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Epic Code LAB1230806 Hemoglobin Electrophoresis Evaluation, Blood

Important Note

LAB ONLY ORDERABLE

Additional Codes

Mayo code: HBEL1

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Useful For

Diagnosis and classification of hemoglobin disorders, including thalassemias and hemoglobin variants

Specimen Type

Whole Blood EDTA


Necessary Information


Include recent transfusion information.

 

Include most recent complete blood cell count results.

 

Metabolic Hematology Patient Information (T810) is strongly recommended. Testing may proceed without this information, however if the information requested is received, any pertinent reported clinical features and data will drive the focus of the evaluation and be considered in the interpretation.

 

The laboratory has extensive experience in hemoglobin variant identification and many cases can be confidently classified without molecular testing. However, molecular confirmation is always available, subject to sufficient sample quantity (eg, multiplex ligation-dependent probe amplification testing requires at least 2 mL of sample in addition to protein testing requirements). If no molecular testing or specific molecular tests are desired, utilize the appropriate check boxes on the form. If the form or other communication is not received, the reviewing hematopathologist will select appropriate tests to sufficiently explain the protein findings which may or may not include molecular testing.



Specimen Required


Container/Tube:

Preferred: Lavender top (EDTA)

Acceptable: Yellow top (ACD solution B), green top (sodium heparin)

Specimen Volume: 10 mL

Collection Instructions: Send whole blood specimen in original tube. Do not aliquot.


Specimen Minimum Volume

1 mL (this volume will limit reflex testing possibilities)
3 mL if multiplex ligation-dependent probe amplification is needed

Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available in Special Instructions:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing-Spanish (T826)

2. Metabolic Hematology Patient Information (T810) in Special Instructions

3. If not ordering electronically, complete, print, and send a Benign Hematology Test Request (T755) with the specimen

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole Blood EDTA Refrigerated 7 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Cautions

Some hemoglobin disorders and variants are not detected by the screening methods including common alpha-thalassemia conditions and require further reflex testing to identify. If a family history of a known hemoglobin disorder, prior therapy for a hemoglobin disorder, or otherwise unexplained lifelong/familial symptoms such as hemolysis, microcytosis, erythrocytosis/polycythemia, cyanosis, or hypoxia are present, this should be clearly communicated to the laboratory so appropriate reflex testing can be added, see Metabolic Hematology Patient Information (T810).

 

Recent transfusion may mask protein results including hemoglobin electrophoresis, hereditary persistence of hemoglobin F (HPFH) by flow cytometry, stability studies, and sickle solubility studies depending on percentage of transfused cells present.

 

Some hemoglobin variants can originate from the donor blood product and not from the tested recipient. These are typically found in low percentage.

 

If the patient has undergone a bone marrow transplant, the results may show atypical results and should be interpreted in the context of clinical information.

 

Some therapies cause artefactual effects in protein studies, including hydroxyurea and decitabine (increased HbF levels), Voxelotor (artefactual peaks) and gene therapy (alternate protein detection, beta T87Q, by mass spectrometry). Clear communication of prior therapy is strongly recommended.

Clinical Information

A large number of variants of hemoglobin (Hb) have been recognized. Although many do not result in clinical or hematologic effects, clinical symptoms that can be associated with Hb disorders include microcytosis, sickling disorders, hemolysis, erythrocytosis/polycythemia, cyanosis/hypoxia, anemia (chronic, compensated or episodic), and increased methemoglobin or sulfhemoglobin results (M-hemoglobins).

 

For many common Hb variants (eg, HbS, HbC, HbD and HbE, among many others), protein studies will be sufficient for definitive identification. However, some Hb conditions may be difficult to identify by protein methods alone and may require molecular methods for confirmation. Hb disorders commonly occur as compound disorders (2 or more genetic variants) that can have complex interactions and variable phenotypes. In these situations molecular testing may be necessary for accurate classification. It is important to note that although powerful as an adjunct for a complete and accurate diagnosis, molecular methods without protein data can give incomplete and possibly misleading information due to limitations of the methods. Accurate classification of hemoglobin disorders and interpretation of genetic data requires the incorporation of protein analysis results. This profile is well-suited for the classification of hemoglobin disorders.

 

Mayo Clinic Laboratories receives specimens from a wide geographic area and nearly one-half of all specimens tested exhibit abnormalities. The most common abnormality is an increase in HbA2 to about 4% to 8%, which indicates beta-thalassemia minor when present in the correct clinical context. A wide variety of other hemoglobinopathies are also frequently encountered. Ranked in order of relative frequency, these are: HbS (sickle cell disease and trait), C, E, Lepore, G-Philadelphia, HbH disease, D-Los Angeles, Koln, Constant Spring, O-Arab. Other variants associated with hemolysis, erythrocytosis/polycythemia, microcytosis, cyanosis/hypoxia are routinely identified; however, some will not be detected by routine screening methods and require communication of clinical findings to prompt indicated reflex testing options. Alpha-thalassemia genetic variants are very common in the United States, occurring in approximately 30% of African Americans and accounting for the frequent occurrence of microcytosis in persons of this ethnic group. Some alpha-thalassemia conditions (eg, HbH, Barts) can be identified in the hemoglobin electrophoresis protocol, although Hb Constant Spring may or may not be evident by protein methods alone dependent upon the percentage present. It is important to note, alpha thalassemias that are from only 1 or 2 alpha-globin gene deletions are not recognized by protein studies alone and alpha-gene deletion and duplication testing is required.

Method Name

HBELI, HBEL0: Medical Interpretation

HGBCE: Capillary Electrophoresis

HPLC: Cation Exchange/High-Performance Liquid Chromatography (HPLC)

IEF: Isoelectric Focusing

MASS: Mass Spectrometry (MS)

HPFH: Flow Cytometry

UNHB: Isopropanol and Heat Stability

Report Available

2 to 25 days

Reporting Name

Hb Electrophoresis Evaluation

Reference Values

Hemoglobin Electrophoresis Interpretation

Definitive results and an interpretative report will be provided.

 

Hemoglobin Variant, A2 and F Quantitation

HEMOGLOBIN A

1-30 days: 5.9-77.2%

1-2 months: 7.9-92.4%

3-5 months: 54.7-97.1%

6-8 months: 80.0-98.0%

9-12 months: 86.2-98.0%

13-17 months: 88.8-98.0%

18-23 months: 90.4-98.0%

≥24 months: 95.8-98.0%

 

HEMOGLOBIN A2

1-30 days: 0.0-2.1%

1-2 months: 0.0-2.6%

3-5 months: 1.3-3.1%

≥6 months: 2.0-3.3%

 

HEMOGLOBIN F

1-30 days: 22.8-92.0%

1-2 months: 7.6-89.8%

3-5 months: 1.6-42.2%

6-8 months: 0.0-16.7%

9-12 months: 0.0-10.5%

13-17 months: 0.0-7.9%

18-23 months: 0.0-6.3%

≥24 months: 0.0-0.9%

 

VARIANT 1

0.0

 

VARIANT 2

0.0

 

VARIANT 3

0.0

Interpretation

The hemoglobin (Hb) fractions, including Hb variants are identified and quantitated. An interpretive report that summarizes all testing, including the significance of the findings, is issued.

Method Description

Hemoglobin Electrophoresis:

The CAPILLARYS System is an automated system that uses capillary electrophoresis to separate charged molecules by their electrophoretic mobility in an alkaline buffer. Separation occurs according to the electrolyte pH and electro-osmotic flow. A sample dilution with hemolyzing solution is injected by aspiration. A high voltage protein separation occurs, and direct detection of the hemoglobin-protein fractions is at 415 nm, which is specific to hemoglobin. The resulting electrophoregram peaks are evaluated for pattern abnormalities and are quantified as a percentage of the total hemoglobins present. Examples of position of commonly found hemoglobin fractions are, from cathode to anode: HbA2', C, A2/O-Arab, E, S, D, G-Philadelphia, F, A, Hope, Bart, J, N-Baltimore and H.(Louahabi A, Philippe M, Lali S, Wallemacq P, Maisin D: Evaluation of a new Sebia kit for analysis of hemoglobin fractions and variants on the Capillarys system. Clin Chem Lab Med. 2006;44[3]:340-345; instruction manual: CAPILLARYS Hemoglobin(E) using the CAPILLARYS 2 flex-piercing instrument. Sebia; 06/2014)

 

High-Performance Liquid Chromatography:

Hemolysate of whole blood is injected into an analysis stream passing through a cation exchange column using high-performance liquid chromatography (HPLC). A preprogrammed gradient controls the elution buffer mixture that also passes through the analytical cartridge. The ionic strength of the elution buffer is raised by increasing the percentage of a second buffer. As the ionic strength of the buffer increases the more strongly retained hemoglobins elute from the cartridge. Absorbance changes are detected by a dual-wavelength filter photometer. Changes in absorbance are displayed as a chromatogram of absorbance versus time.(Huismann TH, Scroeder WA, Brodie AN, Mayson SM, Jakway J: Microchromotography of hemoglobins. III. A simplified procedure for the determination of hemoglobin A2. J Lab Clin Med. 1975;86:700-702; Ou CN, Buffone GJ, Reimer GL, Alpert AJ: High-performance liquid chromatography of human hemoglobins on a new cation exchanger. J Chromatogr. 1983;266:197-205; instruction manual: Bio-Rad Variant II Beta-thalassemia Short Program Instructions for Use, L70203705. Bio-Rad Laboratories, Inc; 11/2011)

Day(s) Performed

Monday through Thursday

Clinical Reference

1. Hoyer JD, Hoffman DR: The thalassemia and hemoglobinopathy syndromes. In: McClatchey KD, Amin HM, Curry JL, eds. Clinical Laboratory Medicine. 2nd ed. Lippincott Williams and Wilkins; 2002:866-895

2. Oliveira JL: Diagnostic strategies in hemoglobinopathy testing, the role of a reference laboratory in the USA. Thalassemia Reports. 2018;8(1). doi: 10.4081/thal.2018.7476

3. Brancaleonai V, Di Pierro E, Motta I, Cappellini MD: Laboratory diagnosis of thalassemia. Int J Lab Haematol. 2016;38(suppl 1):32-40

4. Hartveld CI: State of the art and new developments in molecular diagnostics for hemoglobinopathies in multiethnic societies. Int J Lab Haematol. 2014;36:1-12

5. Szuberski J, Oliveira JL, Hoyer JD: A comprehensive analysis of hemoglobin variants by high-performance liquid chromatography (HPLC). Int J Lab Hematol. 2012 Dec; 34(6):594-604

6. Riou J, Szuberski J, Godart C, et al. Precision of CAPILLARYS 2 for the detection of hemoglobin variants based on their migration positions. Am J Clin Pathol. 2018 Jan 29;149(2):172-180

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83020-Quantitation by electrophoresis

83021-Quantitation by HPLC

82664-Electrophoresis, not elsewhere specified (if appropriate)

83068 (if appropriate)

83789 (if appropriate)

88184 (if appropriate)

83020-26 (if appropriate)

 

LOINC Code Information

Test ID Test Order Name Order LOINC Value
HBEL1 Hb Electrophoresis Evaluation 94538-6

 

Result ID Test Result Name Result LOINC Value
41927 Hb A 20572-4
65615 HPLC Hb Variant, B No LOINC Needed
608088 Hb Electrophoresis Interpretation 49316-3
609421 Hb Electrophoresis Interp Cancel No LOINC Needed
41928 Hb F 4576-5
41929 Hb A2 4551-8
41930 Variant 1 24469-9
41931 Variant 2 24469-9
41932 Variant 3 24469-9
41933 HGBCE Interpretation 78748-1

Profile Information

Test ID Reporting Name Available Separately Always Performed
HBELI Hb Electrophoresis Interpretation No Yes
HGBCE Hb Variant, A2 and F Quantitation,B Yes Yes
HPLC HPLC Hb Variant, B No Yes

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
HPFH Hb F Distribution, B No No
MASS Hb Variant by Mass Spec, B No No
SDEX Sickle Solubility, B Yes No
IEF Isoelectric Focusing, B No No
UNHB Hb Stability, B No No
ATHAL Alpha-Globin Gene Analysis Yes No
WASQR Alpha Globin Gene Sequencing, B Yes, (Order WASEQ) No
WBSQR Beta Globin Gene Sequencing, B Yes, (Order WBSEQ) No
WBDDR Beta Globin Cluster Locus Del/Dup,B Yes, (Order WBDD) No
WGSQR Gamma Globin Full Gene Sequencing Yes, (Order WGSEQ) No
HBEL0 Hb Electrophoresis Summary Interp No No