title: Thrombocytopenia with thrombocytopathy possibly related to abnormalities of intracellular Ca++ fluxes and followed by the development of leukaemia.
abstract: A patient is described who presented a thrombocytopenia with thrombocytopathy followed by the development of a leukaemia. The disorder was characterized by decreased aggregation in the presence of ADP, and a lack of aggregation in the presence of arachidonic acid, natural endoperoxide or collagen. In parallel, 14C-serotonin release was severely decreased or nil in response to these inducers. Thrombin induced a slightly decreased aggregation and a normal 14C-serotonin release. Thromboxane B2 (T X B2) synthesis was normal after stimulation by arachidonic acid, natural endoperoxide or thrombin showing a normal arachidonate metabolism. In addition, the mepacrine test showed no significant decrease of the number of dense bodies with an average of 4.6 per platelet (versus 5.4 +/- 0.8 sd in controls). Stimulation by ionophore A 23187 failed to induce aggregation, 14C-serotonin release, or T X B2 synthesis. Furthermore, in the presence of EDTA, A 23187 did not provoke activation as reflected by 14C-serotonin release or T X B2 synthesis. Thus, in this case of thrombocytopathy, the hypothesis of abnormal intracellular Ca++ fluxes responsible for the defective platelet release phenomenon, was suggested.
mesh_terms: D000244:Adenosine Diphosphate / Q000494:pharmacology; D001791:Blood Platelet Disorders / Q000097:blood* / Q000150:complications; D001792:Blood Platelets / Q000378:metabolism*; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000097:blood*; D004492:Edetic Acid / Q000494:pharmacology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007938:Leukemia / Q000097:blood* / Q000209:etiology; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D011796:Quinacrine; D012701:Serotonin / Q000097:blood; D013921:Thrombocytopenia / Q000097:blood* / Q000150:complications; D013929:Thromboxane B2 / Q000097:blood
chemical_list: D012701:Serotonin; D000001:Calcimycin; D013929:Thromboxane B2; D000244:Adenosine Diphosphate; D004492:Edetic Acid; D011796:Quinacrine; D002118:Calcium