Ordering Recommendation

Quantifies HbA2 and HbF in whole blood. Aids in the management of sickle cell disease and in the identification of beta thalassemia carriers.

Mnemonic
HGBA2F COL
Methodology

High Performance Liquid Chromatography (HPLC)

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

Effective August 19, 2013

Age-Definied 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%

No compliance statements are in use for this test.

Note

Recommend quantitation of hemoglobin for definitive diagnosis after 1 year of age.

Hotline History
N/A
CPT Codes

83021

Components
Component Test Code* Component Chart Name LOINC
0050300 Hemoglobin A2 4551-8
0050315 Hemoglobin F 4576-5
0050614 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
  • Hemoglbinopathy (Hb) A2
  • Hemoglobin A2
  • Hemoglobin A2 and F, Blood
  • Hemoglobin F
Hemoglobin (Hb) A[2] and F by Column