title: Clinical significance of a highly sensitive enzyme immunoassay of hepatitis B surface antigen using a novel electron spin resonance technique.
abstract: We developed a highly sensitive enzyme immunoassay (EIA), the p-AP/HHTIO method, that detects serum hepatitis B surface antigen (HBsAg) by measuring stabilized nitroxide radicals using a novel electron spin resonance technique [Matsuo et al. (1998) Free Radic Biol Med 25:929-935]. To demonstrate the clinical significance of this method and to reveal occult hepatitis B virus (HBV) infection in patients, we used the method to analyze serum samples of 30 patients with acute or fulminant hepatitis who were negative for HBsAg by standard EIA, and those of seven chronic HBV carriers who became negative for HBsAg during a follow-up period by standard EIA. We also examined serum HBV DNA by amplification of the HBV S gene, using the polymerase chain reaction (PCR) technique. The p-AP/HHTIO method showed that 9 of 20 (45%) patients with acute hepatitis and 2 of 10 (20%) with fulminant hepatitis were positive for HBsAg; PCR detected HBV DNA in these HBsAg-positive patients. Antibody against hepatitis B core antigen was detected in one patient with fulminant hepatitis. The p-AP/HHTIO method demonstrated prolonged seropositivity of HBsAg even after standard EIA showed a loss of HBsAg in all seven HBV carriers. Our p-AP/HHTIO method is useful for screening and diagnosing HBV infection in patients with liver diseases who are negative for conventional HBV-related serological markers.
authors.affiliation: Second Department of Internal Medicine, Yamagata University School of Medicine, Yamagata, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Aoki
authors.forename: Takafumi
authors.initials: T
authors.lastname: Saito
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Taku
authors.initials: T
authors.lastname: Matsuo
authors.forename: Koji
authors.initials: K
authors.lastname: Saito
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Togashi
authors.forename: Sumio
authors.initials: S
authors.lastname: Kawata
authors.forename: Kazuyoshi
authors.initials: K
authors.lastname: Ishikawa
authors.forename: Masaaki
authors.initials: M
authors.lastname: Aoyama
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kamada
authors.forename: Haruhide
authors.initials: H
authors.lastname: Shinzawa
mesh_terms: D000082:Acetaminophen / Q000378:metabolism*; D000328:Adult; D000368:Aged; D003497:Cyclic N-Oxides / Q000378:metabolism*; D004279:DNA, Viral / Q000032:analysis; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005260:Female; D006509:Hepatitis B / Q000175:diagnosis* / Q000821:virology; D006510:Hepatitis B Antibodies / Q000097:blood; D006514:Hepatitis B Surface Antigens / Q000032:analysis / Q000097:blood*; D006515:Hepatitis B virus / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D007093:Imidazoles / Q000378:metabolism*; D007124:Immunoenzyme Techniques / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: C117294:4-hydrazonomethyl-1-hydroxy-2,2,5,5-tetramethyl-3-imidazoline-3-oxide; D003497:Cyclic N-Oxides; D004279:DNA, Viral; D006510:Hepatitis B Antibodies; D006514:Hepatitis B Surface Antigens; D007093:Imidazoles; D000082:Acetaminophen