Outcomes of T-Cell Depleted Haploidentical Peripheral Blood Stem Cell Transplantation for Adult Acute Leukemia: A Meta-Analysis

Abstract Background: Ex-vivo T-cell-depleted graft is used to prevent acute and chronic GVHD for haploidentical hematopoietic SCT (HSCT). We conducted a systematic review and meta-analysis to evaluate the outcomes of T-cell-depleted grafts for peripheral blood haploidentical stem cell transplantation in patients with acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Method: A comprehensive literature search on PubMed, Embase, Cochrane and Web of Science was conducted up to July 25, 2018. Two independent reviewers screened the literature and extracted data. The methodological quality was assessed using modified Newcastle-Ottawa Scale. CMA software v.3 was used for the analysis. Heterogeneity among studies was assessed using the I2 test. Random-effect model was applied. Results: The search strategy identified over 550 articles; three studies (n = 404 patients; 1 prospective; 1 multi-center) were selected for this meta-analysis. The sample size of the studies varied between 34 and 266 patients. The median follow-up ranged from 6 to 47 months. Two studies (Aversa, F. et al. 2005)(n=104 patients); (Ciceri, F. et al. 2008)(n=266 patients) used CD34+ selected cells and other study used TCR-αβ depleted PBSC graft (Kaynar, L. et al. 2016) (n=34). All studies used myeloablative (MA) conditioning. In vivo T-cell-depletion by ATG was used in two studies. Two studies using mega-dose of CD34+ did not use GVHD prophylaxis and other study with αβ T-cell depleted graft used mycophenolate mofetil (MMF). Engraftment rates ranged from 91% to 98%. Pooled rates (95%CI) of grade II-IV, III-IV aGVHD and chronic GVHD were 9% (4-20; I2=82%), 4.8% (1.7-13.1; I2=78%) and 10.7% (6.3-17.6; I2=64%), respectively. The pooled estimates (95%CI) showed a 2-year disease-free survival (DFS) rate of 30.8% (24.2-38.3; I2=54%), 2-year relapse incidence of 21.5% (17.4-26.2; I2=85%). The results are shown in figure 1. Conclusion: T-cell-depleted peripheral blood stem cell graft for haploidentical transplantation in acute leukemia may be an alternative treatment option. Larger prospective studies are needed to evaluate the outcomes of different manipulation techniques. Disclosures No relevant conflicts of interest to declare.