[Establishment of confirmatory test for HBsAb in serum of coexistence of hepatitis B surface antigen and antibodies to HBsAg].

OBJECTIVE:Establish a kind of confirmation method based on ELISA, and use to verify authenticity of HBsAb + in HBsAg + HBsAb + serum, pick and get rid of the false masculine gender the result, and avoid the mistake diagnosis. METHOD:Collect 60 pieces of serum whose thick degree of HBsAg at 1000 COI above tested by ECLIA as confirm serum, mixed the confirm serum of different dilution with HBsAb positive serum to screen and verify best thick degree of HBsAg. Collected 40 pieces of HBsAg + HBsAb + serum, ELISA tested the descend rate of HBsAb COI after neutralized with confirm serum in order to confirm authenticity of HBsAb + in pieces of HBsAg + HBsAb + serum. RESULT:When thick degree of HBsAg is 2000 COI, the performance of neutralization to HBsAb is best. The ELISA confirmatory test is fully consistent with the ECLIA method with true positive of 37 pieces of HBsAg + HBsAb + serum while false-positive of 3 pieces of serum. CONCLUSION:The ELISA confirm method is a simple, accurate and low cost initial validation method.