Test Catalog

Test ID: PLABN    
Platelet Antibody Screen, Serum

Useful For Suggests clinical disorders or settings where the test may be helpful

Detecting alloantibodies to epitopes on platelet glycoproteins IIb/IIIa, Ib/Ix, Ia/IIa, IV and HLA Class I antigens to evaluate cases of immune mediated refractoriness to platelet transfusions, posttransfusion purpura, or neonatal alloimmune thrombocytopenia

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

See Platelet Antibody Testing Algorithm in Special Instructions.

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" carried on platelet cytoplasmic membranes. Serum platelet antibody test is optimized to identify the presence of platelet allo-antibodies in the patient.


Platelet alloantibodies are involved in several clinical situations such as:

-Immune mediated refractoriness to platelet transfusions usually due to antibodies to HLA class I and sometimes to antibodies specific to platelet antigens.

-Neonatal alloimmune thrombocytopenia (NAIT)

-Posttransfusion purpura (PTP), which are usually associated with platelet-specific antibodies


This test is not recommended for the diagnosis of immune thrombocytopenia (ITP) 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 instead (CBPAN / Cell Bound Platelet Auto-Antibody Screen, Blood).

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.

Not applicable

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Erroneous results can occur from bacterial contamination of test materials, inadequate incubation periods, inadequate washing or decanting of test wells, exposure of substrate to stray light, omission of test reagents, exposure to higher or lower than prescribed temperature requirements, insufficient or excessive platelets, or omission of steps.


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 HPA polymorphic variants located on GPIIb/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 HLA Class I antigens may not be detected using this product.


This test has not been evaluated for the detection of autoantibodies to platelet antigens. Instead, CBPAN / Cell-Bound Platelet Autoantibody Screen, Blood should be performed.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Kiefel V, Santoso S, Weisheit M, et al: Monoclonal antibody-specific immobilization of platelet antigens (MAIPA): A new tool for the identification of platelet-reactive antibodies. Blood 1987;70:1722-1726

2. Moore SB, De Goey SR: Serum platelet antibody testing: evaluation of solid-phase enzyme immunoassay and comparison with indirect immunofluorescence. Am J Clin Pathol 1998;109:190-195

3. Warkentin TE, Smith JW: The alloimmune thrombocytopenic syndromes. Transfus Med Rev 1997;11:296-307

4. Metcalfe P, Watkins NA, Ouwehand WH, et al: Nomenclature of human platelet antigens (HPA) VoxSang 2003;85:240-245

5. Liebman HA: Immune thrombocytopenia (ITP): an historical perspective. Hematology Am Soc Hematol Educ Program 2008;(1):205 DOI:10.1182

6. Kjeldsen-Kragh J, Killie MK, Tomter G, et al: A screening and intervention program aimed to reduce mortality and serious morbidity associated with severe neonatal alloimmune thrombocytopenia. Blood 2007;110:883-889

7. Post transfusion purpura (PTP). In Essential Haematology. Edited by AV Hoffbrand, PAH Moss, JE Pettit. Fifth edition. Blackwell Publishing. 2006

Special Instructions Library of PDFs including pertinent information and forms related to the test