Timeline of heparin‐induced thrombocytopenia seroconversion in serial plasma samples tested using an automated latex immunoturbidimetric assay

Introduction HIT is caused by platelet‐activating IgG that recognize multimolecular PF4/heparin complexes. HIT antibodies are generally detectable by PF4‐dependent enzyme immunoassay (EIA) and by platelet serotonin‐release assay (SRA) at the beginning of the HIT‐related platelet count fall. We determined whether an automated immunoassay for HIT, the latex immunoturbidimetric assay (LIA), also detects antibodies early during the course of HIT. The LIA was also used to evaluate a patient with putative SRA‐negative HIT.