Clinical Value of Hypochromia Markers in the Detection of Latent Iron Deficiency in Nonanemic Premenopausal Women.

Abstract

Iron deficiency (ID) is the most common cause of anemia in fertile women and hemoglobin (Hb) within the reference interval does not exclude ID. The consequence of an imbalance between the iron requirements and supply is a reduction of red-cell Hb content, which causes hypochromic cells. The aim of this study was to assess the reliability of new parameters low Hb density (LHD%), reticulocyte Hb equivalent (RetHe), and percentage of hypochromic erythrocytes (%HypoHe) in the detection of latent ID (LID), defined as depletion of iron stores without anemia. Two hundred fifty consecutive nonanemic women in fertile age (18-40 years, mean 33.5 years), whose analyses had been requested by general practitioners, were included. Independent samples t-test, receiver operating characteristic (ROC) curve analysis (gold standard for detecting LID ferritin <30 μg/l), and Cohen's kappa index were applied. One hundred fifty-three women had ferritin within the reference range and Hb >120 g/L; 97 (38.8%) had LID. The results were as follows: %HypoHe-AUC 0.934, cutoff 1.6%, sensitivity 85.7%, specificity 92.1%; RetHe-AUC 0.914, cutoff 29.9 pg, sensitivity 86.8%, specificity 85.7%; LHD%-AUC 0.898, cutoff 5.0%, sensitivity 85.9%, specificity 84.1%. Applying those cutoffs, agreement between ferritin and %HypoHe was κ 0.61 and 0.56 for RetHe and LHD%. LHD%, %HypoHe, and RetHe emerge as reliable tests for the investigation of LID and could improve the ability to detect ID before anemia is present.