ABSTRACT
Physiopathology of anaemia and thrombocytopaenia in children with malignancy: the role of erythropoietin and thrombopoietin. The aim of our work was to determine the role of an impaired erythropoietin (EPO) and thrombopoietin (TPO) production in development of, respectively, the anaemia and thrombocytopaenia in children with malignancy. Simultaneous dosage of EPO and of serum transferrin receptor have shown that anaemia in these patients is of central origin but related to a blunted EPO production. The same observation has been made in children at diagnosis either with acute leukaemia or solid tumour as well as during chemotherapy. In patients under maintenance chemotherapy for acute leukaemia, using long-term bone marrow cultures, we could detect an impaired supportive capacity of bone marrow micro-environment for erythropoiesis. The last part of this work has shown that thrombocytopaenia associated with acute leukaemia in children is accompanied by very high TPO levels as observed in other thrombocytopaenia of central origin, excepted in patients with acute leukaemia of myeloid origin. In these patients, TPO levels are inappropriately low in most cases. The low TPO levels are related to the presence of TPO receptor-expressing myeloid leukaemic cells, suggesting that TPO is "consumed" by blast cells expressing a functional TPO receptor.
