Test Details
Methodology
Capillary electrophoresis (CE)
Result Turnaround Time
2 - 5 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Test Includes
Capillary electrophoresis (CE) is performed initially. If an abnormal hemoglobin is detected, appropriate testing will be performed at an additional charge.
Use
Investigate for hemolytic anemia, hemoglobinopathies, and thalassemia
Special Instructions
Specify on the request form the patient's race or ethnic origin (if known) as well as the date of any transfusions administered within the preceding three months.
Limitations
Blood transfusion prior to hemoglobin analysis may cause inconsistent interpretation.
Footnotes
Custom Additional Information
Hemoglobin A2 levels have special application to the diagnosis of β-thalassemia trait, which may be present even though peripheral blood smear is normal. (This reflects the underlying genetic spectrum of β-thalassemia, which in reality is a complex of 20 to 30 distinct conditions.) The microcytosis and other morphologic changes of beta-thalassemia trait must be differentiated from iron deficiency. Low MCV may include the majority of β-thalassemia trait patients but does not differentiate iron deficient individuals. Low Hb A2 levels occur in untreated iron deficiency. If the β-thalassemia is associated with iron deficiency, the Hb A2 level falls, making the differentiation even more difficult (corrected after iron therapy).1 The most definitive evidence for presence of β-thalassemia trait is genetic (family study). Offspring of a person with thalassemia major will have beta-thalassemia trait. Hb A2 may be increased in megaloblastic anemia and may be decreased in sideroblastic anemia, Hb H disease, and erythroleukemia.
Specimen Requirements
Specimen
Whole blood
Volume
1 mL
Minimum Volume
0.5 mL (Note: This volume does not allow for repeat testing.)
Container
Lavender-top (EDTA) tube
Collection Instructions
To avoid delays in turnaround time, please submit a separate lavender-top tube for each test requiring a lavender-top.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Freeze/thaw cycles | Stable x3 |
Reference Range
See table.
Age | Percentage |
|---|---|
<7 m | Not established |
7 m to 1 y | 1.9% to 2.8% |
≥2 y | 1.8% to 3.2% |
Storage Instructions
Refrigerate at 2°C to 8°C.
Patient Preparation
Fasting or fluid restriction is not necessary.
Causes for Rejection
Clotted specimen
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 121060 | Hgb A2, Quant | 121694 | Hgb A2 | % | 4552-6 | |
| 121060 | Hgb A2, Quant | 121676 | Reflex to HPLC | N/A | ||
| Order Code | 121060 | |||||
| Order Code Name | Hgb A2, Quant | |||||
| Order Loinc | ||||||
| Result Code | 121694 | |||||
| Result Code Name | Hgb A2 | |||||
| UofM | % | |||||
| Result LOINC | 4552-6 | |||||
| Order Code | 121060 | |||||
| Order Code Name | Hgb A2, Quant | |||||
| Order Loinc | ||||||
| Result Code | 121676 | |||||
| Result Code Name | Reflex to HPLC | |||||
| UofM | ||||||
| Result LOINC | N/A |
| Order Code | Order Name | Result Code | Result Name | UofM | Result LOINC | |
|---|---|---|---|---|---|---|
| Reflex 1 | 121699 | Hgb A2 by HPLC | 121714 | Hgb A2 | % | 42245-1 |
| Reflex 1 | ||||||
| Order Code | 121699 | |||||
| Order Name | Hgb A2 by HPLC | |||||
| Result Code | 121714 | |||||
| Result Name | Hgb A2 | |||||
| UofM | % | |||||
| Result LOINC | 42245-1 | |||||