Test Id : PLAFL
Platelet Surface Glycoprotein by Flow Cytometry, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
Identification of markedly decreased CD41 (GPIIb) and CD61 (GPIIIa) expression levels, which are diagnostic for Glanzmann thrombasthenia
Identification of markedly decreased CD42a (GPIX) and CD42b (GPIb-alpha) expression levels, which are diagnostic for Bernard-Soulier syndrome
Identification of decreased GPVI expression, which suggests collagen receptor deficiency
Identification of decreased CD49b (GPIa), which suggests collagen receptor deficiency
Highlights
This test serves as a confirmatory test for platelet aggregation studies.
Markedly decreased platelet surface glycoprotein expression levels are diagnostic for various hereditary or acquired platelet disorders.
Method Name
A short description of the method used to perform the test
Immunophenotyping
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Specimen Type
Describes the specimen type validated for testing
Whole Blood ACD
Shipping Instructions
Specimen must be shipped ambient and arrive within 4 days of draw.
Ship specimen overnight in an Ambient Shipping Box-Critical Specimens Only (T668) following the instructions in the mailer.
Necessary Information
Platelet Esoteric Testing Patient Information is required. Testing may proceed without the patient information, however, the information aids in providing a more thorough interpretation. Ordering providers are strongly encouraged to fill out the form and send with the specimen.
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Supplies: Ambient Shipping Box-Critical Specimens Only (T668)
Collection Container/Tube: ACD solution A or B
Specimen Volume: 6 mL
Pediatric Volume: 1 mL
Collection Instructions: Do not transfer blood to other containers.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
1. Platelet Esoteric Testing Patient Information is required.
2. If not ordering electronically, complete, print, and send a Coagulation Test Request (T753) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
Adult: 1 mL
Pediatric 200 mcL
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Gross hemolysis | Reject |
| Fully Clotted | Reject |
| Gross lipemia | OK |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole Blood ACD | Ambient | 4 days |
Useful For
Suggests clinical disorders or settings where the test may be helpful
Identification of markedly decreased CD41 (GPIIb) and CD61 (GPIIIa) expression levels, which are diagnostic for Glanzmann thrombasthenia
Identification of markedly decreased CD42a (GPIX) and CD42b (GPIb-alpha) expression levels, which are diagnostic for Bernard-Soulier syndrome
Identification of decreased GPVI expression, which suggests collagen receptor deficiency
Identification of decreased CD49b (GPIa), which suggests collagen receptor deficiency
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Platelets have essential roles in primary hemostasis. Exposed collagen at a vascular damage site can activate platelets via collagen receptor GPVI and GPIa and bind shear-stretched multimeric VWF proteins, which subsequently interact with the platelet surface receptor, GPIb-V-IX. Upon full activation, platelets can aggregate by binding to fibrinogen through activated GPIIb-GPIIIa receptors. Deficiency of platelet surface glycoproteins can cause bleeding diathesis.
Platelet flow cytometric analysis is the preferred method to assess hereditary platelet disorders due to quantitative surface glycoprotein (GP) deficiencies. GP expression levels can be measured by using fluorescent-conjugated GP-specific antibodies and their fluorescent intensities can be compared to normal ranges of various glycoproteins.
| CD Number | Glycoprotein Name | Integrin Name |
| CD41 | GPIIb | Alpha 2b |
| CD42a | GPIX | NA |
| CD42b | GPIb-alpha | NA |
| CD49b | GPIa | Alpha 2 |
| CD61 | GPIIIa | Beta 3 |
| NA | GPVI | NA |
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.
GPIIb CD41: > or =70.0%
GPIIIa CD61: > or =70.0%
GPIX CD42a: > or =70.0%
GPIb-alpha CD42b: > or =70.0%
GPIa CD49b: > or =60.0%
Interpretation
Provides information to assist in interpretation of the test results
| CD Markers | % Reference Range Median | Comments |
| CD41 and CD61 | 50%-69% (Marginally) | Marginally decreased platelet surface receptors CD41 (GPIIb) and CD61 (GPIIIa) are of uncertain clinical significance. This finding could be a laboratory artifact due to a suboptimal sample condition, benign polymorphisms, or a heterozygous state of Glanzmann thrombasthenia. Recommend correlation with patient’s clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. |
| 30%-50%: (Moderately) <30%: (Markedly) | Platelet surface expression of CD41 (GPIIb) and CD61 (GPIIIa) are moderately or markedly decreased. This finding is suggestive of a variant of Glanzmann thrombasthenia. Recommend correlation with patient’s clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. | |
| CD42a and CD42b | 50%-69% (Marginally) | Marginally decreased platelet surface receptors CD42a (GPIX) and CD42b (GPIb-alpha) are of uncertain clinical significance. This finding could be a laboratory artifact due to a suboptimal sample condition, benign polymorphisms, or a heterozygous state of Bernard-Soulier syndrome. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. |
| 30%-50%: (Moderately) <30%: (Markedly) | Platelet surface expression of CD42a (GPIX) and CD42b (GPIb-alpha) are moderately or markedly decreased. This finding is suggestive of a variant of Bernard-Soulier syndrome. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. | |
| CD49b | 30%-59% (Marginally) | Marginally decreased platelet surface receptor CD49b (GPIa) is of uncertain clinical significance. This finding could be a laboratory artifact due to a suboptimal sample condition, a benign polymorphism, or a variant of platelet collagen receptor glycoprotein Ia/IIa deficiency. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. |
| 10%-30% (moderately) <10% (Markedly) | Platelet surface expression of CD49b (GPIa) is moderately or markedly decreased. This finding is suggestive for a variant of a variant of platelet collagen receptor glycoprotein Ia/IIa deficiency. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. | |
| GPVI | 50%-69% (Marginally) | Marginally decreased platelet surface receptor glycoprotein VI (GPVI) is of uncertain clinical significance. This finding could be a laboratory artifact due to a suboptimal sample condition, a benign polymorphism or a variant of platelet collagen receptor GPVI deficiency. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. |
| 30%-50% (moderately) <30% (Markedly) | Platelet surface expression of glycoprotein VI (GPVI) is moderately or markedly decreased. This finding is suggestive of a variant of a variant of platelet collagen receptor GPVI deficiency. Recommend correlation with patient's clinical findings and results of platelet functional studies, and consider repeating platelet glycoprotein profile studies by flow cytometry to verify the present finding if clinically indicated. |
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Suboptimal sample conditions due to improper blood draw, transportation, or storage may cause fluctuation of platelet surface receptors and consequently influence the results of platelet surface receptor measurement by flow cytometry.
Supportive Data
The platelet glycoprotein flow cytometry method was established in the Mayo Clinic Special Coagulation Laboratory in 2009. Between the years of 2009 to 2014, a total of 155 clinical patients at Mayo Clinic were tested. The flow cytometry results were compared with the final impressions of platelet light transmission aggregation testing. There were 7 samples that had flow cytometric features of Glanzmann thrombasthenia, 2 samples that had flow cytometric features of Bernard-Soulier syndrome, and 3 samples that had flow cytometric features of May-Hegglin anomaly. All flow cytometric results were concordant with platelet light transmission aggregation results and other clinical findings.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Miller, JL. Glycoprotein analysis for the diagnostic evaluation of platelet disorders. Semin Thromb Hemost. 2009;35(2):224-232
2. Kannan M, Ahmad F, Yadav BK, et al. Carrier detection in Glanzmann thrombasthenia: comparison of flow cytometry and Western blot with respect to DNA mutation. Am J Clin Pathol. 2008;130(1):93-98
3. Savoia A, Pastore A, De Rocco D, et al: Clinical and genetic aspects of Bernard-Soulier syndrome: searching for genotype/phenotype correlations. Haematologica. 2011;96(3):417-423
4. Nurden AT, Freson K, Selifsohn U. Inherited platelet disorders. Haemophilia. 2012;18(4):154-160
5. Spurgeon BEJ, Naseem KM. Platelet Flow Cytometry: Instrument Setup, Controls, and Panel Performance. Cytometry B Clin Cytom. 2020;98(1):19-27
6. Frelinger AL, 3rd, Rivera J, Connor DE, et al. Consensus recommendations on flow cytometry for the assessment of inherited and acquired disorders of platelet number and function: Communication from the ISTH SSC Subcommittee on Platelet Physiology. J Thromb Haemost. 2021;19(12):3193-3202
Method Description
Describes how the test is performed and provides a method-specific reference
Flow cytometric immunophenotyping of peripheral blood platelets is performed using the following antibodies:
Panel: CD41 (IIb), CD42a (IX), CD42b (Ib-alpha), CD49b (GPIa), CD61 (GPIIIa), and GPVI.
For sample quality purposes, CD62P is evaluated.
Using whole blood collected in ACD (A or B), platelet surface GPIa, Ib-alpha, IIb, IIIa, VI and IX expression levels are measured by flow cytometry method. Platelets in whole blood are stained with various fluorochrome-labeled primary antibodies and fixed. Then the platelet surface fluorescent intensities of various bound antibodies are measured by flow cytometers. Platelets are first gated by forward and side scatter. Mean fluorescent intensities are recorded and converted to percentage of a median fluorescent intensity of a normal donor study of 20 healthy donors. If the percentage of expression of a glycoprotein (GP) is lower than the corresponding normal range, a deficiency of a GP is detected.(Unpublished Mayo Method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Monday through Saturday
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
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
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
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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 instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US 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 Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
88184-Flow cytometry; first cell surface, cytoplasmic or nuclear marker
88185-Flow cytometry; additional cell surface, cytoplasmic or nuclear marker (each) X5
88187-Flow cytometry interpretation, 2 to 8 markers
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| PLAFL | Platelet Glycoprotein Flow, B | 93320-0 |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| CK111 | GPIIb CD41 | 93319-2 |
| CK112 | GPIIIa CD61 | 93318-4 |
| CK113 | GPIX CD42a | 93317-6 |
| CK114 | GPIb-alpha CD42b | 93316-8 |
| CK115 | GPIa CD49b | 93315-0 |
| CK116 | GPVI | 93314-3 |
| CK117 | Final Diagnosis | 93313-5 |