Transfusions in Aplastic Anemia Patients Cause HLA Alloimmunization: Comparisons of Current and Past Cohorts Demonstrate Progress

Katja Julen; Thomas Volken; Andreas Holbro; Laura Infanti; Jörg P Halter; Stefan Schaub; Caroline Wehmeier; Tamara Diesch; Alicia Rovó; Jakob R Passweg; Andreas Buser; Beatrice Drexler

doi:10.1016/j.jtct.2021.07.017

Transfusions in Aplastic Anemia Patients Cause HLA Alloimmunization: Comparisons of Current and Past Cohorts Demonstrate Progress

Transplant Cell Ther. 2021 Nov;27(11):939.e1-939.e8. doi: 10.1016/j.jtct.2021.07.017. Epub 2021 Jul 24.

Authors

Affiliations

¹ Blood Transfusion Center, Swiss Red Cross, Basel, Switzerland; Division of Hematology, University Hospital Basel, Switzerland.
² School of Health Professions, Zurich University of Applied Sciences, Winterthur, Switzerland.
³ Division of Hematology, University Hospital Basel, Switzerland.
⁴ Clinic for Transplantation Immunology and Nephrology, University Hospital Basel.
⁵ Division of Hematology /Oncology, University Children's Hospital Basel, Switzerland.
⁶ Division of Hematology, University Hospital Bern, Switzerland.
⁷ Blood Transfusion Center, Swiss Red Cross, Basel, Switzerland; Division of Hematology, University Hospital Basel, Switzerland. Electronic address: Beatrice.drexler@usb.ch.

PMID: 34314891
DOI: 10.1016/j.jtct.2021.07.017

Abstract

Transfusions are the mainstay of supportive therapy in patients with aplastic anemia (AA) and may lead to anti- HLA alloimmunization, thereby also increasing the risk for donor-specific antibodies in the setting of HLA-mismatched transplantation. Historically, AA patients were thought to be at particularly high risk for HLA alloimmunization. In past decades, blood product manufacturing (leukoreduction) and HLA antibody testing have improved significantly by single antigen bead (SAB) technology. It is currently unknown how those developments have impacted HLA alloimmunization and treatment outcome in patients with AA. We retrospectively investigated 54 AA patients treated by immunosuppressive therapy or allogeneic hematopoietic cell transplantation after the introduction of the SAB assay at our center. We compared the HLA antibody results to a historical AA cohort (n = 26), treated before introduction of leukoreduced blood products from 1975 to 1995. HLA alloimmunization was detected in 43 of 54 (80%) recently treated patients. Past pregnancy, female gender, disease severity, age, and a history of other transfusions were significantly associated with a larger number or higher intensity (mean fluorescence intensity) of HLA antibodies. Treatment outcome including bleeding episodes, response to treatment, engraftment, graft-versus-host disease, and overall survival was not associated with HLA alloimmunization. In the historical cohort a significantly higher number of HLA antibodies (P < .01) with a higher mean fluorescent intensity (P < .01) was observed. HLA alloimmunization remains frequent in AA tested by current techniques, but it has significantly decreased since prior decades and does not affect treatment outcome. © 2021 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.

Keywords: HLA alloimmunization; HLA antibodies; aplastic anemia.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Anemia, Aplastic* / therapy
Female
Graft vs Host Disease*
HLA Antigens
Histocompatibility Testing
Humans
Retrospective Studies

Substances

HLA Antigens