Evaluation of the Discrimination between Beta-Thalassemia Trait and Iron Deficiency Anemia Using Different Indexes

Background: Iron deficiency anemia (IDA) and beta-thalassemia trait (BTT) are the most common types of microcytic hypochromic anemias. The aim of this study was to evaluate the reliability of different RBC indices for discrimination between IDA and BTT in Sudanese patients. Methods and Results: This cross-sectional laboratory-based study was conducted among 200 patients (100 patients suffering from BTT and 100 from IDA) who attended the public health hospitals of Khartoum State (Sudan), from Jan 2021 to Feb 2022. The diagnosis of BTT was based on CBC and hemoglobin electrophoresis, and was confirmed by PCR. The diagnosis of IDA was based on complete blood count, reduced serum iron levels, and ferritin levels. Pregnant women, patients who had received a blood transfusion within three months of the study, and patients with thalassemia coexisting with IDA or other hemoglobinopathies were excluded from the study. A series of red blood cell indices were analyzed to differentiate IDA and BTT. The sensitivity, specificity, positive predictive value, negative predictive value, and Youden index (J) were calculated for each index. In BTT and IDA patients, mean values of Hb, hematocrit, and mean corpuscular volume were 10.9g/dL, 33.96%, 59.11fL, and 8.5g/dL, 26%, 68fL, respectively. All RBC indices were decreased in BTT and IDA. Mean RBC count was increased in BTT while showing normal values in IDA. In BTT patients, hemoglobin electrophoresis showed high HbA2 (6.4%) and HbF (1.95%) but a decreased HbA (78.2%). Conclusion: The best discrimination index according to J was Mentzer index (0.85), followed by Sidrah index (0.83), Ehsani index (0.81), RBC count (0.80), RDWI (0.79), Green and King index (0.76), MDHL (o.76), Srivastava index (o.76), and England and Fraser index (0.7). The lowest J was presented in Ricerca index (0.45), Shine and Lal index (0.01), and MCHD (0).