Rational pharmacotherapy and correction of immunity disorders in children with chronic hepatitis (clinical review)

The data on the efficacy of antivirals and their impact on the virologic and immunologic indices in HCV- and HBV-infected children are presented. The best therapeutic effect in the management of children with chronic virus hepatitis was provided by combined antiviral therapy of different action. In the treatment of babies the drugs of choice could be viferon or cycloferon, for the 2-year older children with chronic hepatitis B the combination of viferon + cycloferon should be recommended and for those with chronic hepatitis C the combination of interal + cycloferon could be used. The cycloferon combination with interferons-a makes it possible to generate the Th1 cellular immune response, to minimize the side effects of interferons and chemotherapeutics and to improve their tolerability. The complex therapy of patients with chronic hepatitis B and lambliasis, using cycloferon and macmiror, provided stable effect, less frequent relapses oflambliasis and minimum side effects of the specific therapy. The repeated isolation of lamblia within a 1-year observation period was recorded only in 16.6% of the children treated with cycloferon vs. the control (40.0%).     

Interferon-based treatment of chronic hepatitis C

The treatment of patients with chronic hepatitis C has rapidly evolved in the past 10 years centered on the use of interferon alpha 2 as an antiviral and immunomodulatory agent against hepatitis C virus. Firstly used as a monotherapy associated with a deceiving long-term efficacy, interferon alpha was then combined with ribavirin, a nucleoside analog with large antiviral properties. Combination of both drugs dramatically improved the efficacy of treatment with 50% of patients reaching a sustained viral response, characterized by the final eradication of the virus from the infected individual. Surprisingly, this synergistic effect remains greatly unexplained. The third step consisted in the use of pegylated interferon in order to adapt its pharmacokinetics and to allow a better efficacy with a more tolerable dosing schedule: once weekly subcutaneous injection instead of thrice weekly. Pegylated interferon combined with ribavirin during 24-48 weeks of treatment is the current standard of care with nearly 60% of sustained virologic response, overall. Development of new forms of interferon alpha are on the way with promising preliminary results.     

The Role of Viral Mutation in the Pathogenesis of Chronic Viral Hepatitis

The quasispecies nature of hepatitis B and C virus (HBV, HCV) plays an important role in the pathogenesis, immune escape and drug resistance during chronic infection. Although there is still a lack of effective treatment for hepatitis C, a series of nucleoside analogs (NA) have been developed for the treatment of hepatitis B. NA resistant HBV mutants can accumulate during prolonged therapy and lead to the failure of anti-HBV therapy. Switching to other sensitive NAs can inhibit the emerged resistant mutants. Therefore, understanding the evolution of viral quasispecies under drug pressure is crucial for the establishment of antiviral strategy and the monitoring of antiviral process. Immune response and escape are complicated process, during which both host and virus factors may play their roles. Further understanding of the interaction and interrelationship between host and these viruses may lead to optimized prevention, diagnosis and treatment for chronic hepatitis.     

The role of viral mutation in the pathogenesis of chronic viral hepatitis

The quasispecies nature of hepatitis B and C virus (HBV, HCV) plays an important role in the pathogenesis, immune escape and drug resistance during chronic infection. Although there is still a lack of effective treatment for hepatitis C, a series of nucleoside analogs (NA) have been developed for the treatment of hepatitis B. NA resistant HBV mutants can accumulate during prolonged therapy and lead to the failure of anti-HBV therapy. Switching to other sensitive NAs can inhibit the emerged resistant mutants. Therefore, understanding the evolution of viral quasispecies under drug pressure is crucial for the establishment of antiviral strategy and the monitoring of antiviral process. Immune response and escape are complicated process, during which both host and virus factors may play their roles. Further understanding of the interaction and interrelationship between host and these viruses may lead to optimized prevention, diagnosis and treatment for chronic hepatitis.     

慢性病毒性肝炎研究进展

近年,慢性病毒性肝炎研究领域有较大进展,慢性乙型肝炎病毒（HBV）感染,虽然有了应用广泛、历史较久、且效果较好的疫苗,但迄今仍是世界范围肝硬化和肝癌的主要诱因。传染途径可经产道、性接触和非肠道途径（包括静脉吸毒、血制品等）。成年病人有少有变慢性,但一岁以下患儿90％变成慢性肝炎。慢性肝损伤的临床表现可以是轻微的炎症重到晚期肝硬化,程度不等。α干扰素（IFNα）是治疗活动性肝炎的产宰药物,单核苷酸类药物（lamivudine和adefovir）也具有同样的疗效。晚期肝病和肝癌患者可进行移植,但异常伴发移植物的感染。乙型肝炎免疫球蛋白和新型抗病毒药物联合应用,可降低移植物感染的严重性。丙型肝炎病毒（HCV）在20世纪后期感染了大约1％的世界人口。这中RNA病毒非经口传播,绝大多数病人变成慢性肝炎,约20％逐渐演变成肝硬化或肝癌。用IFNα和病毒唑（Ribavirin）联合治疗,约40％病人的病理表现有所改善。肝移植对某些病例是适宜的,但移植物感染仍是悬而未决的问题,新发现的庚型肝炎病毒（HGV）和TT病毒目前认为并不引起严重的肝损害。     

内江地区慢性乙型肝炎患者的基因型及拉米夫定联合阿德福韦酯抗病毒治疗效果

目的 探讨内江地区慢性乙型肝炎患者的基因型及拉米夫定联合阿德福韦酯抗病毒的治疗效果。方法 将201例慢性乙型肝炎患者进行HBV基因型的测定,其中120例HBeAg（+）慢性乙型肝炎患者随机分为三组：A组、B组和C组,每组40例。A组给予拉米夫定(LAM)治疗;B组给予恩替卡韦(ETV)治疗;C组给予LAM联合阿德福韦酯(ADV)治疗,比较治疗情况。结果 201例慢性乙型肝炎患者中B型119例（59.2%）,C型68例（33.8%）,B/C混合型10例（5.0%）,未知型4例（2.0%）,各分型之间的性别、年龄差异无统计学意义（P＞0.05）。C型感染者HBeAg阳性率为86.8%,显著高于B型的51.3%（P＜0.05）。HBeAg（+）的3组患者治疗12、24和48周时,B组和C组患者的ALT复常率、HBV DNA阴转率及48周时的HBeAg血清转换率均显著高于A组（P＜0.05）;C组患者与B组比较差异无统计学意义（P＞0.05）。治疗期间均未见不良反应发生。C组患者（包括B型19例、C型21例）中B型的HBV DNA阴转率及HBeAg血清转换率显著高于C型（P＜0.05）。结论 地处西南方的内江地区慢性乙型肝炎患者主要以B型为主,C型次之,B型和C型共占93.0%,其他型别仅占较少部分。ETV方案或LAM联合ADV方案治疗HBeAg（+）慢性乙肝疗效优于LAM治疗。初始LAM联合ADV治疗基因B型HBeAg（+）慢性乙型肝炎疗效优于C型。     

Free fatty acids induce ER stress and block antiviral activity of interferon alpha against hepatitis C virus in cell culture

ABSTRACT: BACKGROUND: Hepatic steatosis is recognized as a major risk factor for liver disease progression and impaired response to interferon based therapy in chronic hepatitis C patients. The mechanism of response to interferon-alpha (IFN-alpha) therapy under the condition of hepatic steatosis is unexplored. We investigated the effect of hepatocellular steatosis on hepatitis C virus (HCV) replication and IFN-alpha antiviral response in a cell culture model. METHODS: Sub-genomic replicon (S3-GFP) and HCV infected Huh-7.5 cells were cultured with a mixture of saturated (palmitate) and unsaturated (oleate) long-chain free fatty acids (FFA). Intracytoplasmic fat accumulation in these cells was visualized by Nile red staining and electron microscopy then quantified by microfluorometry. The effect of FFA treatment on HCV replication and IFN-alpha antiviral response was measured by flow cytometric analysis, Renilla luciferase activity, and real-time RT-PCR. RESULTS: FFA treatment induced dose dependent hepatocellular steatosis and lipid droplet accumulation in the HCV replicon cells was confirmed by Nile red staining, microfluorometry, and by electron microscopy. Intracellular fat accumulation supports replication more in the persistently HCV infected culture than in the sub-genomic replicon (S3-GFP) cell line. FFA treatment also partially blocked IFN-alpha response and viral clearance by reducing the phosphorylation of Stat1 and Stat2 dependent IFN-beta promoter activation. We show that FFA treatment induces ER stress response and down regulates the IFNAR1 chain of the type I IFN receptor leading to defective Jak-Stat signaling and impaired antiviral response. CONCLUSION: These results suggest that intracellular fat accumulation in HCV cell culture induces ER stress, defective Jak-Stat signaling, and attenuates the antiviral response, thus providing an explanation to the clinical observation regarding how hepatocellular steatosis influences IFN-alpha response in chronic hepatitis C (CHC).     

Chemoimmunotherapy of chronic hepatitis B virus infection in the woodchuck model overcomes immunologic tolerance and restores T-cell responses to pre-S and S regions of the viral envelope protein

Treatment of chronic hepatitis B virus (HBV) infection could combine potent antiviral drugs and therapeutic vaccines to overcome immunological tolerance and induce the recovery phenotype to protect against disease progression. Conventional vaccination of woodchucks chronically infected with the woodchuck hepatitis virus (WHV) elicited differential T-cell response profiles depending on whether or not carriers were treated with the potent antiviral drug clevudine (CLV), which significantly reduces viral and antigen loads. The differential T-cell responses defined both CLV-dependent and CLV-independent epitopes of the pre-S and S regions of the WHV envelope protein. Only combined treatment involving CLV and conventional vaccine therapeutically restored the T-cell response profile of chronic WHV carrier woodchucks to that seen in prophylactic vaccination and in recovery from acute WHV infection. The results have implications for mechanisms of immunological tolerance operating in chronic HBV infection and suggest that such combined chemoimmunotherapy may be useful for treatment of humans with chronic HBV infection.     

Inhibition of hepatitis C virus-like particle binding to target cells by antiviral antibodies in acute and chronic hepatitis C

Hepatitis C virus (HCV) is a leading cause of chronic viral hepatitis worldwide. The study of antibody-mediated virus neutralization has been hampered by the lack of an efficient and high-throughput cell culture system for the study of virus neutralization. The HCV structural proteins have been shown to assemble into noninfectious HCV-like particles (HCV-LPs). Similar to serum-derived virions, HCV-LPs bind and enter human hepatocytes and hepatoma cell lines. In this study, we developed an HCV-LP-based model system for a systematic functional analysis of antiviral antibodies from patients with acute or chronic hepatitis C. We demonstrate that cellular HCV-LP binding was specifically inhibited by antiviral antibodies from patients with acute or chronic hepatitis C in a dose-dependent manner. Using a library of homologous overlapping envelope peptides covering the entire HCV envelope, we identified an epitope in the N-terminal E2 region (SQKIQLVNTNGSWHI; amino acid positions 408 to 422) as one target of human antiviral antibodies inhibiting cellular particle binding. Using a large panel of serum samples from patients with acute and chronic hepatitis C, we demonstrated that the presence of antibodies with inhibition of binding activity was not associated with viral clearance. In conclusion, antibody-mediated inhibition of cellular HCV-LP binding represents a convenient system for the functional characterization of human anti-HCV antibodies, allowing the mapping of envelope neutralization epitopes targeted by naturally occurring antiviral antibodies.     

Occult HBV infection and suppression of HCV replication in the early phase of combination therapy for chronic hepatitis C

BACKGROUND: Occult HBV infection in subjects with chronic hepatitis C is related to more severe disease outcome. It has been suggested that it might reduce sensitivity to antiviral treatment. AIMS: To assess in HBsAg negative subjects with chronic hepatitis C any effect of the presence of HBV genomes in the liver on the early kinetics of HCV-RNA under PEG-IFN plus ribavirin. PATIENTS AND METHODS: Twenty-two anti-HCV and HCV-RNA positive subjects, with biopsy-proven chronic hepatitis C (M/F 15/7; 50 +/- 8.6 years, 16 genotype 1b) were given PEG-IFN alpha 2b 1.0 microg qw plus ribavirin (800 to 1,200 mg daily according to body weight) for an intended 52 week period. Early virological response was assessed over the first 4 weeks of therapy by quantifying HCV-RNA. Occult HBV infection was assessed by testing for HBV-DNA in the liver before therapy. RESULTS: HBV genomes were found in the liver of 7 of 22 (31.4%) patients, unrelated to anti-HBc status. Kinetics of HCV-RNA during the first 4 weeks of antiviral treatment was unaffected by occult HBV infection, both in terms of absolute reduction of viral load and of number of cases with a reduction of > or = 2 log10 on treatment. CONCLUSIONS: Occult HBV infection does not affect the early phase of response to combination therapy. Further follow-up of patients into the maintenance phase of antiviral treatment and after stopping it will clarify if and when occult HBV has a role in reducing sustained virological response.     

Subversion of innate host antiviral strategies by the hepatitis C virus

Since its discovery in 1989, Hepatitis C Virus (HCV) has been recognized as a major cause of chronic hepatitis, end-stage cirrhosis and hepatocellular carcinoma affecting world wide more than 210 million people. The fact that 80% of newly infected patients fail to control infection, the slow development of overt disease and immune-response as well as the unsatisfying results of current IFN/ribavirin combination therapy suggests that the hepatitis C virus developed powerful strategies to evade and to antagonize the immune response of the host and to resist the antiviral actions of interferons. During the last 10 years several viral strategies have been uncovered for control and evasion from cellular antiviral host response initiated by the pathogen-associated molecular pattern recognizing receptors RIG1 and TLR3 and mediated by the release of type I interferon and subsequent induction of interferon stimulated genes. This review highlights recent results providing an idea of how the hepatitis C virus interferes with the different steps of initial antiviral host-response and establishes persistent infection.     

New therapeutic vaccination strategies for the treatment of chronic hepatitis B

Chronic hepatitis B virus (CHB) is currently treated with either interferon-based or nucleot(s)ide-based antiviral therapies. However, treatment with pegylated interferon alpha results in a durable antiviral response in only about 30% patients and is associated with side effects. Most patients receiving nucleot(s)ide analogue treatment do not establish long-term, durable control of infection and have rebounding viremia after cessation of therapy. Thus, novel therapy strategies are necessary to achieve the induction of potent and durable antiviral immune responses of the patients which can maintain long-term control of viral replication. Therapeutic vaccination of HBV carriers is a promising strategy for the control of hepatitis B. Here the authors review new therapeutic vaccination strategies to treat chronic hepatitis B which may be introduced for patient treatment in the future.     

Natural history and treatment of hepatitis B virus and hepatitis C virus coinfection

Hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is not uncommon as a result of similar routes of infection. Patients who are coinfected represent a unique group with diverse serologic profiles. Combined chronic hepatitis B and C leads to more severe liver disease and an increased risk of hepatocellular carcinoma. Furthermore, coinfected patients represent a treatment challenge. No standard recommendations exist for treatment of viral hepatitis due to dual HBV/HCV infection, and therefore treatment must be individualized based on patient variables such as serologic and virologic profiles, patient's prior exposure to antiviral treatment, and the presence of other parenterally transmitted viruses such as hepatitis D virus and human immunodeficiency virus. The natural history and treatment of patients with HBV and HCV coinfection is reviewed.     

Level of serum tumor necrosis factor-alpha and the degree of liver fibrosis in children with chronic viral hepatitis B,C and B+C,treated with interferon-alpha

Children with chronic virus hepatitis B and C, as well as combined chronic virus hepatitis B + C, were found to have a higher level of tumor necrosis factor-alpha (TNF-alpha) in their serum than healthy children. Complete clinical and virological response to treatment with interferon-alpha is accompanied by a decreased inflammation and fibrosis of the liver, as well as by a decreased level of TNF-alpha, in comparison with nonresponsive patients. Positive correlation between the level of TNF-alpha and the degree of liver fibrosis in sick children was noted.     

阿德福韦酯抗病毒治疗1a后乙肝病毒基因型变化情况的观察

观察阿德福韦酯抗病毒治疗1 a后慢性乙肝患者体内HBV基因型变化情况.随机选择152例慢性乙肝患者作为研究对象,其中52例患者作为抗病毒治疗组,口服阿德福韦酯进行抗病毒治疗,另外100例患者作为对照组,口服护肝片进行护肝治疗,2组病人治疗周期均为1 a,分别在用药后第3、6、12个月进行随访,随访内容包括患者的依从性和不良反应、HBeAg/HBeAb、肝功能、HBV DNA定量检测,并采用多对型特异性引物巢武PCR基因分型技术动态监测治疗期间HBV基因型的变化情况.治疗1 a后,抗病毒治疗组中有1例患者体内HBV基因型发生改变,由治疗前的B型变为B/C混合型,并且病情出现反弹和加重.对照组未发现HBV基因型改变.2组HBV基因型变化率(1.9％和0％)之间没有显著性差异(P＞0.05).慢性乙肝患者体内HBV基因型可发生改变,而且1 a内即可发生,抗病毒治疗可能是促进HBV基因型改变的相关因素.HBV基因型转变可导致患者病情反弹和加重.     

A case of hepatitis B reactivation due to the hepatitis B virus escape mutant in a patient undergoing chemotherapy

A 62-year-old man had chronic hepatitis B virus (HBV) infection and was diagnosed with liver cirrhosis. At the time of diagnosis the patient’s virologic markers were positive for hepatitis B surface antigen (HBsAg), antibody to hepatitis B e antigen (anti-HBe) and antibody to hepatitis B core antigen (anti-HBc), while antibody to hepatitis B surface antigen (anti-HBs) and HBV DNA were negative. Later the patient received chemotherapy for malignancy. However, this was interrupted due to elevated liver enzymes. At the same time HBV DNA became positive. Lamivudine (LMV) therapy was administered immediately. However, the levels of serum aminotransferase and total bilirubin (TB) were still rising. Finally the patient died of fulminant hepatic failure. A sequence revealed HBV genotype C (HBsAg subtype adw) with immune escape mutations, F8L, S34L, F41S, G44V, F93C, V96G, L110I, C149Y and F161Y. The high morbidity and mortality of this complication is one of the major obstacles to completing the standard treatment for malignancy in HBV carriers. Therefore, the relative risk of antiviral prophylactic failure should be further assessed and the optimal strategy for antiviral prophylaxis in HBsAg-positive patients with oncologic and hematologic malignancies undergoing chemotherapy should be revised.     

Hepatitis B Virus: From Diagnosis to Treatment

Hepatitis B infection is still a global concern progressing as acute-chronic hepatitis, severe liver failure, and death. The infection is most widely transmitted from the infected mother to a child, with infected blood and body fluids. Pregnant women, adolescents, and all adults at high risk of chronic infection are recommended to be screened for hepatitis B infection. The initial analysis includes serological tests that allow differentiation of acute and chronic hepatitis. Molecular assays performed provide detection and quantification of viral DNA, genotyping, drug resistance, and precore/core mutation analysis to confirm infection and monitor disease progression in chronic hepatitis B patients. All patients with chronic hepatitis B should be treated with antiviral medications and regularly monitored for efficient treatment. The current treatment is based on nucleos(t)ide analogs and pegylated interferons that save lives by decreasing liver cancer death, liver transplant, slow or reverse the progression of liver disease as well as the virus infectivity.Key words: hepatitis B virus (HBV), serology, nucleic acid testing, antiviral treatment     

Interrelation between the activity of hepatitis, liver fibrosis and immune status in children with chronic hepatitis B and C

The lesion of the liver in viral hepatitis was found to depend on the state of the immune system. Relationship between the content of lymphocyte subpopulations (CD3+, CD4+, CD8+, CD20+) in the blood and immunoglobulins (IgG, IgM, IgA) with parameters of semi-quantitative evaluation of the activity of hepatitis and the stage of liver fibrosis in children with chronic virus hepatitis B, C, B + C was studied. The characteristic feature of all hepatitis was a decrease in the number of T lymphocytes CD4+ below the normal level and an increase in the content of B lymphocytes. The correlation between the morphological activity of hepatitis and the amount of T lymphocytes CD8+ was established only in chronic hepatitis B. In chronic hepatitis B and B + C the absolute amount of blood lymphocytes decreased with the increase of the age of the patients, but in chronic hepatitis B this was accompanied by the decrease of the morphological activity of hepatitis and in hepatitis B + C by its increase. The amount of lymphocytes CD4+ rose with the increase of liver fibrosis in chronic hepatitis B. In children with chronic hepatitis C and B + C the amount of blood lymphocytes was found to be unrelated to the morphological activity of hepatitis.     

IL28B基因多态性检测的质粒标准品构建

人类白介素28b（IL28b）的SNP位点rs12980275的多态性（AA、AG和GG）与聚乙二醇干扰素、利巴韦林联合治疗的效果具有显著相关性。为了确保rs12980275预测丙型肝炎患者抗病毒治疗效果的价值,需要构建标准品作为rs12980275检测的标准对照。提取人类外周血基因组DNA,以IL28B SNP rs12980275为目的基因片段设计引物,进行PCR扩增;纯化目的片段与pGM-T Vector连接并转化到大肠杆菌中;提取重组质粒DNA,并进行PCR、测序鉴定。结果 IL28B SNP rs12980275目的片段制备成功,获得稳定的重组质粒,保证了目的片段的特异性与序列完整性。成功构建了IL28B基因SNP rs12980275突变检测的AA、AG和GG 3种质粒标准品,可作为预测丙型肝炎患者抗病毒治疗效果rs12980275突变检测的阳性质控物。     

Alpha interferon inhibits hepatitis C virus replication in primary human hepatocytes infected in vitro

Chronic hepatitis C is a common cause of liver disease, the complications of which include cirrhosis and hepatocellular carcinoma. Treatment of chronic hepatitis C is based on the use of alpha interferon (IFN-alpha). Recently, indirect evidence based on mathematical modeling of hepatitis C virus (HCV) dynamics during human IFN-alpha therapy suggested that the major initial effect of IFN-alpha is to block HCV virion production or release. Here, we used primary cultures of healthy, uninfected human hepatocytes to show that: (i) healthy human hepatocytes can be infected in vitro and support HCV genome replication, (ii) hepatocyte treatment with IFN-alpha results in expression of IFN-alpha-induced genes, and (iii) IFN-alpha inhibits HCV replication in infected human hepatocytes. These results show that IFN-alpha acts primarily through its nonspecific antiviral effects and suggest that primary cultures of human hepatocytes may provide a good model to study intrinsic HCV resistance to IFN-alpha.