Comparison of ELISA and ECLIA in Testing HBsAg Weak Reactive Samples

Objective To compare the results of enzyme linked immunosorbent assay (ELISA) and electrochemiluminescence immunoassay (ECLIA) in testing HBsAg weak reactive samples. Methods 824 HBsAg weak reactive serum samples, which had been tested by ELISA and their S/CO were 0.7 ~ 5.0, were re-tested by the ECLIA. Results ①352 serum samples' S/CO were 0.7 ~ 0.99, the qualitation was negative by ELISA, but COI≥1.0 in 48 samples by ECLIA (positive), there were significant differences (P 0.05); ②432 serum samples' S/CO were 1.0 ~ LPC (the QC of the weak positive), the qualitation was positive by ELISA, but COI1.0 in 248 samples by ECLIA (negative), there were statistically significant differences (P 0.01); ③40 serum samples' S/CO were LPC ~ 5.0, the qualitation was positive by ELISA, and COI≥1.0 in all 5 samples by ECLIA (positive). Conclusion In the cases of 0.7S/CO0.99, ECLIA is better than ELISA in the sensitiveness; when S/CO are 1.0 ~ LPC, ELISA is effected by many factors, so it easily leads to false positive results and we shall analyze the reasons and further review; when S/CO are LPC ~ 5.0, both methods can accurately determine.