title: Heparin platelet factor 4 antibody positivity in pseudothrombocytopenia.
abstract: 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.
authors: Department of Internal Medicine, Division of Hematology, Fatih University, Fatih University, Ankara, Turkey.
authors: Ozlem Sahin
authors: OS
authors: Balcik
authors: Derya
authors: D
authors: Akdeniz
authors: Handan
authors: H
authors: Cipil
authors: Sema
authors: S
authors: Uysal
authors: Ayse
authors: A
authors: Isik
authors: Ali
authors: A
authors: Kosar