Haploidentical Hematopoietic Stem Cell Transplantation for Malignant Infantile Osteopetrosis and Intermediate Osteopetrosis:A Retrospective Analysis of a Single-Center

Abstract

ObjectiveTo evaluate the clinical efficacy of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) for treatment of malignant infantile osteopetrosis (MIOP) and intermediate osteopetrosis.MethodsChildren with MIOP and IOP who underwent haplo-HSCT in Beijing Children’s Hospital, Capital Medical University, from January 2010 to May 2018 were retrospectively analyzed. Data relating to the clinical manifestations, engraftment, and prognosis of the children were extracted from medical records. ResultsTwenty-seven patients, including 18 males and 9 females, with an onset age of 12 (0.04-72) months, were enrolled in this study. The median time from diagnosis to transplantation was 4 (1-23) months. All patients received haplo-HSCT with myeloablative conditioning regimen (including fludarabine, busulfan, and cyclophosphamide). The graft versus host disease (GVHD) prophylaxis was based on anti-human T lymphocyte porcine immunoglobulin /anti-human thymus globulin, methotrexate, and mycophenolate mofetil. The median observation time was 55.2 (0.3-126.2) months. By the end of follow-up, twenty patients survived and seven patients died. The five years overall survival rate was 73.9%. Acute GVHD degree I-II was observed in 20 patients, degree III in 1 patient and without degree IV. Chronic GVHD was observed in 11 patients (40.7%). It was controlled by anti-GVHD therapy.ConclusionHaplo-HSCT was effective for MIOP and IOP, with high survival rate and significantly improved of clinical symptoms. For the patients with vision impairment before HSCT, the improvement was slow after transplantation. The incidence of GVHD was high but mild, and could be effectively controlled after appropriate treatment. These data provided that haplo-HSCT was feasible in the treatment of MIOP and IOP.