HEPARIN-INDUCED THROMBOCYTOPENIA - AN IMPROVED METHOD OF DETECTION BASED ON LUMI-AGGREGOMETRY

Heparin-induced thrombocytopenia (HIT) is a recognized complication of heparin administration, Early detection of this syndrome is essential in the prevention of immune-mediated thromboembolic sequelae. The C-1 4-serotonin release assay (SRA) has been used in reference laboratorie s to identify sera from patients on heparin therapy capable of inducin g platelet dense granule release. In an attempt to improve existing me thodologies, we employed luminographic detection of platelet-dense gra nule ATP release as an endpoint of HIT antibody-mediated platelet acti vation, Sera tested included 10 SRA confirmed positive and five SRA co nfirmed negative samples (to establish the assay), five samples from p atients with thrombocytopenia not on heparin therapy and 34 patients s uspected of HIT syndrome. All SRA confirmed positive sera (n = 19) wer e positive by the luminographic procedure, 24/26 SRA confirmed negativ e sera and five sera from thrombocytopenic patients not on heparin the rapy were negative using luminography. Two of four sera yielding equiv ocal SRA results were found to be positive by the luminographic techni que, The data suggest that the use of a luminaggregometer in the coagu lation laboratory to detect HIT antibody-induced platelet activation i s a reliable alternative to the SRA. The luminographic procedure is bo th rapid and sensitive, and does not require the use of biohazardous r adio-isotopes.