Low-dose ATG combined with low-dose PTCY in preventing GVHD after haploidentical transplantation: a retrospective analysis of 90 cases

Objective To retrospectively analyze the efficacy and safety of low-dose antithymocyte globulin (ATG) combined with low-dose post transplantation cyclophosphamide (PTCY) in prevention of graft versus host disease (GVHD) after haploidentical transplantation. Methods Clinical data of 90 patients receiving haplotype matched transplantation in No.920 Hospital of PLA Joint Logistic Support Force from January 2022 to February 2023 were collected, and they were divided into study group (n=47) and control group (n=43) according to different GVHD prevention programs.The patients of the study group were given low-dose ATG combined with low-dose PTCY, and those of the control group received standard dose of PTCY.The implantation status, occurrence of GVHD, survival status and other indicators were analyzed between the 2 groups. Results ① Both groups of patients were successfully implanted, the median duration for neutrophil implantation (11 vs 17 d, P < 0.05) and platelet implantation (12 vs 20 d, P < 0.05) was significantly shorter in the study group than the control group.The incidence of grade Ⅱ~Ⅳ aGVHD (12.8%vs 34.9%, P < 0.05) and grade Ⅲ~Ⅳ aGVHD (6.4%vs 20.9%, P < 0.05) was significantly lower in the study group than the control group, so was the non-recurrent mortality rate (6.4%vs 20.9%, P < 0.05) and the incidence of hemorrhagic cystitis (12.8%vs 34.9%, P < 0.05).② By the end of the study, there were no significant differences in the incidence of mild and moderate and severe cGVHD, recurrence rate, reactivation rates of EBV and CMV, overall survival rate or progression-free survival rate between the 2 groups. Conclusion For haploidentical transplantation, low-dose ATG combined with low-dose PTCY has the advantages of lower incidence of GVHD, non-recurrent mortality, incidence of hemorrhagic cystitis and faster implantation.