Hemoglobin S and Hemoglobin F Quantitation for Therapeutic Monitoring, Blood
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Monitoring patients with sickling disorders who have received hydroxyurea or transfusion therapy
Reflex Tests Lists test(s) that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial test(s)
|Test ID||Reporting Name||Available Separately||Always Performed|
|SDEX||Hemoglobin S, Scrn, B||Yes||No|
Testing Algorithm Delineates situation(s) when tests are added to the initial order. This includes reflex and additional tests.
If hemoglobin S is detected, hemoglobin S screen will be performed, when appropriate, at an additional charge.
Cation Exchange/High-Performance Liquid Chromatography (HPLC)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Hb S/F Therapeutic Monitoring, B
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Preferred: Lavender top (EDTA)
Acceptable: ACD, heparin
Specimen Volume: 6 mL
Collection Instructions: Do not transfer blood to other containers.
Additional Information: Patient's age is required.
Forms: If not ordering electronically, please submit a Hematopathology/Molecular Oncology Request Form (Supply T241) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild OK; Gross reject
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Whole blood||Refrigerated||7 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
The treatment of red blood cell sickling disorders may involve many therapeutic modalities. Two of the most important and beneficial are treatment with hydroxyurea and chronic transfusion therapy. Hydroxyurea causes elevation of hemoglobin F (Hb F) levels, and transfusion serves to lower the percentage of hemoglobin S (Hb S). Both of these therapeutic modalities act to lessen the number and severity of sickling crises. Thus, periodic monitoring of Hb F and Hb S levels are needed to guide further therapy.
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
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%
> or =24 months: 0.0-0.9%
All ages: 0.0%
Optimal levels of hemoglobin S and hemoglobin F are patient specific and depend on a number of factors including response to therapy.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is not intended for diagnostic purposes; thus, it is assumed the patient's diagnosis is established. If the patient has never been studied, hemoglobin electrophoresis is necessary (see HBELC / Hemoglobin Electrophoresis Cascade, Blood).
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. The Management of Sickle Cell Disease. Fourth edition. Bethesda, MD: National Institutes of Health. National Heart, Lung, and Body Institute, 2002
2. Rosse WF, Telen M, Ware R: Transfusion Support for Patients with Sickle Cell Disease. Bethesda, MD: American Association of Blood Banks. 1998
3. Ferster A, Tahriri P, Vermylen C, et al: Five years of experience with hydroxyurea in children and young adults with sickle cell disease. Blood 2001;97:3268-3632
4. Charache S, Terrin ML, Moore RD, et al: Effect of hydroxyurea on the frequency of painful crises in sickle cell anemia. Investigators of the Multicenter Study of Hydroxyurea in Sickle Cell Anemia. N Engl J Med 1995;332:1317-1322
Method Description Describes how the test is performed and provides a method-specific reference
This test is performed via cation-exchange HPLC. Hemolyzed specimens are maintained at 12 degrees C + or - 2 degrees C in the automatic specimen chamber. The specimens are then sequentially injected into the analysis stream at 6.5 minute intervals for a throughput of 9 specimens per hour. Two dual-piston pumps and a preprogrammed gradient control the elution buffer mixture passing through the analytical cartridge. The ionic strength of the elution buffer mixture is increased by raising the percentage contribution of elution buffer 2. As the ionic strength of the mixture increases, more strongly retained hemoglobins will elute from the analytical cartridge.
A dual-wavelength filter photometer (415 and 690 nm) monitors the elution from the cartridge. As the hemoglobins elute from the cartridge and pass through the photometer flow cell, changes in absorbance at 415 nm are detected. The 690 nm secondary filter corrects the baseline for changes caused by the mixing of different ionic strength buffers. Changes in absorbance are monitored over time, producing a chromatogram. A built-in integrator performs reduction of the raw detector signal data collected from each analysis.
The elapsed time from the injection of the specimen to the apex of a hemoglobin peak is called the retention time. Each hemoglobin has a characteristic retention time. Windows are established from the most frequently occurring hemoglobins based on their characteristic retention time aid in the interpretation of results.(Kim, HC, Adachi K, Scwartz E: Separation of hemoglobins. In Williams Hematology. Fifth edition. Edited by E Beutler, MA Lichtman, S Coller, TJ Kipps. McGraw-Hill Inc, 1995, pp L37-L38; Ou CN, Buffone GJ, Reimer GL: High-performance liquid chromatography of human hemoglobins on a new cation exchange. J Chromatogr 1983;266:197-205)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Saturday; 7 a.m. and 1 p.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Same day/1 day
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
83021-Quantitation by HPLC
85660-Sickling of RBC, reduction (if appropriate)
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|32247||Hb S/F Interpretation||59466-3|