PLATELET AUTOANTIBODY PANEL

General Information

HLAB/HOL Code: PLABS
UPHSM LIS Test #: 8290
Schedule:
Testing Time:
Testing Lab: Labcorp

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume: 12 (4 mL in each of 3 tubes) mL
Temperature: Ambient
Tube Type: Lavender-Top EDTA
Collection Info:
Specimen:  Whole blood

Volume:  12 mL (4 mL in each of three tubes)

Container:  Lavender-top (EDTA) tube

Storage Instructions:  Maintain specimen at room temperature.



Causes for Rejection:  Hemolysis; specimen more than 72 hour old





Methods

Solid-phase enzyme-linked immunoassay after elution of antibodies from platelets  

Clinical Utilities

Detect the presence of an autoantibody that have been associated with autoimmune thrombocytopenic purpura (AITP). Autoimmune thrombocytopenic purpura (AITP) occurs when platelet autoantibodies destroy an individual's platelets resulting in a persistent thrombocytopenia.[1] In children,AITP is usually self-limiting and frequently resolves spontaneously.[2] AITP in children is often associated to a transient viral infection. Approximately 15% of childhoodAITP cases become chronic.[1] AITP in adults often has an insidious onset and resulting in chronic thrombocytopenia that rarely remits spontaneously. This condition can be idiopathic or, in some cases, associated with another autoimmune condition (i.e., SLE) or malignancy. This platelet autoantibody panel is designed to detect IgG antibodies that are bound to platelet-specific glycoproteinsIIb/IIIa,Ib/IX or Ia/IIa. Antibodies directed against endogenous platelet membrane antigens have been associated with AITP by several laboratories.  A recent study reported that testing for platelet associated antibodies to IIb/IIa, Ib/IX and Ia/IIa had a sensitivity of 53% and a specificity of 72% for diagnosing AITP.  These results are consistent with the findings from previous studies showing sensitivity ranging from 49% - 66% and specificity ranging from 78% - 92% using assays to detect platelet- associated antibodies to platelet-specific glycoproteins IIb/IIIa and Ib/IX. Tests that measure antibodies to specific platelet antigens have been shown to provide clinical information that is superior to older assays that measured total platelet- associated immunoglobulin G, assays that have often been referred to as PAIgG assays. While PAIgG assays are frequently positive in patients with AITP, they are also often positive in patients with non-immune thrombocytopenic disorders.  In contrast to the older PAIgG assays, the platelet antigen specific panel has been shown to have a relatively high positive predictive value of 90%. However, the platelet antigen specific panel has been shown to have a low negative predictive value of 24%, indicating that a negative value should not be interpreted as ruling out the condition.  

Clinical Limitation:
This assay is not designed to detect antibodies associated with heparin-induced thrombocytopenia (HIT) the most common drug-induced immune thrombocytopenia. While a positive result is useful in supporting the diagnosis of ITP, negative results do not necessarily rule out the condition.

Test Includes:
Platelet-associated antibodies to platelet-specific glycoproteins IIb/IIIa, Ib/IX, and Ia/IIa

CPT Codes

86022 X 3

* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Reference Range

Negative