Erythromelalgic Thrombotic Thrombocythemia (ETT) and Hemorrhagic Trombocythemia (HT) in Patients with Essential Thrombocythaemia (ET) and Polycythaemia Vera (PV)

Abstract

We analysed between 1908 and 1985 of two hundred cases of thrombocythemia from the literature between 1908 and 1985. Erythromelalgic, acrocyanotic ischemia and digital gangrene, cerebral or coronary ischemic events (erythromelalgic thrombotic thrombocyhemia: ETT) in 99 thrombocythemia patients (essential thrombocythemia: ET N=67 and polycythemia vera: PV N=32) occured at platelet counts in excess of 400 × 10 9 /L. Hemorrhagic complications at time of presentation of hemorrhagic thrombocythemia (HT) in 100 HT patients included melana and/or hematemesis, skin bleedings (bruises, subcutaneous hematomas, painfull hematomas after trauma, ecchymoses, but not petechiae, epistaxis and gum bleeding and secondary bleeding after trauma or surgery. ETT occurred at an early stage of thrombocythemia with a mean platelet count of 1110+477 × 10 9 /L, whereas HT occurred at significantly higher platelet counts in excess of 1000 × 10 9 /L with a mean platelet count of 2016+1070 × 10 9 /L. HT patients frequently had a previous history of ETT or paradoxical occurrences of both thrombosis and bleeding (ETT/PHT). The degree of thrombocythosis determined the sequential occurrence of ETT, HT in ET and PV patients. Hypersensitive thrombocythemic platelets (sticky platelets) are involved in the etiology of platelet-mediated thrombosis at platelet counts above 400 × 10 9 /L whereas bleedings at high platelet count is related to an acquired von Willebrand syndrome processes on top of a blood clot retraction disturbance with erythrocyte fall out, that causes painful subcutaneous hematomas with a central swelling (clot) after a blow, trauma and secondary bleeding after surgery in thrombocythemia patients.