Aptiva APS IgA Reagent

The Aptiva APS IgA Reagent is an immunoassay that uses particle-based multi-analyte technology to measure anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) IgA autoantibodies in human serum. It aids in diagnosing primary and secondary antiphospholipid syndrome (APS) when used with other laboratory and clinical findings on the Aptiva System analyzer.

The device uses fluorescent immunoassay with paramagnetic microparticles coated with cardiolipin and β2GPI antigens, measured by median fluorescent intensity (MFI) on the Aptiva platform. This differs from the predicate's chemiluminescent technology and uses three calibrator levels versus two, with a clinical cutoff of 5.00 FLU versus 20.0 CU.

Studies followed CLSI EP05-A3 (precision), CLSI EP06 (linearity), CLSI EP07 (interference), CLSI EP17-A2 (detection capability), and CLSI EP28-A3c (reference intervals). The device was validated against disease control samples and characterized patient cohorts including APS, infectious disease, and autoimmune disease controls.

Substantial equivalence is based on identical intended use and assay principle as predicates QUANTA Flash aCL IgA and QUANTA Flash β2GPI IgA (K120817) for semi-quantitative APS diagnosis. Clinical performance shows sensitivity of 31.4% and 32.0% and specificity of 97.8% and 98.5% for aCL IgA and aβ2GPI IgA respectively, with method comparison demonstrating 90.2–97.1% positive percent agreement and 97.2–98.0% negative percent agreement to predicates.