title: Hemoglobin A2 levels in healthy persons, sickle cell disease, sickle cell trait, and beta-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 beta-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 < .05). Although reference HbA2 intervals overlapped those in patients with HbS, no overlap in HbA2 levels was noted between these groups and patients with beta-thalassemia (observed range, 4.3% to 7.5%). The higher than normal HbA2 interval in patients with HbS must be considered before a diagnosis of sickle cell trait or sickle cell disease with beta-thalassemia is made.
authors.affiliation: Department of Pathology, Louisiana State University, New Orleans, USA.
authors.forename: R D
authors.initials: RD
authors.lastname: Craver
authors.forename: J G
authors.initials: JG
authors.lastname: Abermanis
authors.forename: R P
authors.initials: RP
authors.lastname: Warrier
authors.forename: D L
authors.initials: DL
authors.lastname: Ode
authors.forename: J M
authors.initials: JM
authors.lastname: Hempe
mesh_terms: D000755:Anemia, Sickle Cell / Q000097:blood*; D002675:Child, Preschool; D006443:Hemoglobin A2 / Q000032:analysis*; D006451:Hemoglobin, Sickle / Q000032:analysis; D006801:Humans; D007223:Infant; D007525:Isoelectric Focusing / Q000379:methods*; D012016:Reference Values; D012805:Sickle Cell Trait / Q000097:blood*; D017086:beta-Thalassemia / Q000097:blood*
chemical_list: D006451:Hemoglobin, Sickle; D006443:Hemoglobin A2