Efficacy Of Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation For 40 Cases With Severe Aplastic Anemia

BackgroudSevere aplastic anemia is an acquired marrow failure syndrome characteri-zed of peripheral pancytopenia and bone marrow hematopoietic dysfunction.Allogenetic hematopoietic stem cell transplantation is the main method to cure SAA.However,due to the implementation of family planning in our country,most families only have one child,the chance of finding a matched sibling donoris less than 30%.While looking for matched unrelated donor in the China hematopoietic stem cell donor database needs a long time,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 the consequence of Haplo-HSCT and MSD HSCT is equivalent,the overall survival is no significant difference.ObjectivesTo investigate the efficacy and prognosis of Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation(Haplo-HSCT)for Severe Aplastic Anemia(SAA).MethodsThe clinical data of 40 SAA cases(29 with SAA-Ⅰ,9 with SAA-Ⅱ,2 wit h posthepatisis SAA)with Haplo-HSCT from September 2013 to February 2018 were retrospectively analyzed.33 SAA patients received peripheral blood he matopoietic stem cells,7 SAA patients combined with bone marrow hematopoi etic stem cells.The conditioning regimen contained cyclophosphamide,fludarab ine and antithymocyte globulin,with or without busulfan or low dose total bo dy irradiation.Cyclosporin-A,short-term methotrexate and mycophenolate mof etil were used for preventing graft versus host disease(GVHD).Results(1)The median counts of mononuclear cell and CD34+stem cell were 5.3(range,2.0-13.5)×10~8/kg and 5.6(range,1.6-15.9)×10~6/kg,respectively.(2)Implantati on:Among 40 SAA cases,hematopoiesis reconstitution was achieved in 36 ca ses(90.0%).The median times for myeloid engraftment and platelet engraftment were 15(range,10-25)days and 17(range,10-58)days,respectively.(3)Acute graf t-versus-host disease:The incidence of acute graft-versus-host disease(aGVHD)was 40.0%(16/40),gradesⅡ-ⅣaGVHD 22.5%(9/40),gradesⅢ-ⅣaGV HD 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 survived at median follow-up time of 353(30-1226)days,the cumulativ e overall survial(OS)was 67.8%±7.8%,and the average time was 883±82 days.Within 100 days after stem cell infusion,transplantation related mortality(TR M)was 12.5%.(5)Univariate analysis show the overall survival is significantly correlation with the disease classification,the count of CD34+stem cell,GV-HD,severe infection,virus infection and fungal infection(P<0.05).Multivari ate logistis analysis show disease classification and severe infection are indepen dent risk factors affecting the overall survival of haploidentical hematopoietic s tem cell transplantation in SAA.Conclusion1.If the immunosuppressive therapy is not effective,and without matched sibling and unrelated donors for severe Aplastic Anemia,Haploidentical Allogeneic Hematopoietic Stem Cell Transplantation is a viable and effective method,which needs to be studied in a large number of cases for enhancing overall survial.2.Severe infection is an independent risk factor affecting the overall surviv al of haploidentical hematopoietic stem cell transplantation in SAA.