Aptiva APS IgG Reagent; Aptiva APS IgM Reagent

The Aptiva APS IgG and IgM Reagents are immunoassays that detect anti-cardiolipin (aCL) and anti-beta 2 glycoprotein 1 (aβ2GPI) autoantibodies in human serum using particle-based multi-analyte technology. They are used to aid in diagnosis of primary and secondary antiphospholipid syndrome (APS) when used with other clinical and laboratory findings on the Aptiva automated analyzer system.

The devices use fluorescent immunoassay on paramagnetic microparticles, whereas predicate devices use chemiluminescent or enzyme-linked immunosorbent assay (ELISA) methodologies. Both employ similar magnetic particle suspension coated with cardiolipin and β2GPI antigens. The Aptiva reagents measure median fluorescent intensity (MFI) converted to Fluorescent Light Units (FLU), with a cutoff of 5.00 FLU for both IgG and IgM assays.

Performance was evaluated per CLSI EP05-A3 (precision), CLSI EP06 (linearity), CLSI EP07-A2 (interference), CLSI EP17-A2 (detection capability), and CLSI EP28-A3c (reference intervals). No ISO, IEC, or ASTM standards are explicitly cited in this summary.

The devices have the same intended use and assay principle (detection of aCL and aβ2GPI antibodies for APS diagnosis) as predicate devices. Method comparison studies demonstrated good agreement with predicates: 93.1% total agreement for aCL IgG, 88.9% for aβ2GPI IgG, 89.8% for aCL IgM, and 84.8% for aβ2GPI IgM. Clinical sensitivity and specificity (53-54% sensitivity, 97-99.5% specificity for IgG; 25-27% sensitivity, 97.5-98.5% specificity for IgM) are comparable to predicate performance, and analytical performance characteristics (precision, linearity, limit of detection/quantitation) demonstrate reliable quantitation across the measuring ranges.