An elevated level of hemoglobin A2 is used as a screening test for beta-thalassemia trait. Megaloblastic anemia can result in a false-positive screening test.
Patient selection: megaloblastic anemia
Megaloblastic anemia results in an increase in hemoglobin A2.
Clinical features:
(1) megaloblastic anemia
(2) elevated level of hemoglobin A2 consistent with beta-thalassemia
(3) return of the hemoglobin A2 to normal after treatment of the megaloblastic anemia
Usually, the MCV and RDW are clues to thalassemia, but in megaloblastic anemia these changes would be masked. However, the presence of a low MCV and RDW would be an indication of true beta-thalassemia trait.
To read more or access our algorithms and calculators, please log in or register.
