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. 红细胞单细胞光学分析提供了关于细胞血红蛋白浓度及红细胞体积的信息。 我们评价了典型的细胞图血红蛋白浓度/体积分布（Mie Map）在缺铁性贫血（IDA）和地中海贫血特征的识别方面的可靠性，分布曲线由CELL-DYN® Sapphire分析仪（Abbott Diagnostics, Santa Clara, CA, USA）生成。 一共对380例小细胞性贫血进行了研究：220例患有IDA，101例β有地中海贫血特征，30例β有地中海贫血特征合并缺铁性，29 α例地中海贫血特征。 由三名专业人员在没有任何患者病情信息的情况下进行Mie map读图。 读图者作出初步诊断（遗传性或获得性贫血），记录正确分类的百分比。 IDA表现出细胞图较宽发散形状的偏移，而基因携带者在更低的小细胞区域呈现较窄的聚集：100%的IDA被正确分类，96-82%的基因携带者得到确认。 Mie map的目测检查揭示了IDA和地中海贫血特征方面不同的分布；这些模式与数值数据相一致。Mie map有助于大量数据的评估。