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HelpTest Code PLABN Platelet Antibody Screen, Serum
Useful For
Detecting alloantibodies to epitopes on platelet glycoproteins IIb/IIIa, Ib/Ix, Ia/IIa, IV and class I human leukocyte antigens to evaluate cases of immune mediated refractoriness to platelet transfusions, posttransfusion purpura, or neonatal alloimmune thrombocytopenia
Special Instructions
Method Name
Solid Phase Enzyme-Linked Immunosorbent Assay (ELISA)
Reporting Name
Platelet Ab Screen, SSpecimen Type
Serum RedOrdering Guidance
For neonate testing, consider sending a maternal specimen instead of a neonate specimen as unbound platelet antibodies may not be detected in the neonate serum.
This test is not recommended for the diagnosis of immune thrombocytopenia or autoimmune thrombocytopenia. Tests that are optimized to detect antibodies bound to the platelets will be useful in these situations; cell-bound platelet antibody (direct) test is strongly recommended.
Necessary Information
If ordering electronically, answer all prompt questions for timely result reporting:
1. Reason for request is required for result interpretation.
a. Use provided diagnosis options if appropriate. If specific diagnosis is unknown, select the generic answer of alloimmune thrombocytopenia.
b. Record only the diagnosis pertaining to this test.
c. Record diagnosis description instead of code.
2. Indicate if patient has had intravenous immunoglobulin (IVIg) therapy in the last month: Yes or No
Specimen Required
Patient Preparation: Do not collect within 72 hours of a platelet transfusion. Transfused platelets will interfere with this assay.
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial.
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Frozen (preferred) | 365 days | |
| Refrigerated | 48 hours |
Reject Due To
| Gross hemolysis | Reject |
Clinical Information
Platelet antibodies may be allo- or autoantibodies and may be directed to a wide range of antigenic "targets" carried on platelet cytoplasmic membranes. Serum platelet antibody test is optimized to identify the presence of platelet alloantibodies in the patient.
Platelet alloantibodies are involved in several clinical situations such as:
-Immune mediated refractoriness to platelet transfusions usually due to antibodies to class I human leukocyte antigens and sometimes to antibodies specific to platelet antigens.
-Neonatal alloimmune thrombocytopenia
-Posttransfusion purpura, which are usually associated with platelet-specific antibodies
Reference Values
Not applicable
Cautions
This assay is intended for use as a screening assay. The results of this assay should not be used as the sole basis for a clinical decision. The reaction patterns a test sample produces with this product should not be relied on solely to establish the identity of a platelet antibody. Therefore, positive or negative results obtained using this assay should be used in conjunction with clinical findings or other serological tests.
Some low-titer, low-avidity antibodies may not be detected using this assay.
The presence of other human platelet antigen (HPA) polymorphic variants located on glycoprotein (GP)IIb/IIIa (HPA-6, 7, 8, 9, 10, 11, 14, 16, 17, 19, 20, 21), GPIa/IIa (HPA-13, 18), and GPIb/IX (HPA-12) has not been determined for the antigens captured in this kit. Antibodies to these systems may be reactive in this assay.
Antibodies to low incidence class I human leukocyte antigens may not be detected using this product.
This test has not been evaluated for the detection of autoantibodies to platelet antigens.
Method Description
Patient serum is added to microwells coated with platelet and human leukocyte antigen (HLA) glycoproteins, allowing antibody, if present, to bind. Unbound antibodies are then washed away. An alkaline phosphatase-labeled antihuman globulin reagent (anti-IgG/A/M) is added to the microwells and incubated. The unbound anti-IgG/A/M is washed away and the substrate p-nitrophenylphosphate (PNPP) is added to the wells and incubated. The reaction is stopped with stopping solution. The optical density of the color that develops is measured in a spectrophotometer and results are interpreted.(Package insert: PakPlus. Immucor GTI Diagnostics; 303469.IFUEN Rev E; 07/2015)
Day(s) Performed
Monday through Friday
Report Available
2 to 4 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86022
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| PLABN | Platelet Ab Screen, S | 95270-5 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| PTL01 | Overall Result | 24375-8 |
| PTL02 | Interpretation | 59466-3 |
| PTL03 | GPIIb/IIIa (Cell-1) | 48505-2 |
| PTL04 | GPIIb/IIIa (Cell-2) | 48505-2 |
| PTL05 | GPIa/IIa (Cell-1) | 47084-9 |
| PTL06 | GPIa/IIa (Cell-2) | 47084-9 |
| PTL07 | GPIb/IX | 48506-0 |
| PTL08 | GPIV | 87757-1 |
| PTL09 | HLA Class I | 95269-7 |
| PTL15 | Reason for request? | 29548-5 |
| PTL16 | IVIg in last month? | 95268-9 |
Testing Algorithm
For more information see Platelet Antibody Testing Algorithm.
Interpretation
This assay screens patient sera for platelet-reactive antibodies via enzyme-linked immunosorbent assay.