Test ID: CBPA
Cell-Bound Platelet Autoantibody, Solid Phase, Blood
Secondary ID 
A test code used for billing and in test definitions created prior to November 2011
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
Useful For Suggests clinical disorders or settings where the test may be helpful
Diagnosis of idiopathic (autoimmune) thrombocytopenia purpura
Diagnosis of immune thrombocytopenia associated with systemic lupus erythematosus or other disorders associated with autoimmune phenomena
Method Name A short description of the method used to perform the test
Enzyme-Linked Immunoabsorbent Assay (ELISA)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Aliases Lists additional common names for a test, as an aid in searching
Cell-Bound Platelet Antibody Test, Platelet-Rich Plasma
Direct Platelet Antibody
Platelet Antibody, Direct
Platelet Associated IgG (Immunoglobulin)
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.
The patient must have a platelet count >10,000/microliter.
Specimen must arrive within 48 hours. Draw specimen Monday through Thursday only and not the day before a holiday. Specimen should be drawn and packaged as close to shipping time as possible.
Container/Tube: Lavender top (EDTA)
Specimen Volume: 20 mL
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.
Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected
| Hemolysis | NA |
| Lipemia | NA |
| Icterus | NA |
| Other | Specimen older than 48 hours |
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood EDTA | Refrigerated | 48 hours |
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Platelet antibodies may be allo- or autoantibodies and may be directed to a wide range of antigenic "targets" on platelet cytoplasmic membranes. Alloantibodies are involved in clinical conditions such as platelet refractoriness, neonatal alloimmune thrombocytopenia, and posttransfusion purpura. In contrast, platelet autoantibodies are involved in idiopathic (autoimmune) thrombocytopenic purpura, the thrombocytopenia associated with systemic lupus erythematosus, and with the thrombocytopenia associated with sepsis (usually bacterial, occasionally fungal). Sometimes platelet autoantibodies can be detected in the patient's serum, but extensive data demonstrate that direct detection of immunologically bound immunoglobulin (usually IgG) is considerably more sensitive for autoantibody detection. The method consists of an elution step followed by solid-phase enzyme-linked immunoassay, which not only concentrates the cell-bound antibodies, but identifies the target glycoproteins against which they are directed. In most studies of autoimmune thrombocytopenia, the majority (approximately 80%) of detected autoantibodies were directed to the platelet glycoprotein IIb/IIIa and, more rarely, to other glycoproteins such as Ib/IX (approximately 11%) or Ia/IIa.
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.
An interpretive report will be provided.
Interpretation Provides information to assist in interpretation of the test results
A positive test, particularly to GP IIB/IIIa or Ib/IX, in the presence of thrombocytopenia (not explained by other findings) is consistent with idiopathic (autoimmune) thrombocytopenic purpura.
Similarly, a positive test in a thrombocytopenic patient with systemic lupus erythematosus is consistent with an autoimmune cause.
Patients who are septic may also have a positive test with reactivity against most glycoproteins.
Presence of reactivity to some glycoproteins has no clearly established clinical significance.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Results of this test should be interpreted in light of the clinical circumstances.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. McMillan R, Tani P, Millard F, et al: Platelet-associated and plasma anti-glycoprotein autoantibodies in chronic ITP. Blood 1987;70:1040-1045
2. Moore SB, Wick MR, Richardson LM: Immune thrombocytopenias: tests for platelet antibodies. Mayo Clin Proc 1984;59:860-863
3. Kiefel V, Santoso S, Weisheit M, Mueller-Eckhardt C: Monoclonal antibody-specific immobilization of platelet antigens (MAIPA): a new tool for the identification of platelet-reactive antibodies. Blood 1987;70:1722-1726
3. Moore SB, DeGoey SR: Serum platelet antibody testing: evaluation of solid-phase enzyme immunoassay and comparison with indirect immunofluorescence. Am J Clin Pathol 1998;109:190-195
Method Description Describes how the test is performed and provides a method-specific reference
Elution followed by enzyme-linked immunoassay. (Moore SB, Wick MR, Richardson LM: Immune thrombocytopenias: tests for platelet antibodies. Mayo Clin Proc 1984;59:860-863; Davoren A, Bussel J, Curtis BR, et al: Prospective evaluation of a new platelet glycoprotein (GP)-specific assay (PakAuto) in the diagnosis of autoimmune thrombocytopenia. Am J Hematol 2005;78:193–197)
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 Friday; 7:30 a,m.-5:00 p.m.
Saturday; 10:00 a.m.-6:00 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.
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.
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.
86022
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 |
|---|---|---|
| CBP_A | Cell Bound Platelet Autoantibody, B | In Process |
| CMT27 | Comment | 48767-8 |
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