title: Ret-Y a measure of reticulocyte size: a sensitive indicator of iron deficiency anemia.
abstract: In this study the size of reticulocytes was measured, reticulocyte-Y (Ret-Y), to distinguish iron deficiency anemia from the anemia of chronic disease using a Sysmex XE2100 cell counter. We evaluated this parameter prospectively in 100 patients seen for the evaluation of anemia. A clinical diagnosis of iron deficiency anemia or anemia of chronic disease was made on the basis of a complete blood count, examination of the peripheral smear, and serum ferritin along with a history and physical examination. We analyzed the sensitivity and specificity of the Ret-Y in relationship to the clinical diagnosis. We also measured serum transferrin receptor levels to use as the gold standard laboratory test for iron deficiency against which we compared the Ret-Y. In 40 normal individuals with normal serum ferritin and transferrin receptor levels the mean Ret-Y was 1874 +/- 178 (1 SD). The mean Ret-Y in the anemia of chronic disease group (n=62) was 1722 +/- 162, not significantly different from normal. The mean Ret-Y value among iron-deficient patients (n=38), was 1407 +/- 136 (P <0.01 vs. the anemia of chronic disease group's Ret-Y value). Receiver operator curves showed that Ret-Y correlated closely to the serum transferrin receptor and was superior to the mean corpuscular volume, and ferritin level, in differentiating the type of anemia. The Ret-Y parameter has the highest overall sensitivity and specificity of the panel of tests routinely used in differentiating iron deficiency anemia from anemia of chronic disease.
authors.affiliation: Department of Pathology, Johns Hopkins, University School of Medicine, Baltimore, MD 21231, USA. tkickler@jhmi.edu
authors.forename: T S
authors.initials: TS
authors.lastname: Kickler
authors.forename: M J
authors.initials: MJ
authors.lastname: Borowitz
authors.forename: R E
authors.initials: RE
authors.lastname: Thompson
authors.forename: N
authors.initials: N
authors.lastname: Charintranont
authors.forename: R
authors.initials: R
authors.lastname: Law
mesh_terms: D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000473:pathology*; D048429:Cell Size; D005293:Ferritins / Q000097:blood; D006801:Humans; D011990:Receptors, Transferrin / Q000097:blood; D012156:Reticulocytes / Q000473:pathology*
chemical_list: D011990:Receptors, Transferrin; D005293:Ferritins