Serologic Characteristics and Clinical Significance of Non-ABO Red Blood Cell Antibodies in Hematopoietic Stem Cell Transplant. The BEST Collaborative Study
Recommended Citation
Kogler V, Pagano MB, Fontaine MJ, Azimi V, Brancamp R, Cataife G, Covington M, Delaney M, Eichbaum Q, Jacquot C, Kutner JM, Lu W, Saifee NH, Shan H, Thibodeaux SR, Wali JA, Yeh A, Yokoyama APH, Yunce M, and Ziman A. Serologic Characteristics and Clinical Significance of Non-ABO Red Blood Cell Antibodies in Hematopoietic Stem Cell Transplant. The BEST Collaborative Study. Transplant Cell Ther 2025.
Document Type
Article
Publication Date
9-23-2025
Publication Title
Transplant Cell Ther
Abstract
BACKGROUND: ABO-incompatible hematopoietic stem cell transplant (HSCT) has a number of well-established complications including hemolysis, delayed RBC engraftment, pure red cell aplasia (PRCA), and transfusion dependence. However, the clinical significance of non-ABO RBC antibodies in allogeneic HSCT remains insufficiently explored.
OBJECTIVE: The aim of this study is to characterize the prevalence, incidence, and clinical implications of non-ABO RBC auto- and alloantibodies in the HSCT population.
STUDY DESIGN: This international, multicenter, retrospective study analyzed HSCT 2010-2021 across nine U.S. and one Brazilian academic centers. This study focused on immunohematologic findings in recipients of allogeneic HSCTs, excluding hemoglobinopathies. RBC antibodies were evaluated pre-HSCT and 100 days post-HSCT. Hemolysis was assessed by labs and confirmed by a two-physician review of the medical records. Descriptive statistics and regression analysis were performed. IRB approval and data use agreements were obtained at each center.
RESULT: Study analysis included a total of 8896 transplants. The majority of transplants utilized apheresis collections (78.0%), were matched unrelated (41.6%), involved a non-myeloablative conditioning regimen (51.2%), and were ABO-compatible (56.7%). The prevalence of non-ABO antibodies pre-HSCT, including auto-, alloantibodies, and passive transfer of anti-D, was 4.0% (n=355). The majority of these were alloantibodies (77.5%), followed by warm autoantibodies (7.3%) and both alloantibodies and warm-reactive autoantibodies (6.5%). De-novo antibody formation post-HSCT occurred in 1.5% (n=135). The most frequent pre-HSCT alloantibody specificities were in the Rh blood group system (46%), followed by Kell (17%) and Kidd (13%). The incidence of anti-D in RhD-mismatched transplant was 1% (n=8) for RhD-positive recipients with RhD-negative donors, and 0.2% (n=2) for RhD-negative recipients with RhD-positive donors. Myeloproliferative neoplasms and myelodysplastic syndromes had the highest rate of antibodies pre- and post-HSCT. Hemolysis was observed in 24 cases (antibodies present pre-HSCT) and 15 de-novo cases post-HSCT. Pure red cell aplasia was not observed in any of these cases. The presence of non-ABO RBC antibodies was associated with higher RBC transfusions, but not platelet transfusions; engraftment of neutrophils and platelets were not affected by the presence of RBC antibodies.
CONCLUSION: The current study reports on a low prevalence of RBC antibodies, including allo- and autoantibodies, in HSCT patients during the peri-transplant period, with a rate of 4% for those with pre-existing antibodies prior to transplant and 1% for the de-novo antibody formation post-transplant. They are associated with a low risk of mild to moderate hemolysis, but increased RBC transfusions. Comprehensive immunohematology data should be incorporated into HSCT databases for improved risk assessment, monitoring, and management.
PubMed ID
40998264
ePublication
ePub ahead of print
