Access anti-HBc IgM

The Access anti-HBc IgM assay is a chemiluminescent immunoassay that detects IgM antibodies to hepatitis B virus core antigen in serum and plasma samples from pediatric (ages 3–21) and adult populations. It is used as an aid in diagnosing acute or recent HBV infection when clinical symptoms are present and is run exclusively on the DxI 9000 Access Immunoassay Analyzer.

The candidate device uses paramagnetic particles coated with anti-human IgM monoclonal antibody and chemiluminescent detection with a single positive calibrator level. It differs from the predicate (ARCHITECT CORE-M) in instrumentation platform, sample volume (10 µL vs. 64 µL), calibrator design (1 level vs. 2 levels), test result reporting thresholds, longer reagent stability (56 vs. 30 days), and longer calibration frequency (56 vs. 30 days).

Studies were conducted following CLSI EP05-A3 (imprecision), CLSI EP09c 3rd Edition (matrix equivalence), CLSI EP07 3rd Edition (interfering substances), CLSI EP25-ED2 (reagent stability), and CLSI EP10-A3 AMD (intra-assay carryover) guidelines.

Substantial equivalence is established through identical intended use, same clinical indication, equivalent operating principle (two-step immunoassay for anti-HBc IgM detection), and comprehensive clinical and analytical performance data demonstrating 99.96% negative percent agreement and 50% positive percent agreement in prospective samples. The device showed comparable or superior seroconversion sensitivity and no clinically meaningful differences in pregnant or pediatric subpopulations despite differences in platform and technical specifications.