Mechanisms of liver cell injury in acute and chronic hepatitis B

Elevation of 2',5'-oligoadenylate synthetase activity and HLA-I associated beta 2-microglobulin in response to recombinant interferon-gamma administration in chronic HBeAg-positive hepatitis

We have analyzed the immunomodulatory effect of 5 and 2 MU of recombinant interferon-gamma (rIFN-gamma) administered to 8 carriers of HBsAg with histologically proven chronic active liver disease. After the rIFN-gamma administration, T8 lymphocyte subsets showed a significant decrease (basal vs. 4 weeks, p less than 0.05) and T4/T8 ratios were higher than the basal values in 6/8 patients. Serum levels of the HLA class I-associated beta 2-microglobulin increased significantly in all patients within the first week of treatment, both with the high (p less than 0.01) and the low (p less than 0.05) rIFN-gamma dose. Then, differences between the two doses reached statistical significance (p less than 0.03). Similar results (p less than 0.05) were obtained by measuring the 2',5'-oligoadenylate (2-5A) synthetase activity, co-occurring with the decreases in HBV-DNA polymerase and HBV-DNA, although no differences were found between the two doses. In addition, levels of 2-5A synthetase correlated significantly with those of beta 2-microglobulin (r = 0.743, p less than 0.01). On the other hand, after the rIFN-gamma administration, all the patients had liver membrane antibodies (LMA) in their serum (p less than 0.05); only two patients (who were anti-HD positive) showed LMA at the end of the follow-up. rIFN-gamma has both antiviral and immunomodulatory effects in HBeAg carriers with chronic liver disease.

Clonal analysis of human T lymphocytes infiltrating the liver in chronic active hepatitis B and primary biliary cirrhosis

Human T lymphocytes infiltrating the liver in chronic active hepatitis B (CAH-B) and primary biliary cirrhosis were isolated from liver biopsy cores, cloned by limiting dilution technique and expanded in vitro. Phenotypic and functional analysis demonstrates that this tissue infiltrate represents a heterogeneous cell population. However, when compared to peripheral blood lymphocytes of the same patients, a marked enrichment for T8+ cytotoxic T cells was found to exist at a local site in both types of chronic liver disease. These data provide support for the notion that liver cell injury in CAH-B and PBC may be mediated by a common immunologic mechanism likely executed by cells of the T lineage.

Anti-HBs- and anti-HBc-containing plasma cells in livers of patients with chronic type B hepatitis

Plasma cells are commonly found in liver biopsies in acute and chronic type B hepatitis. Their specificities have not hitherto been examined. In this study, anti-HBs and anti-HBc were looked for in paraffin sections of liver biopsies from 16 patients with chronic type B hepatitis, all seropositive for HBeAg. The technique used was a reversed immunoperoxidase procedure in which purified antigens were applied to sections and detected by means of a further layer of the appropriate monoclonal antibody. Small numbers of plasma cells stained for anti-HBs and anti-HBc in 6 and 4 of 16 biopsies, respectively. Some plasma cells appeared to contain neither antibody. The two antibodies were detected together in only one biopsy. In spite of the small numbers of positive cells as revealed by the technique used, antiviral antibodies produced locally by plasma cells may play a part in the pathogenesis of viral hepatitis.

Virus-triggered immune suppression in mice caused by virus-specific cytotoxic T cells

Normal mice infected with 10(5) infectious doses of lymphocytic choriomeningitis virus (LCMV, WE isolate) generated a reduced or no T cell-independent IgM and/or T cell-dependent IgG response to a subsequent vesicular stomatitis virus Indiana (VSV-IND) injection; this transient immune suppression lasted for weeks to months. Connatally infected LCMV-carrier mice or acutely infected T cell-deficient nude mice had normal anti-VSV IgM and IgG or IgM responses respectively. LCMV-infected nude mice transfused with helper cell-depleted LCMV-specific immune spleen cells were immunosuppressed. Normal mice infected with LCMV but treated with a rat anti-CD8 mAb (that had been shown previously to eliminate cytotoxic T cells in vivo) and then infected with VSV exhibited a normal anti-VSV IgM and IgG response. Since no IFN-alpha or -beta was detected on, or after, day 6 of LCMV infection, neither LCMV alone, nor IFN induced by it caused the observed immune suppression; the presented evidence suggests that LCMV-immune CD8+ T cells were responsible for it. It is conceivable that a similar pathogenesis where virus-specific cytotoxic T cells may destroy virus-infected cells essentially involved in an immune response (APC, T helper cells, etc.) may be involved in other virally triggered immune suppression or in AIDS.

Interaction of woodchuck hepatitis virus surface antigen with hepatocyte plasma membrane in woodchuck chronic hepatitis

The extent of association between woodchuck hepatitis virus surface antigen and host hepatocyte plasma membrane in chronic hepatitis was studied. Purified membranes containing the antigen were treated with various agents which perturb plasma membrane constituents to elute woodchuck hepatitis virus surface antigen. The products from disrupted membranes were analyzed by sedimentation in sucrose gradients and tested to identify the antigen reactivity. The results indicated that membrane-bound woodchuck hepatitis virus surface antigen was partially released by 4 M potassium chloride, potassium thiocyanate and guanidine, 6 M urea or 0.1 N sodium hydroxide (pH 13.5), but not in the presence of low concentrations of these reagents or by 10% 2-mercaptoethanol and 1% sodium dodecyl sulfate. No more than 15% of the total membrane-associated woodchuck hepatitis virus surface antigen was eluted by 0.1 N NaOH, which was found to be the most effective eluent among tested agents at the antigen removal. The remaining woodchuck hepatitis virus surface antigen was resistant to further extraction with sodium hydroxide, as expected for an integral membrane protein. Treatment of the infected membranes with 1% Triton X-100 or 50 mM deoxycholic acid, that solubilize the membrane lipid bilayer releasing most of the integral membrane proteins, resulted in the sedimentation of almost all detectable woodchuck hepatitis virus surface antigen reactivity with the detergent-insoluble membrane residues, suggesting a firm interaction of the antigen with the plasma membrane matrix.(ABSTRACT TRUNCATED AT 250 WORDS)

An acquired immune suppression in mice caused by infection with lymphocytic choriomeningitis virus

A murine model of virally induced acquired immunodeficiency was analyzed in mice. The effect of systemic infection with various isolates of lymphocytic choriomeningitis virus (LCMV) on the capacity of mice to mount a T cell-independent IgM and a T cell-dependent IgG neutralizing antibody response against a subsequent infection with vesicular stomatitis virus (VSV) was analyzed. DBA/2 mice infected with the LCMV-WE isolate were impaired in their IgM and IgG responses to VSV. Immune suppression was not caused by interferons inhibiting proper VSV antigen expression, since responses to inactivated VSV were also suppressed. The higher the dose of the LCMV and the lower the dose of the challenging VSV infection the more drastic was the apparent lack of immune responsiveness and the longer it lasted. Kinetics of induction of suppression of the T cell-independent IgM responses closely followed that of a normal cytotoxic T cell response to LCMV-WE, starting on day 6 and reaching maximal levels by day 8 to 10. The T cell-dependent IgG response to VSV was suppressed with a kinetics that was shifted by about 6 days when compared with suppression of IgM responses, i.e. LCMV infection on the same day or before (but not after) VSV infection led to suppression of IgG responses that are usually first detected by day 6-7 after initiation of the VSV infection. Severity and duration of immunosuppressiveness depended upon the LCMV isolate and the mouse strain used: LCMV-WE and LCMV-Docile were most, whereas LCMV-Armstrong was in general least immunosuppressive. Antibody responses to VSV-NJ seemed to be more subject to LCMV-induced immune suppression than VSV-IND-specific responses. Mouse strains differed considerably with respect to extent of suppression, dependent upon both major histocompatibility genes (MHC) and non-MHC genes. DBA and Swiss type mice were generally more susceptible than C57BL and CBA mice, and H-2q and H-2k seemed to be more susceptible than H-2b or H-2d mice. Mice infected with LCMV-WE showed signs of acquired immunodeficiency diseases since they were more susceptible to superinfection with VSV and developed paralytic disease and tended to die from VSV infection. Since LCMV is basically a noncytopathic virus, this murine model of virally induced immune suppression may serve to analyze immune pathogenesis of virus-induced acquired immunodeficiency.

Prospective study of cellular immunity to hepatitis-B-virus antigens from the early incubation phase of acute hepatitis B

Cellular immunity to hepatitis-B-virus (HBV) antigens was followed prospectively in five patients who were identified in the early incubation phase of acute HBV infection, between 30 and 70 days before the onset of liver damage. Cellular immunity to pre-S antigens was the first detectable immune response, appearing 30 days before the first rise in serum aminotransferases in every case. T-cell sensitisation to HBcAg followed, with IgM anti-HBc appearing 10 days later. A cellular immune response to HBsAg was the last to appear, 10 days before the onset of liver damage. These cellular immune responses are the earliest host responses to the virus infection and could be critical in initiating and directing the processes of liver damage and viral clearance.

T cell-mediated hepatitis in mice infected with lymphocytic choriomeningitis virus. Liver cell destruction by H-2 class I-restricted virus-specific cytotoxic T cells as a physiological correlate of the 51Cr-release assay?

A model for immunologically T cell-mediated hepatitis was established in mice infected with lymphocytic choriomeningitis virus (LCMV). The severity of hepatitis was monitored histologically and by determination of changes in serum levels of the enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), and alkaline phosphatase (AP). Kinetics of histological disease manifestations, increases of liver enzyme levels in the serum, and cytotoxic T cell activities in livers and spleens all correlated and were dependent upon several parameters: LCMV-isolate; LCMV-WE caused extensive hepatitis, LCMV-Armstrong virtually none. Virus dose. Route of infection; i.v. or i.p. infection caused hepatitis, whereas infection into the footpad did not. The general genetic background of the murine host; of the strains tested, Swiss mice and A-strain mice were more susceptible than C57BL or CBA mice; BALB/c and DBA/2 mice were least susceptible. The degree of immunocompetence of the murine host; T cell deficient nu/nu mice never developed hepatitis, whereas nu/+ or +/+ mice always did. B cell-depleted anti-IgM-treated mice developed immune-mediated hepatitis comparably or even more extensively than control mice. Local cytotoxic T cell activity; mononuclear cells isolated from livers during the period of overt hepatitis were two to five times more active than equal numbers of spleen cells. Adoptive transfer of nylon wool-nonadherent anti-Thy-1.2 and anti-Lyt-2 plus C-sensitive, anti-L3T4 plus C-resistant lymphocytes into irradiated mice preinfected with LCMV-WE caused a rapid time- and dose-dependent linear increase of serum enzyme levels. This increase was caused by adoptive transfer of lymphocytes if immune cell donors and recipient mice shared class I, but not when they shared class II histocompatibility antigens. The donor cell dose-dependent increase of these enzymes was first measurable 6-18 h after transfer with 2 X 10(8) cells or 3 X 10(6) cells, respectively. The time-dependent increase caused by the adoptive transfer of 1-2 X 10(8) cells was strictly linear during a period of up to 25-40 h. These results indicate single-hit kinetics of liver cell death and suggest that effector T cells destroy infected liver cells via direct contact rather than via soluble toxic mediators. The results may represent the best in vivo correlate of the in vitro 51Cr-release assay that has been analyzed so far, and strongly support the view that antiviral cytotoxic T cells are directly cytolytic in vivo.(ABSTRACT TRUNCATED AT 400 WORDS)

Preparation and characterization of human monoclonal antibodies directed against the hepatitis B virus surface antigen

The hepatitis B surface antigen (HBsAg) is highly immunogenic and induces an antibody response which is protective in vivo against hepatitis B virus (HBV) infection. Human monoclonal antibodies specific for HBsAg were produced, which could have potential therapeutic applications. Lymphocytes obtained from a vaccinated donor were stimulated in vitro and fused with the human myeloma cell line GM 4672, and eight hybridomas were obtained. Three of these clones, which reacted in an ELISA against the HBsAg vaccine, were expanded, subcloned and further analyzed. The subclones E7C2, C4C10, and D5B2 were able to bind to different HBsAg preparations, which express various subtypes, and recognized the major HBsAg peptides in Western blot analysis. Cross-inhibition experiments showed that E7C2, C4C10 and D5B2 are directed against the same epitope and have an affinity constant ranging from 5 X 10(7) to 3.3 X 10(9) M. Furthermore, these antibodies stained the surface and cytoplasm of the HBsAg-secreting cell lines PLC/PRF/5 and 4.10. The production of immunoglobulins varies from 0.3 to 1.3 micrograms/ml/10(6) and has remained stable over a period of 8 months. These human monoclonal antibodies, which appear to be directed against an antigenic determinant common to all HBsAg subtypes, could be useful in the study of HBV-related liver diseases as well as in their diagnosis and experimental therapy.

Interferons in the treatment of chronic hepatitis B virus infection

Hepatitis B virus offers several properties that may help to determine how antiviral substances, such as interferon, work. A description of the phases of chronic hepatitis B virus infection is presented, as well as the rationale for interferon therapy as treatment.

Hepatitis B virus DNA in leukocytes of patients with hepatitis B virus-associated liver diseases

In order to determine the relationship between hepatitis B virus (HBV) infection of human white blood cells and different forms of HBV-associated liver diseases, we tested for HBV DNA in the sera and leukocytes of 11 healthy individuals without any serological markers of HBV infection and 91 patients with HBV infection and other gastrointestinal and urinary diseases by dot and Southern blot hybridization. HBV DNA was found in leukocytes of chronic HBV carriers, in acute and chronic hepatitis, and in patients with liver cirrhosis and hepatocellular carcinoma. Between 27 and 50% of individuals in different categories of patients examined were positive for leukocyte HBV DNA. HBV DNA was also detected in the sera of some of these patients but was absent in others. Serum HBV DNA-positive rates seemed to be highest in hepatitis B e antigen-positive asymptomatic carriers (8/10, 80%), and tended to drop to lower levels as the disease progressed to liver cirrhosis (0/8) while leukocyte HBV DNA-positive rates were highest in patients with cirrhosis (4/8, 50%). The results also show that in individuals who were serologically negative for hepatitis B surface antigen (HBsAg) and positive for antibodies to HBsAg and/or HBcAg, HBV DNA was absent in most of the sera (27/28, 96%) but it was present in leukocytes of some of these patients (7/28, 25%). In control experiments with 11 healthy individual, HBV DNA was not detected in either sera or leukocytes. In all the cases with leukocyte HBV DNA, the HBV DNA molecules were present in free forms with discrete sizes. The exceptions were a case of liver cirrhosis and a case of chronic hepatitis with possible HBV sequence integration into high molecular weight cellular DNA. Since HBV does infect human leukocytes, it may perhaps interfere with the immunological functions of the white blood cells, and thus play an important role in the pathogenesis of HBV-induced liver disease.

In vitro effect of lymphoblastoid alpha-interferon on subpopulations of effector cells mediating cytotoxicity for autologous hepatocytes in hepatitis B and non-A, non-B

Controlled clinical trials are currently under way to assess the efficacy of interferon (IFN) in hepatitis B virus (HBV) infection. In the present study, T-enriched and non-T-enriched lymphocytes from six patients with acute and six patients with chronic HBV infection were cocultured with autologous liver cells with and without alpha-IFN (lymphoblastoid) at a concentration of 1000 U/ml of culture medium, in an 18 h cytotoxicity assay. IFN produced a significant enhancement of non-T-cell cytotoxicity in patients with acute and chronic HBV infection, from 34.3 +/- 19.6% to 60.0 +/- 11.2%, P less than 0.03, and from 41.2 +/- 17.2% to 65.5 +/- 9.8%, P less than 0.01, respectively. In contrast, no significant effect was observed on T cell-mediated cytotoxicity in either group of patients. The in vitro effect of alpha-IFN was also evaluated in four patients who developed chronic non-A, non-B hepatitis following blood transfusion, but no significant stimulatory effect was noted on either T- or non-T cell cytotoxicity. Similarly, no significant increase was observed in control subjects. The significant enhancement of non-T cell cytotoxicity, but not of T-cell cytotoxicity, for autologous hepatocytes in HBV infection suggests that alpha-IFN produces a selective stimulatory effect on non-T cells. The absence of a similar effect in patients with chronic non-A, non-B hepatitis and control subjects suggests that HBV infection alters the susceptibility of hepatocytes to IFN-stimulated non-T cell damage.

Immunopathological mechanisms of liver cell injury in chronic hepatitis B virus infection

It is generally accepted that the hepatitis B virus is not cytopathic and that liver cell damage in chronic HBV infection is dependent on the host's immune response directed at viral and self-antigens on the surface of infected hepatocytes. In recent years there have been some advances in the understanding of both the viral antigen display on hepatocytes and the resultant host response. Using fluoresceinated polyclonal and monoclonal antibodies to HBV antigens, HBcAg has been identified as the major viral product expressed on the surface of liver cells isolated from patients with chronic HBV infection. In these patients, both T and non-T cells from peripheral blood have been shown to be cytotoxic to autologous hepatocytes. Blocking studies using polyclonal anti-HBs and anti-HBc antibodies indicate that HBcAg, but not HBsAg, is an important target antigen for T-cell attack, and this has recently been confirmed using monoclonal reagents. The non-T cell cytotoxicity appears to be directed at auto-antigens in a liver membrane lipoprotein complex (LSP), probably through an antibody-dependent (ADCC) mechanism. T-cell bypass mechanisms could be responsible for the production of autoantibodies to these normal membrane components. Both these mechanisms of cytolysis are found, most often, in patients with active viral replication in the HBeAg-positive phase of chronic HBV infection. This is presumably because hepatocytes containing free HBV-DNA and expressing HBcAg on their surface will be most susceptible to T-cell attack, while those with integrated HBV-DNA only express HBsAg and are relatively protected.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of HBV replication and delta agent superinfection on T cell subsets and killer (Leu 7+) in chronic hepatitis B virus infection

Peripheral blood T-lymphocyte subsets and cells reacting for Leu 7 antigen, which identifies a subset of killer and natural killer cells, have been examined in 32 patients chronically infected by the hepatitis B or D viruses (HBV, HDV) and in 28 normal subjects. The T8+ lymphocytes were increased and the T4/T8 ratio was decreased in patients with HBV replication (identified by the presence of HBcAg in liver and HBV-DNA in serum) and in patients with HDV infection (HDAg in liver). These patients had more active liver disease than patients without evidence of viral replication, B or D, who showed normal lymphocyte counts. Leu 7+ lymphocytes were also increased in patients with viral replication and active disease and correlated positively with alaninaminotransferase serum levels. These observations suggest the participation of both T8+ and Leu7+ cells in the pathogenesis of liver cell injury in HBsAg-positive chronic liver disease.

Altered natural history of hepatitis B in homosexual males--a reflection of altered immune responsiveness?

We suggest that subtle alterations in T-cell functions in male homosexuals makes them more likely to have silent anicteric hepatitis B infection, and perhaps more likely to become chronic carriers with significant chronic liver disease. This immunodeficiency might also explain why they respond less favourably to antiviral therapy. In future trials of antiviral therapy homosexual males should be randomised separately. Further studies of the immunomodulatory effects of new and existing agents will be of value in designing drug regimes particularly suited to the treatment of homosexual HBV carriers.

Acute and chronic changes in the microcirculation of the liver in inbred strains of mice following infection with mouse hepatitis virus type 3

The acute and chronic effects of mouse hepatitis virus type 3 on the microcirculation of the liver in both semisusceptible C3HeB/FeJ and fully resistant A/J mice were studied. In the C3HeB/FeJ mice, abnormalities of microcirculatory flow were noted as early as 12 hr after infection and by 24 hr, localized avascular foci appeared. Disturbances were characterized by granular blood flow, sinusoidal microthrombi, distortion of sinusoids by edematous hepatocytes and necrotic lesions. Following the acute infection, Day 10, two patterns of chronic disease were observed. Eighty percent of the mice developed chronic granulomatous hepatitis whereas in the remaining 20% a more severe chronic aggressive hepatitis was observed which was characterized by ongoing hepatocellular necrosis and a marked mononuclear cell infiltrate. In both cases, in vivo microcirculatory abnormalities were found predominantly around visible lesions. Onset of the microcirculatory abnormalities was found to be concomitant with a rise in monocyte related procoagulant activity. Procoagulant activity rose acutely and remained elevated throughout the chronic phase but was higher in animals with severe disease. In contrast to the above, normal blood flow and histology were seen in the resistant A/J mice at all times following infection, and procoagulant activity remained at basal levels despite active viral replication as demonstrated by immunofluorescence studies and recovery of infectious virus. These observations suggest a role for monocyte procoagulant activity in the development of microcirculatory abnormalities following mouse hepatitis virus type 3 infection which may be important in the pathogenesis of the disease.

Different mechanisms responsible for in vitro cell-mediated cytotoxicity to autologous hepatocytes in children with autoimmune and HBsAg-positive chronic liver disease

To investigate mechanisms of hepatocyte injury, lymphocytes from 41 children with chronic liver disease were incubated with autologous liver cells in a microcytotoxicity assay. Cytotoxicity was significantly increased in 18 of 25 patients with chronic hepatitis B virus (HBV) infection, in five of nine with "autoimmune" chronic active hepatitis (CAH), and in only one of seven with histologically inactive liver disorders. There was a good correlation between cytotoxicity and biochemical and histologic markers of disease activity in children with autoimmune CAH, whereas in HBsAg-positive disease a positive correlation was found only with serum alanine aminotransferase (SGPT). Children with autoimmune CAH receiving steroid treatment had normal cytotoxicity, whereas increased values were found in two of three HBsAg-positive patients receiving prednisolone. Fractionation studies revealed that non-T cells were cytotoxic in both autoimmune and HBcAg-positive chronic liver disease. T cell cytotoxicity was exclusively found in children with chronic HBV infection, particularly with HBc antigenemia. Blocking experiments showed that T-lymphocytes from HBsAg-positive children reacted with HBV core antigen on the hepatocyte surface. Non-T cells were directed against hepatocyte membrane antigens in both HBsAg-positive and HbsAg-negative children. These results suggest that different immune mechanisms of liver damage are involved in autoimmune and HBsAg-positive chronic liver disease.

Studies by electron microscopy on the assembly of duck hepatitis B virus in the liver

Liver specimens from 1-day-old ducklings infected in ovo with maternally transmitted duck hepatitis B virus (DHBV) were examined by electron microscopy. Complete and incomplete DHBV particles were located within hypertrophied cisternae of the endoplasmic reticulum of the hepatocytes. The complete viral particles found intracellularly have inner cores with a diameter ranging from 35 to 37.5 nm and an outer coat or envelope. The whole particle measures approximately 45-65 nm in diameter. Naked core particles were located in the nuclei, free in the cytoplasm, and also near or on the cisternal membrane of the endoplasmic reticulum on the cytoplasmic face. Duck hepatitis B virions appear to share morphological characteristics with the viral coat and core of human hepatitis B virus (HBV). Electron microscopy suggested that the core particles of DHBV migrate from the nucleus into the cytoplasm through the nuclear pores. The complete viral particles are probably formed by protrusion of the core particles through the endoplasmic reticulum and by simultaneous encapsulation with a coat derived from the endoplasmic reticulum.

Immunoglobulin-containing plasma cells in acute hepatitis

Imunoglobulin(Ig)-containing plasma cells in human liver were investigated in different aetiological and histological forms of acute hepatitis. Liver specimens from 93 patients with acute hepatitis (A, B, non-A, non-B and drug-induced) were studied by conventional microscopy and by immunoperoxidase staining for IgG, IgA and IgM in paraffin sections. Plasma cells were found in 78 of 93 specimens and Ig-containing cells in 75. IgG-containing cells were significantly more abundant in acute hepatitis with bridging necrosis than in other forms (p less than 0.01), and there were more IgA-containing cells than in the classical and periportal forms (p less than 0.05). IgG-containing cells were more numerous in acute hepatitis with periportal or panacinar necrosis than in the classical form (p less than 0.05). IgG- and IgA-containing cells were less abundant in drug-induced hepatitis than in viral hepatitis (p less than 0.05). Among the viral groups the largest number of IgG-containing cells was found in non-A, non-B hepatitis, while IgA-containing cells were most abundant in type A. These differences were not statistically significant. IgM-containing cells were very scanty in all groups studied. It is concluded that Ig-producing plasma cells are common in acute viral hepatitis and presumably play a part in antibody-dependent immune reactions in this disease.

Radioimmunometric assay for hepatitis B surface antigen on the surface of infected cells

It has been difficult to differentiate hepatitis B surface antigen (HBsAg) on the cell surface from intracellular or intramembranous HBsAg that is not exposed to the host immune response. We describe here a radioimmunometric assay for HBsAg on the cell surface using HBsAg producing hepatocellular carcinoma cell lines and fibroblasts transfected with cloned hepatitis B virus DNA as models. The assay is sensitive, specific, simple and takes approximately 1 1/2 h. The procedure may be modified to compare quantitatively cell surface with intracellular HBsAg and to demonstrate other cell associated hepatitis B virus antigens such as HBcAg and HBeAg.

Detection of anti-HBc IgM following prednisone treatment in patients with chronic active hepatitis B virus infection

The effect of a short course of prednisone therapy on serum IgM type antibody to the hepatitis B core antigen (anti-HBc IgM) was studied in 14 male patients with chronic active type B hepatitis. Eleven patients (78.5%) became positive for serum anti-HBc IgM either during or shortly after prednisone withdrawal. Detection of anti-HBc IgM correlated with an increase in hepatitis B virus specific DNA-polymerase activity and was followed by a rise in serum transaminase levels. Six patients with histologic evidence of cirrhosis developed anti-HBc IgM which lasted six or more months after prednisone therapy and had a rapid onset of hepatic decompensation manifested by encephalopathy with ascites and/or variceal bleeding. In 17 untreated chronic active type B hepatitis patients who served as controls, anti-HBc IgM was detected at low levels in only a single serum sample from each of two patients during the same observation period.