Background: The determination of antibody to hepatitis B core antigen (HBcAb) has become an important means of evaluating the risk factors of de novo hepatitis B virus (HBV) infection before starting intensive immunosuppressive drug therapies. Four dominant HBcAb determination reagents used in Japan were evaluated with HBcIgM, HBsAg, HBsAb, HBeAb, and HBV DNA reagents in order to study their clinical utility.
Methods: Four kinds of HBcAb reagent kits (HBcAb Total and HBcAb-IgG reagent) were evaluated with 526 clinical specimens, including 344 negative specimens, at Osaka University Hospital. The dynamic range of each kit was evaluated by testing serially diluted serum from pooled sera with high HBcAb concentration.
Results: The reagent that showed the largest dynamic range was the Lumipulse HBcAb-N (HBcAb-IgG reagent). Regarding clinical sensitivity and specificity, Centaur HBcAb (HBcAb Total reagent) gave several "doubtful negative" results and ARCHITECT HBcIl (HBcAb Total reagent) had the most discrepant positive results. By comparing the cut-off-index distribution of negative specimens using a parameter of "distance from the mean to the cut-off divided by the SD", Centaur was determined to be the best (distance/SD = 12.65), with Lumipulse and Elecsys Anti-HBc (HBcAb Total reagent) in the second group (8.13 and 7.00, respectively), and ARCHITECT rated as the worst (3.25).
Conclusions: In this evaluation, Elecsys and Lumipulse HBcAb kits showed good clinical sensitivity and specificity and were considered to be suitable for evaluating the risk factors of de novo HBV infection.