Laboratory variables for assessing iron deficiency in REDS-II Iron Status Evaluation (RISE) blood donors - eScholarship

NIH Public Access Author Manuscript Transfusion. Author manuscript; available in PMC 2014 November 01. NIH-PA Author Manuscript Published in final edited form as: Transfusion. 2013 November ; 53(11): 2766–2775. doi:10.1111/trf.12209. Laboratory variables for assessing iron deficiency in REDS-II Iron Status Evaluation (RISE) blood donors Joseph E. Kiss, Whitney R. Steele, David J. Wright, Alan E. Mast, Patricia M. Carey, Edward L. Murphy, Jerry L. Gottschall, Toby L. Simon, Ritchard G. Cable, and for the NHLBI Retrovirus Epidemiology Donor Study-II (REDS-II) The Institute for Transfusion Medicine, Pittsburgh, Pennsylvania; Westat, Rockville, Maryland; the Blood Center of Wisconsin, Milwaukee, Wisconsin; the Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin; the Hoxworth Blood Center, University of Cincinnati Academic Health Center, Cincinnati, Ohio; the University of California at San Francisco and Blood Systems Research Institute, San Francisco, California; CSL Plasma, Boca Raton, Florida; and New England Region, American Red Cross Blood Services, Farmington, Connecticut. NIH-PA Author Manuscript 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. STUDY DESIGN AND 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 µ.g/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. NIH-PA Author Manuscript 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 u.g/L was a good surrogate for assessing IDE. CONCLUSION—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. Iron deficiency is a frequent condition that arises as a direct consequence of regular blood donation in both men and women, who lose approximately 230 mg of elemental iron with each whole blood donation. This amount represents approximately 25% of the average iron Address correspondence to: Joseph E. Kiss, MD, Hemapheresis and Blood Services, The Institute for Transfusion Medicine, University of Pittsburgh, 3636 Boulevard of the Allies, Pittsburgh, PA 15213; JKiss@itxm.org. CONFLICT OF INTEREST AEM has received payment for educational lectures from Siemens Corporation. The other authors declare that they have no conflicts of interest relevant to the manuscript.