POS-261 ROLE OF RETICULOCYTE HAEMOGLOBIN EQUIVALENT(RET HE) IN ASSESSING IRON DEFICIENCY ANAEMIA (IDA) AND FUNCTIONAL IRON DEFICIENCY(FID) IN PATIENTS OF CHRONIC KIDNEY DISEASE

Abstract

Anemia is most commonly associated feature in patients of CKD. Knowledge about the status of the iron stores, circulating iron and erythropoietin levels are important to diagnose the cause and treat anemia in patients of CKD. Ferritin is an acute phase reactant and can be falsely raised in patients of CKD. Similarly, transferrin may be falsely decreased, TIBC and TSAT may be falsely normal because of chronic disease. Hence, they cannot be relied upon. To find out the exact status of iron stores in the body and the cause of anemia in CKD, patients have to undergo investigations including iron studies, serum EPO, hepcidin levels and bone marrow perl’s staining which is quite expensive and is not routinely available IDA is diagnosed by low iron and normal EPO. FID is characterized by normal iron and EPO. Whereas EPO deficiency is characterized by normal iron and decreased EPO. This study was carried out to correlate the levels of novel marker Ret HE, serum iron profile with iron reserves. In addition, we looked at the efficacy of Ret HE in determining the cause of anemia and its utility in differentiating IDA/FID from anaemia due to EPO deficiency in patients of CKD. Ret HE is widely available, cheap and cost-effective investigation. Prospective, observational study, total of 66 patients were included. All adults diagnosed as CKD and having anaemia were included in the study. Patients were excluded if they denied consent, were diagnosed with hemoglobinopathies, hematological malignancies, hemolytic anemias, or if they had received IV iron therapy within last 6 months. Demographic data, history, physical examination, the type of management was noted and the data compiled. Bone marrow iron stores was taken as the gold standard to diagnose iron deficiency. Bone marrow iron stores was compared to the biochemical iron profile and Ret HE and the comparison between the three was made. Total of 76 (39M and 37F) patients with CKD and anaemia were included. In 10 patients bone marrow was not available hence were excluded in analysis. Out of 66 patients 15 patients had IDA, 19 had EPO deficiency and 35 had FID. Three patients had both IDA and EPO deficiency. Sensitivity and specificity of the parameters is summarized below. Ret HE was most sensitive (85.7%) for diagnosing IDA at a cut off of 27.2pg. Serum ferritin was most specific (87%) for diagnosing IDA at a cut off value of 100mcg/dl. The sensitivity and specificity of RetHE for diagnosing anaemia due to decreased available iron (IDA/FID) was highest i.e. 80% and 50% respectively at a cut off value of 27.2pg. The study results suggest low sensitivity and specificity of serum iron and TSAT in diagnosing IDA and FID and low sensitivity of serum ferritin in diagnosis IDA2. RetHE is the most sensitive marker for diagnosing both iron deficiency and functional iron deficiency is patients of CKD. 3. As RetHe cannot differentiate between IDA and FID so it should be used along with serum ferritin to diagnose the cause of anaemia in CKD patients. 4. We suggest the following to diagnose the cause of anaemia in CKD Ret HE FerritinIDA <27.2 pg <100mcg/dlFID <27.2pg >100mcg/dlEPO deficiency >27.2pg >100mcg/dl 5. Ret HE is cheap and cost-effective investigation in low income countries to diagnose iron deficiency