[The Clinical Efficacy of Haploidentical Hematopoietic Stem Cell Transplantation by Using Parental Donors in Patients with Thalassemia].

Objective: To analyze the clinical efficacy of haploidentical hematopoietic stem cell transplantation (haplo-HSCT) by using parental donors on thalassemia patients.

Methods: The 13 thalassemia patients treated by haplo-HSCT using parental donors in our hospital from July 1, 2016, to July 1, 2020 were retrospectively reviewed. Hematopoiesis reconstitution, the incidence of GVHD, infections and the long-term survival of the patients were analyzed.

Results: Twelve of the 13 patients were successfully implanted, the success rate of implantation was 92.3%. The median time of neutrophil and platelet engraftment was 12.5 days (range, 9-22 days) and 21 days (range,12-34 days), respectively. One patient achieved primary graft failure. Three (25%) patients developed to acute GVHD (aGVHD) and achieved complete remission after treatment. Chronic GVHD developed in three (25%) patients, one of them was extensive and under treatment, while one patient developed to severe bacterial infection (7.7%). CMV viremia was diagnosed in two patients (15.4%). There were no patients developed to CMV disease. Three (23.1%) patients achieved EB viremia after transplantation, one of them developed to EBV-related lymphocytic proliferative disease, while there were no patients showed invasive fungal infection. At the last follow-up, all patients survived, twelve of them were free from transfusion dependency. There were no transplant-related deaths. Projected overall and thalassemia-free survival at three years was 100% and 92.3%, respectively.

Conclusion: The transplant protocol of haplo-HSCT by using parental donors in patients with thalassemia has reliable source of donors, high incidence of successful implantation and low incidence of GVHD, which can be used as an effective way to increase the source of donors in children with thalassemia.