Relationship between the intrahepatic expression of 'e' and 'c' epitopes of the nucleocapsid protein of hepatitis B virus and viraemia.
The relationship between hepatitis B viraemia and intrahepatic HBV nucleocapsid proteins (HBcAg and HBeAg) was studied in 18 patients with chronic hepatitis B. Monoclonal antibodies (MoABs) were obtained in BALB/c mice primed with recombinant HBV nucleocapsid proteins. Four MoABs reacting with recombinant proteins gave positive results in competitive assays. Two reacted as anti-HBc and two as anti-HBe. One of them showed a strong affinity for the cytoplasmic, membrane-bound antigen (P23e) of infected hepatocytes while the latter showed a higher specificity for serum HBeAg than for the intrahepatic antigen. Anti-HBc MoABs had a staining capacity for liver cell nuclei comparable with that of polyclonal antibodies. Overall the anti-HBc MoABs stained the liver cell nuclei in 86% of cases, while anti-HBe MoABs stained in 58% of cases. The hepatocyte cytoplasm was stained by anti-HBc MoABs and anti-HBe MoABs in 64% and 72% of cases respectively. Not one of 12 control liver biopsies was stained. Viraemia (HBV-DNA) was measured by dot blot hybridization and was correlated with the number of hepatocytes containing the nucleocapsid antigen. The highest levels of HBV-DNA (greater than 10(8) genomes/ml) were detected in patients with prevalent nuclear staining while the lowest ones were observed in those with prevalent cytoplasmic expression of this antigen. The application of anti-HBV-nucleocapsid MoABs in diagnostics requires careful scrutiny since some are specific for the circulating antigen while others show a higher affinity for the intrahepatic antigen.
Ballaré
M
M
Dipartimento di Biomedicina, Universitá di Torino, Italy.
Lavarini
C
C
Brunetto
M R
MR
Petruzzelli
E
E
Dovis
M
M
Molino
G
G
Bonino
F
F
D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D002467:Cell Nucleus / Q000276:immunology; D004279:DNA, Viral / Q000032:analysis; D000939:Epitopes / Q000032:analysis*; D006509:Hepatitis B / Q000276:immunology*; D006510:Hepatitis B Antibodies / Q000032:analysis; D006512:Hepatitis B Core Antigens / Q000032:analysis*; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006513:Hepatitis B e Antigens / Q000032:analysis*; D006801:Humans; D008099:Liver / Q000276:immunology; D014766:Viremia / Q000276:immunology*
D000911:Antibodies, Monoclonal; D004279:DNA, Viral; D000939:Epitopes; D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens