The clinical utility of red blood cells and reticulocyte-related indices for early detection of latent Iron deficiency

Background: Iron deficiency (ID) with and without anemia is common among young women of childbearing age. Screening and early diagnosis of ID before anemia develops are relevant to manage before the symptomatic stage. Several automated red blood cell (RBC) and reticulocyte indices have been investigated to identify early ID. Objectives: To explore the clinical utility of both old (MCV, MCH, and MCHC) and new (Ret-He and IFR) indices for detecting latent ID before the symptomatic anemia stage develops. Methods: A group of female college students at high altitude southern Saudi Arabia was assessed for iron status and associated anemia. Three groups were identified, ID anemia (IDA) group, ID without anemia (i.e., latent ID), and normal group. The lab generated RBC related indices (mean corpuscular volume [MCV], mean corpuscular hemoglobin [MCH], and mean corpuscular hemoglobin concentration), And reticulocyte count and their derived indices (reticulocyte hemoglobin content [RET-He] and immature reticulocyte fraction [IRF]) were collected. The RBC and Reticulocyte indices were compared between the normal, ID and IDA groups in order to identify possible distinguishing parameters of early ID state. Descriptive analysis and significance testing were performed. Results: Ninety-two of two hundred participants (46%) were found to have a latent ID and 30 (15%) had IDA. Hemoglobin, MCV, and MCH showed progressive decrement on their values from the iron replete through iron deplete state to full-blown anemia state. Reticulocytes count and MCV/MCH were significantly lower in the latent ID group compared to the normal group. RET-He and IRF showed no statistical difference between the latent ID and normal groups. Conclusion: Latent ID, before anemia develops, is associated with significant RBC indices, MCV/MCH, changes. These changes can be used to follow-up and detect early recurrence of ID. At our setting of high altitude, Ret-He shows no clinical utility in early diagnosis of ID state. Reticulocyte count drops early before qualitative reticulocyte indices like RET-He, a finding that could be attributed to baseline high-altitude-associated erythrocytosis.