Mild renal dysfunction is sufficient to induce erythropoietin deficiency in patients with unexplained anaemia

Current guidelines suggest that anaemia due to erythropoietin deficiency al most exclusively occurs with creatinine concentrations of at least 177 mu m ol/l or above. The aim of this prospective case control pilot study was to evaluate whether borderline renal function or mild renal dysfunction with c reatinine concentrations well below 177 mu mol/l is sufficient to induce in adequate erythropoietin secretion. Patients referred for work-up of otherwi se unexplained anaemia with mildly abnormal creatinine concentrations (104- 129 mu mol/l; study group: eight patients) and patients referred for work-u p or therapy of other diseases who also presented with anaemia but normal c reatinine levels (<100 mu mol/l; control group: nine patients matched for g ender, age and degree of anaemia) were included. All but two patients in th e control group had bone marrow biopsies to exclude other pathologies. Mild renal dysfunction las evidenced by creatinine concentrations between 100 a nd 140 mu mol/l, median concentration 112 mu mol/l) was found to be suffici ent to induce inadequate erythropoietin secretion. The physiologic hemoglob in-dependent erythropoietin regulation demonstrated in the control group wa s abolished in the study group. Patients with mild renal dysfunction and un explained anaemia should be investigated for erythropoietin concentration. If the erythropoietin concentration is found to be inadequate for the degre e of anaemia, substitution therapy should be considered. (C) 2000 Published by Elsevier Science B.V. All rights reserved.