Virtual platelet cross‐matching as transfusion management for patients with immune platelet refractoriness

Abstract Background and Objectives This study describes the use of the Epvix platform for virtual cross‐matching (VC) of human leucocyte antigen (HLA)‐compatible platelets for patients with immune platelet refractoriness, and demonstrates effectiveness of the selected platelets. Materials and Methods A prospective cohort of haematological patients was evaluated from 2018 to 2022. HLA‐typed donor bank profile was previously uploaded to the Epvix platform. Each patient's antibody reactivity panel (PRA) was included in the platform. Then, search, selection and VC were performed, and 24‐h‐corrected count increment (CCI) platelet transfusion was calculated (reference ≥2500). Results Six patients were included (four female, two male), with mean age of 61 years. HLA antibodies were detected as the cause of immunity for all patients, whereas four patients also had non‐immune causes. High percentage of alloimmunization was detected in all studied patients (mean PRA: 85.7%). Thirty different donors were able to schedule and perform platelet donations. The mean 24‐h CCI count was 9882. All platelet transfusions achieved a satisfactory CCI count except for two transfusion events. Presence of non‐immune causes identified in these two cases could account for the unsatisfactory CCI. Conclusion Epvix is a free application hosted on the Web and uses the HLAMatchmaker algorithm to generate histocompatibility reports. This study demonstrates the efficiency of VC performed by Epvix. However, physical cross‐matching will still be necessary in some instances, as the platform does not support human platelet antigen polymorphism.