Laboratory Testing for Hit Antibodies: How Much Class Do We Need?.

Abstract HIT is usually caused by platelet-activating antibodies of IgG class that bind to neoepitopes on platelet factor 4 (PF4) bound to heparin or certain other polyanions. Commercial enzyme-immunoassays (EIAs), however, measure PF4/polyanion-reactive antibodies of IgA and IgM class, in addition to IgG class antibodies. This raises the question: Does the detection of these IgA and IgM class antibodies improve HIT assay …