Hemoglobin A2 Cut off Values in Egyptian Cohort as a marker of β -Thalassemia carriers

Beta thalassemias (β-thalassemias) are a group of inherited blood disorders caused by reduced or absent synthesis of beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated 1 in 100.000 throughout the world. HbA2 determination plays a key role in screening programs for β-thalassemia since a small increase in this fraction is the most important marker of β-thalassemia heterozygous carriers. This study aims to detect the cut off value of Hb A2 in Egyptian individuals with β-thalassemia and microcytic hypochromic anemia, using automated HPLC. The study was carried out on 112 male and female cases. Their ages ranged from 2 years to 35 years. They were 28 normal cases, 20 cases diagnosed as microcytic hypochromic anemia, 52 cases as β-thalassemia trait and 12 cases as β-thalassemia intermedia. Informed consents were obtained from their care givers. CBC was done to all groups and HbA2 levels were measured using HPLC Bio- Rad D-10 dual program (β-thal short program) for identification of types of Hb and determining the cut off value of Hb A2. The Hb A2 cut off value in microcytic hypochromic anemia cases was >2.2%, in β-thalassemia intermedia cases was >3.2% and in β-thalassemia trait cases was >3.6% which showed the best cut off value, and hence the cut off value of Hb A2 could be used as a factor that plays a key role in screening programs for β- thalassemia carriers.