Test Catalog

Anti-platelet antibodies (MAIPA)

Code: 4814

Type: Estudis plaquetaris

Clinical information

Diagnostic Utility:

  • The MAIPA technique (Platelet Antigen Immobilization using Monoclonal Antibodies) is the classical technique used for the investigation of specific anti-platelet alloantibodies.
  • The platelet-specific antigens are called HPA (Human Platelet Antigens) and are located on different platelet membrane glycoproteins, mainly on GP IIb/IIIa, Ib/IX/V, and Ia/IIa.
  • Alloantibodies directed against HPA antigens are involved in cases of platelet refractoriness, fetal/neonatal alloimmune thrombocytopenia (FNAIT), and post-transfusion purpura (PTP).
  • With the MAIPA technique, we can also detect the presence of free anti-platelet autoantibodies in the serum. In this case, a pan-reactivity pattern is observed against one or several platelet membrane GPs.

Method:

  • In the MAIPA technique, the serum in question is incubated with platelets with known HPA genotypes; subsequently, the GPs to be studied are captured using monoclonal antibodies.
  • In the final step of this technique, human antiglobulin (AHG) conjugated with peroxidase is added, and finally the corresponding substrate; the obtained reaction highlights the presence or absence of AHG fixed to each of the GPs, which allows the identification of anti-platelet antibodies in the serums studied.
  • There are commercial techniques (ELISA Kits or Luminex Kits) that allow the study of antibodies against platelet membrane GPs (IIbIIIa, IaIIa, IbIX, and GP IV), equivalent to the MAIPA technique.

Results:

The results of the MAIPA study are:  

  • Negative Study: no antibodies are detected against the studied glycoproteins
  • Positive Study:
    •  A pan-reactivity pattern is observed against one or more platelet membrane GPs; suggestive of the presence of autoantibodies.
    •  Reactivity is observed against an HPA antigen; a specific alloantibody against an HPA antigen is detected (e.g. anti-HPA-1a).

Response Time:

14 working days

Specimen information

Sample: serum or plasma
Tubes: one EDTA tube or serum (minimum volume of 1 ml of plasma or serum)
Stability: At room temperature or at 4°C: 3 days
Transport instructions: At room temperature or at 4°C
Reason for rejection: Highly hemolyzed sample

Administrative information

BST Code: 4814
Test Description: Study of anti-platelet antibodies by MAIPA
Synonyms:

  • Study of antibodies against GP IIb/IIIa, IaIIa, and IbIX.
  • Study of anti-platelet antibodies on solid phase

Section: Immunohematology
BST Rate: Check the updated rates here.

Profiles: The MAIPA test is performed in the following studies:

  • Neonatal Alloimmune Thrombocytopenia (NAIT)
  • Platelet Refractoriness Study
  • Pseudothrombocytopenia Transfusion Reactions
  • In all patients where the presence of allo-antibodies against HPA antigens is to be investigated.

References

Kiefel V, Santoso S, Weisheit M, Mueller-Eckhardt C. Monoclonal antibody-specific immobilization of platelet antigens (MAIPA): a new tool for the identification of platelet-reactive antibodies. Blood 1987;70:1722-6.

Lucas GF, Rogers SE. Evaluation of an enzyme-linked immunosorbent assay kit (GTI PakPlus) for the detection of antibodies against human platelet antigens. Transfus Med 1999;9:63-7.

Porcelijn L, Huiskes E, Comijs-van Osselen I, Chhatta A, Rathore V, Meyers M, de Haas M. A new bead-based human platelet antigen antibodies detection assay versus the monoclonal antibody immobilization of platelet antigens assay. Transfusion. 2014 Jun;54(6):1486-92