Distribution for platelet antibody in patients with immune-mediated platelet transfusion refractoriness

Abstract

Objectives: HLA Class I, HPA (Human platelet antigen), CD36 allo/isoantibodies, and platelet glycoprotein autoantibodies are the primary causes of immune-mediated platelet transfusion refractoriness (iPTR). Detecting these antibodies and selecting antigen-negative platelets for transfusion effectively manages iPTR, but large-scale data on platelet antibody distribution in the Chinese population are scarce.

Methods: From Jan 2021 to Dec 2023, 2073 patients with suspected iPTR underwent platelet cross-matching via solid-phase red blood cell adherence. Sera from those with positive cross-matching (≥1 donor) were analyzed for platelet antibodies using Luminex. Correlations between antibody prevalence, age, gender, and diseases were statistically analyzed.

Results: 621 patients, 30.0% (621/2073) had positive cross-matching with ≥1 donor. Furthermore, 374 (60.2%) patients had platelet antibodies. Moreover, 429 antibodies were detected in these patients, and the constituent ratios of HLA Class I alloantibodies, HPA alloantibodies, autoantibodies (GPIIb/IIIa, etc), and CD36 isoantibodies were 78.09%, 4.65%, 17.01%, and 0.23%, respectively. Abs ranked as follows: HLA Class I > GPIIb/IIIa > GPIa/IIa > HPA-5b, GPIb/IX > HPA-3a > HPA-1b, 2b > HPA-3b, 4b, CD36. Lastly, positive platelet antibodies prevalence correlated with age and sex in leukemia and solid tumor patient groups.

Discussion: This study clarified platelet antibody distribution in Chinese iPTR patients. Besides HLA Class I antibodies, autoantibodies against platelet glycoproteins play a key role. Among HPA antibodies, HPA-5b may predominate in the Chinese population instead of HPA-1a.

Keywords: CD36; HLA; HPA; Platelet transfusion refractoriness; human platelet antibody.