Heparin platelet factor 4 antibody positivity in pseudothrombocytopenia.

Ozlem Sahin Balcik, Derya Akdeniz, Handan Cipil, Sema Uysal, Ayse Isik, Ali Kosar

Department of Internal Medicine, Division of Hematology, Fatih University, Fatih University, Ankara, Turkey.

Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis 2012 Jan-Feb

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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.

Citation

Ozlem Sahin Balcik, Derya Akdeniz, Handan Cipil, Sema Uysal, Ayse Isik, Ali Kosar. Heparin platelet factor 4 antibody positivity in pseudothrombocytopenia. Clinical and applied thrombosis/hemostasis : official journal of the International Academy of Clinical and Applied Thrombosis/Hemostasis. 2012 Jan-Feb;18(1):92-5