[Practical Application of Gene-Matched Platelets in Patients with Immune Platelet Transfusion Refractoriness]

To develop a personalized platelet transfusion strategy based on platelet genotyping, donor-specific antibody (DSA) avoidance, and donor-recipient cross-reactive group (CREG) compatibility grading for patients with immune platelet transfusion refractoriness (PTR).

HLA-A and HLA-B genotypes of both recipients and donors were determined using quantitative real-time PCR. Platelet-reactive antibody specificities were characterized by the Luminex xMAP^® single-antigen beads. The probability of obtaining a genotypically matched platelet unit was estimated from regional HLA-I antigen frequencies, antibody specificity profiles, and CREG compatibility grading. Transfusion efficacy was prospectively monitored using the 24-hour corrected count increment (CCI).

A total of 45 HLA-I antibodies were detected in the recipients, and 25 of them had a random mismatch probability of more than 1%. After DSA avoidance, 80.5% of the matches between the recipients and donors in the local platelet database achieved a CREG compatibility level of B2UX or above. The 24-hour CCI of 20 platelet genotyping transfusions was (18.71±9.99), and the platelet transfusion interval was (11.60 ± 9.96) d. Although the recipients were negative for HLA-A24 antibody, the 24-hour CCI of 3 transfusions was <4.5. Notably, 25% of serologically negative samples tested positive for HLA-I antibodies by confirmatory testing.

A transfusion strategy combining DSA avoidance and CREG-compatible donor selection significantly improves platelet transfusion efficacy. Establishing individualized genotyping archives and implementing serial CCI surveillance help identify underlying causes of refractoriness, including HLA-incompatible alleles that are undetectable by routine DSA screening.