Red Cell Cytogram in CELL-DYN^® Sapphire: A Ready-to-Use Function for Recognizing Thalassemia Trait

Single-cell optical analysis of red blood cells provides information on the cellular hemoglobin concentration and volume of red cells. We evaluated the reliability of the typical profiles of the cytogram hemoglobin concentration/ volume (Mie Map), produced by the CELL-DYN^® Sapphire analyzer (Abbott Diagnostics, Santa Clara, CA, USA) in the discrimination of iron deficiency anemia (IDA) and thalassemia trait. A total of 380 patients with microcytic anemia were studied: 220 with IDA, 101 β-thalassemia trait, 30 β-thalassemia trait with concomitant iron deficiency, 29 α-thalassemia trait. Three professionals reviewed the Mie maps, with no information regarding the disease of the patient. The observers made a presumptive diagnosis (genetic or acquired anemia) and the percentages of correct classifications were recorded. IDA showed broad shaped shift of the cytogram while carriers presented narrow clustering in the lower microcytic area: 100 % IDA were correctly classified and 96–82% of carriers were recognized. Visual inspection of the Mie map reveals different profiles in IDA and thalassemia trait; those patterns are in concordance with the numerical data Mie map helps in the evaluation of large amounts of data.