Comparison of three measurement methods applying in HBsAg weakly positive samples

Objective To compare the result coincidence of HBsAg detected with gold immunochromatography assay (GICA),enzyme linked immunosorbent assay (ELISA) and microparticle enzyme immunoassay (MEIA) in HBsAg weakly positive samples,and to understand the applicable value by comparing the diadynamic criteria including specificity and sensitivity.Methods The HBsAg weakly positive serum samples were detected with GICA,ELISA and MEIA simultaneously and the results were compared.Results The result coincidence of HBsAg detected with three methods was 74.3%. Among them,the coincience rate of ELISA and MEIA was 95.2%,and the one of GICA and MEIA was 76.2%. The diagnosing efficiency of GICA detecting HBsAg weakly positive samples was not ideal.Conclusion The sensitivity and specificity of GICA were both 81.3%,significantly lower than those of ELIA and MEIA. GICA is only used to screen HBsAg because of its high omission rate and misdiagnosis rate in detection of HBsAg weakly positive samples. In the situation,GICA should be combined with ELISA method. Because the sensitivity and specificity of ELISA were a little lower than those of MEIA,MEIA rechecking should be performed when OD value is near to cutoff value.