Clinical Efficacy of Platelet Transfusion

Inclusion Criteria: * Patients with haematological malignancies or bone marrow aplasia with severe thrombocytopenia due to bone marrow failure related to the disease or treatments received * Severe thrombocytopenia requiring transfusion * Patient able to self-assess bleeding events * Non-opposition of the subject to participate in the study * Registered with the French social security system or benefiting from such a system. Exclusion Criteria: * Acute promyelocytic leukaemia * Curative dosage of anticoagulants * Treatment with antiplatelet agents * Patient with proven thrombocytopenia of immunological origin, or disseminated intravascular coagulation * Patients with a clinically significant haemorrhagic event (WHO grade 2) in the 48 hours prior to transfusion * Indication for deplasmatised, cryopreserved and reduced-volume PCs * Patient refusing transfusion of labile blood products * Pregnant women or breast-feeding mothers * Adults subject to a legal protection measure or unable to express their consent * Persons deprived of their liberty by a judicial or administrative decision; persons under compulsory psychiatric care; persons admitted to a health or social care institution for purposes other than research * Subject in the exclusion period of another study