Serum immunoreactive erythropoietin in children with acute leukaemia at various stages of disease--and the effects of treatment.

Most children with leukaemia are anaemic at diagnosis and at various times during treatment. Serum erythropoietin (EPO) was estimated in 27 children with acute leukaemia (n = 26) or lymphoma (n = 1) at diagnosis (n = 16), in relation to treatment with high-dose methotrexate (MTX, n = 11) or cytosine arabinoside (Ara-C, n = 8), and during oral maintenance therapy (n = 10). At diagnosis, in children with anaemia serum EPO was increased, and was inversely related to haemoglobin (Hb). After treatment with high-dose MTX, in some children serum EPO increased where Hb was unchanged or increased. After treatment with high-dose Ara-C, Hb declined, and serum EPO increased markedly in everyone. During oral maintenance therapy without significant anaemia, serum EPO was slightly increased in some children. In conclusion, children with leukaemia respond to anaemia with increased serum EPO concentration, but in relation to treatment with high-dose MTX and Ara-C, additional mechanisms may influence the EPO concentration.