Abstract

The first and second generation tests for hepatitis B antigen(HBsAg), namely, gel diffusion, counterimmunoelectrophoresis are considered relatively insensitive tests. But it is not clear which of the more sensitive third generation tests would be most suitable for routine use. Because radioimmunoassay(RIA) is generally accepted as being the most sensitive method currently available, sensitivity and specificity of other third generation tests including ELISA and RPHA with different commercial kits were compared with the results of RIA. Comparisons were also made in terms of procedural simplicity, amount of time required to complete the test and cost of the assay kit. Study subjects consisted of 235 in-patient blood samples requested for HBsAg test and 206 blood samples from voluntary blood donors in Yonsei University Medical Center during the period of 5 months from July to December in 1980. The results are summarized as follows; 1) The seropositive cases for HBsAg in 235 patients were 86(36.6%) by RIA(Abbott) and 85(36.2%) by ELISA(Abbott) (p>0.05). 2) The detection rates of HBsAg in 59 positive samples by RIA were 57(96.6%) by Cellognost(Behring), 58(98.3%) by Serodia(Fujizoki), and 54(91.5%) by Raphadex B(Ortho) (p>0.05). 3) Of the 130 HBsAg negative samples by RIA, 11(8.4%) by Cellognost(Behring), 6(4.6%) by Serodia(Fujizoki) and 4(3.1%) by Raphadex B(Ortho) were positive (p>0.05). 4) Seropositive rates for HBsAg in 206 voluntary blood donors were 5.2% by CIEP and 16.4% to 20.4% by different kits for RPHA (p<0.05). The RPHA appears to be a very sensitive, rapid, and simple method for detecting HBsAg. However, false positive results occurring with some sera needs confirmation by specific inhibition or by testing with another methods. In terms of sensitivity and specificity, ELISA appears to be a satisfactory method which can be used in clinical laboratory. Also it can circumvents the high cost and problems inherent in RIA systems.