Clinical Study On First-line Treatment Of Severe Aplastic Anemia

Background: Nowadays the first-line therapy for severe aplastic anemia is immunosuppressive therapy(IST)or allogeneic hematopoietic stem cell transplantation(allo-HSCT).Domestic and foreign reports have suggested that immunosuppressive therapy and matched sibling donor hematopoietic stem cell transplantation(MSD-HSCT)for severe aplastic anemia have similar clinical effectiveness and overall survival period.In recent years,unrelated donor transplantation and haploid transplantation have developed rapidly.Studies have shown that the efficacy of unrelated donor transplantation and haploid transplantation as a first-line treatment regimen was similar to MSD-HSCT and superior to IST.There is no consensus on whether unrelated donor transplantation and haploid transplantation can be used as a first-line treatment for SAA patients who lack sibly-compatible donors.Objective: To evaluate the clinical efficacy of immunosuppressive therapy and allogeneic hematopoietic stem cell transplantation for severe aplastic anemia.Methods: Nineteen cases of severe aplastic anemia who had been treated with immunosuppressive therapy(n=7)or allogeneic hematopoietic stem cell transplantation(n=12)from January 2012 to May 2019 were retrospectively analyzed and reviewed.There were 7 patients in the IST group,with a median age of 30(19-67)years.All patients received non-umbilical cord blood on the first day after the end of rATG/pALG.There were 12 patients in allo-HSCT group,with a median age of 38.5(4-49)years,including 7 matched sibling donor transplantation,4 haploidtransplantation and 1 unrelated donor transplantation.Four haploid transplantation patients and two patients older than 40 years in matched sibling donor transplantation were combined with umbilical blood transfusion.Results:(1)Allogeneic hematopoietic stem cell transplantation: Hematopoietic reconstitution was achieved in all patients after transplantation.The median time of neutrophils,platelets and reticulocytes implantation was +10.5(9-18),+15.5(8-39)and+17(11-35)days after transplantation,respectively.Immunosuppressive therapy:Early death occurred in 2 of 7 patients,and treatment was effective in 5 patients.The median time for neutrophil and platelet counts to return to the same level as the transplant were41(9-80)d and 157(61-400)d,respectively.The recovery time of granulocytes and platelets was statistically significant between the two groups(P<0.05).(2)There was no significant difference in response rate at 3 months(allo-HSCT83.3% VS IST57.1%)and complete response rate at 12 months(allo-HSCT50% VS IST28.6%)between the two groups.(3)At the end of follow-up,1 patient was lost to follow-up.The 18 patients who could be followed up had a median follow-up of 21(2.1-91.2)months,and the overall survival rate reached 66.7%.The overall survival rate of the allo-HSCT group was63.6%(MSD-HSCT was 100%,haplo-HSCT was 0%).The overall survival rate of the immunosuppressive treatment group is 71.4%.There is no significant difference between the allo-HSCT group and the IST group,and the MSD-HSCT group and the IST group.Conclusion: Matched sibling donor allogeneic hematopoietic stem cell transplantation is the first choice to cure severe aplastic anemia.Patients older than 40 years old who add third-party cord blood to siblings,which are fast in implantation,have a low incidence of graft versus host disease,and can achieve long-term survival.Unrelated donor transplantation can also be used as a first-line treatment for SAA if highly human leukocyte antigen(HLA)matched donors can be found in the short term.IST should be selected when there is no HLA matched donor,and the effect is better than haploidtransplantation.