Hemoglobin A2 levels in healthy persons, sickle cell disease, sickle cell trait, and β-thalassemia by capillary isoelectric focusing

Abstract

Simultaneously measuring major and minor hemoglobin (Hb) variants by capillary isoelective focusing, we obtained HbA2 intervals in healthy volunteers (n = 412) (reference value) and patients with HbS or β- thalassemia. We classified normal HbA2 reference intervals into three age groups: 5 months or younger (1.2% ± 1.5%), 6 months to 1 year (2.2% ± 0.9%), and 1 year or older (2.4% ± 0.9%). These intervals were comparable to those used with other methods. Patients 1 year of age or older with HbS had significantly higher HbA2 levels (sickle cell trait, 2.9% ± 0.9%; sickle cell anemia, 2.8% ± 1.0%; P