Identification of Anti-HLA-C Autoantibody As Risk Factor for Primary Platelet Transfusion Refractoriness in Patients with Hematologic Disorders

• Published in: Blood 2023-11, Vol.142 (Supplement 1), p.4035-4035
• Main Authors: Li, Xunhua, Hu, Tonglin, Liu, Qi, Dong, Jingjie, Guo, Junfeng, Hong, Yaonan, Shen, Yingying, Shen, Yiping, Shen, Jianping, Zhou, Yuhong, Ye, Baodong, Wu, Dijiong
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2023-186675

Platelet transfusion is an important supporting treatment for hematologic disorders, especially in bone marrow failure disease and post-chemotherapy myelosuppression. However, in patients experienced multiple transfusions, platelet transfusion refractoriness (PTR) occasionally happened. Up to date, many factors had been explored contribute to the PTR, including infections, splenomegaly, antibodies against human leukocyte antigen class I (HLA-I) and antibodies against human platelet antigens (HPA). Based on our clinical practice, we also discovered that many cases had experienced primary PTR (who have been experienced PTR since the first platelet transfusion). Those patients suffered from severe thrombocytopenia can only be effectively corrected by cross-matching platelet transfusion. To our knowledge, anti-HLA-I-A and B antibodies had been reported to be in reference to immune-mediated PTR, while there are no conclusions about primary PTR. Herein, we identified anti-HLA-C autoantibodies was an independent risk factor for the primary PTR in patients with hematologic disorders, even refractoriness to cross-matching platelet transfusion or HLA-selected platelet transfusion. We retrospectively reviewed the patients that had HLA high resolution genotyping test report (potential for hematopoietic stem cell transplantation), and along with a donor-specific HLA antibodies (DSA) test or PRA testing potential for cross-matching platelet transfusion in our department between January 2019 and March 2023. 114 patients were enrolled, with a median age of 40 (14-80) years old, and the composition of disorders were aplastic anemia (65.8%), leukemia (21.9%), myelodysplastic syndrome (8.8%) and other (3.5%) (Fig A). Post-transfusion platelet efficacy was evaluated by the calculation of corrected count increment (CCI). The overall transfusion effective rate was 69.23% in this cohort, while 18.8% failed response from the first transfusion. Logistic regression analysis showed that only anti-HLA-I antibody contribute to the ineffectiveness of first and overall platelet transfusion (Fig B-E). In patients with positive anti-HLA-I antibodies, there were 35, 48 and 32 patients positive for anti-HLA-A, B and C antibodies, respectively (Fig A). Meanwhile, we surprisingly found that there were also 6 patients have anti-HLA-I autoantibody, including 6 on HLA-C and 1 have both HLA-A and C. To distinguish and gain a better understanding of the value of anti-HLA autoantibody in both TR an