Immunopathogenesis of viral hepatitis C. Immunological markers of the disease progression

Results of studies of immune response during hepatitis C virus (HCV) infection were reviewed in order to reveal immunologic markers of the disease progression. Genetic heterogeneity of HCV and immunogenetic features of the host determine heterogeneity of immune response to the virus and differences in the course of the disease and outcomes. Spontaneous elimination of HCV-infection in acute phase occurs due to vigorous and sustained multispecific Th1-response toviral antigens. During such response proliferation of virus-specific CD4+ T-cells and secretion of IFN-gamma by them are observed, otherwise chronic hepatitis develops. Great importance in persistence of HCV as well as in quantitative and functional suppression of HCV-specific CD8+ T-cells has increased number of CD4+ CD25+ regulatory T-cells. Cellular immune response plays a key role not only in the elimination of HCV, but also in liver pathology associated with HCV-infection. Progression of the process and shift to its chronic form are also associated with decrease of production of IFN-gamma, alpha, IL-2 by peripheral blood mononuclear cells and increase of TNF-alpha, IFN-gamma, IL-4, IL-2r levels in blood serum.     

Characteristics of immune response regulation in viral hepatitis A and B

In 272 patients with virus hepatitis A and B the content of theophylline-sensitive lymphocytes (T-suppressors) and theophylline-resistant lymphocytes (T-helpers) in the peripheral blood was determined. Differences in the content of T-suppressors in cases of acute virus hepatitis A and B with an equal degree of severity were revealed: at the peak of hepatitis A infection in the mild form of the disease the number of the cells was decreased, while at the peak of hepatitis B infection an increase in their number was observed in the mild and moderate forms of the disease and a decrease, in the severe form of the disease. In chronic persistent hepatitis a decrease in the content of T-suppressors and an increase in the content of T-helpers were observed, and in chronic active hepatitis (at the period of remission) and increase in the T-helpers occurred. Changes in the content of the cells of both types are not characteristic of HBsAg carriership.     

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.     

Deranged metabolism of cyclic nucleotides in liver diseases

To clarify the factor(s) responsible for changes in the plasma cyclic GMP concentration in liver diseases, we measured the plasma levels of cyclic GMP, along with cyclic AMP, in various clinical stages of chronic liver diseases and acute hepatitis. The level of cyclic GMP was found to increase significantly in the early stage of acute hepatitis, in the decompensated stage of liver cirrhosis, and in malignant diseases. In the former two states, it is postulated that decreased hepatic mass is responsible for the changes in the plasma cyclic GMP concentration. The retention rate of indocyanin green (ICGR15) was highly correlated with the plasma cyclic GMP level. The result suggests that the determination of plasma cyclic GMP is useful as an index of the reserve function of the liver in disease states.     

Diseases with chronic stage in a population with varying size

An epidemiological model of hepatitis C with a chronic infectious stage and variable population size is introduced. A non-structured baseline ODE model which supports exponential solutions is discussed. The normalized version where the unknown functions are the proportions of the susceptible, infected, and chronic individuals in the total population is analyzed. It is shown that sustained oscillations are not possible and the endemic proportions either approach the disease-free or an endemic equilibrium. The expanded model incorporates the chronic age of the individuals. Partial analysis of this age-structured model is carried out. The global asymptotic stability of the infection-free state is established as well as local asymptotic stability of the endemic non-uniform steady state distribution under some additional conditions. A numerical method for the chronic-age-structured model is introduced. It is shown that this numerical scheme is consistent and convergent of first order. Simulations based on the numerical method suggest that in the structured case the endemic equilibrium may be unstable and sustained oscillations are possible. Closer look at the reproduction number reveals that treatment strategies directed towards speeding up the transition from acute to chronic stage in effect contribute to the eradication of the disease.     

The comparative characteristics of the indices of lymphocyte and neutrophil functional activity in patients with HIV infection and chronic viral hepatitis B]

In 34 patients with human immunodeficiency virus (HIV) infection at the asymptomatic stage and 29 patients with chronic viral hepatitis B at the period of exacerbation (of these 14 patients had chronic persistent hepatitis and 15 patients had chronic active hepatitis) the complex study of the functional activity of lymphocytes and neutrophils was carried out by cytochemical methods with the simultaneous determination of the content of immunoregulating lymphocyte subpopulations. In patients with chronic active hepatitis a decrease in the percentage and the absolute number of helper T-lymphocytes and the ratio of CD4/8 in comparison with those in patients with HIV infection were revealed. At the same time patients with HIV infection exhibited more pronounced decrease in the activity of all lymphocytic enzymes under study (neutrophil esterase, acidic phosphatase and succinate dehydrogenase in lymphocytes), as well as in the activity of myeloperoxidase and the content of cation proteins and glycogen in neutrophils in comparison with patients having chronic active hepatitis.     

恩替卡韦联合血浆置换治疗慢性乙型重型肝炎的研究

目的初步探讨恩替卡韦联合血浆置换治疗慢性乙型重型肝炎患者的疗效。方法选取40例慢性乙型重型肝炎患者,在常规内科治疗及恩替卡韦0.5 mg/d抗病毒治疗基础上联合血浆置换治疗。同时选取38例慢重肝患者为对照组,给予常规内科治疗及恩替卡韦0.5 mg/d抗病毒治疗。比较2组患者在慢性乙型重型肝炎早、中和晚期存活率的差异。结果联合血浆置换组生存率为72.5%,而对照组生存率为50%(χ2=4.168,P=0.041)。其中,中期慢重肝患者联合血浆置换治疗,其生存率为72.2%,而对照组生存率为38.9%(χ2=4.050,P=0.044),早期和晚期慢重肝患者联合血浆置换治疗,其生存率与对照组比差异无统计学意义(P0.05)。结论慢性乙型重型肝炎中期患者采用恩替卡韦联合血浆置换治疗能提高患者生存率。     

Detection of a new antibody system reacting with Dane particles in hepatitis B virus infection.

Antibodies in the serum reacting with antigens on the surface of radiolabelled Dane particles distinct from hepatitis B surface and core antigens (HBsAg and HBcAg) were detected, using a double antibody precipitation assay, in 12 out of 15 patients early in the course of acute type B hepatitis and at the time of disappearance of circulating Dane particles. No such antibody activity was found in 15 of the 16 patients with HBsAg-positive chronic active hepatitis, 13 of whom had complete Dane particles in the serum. In a group of 16 asymptomatic HBsAg carriers (without Dane particles in serum) antibody activity was shown in nine. This demonstration of antibodies precipitating Dane particles may be relevant to the clearance of circulating hepatitis B virions and the termination of infection in acute type B hepatitis. Their absence in all but one of the cases of chronic active hepatitis might explain why the virus infection persists in this group of patients.     

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.     

Cellular immune response to hepatitis B virus-encoded antigens in acute and chronic hepatitis B virus infection

The proliferative response of PBMC to hepatitis B virus (HBV) envelope, core, and e Ag was analyzed prospectively in 21 patients with acute self-limited HBV infection and compared with the response of patients with chronic HBV infection and different levels of HBV replication (i.e., hepatitis e Ag (HBeAg)- or anti-HBe-positive) and liver damage (i.e., chronic active hepatitis or chronic asymptomatic carriers). Our results indicate that: 1) HBV-infected subjects who develop a self-limited acute hepatitis show a vigorous PBMC response to hepatitis B core Ag and HBeAg, as expression of T cell activation; 2) appearance of a detectable lymphocyte response to HBV nucleocapsid Ag is temporally associated with the clearance of HBV envelope Ag; 3) in patients with chronic HBV infection the level of T cell responsiveness to hepatitis B core Ag and to HBeAg is significantly lower than that observed during acute infection; 4) T cell sensitization to HBV envelope Ag in acute and chronic HBV infection is usually undetectable and when measurable is expressed transiently and at low levels. These results may reflect immune events of pathogenetic relevance with respect to evolution of disease and viral clearance.     

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.     

Virus-specific CD8+ lymphocytes share the same effector-memory phenotype but exhibit functional differences in acute hepatitis B and C

Hepatitis B and hepatitis C viruses (HBV and HCV) are both noncytopathic and can cause acute and chronic infections of the liver. Although they share tropism for the same organ, development of chronic hepatitis is much more frequent following HCV infection, suggesting different mechanisms of viral persistence. In this study, we show that circulating HBV- and HCV-specific tetramer-positive CD8 cells during the acute phase of hepatitis B and C belong almost entirely to an effector-memory subset (CCR7(-) CD45RA(-)). Despite this phenotypic similarity, HBV- and HCV-specific CD8 cells show striking functional differences. HBV-specific tetramer-positive CD8 cells express high perforin content ex vivo, expand vigorously, and display efficient cytotoxic activity and gamma interferon (IFN-gamma) production upon peptide stimulation. A comparable degree of functional efficiency is maintained after the resolution of hepatitis B. In contrast, HCV-specific CD8 cells in the acute phase of hepatitis C express significantly lower levels of perforin molecules ex vivo and show depressed CD8 function in terms of proliferation, lytic activity, and IFN-gamma production, irrespective of the final outcome of the disease. This defect is transient, because HCV-specific CD8 cells can progressively improve their function in patients with self-limited hepatitis C, while the CD8 function remains persistently depressed in subjects with a chronic evolution.     

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。     

Thematic review series: the immune system and atherogenesis. The unusual suspects:an overview of the minor leukocyte populations in atherosclerosis

Atherosclerosis is a complex inflammatory disease process involving an array of cell types and interactions. Although macrophage foam cells and vascular smooth muscle cells constitute the bulk of the atherosclerotic lesion, other cell types have been implicated in this disease process as well. These cellular components of both innate and adaptive immunity are involved in modulating the response of macrophage foam cells and vascular smooth muscle cells to the retained and modified lipids in the vessel wall as well as in driving the chronic vascular inflammation that characterizes this disease. In this review, the involvement of a number of less prominent leukocyte populations in the pathogenesis of atherosclerosis is discussed. More specifically, the roles of natural killer cells, mast cells, neutrophils, dendritic cells, gammadelta T-cells, natural killer T-cells, regulatory T-cells, and B-cells are addressed.     

Tendency and analysis of the epidemic situation in parenteral virus hepatitis B and C in the Russian Federation and a number of its regions

As revealed in the present survey, during the last 3 years, against a background of decreased number of registered cases of acute hepatitis B (HB) and acute hepatitis C (HC), an increase in the proportion of patients with the chronic forms of these diseases was observed. The incidence rate of carriership of hepatitis B (HBV) and hepatitis C viruses (HCV) is many times greater than morbidity rates in acute and chronic forms of the disease. Such differences could be due to imperfect laboratory and clinical diagnosis. The registered statistics on HBV and HCV carriership included newly detected HBsAg and anti-HCV in the absence of clinical manifestations, which did not reflect the true spread of HBV and HCV in a given territory. The group of HBV and HCV carriers was found to include a considerable proportion of patients with asymptomatic form of HB and HC. It was testing for HBsAg, anti-HCV only without determination of virus replication markers (anti-HBc IgM, HBV DNA, anti-HCV IgM, HCV RNA) that seemingly determined the category of carriers greatly exceeding the true incidence. To obtain reliable epidemiological information, the complex detection of HB and HC infection markers is necessary.     

Analysis of T cell receptor Vβ gene usage during the course of disease in patients with chronic hepatitis B

The T cell receptor (TCR) is a heterodimeric molecule expressed on the surface of T cells and recognizes foreign peptides presented by the major histocompatibility complex on the surface of antigen-presenting cells or virusinfected cells. Analysis of TCR usage by T cells which recognize hepatitis B virus (HBV) provides further insight into the participation of T cell populations during the course of disease. In this study, we examined the T-cell-proliferative response and the TCR V gene usage of peripheral blood mononuclear cells in 3 patients with clinical evidence typical of chronic hepatitis B. All 3 patients had significant T-cell proliferative responses against HBV core antigen (HBcAg) during the remission stage, while no responses were detected during the acute exacerbation stage. In addition, the TCR V₇ gene was utilized more frequently in T cells recognizing HBcAg during remission, while TCR V₁ and V₂ were utilized at a higher percentage during acute exacerbation. On the contrary, the T cell proliferative response against HBV surface antigen was undetectable and no specific V gene was utilized more frequently by all 3 patients, regardless of disease state. Our longitudinal studies, although based on a small sample of patients, demonstrate that the population of HBcAg-activated T cells alters during the course of disease in chronic hepatitis B patients.     

Level of Tx1- and Tx2-type cytokines in blood sera of hepatitis C patients

The content of cytokines of type Tx1 (IL-2 and IFN-gamma) and type Tx2 (IL-4) in blood sera of 132 patients with hepatitis C and the combined form of hepatitis B + C was studied. For control, blood sera taken from healthy donors were used. A significant increase, in comparison with the control, in the content of IL-4 in all subgroups of the patients was registered. The content of IFN-gamma reached the maximum level in patients with acute hepatitis C with the positive result of the polymerase chain reaction (PCR) for the virus (216.4 and 46.4 pg/ml respectively) and was somewhat lower in acute hepatitis C with the negative PCR-result (77.7 and 9.6 pg/ml), mean while in the chronic course of hepatitis C these data were within the limits of control values irrespective of the results of PCR. In case of mixed infection in the acute clinical form a significant increase in the concentration of IFN-gamma (34.4 pg/ml) in comparison with the control (25.3 pg/ml) was observed. The content of IFN-gamma in patients with acute hepatitis C and the positive result of the test for NS antibodies also reached the maximum level (207.3 and 42.7 pg/mg respectively). But in contrast to hepatitis C in the acute form with the negative results of PCR in patients with hepatitis C in the acute form and the negative results of the NS test these data were within the limits of control values, as well as in the chronic course of hepatitis C irrespective of the results of the NS antibodies serum test. In case of mixed infection a significant increase in the concentration of IFN-gamma was registered in the subgroup of patients with the acute form of NS+ (39.9 pg/ml). The data obtained in this study were indicative of significant changes in the serum profile of serum cytokines of types Tx1 and Tx2 in different forms and courses of virus hepatitis. This makes it possible to believe that the chronization of the process was associated with the prevalence of the Tx2 function.     

Seroepidemiology of hepatitis C virus in Beijing, China

To investigate the seroprevalence of hepatitis C virus (HCV) in China we tested sera from healthy individuals without hepatitis and no history of parenteral blood exposure and from patients admitted to a hepatitis hospital in Beijing. Sera were tested for anti-HCV by first-generation enzyme immunoassay; selected positives were tested with two second-generation EIAs, one utilizing recombinant antigens and the other synthetic peptides. We found anti-HCV with the following frequencies: 10 of 164 (6%) individuals with no disease; 2 of 36 (5.5%) patients with acute non-A non-B hepatitis (NANBH); 26 of 39 (67%) patients with post-transfusion NANBH; 10 of 34 (29%) patients with chronic hepatitis negative for hepatitis B surface antigen (HBsAg); 3 of 30 (10%) patients with chronic HBsAg-positive hepatitis; 0 of 19 patients with acute HBsAg-positive hepatitis. Of 24 repeat-positive sera, 19 were positive by both and 4 by one second-generation tests. We conclude that hepatitis C infection is common in China, that it contributes substantially to the incidence of post-transfusion hepatitis, and that HCV plays a significant role in both acute and chronic hepatitis. Further studies are needed to extend these observations and to define the predominant routes of transmission of HCV in China.     

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.     

Several indices of the peripheral immune system in clean up team workers and patients who survived acute radiation disease 5 years after effects of the radiation accident factors]

A group of liquidators and patients survived acute radiation sickness (ARS) was studied five years after the effect of radiation factors resulted from the Chernobyl A.P.S. disaster. Studied were the number of T-lymphocytes (SD2+, SD3+, SD5+), subpopulations SD16+ and SD25+, the content of SD16+ and SD25+ lymphocytes and B-cells, as well as the levels of serum IgM, A, G; determined was the concentration of serum alpha 1-thymosin. A decrease was noted in the number of T-cells of the examined patients, with respect to all markers studied: the number of SD4+ cells was found decreased in patients with ARS sequelae and normal in liquidators. The decrease in serum alpha 1-thymosin was a function of dose. Dynamics of changes in the T-cells of the examinees may reflect the new trends in the radiation response of T-lymphocytes which were not directly related to initial damages to the latter. The injury to the stroma of the thymus and especially to its epithelial cells may be the basis for later postirradiation damages to the immune system. The decrease in the concentration of alpha 1-thymosin in the blood serum of the examinee is the manifestation of the thymus hypofunction. In liquidators and patients with the ARS sequelae the number of SD25+ cells increased markedly indicating the existence of the source of endogenous cell activation. The content of B-lymphocytes in all studied groups of patients was reduced which may serve as a criterion of chronic stress.