterferon and ribavirin treatment in older patients with chronic hepatitis C: an analysis using the propensity score

PURPOSE

Peginterferon (PEG-IFN) and ribavirin (RBV) combination treatment for patients with chronic hepatitis C (CHC), infected by genotype-1 hepatitis C virus with high viral loads, results in a sustained viral response (SVR) in ~50%. However, a trend of decreasing SVR in the older patients has been reported. In the present study, we verified this trend of treatment efficacy in older patients using the propensity score (PS).

METHODS

We conducted a survey of 327 patients with CHC (genotype 1 and high viral loads) who were treated with PEG-IFN and RBV for 48 weeks. The SVR rate was compared between patients =60 and <60 years of age. Because backgrounds of these patients differed considerably, we verified this efficacy between the older (n = 102) and younger (n = 102) patients matched for gender, body weight, platelets (PLT), and red blood cell (RBC) counts using PS.

RESULTS

The total SVR rate was 42.9% (161/327); this rate decreased with increasing age and was lower in the older patients (≥60 years: 41.5%, <60 years: 54.3%, P = 0.0245). Moreover, younger age was a significant factor for SVR. After correction by PS, the SVR in older patients remained significantly lower (≥60 years: 43.1%, <60 years: 57.8%, P = 0.0497). In addition, RBC counts and hemoglobin (Hgb) concentrations, as well as RBV adherence in the older patients, decreased with this treatment, although there were no significant differences in pretreatment RBC and Hgb levels.

CONCLUSIONS

The analysis using PS indicated that RBV adherence in the older patients decreased even if they did not have lower pretreatment RBC and Hgb levels.

Peginterferon alpha-2b and ribavirin for the treatment of chronic hepatitis C in Japanese pediatric and young adult patients: a survey of the Japan Society of Pediatric Hepatology

OBJECTIVES

Only a few studies on the treatment with peginterferon-2b and ribavirin are available in children with chronic hepatitis C virus (HCV). The aim of this study was to evaluate both the efficacy and the safety of the treatment in Japanese children and young adults.

METHODS

Twenty-two of 41 members of the Japan Society of Pediatric Hepatology reported on 37 cases who were treated with peginterferon and ribavirin.

RESULTS

Of the 37 patients, 29 have completed the treatment and all of them cleared the HCV virus. Three patients are still being treated, whereas the remaining five failed to complete the treatment. Cessation of the treatment was because of the nonresponsiveness (n=3), the expense of the treatment (n = 1), or lethargy (n=1). After excluding the three patients, who were continuing the treatment and one who has not completed the 24-week follow-up period, from the 37 patients, 33 were available for sustained virologic response (SVR) analysis. After 4 weeks of follow-up, one of the 33 relapsed. An intention-to-treat analysis showed that 27 of the 33 (81.8%) achieved a SVR. The only factor significantly associated with SVR was their virologic response status at week 4.

CONCLUSION

The results showed that the present patients infected with HCV and treated with peginterferon-2b and ribavirin achieved a remarkably high SVR rate. In addition, most of the patients achieved a SVR once they showed a virologic response at week 4. The combination of peginterferon-alpha with ribavirin may be considered as a standard therapy for children and young adults.

Molecular analysis of transmission of hepatitis C virus in a nurse who acquired acute hepatitis C after caring for a viremic patient with epistaxis

A 23-year-old nurse (HC-IP) developed acute hepatitis C. Intrafamilial transmission of hepatitis C virus (HCV) was suspected initially because her parents were carriers of HCV of the same genotype (1b) as that of Patient HC-IP. However, the HCV isolate from Patient HC-IP and those from her parents shared identities of only 92.4-92.7% in the 1,087-nucleotide (nt) sequence within the NS5B region. It was then suspected that she contracted HCV infection during medical practice. Sixteen patients with antibodies to HCV (anti-HCV) were hospitalized 1-3 months before she became positive for anti-HCV. Upon analysis of stored serum samples, 14 of the 16 patients were found to be positive for HCV RNA, and 9 of the 14 viremic patients had genotype 1b HCV. Although the shared identities between the HCV isolate from Patient HC-IP and those from eight of the nine patients were merely 90.6-93.9% within the 1,087-nt NS5B sequence, the HCV isolate from the remaining one patient (HC-P12) was 99.7% identical to that from Patient HC-IP. Upon analysis of the E1 and E2 junctional region including hypervariable region 1 (283 nt), there was a close relationship (99.3-100%) between clones obtained from Patients HC-IP and HC-P12. Although the nurse HC-IP had a finger injury, she took care of Patient HC-P12, a 70-year-old man with HCV-related cirrhosis and recurrent epistaxis, occasionally without wearing protective gloves. This study indicates the occurrence of HCV transmission by exposure of nonintact skin to blood in health care settings.

IL-10 promoter gene polymorphisms and sustained response to combination therapy in Taiwanese chronic hepatitis C patients

BACKGROUND AND AIMS

Host genetic factors may affect clinical outcomes of hepatitis C virus (HCV) infection; however, the possible mechanisms remain largely unknown. The role of immunopathogenesis in chronic hepatitis C leads to extensive exploration of host immunity including inflammatory cytokines.

METHODS

We examined interleukin 10 (IL-10) promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site and studied their association with response to 24 weeks of pegylated interferon plus ribavirin treatment in 143 chronic hepatitis C patients, of whom 97 (67.8%) achieved a sustained virologic response (SVR). In addition, 134 healthy adults were used as controls.

RESULTS

Of chronic hepatitis C patients, 111 (77.6%) were genotype 1 infection, 32 (22.4%) were genotype 2 infection. Patients with sustained virologic response were younger and had higher pretreatment ALT levels than those without. No statistical difference was found between chronic hepatitis C patients who achieved SVR or not in terms of gender, HCV genotype, pretreatment HCV RNA levels, and severity of liver disease. The serum IL-10 levels were comparable between healthy controls and chronic hepatitis C patients as well as between HCV patients with and without SVR. The distribution of IL-10 promoter gene polymorphisms at positions -1082, -819, and -592 relative to transcription start site was comparable between HCV patients and healthy controls as well as HCV patients with and without SVR. A high frequency of ATA haplotype of common IL-10 promoter gene SNPs was found in both chronic hepatitis C patients (70.3%) and healthy controls (69.8%). However, ATA haplotype was not associated with SVR in chronic hepatitis C patients.

CONCLUSIONS

Our data fail to demonstrate the influence of IL-10 promoter gene polymorphisms on the response to combination therapy in Taiwanese chronic hepatitis C patients. The impact of genetic variations in IL-10 haplotype on the response to anti-HCV treatment among different ethnic populations deserves further examination.

Prevalence and genotype distribution of hepatitis C virus among apparently healthy individuals in Mongolia: a population-based nationwide study

BACKGROUND AND AIMS

Hepatitis C virus (HCV) is one of the major causes of liver cirrhosis and hepatocellular carcinoma (HCC) in Mongolia. However, there are no data concerning nationwide prevalence of HCV infection in Mongolia. We intended to investigate the population-based prevalence of HCV infection and genotype distribution among 1512 apparently healthy individuals in this country.

METHODS

Between April 2003 and December 2005, sera from 1512 residents of Ulaanbaatar and 12 provinces were collected by two-stage cluster random sampling, and anti-HCV was tested. Anti-HCV-positive samples were tested for HCV RNA by reverse transcription polymerase chain reaction, and HCV genotype was determined.

RESULTS

The mean age of the subjects was 46.2+/-17.8 years, and 812 (53.7%) were male. Overall, the prevalence of anti-HCV was 15.6% (236/1512) and HCV RNA was detected in 167 subjects (11.0%), with the most common genotype being 1b (165/167, 98.8%). When the HCV RNA-positive subjects were categorized by decade of age, the prevalence in each age group was as follows: 2.5% in subjects /=61 years of age. The seroprevalence of anti-HCV in a risk group, nurses, was not significantly different from the general population in each decade of age (P>0.05).

CONCLUSIONS

Approximately 11.0% of apparently healthy population had detectable HCV RNA in Mongolia, and the predominant genotype of HCV was 1b. Preventive and therapeutic strategies for chronic hepatitis C are urgently warranted in this HCV-endemic area.

Hepatitis C virus infection and interferon therapy in patients with Down syndrome

BACKGROUND

The clinical features of hepatitis C virus (HCV)-associated liver diseases, or the efficacy of interferon (IFN) therapy in children with Down syndrome (DS) remain to be elucidated. The purpose of the present paper was to survey the features of liver diseases in this subset of children and evaluate the efficacy of IFN treatment in those patients.

METHODS

A questionnaire was sent to 41 members of the Japan Society of Pediatric Hepatology. Ten of them reported on 11 patients with DS who had concomitant chronic HCV infection, providing information on liver disease and the response to IFN treatment.

RESULTS

Interferon therapy of 24 weeks duration using natural IFN-alpha was instituted in six of the 11 patients with DS, but none of the six patients cleared HCV-RNA from their serum. Among 12 age- and sex-matched control children who were treated with IFN using the same regimen against chronic HCV infection, half of them had a favorable response to IFN therapy with a sustained clearance of HCV-RNA from their serum. The major baseline features including alanine aminotransferase levels, HCV genotype and viral load were not apparently different between the six patients with DS and the 12 controls.

CONCLUSIONS

IFN therapy for HCV infection in patients with DS may be unfavorable as compared with non-DS children.

Monitoring serum hepatitis C virus (HCV) RNA in patients with HCV-infected CD20-positive B-cell lymphoma undergoing rituximab combination chemotherapy

Several studies have shown that the frequency of hepatitis C virus (HCV) infection is high in patients with B-cell non-Hodgkin's lymphoma (NHL). In these studies, liver dysfunction during chemotherapy has been demonstrated, but changes in HCV ribonucleic acid (RNA) levels during chemotherapy have not been well documented. In this study, we monitored serum HCV RNA levels and liver function in five HCV-infected patients with B-cell NHL undergoing treatment with rituximab-combination chemotherapy. Increased HCV RNA levels during or after the chemotherapy were observed in all five patients, and a significant increase in transaminases was seen in one case. In this case, serum HCV RNA level dramatically decreased at the time of the increase of transaminases, and this suggested that the cause of liver damage was an immune reaction against hepatocytes with HCV and not any anticancer drug induced liver toxicity. Monitoring of serum HCV RNA levels and transaminases may be helpful to understand the cause of liver dysfunction in patients receiving chemotherapy. However, increases of HCV viral load were not associated with the occurrence of liver dysfunction in this study. Further studies will be necessary to investigate more fully the relationship between changes in HCV viral load and liver function during chemotherapy for HCV-infected patients.

Impact of hepatitis B virus (HBV) X gene integration in liver tissue on hepatocellular carcinoma development in serologically HBV-negative chronic hepatitis C patients

BACKGROUND/AIMS

We analyzed hepatitis B virus (HBV) X gene integration in hepatocytes of HBV-negative, chronic hepatitis C (CH-C) patients with mild fibrosis, and prospectively followed these patients for the development of hepatocellular carcinoma (HCC).

METHODS

The study included 39 HBV-negative CH-C patients with mild fibrosis. HBV-X integration was determined by Alu-PCR analysis of liver specimens obtained by fine-needle biopsy.

RESULTS

Integration of HBV-X gene sequence into liver genome occurred in 9 of the 39 patients. Six of the 39 patients developed HCC during the 12-year follow-up period. No significant difference was found in the incidence of HCC between patients with and without HBV-X integration. However, the two patients with HBV-X integration who developed HCC did not have cirrhosis at the time when HCC was diagnosed, whereas the four patients without HBV-X integration who developed HCC did have cirrhosis.

CONCLUSIONS

Our findings suggest that HBV-X integration detected at the mild fibrosis stage might not indicate a high risk for HCC. HBV-X integration may be associated with HCC development in the absence of cirrhosis. However, we did not find evidence that HBV-X integration directly plays a role in hepatocarcinogenesis in CH-C patients. Further studies will be needed to clarify this point.

Re-evaluation of the true rate of hepatitis C virus mother-to-child transmission and its novel risk factors based on our two prospective studies

OBJECTIVE

To re-evaluate the true hepatitis C virus (HCV) mother-to-child transmission (MTCT) rate and its novel risk factors.

STUDY DESIGN

A comparative study based on our own two prospective studies done during the two periods, 'early' (1989-1994) and 'recent' (1995-2004).

RESULTS

All carrier infants became HCV RNA-positive within 3 months after birth. The MTCT and de-carrier rates were, respectively, higher (14.2%) and lower (16.7%) in the recent period, although liver dysfunction of carrier infants was found very frequently (66.7%) in both groups. MTCT occurred significantly when the maternal viral load, serum alanine aminotransferase (sALT) levels and blood loss at delivery were, respectively, more than 10(5) copies/mL, 110 IU/L, and 500 g. No MTCT was found when elective cesarean section was done.

CONCLUSIONS

The true HCV MTCT and de-carrier rates were found to be much higher and lower than those reported previously. The maternal liver dysfunction (sALT >or=110 IU/mL) and blood loss (>or=500 g) at delivery are the next risk factors to maternal viral load (>or=10(5) copies/mL) for MTCT.

Prevalence of hepatitis B, C, and delta virus infections among children in Mongolia: progress in childhood immunization

Mongolia is highly endemic for hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections among apparently healthy adults. However, the age-specific prevalence of ongoing HBV, HCV, and HDV infections among children in Mongolia remains unknown. Therefore, samples obtained from a total of 655 apparently healthy children of 0.3-15 years of age (307 boys and 348 girls; age, mean +/- standard deviation [SD], 8.4 +/- 4.2 years) living in Mongolia, between October 2005 and January 2006, were tested for serological and molecular markers of HBV, HCV, and HDV infections. Although 88.7% of the 655 children studied were immunized against hepatitis B, 64 (9.8%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA and 13 (2.0%) for HDV RNA. Twenty-seven children (4.1%) had detectable HCV RNA. Collectively, 82 (12.5%) were viremic for one or more of these viruses, including eight children with dual viremia of HBV/HCV and one child with triple HBV/HCV/HDV viremia. When children without anti-HBc, anti-HCV and anti-HDV IgG (n = 510) served as a control, a history of hospitalization was significantly associated with HBV viremia (P < 0.0001), anti-HBc positivity (P < 0.0001), and HCV viremia (P = 0.0001). HBsAg mutation was found in 18 (31.6%) of the 57 children with viremia, including those at amino acid position 126, 127, 129, 131, 134, 143 or 144. There were no significant differences in the frequency of HBsAg mutation in relation to age, sex, and hepatitis B vaccination status of the children, suggesting that HBsAg mutation plays a limited role in failure of vaccination in Mongolia.

Hepatitis C virus genetic variability in patients undergoing antiviral therapy

Hepatitis C virus (HCV) has been the subject of intense research and clinical investigations due to its worldwide prevalence and major role in chronic liver disease. Like most RNA viruses, HCV circulates in vivo as a complex population of different but closely related viral variants, commonly referred to as a quasispecies. Recent studies suggest that ribavirin might exert an antiviral effect against HCV through both mutagenic effect and an impairment of RNA replication. The introduction of alpha interferon (IFN-alpha) plus ribavirin combination therapy was an important breakthrough in the treatment of chronic HCV infection. However, the rate of sustained virological response is still unsatisfactory, particularly in patients infected with HCV genotype 1. Viral persistence, a hallmark of HCV, may result from a dynamic control of the host response by the virus. In children with chronic HCV infection, the viral population is initially highly homogeneous, but diversifies during prolonged infection which seems to be a common event during chronic hepatitis C in childhood. Coinfection of human immunodeficiency virus 1 (HIV-1) patients by HCV can complicate the treatment of these patients with highly active antiretroviral therapy (HAART). HIV coinfection is associated with a decrease of HCV quasispecies variability, which appears to be reversed by effective HAART.

Multiplex real-time reverse transcription-PCR assay for determination of hepatitis C virus genotypes

A variety of methods have been used to determine hepatitis C virus (HCV) genotypes. Because therapeutic decisions for chronic HCV-related hepatitis are made on the basis of genotype, it is important that genotype be accurately determined by clinical laboratories. Existing methods are often subjective, inaccurate, manual, time-consuming, and contamination prone. We therefore evaluated real-time reverse transcription-PCR (RT-PCR) reagents that have recently become commercially available (Abbott HCV Genotype ASR). The assay developed by our laboratory starts with purified RNA and can be performed in 4 to 5 h. An initial evaluation of 479 samples was done with a restriction fragment length polymorphism (RFLP) method and the RT-PCR assay, and discrepant samples were sequenced. An additional 1,200 samples were then tested, and data from all assays were used to evaluate the efficiency and specificity of each genotype-specific reaction. Good correlation between results by the two methods was seen. Discrepant samples included those indeterminate by the RT-PCR assay (n = 110) and a subset that were incorrectly called 2a by the RFLP method (n = 75). The real-time RT-PCR assay performed well with genotype 1, 2, and 3 samples. Inadequate numbers of samples were available to evaluate fully genotypes 4, 5, and 6. Analysis of each primer-probe set demonstrated that weak cross-reactive amplifications were common but usually did not interfere with the genotype determination. However, in about 1% of samples, two or more genotypes amplified at roughly equivalent amounts. Further studies are necessary to determine whether these mixed-genotype samples are true mixtures or a reflection of occasional cross-reactive amplifications.

Epidemiology of hepatitis C virus (HCV) infection

Hepatitis C virus remains a large health care burden to the world. Incidence rates across the world fluctuate and are difficult to calculate given the asymptomatic, often latent nature of the disease prior to clinical presentation. Prevalence rates across the world have changed as well with more countries aware of transfusion-related hepatitis C and more and more evidence supporting intravenous drug use as the leading risk factor of spread of the virus. This article reviews current hepatitis C virus prevalence and genotype data and examines the different risk factors associated with the virus.

Genetic diversity and evolution of hepatitis C virus in the Latin American region

Hepatitis C virus (HCV) has been the subject of intense research and clinical investigations, as a consequence of the recognition of its major role in human disease. HCV evolution is a highly dynamic process. HCV exploits all known mechanisms of genetic variation, such as recombination and mutation, to ensure its survival. Like most RNA viruses, HCV circulates in vivo as a complex population of different but closely related variants, commonly referred to as a quasi species. This work describes the genetic variability of HCV in Latin America, with special emphasis on its diversification and recombination in this area of the world, and discusses how our knowledge of these issues can contribute to its control.

High prevalence of dual or triple infection of hepatitis B, C, and delta viruses among patients with chronic liver disease in Mongolia

Mongolia is known for its high endemicity for hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections among apparently healthy individuals. However, there are little or no data on the prevalence and genotype distribution of HBV, HCV, and HDV among patients with chronic liver disease in Mongolia. Therefore, serum samples obtained in 2004 from 207 patients (age, mean+/-standard deviation, 51.0+/-11.9 years) including those with chronic hepatitis (n=90), liver cirrhosis (n=41), and hepatocellular carcinoma (n=76) were tested for serological and molecular markers of HBV, HCV, and HDV infections. Of the 207 patients, 144 (69.6%), 106 (51.2%), and 117 (56.5%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA, HCV RNA, and HDV RNA, respectively. Collectively, 172 patients (83.1%) were viremic for one or more of these viruses, including dual viremia of HBV/HDV (26.6%) or HBV/HCV (7.7%) and triple HBV/HCV/HDV viremia (30.0%). Of note, triple ongoing infection was significantly more frequent among patients with hepatocellular carcinoma than among those with chronic hepatitis (63.2% vs. 14.4%, P<0.0001). One hundred sixty patients (77.3%) had a history of blood transfusion and/or surgery. The distribution of HBV genotypes among the 116 HBV-viremic patients was: A (0.9%), B (0.9%), C (6.0%), D (88.8%), and C plus D (3.4%). All 117 HDV isolates were classified into genotype I. The 106 HCV RNA-positive samples were typed as genotype 1b (92.5%), 2a (0.9%), or 1b plus 2a (6.6%); mixed infection of two distinct HCV genotypes was found exclusively in the patients with hepatocellular carcinoma.

High prevalence of hepatitis B, C and delta virus infections among blood donors in Mongolia

Serum samples obtained from 289 first-time and 114 repeat donors at the Blood Center of Mongolia (MBC) were tested for serological and molecular markers of hepatitis B virus (HBV), hepatitis C virus (HCV), and hepatitis delta virus (HDV) infections. Among the 403 blood donors, 33 (8.2%), 21 (5.2%), and 27 (6.7%) tested positive for hepatitis B surface antigen (HBsAg) and/or HBV DNA, HCV RNA, and HDV RNA, respectively. Collectively, 55 donors were viremic for one or more of these viruses, and included 54 first-time donors (18.7%) and 1 repeat donor (0.9%) (P < 0.0001). One discrepant case with HBsAg detectable only at MBC was negative for HBsAg, HBV DNA and anti-HBc in this study. Four donors who were HCV-viremic in this study were negative for anti-HCV by the MBC method. Further efforts to increase the sensitivity and specificity of the currently-used tests are urgently required in Mongolia. Three donors who were positive for anti-HBc and anti-HDV but negative for HBsAg, had both HBV DNA and HDV RNA. This suggests that introduction of a new anti-HDV serological test is useful for not only HDV screening but also HBV screening of anti-HBc-positive, HBsAg negative donors, considering a possibility of viral interference by coexisting HDV.

Changes in hepatitis C virus (HCV) antibody status in patients with chronic hepatitis C after eradication of HCV infection by interferon therapy

BACKGROUND

Changes in hepatitis C virus (HCV) antibody status were followed for 10 years after the eradication of HCV by interferon (IFN) therapy in 30 patients with chronic hepatitis C who showed a sustained virological response.

METHODS

HCV core antibody titer, third-generation HCV recombinant immunoblot assay (RIBA) grade (measuring the presence of antibodies for core, NS3, NS4, and NS5 antigens), and genotype-specific antibodies to the HCV NS4 region were measured annually with commercially available kits for these antibodies.

RESULTS

For grade of HCV antibody determined by RIBA, the most significant decrease was observed with anti-NS5 antibody, followed by anti-NS4, anti-NS3, and anti-core antibodies, in that order. Tests for anti-NS5 and anti-NS4 antibodies had negative results in almost 50% of patients 10 years after eradication of HCV. In contrast, the results of tests for anti-core antibody were still markedly positive in most patients. However, anti-core antibody titer decreased continuously during the 10-year follow-up period. Antibodies to the NS4 region specific for HCV genotypes 1 and 2 also decreased during the follow-up period. Differences in the rate at which antibody titers decreased were observed between antibodies for genotypes 1 and 2; as a consequence, the serological type of HCV changed during the follow-up period in some patients.

CONCLUSIONS

HCV antibody titer appears to continue to decrease during the 10 years after eradication of HCV by IFN therapy.

Epidemiology of blood donors in Japan, positive for hepatitis B virus and hepatitis C virus by nucleic acid amplification testing

BACKGROUND AND OBJECTIVES

The Japanese Red Cross screens seronegative blood donors by nucleic acid amplification testing (NAT) for hepatitis B, hepatitis C and human immunodeficiency virus-1 markers. NAT-positive donors thus identified seemed to have a different infectious background from serologically positive donors. The purpose of our study was to characterize this background in the hepatitis B virus (HBV) and hepatitis C virus (HCV) NAT-positive donors.

MATERIALS AND METHODS

Some 328 HBV DNA-positive and 44 HCV RNA-positive donors were detected by NAT testing of seronegative blood donors. These were characterized regarding age, gender and genotype of HBV and HCV.

RESULTS

Those who were HBV NAT-positive were mainly young, in particular teenage girls. In Japan, genotypes C and B have previously been dominant, but recently genotype A has increased, and genotype H was recently detected. In HBV NAT-positive donors, the rate of genotype A was high (12.2%) compared with patients in hospital (1.7-2%). Donors who were HCV NAT-positive were also young, but mostly men in their twenties. The ratio of genotype 1b to 2a or 1b to 2b in HCV NAT-positive donors differed from that of hospitalized patients in Japan. We did not find genotype 1a, which is dominant in the USA.

CONCLUSIONS

The high-risk donors detected by NAT were mainly young, with a different distribution of genotypes from that of hospitalized patients, regarding both HBV and HCV. The rare HBV genotype H has been found for the first time in Japan. The findings reflect the present spread of hepatitis viruses B and C.

Prevalence and clinical implications of occult hepatitis B viral infection in hemophilia patients in Japan

The prevalence and clinical implications of occult hepatitis B virus (HBV) infection were investigated in the Japanese patients with hemophilia in whom a high prevalence of infection with transfusion-transmissible viruses has been reported. HBV DNA was detected in the sera of 22 of 43 (51.2%) patients with hemophilia who were negative for HBV surface antigen (HBs), indicating that these patients had occult HBV infection. No factor, including age, type or severity of hemophilia, presence of HBs or HBV core (HBc) antibody, or coinfection with hepatitis C virus (HCV) or human immunodeficiency virus (HIV) was associated with occult HBV infection, except for high anti-HBc titer and/or coinfection with HCV genotype 1 (1a or 1b). In general, occult HBV infection did not appear to have significant clinical implications. However, in patients in whom HBV was detected by PCR specific for the surface (S)-region, higher alanine aminotransferase levels were observed. The genotype of the occult HBV in the present study was exclusively the domestic type indigenous to Japan (genotype C), suggesting a different route of transmission for HBV in comparison to HCV and HIV in this population.

Molecular diagnosis of viral hepatitis

Molecular biology-based assays are invaluable tools for the management of chronic viral hepatitis. They can be used to test blood donations, diagnose active infection, help to establish the prognosis, guide treatment decisions, and assess the virological response to therapy. This article reviews current molecular biology-based techniques and assays, and their practical use in the management of hepatitis B and C virus infection.

Effects of HAART on hepatitis C, hepatitis G, and TT virus in multiply coinfected HIV-positive patients with haemophilia

In multiply coinfected human immunodeficiency virus (HIV)-positive patients, we investigated the effects of high-activity antiretroviral therapy (HAART) using HIV protease inhibitors on three other viruses: hepatitis C virus (HCV), hepatitis G virus (HGV), and TT virus (TTV). Viral concentrations were measured serially by polymerase chain reaction methods in five patients with quadruple infection (HIV, HCV, HGV, and TTV) and in two patients with triple infection (HIV, HCV, and HGV) before and during HAART. In addition, CD4+ cell counts and serum alanine aminotransferase (ALT) levels were measured serially. Generally we observed no difference in serum HCV RNA, HGV RNA, or TTV DNA concentrations between samples obtained before and after initiation of HAART, whereas HIV RNA concentration decreased and CD4 counts increased in most patients. However, two patients had markedly decreased concentrations of HCV RNA and HGV RNA, respectively, more than 12 months after beginning HAART. Normalization of serum ALT levels was observed in a patient with decline of HCV RNA concentrations. No interactions were observed among these four viruses. HAART had no apparent direct effects on HCV, HGV, or TTV. Further studies will be required to elucidate whether the restoration of immune status through suppression of HIV replication by HAART may affect HCV or HGV RNA concentrations.

Effect of interferon therapy on Japanese chronic hepatitis C virus patients with anti-liver/kidney microsome autoantibody type 1

AIM

The aim of this study was to determine the prevalence of anti-liver/kidney microsome autoantibody type 1 (anti-LKM-1) among hepatitis C virus (HCV)-infected Japanese patients at various stages (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma), and to assess the influence of anti-LKM-1 on interferon therapy.

METHODS

A total of 390 serum samples from 215 HCV-infected patients with chronic hepatitis (HCV-CH), 81 HCV-infected patients with liver cirrhosis (HCV-LC), and 94 HCV-HCC infected patients were subjected to examination. Ninety-one HBsAg-positive patients and 137 healthy subjects served as controls. Anti-liver/kidney microsome autoantibody type 1 was determined by using a newly developed ELISA using recombinant cytochrome P450 IID6 as the antigen.

RESULTS

Anti-liver/kidney microsome autoantibody type 1 was detected in six of the 390 (1.5%) chronic HCV-infected patients (four were HCV-CH and two were HCV-LC); in contrast, it was not detected in control groups. Among the 110 HCV-CH patients treated with interferon (IFN), four were positive for anti-LKM-1. No change in anti-LKM-1 immunoreactivity from negative to positive during interferon therapy was observed. Moreover, no increase in the serum alanine aminotransferase level was observed in these four patients with anti-LKM-1.

CONCLUSION

Our study indicates that: (i) anti-LKM-1 does not aggravate the liver disease associated with HCV infection; and (ii) no change in anti-LKM-1 immunoreactivity from negative to positive or no aggravations of liver dysfunction were observed among HCV-CH patients during the IFN therapy for Japanese patients with liver disease.

Low frequency of HLA-DRB1*11 in hepatitis C virus induced end stage liver disease

Hepatitis C virus (HCV) infection becomes chronic in more than 70% of patients, leading to end stage liver disease in about 20-30% of these patients. Apart from the virus itself, host factors that modulate the immune response are likely to be involved in determining the outcome of HCV infection. Studies on the association of human leucocyte antigens (HLAs) and HCV infection have shown inconsistent results. Selection of patient subgroups may be crucial. However, any association relevant to HCV disease progression will become evident, especially in those patients with end stage liver disease. Therefore, we analysed the phenotype frequencies of HLA antigens in two groups of 69 and 39 patients with HCV induced liver cirrhosis who had received a transplant or were awaiting liver transplantation. The first group was typed serologically and compared with 331 blood and liver donors. The second group, prospectively HLA typed by a polymerase chain reaction-sequence specific oligonucleotide (PCR-SSO) procedure for HLA-DRB and DQB alleles, was compared with another 170 PCR-SSO typed and randomly selected blood donors. Decreased frequencies for HLA-DR5 and HLA-DQ3 were found in one group of patients with HCV induced liver cirrhosis compared with the control groups. In the second analysis comparing 39 patients with end stage liver cirrhosis with blood donors, we confirmed the significant decrease in HLA-DRB1*11 and HLA-DQB1*03, which corresponded to serological HLA-DR5 and HLA-DQ3 antigens, respectively. Our results show that the presence of HLA-DRB1*11 and HLA-DQB1*03 alleles is associated with a reduced risk for the development of HCV induced end stage liver disease.

Risk factors for hepatocellular carcinoma in Turkey

The contribution of hepatitis B, hepatitis C, and excess alcohol intake to the development of hepatocellular carcinoma in Turkey was assessed. The study was conducted through a questionnaire sent to seven major medical referral centers in different regions of Turkey and is based on 207 patients seen in the period 1994-1997. Of the seven centers, two were located in West Turkey (54 patients), two were in Central Turkey (85 patients), and two were in south and southeast Turkey (68 patients). In 196 of the 207 patients (94.7%), there was a history of chronic liver disease, and in 180 patients (87%) liver cirrhosis was documented. Of the 207 patients, 116 (56%) had hepatitis B, 48 (23.2%) had hepatitis C, and 33 (15.9%) had a history of excess alcohol intake. Anti-delta testing was available in 69 of 116 patients with hepatitis B, and anti-HDV was positive in 13 of these patients (13/69, 18.8%). Of the 33 patients with a history of heavy alcohol intake, 18 had concomitant chronic viral hepatitis infection, and alcohol alone was the etiology of hepatocellular carcinoma in only 15 cases (7.2%). The distribution of etiologic factors was not homogenous in different geographical regions in Turkey. In central, south, and southeastern Turkey, the predominant etiology of hepatocellular carcinoma was hepatitis B, whereas in western Turkey the impact of hepatitis B, hepatitis C, and alcohol was similar. This study indicates that hepatitis B virus infection is the leading cause of hepatocellular carcinoma in Turkey, followed by hepatitis C infection and alcoholic liver disease.

Nested restriction site-specific PCR to detect and type hepatitis C virus (HCV): a rapid method to distinguish HCV subtype 1b from other genotypes

Genotypic differentiation of hepatitis C virus (HCV) has become an integral part of clinical management and epidemiologic studies of hepatitis C infections. Thus, it is extremely important in areas such as the Czech Republic, where current instrumentation and kits for assessing HCV infection are too costly for widespread use. We describe a new and relatively inexpensive method called nested restriction site-specific PCR (RSS-PCR) that generates a "fingerprint" pattern to represent an HCV genotype without the use of restriction endonucleases and that specifically differentiates HCV genotype 1b from the other HCV genotypes. The RSS-PCR method was applied directly to serum samples from patients with hepatitis C from the Czech Republic and from patients with known HCV genotypes from the United States. The method was validated by comparison of the subtype determined by RSS-PCR to the subtype determined from analysis of the 5' noncoding region (NC) or the nonstructural protein gene (NS5b) nucleotide sequence of HCV in these clinical samples. From 75 Czech samples containing HCV RNA, three distinct RSS-PCR patterns were observed; 54 were predicted to contain subtype 1b, 19 were predicted to contain subtype 1a, and 2 were predicted to contain subtype 3a. Among 54 samples predicted to contain HCV genotype 1b, all were confirmed by their 5' NC or NS5b sequences to be subtype 1b. Thus, both the sensitivity and specificity of the RSS-PCR test for the differentiation of HCV subtype 1b from the others were 100%. While the assay described here was designed to specifically differentiate HCV subtype 1b from the other HCV genotypes, the RSS-PCR method can be modified to differentiate any HCV genotype or subtype of interest. Its simplicity and speed may provide new opportunities to study the epidemiology of HCV infections and the relationship between HCV genotypes and clinical outcome by more laboratories throughout the world.

Amantadine monotherapy of chronic hepatitis C patients infected with genotype lb

We aimed to test the efficacy of amantadine in chronic hepatitis C (CHC) patients infected with genotype b. Twenty patients completed treatment with amantadine HCl, 100 mg b.i.d., for 6 months. Non-sustained biochemical improvement was observed without loss of HCV-RNA. We conclude that amantadine monotherapy is not effective in CHC.

Genomic and phylogenetic analysis of hepatitis C virus isolates from argentine patients: a six-year retrospective study

Typing of hepatitis C virus (HCV) isolates from Argentine patients was performed by using different methodologies in a population of 243 patients. HCV subtype was assigned based upon restriction fragment length polymorphism (RFLP). HCV RNA genomes obtained from serum samples were classified as belonging to clade 1 (53.5%), 2 (23. 0%), or 3 (8.6%); 14.8% of samples showed HCV mixed infections, more frequently implying different subtypes within the same clade. In addition to RFLP typing, phylogenetic relatedness among sequences from both 5' untranslated region (n = 50) and nonstructural 5B coding region (n = 15) was established.

Poor response to interferon treatment for chronic hepatitis C in human immunodeficiency virus-infected haemophiliacs

We performed a pilot study to evaluate the factors associated with response to interferon (IFN) therapy for chronic hepatitis C (CHC) with human immunodeficiency virus (HIV) coinfected haemophiliacs. Seven haemophiliacs, coinfected with HIV and hepatitis C virus (HCV), received 9 mega-units (MU) of natural IFN-alpha daily during the first 2 weeks and then three times a week for 22 weeks, all injected subcutaneously. Six patients were receiving zidovudine (AZT) 600 mg day-1 and didanosine (ddI) 200 mg day(-1) during IFN therapy. This treatment was safe and well tolerated. Four patients had no detectable serum HCV-RNA at the end of therapy, but long-term, none of the seven patients achieved a sustained response, i.e. undetectable serum HCV-RNA with persistently normal serum alanine aminotransferase (ALT) 6 months after therapy. IFN did not affect CD4-positive cell counts. Most of our patients had high HCV-RNA loads and/or low CD4 counts, both unfavourable markers for IFN therapy. In conclusion, IFN therapy did not eradicate HCV from haemophiliacs coinfected with HIV.

Hepatitis C virus genotyping by polymerase chain reaction and DNA enzyme immunoassay among Saudi patients in the Western Province, Saudi Arabia

BACKGROUND

The distribution of hepatitis C virus (HCV) genotypes in the Western Province of Saudi Arabia is unknown. The purpose of our study was to determine the prevalent HCV genotypes among HCV seropositive Saudi patients in the Western Province, and to study the relationship between types/subtypes, clinical status and liver histology.

PATIENTS AND METHODS

Serum samples were collected from 140 consecutive patients attending the Hepatology Clinic with varying grades of liver diseases, high alanine transferase (ALT) for >6 months, positive HCV, qualitative PCR, and who had had liver biopsy. HCV genotyping was determined on patients who had tested positive by both HCV enzyme immunoassay (EIA) and recombinant immunoblot assay (RIBA).

RESULTS

Of the 140 patients, 97 (69.2%) had genotype 4, 18 (12.8%) had genotype 1a, and 16 (11.4%) had genotype 1b. Genotypes 2b and 5 were found in two patients (1.4%) each, while 5 patients (3.6%) had mixed infections with genotypes 4 and 5. Of the 97 patients infected with genotype 4, 84 (86.6%) had chronic active hepatitis (CAH), two (2.1%) had CAH with active cirrhosis, 9 (9.3%) had cirrhosis and two (2.1%) had normal liver histology (NLH).

CONCLUSION

The most prevalent HCV genotype in the Western Province of Saudi Arabia was genotype 4 (69.2%). Genotype 1b was encountered in 16 (11.4%) patients. For the first time, genotype 5 was identified in the Western Province of Saudi Arabia. Genotypes 1b and 4 were associated with different histological grades of liver disease.

Clinical significance of hepatitis C virus genotypes

On the basis of phylogenetic analysis of nucleotide sequences, multiple genotypes and subtypes of hepatitis C virus (HCV) have been identified. Characterization of these genetic groups is likely to facilitate and contribute to the development of an effective vaccine against infection with HCV. Differences among HCV genotypes in geographic distributions have provided investigators with an epidemiologic marker that can be used to trace the source of HCV infection in a given population. HCV genotype 1 may represent a more aggressive strain and one that is less likely to respond to interferon treatment than HCV genotype 2 or 3. However, these observations require confirmation before HCV genotyping can be used in clinical settings.

Clinical significance of hepatitis C virus genotypes

On the basis of phylogenetic analysis of nucleotide sequences, multiple genotypes and subtypes of hepatitis C virus (HCV) have been identified. Characterization of these genetic groups is likely to facilitate and contribute to the development of an effective vaccine against infection with HCV. Differences among HCV genotypes in geographic distributions have provided investigators with an epidemiologic marker that can be used to trace the source of HCV infection in a given population. HCV genotype 1 may represent a more aggressive strain and one that is less likely to respond to interferon treatment than HCV genotype 2 or 3. However, these observations require confirmation before HCV genotyping can be used in clinical settings.

Diagnostic tests for hepatitis C

Two categories of virological assays are in practice used for the diagnosis and management of hepatitis C virus (HCV) infection, including serological and molecular biology-based assays. Serological assays include: screening tests based on enzyme immunoassays (EIAs); supplemental "analytical" assays based on immunoblot testing; and serological assays detecting genotype-specific antibodies for the serological determination of HCV genotype, so-called "serotyping" assays. Molecular assays include: qualitative assays, detecting HCV RNA in body fluids; quantitative assays measuring HCV viral load, a parameter that estimates the level of HCV replication in the liver; and tests analyzing the sequence of HCV genomes (genotyping assays).

Comparison of characteristics between patients with GB virus C/hepatitis G virus (GBV-C/HGV) RNA and those with GBV-C/HGV E2-antibody in patients with hemophilia

We compared characteristics of patients with GB virus C/hepatitis G virus (GBV-C/HGV) RNA to those of patients with GBV-C/HGV E2-antibody. GBV-C/HGV RNA and GBV-C/HGV antibody were assayed in 83 persons with hemophilia using a reverse transcription-polymerase chain reaction and an enzyme-linked immunosorbent assay, respectively. GBV-C/HGV RNA was detected in 19 (22.9%) patients and GBV-C/HGV antibody was detected in 17 (20.5%). The background characteristics between the patient groups did not differ with respect to age, severity of hemophilia based on the frequency of use of blood product, and both the initial age at the first use and years since the first use of blood products. There were no differences in coinfection with hepatitis C virus (HCV) and/or human immunodeficiency virus, except that infection with HCV subtype 1a was more prevalent in patients with GBV-C/HGV RNA (P = 0.0229). Human lymphocyte antigen (HLA) typing was conducted in 18 patients with GBV-C/HGV RNA and 15 patients with GBV-C/HGV E2-antibody; 13 of the patients with GBV-C/HGV antibody had either HLA DQ7, DR15, or DR8, whereas only 4 of the patients with GBV-C/HGV RNA did (P < 0. 001). It is concluded that the presumed age at the time of GBV-C/HGV infection, the frequency of exposure to GBV-C/HGV, and the time since the GBV-C/HGV infection were not associated with recovery from infection with GBV-C/HGV. Coinfection with HCV subtype 1a may be related to persistent GBV-C/HGV viremia, whereas HLA DQ7, DR15, or DR8 may be related to the clearance of GBV-C/HGV after infection.

Interferon treatment of two patients with quadruple infection with hepatitis C virus (HCV), human immunodeficiency virus (HIV), hepatitis G virus (HGV), and TT virus (TTV)

We administered interferon (IFN) to two patients who had quadruple infection with hepatitis C virus (HCV), human immunodeficiency virus (HIV), hepatitis G virus (HGV), and TT virus (TTV), a recently isolated novel DNA virus. Nine mega-units of natural alpha-IFN were administered daily during the first two weeks and thrice weekly during the following 22 weeks (total dose, 720 mega-units). In both cases, serum alanine aminotransferase (ALT) levels decreased during IFN administration but increased thereafter. The concentrations of HCV, HIV, HGV, and TTV declined with the administration of IFN. However, the concentrations of these 4 viruses increased after the cessation of IFN with the except of TTV in patient 2 which disappeared during treatment and did not subsequently reappear. IFN reduced the concentrations of 4 viruses, in an apparently independent manner.

Why is the interferon sensitivity-determining region (ISDR) system useful in Japan?

BACKGROUND/AIMS

The amino acid sequence of NS5A2209-2248, named the "interferon sensitivity-determining region" (ISDR), has been reported to correlate with responsiveness of interferon (IFN) therapy to patients with the hepatitis C virus (HCV) genotype-1b, by several Japanese authors. However, European authors have failed to find this phenomenon, suggesting a difference in HCV-1b isolates between Japan and Europe.

METHODS

We compared the HCV-1b nucleotide sequences of our Japanese patients and those of other countries quoted from GenBank, using the envelope 1 sequence.

RESULTS

A phylogenetic tree analysis revealed two characteristic groups from a geographical viewpoint: one group (NJ group) consists of almost entirely non-Japanese isolates, and the other (J group) of almost entirely Japanese isolates. The isolates other than the NJ and J groups are characterized by their specific nucleotide residue, constructing an individual group (W group). Japanese HCV-1b isolates consist of the J group and W group (approximately 40% and 60%, respectively). Comparative study between the two groups in Japanese patients treated with IFN revealed a strong correlation between ISDR type and IFN responsiveness only in the J group, but not in the W group.

CONCLUSIONS

These observations convinced us that the existence of the Japan-specific J group is one reason why the ISDR system is useful only in Japan.

Infection with TT virus, a novel transfusion-transmissible DNA virus, in haemophiliacs and in blood products

We evaluated the characteristics and rate of infection with TT virus (TTV), a novel DNA virus, in Japanese haemophiliacs. TTV DNA was measured in 60 haemophiliacs by semi-nested polymerase chain reaction. Co-infection with hepatitis C virus (HCV), hepatitis G virus (HGV) and human immunodeficiency virus (HIV) was also evaluated. In addition, the rate of detection of TTV DNA in blood products was evaluated. TTV DNA was detected in 35/60 haemophiliacs (58.3%). There were no differences in the backgrounds or characteristics between haemophiliacs with and without TTV infection, except for higher levels of IgG and IgM in patients with TTV infection. In patients infected with TTV of types other than type 1, which are rarely detected in Japan, the rate of co-infection with HCV of imported types was high; TTV of types other than type 1 in Japanese haemophiliacs were probably transmitted by imported blood products. TTV DNA was detected in over half of the blood products tested, but TTV DNA concentrations in these products were lower than in the serum of haemophiliacs.

Inefficient recognition of autologous viral sequences by intrahepatic hepatitis C virus-specific cytotoxic T lymphocytes in chronically infected subjects

Cytotoxic T lymphocytes (CTL) capable of recognizing prototype hepatitis C virus (HCV) sequences have been shown to localize to the liver in chronically infected individuals, where they are thought to influence hepatic inflammation and viral replication. We isolated three intrahepatic CD8(+) CTL clones from two individuals with chronic HCV infection and compared the recognition of prototype and autologous HCV sequences. These CTL recognized epitopes within the NS2 (amino acids 957-964) or NS3 (amino acids 1402-1410 and 1406-1415) proteins in the context of HLA B37, B8, or A2.1, respectively. The corresponding predominant autologous HCV sequences (SDWAANGL, ELAAKLVGL, and ALRGMGVNAV, respectively) differed from the HCV-1 sequences used for screening (RDWAHNGL, ELAAKLVAL, and KLVALGINAV, respectively) at one to five residues. For each CTL clone, recognition of the autologous HCV sequence required significantly higher peptide concentrations than did recognition of the HCV-1 sequence; for two of the clones, recognition was minimal or absent at peptide concentrations as high as 25 microM. These data show that intrahepatic HCV-specific CD8(+) CTL clones can be relatively inefficient at recognizing autologous viral epitopes. Inefficient recognition of autologous HCV sequences should influence the interpretation of data generated using prototype HCV sequences and might have implications in vivo.

Genotyping HCV isolates from Italy by type-specific PCR assay in the core region

A revision of the polymerase chain reaction (PCR) core procedure was performed for genotyping hepatitis C virus (HCV) in 139 patients from Italy. This procedure, developed prior to the identification of new genotypes, may be inadequate in several geographical areas. We proposed a new typing mixture in which primers for types 2c and 4, that are reported to be circulating in Italy, were added and a primer for type 2b was substituted. Using the modified procedure, 139 HCV-positive patients were analysed. The HCV genotype was identified in 96.4% of the cases. We observed double infections and unclassified genotypes in 5 (3.6%) and 5 (3.6%) patients, respectively. The classification of isolates into genotypes and subtypes 2b, 2c and 4 was confirmed by sequence analysis. Furthermore, the efficiency and accuracy of the modified core procedure were evaluated by parallel testing of 107 out of 139 samples using the line probe assay, and demonstrated a 98.9% degree of concordance. The results demonstrated the specificity of the selected primers for type 2c, 2b and 4 and confirmed the circulation of types 2c and 4 in Italy. In conclusion, the proposed modified PCR procedure is the only primer-specific PCR genotyping method available for identification of the 2c and 4 genotypes reported to be circulated in Italy and other European countries.

Assessment and treatment of liver disease in Japanese haemophilia patients

We studied the prevalence of the hepatitis C virus (HCV), human immunodeficiency virus (HIV) and GB virus C or hepatitis G virus (GBV-C/HGV), and characteristics of infections in Japanese haemophilia patients. Haemophilia patients were highly infected with HCV (88.2%) because of frequent use of unheated blood concentrates. Analysis for HCV genotypes revealed characteristics of HCV infection in haemophilia patients. Japanese haemophilia patients were highly infected with rare genotypes in Japan: genotype 1a (26.5%), genotype 3 (14.5%) and genotype 4 (2.4%). HIV infection was observed in 32.3% of haemophilia patients. HCV quasispecies (clones) and direct sequencing were investigated in patients with a single HCV genotype in the hypervariable region 1 of HCV, which resulted in a high degree of diversity. This indicates that even a single genotype of HCV might have multiple origins. GBV-C/HGV infection was noted in 20.9% of Japanese haemophilia patients. Over 40 haemophilia patients with chronic hepatitis C have been treated with interferon alpha for 6 months at total doses of 480-720 million units. About 38% showed clearance of HCV RNA from serum. Six patients with HIV infection were included in the study and they did not show eradication of HCV from the serum. This might derive from that they had high serum HCV RNA titers and genotype 1a or 1b. Histologic assessment was performed in 36 haemophilia patients with HCV. No case showed a histologically normal liver. Hepatic fibrosis in the biopsy specimens was classified into five stages of fibrosis and compared with serum hepatic fibrosis markers. Serum hyaluronic acid mostly correlated with hepatic fibrosis (r = 0.78, P < 0.0001) followed by type IV collagen (r = 0.38, P < 0.05). This suggests that estimation of serum fibrosis markers might be substituted for liver biopsy in haemophilia patients.

Molecular typing of enteroviruses: current status and future requirements. The European Union Concerted Action on Virus Meningitis and Encephalitis

Human enteroviruses have traditionally been typed according to neutralization serotype. This procedure is limited by the difficulty in culturing some enteroviruses, the availability of antisera for serotyping, and the cost and technical complexity of serotyping procedures. Furthermore, the impact of information derived from enterovirus serotyping is generally perceived to be low. Enteroviruses are now increasingly being detected by PCR rather than by culture. Classical typing methods will therefore no longer be possible in most instances. An alternative means of enterovirus typing, employing PCR in conjunction with molecular genetic techniques such as nucleotide sequencing or nucleic acid hybridization, would complement molecular diagnosis, may overcome some of the problems associated with serotyping, and would provide additional information regarding the epidemiology and biological properties of enteroviruses. We argue the case for developing a molecular typing system, discuss the genetic basis of such a system, review the literature describing attempts to identify or classify enteroviruses by molecular methods, and suggest ways in which the goal of molecular typing may be realized.

A novel DNA virus (TTV) associated with elevated transaminase levels in posttransfusion hepatitis of unknown etiology

By means of representational difference analysis, a viral clone (N22) of 500 nucleotides was isolated from serum of a patient (TT) with posttransfusion hepatitis of unknown etiology. The N22 clone showed a poor homology to any reported sequences. Oligonucleotide primers were deduced from the N22 sequence for detecting it by polymerase chain reaction. N22 sequence in serum banded at a sucrose density of 1.26 g/cm3, indicating its association with a viral particle which was designated TT virus (TTV). Since nucleic acids of TTV were sensitive to DNase I, it would be a DNA virus. TTV DNA was detected in sera from three of the five patients with posttransfusion non-A to G hepatitis, including the index case (TT). TTV DNA titers closely correlated with aminotransferase levels in the three patients. These results indicate that TTV would be a novel DNA virus with a possible capacity to induce posttransfusion non-A to G hepatitis.