Look K A, Sahud M, Flaherty S, Zehnder J L
Department of Pediatric Hematology/Oncology, Stanford University Medical Center, California 94305, USA.
Am J Clin Pathol. 1997 Jul;108(1):78-82.
Thrombosis occurs in an unpredictable subset of patients with heparin-induced thrombocytopenia (HIT). The diagnosis of HIT requires clinical suspicion and laboratory confirmation. Although the "gold-standard" diagnostic test is considered to be the serotonin release assay (SRA), most laboratories use heparin-induced platelet aggregation (HIPA), which is highly specific but reported to be less sensitive than the SRA. Recently, the heparin-platelet factor 4 (PF4) enzyme-linked immunosorbent assay (ELISA) has been reported to have comparable sensitivity to the SRA. We compared the HIPA and PF4 ELISA in serum samples from 146 patients examined for HIT and assessed whether either test predicted thrombotic risk. Results for 81 patients were positive for HIPA, PF4 ELISA, or both. Of these, 91% were HIPA-positive, while only 60% were PF4 ELISA-positive. Clinical information was available on 63 patients, 17 of whom had thrombotic events (10 venous, 6 arterial, and 1 both). Neither the HIPA nor the PF4 ELISA predicted thrombotic risk, but the HIPA proved to be a more sensitive test for laboratory confirmation.
血栓形成发生在肝素诱导的血小板减少症（HIT）患者中不可预测的一部分。HIT的诊断需要临床怀疑和实验室确认。尽管“金标准”诊断试验被认为是血清素释放试验（SRA），但大多数实验室使用肝素诱导的血小板聚集试验（HIPA），其特异性很高，但据报道比SRA敏感性低。最近，肝素-血小板因子4（PF4）酶联免疫吸附测定（ELISA）据报道与SRA具有相当的敏感性。我们比较了146例接受HIT检查患者血清样本中的HIPA和PF4 ELISA，并评估了这两种试验是否能预测血栓形成风险。81例患者的HIPA、PF4 ELISA或两者结果呈阳性。其中，91%为HIPA阳性，而PF4 ELISA阳性仅为60%。有63例患者的临床信息，其中17例发生了血栓事件（10例静脉血栓、6例动脉血栓和1例动静脉血栓）。HIPA和PF4 ELISA均不能预测血栓形成风险，但HIPA被证明是实验室确认的更敏感试验。
