hemoglobin A2 in blood

Indications

• evaluation of hemoglobinopathy

Reference interval

1.5-3.5%

Clinical significance

• contribution to total hemoglobin increases with defects in hemoglobin beta-chain (beta-thalassemia)

Increases

• beta thalassemia (trait: 3.7-7%)
• drug-induced megaloblastic anemia
• hemoglobinopathy (values in excess of 10%)
  • hemoglobin C
    • hemoglobin SC (50%)
  • hemoglobin E
  • hemoglobin O

Decreases

• untreated iron deficiency
• erythroleukemia
• hemoglobin H disease
• delta-thalassemia

Specimen

• hemolysate prepared from whole blood (EDTA, heparin, oxalate)
• stable for 30 days at 4 degrees C

More general terms

• hemoglobin subtype in blood

Additional terms

• hemoglobin A2