PB1965 CLINICAL UTILITY OF RETICULOCYTE HEMOGLOBIN EQUIVALENT TO DIFFERENTIATE BETWEEN FUNCTIONAL IRON DEFICIENCY ANEMIA AND TRUE ANEMIA AND DIFFERENT FROM ANEMIA OF OTHER CAUSES OF CHRONIC DISEASE.

Background: Iron Restricted Erythropoiesis can be: 1.Absolute iron deficiency 2. Iron sequestration [impaired iron trafficking] 3. Functional iron deficiency [FID] 4. Heriditary conditions with impaired iron transport & utilization. Anaemia of chronic disease [ACD] is defined as hypoproliferative anaemia of no apparent cause. Ret He is hemoglobin content equivalent of reticulocytes.Monitors iron supply during erythropoiesis over last 2‐3 days, increases within 2‐4 days of iron therapy Aims: To compare Ret He and % Hypo values with standard biochemical markers of iron metabolism: serum iron, TIBC, Transferrin saturation, serum ferritin, sTfR [Soluble Transferrin Receptor] levels and to assess in diagnosing iron deficiency. Methods: [n = 120] analysed [15 M: 10 F ratio,age 10 – 87 yrs] CBC samples [K2 EDTA] analysed on Sysmex XN1000 series.Ret He and Hypo He % identified in the reticulocyte channel by Fluorescence flowcytometry using polymethine dye Patients with Haemoglobin < 10 g/dl tested [1]:Normal patients [n = 25] 20.8 %. [2]: IDA Patients [n = 45] 37.5 %. [3]: CKD Patients on haemodialysis treated with variety of erythropoietin doses [n = 12] 10 %. [4]: CKD Patients [n = 7] 5.8 %. [5]: ACD Patients [n = 31] 25.8 %. Ret‐He: Sensitivity: 97.87 %,Specificity: 96.15 %,PPV: 98.92 %,NPV: 92.59 % Results: 20 % Normal patients Ret He 33 pg In 5% of ACD,IDA co‐existented so differentiate ACD and ACD/IDA as iron supplementation is beneficial for ACD/IDA patients but deleterious for ACD patients. 37 % IDA Patients Ret He was < 23.6 pg. 3.3 %patients of thalassemia with IDA, Ret‐He: 19.5pg. STfR elevated in IDA cases, but was normal in ACD &FID cases Hypo He % in FID [> 5%],IDA [>10%] ACD [<5 %]. Hypo He % measure is time average marker of iron restricted erythropoiesis [20‐120 days]. 10% CKD patients on erythropoietin doses Ret‐He < 25.5 pg presents FID Normal Range for Ret He: 31‐35 pg.Summary/Conclusion: Serum Iron, TIBC, % T Sat. Screens anemia but Ret He detects & gives expended information at cellular levels so assess true status of iron and predictor of marrow iron storesDetects IDA, FID, ACD which helps differential diagnosis Ret He < 23.6 pg. suggest classical iron deficiency & also predicts FID in those receiving ESA [erythropoietin stimulating agent] therapy. Indicates a non responder to rHuEPO/ ESA or FID