We report bone marrow ablation in a 21-year-old patient with recurrent refractory CD52-positive acute lymphoblastic leukemia, using murine 131I-anti-CD52 monoclonal antibody (mAb) in the conditioning regimen for allogeneic hematopoietic stem cell transplantation. 124I-labeled anti-CD52-mAb PET evaluated radioimmunotherapy (RIT) dosimetry. After myeloablative conditioning, hematopoietic stem cell transplantation from a human leukocyte antigen (HLA)-1-antigen–mismatched, haploidentical family donor was performed. Recurrence 3 months after transplantation led to repeat 124I-alemtuzumab dosimetry, followed by 131I–labeled anti-CD52-mAb RIT (76.8 mCi; effective dose, 0.59 Sv). RIT was well tolerated without toxicity or graft-versus-host disease. Marrow ablation and donor cell engraftment was achieved with conditioning and immunosuppression. Leukemia control was transient. The patient succumbed 2 months after transplantation.
From the *Department of Nuclear Medicine, Innsbruck Medical University, Innsbruck, Austria; and †Division of Hematology and Oncology, Department of Internal Medicine, Innsbruck Medical University, Innsbruck, Austria.
Received for publication June 29, 2011; revision accepted October 18, 2011.
Conflicts of interest and sources of funding: none declared.
Reprints: Daniel Putzer, MD, Department of Nuclear Medicine, Innsbruck Medical University, Anichstraße 35, 6020 Innsbruck, Austria. E-mail: firstname.lastname@example.org.