Effect of ABO Mismatch and Red Blood Cell Alloimmunization on the Outcome of Hematopoietic Cell Transplantation for Sickle Cell Disease

• Published in: Transplantation and cellular therapy 2024-11
• Main Authors: Saib, Israa, Alahmari, Bader, Alsadi, Husam, Alaskar, Ahmed, Hejazi, Ayman, Salama, Hind, Al Raiza, Abdulrahman, Saleh, Abdullah S. Al, Ibrahim, Ayman, Bakkar, Mohammed, Ghori, Abdulrauf, Alsuhaibani, Ahmed, Alharbi, Ahmed, Alanazi, Tahani, Ahmed, Rasha, Shehabeddine, Inaam, Alkhraisat, Suha, Alharbi, Amani, Mahasneh, Isam, Ballili, Maybelle, Aljubour, Zied, Ahmed, Mazen, Alzahrani, Mohsen
• Format: Article
• Language: English
• Subjects: Alloimmunization; Hematopoietic stem cell transplantation; RBC group mismatch; Sickle cell disease
• ISSN: 2666-6367; 2666-6367
• DOI: 10.1016/j.jtct.2024.11.003

•The presence of donor-specific RBC alloantibodies is an independent risk factor for graft failure (GF).•Patients with GF have inferior survival, and strategies to decrease GF are needed.•Selection of best HCT donors should include ABO matching and no alloimmunization. Hematopoietic stem cell transplantation (HCT) remains the sole well-established curative option for patients with sickle cell disease (SCD). Nonmyeloablative conditioning has been used to improve outcomes and reduce toxicities in adult SCD patients. However, recipient-donor ABO incompatibility and alloimmunization may be significant impediments to successful outcomes of HSCT in SCD patients owing to risks of hemolysis, delayed engraftment, poor graft function, and graft failure (GF). Here we report our experience with allogeneic HCT for SCD and the effects of RBC group mismatch and alloimmunization on the outcome of transplant recipients. We conducted a retrospective analysis of all SCD patients age >14 years who underwent HCT between January 2015 and February 2022 at our center. All patients received i.v. alemtuzumab (1 mg/kg divided over 5 days on days -7 to -3) and 300 cGy total body irradiation on day -2 or -1 for conditioning. Pretransplantation preparation consisted of hydroxyurea at the maximum tolerated dose for 2 to 3 months and 1 session of exchange transfusion. Peripherally mobilized CD34 stem cells targeting 10 × 106 /kg of recipient weight were used. For graft-versus-host disease prophylaxis, sirolimus was started on day -1 and continued for 1 year with tapering if lymphoid chimerism was >50%. For patients with major ABO incompatibility, we administered 2 doses of rituximab (375 mg/m2) and 3 sessions of plasmapheresis before starting the conditioning regimen, targeting an isohemagglutinin titer