Role of hepatitis C virus infection in spontaneous hepatitis B surface antigen clearance during chronic hepatitis B virus infection.

To examine the role of hepatitis C virus (HCV) infection in spontaneous hepatitis B surface antigen (HBsAg) clearance during the course of chronic hepatitis B virus (HBV) infection, serum specimens from 32 asymptomatic HBsAg carriers and 22 patients with chronic hepatitis type B who underwent spontaneous HBsAg clearance were studied for antibody to HCV (anti-HCV) using commercial EIAs. The results were compared with those of control groups matched for age, sex, hepatitis B e antigen, antibody to hepatitis delta virus, and cirrhosis. Eight (25%) of the asymptomatic carriers and 9 (41%) of the patients with chronic hepatitis were seropositive for anti-HCV in contrast to 1.6% and 9.1% of their respective control groups (P less than .01). Serum alanine aminotransferase level was persistently abnormal after HBsAg clearance in one asymptomatic carrier and in four patients with chronic hepatitis. These patients were seropositive for anti-HCV and at least one of them was negative for HBV-DNA by polymerase chain reaction. The data suggest that HCV superinfection may not only suppress HBV or terminate the HBsAg carrier state but may also assume the role of HBV as the cause of persistent hepatitis or transaminase elevation.     

Anti-pre-S antibodies in different groups of patients with hepatitis B virus infection

The anti-pre-S antibody in the samples of sera from normal healthy persons and patients with different clinical types of liver diseases due to hepatitis B virus (HBV) infection was detected by a newly established enzyme-linked immunosorbent assay technique. This test is a blocking assay where anti-pre-S antibody in the patient's serum blocks subsequent addition of horse radish peroxidase-labelled polymerized human serum albumin (pHSA) to the pHSA-receptor site of HBsAg molecules fixed on a solid surface. Anti-pre-S activity was not detected in any from 95 healthy persons who were negative for all HBV-markers or from 105 healthy HBV carriers. In 12 sera from HBV vaccine recipients, anti-pre-S activity was noted in higher proportions compared with anti-HBs, after both the second and third doses of vaccine. Anti-pre-S activity was detected in small proportions of HBsAg positive sera from acute viral hepatitis (4.2%) and chronic active hepatitis (10%). In subacute viral hepatitis patients, the anti-pre-S antibody was totally absent. However, anti-pre-S activity was recorded in high proportions of HBsAg-positive sera from patients with cirrhosis of liver (57.2%) and fulminant hepatitis (41.6%). The anti-pre-S antibodies were assumed to be implicated in the clearance of HBV particles from circulation without causing tissue damage.     

Permanent HBsAg clearance in chronic hepatitis B viral infection following acute delta superinfection

Three patients are described with chronic hepatitis B virus infection for three to six years before hepatitis delta virus superinfection occurred. Liver biopsy performed in two patients prior to their delta illness revealed chronic persistent hepatitis and chronic active hepatitis, respectively. Within one to seven months of the acute delta event, all three patients lost their circulating hepatitis B surface antigen. Subsequently, delta antibody also cleared. Clinical well-being and normal transaminases were documented over 10-44 months of follow-up. Although most cases of delta infection in chronic hepatitis B result in severe or progressive disease, a small number of patients may develop clearance of the HBsAg with clearance of both B and delta infections.     

Immune responses in hepatitis B virus infection

Hepatitis B virus infection is one of the most frequent causes of chronic liver disease worldwide. Even though a preventive vaccine is available, the search for a cure for chronically infected patients remains a high priority to reduce the morbidity and mortality from liver cirrhosis and hepatocellular carcinoma. This review summarizes the immune response in acute, self-limited and chronic hepatitis B; its differential effects on viral replication and liver injury; and prospects for immunotherapy.     

Dual chronic hepatitis B virus and hepatitis C virus infection

Dual hepatitis B virus (HBV) and hepatitis C virus (HCV) infection are common in HBV or HCV endemic areas. However, several clinical and pathogenetic issues remain unresolved. First, clinical and in vitro studies suggest the interactions between two viruses. The dynamics of the interaction in untreated setting versus treated setting and its influence on the long-term outcomes await further studies. A key issue regarding viral interactions is whether modulation of infection occurs in the same dually infected individual hepatocyte of the liver. Clarifying this issue may help to understand the reciprocal interference between HCV and HBV and provide clues for future immunopathogenetic studies. Second, the prevalence and clinical significance of coexisting occult HBV infection in patients with chronic HCV infection need further investigations. Third, combination therapy of peginterferon alfa-2a and ribavirin appears to be just as effective and safe for the treatment of hepatitis B surface antigen (HBsAg)-positive patients chronically infected with active chronic hepatitis C as it is in patients with HCV monoinfection. Nevertheless, one-third of dually infected patients with nondetectable serum HBV DNA-level pretreatment developed HBV reactivation posttreatment. How to prevent and treat this reactivation should be clarified. Furthermore, about 10% of the dually infected patients lost HBsAg. Underlying mechanisms await further investigations. Finally, the optimal treatment strategies for dually infected patients with hepatitis B e antigen-positive chronic hepatitis B should be identified in future clinical trials.     

Pregnancy and chronic hepatitis B virus infection

The combination of chronic hepatitis B virus (HBV) infection and pregnancy presents unique management questions. Aspects of care that need to be considered include effects of hepatitis B on pregnancy, effects of pregnancy itself on the course of hepatitis B infection, treatment of hepatitis B during pregnancy and prevention of mother-to-infant transmission. Chronic HBV infection is usually mild in pregnant women, but may flare shortly after delivery. Effect of HBV infection on pregnancy outcomes are generally favorable, but may depend on severity of liver disease. Mother-to-infant transmission can be minimized by current immunoprophylaxis strategies, however, high levels of viremia in mothers may be a factor in the small but reproducible failure rate of current immunoprophylaxis strategies. Use of antivirals during pregnancy needs to be individualized. Careful planning and management of pregnancy must be done among patients with chronic HBV infection.     

Detection of hepatitis B virus antigens in liver tissue. A relation to viral replication and histology in chronic hepatitis B infection

The expression of hepatitis B virus antigens was studied by double staining liver tissue with appropriate antisera and correlated with serum hepatitis B viral DNA and histology in 28 patients with disease related to chronic hepatitis B virus infection. The cellular localization of hepatitis B core and hepatitis B e antigens generally coincided, but there were important differences at a subcellular level. Thus, hepatitis B e antigen was detected in nuclei and/or cytoplasm but strong cytoplasmic hepatitis B e antigen was associated with a high serum hepatitis B viral DNA (P = 0.0017) but not with active liver disease. Hepatitis B core antigen could also be detected in nuclei and/or cytoplasm, but strong cytoplasmic hepatitis B core antigen expression, exceeding that of hepatitis B e antigen, was associated with active liver disease (P = 0.041) and not with serum hepatitis B virus DNA. The proportion of hepatocytes expressing hepatitis B surface antigen correlated inversely with the serum titer (P = 0.0017), whereas hepatitis B surface and nucleocapsid antigens were usually expressed independently. The data support the hypothesis that cytoplasmic hepatitis B core antigen and not hepatitis B e antigen is the target for immune system-mediated cytolysis of hepatocytes. Cytoplasmic hepatitis B e antigen is not associated with liver damage but is instead associated with high levels of hepatitis B virus replication.     

Hepatitis C virus infection in chronic hepatitis B virus carriers.

One hundred eighty-four patients with hepatitis B surface antigen-positive chronic hepatitis were evaluated for antibodies to hepatitis C virus (anti-HCV). Only 11 (8%) of 136 patients with hepatitis B virus (HBV) replication (HBV-DNA-positive in serum) while 7 (35%) of 20 positive for antibody to hepatitis B e antigen (anti-HBe) but HBV-DNA-negative were positive for anti-HCV. By contrast, anti-HCV was never found in 30 anti-HBe-positive "healthy" carriers. Anti-HCV was more frequent in hepatitis D virus (HDV)-positive than in HDV-negative cases (32% vs. 12%). During 1-11 years of follow-up, anti-HCV persisted in 90% of cases, who showed continuing alanine aminotransferase elevation. Liver histology deteriorated in 2 of 4 anti-HCV-positive, anti-HBe-positive, HBV-DNA-negative patients. These results demonstrate the existence of a subgroup of patients with anti-HBe-positive, HBV-DNA-negative, HDV-negative chronic hepatitis B, where HCV may play a leading role in causing liver disease.     

Principles in the management of chronic hepatitis B viral infection.

Recently licensed and promising new experimental agents should have a profound impact on the treatment of patients with chronic hepatitis B virus (HBV) infection. However, certain management principles should remain unaltered. Recognizing the need for more urgent treatment in some individuals, being able to identify which patients require treatment and those who are most likely to respond to treatment, and selecting the optimal timing for treatment are clinical decisions that must continue to be addressed regardless of the antiviral agent 'of the month'. This review outlines general principles and provides a generic, timeless approach to the management of patients with chronic HBV infection.     

Export of intracellular HBsAg in chronic hepatitis B virus infection is related to viral replication.

Serum and liver HBsAg bear an inverse relation to each other during the evolution of chronic hepatitis B virus infection and the quantity of HBsAg in tissue rises gradually with time. In this study, intracellular and extracellular levels of HBsAg were measured by radioimmunoassay in primary culture of hepatocytes from 30 patients with chronic hepatitis B virus infection to determine a possible relationship with hepatitis B virus replication. Serum levels of HBsAg correlated with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.005, and tissue HBcAg, p less than 0.02) but inversely with tissue HBsAg (p less than 0.05). In similar fashion, in vitro export of HBsAg was also related to the presence of active viral replication markers (serum hepatitis B virus DNA, p less than 0.02, and tissue HBcAg, p less than 0.05) and negatively with tissue HBsAg (p less than 0.001). Export of HBeAg also correlated positively with markers of active viral replication (serum hepatitis B virus DNA, p less than 0.05 and tissue HBcAg, p less than 0.05). Further experiments indicated that intrahepatic pre-S1 and pre-S2 correlated closely with intrahepatic HBsAg, indicating that a failure to export HBsAg was unlikely to be attributable to deficient intracellular expression of pre-S1 or pre-S2. These data indicate that in vitro primary hepatocyte culture of hepatitis B virus-infected cells provides an accurate reflection of in vivo export of HBsAg and that this is closely related to the presence of active viral replication.     

Histological changes during clearance of chronic hepatitis B virus infection by adoptive immunity transfer

BACKGROUND: Serological clearance of hepatitis B surface antigen (HBsAg) has been described after reception of hepatitis B surface antibody positive marrow, via allogeneic bone marrow transplantation (BMT). Histological changes during the clearance of HBsAg are unknown. METHODS AND RESULTS: We described two chronic hepatitis B carriers (both hepatitis B e antigen negative), who cleared HBsAg after allogeneic bone marrow transplantation. Both received hepatitis B surface and core antibody positive human leucocyte antigen identical donors' marrow and had serological clearance of HBsAg 15 and 7 weeks after allogeneic BMT, respectively. Both events were preceded by hepatic flare. Both patients were also treated with famciclovir for the prevention of hepatitis B reactivation after BMT. Histological examination during the flare showed only mild necroinflammatory activity with multiple foci of confluent necrosis, associated with moderate lymphocytic infiltration. The majority of these lymphocytes were cluster of differentiation (CD) 8 positive. Using immunohistochemistry, there was no detectable hepatic expression of hepatitis B core antigen. However, HBsAg was positive, mainly in the area of confluent necrosis. Using in situ hybridization, hepatitis B virus (HBV) DNA was detected in the nucleus of 5% of hepatocytes, but not in the cytoplasm. CONCLUSIONS: At their last follow up, 22 and 16 months after BMT, the serum of both patients remained HBsAg negative, hepatitis B surface antibody positive and HBV-DNA negative by branched DNA assay.     

Interferon-gamma receptor expression in chronic hepatitis B virus infection.

It is known that interferon-gamma (IFN gamma) is not effective in inducing a sustained inhibition of HBV replication in patients with chronic HBV infection in contrast to interferon-alpha (IFN alpha). To determine whether this was related to IFN gamma receptor (IFN gamma-R) underexpression, binding characteristics of IFN gamma to peripheral blood lymphocytes were studied in chronic HBV infection using radioiodinated recombinant IFN gamma. Peripheral blood lymphocytes from patients with chronic HBV infection (n = 20), normal healthy controls (n = 12) and patients with non-viral related chronic liver disease expressed a similar number of IFN gamma-R (medians (ranges): 1891 (1581-2515); 1916 (1589-2441); 1893 (1692-2104) sites/cell, respectively, p = N.S.) with a similar dissociation constant (Kd approximately 0.7-2.7 nM). There was no correlation between IFN gamma-R expression and serum transaminase, serum HBsAg and HBV-DNA titres and liver histology. IFN alpha therapy in vivo also did not enhance IFN gamma-R expression (n = 3). There is therefore, no evidence from this data that IFN gamma-R is underexpressed in patients with chronic HBV infection to account for the difference in clinical response to these two forms of therapy.     

Asymptomatic chronic hepatitis B virus infection in northern India.

BACKGROUND: Chronic infection with hepatitis B virus (HBV) causes a spectrum of diseases ranging from asymptomatic infective state to cirrhosis and hepato-cellular carcinoma. The asymptomatic state has highly variable characteristics. METHODS: Sixty-one incidentally detected asymptomatic HBsAg-positive subjects (IDAHS), in whom HBsAg positivity persisted for > 6 months, were studied for liver biochemistry, HBeAg, anti HBe and HBV DNA levels (in HBeAg-negative subjects). Liver biopsy was done in 29 subjects and scored for histological activity index (HAI) and fibrosis using modified Knodell score. RESULTS: Thirteen (21%) subjects were HBeAg positive. The remaining 48 (79%) were positive for anti HBe, with HBV DNA level of> 105 copies/mL in 15 (31.2%). Transaminase elevation was more frequent in HBeAg-positive subjects (69%; p< 0.05) and in HBV DNA-positive (93%) than in non-replicative (27%) infection. Seroconverted (anti HBe-positive) individuals were a decade older than HBeAg-positive ones and most (93.7%) of them were> 20 years of age. Fifteen of 29 (51.3%) had HAI> 3, more frequently in those with raised ALT (68.4%; p< 0.05) than with normal ALT (20%), but there was no difference in relation to HBeAg status. CONCLUSIONS: Seroconversion to anti HBe was noted in individuals aged 20 years or more. Ongoing liver disease was noted in approximately half of IDAHS, suggesting that a considerable proportion of IDAHS have active infection. In HBeAg-negative subjects, transaminase estimation may be sufficient in planning therapy.     

Intrahepatic CD8+ T-lymphocyte response is important for therapy-induced viral clearance in chronic hepatitis B infection

BACKGROUND/AIMS: To determine which immune cells contribute to HBV-clearance during antiviral therapy, we performed a longitudinal analysis of intrahepatic immune cells during interferon-alpha therapy of chronic HBV-patients using the FNAB technique. METHODS: Twenty chronic HBeAg+-patients were treated with pegylated alpha-interferon combined with lamivudine or placebo for 52 weeks. FNAB and blood specimens were obtained at week 0, 2, 8 and 52. CD4+- and CD8+ T-lymphocytes, CD56+ cells, IFNgamma and granzyme B (GrB) were immunocytochemically quantified. RESULTS: The relative numbers of CD56+ cells and CD8+ T-lymphocytes were significantly higher in FNAB compared to blood at all time-points. Responders (n=9) exhibited significant increases in intrahepatic CD8+ and CD8+GrB+ lymphocytes, a small elevation in CD8+IFNgamma+ T-lymphocytes, no change in CD4+ T-lymphocytes, and a decrease in intrahepatic CD56+ cells during the first weeks of therapy. In non-responders (n=11) no significant changes in CD4+- and CD8+ T-lymphocytes and an increase in intrahepatic and CD56+ cells were observed during therapy. CONCLUSIONS: The intrahepatic CD8+ T-lymphocyte, but not the CD4+ T-lymphocyte or NK/NKT-cell response, is important for HBV clearance during interferon-alpha therapy, and the antiviral effect may be mediated by both cytolytic and non-cytolytic mechanisms.     

Virus-host interaction in chronic hepatitis B virus infection

The clearance of HBV-infected cells from the liver is probably dependent on an interplay between the interferon system and the cellular limb of the host immune response. Although the importance of the nucleocapsid proteins as targets for sensitized cytotoxic T cells is established in chronic HBV infection, further studies are needed during the early phase of acute HBV infection. The relative importance of pre S sequences as inducers and targets of the virus neutralizing humoral immune response is becoming established, but their precise place will await the development of in vitro models of hepadnavirus infection and precise definition of the mechanism of viral uptake. Our understanding of the mechanisms underlying the development of chronic HBV infection is still incomplete. When this occurs in adult life, deficient production of alpha interferon and suppression of the ability of the host to respond to interferon are probably important factors, and the role of suppression of the humoral response remains to be determined. In the neonate, specific suppression of the cell-mediated immune response, perhaps because of exposure to soluble HBe antigen or to modulating quantities of maternally derived antinucleocapsid antibodies at a time when the immune system is "immature," may be involved. In each of these postulated mechanisms the virus has neutralized one important host defense. Increasing the response rate to therapy with interferon or synthetic antiviral compounds will depend on identifying the cause in each patient and devising specific therapies to reverse the host-virus balance in favor of the host defenses.     

Viral replication in chronic hepatitis B virus infection

Digestive Diseases and Sciences -     

Effects of prednisolone/azathioprine in chronic hepatitis B viral infection.

Changes in markers of hepatitis B viral replication and standard liver function tests were studied in 30 patients with HBsAg positive chronic liver disease starting or stopping prednisolone/azathioprine therapy, and compared with those occurring in 15 patients who did not receive therapy. On stopping prednisolone/azathioprine, 10 out of 11 HBeAg positive patients and one out of three patients negative for HBeAg and anti-HBe, lost HBV-DNA polymerase activity (p less than 0.01), five lost HBeAg, three developed anti-HBe and HBsAg concentration decreased (p less than 0.01). Only one out of seven untreated HBeAg positive patients lost HBeAg and there were no significant changes in DNA polymerase activity. In the anti-HBe positive patients, 14 starting therapy and eight untreated, there were no significant changes in the markers of viral replication - although two patients developed DNA polymerase activity on high maintenance doses of prednisolone - but a significant decrease (p less than 0.05) in aspartate transaminase in the treated group. It is concluded that the cessation of prednisolone/azathioprine therapy in HBeAg positive patients will result in a reduction in viral replication. In anti-HBe positive patients such therapy may be beneficial.