Thiele T, Althaus K, Greinacher A
Institut für Immunologie und Transfusionsmedizin, Ernst-Moritz-Arndt Universität, Sauerbruchstraße, 17489 Greifswald, Deutschland.
Internist (Berl). 2010 Sep;51(9):1127-32, 1134-5. doi: 10.1007/s00108-010-2594-5.
Heparin-induced thrombocytopenia (HIT) is an adverse drug reaction that carries an increased risk of thromboembolic complications. HIT is caused by platelet-activating antibodies directed against a complex of platelet factor 4 (PF4) and heparin. HIT typically manifests in the second week after initiation of heparin therapy with a platelet count reduction of more than 50% of the highest level after the start of heparin administration as well as thromboembolic events. The clinical probability can be calculated by the 4 T's score. The laboratory diagnosis of HIT is based on confirmation of PF4/heparin antibodies or on functional tests that provide evidence of heparin-dependent platelet-activating antibodies. A low 4 T's score and negative HIT test virtually rule out the presence of HIT. Patients with acute HIT require anticoagulation with a compatible anticoagulant in a therapeutic dose. The drugs currently available for this include the direct thrombin inhibitors argatroban, lepirudin, bivalirudin, and desirudin and the indirect factor Xa inhibitors danaparoid and fondaparinux.
肝素诱导的血小板减少症（HIT）是一种药物不良反应，会增加血栓栓塞并发症的风险。HIT是由针对血小板因子4（PF4）与肝素复合物的血小板活化抗体引起的。HIT通常在肝素治疗开始后的第二周出现，表现为血小板计数降至肝素给药开始后最高水平的50%以上，以及血栓栓塞事件。临床概率可通过4T评分计算。HIT的实验室诊断基于PF4/肝素抗体的确认或基于提供肝素依赖性血小板活化抗体证据的功能测试。低4T评分和HIT检测阴性实际上可排除HIT的存在。急性HIT患者需要使用治疗剂量的合适抗凝剂进行抗凝。目前可用于此的药物包括直接凝血酶抑制剂阿加曲班、比伐卢定、重组水蛭素和地西卢定，以及间接因子Xa抑制剂达那肝素和磺达肝癸钠。
