Three patients highlighting potential pitfalls in platelet refractory testing.
Transfusion
; 63(4): 888-892, 2023 04.
Article
en En
| MEDLINE
| ID: mdl-36794568
ABSTRACT
BACKGROUND:
Platelet-transfusion refractory (PR) patients do not achieve expected post-transfusion platelet counts. We investigate suspected PR patients with post-transfusion platelet counts, indirect platelet antibody screens (ind-PAS), Class I HLA antibody tests (HLA-Scr), and physical platelet crossmatch (PXM) studies. STUDY DESIGN ANDMETHODS:
The three following cases describe possible pitfalls of laboratory tests used in PR workup and management.RESULTS:
Case #1 Antibody testing detected antibodies to only HLA-B13, corresponding to a 4% calculated panel reactive antibodies (CPRA; 96% predicted donor compatibility). However, PXM showed the patient compatible with 11/14 (79%) donors; two of the PXM-incompatible units were ABO-incompatible. Case #2 PXM revealed compatibility with 1/14 screened donors; however, the patient did not respond to the product from the compatible donor. The patient did respond to HLA-matched product. Dilution studies provided evidence of the prozone effect, which caused negative PXM despite clinically relevant antibodies. Case #3 There was a discrepancy between the ind-PAS and HLA-Scr. Ind-PAS was negative for HLA antibodies, while HLA-Scr was positive and specificity testing corresponded to 38% CPRA. Per the package insert, the sensitivity of ind-PAS is ~85% compared to HLA-Scr.DISCUSSION:
These cases highlight the importance of investigating incongruent results. Cases #1 and #2 demonstrate PXM pitfalls ABO incompatibility can result in positive PXM and false-negative PXM can occur in the setting of the prozone effect. Case #3 reveals the importance of knowing a test's sensitivity. Centers that only perform ind-PAS may fail to detect HLA antibodies.Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plaquetas
/
Tipificación y Pruebas Cruzadas Sanguíneas
/
Transfusión de Plaquetas
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Transfusion
Año:
2023
Tipo del documento:
Article
País de afiliación:
Estados Unidos