Details

Hemoglobinopathy Evaluation

hemoglobin electrophoresis , Antrim #21245, EPIC: LAB5862, SOFT: HGEVL

Instructions

A Complete Blood Count (CBC) is required to perform a Hemoglobinopathy Evaluation. Therefore, if a CBC has not been performed within the last 30 days, a CBC will be ordered.

Specimen Collection Criteria

Collect: One Lavender-top EDTA tube for Hemoglobinopathy Evaluation AND one Lavender-top EDTA tube for Complete Blood Count. (Minimum Whole Blood: 1.0 mL each tube.)

NOTE: The second Lavender-top EDTA tube is not required if a Complete Blood Count (CBC) or CBC with Differential (CBCD) is ordered and drawn at the same time, or has been performed in the last 30 days. If there is not a separate order for a CBC, and CBC will be ordered.

Physician Office/Drawsite Specimen Preparation

Do not centrifuge. Do not freeze. Store whole blood refrigerated (2-8°C or 36-46°F) prior to transport. (Minimum Whole Blood: 1.0 mL each tube.)

Preparation for Courier Transport

Transport: Whole blood specimen or packed cells, refrigerated (2-8°C or 36-46°F). (Minimum Whole Blood: 1.0 mL each tube.)

Rejection Criteria

  • Frozen specimens.
  • Centrifuged specimens.
  • Severely hemolyzed specimens.

Storage

Specimens stored as whole blood or packed cells at 2oC to 8oC are stable for 28 days.

Performed

Sunday – Saturday (day shift only). 
Confirmation of Hemoglobin variant by electrophoresis performed on Thursday.
Results available in 3–5 business days.

Reference Range

Hemoglobin Age Reference Range (%)
Hb A2 Less than 12 months
1 year - Adult
0.0-3.3
2.0-3.3
HbF 0-30 days
31 days - 23 months
2 years - Adult
60-90
Less than or equal to 60
0.0-2.0
HbA 0-30 days
31 days - 24 months 
2 years - Adult
10-40
40-98.5
94.5-98.5

Test Methodology

Electrophoresis and High Performance Liquid Chromatography (HPLC).

The lab protocol consists of automatic chromatographic analysis (HPLC) to quantitate Hgb A2, fetal hemoglobin and Hgb A. If an abnormal hemoglobin is identified by chromatography, electrophoresis (alkaline and/or acid gel) will be performed to confirm the identity of the variant hemoglobin. If an abnormal hemoglobin is not identified, electrophoresis will not be performed routinely.

Interpretation

The final interpretation is made by a pathologist.

Our current methods allow for detection of a number of hemoglobins including Hemoglobin S, C, D, E, Hasharon, Lepore, some A2 variants and usually G Philadelphia. It can also be determined whether an individual is heterozygous or homozygous for the hemoglobin variant. Because of the great number of hemoglobin variants, the Beaumont Laboratory is unable to identify all possible variants and in some cases the blood sample or an additional sample is sent to Mayo Medical Laboratories. Based on hemoglobin A2 and F levels and CBC results, diagnoses of ß (beta) or delta-ß (delta-beta) thalassemia (hetero or homozygous) can be made.

Hbg A2 is elevated in ß thalassemia trait, although if a patient has co-existing iron deficiency, the Hgb A2 level may be normal. Hgb A2 levels are also elevated in sickle cell trait, sickle cell disease, megaloblastic anemia and hyperthyroidism. Only ß thalassemia (hetero or homozygous) would be associated with thalassemic CBC indices (low MCV, high or high-normal RBC). Hgb A2 levels are low or low-normal in alpha thalassemia, delta thalassemia, iron deficiency and sideroblastic anemia.

Hgb F levels are much higher in the neonate than an older child or adult. Hgb F may be slightly increased in ß thalassemia trait and moderately increased in delta-beta thalassemia. It is also increased in hereditary persistence of fetal hemoglobin, a condition most commonly seen in African-Americans. Slight increases may also be acquired and can occur with several bone marrow abnormalities (e.g., leukemias, aplastic anemia), severe anemias and in pregnancy.

Clinical Utility

Hemoglobin electrophoresis is usually ordered for detection of abnormal hemoglobins, ß thalassemia, and hereditary persistence of fetal hemoglobin (HPFH). It cannot be used to detect alpha thalassemia trait in individuals over a few weeks of age.

CPT Code

83021. If reflexed, add 83020.

Test Codes

Antrim #21245, EPIC: LAB5862, SOFT: HGEVL

Last Updated

7/11/2019