title: Determination of functional iron deficiency status in haemodialysis patients in central South Africa.
abstract: BACKGROUND
  Functional iron deficiency (FID) is characterized by adequate body iron stores with an inadequate rate of iron delivery for erythropoiesis. In chronic kidney failure (CKD), iron availability is best assessed using the percentage of hypochromic red cells (%Hypo). The aim of our study was to determine the FID status of haemodialysis patients in central South Africa, using the %Hypo analyte and to evaluate the ability of the currently used biochemical tests, transferrin saturation (TSat) and serum ferritin to diagnose FID.
  
  
  METHODS
  For this study, 49 patients on haemodialysis were recruited. Haemoglobin (Hb), mean cell volume (MCV) and %Hypo were measured on the Advia 2120i. Biochemical analytes (serum ferritin, TSat) and C-reactive protein (CRP) levels were also recorded.
  
  
  RESULTS
  Of the 49 participants, 21 (42.9%) were diagnosed with FID (%Hypo >6%). A large number of patients (91.8%) were anaemic. The TSat demonstrated poor sensitivity and specificity for diagnosing FID compared with %Hypo. The use of %Hypo (rather than TSat) to guide intravenous iron use spared 16 patients the potential harmful effects thereof.
  
  
  CONCLUSIONS
  Using %Hypo as a single analyte to diagnose FID will lead to more appropriate use of limited resources and a reduction in treatment-related complications.
authors.affiliation: Faculty of Health Sciences, Department of Haematology and Cell Biology, University of the Free State, Bloemfontein, South Africa.
authors.forename: L
authors.initials: L
authors.lastname: Haupt
authors.affiliation: Faculty of Health Sciences, Department of Haematology and Cell Biology, University of the Free State, Bloemfontein, South Africa.
authors.forename: R
authors.initials: R
authors.lastname: Weyers
mesh_terms: D000328:Adult; D000747:Anemia, Hypochromic / Q000097:blood / Q000175:diagnosis*; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000175:diagnosis; D004912:Erythrocytes / Q000737:chemistry; D005293:Ferritins / Q000097:blood; D006403:Hematologic Tests / Q000379:methods*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007501:Iron / Q000097:blood; D000090463:Iron Deficiencies; D007676:Kidney Failure, Chronic / Q000097:blood*; D008875:Middle Aged; D006435:Renal Dialysis / Q000009:adverse effects; D012680:Sensitivity and Specificity; D013019:South Africa; D014168:Transferrin / Q000032:analysis*
chemical_list: D006454:Hemoglobins; D014168:Transferrin; D005293:Ferritins; D007501:Iron
keywords: Functional iron deficiency; chronic kidney disease; haemodialysis; percentage of hypochromic red cells