ASSESSING IRON STATUS IN CHILDREN WITH CHRONIC-RENAL-FAILURE ON ERYTHROPOIETIN - WHICH MEASUREMENTS SHOULD WE USE

Iron deficiency severely limits the efficacy of recombinant human eryt hropoietin (EPO). In order to determine how best to identify and monit or children at risk of developing iron deficiency, we serially measure d several parameters of iron status in nine children before and during a 24-week period of EPO therapy. Serum ferritin was the best predicto r of development of iron deficiency, five of the nine children develop ed iron deficiency, characterised by a poor haemoglobin response or ev idence of microcytosis and hypochromia; all had a serum ferritin of 60 mu g/l or less at the start of EPO. Haemoglobin response was also rel ated to change in mean red cell volume (MCV); a falling MCV, irrespect ive of absolute value, accompanying a poor response to EPO. Iron treat ment in five children resulted in significant improvements in haemoglo bin and iron status parameters. Although MCV remained low, there was a marked increase in red cell volume distribution width after iron, whi ch may be of value in monitoring the response to iron therapy. We sugg est that children with a serum ferritin of 60 mu g/l or less and those who develop a falling MCV during EPO treatment should receive high-do se oral iron supplementation before and during treatment with EPO.