Hepatitis B virus DNA (HBV-DNA) in anti-HBe positive sera

HBV-DNA measured by the spot hybridization technique, was found in the sera of 28 of 106 (26.4%) anti-HBe positive carriers of HBsAg. Dane particle-associated HBeAg, HBcAg and HBV-specific DNA-polymerase activity were found in the sera of nine (8.5%), five (4.7%) and two (1.9%) of these patients, respectively. All carriers with serum HBV-DNA had chronic liver disease and 18 had intrahepatic delta-Ag and serum anti-delta at titers higher than 1/5000. Intrahepatic HBcAg was detected in the nuclei of 90% of delta negative individuals; 50% of them also had cytoplasmic fluorescence. Only two of the 18 patients with intrahepatic delta-Ag (11%) had HBcAg in the liver. Viral nucleic acid was not found in the sera of 15 other patients with chronic hepatitis, seven of whom had intrahepatic delta-Ag. Serum HBV-DNA was also negative in the remaining 63 symptomless carriers of HBsAg lacking markers of delta infection. Interestingly, although DNA-polymerase negative, some sera gave autoradiographic spots of high optical density. HBV-DNA was detected in them at concentrations typical of sera which are usually both DNA-polymerase and HBeAg positive. Detection of HBV-DNA in serum represents the most direct and sensitive in vitro assay for assessing HBV infectivity and characterizes HBsAg carriers with HBV-related liver damage and ongoing HBV replication independently from the state of HBeAg/anti-HBe system. In the Mediterranean area, the majority of anti-HBe positive carriers with serum HBV-DNA have chronic liver disease and delta infection.

Transmission of the hepatitis B virus-associated delta agent to the eastern woodchuck

delta agent of human origin was inoculated into four woodchucks chronically infected with woodchuck hepatitis virus (WHV). The animals developed delta infections with serologic patterns similar to those previously observed in human and chimpanzee infections. delta antigen was detected transiently in serum and liver and was followed by seroconversion to anti-delta antibody. Analogous to the chimpanzee model of delta infection, serum and hepatocyte markers of WHV were suppressed in the woodchuck during acute delta infection. The suppression of WHV DNA in serum was evident only during the time of delta-antigen positivity, while the inhibition of other WHV markers was more protracted. The delta antigen in woodchuck sera circulated as an internal component of a particle similar in size to the human delta particle (36-nm diameter) and was encapsidated by the woodchuck hepatitis virus surface antigen; delta antigen from infected woodchuck and chimpanzee livers had similar biophysical properties. Histologic analysis showed that experimental delta infection is associated with a transient acute hepatitis in woodchucks and loss of hepatocytes carrying WHV antigens. The lesions differed from the conspicuous hepatitis associated with reappearance of WHV replication. Hepatitis B-like viruses, therefore, appear to provide the requisite helper functions for delta replication and the woodchuck represents a useful model for study of the virology and pathology of the delta agent.

Delta hepatitis agent: structural and antigenic properties of the delta-associated particle

Delta agent (delta) was serially passaged to a second and third hepatitis B surface antigen (HBsAg) carrier chimpanzee, using as inoculum the peak delta antigen (delta Ag) serum of an animal previously infected with human serum. The characteristics of serially transmitted delta Ag were similar to those described in first-passage animals. It was consistently detected before the development of anti-delta, in association with a 35- to 37-nm subpopulation of HBsAg particles and a unique low-molecular-weight (5.5 X 10(5)) RNA. RNase susceptibility of the delta-associated RNA and release of delta Ag activity upon treatment of delta-associated particles with detergent revealed that this particle is organized into a virion-like form with the RNA and delta Ag as internal components within a coat of HBsAg. Surface determinants of the delta-associated particle other than HBsAg were not detected by radioimmunoprecipitation experiments, using sera of humans and chimpanzees convalescent from delta hepatitis. The HBsAg-associated particle is the "candidate agent" of delta hepatitis.

Complexes of hepatitis B surface antigen and immunoglobulin M in the sera of patients with hepatitis B virus infection

Hepatitis B surface antigen (HBsAg) bound to immunoglobulin M (IgM) was detected in sera of HBsAg carriers by a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. Isopycnic banding and rate-zonal sedimentation have shown that the reaction is related to particulate forms of the HBsAg complexed with IgM. The binding of IgM possibly occurred because of a selective affinity of these molecules to the surface of HBsAg particles. HBsAg/IgM was found transiently in 24 of 25 (96%) patients with acute self-limited hepatitis B and persistently in 6 of 25 patients whose acute hepatitis B progressed to chronicity. It was also found in 20 of 39 (51%) chronic HBsAg carriers with inactive and asymptomatic infection. The HBsAg/IgM phenomenon is not dependent on replication of hepatitis B virions; its persistence in patients with acute hepatitis B may provide complementary evidence of transition of the infection to chronicity.

Delta hepatitis in inapparent carriers of hepatitis B surface antigen. A disease simulating acute hepatitis B progressive to chronicity

Infection with the hepatitis B surface antigen (HBsAg)-associated delta agent (delta) was determined in a series of Italian patients with a diagnosis of acute hepatitis B (HBsAg-positive) progressive to chronicity. Twenty-two of 27 (81%) and 12 of 18 (67%) patients collected, respectively, in Naples and Cagliari, where delta is highly endemic, developed immunoglobulin M antibody to delta and/or rising titers of immunoglobulin G anti-delta during the initial acute phase of the disease. In each of them, anti-delta increased to a high-titered plateau indicative of chronic delta infection. Delta markers were found in none of the 13 patients collected in Siena, where the prevalence of delta infection is low. The great majority of the patients with anti-delta and a progressive form of HBsAg-positive hepatitis lacked the IgM antibody to hepatitis B core antigen. They were presumably unrecognized carriers of HBsAg who became infected by delta and developed hepatitis induced by this agent. In areas where delta is endemic, it may represent the true cause of seemingly type B hepatitis progressing to chronic HBsAg-positive liver disease.

Cytoplasmic tubular structures in liver of HBsAg carrier chimpanzees infected with delta agent and comparison with cytoplasmic structures in non-A, non-B hepatitis

Electron microscopic observations were carried out on five HBsAg carrier chimpanzees infected with delta (delta) agent and two chimpanzees infected with human non-A, non-B hepatitis. The cytoplasmic tubular structures, which have been recognized in the liver of chimpanzees infected with human non-A, non-B hepatitis, were found also in the liver of HBsAg carrier chimpanzees infected with delta agent. The quantity of the cytoplasmic structures in serial studies was associated with SGPT elevation rather than with expression of delta antigen in sera and liver tissues. This indicates that the cytoplasmic structures reflect a pathologic change of the hepatocytes in chimpanzees infected with delta agent or human non-A, non-B hepatitis. These and other similarities between the two agents suggest a similar nature.

HBsAg/IgM complexes in serum of HBsAg carriers: partial characterization and clinical significance

HBsAg bound to IgM was detected in serum of HBsAg carriers with a radioimmunoassay based on selective absorption of the immunoglobulin on a solid phase coated with antiserum to human IgM. High titers of HBsAg/IgM were found in sera with the highest HBsAg binding capacity of polymerized human serum albumin (poly-HSA) and of C1q. These findings and the inhibition of HBsAg/IgM reaction by addition of purified poly-HSA suggest that the IgM component of the complex might bind to poly-HSA fixed on to HBsAg particles and possibly represent antibody to the modified plasma protein. HBsAg/IgM was detected in 95 (87%) patients with acute HBsAg positive hepatitis during the acute phase of infection and persisted after the fourth week only in patients who developed chronic liver disease. HBsAg/IgM were detected in one out of 15 carriers of the HBsAg with superimposed Non B hepatitis. HBsAg/IgM were also present in 76% to 100% of sera from chronic carriers without any relation to the extent of viral replication and to presence of severity of liver disease. Persistence of HBsAg/IgM in patients with acute hepatitis B may provide a useful tool to predict transition of HBV infection to chronicity.

Chronic hepatitis in carriers of hepatitis B surface antigen, with intrahepatic expression of the delta antigen. An active and progressive disease unresponsive to immunosuppressive treatment

To assess the characteristics of chronic hepatitis in hepatitis B surface antigen (HBsAg) carriers with intrahepatic delta antigen, the hepatic histologic findings of 137 patients were reviewed; 101 patients were followed for 2 to 6 years. The predominant liver disease was chronic active hepatitis in 93 patients or cirrhosis in 32; minor forms of chronic persistent or lobular hepatitis were seen in 12 patients. Eight of the 26 patients with an initial diagnosis of cirrhosis died during the follow-up period. Cirrhosis developed in 31 of 75 patients (41%) without nodular regeneration seen in the first biopsy specimen; 5 of these patients died. Treatment with prednisone or azathioprine did not induce histologic amelioration of delta hepatitis or prevent cirrhosis. Chronic HBsAg hepatitis with intrahepatic expression of the delta antigen is an active, progressive disease unresponsive to conventional immunosuppressive treatment.

Hepatitis B virus replication and clinical outcome in carriers of HBsAg. Perspectives of treatment with DNA inhibitors

HBV-DNA was measured by the spot hybridization technique in serial serum samples obtained from 47 HBsAg carriers followed up for a mean of 4 years. The levels of HBV-DNA were compared to the conventional HBV serology and immunopathology to determine the relation of active HBV replication to the outcome of hepatitis and the suitability of Italian HBsAg carriers for treatment with DNA inhibitors. HBV-DNA was found in 26 carriers (53%) and persisted with comparable serum levels in 24 of them throughout the follow up. The occurrence rate of an unfavorable outcome as determined by histological evidence of cirrhosis was 6% versus 44% (p less than 0.01) in carriers with active viral infection (greater than 1 ng/ml of HBV-DNA) and in patients with absent or low levels of viral DNA (less than 1 pg/ml), respectively. Progression of the liver disease could not be predicted on the basis of active HBV replication and was presumably related to factors other than synthesis of HBV. In many patients with inactive viral infection a primary pathogenic factor was the HBV-associated delta, an agent with a putative RNA genome against which DNA inhibitors have no rationale and possibly no effects. The majority of Italian carriers do not appear suitable for treatment with DNA inhibitors and they should be considered for a different therapy.

Complexes between HBsAg and IgM in serum of patients with acute hepatitis

HBsAg bound to IgM was measured in the serum of HBsAg carriers with acute hepatitis using a radioimmunoassay based on selective absorption of IgM on solid phase coated with antiserum to human IgM. HBsAg/IgM was detected in 94 (100%) patients with acute type B hepatitis during the acute phase of infection and persisted after the fourth week only in 13 of them, who developed chronic liver disease. HBsAg/IgM was detected only in 1 patient out of 15 carriers of the HBsAg with superimposed non-B hepatitis. No activity was found in serum of 20 patients with acute HBsAg-negative hepatitis. The nature of the IgM component of the complex is uncertain, however, blocking experiments of the HBsAg/IgM reaction with polymerized human albumin suggest that the IgM component of the complex might represent antibody to the denatured protein. Persistent HBsAg/IgM complex detection in patients with acute type B hepatitis provides a useful tool to predict transition of HBV infection to chronicity. Its absence in patients with acute HBsAg-positive hepatitis is indicative of non-B hepatitis in chronic carriers of the HBsAg.

Hepatitis B virus DNA in the sera of HBsAg carriers: a marker of active hepatitis B virus replication in the liver

Sera and liver biopsies from 30 Italian patients, carriers of HBsAg for at least 3 years, were examined for markers of hepatitis B virus (HBV) infection by serological assays and immunofluorescence. Biopsies were analyzed for HBcAg, HBsAg, and delta antigen by immunofluorescence; sera were assayed for HBsAg/anti-HBs, HBcAg/anti-HBc, HBeAg/anti-HBe, delta/anti-delta, HBV-specific DNA polymerase activity and the presence of HBV DNA. HBcAg, HBeAg, and DNA polymerase tests were positive in the sera of 71, 86, and 57%, respectively, of carriers with intrahepatic HBcAg. HBV DNA was detected in 100% of patients expressing HBcAg in the liver with a strong correlation between the concentration of serum DNA and the intensity of HBcAg immunofluorescence in the liver. HBV DNA was detected in the sera of 63% of carriers with intrahepatic delta where the other markers of HBV replication (HBeAg, DNA polymerase) were undetectable. The assay for serum HBV DNA appears to be an excellent noninvasive method for detecting active replication of HBV in HBsAg carriers.

The delta agent: HBsAg particles with delta antigen and RNA in the serum of an HBV carrier

The hepatitis B virus-associated delta antigen was detected in the serum of a young female drug addict with acute hepatitis and a previous history of hepatitis B surface antigen carrier. Delta antigen was associated with a 35- to 37-nm subpopulation of hepatitis B surface antigen particles which banded at a density of 1.25 gm per cm3 of CsCl and contained a small RNA of approximately 5.5 X 10(5) molecular weight. This report demonstrates that delta antigen is associated with a unique subpopulation of hepatitis B surface antigen particles and small RNA in human serum.

A solid-phase enzyme immunoassay (EIA) for detection of HBeAg and anti-HBe

A sensitive, reproducible and easily performed enzyme immunoassay (EIA) based on a sandwich technique is described for serological detection of HBeAg and anti-HBe. EIA appears to be 600 times more sensitive than immunodiffusion and counterimmunoelectrophoresis and its performance compares well with available radioimmunoassays.

Radioimmunoassay for the detection of HBeAg and anti-HBe

We describe a solid-phase radioimmunoassay, based on the "sandwich" principle, using anti-HBe1/anti-HBe2 containing IgG precoated to polystirene beads as the solid-phase, and 125I-anti-HBE as labelled antibody for the detection of HBeAg and a two steps competitive procedure for the detection of anti-HBe. Comparison of titre obtained by ID and RIA or reference sera containing HBeAg and anti-HBe revealed that RIA is about 200 fold more sensitive than ID in detecting both HBeAg and anti-HBe. Moreover an increase in the detection rate of HBeAg from 5.9% (ID) to 15% (RIA) and of anti-HBe from 47.8% (ID) to 74.2% (RIA) and consequently a reduction of the frequency of negative samples for both HBeAg and anti-HBe from 46.3% (ID) to 10.8% (RIA) was determined by testing sera from HBsAg asymptomatic carriers. With regard to specificity, the frequency of presumptive HBeAg positive samples not confirmed was of 1 out of 29 (3.4%). Technical improvements of sensitivity and specificity of the described RIA are under development.

Normal lymphocyte interferon production in adult HBsAg-positive chronic active liver disease

To challenge the hypothesis that interferon (IF) production in chronic hepatitis-B virus liver disease is defective, lymphocytes from 14 patients with chronic active liver disease (CALD); from nine patients with chronic inactive liver disease (CILD), and from six healthy chronic carriers (HCC) were stimulated by Newcastle Disease virus. The patients with CILD showed a weak IF response by comparison with the controls (P less than 0.0005), whereas IF production by CALD patients and the HCC did not statistically differ from IF production in the healthy hepatitis-B surface antigen negative subjects who served as controls. These results indicate that IF treatment of CALD does not rely on a completely proved background.

Incidence and significance of different types of connective tissue antibodies in adult and pediatric gastroenterological disorders

The incidence of connective tissue antibodies was assessed in 3,000 adults and in 388 pediatric patients with gastroenterological disorders. Following a previous classification, connective tissue antibodies were distinguished in 5 different types, R1 and R2 reacting with reticulin components, KC with Kupffer cells, AC and Rs with intra- and extracellular mesenchymal antigens. R1 predominated in children and was observed only in patients with malabsorption; the great majority of them had celiac disease and an abnormal small bowel mucosa. Ac was rarely seen in children and occurred in several unrelated gastrointestinal diseases of the adult; its incidence, however, was significantly higher in disorders with idiopathic and secondary malabsorption. R2, KC and Rs were seen only occasionally in unrelated gastroenterological disorders without malabsorption. R1, therefore, seems to be strongly suggestive of a malabsorption syndrome with abnormal small bowel mucosa and AC is a nonspecific reaction occuring predominantly in primary and secondary malabsorption; the other connective tissue antibodies have no clinical significance in gastroenterological disorders.

Immunofluorescence detection of new antigen-antibody system (delta/anti-delta) associated to hepatitis B virus in liver and in serum of HBsAg carriers

A new antigen-antibody system associated with the hepatitis B virus and immunologically distinct from the HB surface, core, and e systems is reported. The new antigen, termed delta, was detected by direct immunofluorescence only in the liver cell nuclei of patients with HBsAg positive chronic liver disease. At present, the intrahepatic expression of HBcAg and delta antigen appears to be mutually exclusive. No ultrastructural aspect corresponding to the delta antigen could be identified under the electron microscope. delta antibody was found in the serum of chronic HBsAg carriers, with a higher prevalence in patients with liver damage. The nuclear fluorescence patterns of HBcAg and delta antigen were similar; it is only possible to discriminate between the two antigens by using the respective specific antisera.

A counterimmunoelectrophoretic technique for the detection of HBeAg/anti-HBeAg (e antigen/antibody) in human sera

A counterimmunoelectrophoretic technique is presented for the serological detection of the e system. Counterimmunoelectrophoresis was found reproducible and easy to perform; it is quicker and more sensitive than immunodiffusion since out of 243 HBSAg positive carriers, it detected HBeAg or anti-HBe in other 42 (17.3%) sera in addition to the 96 positive by immundiffusion.

The immunological diagnosis of HBsAg liver disease by combined screening for the e system in the serum and the HB core and surface antigens in liver biopsy samples

Serological screening for HBeAg and anti-HBe, combined with the immunohistochemical localization of the hepatitis B core and surface antigen in 110 HBsAg carriers, established different immunological profiles indicative of the liver status and prognostic of the future absence or progression of the disease. Intrahepatic HBcAg and serum HBeAg appeared the most sensitive indexes of chronic and progressive liver disease, anti-HBe and large amounts of cytoplasmic HBsAg suggest, instead, the asymptomatic carrier state without liver damage. Only the nuclear localization of HBcAg in immunohistochemical studies was a reliable prognostic indicator of transition to chronicity; absence or presence of serum HBeAg was of no help in predicitng the outcome of acute HBsAg hepatitis.

Complement fixing hepatitis B core antigen immune complexes in the liver of patients with HBs antigen positive chronic disease

One hundred and fifty-two biopsies from serologically HBsAg positive and negative patients with liver disease were studied in immunofluorescence: for the presence of the surface (HBs) and the core (HBc) antigenic determinants foeterminants of the hepatitis B virus, of immunoglobulins and complement (C) deposits, and for the capacity to fix human C. Circumstantial evidence is presented suggesting that HBc immune-complexes are a relevant feature in the establishment and progression of chronic HBSAg liver disease. C fixation by liver cells was shown in all HBC positive patients with chronic hepatitis; an active form was present in every case, except two with a persistent hepatitis, an inverse ratio of HBc to C binding fluorescence being noted between active chronic hepatitis and cirrhotic patients. HBc without C fixation was observed in only three patients in the incubation phase of infectious hepatitis. IgG deposits were often found in HBc containing, C fixing nuclei. No C binding or IgG deposits were observed in acute self-limited type B hepatitis, in serologically positive patients with normal liver or minimal histological lesions, with and without HBs cytoplasmic fluorescence in their biopsy, or in serologically negative individuals.