A-169 Mean reticulocyte volume reported by Mindray 6800 Plus for the diagnosis of iron restricted erythropoiesis

Abstract Background The Mindray BC 6800+ counter, using a new software version, can report mean reticulocyte volume (MRV); we study its values in anemia of different underlying causes and the reliability for the diagnosis of iron deficient erythropoiesis. Methods 606 samples collected in K2EDTA anti-coagulant were analyzed. The scope of the pathology included a variety of diseases representative of the daily workload: 105 healthy subjects, 55 non-anemic patients, 202 microcytic anemia (including thalassemia carriers and iron deficiency anemia), 215 normocytic anemia (hematology malignancies and anemia of chronic disease) , 84 macrocytic anemia (lack of vitamin B12 or folate and myelodysplasic syndromes (MDS). C reactive protein (CRP), S-iron, transferrin saturation,s- ferritin and soluble transferrin receptor (sTfR) were assayed assayed in a analyzer Cobas c 502 (Roche Diagnostics) analyzer . Kolmogorov-Smirnoff was used to verify normal distribution of data. Differences among groups were assessed using analysis of variance, considering P < 0.05 to be significant. For post hoc comparisons of outcomes between each pair of groups Scheffé correction was applied. Receiver operating characteristic analysis was used to assess the diagnostic performance of MRV for detecting iron deficient erythropoiesis. Gold standard for iron deficiency was sTfR >52 nmol/L. Results Gaussian distribution was proven. Whole MRV range 51.8-151.3 fL Mean and range in healthy subjects 107.8 fL, 94.6-121.2 fL Microcytic anemia mean 78.5 fL standard deviation (SD) 13.5 fL Normocytic anemia Mean 105.1 fL, SD 16.9 fL Macrocytic anemia Mean 122.5 fL, SD 18.6 fL In the microcytic group, the values in patients with IDA (MRV mean 78.8 fL, SD 14.3 fL) and thalassemia carries (MRV mean 76.6 fL, SD 10.2 fL) were not significantly different P=0.0756. So patients with restricted erythropoiesis, due to lack of iron or globin, had similar low values. Values over the reference range in the macrocytic group is not related to iron status, reflects the megaloblastosis. Based on Hemoglobin (Hb), Mean cell volume (MCV) , CRP, ferritin and sTfR values the patients were classified as , iron deficiency (IDA ), anemia of chronic disease (ACD) under therapy, and mixed anemia (ACD with iron deficiency, ACD/IDA) , or latent iron deficiency (LID). MVR values were: IDA 78.8 fL , SD 14.3 fL; ACD /IDA 90.5 fL , SD 17.8 fL; ACD 97.7 fL , SD 18.8 fL LID 88.4 fL , SD 16.9 fL. The groups had MRV values significantly different P=0.0001, except the healthy group and ACD with adequate iron supply patients, P=0.0754, IDA and LID groups P=0.0809. Using a cut off MRV 94.6 fL, iron deficient erythropoiesis could be diagnosed sensitivity 82.9%, specificity 97.6%. Area under the curve was 0.929 (95% CI 0.889–0.949) Conclusions Disturbances in erythropoiesis and iron metabolism may occur in many patients, the challenge is to identify these patients as early as possible. MRV provides a sensitive method for quantifying the haemoglobinization of reticulocytes. It is a reliable marker to identify iron deficient erythropoiesis, MRV may allow the complete scope of disorders of iron metabolism to be identified quickly and managed.