Sources/Clones
Accurate/Axcel (polyclonal), American Research Products (1734-17), Biodesign (1841), Biogenesis (polyclonal), Biogenex (ESP512, polyclonal), Boehringer Mannheim (BW35A/312), Dako (polyclonal, B586), Fitzgerald (M29091, M22131), Immunon (polyclonal), Novocastra (polyclonal) and Zymed (polyclonal).
Fixation/Preparation
These antibodies are applicable to formalin-fixed, paraffin embedded tissue. No antigen unmasking is required. However, caution is advised when using the ABC immunodetection as hepatocytes contain biotin that may crossreact with the ABC system.
Background
The complete HB virus (Dane particle) is a 42 nm double-stranded DNA virus (Hepadna virus), composed of a 27 nm core particle and envelope, 7 nm in thickness, and immunolocalized within the endoplasmic reticulum of liver cells. The HB core protein of 183 amino acids is encoded by the gene C. It is self-assembling and has binding sites for HBV-RNA which is encapsulated together with viral polymerase. Immunolocalization of HBcAg is cytoplasmic, cytoplasmic membranous and nuclear (Kakumu et al, 1989). Antibodies are raised against HBcAg obtained from recombinant core DNA of HB virus, purified from lysates ofE.coli clones. HBcAg is expressed predominantly in the nuclei of liver cells, although variable immunoreaction may also be seen in the perinuclear cytoplasm (Burns, 1975; Chu & Liaw, 1990).
Applications
Antibody to HBcAg detects the replicative form of the virus found in the nucleus of HB-infected cells. Perinuclear cytoplasmic immunolocalization is sometimes observed. In very actively replicating infections, cells with cytoplasmic reactivity may outnumber those with nuclear labeling. The presence of HBcAg on immunohistochemistry is usually correlated with complete viral synthesis as proved by positivity for viral DNA in both liver and blood, as well as circulating Dane particles in blood (Ballare et al, 1989). Demonstration of HBc in liver cells therefore reflects failure to eliminate cells with active viral replication. This is often associated with signs of active disease (piecemeal necrosis or chronic lobular hepatitis) with a membranous pattern of HBsAg (Bianchi & Dudat, 1994). HBcAg is seen with the greatest frequency in immunosuppressed patients with chronic hepatitis (Tapp & Jones, 1977). Excess accumulation of core particles can be recognized in an H&E stain in rare cases as `sanded' nuclei (Bianchi & Gudat, 1976).
Comments
It is assumed that viral DNA active in HBcAg production is episomal and not integrated into the host genome.
References
•Ballare M, Lavarini C, Brunetto MR et al 1989. Relationship between the intrahepatic expression of e and c epitopes of the nucleocapsid protein of hepatitis B virus and viraemia. Clinical Experimental Immunology 75: 64-69.
•Bianchi L, Gudat F 1976. Sanded nuclei in hepatitis B. Laboratory Investigation 35: 1-5.
•Bianchi L, Gudat F 1994. Chronic hepatitis. In: MacSween RNM, Anthony PP, Scheuer PJ, Burt AD, Portmann BHC (eds). Pathology of the liver. Edinburgh: Churchill Livingstone, pp 363-373. Portmann BHC (eds). Pathology of the liver. Edinburgh: Churchill Livingstone, pp 363-373.
•Burns J 1975. Immunoperoxidase localization of hepatitis B antigen (HB) in formalin-paraffin processed liver tissue. Histochemistry 44: 133-135.
•Chu CM, Liaw YF 1990. Intrahepatic expression of HBcAg in chronic HBV hepatitis: lessons from molecular biology. Hepatology 12: 1443-1445.
•Kakumu S, Arao M, Yoshioka K, Tsutsumi Y, Inoue M 1989. Distribution of HBcAg in hepatitis B detected by immunoperoxidase staining with three different preparations of anti-HBc antibodies. Journal of Clinical Pathology 42: 284-288.
•Tapp E, Jones DM 1977. HBsAg and HBcAg in the livers of asymptomatic hepatitis B antigen carriers. Journal of Clinical Pathology 30: 671-677.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Accurate/Axcel (polyclonal), American Research Products (1734-17), Biodesign (1841), Biogenesis (polyclonal), Biogenex (ESP512, polyclonal), Boehringer Mannheim (BW35A/312), Dako (polyclonal, B586), Fitzgerald (M29091, M22131), Immunon (polyclonal), Novocastra (polyclonal) and Zymed (polyclonal).
Fixation/Preparation
These antibodies are applicable to formalin-fixed, paraffin embedded tissue. No antigen unmasking is required. However, caution is advised when using the ABC immunodetection as hepatocytes contain biotin that may crossreact with the ABC system.
Background
The complete HB virus (Dane particle) is a 42 nm double-stranded DNA virus (Hepadna virus), composed of a 27 nm core particle and envelope, 7 nm in thickness, and immunolocalized within the endoplasmic reticulum of liver cells. The HB core protein of 183 amino acids is encoded by the gene C. It is self-assembling and has binding sites for HBV-RNA which is encapsulated together with viral polymerase. Immunolocalization of HBcAg is cytoplasmic, cytoplasmic membranous and nuclear (Kakumu et al, 1989). Antibodies are raised against HBcAg obtained from recombinant core DNA of HB virus, purified from lysates ofE.coli clones. HBcAg is expressed predominantly in the nuclei of liver cells, although variable immunoreaction may also be seen in the perinuclear cytoplasm (Burns, 1975; Chu & Liaw, 1990).
Applications
Antibody to HBcAg detects the replicative form of the virus found in the nucleus of HB-infected cells. Perinuclear cytoplasmic immunolocalization is sometimes observed. In very actively replicating infections, cells with cytoplasmic reactivity may outnumber those with nuclear labeling. The presence of HBcAg on immunohistochemistry is usually correlated with complete viral synthesis as proved by positivity for viral DNA in both liver and blood, as well as circulating Dane particles in blood (Ballare et al, 1989). Demonstration of HBc in liver cells therefore reflects failure to eliminate cells with active viral replication. This is often associated with signs of active disease (piecemeal necrosis or chronic lobular hepatitis) with a membranous pattern of HBsAg (Bianchi & Dudat, 1994). HBcAg is seen with the greatest frequency in immunosuppressed patients with chronic hepatitis (Tapp & Jones, 1977). Excess accumulation of core particles can be recognized in an H&E stain in rare cases as `sanded' nuclei (Bianchi & Gudat, 1976).
Comments
It is assumed that viral DNA active in HBcAg production is episomal and not integrated into the host genome.
References
•Ballare M, Lavarini C, Brunetto MR et al 1989. Relationship between the intrahepatic expression of e and c epitopes of the nucleocapsid protein of hepatitis B virus and viraemia. Clinical Experimental Immunology 75: 64-69.
•Bianchi L, Gudat F 1976. Sanded nuclei in hepatitis B. Laboratory Investigation 35: 1-5.
•Bianchi L, Gudat F 1994. Chronic hepatitis. In: MacSween RNM, Anthony PP, Scheuer PJ, Burt AD, Portmann BHC (eds). Pathology of the liver. Edinburgh: Churchill Livingstone, pp 363-373. Portmann BHC (eds). Pathology of the liver. Edinburgh: Churchill Livingstone, pp 363-373.
•Burns J 1975. Immunoperoxidase localization of hepatitis B antigen (HB) in formalin-paraffin processed liver tissue. Histochemistry 44: 133-135.
•Chu CM, Liaw YF 1990. Intrahepatic expression of HBcAg in chronic HBV hepatitis: lessons from molecular biology. Hepatology 12: 1443-1445.
•Kakumu S, Arao M, Yoshioka K, Tsutsumi Y, Inoue M 1989. Distribution of HBcAg in hepatitis B detected by immunoperoxidase staining with three different preparations of anti-HBc antibodies. Journal of Clinical Pathology 42: 284-288.
•Tapp E, Jones DM 1977. HBsAg and HBcAg in the livers of asymptomatic hepatitis B antigen carriers. Journal of Clinical Pathology 30: 671-677.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
