title: Laboratory variables for assessing iron deficiency in REDS-II Iron Status Evaluation (RISE) blood donors.
abstract: BACKGROUND
  Iron deficiency is common in regular blood donors. We evaluated the diagnostic sensitivity and specificity of red blood cell (RBC) hematology analyzer indices to assess iron status as a part of donor management.
  
  
  METHODS
  A total of 1659 male and female donors from the Retrovirus Epidemiology Donor Study-II (REDS-II) Donor Iron Status Evaluation (RISE) study who were either first-time/reactivated (FT/RA; no donations for 2 years) or frequent donors were recruited into a longitudinal study of regular donation of RBCs. Of these, 1002 donors returned 15 to 24 months later for a final assessment. Absent iron stores (AIS) was defined as plasma ferritin level of less than 12 μg/L. Logarithm of the ratio of soluble transferrin receptor to ferritin of at least 2.07 (≥97.5% in FT/RA males) was used to define iron-deficient erythropoiesis (IDE). Receiver operating characteristics analysis was performed to assess selected RBC indices (e.g., percentage of hypochromic mature RBCs, proportion of hypochromic mature RBCs [HYPOm], and hemoglobin [Hb] content of reticulocytes [CHr]) in identifying AIS and IDE.
  
  
  RESULTS
  HYPOm and CHr detected IDE with comparable sensitivity, 72% versus 69%, but differed in specificity: HYPOm 68% and CHr 53%. For detecting AIS, sensitivity was improved to 85% for HYPOm and 81% for CHr but specificity was reduced for both. Venous Hb had high specificity but poor sensitivity for IDE and AIS. A plasma ferritin level of less than 26.7 μg/L was a good surrogate for assessing IDE.
  
  
  CONCLUSIONS
  RBC indices correlate with AIS and IDE and are more informative than Hb measurement, but lack sufficient sensitivity and specificity to be used as diagnostic tools in blood donors at risk for iron deficiency.
authors.affiliation: The Institute for Transfusion Medicine, Pittsburgh, Pennsylvania; Westat, Rockville, Maryland; Blood Center of Wisconsin, Milwaukee, Wisconsin; Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; Hoxworth Blood Center, University of Cincinnati Academic Health Center, Cincinnati, Ohio; University of California at San Francisco and Blood Systems Research Institute, San Francisco, California; CSL Plasma, Boca Raton, Florida; New England Region, American Red Cross Blood Services, Farmington, Connecticut.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Kiss
authors.forename: Whitney R
authors.initials: WR
authors.lastname: Steele
authors.forename: David J
authors.initials: DJ
authors.lastname: Wright
authors.forename: Alan E
authors.initials: AE
authors.lastname: Mast
authors.forename: Patricia M
authors.initials: PM
authors.lastname: Carey
authors.forename: Edward L
authors.initials: EL
authors.lastname: Murphy
authors.forename: Jerry L
authors.initials: JL
authors.lastname: Gottschall
authors.forename: Toby L
authors.initials: TL
authors.lastname: Simon
authors.forename: Ritchard G
authors.initials: RG
authors.lastname: Cable
mesh_terms: D001782:Blood Donors; D004909:Erythrocyte Indices; D004920:Erythropoiesis; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D000090463:Iron Deficiencies; D007753:Laboratories; D008297:Male; D012372:ROC Curve; D012156:Reticulocytes / Q000166:cytology; D012190:Retroviridae / Q000302:isolation & purification
chemical_list: D006454:Hemoglobins; D005293:Ferritins