Clinical information
Diagnostic Utility:
- Platelet transfusion refractoriness in some patients may be due to the presence of antibodies that bind to antigens present on the platelet membrane, causing them to be rapidly destroyed.
- The study of platelet refractoriness aims to investigate the presence of anti-HLA class I antibodies and anti-platelet antibodies in the serum of refractory patients. The specific platelet antigens are called Human Platelet Antigens (HPA).
- If the study is positive, the results allow us to search for compatible donors in order to improve platelet transfusion performance.
Method:
The refractoriness study consists of a set of tests.
In all patients, a screening is performed using Luminex technology to search for anti-HLA class I antibodies and antibodies against the HPA-1, HPA-2, HPA-3, and HPA-5 systems (PakLx Kit).
The genotypes of the HPA systems (HPA-1, HPA-2, HPA-3, HPA-5, and HPA-15) are also studied in all patients. This determination is carried out using Luminex technology (ID CORE XT / ID HPA XT).
When the screening for anti-HLA class I antibodies is positive, the identification of these antibodies is performed using the Luminex Class I Single Antigen Kit.
In patients who are homozygous for the HPA-15 system (15a15a or 15b15b), the presence of alloantibodies against the antigens of this system in the patient's serum is ruled out (using the MAIPA technique).
In patients who are homozygous for the HPA-3 system (3a3a or 3b3b), the study is completed by also ruling out alloantibodies against the HPA-3 system using immunofluorescence.
Diagnostic Algorithm:
When the test 4815 is requested, platelet refractoriness study, the following tests are generated:
| Code | Test Name | Can it be requested separately? | Is it always performed? |
|---|---|---|---|
| 4833 | Anti-HLA class I antibodies | No | Yes |
| 4942 | Anti-platelet antibodies (solid phase) | No | Yes |
| 4818 | Platelet genotype | Yes | Yes |
| 4825 | Platelet crossmatch test (search for compatible donors) | No | No |
| 4809 | Antibodies against HPA-15 system (MAIPA) | Yes | No |
| 4800 | Identification of specific platelet antibodies (IF) | No | No |
Results:
The results of the refractoriness study are:
- Negative study: no antibodies that justify the low transfusion performance are detected.
- Positive study: antibodies that may justify the low transfusion performance have been detected. A search for compatible donors is carried out.
Precautions:
Contact the Immunohematology laboratory to discuss the case, patient diagnosis, clinical situation, transfusion requirements forecast, ABO group, etc...
Response Time:
- 1 working day for the initial screening (HLA class I and HPA-1,2,3, and 5)
- 21 working days for the final report (Genotype, MAIPA, etc...)
Specimen information
Sample: Peripheral blood
Tubes: 1 EDTA of 5 ml + 1 serum
Stability: At room temperature or at 4°C: 3 days
Transport instructions: Preferably at room temperature
Reasons for rejection: Highly hemolyzed sample
Administrative information
BST Code: 4815
Test Description: Platelet Refractoriness Study
Synonyms: Not applicable
Section: Immunohematology
BST Rate: Check the updated rates here.
Profiles:
Test 4815 is included in the Platelet Refractoriness Profile
References
- Kopko PM, Warner P, Kresie L, Pancoska C. Methods for the selection of platelet products for alloimmune-refractory patients. Transfusion. 2015;55(2):235-44.
- Heikal NM, Smock KJ. Laboratory testing for platelet antibodies. Am J Hematol. 2013 Sep;88(9):818-21. doi: 10.1002/ajh.23503. Epub 2013 Jul 23. PMID: 23757218.
- Panch SR, Guo L, Vassallo R. Platelet transfusion refractoriness due to HLA alloimmunization: evolving paradigms in mechanisms and management. Blood Rev. 2023 Nov;62:101135. doi: 10.1016/j.blre.2023.101135. Epub 2023 Oct 2. PMID: 37805287.
- Couvidou A, Rojas-Jiménez G, Dupuis Aand Maître B. Anti-HLA Class I alloantibodies in platelet transfusion refractoriness: From mechanisms and determinants to therapeutic prospects. Front. Immunol. 2023 14:1125367. doi: 10.3389/fimmu.2023.1125367
- Youk HJ, Hwang SH, Oh HB, Ko DH. Evaluation and management of platelet transfusion refractoriness. Blood Res. 2022 Apr 30;57(S1):6-10. doi: 10.5045/br.2022.2021229.