Platelet Antibody, Indirect

Platelet Antibody, Indirect

Alternate Test Name

Platelet Antibody Screen, Serum

Mnemonic

LAB767
PLABB

Category

Sendouts

Methodology

Solid Phase Enzyme-Linked Immunosorbent Assay (ELISA)

Test Performance Schedule

Monday - Saturday

Result Availability

2 - 4 days

Container

Red top (serum) tube

Volume

Pref. Vol.: 1.5 mL
Min. Vol.: 0.5 mL

Collection Instructions

• Routine venipuncture
•For newborns less than 30 days old, collect sample from mother
•Immediatelyafter collection,gentlyinvert tube 5-10 times
•Promptlycentrifuge 15 minutes
•Immediatelytransfer serum to separate plastic tube
• Freeze

Transportation Instructions

Frozen

Stability

• Room Temperature: Unacceptable
• Refrigerated: 48 hours
• Frozen: 365 days

Causes for Rejection

• Grossly hemolyzed specimen
• Serum gel tube

Remarks

Necessary information:
• Reason for request is required for result interpretation
• Indicate if patient has had intravenous immunoglobulin (IVIg) therapy in the last month
• Indicate if the patient has received a platelet transfusion within 72 hours of collection
• Record the most recent platelet count, if available

CPT Codes

86022

Effective/Revised

11/19/2019

This is the primary test for detection of platelet-specific antibodies. It is not recommended for the diagnosis of immune thrombocytopenic purpura (ITP). This test will detect both allo and autoantibodies, but will not distinguish between them. Results of this test should be used in conjunction with clinical findings and other serological tests. Antibodies directed to antigens found on platelets are associated with many different clinical situations. Immune thrombocytopenic purpura (ITP) is a destructive thrombocytopenia caused by autoantibodies. Neonatal alloimmune thrombocytopenia (NATP) and post-transfusion purpura (PTP) are diseases where thrombocytopenia is caused by platelet-specific alloantibodies. HLA alloantibodies do not cause thrombocytopenia, but are commonly associated with refractoriness to platelet transfusions.

This test is designed to detect antibodies to platelet glycoproteins IIb/IIIa (HPA-1a/1b [PlA1 and PlA2], HPA-3a/3b, and HPA-4a), Ia/IIA (HPA-5a/5b), Ib/IX, and IV. In addition, this test will also detect antibodies to HLA Class I antigens (HLA-A-B).

Testing for neonatal alloimmune thrombocytopenia should be performed using a maternal serum, since platelet antibody may not be detected in a neonatal serum. False negative results are common in infant samples.