Prospective platelet crossmatching for selection of compatible random donors

Platelet transfusion outcomes can vary due to immune compatibility. Prior research has shown that antibody-mediated reactions may reduce transfusion effectiveness. However, no prior work had resolved how to predict these outcomes reliably. Existing knowledge includes the role of HLA antibodies in platelet refractoriness. This gap motivated the development of predictive testing methods. It was already known that HLA-matched platelets improve outcomes. Yet, routine crossmatching for platelets remains uncommon. The uncertainty around which tests best predict transfusion success remains unresolved. This study addresses the need for a reliable crossmatch technique.

This study aimed to assess whether a specific crossmatch technique could predict platelet transfusion success. The specific problem is the lack of a reliable method to select compatible platelet donors. The motivation stems from the variability in transfusion outcomes. The goal was to compare crossmatch-compatible and incompatible platelet transfusions. The focus was on a 24-hour corrected platelet increment as a success metric. The study sought to validate the predictive value of an indirect platelet antiglobulin test. It aimed to compare this test with an immunofluorescence method. The study's purpose was to guide clinical decisions on donor selection.

The study used an indirect platelet radioactive antiglobulin test in a prospective design. It involved 29 patients who received three types of platelet transfusions. The first group received crossmatch-compatible platelets. The second group received crossmatch-incompatible platelets. The third group received uncrossmatched platelets. A 24-hour corrected platelet increment was measured as the primary outcome. The threshold for success was set at greater than 4.5 × 10⁹/l. The study also compared results with an immunofluorescence technique. The design allowed for direct comparison of transfusion outcomes.

Of 47 predictions, the crossmatch test correctly predicted transfusion outcomes in 90% of cases. Crossmatch-compatible transfusions led to a 17.79 ± 2.01 × 10⁹/l increment. In contrast, incompatible transfusions resulted in only 1.19 ± 0.56 × 10⁹/l. Uncrossmatched transfusions showed a 4.42 ± 0.97 × 10⁹/l increment. The differences were highly statistically significant. The success rate for compatible transfusions was 83% compared to incompatible. The test correlated well with immunofluorescence results. These findings suggest the test is a reliable predictor of transfusion success.

The authors propose that the indirect platelet antiglobulin test is a valid tool for predicting transfusion success. They suggest that crossmatch-compatible platelets significantly improve outcomes. The study supports the use of this test in clinical settings. The results trace directly to the observed increments in platelet counts. The authors do not claim this is the only valid method. They suggest further validation in larger patient groups. The test's 90% predictive accuracy is notable. The authors do not propose this as a replacement for all current methods.