Patients with hematological malignancies are at increased risk of bleeding, especially during intensive chemotherapy. The aim of this study is to compare by thromboelastography changes during the intensive chemotherapy in patients with hematological malignancies.

Patients with hematological malignancies often develop low platelet counts either as a consequence of the disease or the treatment by chemotherapy or stem cell transplantation. Platelet transfusions are commonly given to raise any low platelet count and reduce the risk of clinical bleeding (prophylaxis) or stop active bleeding (therapy). The last studies have showed that many patients continue to experience bleeding, despite the use of platelet transfusions. Tranexamic acid is an antifibrinolytic agent. It reduces the breakdown of clots formed. This treatment is widely used in medicine (e.g. emergency, surgery, post-partum) and decreases blood loss and the use of red cell transfusions. The purpose of this study is to test different doses of tranexamic acid (full dose: 3g/day and half dose (1.5g/day) and to study its effect by thromboelastography, with the aim to determine the optimal posology for further clinical studies.

Inclusion Criteria:

• Patient affiliated to a social security regimen or beneficiary of the same
• Signed written informed consent form
• Confirmed diagnosis of a hematological malignancy and undergoing intensive chemotherapy
• Expected to experience hypoproliferative thrombocytopenia resulting in a platelet count of ≤10 G/L for ≥ 5 days

Exclusion Criteria:

• Pregnant women
• Patient under guardianship or deprived of his liberty or any condition that may affect the patient's ability to understand and sign the informed consent
• Refractoriness to platelet transfusion or requirement for a specific type of platelet transfusion (ABO-compatible, plasma-free)
• Ongoing anticoagulant therapy or antiplatelet therapy at the time of enrolment
• Treatment with any pro-coagulant agent within 48 hours of enrolment, or enrolment in other trials involving platelet transfusions, platelet growth factors, or presentation of a known hypercoagulable state
• Diagnosis of arterial or venous thromboembolic disease within the previous year
• Patient experiencing a bleeding event WHO grade ≥ 2 within 7 days before inclusion
• contra-indications to tranexamic acid (allergy, history of seizures, creatinine clearance < 30 mL/min)
• Refusing participation