Architect hbsag assay

Standard of care virological parameters were analyzed by the local laboratory of the respective center. HBV DNA levels were determined using either the COBAS AmpliPrep/COBAS TaqMan (Roche Diagnostics, Mannheim, Germany) or the Aptima HBV Quant Assay running on the fully automated Panther^® system, following the manufacturer’s protocol (Hologic, Marlborough, MA, USA). The lower limit of quantification (LLOQ) is 20 IU/mL (1.3 log IU/mL); undetectable HBV DNA levels were set to 0.1 IU/mL (−1 log IU/mL) for statistical analyses. For the assessment of HBsAg level the ARCHITECT HBsAg assay (Abbott, North Chicago, IL, USA) with a LLOD of 0.05 IU/mL was used. Undetectable levels of HBsAg were set to 0.1 IU/mL (−1 log IU/mL) for statistical analyses. HBcrAg was measured by using the Lumipulse^® G HBcrAg Immunoreaction assay (Lumipulse^® G Fujirebio-Europe (LLOD 2 log U/mL, linear range ≥ 3 log U/mL)) according to the manufacturer’s protocol. HBcrAg comprises three proteins encoded by the precore/core gene of the HBV genome (HBeAg, HBcAg and the 22-kDa precore protein [p22cr/PreC]). For statistical analysis, HBcrAg levels < 2 log U/mL were calculated as 2 log U/mL.

HBsAg was quantified as previously described [4 (link)], using ARCHITECT HBsAg assay (Abbott, Chicago, IL, USA) according to manufacturer's instructions.

The status of HBV infection such as HBsAg, quantitative HBsAg (qHBsAg), hepatitis B e-antigen (HBeAg), anti-hepatitis B e-antibody (anti-HBe Ab) and HBV DNA were detected. The presence of HBsAg was determined using commercial assay kits (HBsAg, MEIA 3.0; Abbott, North Chicago, IL, USA). qHBsAg was quantified using ARCHITECT HBsAg assay (Abbott, Chicago, IL, USA) according to manufacturer's instructions. The lower limit of detection was 0.05 IU/ml. Serum HBeAg levels were measured by a microparticle enzyme immunoassay (AxSYM; Abbott). TheAxSYM assay result was based on the ratio of the sample (S) to the cut-off (Co) (S/Co ratio) for each sample and control. The positivity of HBeAg was defined as S/Co ratio ≧ 1.0 in accordance with the manufacturer's instructions. Serum HBV DNA levels were determined using a quantitative real-time PCR assay, the COBAS AmpliPrep-COBAS TaqMan HBV test (CAP-CTM; Roche Molecular Systems Inc., Branchburg, NJ, USA), with a lower detection limit of 12 IU/mL (70 copies/mL). Dilution was performed if HBV DNA levels were >10⁶ copies/mL.

HBV DNA was measured using a real-time PCR (Amplicor HBV Monitor Test, Roche Diagnostics, Mannheim, Germany). HBsAg and HBeAg levels were measured with the ARCHITECT HBsAg assay (Abbott Laboratories, Lake Forest, IL, USA) and AxSYM HBe 2.0 assay (Abbott), respectively. Anti-HBs and anti-HBe were determined by ARCHITECT qualitative assays (Abbott). Serum biochemical markers and alanine aminotransferase (ALT) were assayed using an Automatic Serum Analyzer (HITACHI 747, Japan).

HBsAg, HBeAg and HBV DNA levels were measured at a central laboratory with the ARCHITECT HBsAg assay (Abbott Laboratories, Lake Forest, IL, USA), AxSYM HBe 2.0 assay (Abbott), and either a standard generic HBV DNA assay (ACON Biotech Co. Ltd, Hangzhou, China) or the COBAS TaqMan HBV Test (Roche Molecular Diagnostics, Pleasanton, CA, USA). Anti-HBs and anti-HBe were assessed by ARCHITECT qualitative assays (Abbott).Alanine aminotransferase (ALT) was measured using a Hitachi Model 7600 Series Automatic Analyzer (Hitachi, Tokyo, Japan).