[Evaluation of micro particle enzyme immunoassay (MEIA) for the demonstration of antibody to hepatitis B surface antigen].

A fully automated microparticle enzyme immunoassay (IMx AUSAB, Abbott) has been recently introduced for the detection of the presence of antibody to hepatitis B surface antigen (anti-HBs). The present trial was carried out to determine the feasibility of using the IMx AUSAB with sera and plasma, and for comparison with RIA (AUSAB, Abbott) and EIA (AUSAB EIA, Abbott). According to the kinds of vaccines used and locations of residents, the subjects were divided into six groups. Results obtained were as follows; In the test of 642 sera from 446 vaccines and 196 other inhabitants of Okinawa and Miyazaki prefectures, 388 (87.0%) were found positive for anti-HBs using IMx, 392 (87.9%) with RIA and 359 (80.5%) with EIA. Among those vaccinated with recombinant vaccines, 96.6% were found positive with IMx, 96.2% with RIA and 89.4% with EIA. Among subject vaccinated with plasma derived vaccines, 72.9% were found positive with IMx, 75.7% with RIA, and 68.5% EIA. Quantitative agreement between IMx and RIA among the six groups gave linear correlation coefficients ranging from 0.459 to 0.821. In the group vaccinated with the recombinant vaccine by K company (r = 0.459), anti-HBs was confirmed in many sera by IMx compared to that confirmed by RIA and EIA. In addition, anti-HBs was assayed within one hour by IMx and the procedure was simplified by autoanalyser equipped for this method. The results indicate that the sensitivity of IMx is equal to that of RIA and more than that of EIA, and that quantitative linear correlations were obtained between IMx and RIA, and IMx and EIA.