Restrictive Transfusions in the Era of Pathogen-Inactivated Platelets: A Single Center Experience

Introduction Blood managementand infectious disease mitigation are essential for success with allogeneic stem cell transplant (alloSCT). We sought to investigate the safety profile of a proactive infection mitigation strategy with the use of pathogen-inactivated (PI) platelets (PLT) during the alloSCT peri-engraftment period in the era of restrictive blood transfusion. Methods We retrospectively analyzed data from patients undergoing alloSCT that received prophylactic red blood cell (RBC) and PLT transfusion triggered by a hemoglobin of 8 g/dL and PLT count of 15,000 PLT/mL. When available, PI PLT (non-irradiated) were used starting November 2016 until March 2018 (study timeframe). Statistical analysis was performed using SAS 9.4 (Cary, NC). Patients characteristics and clinical parameters were summarized using mean and standard deviation or median and range for continuous data, and frequency and percentage for categorical data. Kaplan-Meier analysis was used to estimate progression-free survival (PFS) and overall survival (OS) from day of transplant. A two-sided logrank test was used to compare across strata using p Results Sixty-eight patients received alloSCT. Median age at transplant was 55 years (range [R], 18-73). Peripheral blood stem cells were the graft source in all but one patient. Donor source was a matched related, 10/10 matched unrelated (MUD), 9/10 MUD and haploidentical donor in 30.9%, 44.1%, 2.9%, and 22.1% of cases, respectively. Myeloablative conditioning was used in 45.6% of patients. Indication for alloSCT was a myeloid or lymphoid disorder in 64.7% and 35.3% of cases. Median time to neutrophil and PLT engraftment was 12 (R, 10-35) and 12 days (R, 8-120), respectively. Pre-alloSCT RBC alloimmunizationwas present in 11.8% of patients. Cumulative incidence of grades II-IV acute and chronic graft-versus-host disease (GVHD) was 20.6% and 22.1%, respectively. PI PLT were used in 73.5 % patients. There were no cases of transfusion associated graft failure (GF) or GVHD. Bacteremia occurred in 10.0% and 22.1% of patients by 30 days and 100 days post-alloSCT, respectively, and were both associated with worse OS (both p Conclusions Restrictive prophylactic transfusion thresholds in alloSCT recipients is feasible. Limited PI PLT transfusion was not associated with transfusion-attributable GVHD, GF or infectious complications. Future prospective studies should determine the short term hemostatic efficacy and long term post-alloSCT outcomes with restrictive transfusion criteria in an era of expanding PI product use.