In US: 510(k) Cleared for In Vitro Diagnostic Use for Plasma only. Enzyme Immuno-assay designed for measuring heparin-dependent antibodies of the IgG isotype, in human plasma. This assay measures only the IgG isotype, reported as the most associated with the clinical complications of heparin dependent antibodies (HIT/HITT), allowing confirmation of the diagnosis of HIT/HITT or its clinical suspicion. However, some cases associated with only IgM and/or IgA isotypes can be missed.