[Evaluation of micro particle enzyme immunoassay technique (MEIA)-IMx for the detection of IgM class antibody to hepatitis B core antigen].

The new Micro Particle Enzyme Immunoassay technique (MEIA, IMx HBc-M, Abbott) had been recently introduced for the detection of IgM class antibody to hepatitis B core antigen (IgM anti-HBc). To evaluate the feasibility of using the IMx HBc-M, we carried out comparison tests between this method. RIA and EIA using sera from acute hepatitis B and type B chronic liver disease. Results obtained were as follows: In the test of 98 sera from acute hepatitis B patients, 92 (93.9%) were positive for IgM anti-HBc by IMx HBc-M, 96 (98.0%) by RIA and 82 (83.7%) by EIA. The four sera which were positive by RIA, but not by IMx were ones obtained from 5 to 12 month after onset. In the test of 267 sera from B type chronic liver disease patients, 93 (34.8%) were positive by IMx HBc-M, 109 (40.8%) by RIA and 23 (8.6%) by EIA. There was a difference in the positive rate between IMx HBc-M and RIA among type B chronic liver disease: the positive rate was higher in RIA than in IMx HBc-M among type B active chronic hepatitis, but only a little higher in IMx HBc-M than RIA among hepatocellular carcinoma. IgM anti-HBc titer was significantly higher in acute hepatitis type B than in chronic liver disease, and was so even in the phase of HBsAg negative in acute hepatitis. IgM anti-HBc was assayed within 45 minutes by IMx, and the procedure was simple because of the auto analyser used in this method.(ABSTRACT TRUNCATED AT 250 WORDS)