Comprehensive analysis of single comparison and composite detection on samples with HBsAg around ELISA cut-off value

Abstract

Objective To investigate the retesting borderline range of hepatitis B surface antigen (HBsAg) negative samples and the reexamination range of weakly positive samples above the critical value determined with enzyme-linked immunosorbent assay (ELISA), and the performance of single comparison with electrochemiluminescence immunoassay (ECLIA) qualitative detection and two half-and-half composite detection with latex immunochromatographic assay. Methods Serum HBsAg was detected with ELISA reagents made in China. Negative samples were retested with ELISA. Samples with HBsAg around ELISA cut-off value were compared with ECLIA qualitative detection and two half-and-half detections of the borderline samples were made with latex immunochromatographic assay. Results HBsAg determination around ELISA cut-off value samples were of a certain degree of false negative (positive) rate. Anti-HBs positive 682/1020 (66.86%) and all negative 345/1020 (33.82%) in one side of 0.073 5≤ A<0.105 were found in two half-and-half examinations with latex immunochromatographic test, and in another 0.105 ≤ A<1.000 side anti-HBe or/and anti-HBc positive 329/333 (including 36 cases with HBeAg positive) (99.80%) were major. Conclusions HBsAg ELISA borderline samples would be carried on qualitative detection with ECLIA as a comparison. If comprehensive analysis of two half-and-half examinations with latex immunochromatographic test were used, retesting of the most boardline samples would be omitted. Key words: Enzyme-linked immunosorbent assay; Hepatitis B surface antigens/AN