RESUMO
Objective: To investigate the safety and efficacy of haploidentical hematopoietic stem cell transplantation with different intensity conditioning regimen in the treatment of childhood aplastic anemia (AA) . Methods: Thirty-seven AA patients who underwent haploidentical transplantation in BaYi Children's Hospital Affiliated to PLA Army General Hospital from January 2013 to January 2017 were enrolled. According to the dosage of conditioning regimen, 34 patients excluding 3 other conditioning regimens were divided into high-dosage group (regimen 2, 22 cases) and low-dosage group (regimen 3, 12 cases). The data of Engraftment, graft-vs-host disease (GVHD), hematopoietic reconstitution, relapse, infection, overall survival (OS) were analyzed. The comparison between the two groups was tested by χ(2) test. Results: A total of 35 of 37 patients achieved primary engraftment; 2 cases died of regimen-related toxicity and severe infection before the infusing of the grafts. The activation rate of CMV and EBV was 60% (21/35) . Post-transplant lymphocyte disease (PTLD) of lung occurred in one case. The cumulative incidences of acute GVHD grade â -â £ and chronic GVHD were 29% (10/35) and 34% (12/35) respectively and the incidence of extensive chronic GVHD was 6% (2/35) . The median follow-up time was 18.8 (2.9-44.1) months, the OS was 92% (34/37) .All survived patients were no longer dependent on blood transfusion and none of them had recurrence. Comparing the rates of overall survival(86%(19/22) vs.100%(12/12)) and rates of chronic GVHD(40%(8/20) vs. 17%(2/12)) in regimen 2 and regimen 3 group, there were no significant difference (χ(2)=1.742, 1.841, all P>0.05) . Significant difference was found at the incidence of â -â £ acute GVHD (10% (2/20) vs. 50% (6/12) ,χ(2)=6.200, P=0.013). Conclusions: Haploidentical hematopoietic stem cell transplantation is effective and safe. It is suitable for patients who are not eligible for matched donor transplantation. Application of reduced dose preconditioning in haploid transplantation is worth exploring.