title: Higher cut-off index value of immunoglobulin M antibody to hepatitis B core antigen in Taiwanese patients with hepatitis B.
abstract: BACKGROUND
  The cut-off index value of immunoglobulin M (IgM) antibody to hepatitis B core antigen (anti-HBc; AxSYM CORE-M, Abbott) for diagnosing acute hepatitis B is 1.2. A high false-positive rate of IgM anti-HBc was observed in acute flare-ups of chronic hepatitis B in Taiwanese patients. Thus the purpose of the present paper was to study the optimal index value of IgM anti-HBc in Taiwanese subjects.
  
  
  METHODS
  The peak index values of 42 IgM anti-HBc-positive patients were collected. There were 20 acute hepatitis B patients and 22 patients with chronic hepatitis B with acute flare. The biochemical, virological, and serological data were obtained.
  
  
  RESULTS
  There were significant differences in mean age (36 vs 47 years, P = 0.01), serum alanine aminotransferase level (2042 U/L vs 1193 U/L, P = 0.02) and peak index value of IgM anti-HBc (2.9 vs 1.5, P < 0.01) between patients with acute hepatitis B and those with acute flare of chronic hepatitis B. Eleven (50%) of 22 patients with chronic hepatitis B with acute flare had index value of >1.2. The optimal cut-off index value to differentiate acute hepatitis B from chronic hepatitis B with acute flare was 2.4-2.5, with a sensitivity of 90% and specificity of 90%.
  
  
  CONCLUSIONS
  The cut-off index value of IgM anti-HBc to differentiate acute hepatitis B from chronic hepatitis B with acute flare among Taiwanese patients should be set at 2.4-2.5 instead of 0.8-1.2.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, San-Chung Branch, Taipei County Hospital, Taipei, Taiwan.
authors.forename: Yi-Wen
authors.initials: YW
authors.lastname: Huang
authors.forename: Chih-Lin
authors.initials: CL
authors.lastname: Lin
authors.forename: Pei-Jer
authors.initials: PJ
authors.lastname: Chen
authors.forename: Ming-Yang
authors.initials: MY
authors.lastname: Lai
authors.forename: Jia-Horng
authors.initials: JH
authors.lastname: Kao
authors.forename: Ding-Shinn
authors.initials: DS
authors.lastname: Chen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006509:Hepatitis B / Q000097:blood* / Q000276:immunology; D006512:Hepatitis B Core Antigens / Q000276:immunology*; D006801:Humans; D007075:Immunoglobulin M / Q000096:biosynthesis / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012189:Retrospective Studies; D013624:Taiwan
chemical_list: D006512:Hepatitis B Core Antigens; D007075:Immunoglobulin M