Vaskulárna medicína 1/2020

HIT – functional assay for the determination of heparin-induced thrombocytopenia

Background: Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of heparin therapy (both unfractionated heparin and low molecular weight heparin) (1). The diagnosis of HIT is based on a combination of clinical findings, 4Ts scores and laboratory tests (2). Methods: In our study, we examined a group of 47 patients with suspected HIT. Samples of all patients were analyzed in a first step by some immunoassay (ID-PaGIA Heparin/PF4, HemosIL-Acustar HIT IgG, ZYMUTEST HIA Monostrip IgG) to detect the presence of antibodies against heparin-PF4 complex (platelet factor 4). When the immunoassay was positive, the sample was subsequently analyzed for HIT by the HIT Alert function assay. Definitely, the diagnosis of HIT can be made only after a positive functional test result. Results: The sample consisted of 47 samples of patients with suspected HIT, who were evaluated by 34 immunoassays. Further testing of these samples with a functional flow cytometry assay - HIT Alert kit 16 samples were positive and 18 samples were negative. Conclusion: Clinical findings, 4Ts scores, the results of the immunoassay and functional test can significantly improve the prognosis of the disease.

Keywords: heparin-induced thrombocytopenia (HIT), heparin / PF4 complex (platelet factor 4), immunological and functional assays