Cytoplasmic localisation of Australia antigen in the liver

Milestones and perspectives in viral hepatitis B

There have been numerous research milestones since the discovery of the hepatitis B virus (HBV) in the 1960s. These mark major advances in the serology and epidemiology of HBV infection, in identifying the wide clinical spectrum of acute and chronic hepatic diseases as well as the extrahepatic conditions induced by this virus, the molecular biology of the virus including its variants and mutants, its molecular diagnosis and monitoring, the host immune responses to the infecting virus, the pathogenesis and immunopathogenesis of liver disease as well as its natural course and outcome. These landmark discoveries are the firm background for current and future developments in treatment. There are three consecutive and partly overlapping chronological periods to treatment milestones beginning with recombinant standard interferon-alpha (IFN-α) in the 1980s, then oral antivirals from 1998 to the present and in 2005 pegylated IFN-α (PEG-IFN). The renewed interest in PEG-IFN-α treatment is now focused on both HBeAg-positive and HBeAg-negative chronic hepatitis B and it now also aims at HBsAg loss when associated with on-treatment monitoring of serum HBV DNA and HBsAg levels, resulting in the closest thing to a cure of hepatitis B. The impressive progress made in all aspects of hepatitis B research suggests that curative therapy may be developed for all patients and for all phases of HBV infection in the foreseeable future. However for the moment, realistic efforts should be made to make treatment as widely available and affordable as possible and to apply current therapies to significantly reduce HBV morbidity and mortality.

Hepatitis B virus pre-S mutants, endoplasmic reticulum stress and hepatocarcinogenesis

Although hepatitis B virus (HBV) has been documented to cause hepatocellular carcinoma (HCC), the exact role of HBV in the development of HCC remains enigmatic. Several hypotheses have been proposed to explain the potential mechanism, including insertional mutagenesis of HBV genomes and transcriptional activators of HBV gene products such as hepatitis B x protein (HBx) and truncated middle S mutants. In the past few years, we have identified two types of large HBV surface antigens (LHBs) with deletions at the pre-S1 (DeltaS1-LHBs) and pre-S2 (DeltaS2-LHBs) regions in ground glass hepatocytes. The pre-S mutant LHBs are retained in the endoplasmic reticulum (ER) and escape from immune attack. The pre-S mutants, particularly DeltaS2-LHBs, are increasingly prevalent in patients with hepatitis B e antigen (HBeAg)-positive chronic HBV infection, ranging from 6% before the 3rd decade to 35% in the 6th decade. In HCC patients, the two pre-S mutants were detected in 60% of HCC patients, in the serum and in HCC tissues. Pre-S mutant LHBs can initiate ER stress to induce oxidative DNA damage and genomic instability. Furthermore, pre-S mutant LHBs can upregulate cyclooxygenase-2 and cyclin A to induce cell cycle progression and proliferation of hepatocytes. In transgenic mice, the pre-S mutants can induce dysplasia of hepatocytes and development of HCC. In a nested control study, the presence of pre-S mutants carried a high risk of developing HCC in HBV carriers. In summary, the findings we describe in this review suggest a potential role for HBV pre-S mutants in HBV-related hepatocarcinogenesis, providing a model of viral carcinogenesis associated with ER stress.

Significance of hepatitis B core antigen in the liver in patients with chronic hepatitis B and its relation to hepatitis B virus DNA

Liver biopsies from 52 patients with chronic hepatitis B were investigated for the presence and distribution of HBcAg and the results were compared with the status of hepatitis B virus deoxyribonucleic acid (HBV-DNA). The patients consisted of 37 men and 15 women, aged 16-55 years (mean = 34 years). Serum alanine aminotransferase (ALT) was elevated in 50 patients (range: 18-969 U/L; mean = 290 U/L). Serological testing showed HBsAg in all, HBeAg in 45 (87%), and HBV-DNA in 28 (54%). Liver biopsies demonstrated HBcAg in 35 (67%) patients. HBcAg was not only present in 31 of 45 (69%) patients who were seropositive for HBeAg, but also in four of seven (57%) with antibody to HBeAg (anti-HBe). In 28 of 35 (80%) patients with HBcAg in the liver, serum HBV-DNA was detected. However, no serum HBV-DNA was detected in 17 patients who had no detectable HBcAg in the liver. The distribution of HBcAg in the liver was rather cytoplasmic and nuclear than nuclear alone. Among 33 patients with cytoplasmic HBcAg in the liver, 15 (45%) had an evidence of acute exacerbation of hepatitis with marked ALT elevation (range: 168-894 U/L; mean = 385 U/L) and nine patients showed severe chronic active hepatitis and confluent necrosis, histologically. These results indicate that the presence of HBcAg in the liver correlates with the amount of circulating hepatitis B virus as quantified by serum level of HBV-DNA. The predominant cytoplasmic HBcAg in the liver may suggest the possibility of multiple episodes of acute exacerbation and more severe ongoing hepatitis during the clinical course.

Relationship between T-lymphocyte subsets and suppressor cell activity in patients with chronic active hepatitis B

Thirty-nine patients with chronic HBV infection and 38 normal persons were investigated by simultaneous assay of T suppressor cell function and enumeration of T-lymphocyte subsets by monoclonal antibodies. In patients with chronic active hepatitis B (CAH-B), T suppressor cell activity (17.8 +/- 8.8%) was significantly lower than in healthy HBsAg carriers (35.4 +/- 12.3%) and normal control persons (38.3 +/- 16.3%). The proportions of T-lymphocyte subsets in patients with CAH-B were not different from those of healthy HBsAg carriers and control persons. No correlation was observed in between percentage suppression and proportions of T-lymphocyte subsets. These findings suggest that in the absence of a simultaneous assay of function, enumeration of T-lymphocyte subsets by using monoclonal antibodies is an inadequate assessment of immune regulation.

Peroxidase-anti-peroxidase detection of hepatitis B surface and core antigen in liver biopsy specimens from patients with chronic type B hepatitis

Liver biopsy specimens from 58 American patients with chronic type B hepatitis were investigated for the presence and distribution of the hepatitis B core (HBcAg) and surface (HBsAg) antigens by peroxidase-anti-peroxidase techniques. HBsAg was detected in 43 (77%) and HBcAg in 52 (90%) patients. HBcAg was present in 50 of 51 (98%) patients with hepatitis B e antigen (HBeAg) but in only two of seven (29%) of patients with antibody to HBeAg (anti-HBe). There was no correlation between severity of hepatitis or height of aminotransferase activities and the amount of HBsAg or HBcAg in hepatocytes but there was a positive correlation between amount of HBcAg and height of HBV-DNA and DNA polymerase activity in serum. Follow-up liver biopsies, taken 1 to 3 yr later, were available from 39 patients. HBcAg remained detectable in 25 of 26 patients with persistence of HBeAg but disappeared in 12 patients who had lost HBeAg. In nine patients, HBcAg was cytoplasmic as well as nuclear in distribution. Seven of these patients had an intense lobular hepatitis with marked elevations in aminotransferase activities. These findings indicate that the amount of HBcAg in liver correlates with the amount of serum hepatitis B virus as quantified by serum levels of DNA polymerase and HBV-DNA. The amount of nuclear HBcAg does not correlate with the severity of the liver disease, but the presence of cytoplasmic HBcAg usually reflects an active and severe ongoing hepatitis.

Viral hepatitis

Developments over the last four years in our understanding of viral hepatitis are analyzed. The molecular structure of hepatitis A has been established, and vaccines for prevention are under development. The recognition of the replicative and integrated stages of hepatitis B infection has allowed more rational approaches to therapy. Vaccines are of proven value. Delta virus infection has assumed an important role world wide as a cause of serious and fulminant liver disease in hepatitis B carriers. The agents for non-A, non-B virus hepatitis have eluded identification. These are important causes of chronic liver disease particularly in recipients of blood transfusion.

Methods for localization of hepatitis B surface antigen in liver tissue. An evaluation of different staining- and tissue preparation methods

To investigate different staining techniques for demonstration of hepatitis B-surface antigen a series of 250 liver biopsies were stained with direct immunofluorescence (I.F.) on frozen tissue and indirect immunoperoxidase (I.P.), direct I.F., orcein and haema toxylin-eosin (H.E.) on paraffin embedded tissue. Examination of different fixatives and various fixation times of formalin fixed tissue on the demonstration of HBsAg was performed on liver tissue from one case with large amounts of HBsAg in the tissue. Among 70 HBsAg sero-positive cases only 27 were tissue positive. In 51 sero-positive AVH cases, 11 were positive with I.F., 3 with I.P., one with orcein and none with H.E. In the remaining 19 sero-positive cases, representing 9 cases with chronic hepatitis, 6 cases with cirrhosis, 3 cases with non-specific reactive changes and one case without pathological changes, 15 cases were positive with I.F. as well as with I.P., 9 with orcein and 5 with H.E. Membrane related staining reaction was best preserved when using Bouin's and Clarke's fixative. No difference was observed between different fixatives as regards intracytoplasmic staining reaction. Formalin fixation for more than 7 hours duration caused a decrease in the amount of demonstrable HBsAg, which only to a limited extent could be restored by pre-treatment with proteolytic enzyme.

Analysis of liver disease, nuclear HBcAg, viral replication, and hepatitis B virus DNA in liver and serum of HBeAg Vs. anti-HBe positive carriers of hepatitis B virus

Nine HBeAg+ and 24 anti-HBe+ subjects with chronic hepatitis B virus (HBV) infection were studied for HBV DNA in the serum by molecular hybridization, for HBcAg in the liver by immunofluorescence, and for histologic evidence of liver disease. All HBeAg+ patients had underlying chronic liver disease (chronic persistent hepatitis, chronic active hepatitis, or cirrhosis with or without hepatocellular carcinoma), and all were found positive for both HBV DNA in the serum and HBcAg in the nucleus of hepatocytes. Of the 24 anti-HBe+ individuals, 18 had various forms of chronic liver disease. Six HBsAg+/anti-HBe+ patients had normal liver histology except for numerous "ground-glass" hepatocytes with abundant cytoplasmic HBsAg. All six were negative for nuclear HBcAg and serum HBV DNA, but three showed HBV DNA which appeared to be integrated into unique sites in host liver DNA by hybridization analysis. In contrast, 14/18 (78%) of HBsAg+/anti-HBe+ patients with chronic liver disease were positive for nuclear HBcAg, serum HBV DNA, or both of these markers of HBV replication. It is suggested that in long-term HBsAg carriers with serum anti-HBe and normal liver histology, viral replication is suppressed or inactive and HBV potential infectivity is presumably very low or absent. However, when viral replication is present in HBsAg+/anti-HBe+ carriers (as demonstrated by serum HBV DNA and/or nuclear HBcAg), active liver disease is often found. In these individuals, active chronic liver disease appears to be related to continued replication and secretion of HBV and may occur in a much higher proportion of HBsAg+/anti-HBe+ carriers than was previously suspected.

Prognostic significance of piecemeal necrosis in acute viral hepatitis

The predictive value of piecemeal necrosis (PMN) in acute hepatitis was investigated in 62 patients (39 hepatitis B virus infection, 9 hepatitis A virus infection and 14 possible hepatitis NANB virus infection). The 62 initial biopsies were blindly recoded and classified into three groups: 1. Acute hepatitis with signs of possible transition to chronicity (AHTC) (n = 35) (i.e. a picture of acute hepatitis associated with PMN). 2. AHTC-borderline group (BL) (n = 15) (i.e. a picture of acute hepatitis with minimal PMN). 3. Uncomplicated acute hepatitis (AH) (n = 12) (i.e. a picture of acute hepatitis without PMN). Follow-up of the patients revealed an evolution to chronicity in a very high percentage of the AHTC-cases of hepatitis B (95%) and NANB (89%) etiology. Also 67% of the BL-cases of hepatitis B etiology developed chronic liver disease. In hepatitis B the immunohistochemical pattern of HBsAg is of additional help. In hepatitis A, PMN is often present (5/9) but no evolution to chronicity was observed. This study shows that PMN in acute hepatitis appears to be a useful prognostic feature for chronicity in hepatitis B and NANB.

Modern aspects of the morphology of viral hepatitis

The morphologic pathology of human viral hepatitis and its sequelae are reviewed in this article. Emphasis is placed on new information, including the current status of the pathologic diagnosis of hepatitis non-A, non-B. The article includes a discussion of aspects of the virology that are pertinent to an understanding of the significance of viral markers in the liver. A small contribution of the authors is a brief description of the neocholangiole, a duct of Hering-like structure seen following hepatic necrosis from many causes, including the severe forms of viral hepatitis.

Effect of protease pretreatment on immunomorphologic demonstration of hepatitis-B-surface antigen in conventional paraffin-embedded liver biopsy material: quantitative evaluation

The effect of protease pretreatment on the demonstration of hepatitis-B-surface antigen by immunofluorescence (IF) and the unlabeled peroxidase-antiperoxidase technique (PAP) in conventionally processed (formalin-fixed, paraffin-emmbedded) liver biopsy material was quantitatively assessed by microphotometry. Protease digestion significantly enhances the intensity of specific staining by both methods, and, in addition, suppresses non-specific background fluorescence. The sensitivity of the immunomorphologic test is significantly enhanced, and antigen in low amounts, for example hepatitis-B-surface antigen associated with liver cell membrane ('membrane' staining), is easily detected.

HBsAg uptake by macrophages in vitro: an immunofluorescence study

The uptake of HBsAg by in vitro cultured macrophages was studied by immunofluorescence method. Intracytoplasmic fluorescent particles appeared 3 h after the contact with HBsAg-positive serum, while after 24-48 h only a few cells contained these particles, which are probably destroyed within the cytoplasm.

Pathology of primary liver cancer

After a brief survey of the factors that play a role in the etiopathogenesis of human hepatocellular carcinomas, a detailed description is given of the macroscopic and microscopic features of human liver cancers as well as their association with cirrhosis. The ultrastructural features of liver cancers of various degrees of differentiation are described. The mode of spread, metastasis formation of primary liver cancers, and most frequent causes of death of liver cancer patients are reviewed.

Physicochemical heterogeneity of hepatitis B e antigen detected in asymptomatic carriers and carriers in a hemodialysis unit

Physicochemical studies of hepatitis B e antigen (HBeAg) revealed a clear cut difference between e1 and e2 antigen. The e1 antigen was found to have a MW of Ca 150,000 and a pI of 6.4-7.2, whereas both the MW and pI of the e2 antigen were heterogeneous depending upon the source of serum. Sera obtained from asymptomatic carriers were characterized by low titers of HBs antigen, HBc antigen and DNA polymerase and contained e2 antigen of larger molecular weight (200,000-300,000) with a narrow distribution range and a pI of 4.8 to 5.2 (type 1). On the other hand, the sera from patients in a hemodialysis unit who were HBs antigen carriers and had high titers of HBs antigen, HBc antigen and DNA polymerase contained e2 antigen of heterogeneous distribution in MW (from 300,000 to 70,000) and pI (type 2 and 3). The e2 antigen obtained from the higher MW type 3 serum had lower isoelectric points (pI 4.5 to 5.2) as was the case with e2 antigen obtained from asymptomatic carriers whereas relatively wide range of isoelectric points (pI 5.1 to 8.2) was found with the lower molecular weight e2 antigen.

HBsAg-negative chronic active hepatitis related to hepatitis B virus

Numerous cases of chronic hepatitis have been shown to be closely associated with persistent infection with hepatitis B virus (HBV). A group of 100 patients suffering from chronic active hepatitis (CAH) was investigated for HBV serologic markers. Of these, 35 patients were HbsAg-positive; in 26 HBsAg-negative subjects, anti-HBc were detected using counterimmune electrophoresis and complement-fixation tests. These data suggest that chronic liver disease in patients who were only anti-HBc-positive might be related to persistent infection with hepatitis B virus. Epidemiological clinical and histopathological data were different when we compared CAH patients who were HBsAg-negative, but anti-HBc-positive, with HBsAg-positive CAH patients. A sequence is proposed leading from HBsAg-positive to HBsAg-negative CAH, cirrhosis, and hepatoma in temperate areas, according to a model similar to the one described in intertropical Africa.

Immunohistochemical patterns of hepatitis B surface antigen (HBsAg) in patients with hepatitis, renal homografts recipients and normal carriers

A series of 180, Bouin-fixed and paraffin embedded liver biopsies obtained from 147 patients was investigated for the presence of hepatitis B surface antigen (HBs) by histochemical and indirect immunofluorescence techniques. A comparison between orcein staining and Masson's trichrome preparations for ground glass hepatocytes, showed that immunofluorescence was both the more reliable and the more specific method for detection of HBsAg in liver tissue. The ability to perform this technique on paraffin sections facilitates systematic studies and allows retrospective work-up. IF-HBs positive hepatocytes were found in approximately two thirds of all HBs-positive patients in their serum, but never seen in HBs-negative patients. HBs-positive cells were observed in healthy chronic carriers and in all forms of chronic hepatitis, but never in acute HBs-positive hepatitis. In patients treated with chronic hemodialysis and in renal homograft recipients, the incidence of positive cells was higher than in the chronic hepatitis groups; this could be correlated with the duration of antigenemia at the time of biopsy.

A trichrome stain for the intrahepatic localization of the hepatitis B surface antigen (HBsAg)

A modified trichrome stain is described for the intrahepatic localization of the hepatitis B surface antigen; HBsAg containing cells exhibit specific green metachromasia contrasting with the granular brown colour of non infected hepatocytes and with the deep eosinophilic colour of ground glass cells of HBsAg-negative alcoholic or drug hepatitis. The technique is simple and reliable for routine screening of HBsAg positive material; its sensitivity is greater than H & E, similar orcein and inferior to immunohistochemistry as performed on frozen sections. Histological diagnosis can be made on the same slide, since several other morphological details are provided in the trichrome stained preparations. With this technique 387 biopsies from HBsAg seronegative individuals were negative; full cytoplasms metachromasia was mostly seen in asymptomatic HBsAg carriers, focal or partial staining in patients with histological evidence of liver cell necrosis. The presence and the staining pattern of HBsAg were of no help in predicting transition to chronicity or a transition from chronic persistent to chronic active hepatitis.

[Methodical problems for evidence of the hepatitis-B-surface and hepatitis-B-core antigens in tissue (author's transl)]

Liver biopsy material of 22 in the serum HBsAg positive patients was tested with the fluorescent antibody technique for the localization of HBcAg and HBsAg in the liver tissue. Comparative studies were done with the following tissue preparation techniques: Cryostat technique, freeze drying, freeze substitution, cold ethanol paraffin embedding technique (SAINTE MARIE) and isolated liver cells. The investigations revealed the following results: 1. No HB-components could be detected with the cold ethanol paraffin embedding technique and freeze substitution. 2. Using the cryostat technique HBsAg could be demonstrated in 16/22 (cytoplasmatic localization) and HBcAg in 8/22 (nuclear localization). 3. With freeze drying HBsAg and HBcAg could be found in the same cases. The excellent tissue preparation allowed a correct localization of the HB-components to the cell structure. 4. In comparison to cryostat sections in isolated liver cells HBcAg could be demonstrated in 11/16 and HBcAg in 8/8 cases.

Serial liver biopsy observations in hepatitis B antigen carriers by light and electron microscopy

Liver morphology and function were restudied after an interval of 1 1/2-2 years in 21 Chinese men with hepatitis B antigen (HBsAg). Antigenemia and mild liver histopathology disappeared in one individual who developed antibody to HBsAg(Anti-HBsAg). 20 subjects who were chronic carriers of HBsAg had mild histological abnormalities which were usually persistent and were more commonly lobular than portal. Particularly striking were focal necrosis, eosinophilic bodies, ground-glass cytoplasmic change, and, by electron microscopy, microtubular structures within cytoplasmic membranous cysternae. Interval development of chronic aggressive hepatitis was observed in only one subject. This study suggests that the great majority of HBsAg carriers have a good prognosis at least over a 1 1/2-2-year period, and that liver biopsy is most indicated in those with persistent liver function abnormalities.

Demonstration of hepatitis B surface antigen by orcein staining in paraffin sections of cirrhotic liver

Blood and liver from 44 and 30 patients, died in cirrhosis and other diseases, respectively were tested for the presence of HBSAg. Blood samples obtained at autopsy and in seven cirrhosis cases also before death were tested for HBSAg by counter-electrophoresis. Detection of HBSAg in hepatocytes was carried out in paraffin sections by the modified orcein staining technique of Shikata et al. Ten of 14 HBSAg seropositive and 2 of 30 HBSAg seronegative cirrhotic patients had orcein positive hepatocytes, which were not found in any liver specimen from the 30 non-cirrhotic seronegative patients. The orcein positive substance localized in the cytoplasm of hepatocytes, less often it was also seen in a few Kupffer cells. The hepatocellular carcinoma cells present in part of the livers studied did not contain any orcein positive substance. Histological changes in the cirrhotic livers showed morphological indication of the presence of HBSAg, except on staining with orcein. The modified orcein staining technique is a simple, handy procedure for use in any routine pathological laboratory and has the additional advantage of detecting HBSAg also in stored paraffin blocks.

Hepatitis B surface antigen (HBsAg) in the liver of patients with hepatitis; a comparison with serological detection

Chronic hepatitis was diagnosed on liver biopsy of 76 patients; 52 (68%)had HBsAg. Of the 52 patients with HBsAg, 23% had HBsAg shown by immunofluorescence on the liver, while it could not be detected with radioimmunoassay on the serum; 77% had HBsAg detectable in liver and in serum, and none had HBsAg in serum only. HBsAg was detected more frequently in chronic aggressive hepatitis and active cirrhosis than in chronic persistent hepatitis and cirrhosis with little activity. No correlation was found in the different forms of chronic hepatitis between the HBsAg status on the one hand, and levels of transaminases, gammaglobulins, and auto-antibodies on the other. Acute hepatitis was diagnosed on liver biopsy of 24 patients; 50% had HBsAg. Liver tissue positivity was very low in the fully developed stage compared to serum positivity. In 146 patients with other liver ailments, both liver and serum were negative for HBsAg.

The localisation of hepatitis B antigen and immunoglobulin G in liver tissue: an immunofluorescence, light and electron microscopic study

Liver tissue specimens for 43 HBAg seropositive patients and 22 HBAg seronegative individuals were investigated for the presence of HBAg with the immunofluorescence technique. Histological diagnoses were established with light microscopy on routinely stained frozen liver sections. The liver specimens of 42 out of the 43 HBAg-positive patients showed positive fluorescence. Three distinct fluorescence patterns could be observed: diffuse, focal and solitary. The diffuse pattern appeared to occur particularly in chronic aggressive or persistent hepatitis, the focal pattern was seen only in the group of patients without obvious alterations and the solitary pattern especially in acute hepatic necrosis.

Intrahepatic localization of the surface (HBsAg) and core (HBcAg) antigenic determinants associated with hepatitis B virus in biopsy samples from patients with liver disease

109 biopsy samples from 35 HBAg serologically positive and 74 negative patients were examined by IFL for the presence of the surface and core antigenic determinants associated with the Dane particle. In no serologically negative case was specific IFL detected. Different patterns were observed in serologically positive patients: negative in acute hepatitis, strongly positive cytoplasmic HBs fluorescence in chronic HBAg carriers with normal liver, and discrete HBsAg parenchymal and mesenchymal staining and variable HBcAg staining in chronic liver disease, with HBsAg appearing more frequently in active and HBcAg in active disease. These results are compared with recent reports in this field and the clinical significance of the intrahepatic localization of HBAg is discussed.

Immunofluorescent detection of alpha1-antitrypsin in paraffin embedded liver tissue

Alpha1-antitrypsin was detected by indirect immunofluorescence in frozen sections of liver biopsies from patients with clinically and biochemically proven alpha1-antitrypsin deficiency. The antigen could also be demonstrated in those liver specimens of the same patients which were fixed in Bouin's fluid and embedded in paraffin. The cellular localization and the brightness of the fluorescence were the same in both frozen and paraffin sections. Four additional biopsies from three other patients were selected on the basis of PAS-positive diastase-resistant inclusions reported in the hepatocytes. All these biopsies showed bright fluorescence in the cytoplasm of the liver cells although one of the biopsies was stored for as long as eight years. Specific fluorescence was constantly found in the periportal hepatocytes with varying degrees of positivity. No fluorescence was observed in the six control biopsies from patients with various other liver diseases. These findings prove that paraffin embedded specimens are suitable for immunofluorescence detection of alpha1-antitrypsin and that a retrospective study on old paraffin blocks is possible.

HBs-Ag, HBc-Ag and virus-like particles in liver tissue

Hepatitis B surface antigen (HBs-Ag) and hepatitis B core antigen (HBc-Ag) in hepatic tissue of 3 cases with various liver diseases were investigated by immunofluorescent method. Virus-like particles were demonstrated by electron microscopy in the nuclei of these 3 cases. The localization of HBs-Ag was restricted in cytoplasma or on the surface of hepatocyte, while HBc-Ag was almost in the hepatocytic nuclei. However, there was unexplainable discrepancy between the distribution of HBs-Ag and that of HBc-Ag, as more the former in number and less that latter, of hepatocytes. The size of virus-like particles in nuclei was 22-27 nm in diameter. Most of them were hollow, but some of them were wholly electron dense. Their distribution was various from case to case. Discussion was made on the correlation between the presence of Hepatitis B virus and HBs-Ag or HBc-Ag.

Immunoperoxidase localisation of hepatitis B antigen (HB) in formalin-paraffin processed liver tissue

The unlabelled antibody-enzyme (PAP) method was used to demonstrate HB in sections of routine formalin fixed paraffin embedded liver biopsies.

The ground glass hepatocyte as a diagnostic hint

One hundred seven women 18–65 years old were studied who were referred for suspected central nervous system disease not related to the pituitary gland or hypothalamus. High-resolution, direct, coronal, contrast-enhanced computed tomography (CT) was used to examine the size, shape, and density of the normal pituitary gland. There were three major conclusions: (1) the height of the normal gland can be as much as 9 mm; (2) the superior margin of the gland may bulge in normal patients; and (3) both large size and convex contour appear to be associated with younger age. It was also found that serum prolactin levels do not appear to correlate with the CT appearances. Both low- and high-density areas were seen within the gland, and may be due to either tumors, cysts, infarcts, or metastases. Noise artifacts inherent in high-detail, thin-section, soft-tissue scanning may be a limiting factor in defining reproducible patterns in different parts of the normal pituitary gland.

Immunofluorescent detection of hepatitis B antigen in paraffin-embedded liver tissue

Hepatitis B antigen (HBAg) has been demonstrated by the indirect immunofluorescent technique and by orcein staining in 20 liver biopsies fixed in Bouin's fixative and embedded in paraffin. The results were compared with those obtained previously by immunogluorescence on frozen sections of the same biopsies. Ten biopsies which were positive in frozen sections were also positive by immunofluorescence in parafin sections, whereas only six were positive by orcein staining. In orcein-stained sections, the cellular localization of HBAg was precisely in the same places as in the slides examined by immunogluorescence. The intessity of the fluorescence in paraffin sections was almost the same as in frozen sections. The localization of the antigen was histologically more precise in paraffin sections. Besides various advantages, indlucing aboidance of freezing aquipment and procedures, paraffin sections are more easy to handle and biopsies from distant hospitals can be processed. The advantages of the immunofluorescent test in comparison to orcein staining are its immunological specificity and higher sensitivity.

The role of immunological mechanisms in acute and chronic hepatitis

Studies of asymptomatic carriers of hepatitis B antigen (HB Ag) have suggested that the hepatitis B virus may not be directly damaging to liver cells and it is possible that the hepatocellular necrosis which accompanies acute hepatitis may be induced by immunological reactions directed at viral antigenic determinants on the surface of infected cells.

Immunological reactions may also be implicated in the pathogenesis of active chronic hepatitis. Although antibodies which are commonly present in the serum are probably not of primary importance in the immunopathology, recent studies have demonstrated liver-specific immune responses, both humoral and cellular, which may be more directly related to the pathogenesis.