PB2188: APPLICATION PROSPECT OF LOW DOSE PORCINE ANTITHYMOCYTE GLOBULIN IN HLA MATCHED SIBLING DONOR TRANSPLANTATION

Abstract

Background: To investigate the preventive effect of low-dose porcine antithymocyte globulin (P-ATG) on graft versus host disease (GVHD) in HLA matched sibling donor transplantation. Aims: To investigate the preventive effect of low-dose porcine antithymocyte globulin (P-ATG) on graft versus host disease (GVHD) in HLA matched sibling donor transplantation. Methods: The clinical data of 60 patients with hematological malignancies who received MSD-HSCT from July 2020 to October 2021 were analyzed retrospectively. These patients / donors were older than 40 years old or the donors were female. Of these, 30 patients received Low-dose porcine ATG as a part of conditioning regimen (P-ATG group), while the other 30 patients didn’t receive ATG (No-ATG group). In addition to the fact that the ages of the patients and donor were older in P-ATG group, all patients’ other baseline characteristics and donor condition of the two groups were similar. Results: All patients engrafted in two groups. There were significant differences in the incidence of aGVHD ([23.3 (10.1-39.7)%] vs [50.0 (30.8-66.5)%], P = 0.0276), grade III-IV aGVHD ([16.7 (5.94-32.1)%] vs [40.0 (22.4-57.0)%], P = 0.0491) and cGVHD ([22.4 (6.03-45.1)%] vs [69.0 (43.4-84.8)%], P = 0.0009) between the P-ATG and No-ATG groups. But there was no significant difference in terms of 1-year OS ([79.9 (60.5-90.4)%] vs [84.0 (61.2-94.0)%], P = 0.4411) or RR ([13.6 (2.73-33.2)%] vs [15.2 (4.40-32.1)%], P = 0.7416). And there was also no significant difference with regard to the incidence of severe bacterial infection (P = 0.612), invasive fungal disease (P = 1.000) or CMV infection (P = 0.2976). 80% (4 / 5) of patients in P-ATG group died of secondary infection after grade III-IV aGVHD, and 16.7% (2 / 12) in No-ATG group. Summary/Conclusion: The application of low-dose P-ATG in the conditioning regimen of MSD-HSCT can significantly reduce the incidence of aGVHD, grade III-IV aGVHD and cGVHD, doesn’t increase the risk of recurrence after transplantation in patients / donors older than 40 years old or female donors. However, the patients in P-ATG group were older and had high mortality caused by secondary infection after grade III-IV aGVHD. Therefore, there was no significant difference in OS between the two groups.