P1557: DISTINGUISHING OF IRON REFRACTORY IRON DEFICIENCY ANEMIA FROM IRON DEFICIENCY ANEMIA AND THALASSEMIA TRAIT BY SYSMEX RESEARCH RED CELL PARAMETERS

Abstract

Background: Iron refractory iron deficiency anemia (IRIDA), iron deficiency anemia (IDA), and Thalassemia trait (TT) are the most common causes of microcytic anemia. It is possible to discriminate between IDA and TT by routine complete blood count (CBC), hemoglobin (Hb) electrophoresis and iron parameters; however, it is very difficult to distinguish IRIDA from IDA and TT using only routine CBC and iron parameters. Aims: The aim was to distinguish IRIDA from IDA and TT using Sysmex research red cell parameters. Methods: The study included a total of 25 patients (n=10, TT; n=10, true IDA; n= 5, genetically confirmed IRIDA). Traditional [mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), red blood cell count (RBC), and red cell distribution volume (%RDW)] and new red cell parameters [percentage hypochromic RBCs (%Hypo-He); percentage microcytic RBCs (%Micro-R)] were measured in a Sysmex-XN®2000 (Sysmex Corporation, Kobe, Japan), along with iron parameters. Participants’ disorders were categorized based on patients’ ferritin, Hb electrophoresis, genetic results, and CBC values. Results: Compared with the IDA patients, IRIDA patients had significantly higher mean levels of ferritin, RBC, %Hypo-He, %Micro-R and significantly lower mean levels of serum iron level MCV, MCH, and MCHC values (p<0.05 for all). Compared with TT patients, IRIDA patients had significantly higher mean levels of ferritin, %Hypo-He and %RD,W and significantly lower mean levels of serum iron level and MCH values (p<0.05 for all). The RBC, Micro-R, Hypo-He, MCV and MCH cut-off values for discriminating IRIDA from IDA patients were 4.9µL, %60, 50%, 60fL, and 16.0pg, respectively. The RDW, Hypo-He, and MCH cut-off values for discriminating IRIDA from TT patients were %19, %30, and 17.0pg, respectively. Summary/Conclusion: This first study has examined the utility of new red cell parameters in patients with IRIDA. Our findings should be confirmed in larger studies; however, we believe that higher percentage of hypochromic microcytic erythrocytes with an elevated RBC value may be useful predictors for distinguishing IRIDA from IDA patients. As well, a moderate percentage of hypochromic erythrocytes with high RDW value can guide physicians in discriminating IRIDA from TT patients