Haploidentical haematopoietic stem cell transplantation combined with post-transplant cyclophosphamide in neuronal ceroid lipofuscinosis: Experience in eight patients.

BACKGROUND: Neuronal ceroid lipofuscinoses (NCLs) are rare lysosomal storage disorders characterized by progressive mental retardation and motor developmental regression and myoclonic seizures. Hematopoietic stem cell transplantation (HSCT) has been suggested to be used in the treatment of lysosomal disorders and brain damage caused by a deficiency of soluble lysosomal enzymes. There are no previous reports on treating NCLs with HSCT in China. MATERIAL AND METHOD: NCL pediatric patients who underwent allo-HSCT at Affiliated Children's Hospital of Capital Institute of Pediatrics were involved. A combination of medical histories, clinical features, and genetic analyses was used for the diagnosis of all patients. The written consent form for allo-HSCT was attained from the patient's guardian, which was then reviewed and approved by the ethics committee before the procedure. RESULTS: From January 2018 to May 2019, the haplo-HSCT followed by PT/Cy on eight NCL pediatric patients was performed. The median age was 4.5 years (ranging from 2.8 to 7 years). The donors were their haploidentical HLA-matched parents, as no identically matched donors were found. The median nucleated cell count was 25.37 (10-34.41)×108/kg, and the median CD34+ count was 13.7 (8.95-22)×106/kg. Neutrophil reconstitution occurred 12 days (11-14 days) after transplantation, and the median platelet reconstitution time was 12 days (9-14 days) after transplantation. All patients achieved full donor chimerism and did not develop Grade II-IV acute GvHD or chronic GvHD after transplantation. The median follow-up period was 2.2 (1.5-2.6) years. All patients are still alive at present and develop no severe transplantation-related complications. The mental motor disorders, myoclonic seizures, and vision loss of all patients continued to progress. However, the progression slowed at 12 months after transplantation. CONCLUSION: This study demonstrated that it is safe and efficacious to treat NCLs with haplo-HSCT. Transplantation should be performed at an early stage for the survival quality of pediatric patients.