Haploidentical Hematopoietic Stem Cell Transplantation to Treat X-linked Lymphoproliferative Syndrome without remission: A Report of 7 cases in a Single Center

Objective: To investigate the prognostic factors of haploid hematopoietic stem cell transplantation in the treatment of X-linked lymphoproliferative syndrome. Methods: Seven children with X-linked lymphoproliferative syndrome diagnosed by XIAP gene analysis were enrolled into our hospital from June 2015 to September 2020. All the children were boys with a median age of 3.1 years (1.2-5.6 years) and a median duration of 9 months (5-28 months) from the disease onset to accepting HSCT. Disease status was assessed before transplantation, with partial remission in 6 cases and disease progression in 1 case. Five children received paternal hematopoietic grafts while two cases experienced secondary transplantations from maternal grafts. Preconditioning regimens consisted of Etoposide (VP-16), Fludarabine (Flu), Busulfan (BU), Anti-thymocyte globulin, but the Busulfan was replaced by Melphalan in the two cases who received secondary transplants. The median count of infused mononuclear cells (MNC) was 9.07×108/kg [(8.45-9.98)×108/kg] and CD34-positive cells was 6.45×106/kg [(4.67-8.53)×106/kg].