In patients who have stainable iron in the bone marrow an elevated plasma transferrin receptor value may reflect...

Elevated transferrin receptor (TfR) concentration may be either because of iron deficiency or an increased rate of erythropoiesis. We have studied the relationship between elevated TfR and advanced RBC and reticulocyte indices in an unselected population of hospitalized patients. The iron status in 95 consecutive hospitalized patients was assessed using bone marrow aspirate examination and analysis of the RBC and reticulocyte indices was performed using the Advia 120 haematology system. Of the 95 patients, a total of 17 had no stainable iron in the bone marrow and most of them also had an elevated TfR. Of the 78 patients with stainable iron stores, 15 also had an elevated TfR concentration (> or =2.4 mg/l). Six of them also had an elevated %HYPOm (> or =3.4%), and therefore were regarded as having functional iron deficiency. We evaluated the possible causes of elevated TfR concentrations in patients having stainable iron in the bone marrow, and this study suggests that functional iron deficiency explains a considerable proportion of these cases.