Platelet Associated Antibodies, Direct Assay
Also known as: PAIG
Use
This test supports the diagnosis of autoimmune thrombocytopenia (AITP) by detecting platelet-associated IgG and/or IgM antibodies. Negative results indicate no excess antibodies, making an immune cause of thrombocytopenia unlikely. Positive results suggest an increased presence of platelet-associated immunoglobulins, possibly indicating an immune-related thrombocytopenia. However, elevated levels may also occur in various other conditions, such as rheumatoid factor antibodies.
Special Instructions
Specimens must be analyzed within 48 hours of collection due to the stability limitations of the whole blood sample. The required blood volume may vary based on the platelet count, ensuring sufficient material for accurate flow cytometry analysis. This assay uses dual staining and flow cytometry to ensure that only platelets are analyzed with minimal blood volume required.
Limitations
This assay does not differentiate between autoantibodies and alloantibodies nor does it specify the types of antiplatelet antibodies such as those targeting HPA-1a. Furthermore, it is not FDA cleared or approved, and results must be carefully interpreted in the context of other clinical findings since a range of conditions can lead to increased platelet-associated antibodies.
New York Approved
Methodology
Cell-based / Cytometry (Flow Cytometry)
Biomarkers
LOINC Codes
- 29497-5
- 29498-3
Result Turnaround Time
2-3 days
Related Documents
For more information, please review the documents below
Specimen
Whole Blood
Volume
4 mL
Minimum Volume
1 mL
Container
Lavender (EDTA) or pink (K2EDTA)
Storage Instructions
CRITICAL ROOM TEMPERATURE.
Causes for Rejection
Clotted, hemolyzed, frozen, or refrigerated specimens. Specimens older than 48 hours.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | Unacceptable |
| Frozen | Unacceptable |