High Performance Liquid Chromatography as A Gold Standard Versus Mentzer Index for Screening Beta-Thalassemia Trait: Diagnostic Correlation and Efficacy

INTRODUCTION: Beta-thalassaemia is a hereditary blood disorder characterized by a partial (β⁺) or complete (β⁰) reduction in the synthesis of beta-globin chains of hemoglobin. The heterozygous state of either mutation results in the beta-thalassaemia trait, in which the hallmark finding is an elevated level of Hemoglobin A₂ (HbA₂), composed of α₂δ₂ chains. Accurate detection of this condition is vital for recessive gene testing and prevention programs. However, high-performance liquid chromatography (HPLC) has emerged as the recommended method due to its accuracy, reproducibility, and ease of use, though it is currently limited to few laboratories in the country. MATERIALS AND METHODOLOGY: This cross-sectional study evaluated individuals with microcytic, hypochromic anemia, in whom beta-thalassaemia trait was suspected based on red blood cell indices. A complete blood count (CBC) was performed using an automated hematology analyzer, and the Mentzer Index (MCV/RBC) was calculated for each subject. Hemoglobin analysis was performed using the VARIANT™ system (Bio-Rad Laboratories), a fully automated HPLC platform utilizing the Beta-Thal Short Program. RESULTS: HPLC proved to be a rapid, technically straightforward, and highly reproducible method for the quantification of HbA₂. Among individuals confirmed as carriers of classical beta-thalassaemia, the HbA₂ level was consistently elevated above 4.0%, with values ranging from 4.5% to 8.1%, and a mean value of 5.9%. These individuals also demonstrated microcytosis and hypochromia, with mean corpuscular volume (MCV) < 75 fL and mean corpuscular hemoglobin (MCH) < 27 pg. MI values < 13 suggested β-thalassaemia trait, while values > 13 were more consistent with iron deficiency anemia. CONCLUSION: High-performance liquid chromatography (HPLC) is a reliable and efficient confirmatory method for the identification of beta-thalassaemia trait, with an HbA₂ cut-off level > 4.0% being predictive of carrier status. When combined with red cell indices—particularly MCV and MCH—and screening tools such as the Mentzer Index, HPLC offers a robust strategy for the preliminary identification of beta-thalassaemia carriers. This approach facilitates early genetic counseling and guides the need for molecular studies where necessary. Integration of these parameters provides a cost-effective and efficient diagnostic pathway, particularly valuable in regions where molecular testing is limited.