Use of Serum Iron Status and Hemoglobin A2 Levels for Discrimination Between Iron Deficiency and Thalassemia Minor

Abstract

We read with interest the article by Nalbantoglu et al. [1]. In their article, it was stated that the valid formulas calculated from erythrocyte indices on automated blood counts are not sufficient to discriminate between thalassemia minor (TM) and iron deficiency (ID) in pediatric patients. It is also reported that the most reliable discrimination between these two entities might be done using the parameters of body iron status (serum iron↓, serum iron binding capacity↑, and serum ferritin↓) and hemoglobin A2 (HbA2↑) level. These tests, if available, were suggested for achieving a definite diagnosis in every case with microcytosis. Based on our experience [2-6], we do agree with the authors' opinion regarding the incapability of the formulas to discriminate between these two entities. However, we would like to emphasize that the parameters suggested by the authors might also prove insufficient in some particular situations. With this letter, we want to point out those particular clinical conditions. These conditions should be taken into consideration in discriminating between TM and ID. NORMAL A2 BETA-THALASSEMIAIn these patients without an altered HbA2 level, thalassemia may be overlooked [7]. However, normal body iron status in the patient with microcytosis should alert the clinician to the presence of thalassemia, and the next step should be parental study. Presence of a similar situation in at least one parent would indicate thalassemia. DELTA-BETA-THALASSEMIAPatients with delta-beta-thalassemia have normal body iron status and low HbA2 levels [7]. In addition, red cell distribution width (RDW) value is abnormally wide [2], suggesting the possibility of ID. Family studies are necessary. Presence of similar results in at least one parent would indicate delta-beta-thalassemia.