A comparative review of HLA associations with hepatitis B and C viral infections across global populations

Hepatitis B (HBV) and hepatitis C (HCV) viral infection or co-infection leads to risk of development of chronic infection, cirrhosis and hepatocellular carcinoma (HCC). Immigration and globalization have added to the challenges of public health concerns regarding chronic HBV and HCV infections worldwide. The aim of this study is to review existing global literature across ethnic populations on HBV and HCV related human leukocyte antigen (HLA) associations in relation to susceptibility, viral persistence and treatment. Extensive literature search was conducted to explore the HLA associations in HBV and HCV infections reported across global populations over the past decade to understand the knowledge status, weaknesses and strengths of this information in different ethnic populations. HLA DR13 is consistently associated with HBV clearance globally. HLADRB1*11/*12 alleles and DQB1*0301 are associated with HBV persistence but with HCV clearance worldwide. Consistent association of DRB1*03 and *07 is observed with HCV susceptibility and non-responsiveness to HBV vaccination across the population. HLA DR13 is protective for vertical HBV and HCV transmission in Chinese and Italian neonates, but different alleles are associated with their susceptibility in these populations. HLA class Ⅰmolecule interactions with Killer cell immunoglobulin like receptors (KIR) of natural killer (NK) cells modulate HCV infection outcome via regulating immune regulatory cells and molecules. HLA associations with HBV vaccination, interferon therapy in HBV and HCV, and with extra hepatic manifestations of viral hepatitis are also discussed. Systematic studies in compliance with global regulatory standards are required to identify the HLA specific viral epitope, stage specific T cell populations interacting with different HLA alleles during disease progression and viral clearance of chronic HBV or HCV infections among different ethnic populations. These studies would facilitate stage specific therapeutic strategies for clearance of HBV and HCV infections or co-infections across global populations and aid in identification of HBV-HCV combined vaccine. HLA associations of chronic HBV or HCV development with confounding host factors including alcohol, drug abuse, insulin resistance, age and gender are lacking and warrant detailed investigation across global populations.     

Evidence for human leukocyte antigen heterozygote advantage against hepatitis C virus infection

Outcomes of infection with hepatitis C virus (HCV) vary widely, from asymptomatic clearance to chronic infection, leading to complications that include fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure. Previous studies have reported statistical associations between human leukocyte antigen (HLA) heterozygosity and favorable outcomes of infection with either hepatitis B virus (HBV) or human immunodeficiency virus (HIV) (the "heterozygote advantage"). To investigate whether HLA zygosity is associated with outcome of HCV infection, we used data from the United States Organ Procurement and Transplantation Network database of 52,435 liver transplant recipients from 1995 through 2005. Of these, 30,397 were excluded for lack of HLA data, retransplantation, known HIV infection, or insufficient information regarding HBV infection. The remaining cases were analyzed for associations between HCV infection and HLA zygosity with 1-sided Fisher's exact tests. Results show significantly lower proportions of HLA-DRB1 heterozygosity among HCV-infected than uninfected cases. The differences were more pronounced with alleles represented as functional supertypes (P = 1.05 x 10(-6)) than as low-resolution genotypes (P = 1.99 x 10(-3)). No significant associations between zygosity and HCV infection were found for other HLA loci. Conclusion: These findings constitute evidence for an advantage among carriers of different supertype HLA-DRB1 alleles against HCV infection progression to end-stage liver disease in a large-scale, long-term study population. Considering HLA polymorphism in terms of supertype diversity is recommended in strategies to design association studies for robust results across populations and in trials to improve treatment options for patients with chronic viral infection. Access to deidentified clinical information relating genetic variation to viral infection improves understanding of variation in infection outcomes and might help to personalize medicine with treatment options informed in part by human genetic variation.     

Impact of acute hepatitis B virus superinfection on chronic hepatitis C virus infection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) dual infection is not uncommon, but the impact of acute HBV superinfection in patients with chronic HCV infection is still unknown. Two patients with well documented chronic HCV infection were hospitalized for acute hepatitis, which was serologically confirmed to be acute HBV superinfection. One patient who was seropositive for both HBV-DNA and HCV-RNA upon admission died of hepatic failure. The other became seronegative for HCV-RNA and recovered with alanine aminotransferase normalization, seroclearance of HBsAg, and antibodies to HCV. These findings confirm that acute superinfection in patients with chronic hepatitis may increase the risk for severe hepatitis, and suggest that HBV as the newcomer may suppress the pre-existing HCV. Together with the earlier observation that acute HCV superinfection suppresses pre-existing HBV, it seems that the timing or sequence of infection is a factor influencing the outcome of viral interactions.     

IL28B polymorphism does not determine outcomes of hepatitis B virus or HIV infection

An IL28B haplotype strongly determines the outcome of natural and interferon-α treated hepatitis C virus (HCV) infection. To assess whether the polymorphism marking the haplotype (rs12979860) also affects other interferon-α responsive chronic viral illnesses, namely hepatitis B virus (HBV) and human immunodeficiency virus (HIV) type 1 infections, we genotyped 226 individuals with HBV persistence, 384 with HBV recovery, and 2548 with or at high risk for HIV infection. The C/C genotype of rs12979860 was not associated with HBV recovery (odds ratio, 0.99), resistance to HIV infection (odds ratio, 0.97), or HIV disease progression (P > .05). This IL28B single-nucleotide polymorphism affects the immune response to HCV but not to HBV or HIV.     

丙型肝炎病毒感染个体的准种源于感染过程中的病毒核酸突变

目的研究丙型肝炎病毒(HCV)准种特性与感染慢性化的关系,以及个体准种特性的来源形式。方法收集HCVRNA阳性的10例急性丙肝、20例慢性丙型肝炎(丙肝)和11例肝细胞癌(HCC)患者,采用单链构型多态性分析(SSCP)方法进行HCV准种检测。结果急性丙肝、慢性丙肝和HCC患者中,SSCP电泳条带数分别为2．7±1．16、4．8±1．68和5．2±2．85。慢性丙肝和HCC的条带数显著高于急性丙肝(P＜0．05)。进行DNA序列分析研究发现,准种高变区间的变异性显著低于本地株间和异地株间的变异性(P＜0．01)。结论SSCP是检测准种相对简便而有效的方法。HCV准种特性与其感染慢性化相关。HCV感染个体准种的来源主要为感染过程中的核酸突变。     

Significance of hepatitis virus infection in the oncogenic initiation of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the most common causes of cancer-related death worldwide. Chronic infection of hepatitis B virus(HBV) and/or hepatitis C virus(HCV) is a major risk factor in the development of the HCC, independently from excessive alcohol abuse and metabolic disease. Since the biology of HBV and HCV is different, their oncogenic effect may go through different mechanisms, direct and/or indirect. Viral hepatitis infection is associated with cellular inflammation, oxidative stress, DNA damage, that may lead to subsequent hepatic injuries such as chronic hepatitis, fibrosis, cirrhosis, and finally HCC. Direct oncogenic properties of these viruses are related with their genotypic characteristics and the ability of viral proteins to interact with host proteins, thus altering the molecular pathways balance of the cells. In addition, the integration of HBV DNA, especially the gene S and X, in a particular site of the host genome can disrupt chromosomal stability and may activate various oncogenic mechanisms, including those in hematopoietic cells. Recently, several studies also had demonstrated that viral hepatitis could trigger the population of hepatic cancer stem cells. This review summarize available pre-clinical and clinical data in literature regarding oncogenic properties of HBV and HCV in the early initiation of HCC.     

Hepatitis B and hepatitis C viruses: a review of viral genomes,viral induced host immune responses,genotypic distributions and worldwide epidemiology

Hepatitis B and hepatitis C viruses (HCV) are frequently propagating blood borne pathogens in global community. Viral hepatitis is primarily associated with severe health complications, such as liver cirrhosis, hepatocellular carcinoma, hepatic fibrosis and steatosis. A literature review was conducted on hepatitis B virus (HBV), HBV genome, genotypic distribution and global epidemiology of HBV, HCV, HCV genome, HCV and host immune responses, HCV genotypic distribution and global epidemiology. The valued information was subjected for review. HBV has strict tissue tropism to liver. The virus infecting hepatocytes produces large amount of hepatitis B surface antigen particles which lack the DNA. It has capability to integrate into host genome. It has been found that genotype C is most emerging genotype associated with more severe liver diseases (cirrhosis). The approximate prevalence rate of genotype C is 27.7% which represents a major threat to future generations. Approximately 8% of population is chronic carrier of HBV in developing countries. The chronic carrier rate of HBV is 2%-7% in Middle East, Eastern and Southern Europe, South America and Japan. Among HCV infected individuals, 15% usually have natural tendency to overcome acute viral infection, where as 85% of individuals were unable to control HCV infection. The internal ribosomal entry site contains highly conserved structures important for binding and appropriate positioning of viral genome inside the host cell. HCV infects only in 1%-10% of hepatocytes, but production of tumor necrosis factor alpha (from CD8+ cells) and interferon-gamma cause destruction of both infected cells and non-infected surrounding cells. Almost 11 genotypes and above 100 subtypes of HCV exists worldwide with different geographical distribution. Many efforts are still needed to minimize global burden of these infections. For the complete eradication of HBV (just like small pox and polio) via vaccination strategies, sincere efforts would be required from government and nongovernmental organizations.     

A Review of Hepatitis B Virus and Hepatitis C Virus Immunopathogenesis

Despite the advances in therapy, hepatitis B virus (HBV) and hepatitis C virus (HCV) still represent a significant global health burden, both as major causes of cirrhosis, hepatocellular carcinoma, and death worldwide. HBV is capable of incorporating its covalently closed circular DNA into the host cell’s hepatocyte genome, making it rather difficult to eradicate its chronic stage. Successful viral clearance depends on the complex interactions between the virus and host’s innate and adaptive immune response. One encouraging fact on hepatitis B is the development and effective distribution of the HBV vaccine. This has significantly reduced the spread of this virus. HCV is a RNA virus with high mutagenic capacity, thus enabling it to evade the immune system and have a high rate of chronic progression. High levels of HCV heterogeneity and its mutagenic capacity have made it difficult to create an effective vaccine. The recent advent of direct acting antivirals has ushered in a new era in hepatitis C therapy. Sustained virologic response is achieved with DAAs in 85–99% of cases. However, this still leads to a large population of treatment failures, so further advances in therapy are still needed. This article reviews the immunopathogenesis of HBV and HCV, their properties contributing to host immune system avoidance, chronic disease progression, vaccine efficacy and limitations, as well as treatment options and common pitfalls of said therapy.     

Occult Hepatitis B Infection and its Possible Impact on Chronic Hepatitis C Virus Infection

As a well-recognized clinical phenomenon, persistent detectable viral genome in liver or sera in the absence of other serological markers for active hepatitis B virus (HBV) replication is called occult HBV infection. The main mechanism through which occult infection occurs is not completely understood and several possible explanations, such as integration into human genome and maintenance in peripheral mononuclear cells, exist. Occult HBV infection has been reported in different populations, especially among patients with Hepatitis C (HCV) related liver disease. The probable impact of occult HBV in patients with chronic HCV infection has been previously investigated and the evidence suggests a possible correlation with lower response to anti-viral treatment, higher grades of liver histological changes, and also developing hepatocellular carcinoma. However, in the absence of conclusive results, further studies should be conducted to absolutely assess the impact of occult HBV contamination on the HCV related liver disease.     

Relationship between HLA‐DPA1 mRNA expression and susceptibility to hepatitis B

Chronic hepatitis B virus (HBV) infection is influenced by both viral and host factors. In genome‐wide association studies, the human leucocyte antigen HLA‐DPA1 and related polymorphism rs3077 were found to be associated with susceptibility to and spontaneous clearance of HBV infection. Here, we evaluated the association between HLA‐DPA1 mRNA expression and the risk of HBV infection. HLA‐DPA1 and rs3077 polymorphisms were investigated in 169 patients with chronic HBV and 217 healthy controls (HCs) from Sichuan Han blood donors using sequence‐based typing and meta‐analysis for HLA‐DPA1 alleles. HLA‐DPA1 mRNA levels were measured by real‐time polymerase chain reaction. The results showed that HLA‐DPA1 and rs3077 were associated with HBV infection in the Sichuan population. Rs3077T and DPA1*01:03 played protective roles in HBV infection, and rs3077C and DPA1*02:02 increased susceptibility to HBV infection. We found that the HLA‐DPA1 mRNA expression was decreased in the CHB group; in particular, the 3077CT, 3077TT, DPA1*01:03 and DPA1*02:01 alleles showed a significant decrease. Our results demonstrated, for the first time, that expression of HLA‐DPA1 alleles and rs3077 affected the risk of HBV infection. Genotypes with lower HLA‐DPA1 expression had a greater susceptibility to HBV infection. Thus, further independent studies are needed to strengthen the associations of these polymorphisms with susceptibility to and clearance of HBV infection in Chinese populations.     

Risks associated with hepatitis A and hepatitis B in patients with hepatitis C.

Individuals with hepatitis C virus (HCV) are at risk for acquiring hepatitis A virus (HAV) or hepatitis B virus (HBV) because of shared risk factors. A number of organizations recommend vaccination against HAV and HBV for patients with HCV. The rationale for vaccinating these patients is to prevent hepatic superinfections. Acute HAV superinfection causes more severe disease, acute hepatic failure, and higher fatality rates in patients with underlying chronic liver disease, specifically chronic HBV infection and chronic HCV infection. Available data, although limited, suggest that HBV coinfection with HAV and HCV causes more severe hepatic injury than infection with HAV or HCV alone. At standard doses, hepatitis A and hepatitis B vaccines are safe and immunogenic in patients with mild-to-moderate hepatitis C or chronic liver disease. Regardless of disease severity, vaccination should be routinely administered to patients upon diagnosis of HCV infection. Early vaccination is important because response to vaccination is reduced as liver disease progresses. Prevaccination and postvaccination serology testing is recommended in specific populations. A new combination hepatitis A and hepatitis B vaccine has been shown to be as safe and effective as monovalent hepatitis A and B vaccines and is currently under review by the United States Food and Drug Administration. A combination vaccine would offer ease of administration and convenience and could increase compliance in patients with hepatitis C or other chronic liver disease: two groups that should be more aggressively targeted by healthcare professionals.     

Host genetic factors influencing the outcome of hepatitis

A strong genetic component determining the outcome of hepatitis B virus (HBV) infection has been established through twin studies. The immunopathogenesis of HBV infection is well described and it has therefore been possible to predict some gene loci, exhibiting polymorphism, may influence the outcome of HBV infection. As expected, the immune response genes in the major histocompatibility complex (MHC) on the short arm of chromosome 6 have provided confirmed susceptibility genes. In hepatitis C virus (HCV) infection the picture is not so clear although comparison of the known immunological phenomena with those of HBV suggest that polymorphisms in the MHC may also influence disease outcome. Identification of susceptibility genes, which modify disease phenotype, may assist in predicting natural outcome of infection or response to therapy.     

Hepatitis B virus infection and alcohol consumption

Hepatocellular carcinoma(HCC) is the most common type of primary liver cancer, and the second most common cause of cancer deaths worldwide. The top three causes of HCC are hepatitis B virus(HBV),hepatitis C virus(HCV), and alcoholic liver disease. Owing to recent advances in direct-acting antiviral agents, HCV can now be eradicated in almost all patients. HBV infection and alcoholic liver disease are expected, therefore, to become the leading causes of HCC in the future. However, the association between alcohol consumption and chronic hepatitis B in the progression of liver disease is less well understood than with chronic hepatitis C. The mechanisms underlying the complex interaction between HBV and alcohol are not fully understood, and enhanced viral replication, increased oxidative stress and a weakened immune response could each play an important role in the development of HCC. It remains controversial whether HBV and alcohol synergistically increase the incidence of HCC. Herein, we review the currently available literature regarding the interaction of HBV infection and alcohol consumption on disease progression.     

Host genetic variations associated with disease progression in chronic hepatitis C virus infection

Treatment with recently developed interferon‐free oral regimens combining direct‐acting antiviral agents (DAAs) results in the elimination of hepatitis C virus (HCV) in almost all chronic hepatitis C (CHC) patients. In the era of DAAs, surveillance of hepatocellular carcinoma (HCC) after eradication of HCV by anti‐HCV therapy is particularly important. As is well known, an advanced state of hepatic fibrosis is the major risk factor for developing HCC. Therefore, an increased understanding of various factors associated with disease progression and development of HCC in CHC patients is essential for implementing personalized treatment and surveillance of disease progression and HCC. Recent genome‐wide association studies (GWAS) have identified several host genetic variants influencing treatment efficacy or clinical course in HCV infection. This review focuses on these host genetic variations recently identified, mainly by GWAS, which are associated with the clinical course of chronic HCV infection, especially disease progression and hepatocarcinogenesis.     

Severe liver disease is caused by HBV rather than HCV in children with hematological malignancies

Patients receiving chemotherapy experience exacerbations of chronic hepatitis B (HBV) or hepatitis C (HCV) viral infections. We examined the pattern of liver disease induced by these infections in 92 children and adolescents with elevated transaminases (median age: 9 years). This included 76 with hematological malignancies (55 ALL, 15 NHL and six Hodgkin's disease) and 16 with thalassemia major. Liver disease was graded: A--occasional hypertransaminemia, B--persistent hypertransaminemia, C--severe hepatitis without encephalopathy, D--fulminant hepatic failure (FHF) and death. Screening included HBsAg, anti-HCV antibody, HBV-DNA and HCV-RNA: 26 had liver biopsies. A total of 60 (79%) patients with malignancies were HBsAg and/or HBV-DNA(+)(genotype D-E) and 47 (62%) were anti-HCV and/or HCV-RNA(+); 33 were coinfected with HBV and HCV. Grade A (n=24) included 16 with HCV and 12 with HBV (six coinfected); 18 with HBV and 11 with HCV (10 coinfected) were graded B (n=22). All grade C (n=25) had HBV with 16 HCV coinfected. FHF and death occurred in five HBV-DNA(+) patients, in four within a month of i.v. methotrexate. Patterns C and D were associated with HBsAg and HBV-DNA (P=0.001 and P<0.001, respectively). In all, 70% of HBV-infected children suffered chemotherapy-associated flares. None of the thalassemics had severe hepatitis exacerbations; 94% had HCV markers with none HBV-DNA(+). One died of progressive cirrhosis. CONCLUSIONS: Children with hematological malignancies have worse liver disease when associated with chronic HBV. FHF occurred in HBsAg/HBV-DNA(+) children following i.v. methotrexate. Early recognition of hepatic dysfunction in HBV carriers is essential in order to reduce incidence of life-threatening complications.     

Natural history: The importance of viral load, liver damage and HCC

Viral hepatitis is the main cause of liver disease. Progression of viral hepatitis leading to liver cirrhosis and hepatocellular carcinoma occurs frequently in chronic HBV- and HCV-infected patients. Viral and host-related factors and modifiable and non-modifiable factors associated with advanced liver disease can be distinguished. For hepatitis B, viral factors include HBeAg status, HBV genotype, naturally occurring mutations, and viral load. The level of serum HBV DNA, reflecting the concentration of intrahepatic HBV DNA, is positively correlated with the risk for liver cirrhosis and HCC. The continued presence of intracellular hepatitis B virus and the resulting immune response might be the driving force for the progression of HBV-related liver disease and HBV reactivation. However, little is known about the natural course of intrahepatic HBV DNA, and further studies are needed. Patients with HCV and/or HDV and/or HIV coinfections are at an increased risk for an adverse outcome of their liver disease. For hepatitis C, courses of the disease are variable. Viral factors seem to be less significant for disease progression, while host-related effects play a more important role. Among these are modifiable cofactors such as hepatic steatosis and insulin resistance which lead to a more severe disease and lower response to antiviral therapy with chronic hepatitis C. The precise interactions between HCV and host metabolic factors need further elucidation, especially as the rate of metabolic diseases is on the increase.     

Serum adiponectin in chronic hepatitis C and B

Adiponectin possesses anti-inflammatory, insulin-sensitizing and anti-atherosclerotic properties. The aim of this study was to assess the levels of serum adiponectin in patients with chronic viral hepatitis C and B and correlate them with parameters exploring insulin resistance and indices of chronic liver disease. Seventy-two patients with chronic hepatitis C virus (HCV) infection and 73 patients with chronic hepatitis B virus (HBV) infection, matched for age and sex, were studied. All individuals were examined for serum concentrations of adiponectin, insulin, C-peptide and homeostasis model assessment for insulin resistance (HOMA-IR). Viral parameters and liver histology were also evaluated. Serum adiponectin levels were significantly higher in HCV compared with HBV-infected patients. Correlation analysis in the whole group demonstrated that serum adiponectin was positively correlated with aspartate aminotransferase, alkaline phosphatase, globulins, high-density lipoprotein cholesterol and staging score, while it was negatively correlated with body mass index, insulin, C-peptide and HOMA-IR. Logistic regression analysis identified type of infection (HCV vs HBV), alcohol consumption more than 25 g daily, serum total globulin and low C-peptide as significant predictive variables associated with high adiponectin levels. Higher levels of serum adiponectin in HCV compared with HBV patients could have a role in the slower disease progression of chronic HCV infection. In addition, alcohol intake more than 25 g daily seems to be a significant predictor for hyperadiponectinaemia in patients with chronic viral hepatitis C or B. Finally, in this study, a clear positive association between adiponectin and hepatic necroinflammation or staging score was not found.     

Chronic hepatitis B reactivation following infliximab therapy in Crohn's disease patients: need for primary prophylaxis

BACKGROUND: There is little information about the effect of infliximab on the clinical course of liver disease in Crohn's disease patients with concomitant hepatitis B virus (HBV) infection. Theoretically, immunosuppression induced by infliximab will facilitate viral replication which could be followed by a flare or exacerbation of disease when therapy is discontinued. There are no specific recommendations on surveillance and treatment of HBV before infliximab infusion. Two cases of severe hepatic failure related to infliximab infusions have been described in patients with rheumatic diseases. PATIENTS AND METHODS: Hepatitis markers (C and B) and liver function tests were prospectively determined to 80 Crohn's disease patients requiring infliximab infusion in three hospitals in Spain. RESULTS: Three Crohn's disease patients with chronic HBV infection were identified. Two of the three patients with chronic HBV infection suffered severe reactivation of chronic hepatitis B after withdrawal of infliximab therapy and one died. A third patient, who was treated with lamivudine at the time of infliximab therapy, had no clinical or biochemical worsening of liver disease during or after therapy. From the remaining 80 patients, six received the hepatitis B vaccine. Three patients had antibodies to both hepatitis B surface antigen (anti-HBs) and hepatitis B core protein (anti-HBc) with normal aminotransferase levels, and one patient had positive anti-hepatitis C virus (HCV) antibodies, negative HCV RNA, and normal aminotransferase levels. Except for the patients with chronic HBV infection, no significant changes in hepatic function were detected. CONCLUSIONS: Patients with Crohn's disease who are candidates for infliximab therapy should be tested for hepatitis B serological markers before treatment and considered for prophylaxis of reactivation using antiviral therapy if positive.     

肝炎病毒感染与胰岛素抵抗

肝炎病毒慢性持续感染主要是由乙型肝炎病毒(HBV)和丙型肝炎病毒(HCV)所致, 除了引起肝脏损害外, 还与一些肝外组织的损害密切相关. 近年来, 研究资料显示慢性HCV和HBV感染与糖尿病和脂肪肝等代谢性疾病的发病密切相关, 而胰岛素抵抗(IR)可能是其发病机制的中心环节. IR也是肝纤维化进展的相关因素, 并影响慢性肝炎病毒感染时抗病毒治疗的疗效. 此外, 糖尿病还可能增加肝炎病毒致癌的作用, 应该引起肝病医师的高度重视. 本文就近年来对HCV和HBV感染中IR发生机制方面的研究, IR在HCV和HBV感染相关的糖尿病和脂肪肝中的作用和影响及其对临床的指导意义作一述评.     

Occult hepatitis B virus infection is not associated with disease progression of chronic hepatitis C virus infection

AIM To clarify the prevalence of occult hepatitis B virus(HBV) infection(OBI) and the association between OBI and liver disease progression, defined as development of liver cirrhosis or hepatocellular carcinoma(HCC), worsening of Child-Pugh class, or mortality in cases of chronic hepatitis C virus(HCV) infection. METHODS This prospective cohort study enrolled 174 patients with chronic HCV infection(chronic hepatitis, n = 83; cirrhosis, n = 47; HCC, n = 44), and evaluated disease progression during a mean follow-up of 38.7 mo. OBI was defined as HBV DNA positivity in 2 or moredifferent viral genomic regions by nested polymerase chain reaction using 4 sets of primers in the S, C, P and X open reading frame of the HBV genome. RESULTS The overall OBI prevalence in chronic HCV patients at enrollment was 18.4%, with 16.9%, 25.5% and 13.6% in the chronic hepatitis C, liver cirrhosis and HCC groups, respectively(P = 0.845). During follow-up, 52 patients showed disease progression, which was independently associated with aspartate aminotransferase 40 IU/L, Child-Pugh score and sustained virologic response(SVR), but not with OBI positivity. In 136 patients who were not in the SVR state during the study period, OBI positivity was associated with neither disease progression, nor HCC development. CONCLUSION The prevalence of OBI in chronic HCV patients was 18.4%, and OBI was not associated with disease progression in South Koreans.