PS1553 EFFICACY OF HAPLOIDENTICAL ALLOGENEIC HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR 40 CASES WITH SEVERE APLASTIC ANEMIA

Abstract

Background:Severe aplastic anemia is an acquired marrow failfure syndrome. Allogenetic hematopoietic stem cell transplantation is the main method to cure SAA. But the chance of finding a matched sibling donor of human leukocyte antigen is less than 30%. While looking for matched unrelated donor in the China hematopoietic stem cell donor database is in a longer period,with low probability and the donor is easy to regret, which may delay the transplantation time.At present, haploidentical hematopoietic stem cell transplantation with SAA has matured,the donor is readily available,parents and compatriots are with good compliance. And a number of studies have shown that Haplo‐HSCT treatment of SAA and MSD‐HSCT treatment of SAA is equivalent,overall survival is no significant difference.Aims:To investigate the efficacy and prognosis of Haplo‐HSCT for SAA.Methods:The clinical data of 40 SAA cases with Haplo‐HSCT from September 2013 to December 2017 were retrospectively analyzed. 33 SAA patients received peripheral blood hematopoietic stem cells,7 SAA patients combined with bone marrow hematopoietic stem cells. The conditioning regimen contained cyclophosphamide,fludarabine and antithymocyte globulin,with or without busulfan or low dose total body irradiation. Cyclosporin A,short term methylaminopterin and mycophenolate mofetil were used for preventing graft versus host disease(GVHD).Results:(1) Of 40 cases with Severe Aplastic Anemia which have undertook Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation,the median counts of mononuclear cell and CD34+ stem cell were 5.3(range,2.0–13.5) × 108/kg and 5.6(range,1.6–15.9) × 106/kg,respectively. (2) Implantation:Among 40 SAA cases,hematopoiesis reconstitution was achieved in 36 cases(90.0%). The median times for myeloid engraftment and platelet engraftment were 15(range,10–25) and 17(range,10–58)days,respectively. (3) Acute graft‐versus‐host disease:The incidence of acute graft‐versus‐host disease(aGVHD) was 40.0% (16/40), grades II‐IV aGVHD 22.5% (9/40), grades III‐IV aGVHD 15.0% (6/40). The incidence of Chronic GVHD(cGVHD) was 25.0% (10/40),extensive cGVHD 12.5% (5/40). (4) Clinical efficacy:26 (70.0%) SAA cases alived at median follow‐up time of 353 (30–1226) days,the cumulative overall survial(OS) was 67.8% ± 7.8,and the average time was 826 ± 85days. Within 100 days after stem cell infusion,transplantation‐related death(TRM) within 100 days was 12.5%. (5)Univariate analysis show the overall survival is significantly correlation with the disease classification, the count of CD34+ stem cell, with or without GVHD,with or without severe infection, with or without virus infection, with or without fungal infection (P<0.05). Multivariate logistis analysis show disease classification and severe infection is an independent risk factor affecting the overall survival of haploidentical hematopoietic stem cell transplantation in SAA.Summary/Conclusion:1.If the immunosuppressive therapy is not effective,and without matched sibling and unrelated donors for severe Aplastic Anemia,Haplo‐HSCT is a viable and effective method,which needs to be studied in a large number of cases for enhancing overall survial.2.In Haplo‐HSCT,it is important to reduce the risk of infection caused by various factors as far as possible. For the existing infection,timely anti‐infective treatment is necessary to delay its further development.