Mismatched HLA loss is a cause of leukemia relapse after HLA-haploidentical stem cell transplantation (haplo-SCT). We report a patient with a history of 2 occurrences of leukemia relapse due to mismatched HLA loss after haplo-SCT. He received haplo-SCT from his father but showed leukemia relapse with loss of the maternal HLA haplotype. He then underwent haplo-SCT from his mother, and developed relapse with loss of the paternal HLA haplotype. Both donors had killer cell immunoglobulin–like receptor-ligand mismatch but alloreactive natural killer cells could not prevent relapse. Second haplo-SCT should be conducted carefully for patients with relapse due to mismatched HLA loss.
*Department of Pediatric Oncology, Fukushima Medical University Hospital
†Department of Blood Transfusion and Transplantation Immunology, Fukushima Medical University, Fukushima, Japan
Presented previously at the 35th annual meeting of the Japan Society for Hematopoietic Cell Transplantation.
The authors declare no conflict of interest.
Reprints: Hideki Sano, MD, PhD, Department of Pediatric Oncology, Fukushima Medical University Hospital, 1 Hikarigaoka, Fukushima City, Fukushima 960-1295, Japan (e-mail: firstname.lastname@example.org).
Received June 2, 2018
Accepted January 14, 2019