Architect anti hbc 2

Data collection periods were divided into two sections, essentially because different serological test systems were in operation in the blood bank during each. Serological test systems used during the period 2012–2015 were: ARCHITECT anti-HIV/Agp24 (Combo), ARCHITECT Anti-HCV, ARCHITECT HBsAg Qualitative II and ARCHITECT Anti-HBc II, all of them from Abbott (Chicago, IL, USA). Samples with S/CO values > 1.0 are considered as reactive. Serological test systems used during the period 2017–2019 were: Laison XL Murex HIV Ab/Ag, Laison XL Murex HCV Ab (samples with S/CO values ≥ 1.0 are considered reactive), and Laison XL Murex HBsAg Quant (samples with UI/mL ≥ 0.050 are considered reactive), all of them from Diasorin (Saluggia, Italy). Data from July 2015 to December 2016 were not available and the present analysis corresponds to two non-continuous periods.

At the CML, all samples were re-analyzed by CMIA for HBsAg using ARCHITECT HBsAg (Abbott Laboratories, IL,USA) on ARCHITECT i4000SR platform according to the instructions of the manufacturer.
The samples were also analyzed with CMIA for anti-HBs and total anti-HBc using ARCHITECT anti-HBs and ARCHITECT anti-HBc II (Abbott Laboratories, IL, USA), respectively on the ARTCHITECT i4000SR machine following the manufacturer’s instructions. HBsAg positive samples were further analyzed for HBeAg and anti-HBe with the ARCHITECT HBeAg and ARCHITECT anti-HBe (Abbott Laboratories, IL, USA) assays. All HBsAg positive and isolated anti-HBc-positive samples were analyzed for antibodies against hepatitis delta virus (anti-HDV) with the ETI-AB-DELTA K-2 kits (Diasorin, Saluggia, Italy) according to the instructions by the manufacturer.

Blood donors were pre‐qualified with an HBsAg rapid test (95% limit of detection [LoD]: 5 IU/ml). HBV, HCV and HIV infection status in blood donations collected from HBsAg nonreactive donors was determined according to the serological and molecular screening and confirmatory testing algorithms implemented in the Dalian Blood Center.¹⁶ HBV DNA quantification was performed with an in‐house real‐time qPCR assay (95% LoD: 20 IU/ml).¹⁷ Refer to Appendix S1 for further details.
HBV DNA‐positive donations were tested for anti‐HBc with Elecsys® Anti‐HBc II (Roche Diagnostics), Architect® Anti‐HBc II (Abbott Laboratories, Abbott Park) and HISCL Anti‐HBc assay (Sysmex Corporation). Anti‐HBs was tested with Elecsys® Anti‐HBs II (Roche) and HISCL Anti‐HBs assay (Sysmex Corporation), anti‐HBe, and HBeAg with Elecsys® Anti‐HBe and HBeAg (Roche), and anti‐HDV with HDV‐IgG ELISA (WANTAI Bio‐Pharm).
The study was conducted according to the ethical guidelines of the 1975 Declaration of Helsinki and was approved by the Academic and Ethics Committee of Dalian Blood Center (EC‐20190731‐1226). All participants provided signed informed consent at donation time and during follow‐up.