Platelet antibody screening for preventing post-transfusion platelet refractoriness: a systematic review and...

Post-transfusion platelet refractoriness (PTR) is a major complication in transfusion medicine. While non-immune factors are the most common cause, immune-mediated PTR, often caused by alloimmunization against human leukocyte antigens (HLA), leads to ineffective platelet transfusions, increased bleeding risks, and poorer outcomes in patients with hematologic malignancies or undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT).

To assess the effectiveness of platelet antibody screening, particularly anti-HLA antibody detection using mean fluorescence intensity (MFI) thresholds, in reducing the incidence of immune-mediated PTR and improving transfusion-related outcomes.

This systematic review and meta-analysis, conducted in accordance with PRISMA guidelines, involved a comprehensive search of databases including PubMed, Embase, Cochrane Library, Scopus, and Web of Science. The outcomes include post-transfusion PTR incidence, survival rates, and transfusion-related complications. To assess the effectiveness of platelet antibody screening, relative risks (RRs) and odds ratios (ORs) were calculated, with further subgroup analyses performed based on mean fluorescence intensity (MFI) thresholds, patient populations, and screening methodologies.

The final analysis included seven retrospective cohort and case-control studies, encompassing a total of 2865 patients. Patients who underwent antibody screening had a significantly lower PTR incidence (15.4 %, 95 % CI: 12.1-18.7 %) compared to unscreened patients (28.6 %, 95 % CI: 23.7-33.5 %), reflecting a 46 % reduced risk (RR: 0.54, 95 % CI: 0.41-0.71). High MFI thresholds (>10,000) showed stronger specificity for predicting PTR, while lower thresholds (>5000) demonstrated greater sensitivity. Secondary outcomes included reduced mortality, improved engraftment, and fewer transfusion-related complications in patients identified via screening who subsequently received compatible transfusions.

Platelet antibody screening is an effective strategy for identifying patients at risk for immune-mediated PTR. This screening enables the implementation of targeted transfusion protocols (e.g., HLA-matched platelets), which mitigate PTR and improve clinical outcomes, particularly in high-risk populations. Standardizing MFI thresholds and protocols is essential for broader clinical application. Further prospective research is needed to validate these findings and assess cost-effectiveness.