Department of Internal Medicine, Division of Hematology, Fatih University, Fatih University, Ankara, Turkey.
Clin Appl Thromb Hemost. 2012 Jan-Feb;18(1):92-5. doi: 10.1177/1076029611405789. Epub 2011 May 17.
Pseudothrombocytopenia (PTCP) is a laboratory event of platelet clustering related to drugs used for anticoagulation. This condition is engendered by autoantibodies against platelets in usually EDTA-anticoagulated blood. Pseudothrombocytopenia has no clinical significance but when evaluated as true thrombocytopenia, this misconception may lead to unnecessary diagnostic procedures. Heparin-induced thrombocytopenia with thrombosis (HITT) is a complication of heparin treatment caused by heparin platelet factor 4 (HPF-4) antibodies, leading to platelet activation and hypercoagulability. In our study, 48 patients with PTCP and 36 healthy volunteers were included. Heparin platelet factor 4 antibody positivity was detected in 12 patients from PTCP group; nobody from control group had. Citrated serum samples and peripheral blood smears showed normal platelet count. Of the 4 patients using heparin derivative, 1 (2.1%) had antibody positivity but without any bleeding symptoms. In conclusion, HPF-4 antibody positivity might be a risk factor for PTCP. Clinicians should be aware of this kind of condition.
假性血小板减少症 (PTCP) 是一种与抗凝药物相关的血小板聚集引起的实验室现象。这种情况通常发生在 EDTA 抗凝的血液中，由针对血小板的自身抗体引起。假性血小板减少症没有临床意义，但如果被评估为真正的血小板减少症，这种误解可能会导致不必要的诊断程序。肝素诱导的血小板减少症伴血栓形成 (HITT) 是肝素治疗的一种并发症，由肝素血小板因子 4 (HPF-4) 抗体引起，导致血小板激活和高凝状态。在我们的研究中，纳入了 48 例 PTCP 患者和 36 名健康志愿者。在 PTCP 组的 12 名患者中检测到肝素血小板因子 4 抗体阳性；对照组没有人阳性。枸橼酸盐血清样本和外周血涂片显示血小板计数正常。在使用肝素衍生物的 4 名患者中，有 1 名（2.1%）抗体阳性，但没有任何出血症状。总之，HPF-4 抗体阳性可能是 PTCP 的一个危险因素。临床医生应注意这种情况。
