title: [Fundamental and clinical evaluation of hepatitis B virus core-related antigen assay by LUMIPULSE f].
abstract: A sensitive chemiluminescence enzyme immunoassay (CLEIA) has been developed for hepatitis B virus (HBV) core-related antigens (HBcrAg) detection. The HBcrAg is designated as the precore/core gene products including HBeAg. The aim of this study is to evaluate reproducibility of HBcrAg and correlation with HBV-DNA in serum using the automatic LUMIPULSE f to estimate an assay suitable for general laboratory use. In this study, we demonstrated that HBcrAg assay had highly intra-assay reproducible [coefficients of variation(CVs); 2.8-5.2%] and inter-assay reproducible [CVs; 3.9-9.1%]. When the cutoff value was tentatively set at 1 kU/ml, all healthy controls (HBsAg/HBV-DNA negative; n=100) and anti-HCV antibody-positive (n=50) sera were identified as negative. The assay showed a detection limit of 0.5 kU/ml using four serially diluted HBV high-titer sera, indicating higher sensitivity than HBV-DNA (transcription-mediated amplification). The HBcrAg concentration correlated positively with serum HBV-DNA (n=125, r = 0.860, p < 0.0001) regardless of HBeAg, although the HBcrAg levels were higher in HBeAg-positive group than in HBeAg-negative group. In the natural course of HBV infection, the HBcrAg concentration usually changed in accordance with HBV-DNA levels, however during lamivudine therapy the change of HBcrAg was more gradual than that of HBV-DNA. In conclusion, HBcrAg concentration provides a reflection of HBV virus load equivalent to HBV-DNA level, and the assay therefore offers a simple method for monitoring hepatitis B patients.
authors.affiliation: Department of Central Clinical Laboratory, Nagoya City University Hospital, Nagoya.
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kazumi
authors.initials: K
authors.lastname: Takagi
authors.forename: Kumiko
authors.initials: K
authors.lastname: Hiramatsu
authors.forename: Hatsue
authors.initials: H
authors.lastname: Naganuma
authors.forename: Takayasu
authors.initials: T
authors.lastname: Iida
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Takasaka
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizokami
mesh_terms: D004279:DNA, Viral / Q000097:blood; D006512:Hepatitis B Core Antigens / Q000032:analysis*; D019694:Hepatitis B, Chronic / Q000276:immunology; D006801:Humans; D008163:Luminescent Measurements; D015203:Reproducibility of Results
chemical_list: D004279:DNA, Viral; D006512:Hepatitis B Core Antigens