Clinical information
Diagnostic Utility:
- Typing of specific platelet antigens (HPA) is critical for confirming the diagnosis and optimal clinical management of patients with platelet refractoriness, fetal/neonatal alloimmune thrombocytopenia (FNAIT), and post-transfusion purpura (PTP).
- Typing of HPA systems in platelet donors allows for the provision of compatible donors for allo-immunized patients.
- Thanks to the application of molecular biology techniques, significant progress has been made in the field of HPA antigen typing. There are several approaches, all based on the polymerase chain reaction (PCR) technique.
Method:
Prior to determining the HPA genotype, DNA extraction from blood samples in EDTA is required.
The complete platelet genotype study is carried out with the ID HPA XT kit, based on Luminex technology. This kit enables the detection of polymorphisms that determine 12 HPA systems, including the 5 most relevant bi-allelic systems (HPA-1, HPA-2, HPA-3, HPA-5, and HPA-15).
Results:
For each system, there are 3 possible result options. For example:
HPA-1 Platelet Genotype:
- 1a1a (1a polymorphism present, 1b absent)
- 1a1b (heterozygous, has both 1a and 1b antigens)
- 1b1b (homozygous for 1b antigen; 1a absent)
Precautions:
In patients with very severe leukopenia, it is sometimes not possible to obtain sufficient DNA to perform the platelet genotype study.
Response Time:
10 working days
Specimen information
Sample: Peripheral Blood
Tubes: 1 tube of 5 ml of EDTA K3
Stability: At room temperature or at 4°C: 7 days
Transport instructions: Preferably at room temperature
Reason for rejection: Highly hemolyzed sample
Administrative information
BST Code: 4818
Test Description: Platelet Genotyping
Synonyms: --
Section: Immunohematology
BST Rate: Check the updated rates here.
Profiles:
Test 4818 is included in the Platelet Refractoriness and Neonatal Alloimmune Thrombocytopenia (NAIT) profile.
References
Kirstin Finning, Radhika Bhandari, Fiona Sellers, Nicoletta Revelli, Maria Antonietta Villa, Eduardo Muñiz-Díaz and Núria Nogués. Evaluation of red blood cell and platelet antigen genotyping platforms (ID CORE XT/ID HPA XT) in routine clinical practice. Blood Transfus. 2016 Mar; 14(2): 160-167.