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。     

Apoptosis and apoptosis related proteins in chronic viral liver disease

Background: Apoptosis may be an important mechanism of hepatocyte death in chronic viral liver disease. Methods: We studied apoptosis in liver biopsies from 30 patients with chronic viral hepatitis and 8 patients with viral cirrhosis by the TUNEL method. 12 cases of non-alcoholic steatohepatitis and 12 cases of primary biliary cirrhosis were used as non-viral disease controls. Immunohistochemical expression of p53, p21/waf1, bcl-2 and mdm-2 proteins was also studied in the same patients. Results: A statistically significant increase of apoptotic liver cells was found in severe chronic viral hepatitis (5.3 ± 0.3%), cirrhosis (3.4 ± 0.5%) and PBC (4.4 ± 0.4%) cases compared to patients with non-alcoholic steatohepatitis (0.8 ± 0.3%). The expression of p53 protein was increased in the cases of viral cirrhosis and in chronic severe viral hepatitis whereas in the cases of chronic mild hepatitis, PBC and non-alcoholic steatohepatitis we found no expression of p53. P21/waf1 expression was increased in severe chronic hepatitis, cirrhosis and PBC cases compared to mild hepatitis and non-alcoholic steatohepatitis cases. However no induction of mdm-2 was observed in the subgroups of chronic liver disease. Bcl-2 was expressed only in epithelium of bile ducts and mononuclear cells of the portal tracts and liver lobules. A weaker Bcl-2 expression was noted in the epithelium of bile ducts of 7/12 PBC cases. Conclusion: Our results provide evidence of increased apoptosis in severe chronic viral liver disease, suggesting that apoptotic cell death might be involved in the pathogenesis of hepatocellular damage of viral hepatitis and cirrhosis. Furthermore we analysed part of the apoptotic pathways implicated in the above process and found an increased expression of p21/waf1, probably p53 mediated, without overexpression of the apoptosis inhibiting bcl-2 and mdm-2 proteins. By contrast p21/waf1 overexpression in PBC seems to be propagated by a p53 independent mechanism.     

Familial Clustering of Hepatitis B Antigen: A Study in Relatives of Patients with Liver Diseases and Hepatitis B Antigenaemia

Twelve of the 100 family contacts of 29 patients with transient and persistent hepatitis B antigenaemia were found to be positive for hepatitis B antigen (HBAg). No relation was found between familial clustering and the nature of liver disease or the duration of antigenaemia in the index cases.Eight affected relatives were apparently healthy carriers of HBAG, one had cirrhosis, and three (in the same family) developed acute viral hepatitis.The absence of parenteral exposure in the HBA,-positive family contacts and the identity in antigenic determinants d or y with those of the index cases, suggest a non-parenteral spread of HBAg in families of patients with HBAg-associated liver diseases.     

Evaluation of serum guanase in hepatic diseases

Serum guanase activity was measured in 20 healthy adults and in 62 patients with acute viral hepatitis, chronic active hepatitis, chronic persistent hepatitis, liver cirrhosis and fatty liver. Guanase and gamma-GT in patients were elevated in 87 and 64%, respectively. Elevated guanase activities were found in most cases of acute viral hepatitis, as well as in chronic hepatopathies. In patients with acute viral hepatitis pathologic activities of guanase were found following partial or total normalization of other liver function tests.     

Epidemic focus of non-A, non-B viral hepatitis in a plasmapheresis unit]

Non-A, non-B hepatitis has been diagnosed in 12 blood donors in a plasmapheresis unit. The course of the disease has been symptomatic, accompanied by jaundice, fatigue, and nausea in 8 cases, and subclinical in the remaining 4 patients. Nine patients were followed-up to 2 years and only 2 patients liver biochemical tests were normalized permanently. The biopsies performed, a year after the acute phase of hepatitis period revealed chronic active disease in patients, chronic persistent hepatitis in 2 patients, acute hepatitis in one, and normal liver in one patient. Repeated liver biopsies, performed one year later, have basically shown similar lesions except one patient in whom chronic active hepatitis progressed to incipient liver cirrhosis. No symptoms of the disease have been usually noted in patients with chronic form of the disease, and liver function tests have occasionally been normal.     

Viral hepatitis and hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors in the world. The incidence of HCC varies considerably with the geographic area because of differences in the major causative factors. Chronic hepatitis B and C, mostly in the cirrhotic stage, are responsible for the great majority of cases of HCC worldwide. The geographic areas at the highest risk are South-East Asia and sub-Saharan Africa, here hepatitis B is highly endemic and is the main cause of HCC. In areas with an intermediate rate of HCC such as Southern Europe and Japan, hepatitis C is the predominant cause, whereas in low rate areas such as Northern Europe and the USA, HCC is often related to other factors as alcoholic liver disease. There is a rising incidence in HCC in developed countries during the last two decades, due to the increasing rate of hepatitis C infection and improvement of the clinical management of cirrhosis.

Methods

This article reviews the literature on hepatitis and hepatocellular carcinoma. The Medline search was carried out using these key words and articles were selected on epidemiology, risk factors, screening, and prevention of hepatocellular carcinoma.

Results

Screening of patients with advanced chronic hepatitis B and C with hepatic ultrasound and determination of serum alfa-fetoprotein may improve the detection of HCC, but further studies are needed whether screening improves clinical outcome. Hepatitis B and C viruses (HBV/HCV) can be implicated in the development of HCC in an indirect way, through induction of chronic inflammation, or directly by means of viral proteins or, in the case of HBV, by creation of mutations by integration into the genome of the hepatocyte.

Conclusion

The most effective tool to prevent HCC is avoidance of the risk factors such as viral infection. For HBV, a very effective vaccine is available. Preliminary data from Taiwan indicate a protective effect of universal vaccination on the development of HCC. Vaccination against HBV should therefore be a health priority. In patients with chronic hepatitis B or C, interferon-alfa treatment in a noncirrhotic stage is protective for HCC development in responders, probably by prevention of cirrhosis development. When cirrhosis is already present, the protective effect is less clear. For cirrhosis due to hepatitis B, a protective effect was demonstrated in Oriental, but not in European patients. For cirrhosis due to hepatitis C, interferon-alfa treatment showed to be protective in some studies, especially in Japan with a high incidence of HCC in untreated patients. Virological, but also merely biochemical response, seems to be associated with a lower risk of development of HCC. As most studies are not randomized controlled trials, no definitive conclusions on the long-term effects of interferon-alfa in HBV or HCV cirrhosis can be established. Especially in hepatitis C, prospective studies should be performed using the more potent reference treatments for cirrhotics, namely the combination of peginterferon and ribavirin.     

Serum trypsin inhibitory activity and alpha-1-antitrypsin level in liver diseases

Alpha-1-antitrypsin level and serum trypsin inhibitory activity were measured in patients with viral hepatitis, chronic hepatitis and liver cirrhosis. The most pronounced discrepancy between these two parameters were observed in patients with liver cirrhosis: the increase of alpha-1-At level was not accompanied by adequate increase of trypsin inhibitory activity. Some mechanisms potentially responsible for this discrepancy are discussed.     

Hepatitis B viral factors and clinical outcomes of chronic hepatitis B

Hepatitis B virus (HBV) infection is an important health problem and the major cause of chronic hepatitis, cirrhosis as well as hepatocellular carcinoma (HCC) worldwide. The natural history of chronic HBV infection can be divided into 4 dynamic phases in HBV carriers who acquire the virus early in life. In general, the frequency and severity of hepatitis flares in the immune clearance or reactivation phase predict disease progression in HBV carriers, and early HBeAg seroconversion typically confers a favorable outcome. In contrast, late or absent HBeAg seroconversion after multiple hepatitis flares accelerates the progression of chronic hepatitis to cirrhosis. Recently, several hepatitis B viral factors predictive of clinical outcomes have been identified. For example, serum HBV DNA level at enrollment is the best predictor of adverse outcomes (cirrhosis, HCC and death from liver disease) in adults with chronic HBV infection. In addition, HBV genotype C, basal core promoter (BCP) mutant and pre-S deletion mutant are associated with increased risk of HCC development. In conclusion, hepatitis B viral factors such as serum HBV DNA level, genotype and mutants have already been clarified to influence disease progression of chronic hepatitis B. Further studies are needed to investigate the pathogenic mechanism of each viral factor.     

Alcohol as a pathological factor for patients with acute and chronic viral hepatitis and liver cirrhosis

The investigations have shown presence of HBsAg in the blood sera of 4% of alcohol abusers and in 17.7% of chronic alcoholics. Among 274 patients with acute viral hepatitis A, more than 50% abuse alcohol. The study has revealed that the lipid spectrum has its specific features in hepatitis patients abusing alcohol and chronically addicted to it. Among patients with chronic persistent hepatitis and cirrhosis of the liver, the combined effects of hepatitis B virus and alcohol have been revealed in 50%.     

CD137-mediated pathogenesis from chronic hepatitis to hepatocellular carcinoma in hepatitis B virus-transgenic mice

Chronic hepatitis B virus (HBV) infection is characterized by sustained liver inflammation with an influx of lymphocytes, which contributes to the development of cirrhosis and hepatocellular carcinoma. The mechanisms underlying this immune-mediated hepatic pathogenesis remain ill defined. We report in this article that repetitive infusion of anti-CD137 agonist mAb in HBV-transgenic mice closely mimics this process by sequentially inducing hepatitis, fibrosis, cirrhosis, and, ultimately, liver cancer. CD137 mAb initially triggers hepatic inflammatory infiltration due to activation of nonspecific CD8(+) T cells with memory phenotype. CD8(+) T cell-derived IFN-γ plays a central role in the progression of chronic liver diseases by actively recruiting hepatic macrophages to produce fibrosis-promoting cytokines and chemokines, including TNF-α, IL-6, and MCP-1. Importantly, the natural ligand of CD137 was upregulated significantly in circulating CD14(+) monocytes in patients with chronic hepatitis B infection and closely correlated with development of liver cirrhosis. Thus, sustained CD137 stimulation may be a contributing factor for liver immunopathology in chronic HBV infection. Our studies reveal a common molecular pathway that is used to defend against viral infection but also causes chronic hepatic diseases.     

病毒性肝病抗病毒治疗期间新发肝癌7例临床分析

目的:探讨病毒性肝炎肝硬化患者经抗病毒治疗仍发生原发性肝癌的原因。方法:回顾性分析兰州大学第一医院东岗院区肝病中心在2012年10月-2013年6月收治的7例病毒性肝炎肝硬化患者在规范抗病毒治疗期间新发原发性肝癌的临床资料、抗病毒治疗情况。结果:7例患者中有HBV感染6例,HCV感染1例;慢性肝炎2例,肝硬化5例;HBeAg阴性5例;3例合并糖尿病;经抗病毒治疗后病毒载量均处于低度复制或不可测状态。结论:病毒性肝炎肝硬化患者经抗病毒治疗不能完全消除原发性肝癌发生的风险,病毒载量、HBeAg阴性、糖尿病、肝硬化等可能是肝癌发生的危险因素。     

Production of profibrotic cytokines by invariant NKT cells characterizes cirrhosis progression in chronic viral hepatitis

Invariant (inv)NKT cells are a subset of autoreactive lymphocytes that recognize endogenous lipid ligands presented by CD1d, and are suspected to regulate the host response to cell stress and tissue damage via the prompt production of cytokines. We investigated invNKT cell response during the progression of chronic viral hepatitis caused by hepatitis B or C virus infection, a major human disease characterized by a diffused hepatic necroinflammation with scarring fibrotic reaction, which can progress toward cirrhosis and cancer. Ex vivo frequency and cytokine production were determined in circulating and intrahepatic invNKT cells from controls (healthy subjects or patients with nonviral benign or malignant focal liver damage and minimal inflammatory response) or chronic viral hepatitis patients without cirrhosis, with cirrhosis, or with cirrhosis and hepatocellular carcinoma. invNKT cells increase in chronically infected livers and undergo a substantial modification in their effector functions, consisting in the production of the type 2 profibrotic IL-4 and IL-13 cytokines, which characterizes the progression of hepatic fibrosis to cirrhosis. CD1d, nearly undetectable in noncirrhotic and control livers, is strongly expressed by APCs in cirrhotic ones. Furthermore, in vitro CD1d-dependent activation of invNKT cells from healthy donors elicits IL-4 and IL-13. Together, these findings show that invNKT cells respond to the progressive liver damage caused by chronic hepatitis virus infection, and suggest that these cells, possibly triggered by the recognition of CD1d associated with viral- or stress-induced lipid ligands, contribute to the pathogenesis of cirrhosis by expressing a set of cytokines involved in the progression of fibrosis.     

Dynamics of immunological indices in patients with chronic viral hepatitis B and the effect of thymalin therapy

The work deals with the results of the study of T-lymphocytes and their subpopulations (active, thermostable, theophylline-sensitive and theophylline-resistant) in 102 children with chronic viral hepatitis B, depending on the effectiveness of thymalin therapy. The sensitization of lymphocytes to specific antigens was studied. Among patients with chronic viral hepatitis B and cirrhosis of the liver the homozygous phenotype of haptoglobin is registered essentially more frequently (63.6% and 82.4% respectively) than among healthy persons (44.0%). The patients of this group showed a decrease in the number of T-lymphocytes, disturbances in the suppressor/helper ratio: hypersuppression in persisting hepatitis and hyposuppression in active hepatitis. In 71.6% of cases thymalin therapy produced an effect manifested by clinico-biochemical remission, an increase in the number of T-lymphocytes, thermostable cells and the normalization of the T-suppressor/T-helper ratio. In these patients sensitization to HBsAg essentially decreased (from 30.5% to 13.9%), while sensitization to human liver lipoprotein retained its high level even after treatment with thymalin.     

Prognosis for the patients with alcoholic and nonalcoholic liver disease

The purpose of this investigation was to determine the role of alcohol in development of progressive liver disease. For this purpose, 41 alcoholic patients were followed up for 5 years. Criteria for alcohol abuse was that the patients were enjoying 20 g alcohol daily in a period of 5 years for females and respectively 60 g daily for males. In the same time a group of 51 nonalcoholic patients with histologically proven chronic liver disease were investigated. In all 92 patients chronic liver disease and progression of the disease was proven by liver biopsy during a 5-years follow-up. In sera of all patients the markers of hepatitis viruses B, D and C were continuously determined and chronic viral hepatitis was excluded. Also, autoimmune chronic hepatitis was excluded. The results of the investigation showed that alcoholics develop cirrhosis hepatitis, in most cases 78.04%. The most progressive chronic liver diseases--cirrhosis and hepatocellular carcinoma--are significantly present among nonalcoholics (p < or = 0.05). In the mentioned investigation a large group of 51 patients with severe chronic hepatitis without a proven etiology of disease was found and it deserves priority in future research.     

Cell-mediated Immune Responses in Chronic Liver Diseases

Studies of the cell-mediated response to liver antigens, using the leucocyte migration test, in 163 patients with various liver disorders showed that abnormal responses were almost confined to active chronic hepatitis (53% abnormal), primary biliary cirrhosis (64%), and cryptogenic cirrhosis (29%). The test was also abnormal in five out of seven patients with jaundice due to drug hypersensitivity and in one patient with acute infectious hepatitis at a time when mitochondrial antibodies were present in the serum. More of those with active chronic hepatitis on prednisone or azathioprine had normal tests than of those who were untreated, and in 8 out of 10 examined serially during therapy there was an accompanying improvement in leucocyte migration. Abnormal responses to salivary gland or kidney antigens were also found in nearly half of those with features of Sjögren''s syndrome or renal tubular acidosis as part of a multisystem involvement—this, though occurring in cryptogenic cirrhosis, was found with greater frequency in active chronic hepatitis and primary biliary cirrhosis. These cell-mediated immune responses, perhaps triggered by the initial damage to the liver from viral or other agents, may be responsible both for the perpetuation of the liver disease and, because of common surface antigens, for the damage to other organs.     

Elevation of liver-galactosylhydroxylysyl glucosyltransferase activity in human primary hepatocellular carcinoma

The activity of L-GGT (EC 2.4.1.66), an enzyme catalyzing the intracellular biosynthesis of collagen, was determined in human primary hepatic cancer, acute viral hepatitis and cirrhotic liver tissues and compared to the mean level of enzyme activity in normal human liver tissues. The mean levels of L-GGT activity in primary hepatocellular carcinoma (PHC), acute viral hepatitis and cirrhotic tissues were 7.78, 2.69 and 2.16 times the mean level of enzyme activity in normal human liver tissues. The mean level of L-GGT activity in PHC was 3.61 times the mean level of L-GGT activity in cirrhosis and 2.90 times the mean value of liver enzyme activity in acute viral hepatitis. The findings in this study provide a basis for the highly elevated serum values of this intracellular enzyme in patients with primary hepatic cancer and the data indicate that L-GGT activity may be increased in primary liver cancer to compensate for an increased rate of collagen synthesis.     

Undifferentiated patterns of key carbohydrate-metabolizing enzymes in injured livers. II. Human viral hepatitis and cirrhosis of the liver.

Activities of key carbohydrate-metabolizing enzymes were determined on biopsied liver tissues obtained from patients with acute and chronic viral hepatitis and postnecrotic cirrhosis of the liver. The results indicated that the activities of fetal or prototype enzymes, low-Km hexokinases, glucose-6-phosphate dehydrogenase and pyruvate kinase type M2 increased, while those of adult type liver enzymes, glucokinase, glucose-6-phosphatase, fructose-1, 6-diphosphatase and pyruvate kinase type L decreased in livers of these cases. Phosphofructokinase activity tended to increase only acute hepatitis. Principal component analysis revealed that the enzyme patterns of acute hepatitis and liver cirrhosis were most deviated from the control and closely resembled those of hepatocellular carcinomas.     

Plasmapheresis and amino acid mixtures of "Aminosteril-Hepa" type preparations in treating hepatic encephalopathy]

An effect of Aminosteril-Hepa intravenous infusions or plasmapheresis on selected amino acids, ammonia, alpha-aminonitrogen serum levels and serum GGTP activity was analysed in 28 patients with liver cirrhosis with and without hepatic encephalopathy. The patients were given protein controlled dietary treatment. It was found, that plasmapheresis exerted more potent effect on previously elevated ammonia and serum alpha-aminonitrogen levels as well as serum GGTP activity than intravenous infusions of Aminosteril-Hepa. It was clearly seen in patients with liver cirrhosis without hepatic encephalopathy. Aminosteril-Hepa intravenous infusions decreased serum glutamine levels to higher degree than plasmapheresis. Both types of therapy have had no significant effect on serum phenylalanine, tyrosine, and tryptophan levels in all patients.     

Immunopathogenesis of hepatitis C virus infection

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

Immunology of hepatitis B virus and hepatitis C virus infection

More than 500 million people worldwide are persistently infected with the hepatitis B virus (HBV) and/or hepatitis C virus (HCV) and are at risk of developing chronic liver disease, cirrhosis and hepatocellular carcinoma. Despite many common features in the pathogenesis of HBV- and HCV-related liver disease, these viruses markedly differ in their virological properties and in their immune escape and survival strategies. This review assesses recent advances in our understanding of viral hepatitis, contrasts mechanisms of virus-host interaction in acute hepatitis B and hepatitis C, and outlines areas for future studies.