Ordering Recommendation

Use to quantify HbA2 and HbF in whole blood. Aids in the management of sickle cell disease and in the identification of β thalassemia carriers.

Mnemonic
HB A2F COL
Methodology

High Performance Liquid Chromatography/Electrophoresis

Performed

Sun-Sat

Reported

1-4 days

New York DOH Approval Status
This test is New York DOH approved.
Specimen Required
Patient Preparation
Collect

Lavender (EDTA) or pink (K2EDTA).

Specimen Preparation

Transport 5 mL whole blood. (Min: 0.2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Frozen or room temperature specimens.

Remarks
Stability

Ambient: Unacceptable; Refrigerated: 1 week; Frozen: Unacceptable

Reference Interval

Age-Defined Normal Hemoglobin Reference Intervals

Age
Hb A2 Percent
Hb F Percent
0-1 month 0.0-1.4 45.8-91.7
2 months 0.0-2.0 32.7-85.2
3 months 0.1-2.6 14.5-73.7
4 months 0.8-3.0 4.2-56.9
5 months 1.5-3.3 1.0-38.1
6-8 months 1.8-3.5 0.9-19.4
9-12 months 1.9-3.5 0.6-11.6
13-23 months 1.9-3.5 0.0-8.5
2 years and older 2.0-3.5 0.0-2.1

Interpretive Data

In laboratory testing to confirm a diagnosis of a β-thalassemia trait diagnosis, Hb A2 levels should be considered in conjunction with family history and additional laboratory data, including serum iron and iron binding capacity, red cell morphology, hemoglobin, hematocrit, and mean corpuscular volume (MCV).

Patients with a combination of iron deficiency and β-thalassemia may have a normal A2 level. In these cases, elevated A2 level cannot be used to screen for β-thalassemia in these cases.


Patient State Hb A2 Level Hb F Level
Heterozygous β-thalassemia 4-9% 1-5%
Homozygous β-thalassemia Normal or Increased 80-100%
Heterozygous HPFH Less than 1.5% 10-20%
Homozygous HPFH Absent 100%

Compliance Category

FDA

Note

Recommend quantitation of hemoglobin for definitive diagnosis after 1 year of age. If abnormal peaks suggestive of a hemoglobin variant are detected, then Capillary Electrophoresis will be added to aid in confirmation and identification of the variant. Additional charges apply

Hotline History
N/A
CPT Codes

83021; if reflexed, add 83020

Components
Component Test Code* Component Chart Name LOINC
2008793 Hemoglobin, Capillary Electrophoresis 13514-5
3002709 Hemoglobin A2 4551-8
3002710 Hemoglobin F 4576-5
3002711 Hemoglobin A2 and F Interpretation 21026-0
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • A2 Hemoglobin
  • F-Hemoglobin
  • Hemoglobin A2
  • Hemoglobin A2 and F, Blood
  • Hemoglobin F
  • Hemoglobinopathy (Hb) A2
Hemoglobin (Hb) A2 and F by Column with Reflex to Electrophoresis