Analytical performance of three diagnostic reagents for HBsAg on an automatic ELISA analyzer.

PURPOSE: We conducted performance tests of three HBsAg ELISA diagnostic reagents using an Addcare 600 (Yantai Addcare Bio-tech Limited Company) and studied the consistency between the qualitative results and chemiluminescent microparticle immunoassay (CMIA) results. METHODS: Diagnostic kits (ELISA) for HBsAg manufactured by INTEC ("A"), KHB ("B") and Wantai ("C") were tested on an Addcare 600 to evaluate their intermediate precision, repeatability, and C50. Furthermore, three ELISA detection systems and a quantitative test kit for HBsAg (Abbott) were employed to screen 1000 serum samples, while CMIA reactive samples were used to perform the confirmatory tests. The evaluation indexes of the ELISA reagent performances were calculated. RESULTS: The intermediate precision and repeatability of each system were <14% and <9%, respectively, while C50 was 0.105-0.115 IU/mL. The sensitivities of A, B, and C were 98.70%, 99.28%, and 99.13%, respectively, while their specificities were 98.06%, 99.03%, and 97.42%, respectively. The Youden indexes were 96.76%, 98.31%, and 96.55%, respectively, while the kappa values were 0.965 (P=.000), 0.981 (P=.000), and 0.967 (P=.000), respectively. CONCLUSION: The combination of Addcare 600 with the three reagents could meet the clinical requirement. Reagent B demonstrated the best performance. Although the results consistency among the three systems and CMIA was good, our findings suggest that ELISA should be combined with a confirmatory test to exclude false-positive and false-negative results caused by low HBsAg levels.