Identifying the Lower Limit of Haemoglobin A2 in Individuals with Beta Thalassemia Trait

Objective: To determine the sensitivity, specificity and diagnostic accuracy of High Performance Liquid Chromatography in the detection of β-thalassemia trait. To determine the lower cut-off limit of HbA2 in the detection of β-thalassemia trait by using High Performance Liquid Chromatography. Study Design: Validation study. Place and Duration of Study: Department of Haematology, Armed Forces Institute of Pathology, Rawalpindi Pakistan, from Aug 2021 to Mar 2022. Methodology: A total of 243 patients with suspected β-thalassemia were included in this study. Inclusion criteria included patients with a mean corpuscular volume of less than 75 fl and a mean corpuscular haemoglobin of less than 25 pg. Those patients who had received blood transfusions within the past three months, had any other haemoglobinopathy, abnormal iron studies or β-thalassemia major were excluded. Blood samples were obtained from all patients which were tested for the presence of HbA2 using High Performance Liquid Chromatography and genetic mutation of beta globin chain was confirmed by PCR methods. Data was analyzed by SPSS 26.0. Results: Our patients had a mean age of 25.57±13.12 years with a female majority: 132(54.3%). A total of 132(54.3%) patients tested positive for β-thalassemia trait with a cut-off of 4.0% using HPLC, while 130(53.5%) tested positive for beta globin gene mutation using PCR. High Performance Liquid Chromatography was found to have a sensitivity of 96.2%, a specificity of 93.8% and a diagnostic accuracy of 95.1% with a cut-off of 4.0%. ..... Conclusion: High Performance Liquid Chromatography is an excellent modality for the....