P823: THE INCIDENCE, OUTCOMES, AND RISK FACTORS OF SECONDARY POOR GRAFT FUNCTION IN HAPLOIDENTICAL HEMATOPOIETIC STEM CELL TRANSPLANTATION FOR ACQUIRED APLASTIC ANEMIA

Abstract

Background: Secondary poor graft function (sPGF) increases the risk of life-threatening complications after transplantation and is an obstacle to achieving better outcomes after hematopoietic stem cell transplantation (HSCT). Aims: We aimed to determine the incidence, clinical outcomes, and risk factors of sPGF in haploidentical HSCT (haplo-HSCT) for acquired aplastic anemia (AA) patients. Methods: We retrospectively reviewed 430 consecutive AA patients receiving haplo-HSCT in Peking University People’s Hospital between January 2006 and December 2020. Results: We reported the estimated 3-year cumulative incidence of sPGF was 4.64%, while no primary PGF occurred. The median time to sPGF was 121 days (range 30-626 days) after transplantation. To clarify the risk factors for sPGF, 17 sPGF cases and 382 without PGF were further analyzed. Compared to patients without PGF, the 2-year overall survival was significantly poorer for sPGF patients (67.7% vs 90.8%, p =.002). Twelve sPGF patients were alive until the last follow-up, and 7 achieved transfusion independency. The multivariable analyses revealed that a history of refractory cytomegalovirus viremia (CMViremia) (OR=7.038, p=.002) post-transplantation independently increased the risk of sPGF. There was weak evidence that a history of grade 3-4 acute graft-versus-host disease (aGvHD) increased the risk of sPGF (p=.092). Summary/Conclusion: In conclusion, sPGF can develop in 4.64% of AA patients after haplo-HSCT and significantly decreases survival. The independent hazard elements for sPGF were a history of refractory CMViremia and grade 3-4 aGvHD. We advocated better post-transplantation strategies to balance the risk of immunosuppression and viral reactivation for haplo-HSCT in AA patients.