Usefulness of Reticulocyte Haemoglobin Equivalent in the Evaluation of Iron Deficiency Status: A Cross-sectional Study

Introduction: Iron deficiency is the most frequent cause of nutritional anaemia. Evaluation of parameters like serum ferritin and iron is critically important for evaluation of the iron status of patients and diagnosis of Iron Deficiency Anaemia (IDA). But in inflammatory disorders, ferritin concentration may be normal or increased due to the acute phase response, resulting in inaccurate interpretation of the iron status. Similarly, the serum Iron levels may be high in cases of thalassaemia with combined iron deficiency. Reticulocyte Haemoglobin equivalent (RET-He) which correlates to the iron content in reticulocytes is effective, convenient and provides useful information for the immediate diagnosis and treatment of iron deficient states. Aim: The aim of this study was to evaluate the diagnostic performance of RET-He level by comparing it with the iron status of the patients. Materials and Methods: This cross-sectional study was done in Department of Pathology at Tagore Medical College and Hospital, Chennai, Tamil Nadu, India, from December 2020 to November 2021. The complete blood count, RET-He, serum iron and serum ferritin levels of 406 patients with microcytic hypochromic anaemia and dimorphic anaemia were reviewed and RET-He levels were compared with the serum iron and ferritin levels. The p-value was calculated using Statistical Package for Social Sciences (SPSS) IBM software version 28.0. The sensitivity of RET-He and serum ferritin levels in evaluating iron deficiency were calculated. Results: Low RET-He was observed in 394 cases, low serum iron in 401 cases and reduced serum ferritin in 376 cases. Twenty one of 34 cases of IDA with concomitant inflammation showed low RET-He and serum iron, despite normal to high serum ferritin levels. Five cases of iron deficiency with concomitant Haemoglobin defect also showed low RET-He levels and serum ferritin, whereas the serum iron was raised. Low RET-He was observed in 17 cases of dual deficiency anaemia i.e., iron deficiency along with vitamin B12/folate deficiency. Conclusion: It was concluded that measurement of the reticulocyte haemoglobin content provides useful information for the diagnosis, treatment and monitoring of iron deficient states.