Department of Pathology, Stanford University School of Medicine, California, United States
Background/Case Studies: Highly sensitized patients, defined as having calculated panel reactive antibody (cPRA) ≥80%, encounter challenges, including increased rejection risk, poorer post-transplant outcomes, and longer waitlist times. Desensitization therapies play a role in expanding transplantation opportunities for these patients. Intraoperative therapeutic plasma exchange (iTPE) represents a potential strategy to mitigate the immunological risk. This study aims to evaluate the clinical outcomes associated with the use of iTPE in highly sensitized heart transplant recipients at a single institution.
Study
Design/Methods: This retrospective, single-center cohort study included 59 adult heart transplant recipients between January 2018 to January 2024. Patients were categorized into three groups for comparison: those receiving iTPE (n=20), sensitized patients without iTPE (n=19), and unsensitized patients (combined cPRA (ccPRA)=0%) (n=20). Human leukocyte antigen (HLA) antibody testing was performed using Luminex single antigen bead assay and patients were surveyed with endomyocardial biopsies. 1-year survival and 1-year freedom from AMR (defined as pathologic AMR grade ≥ 1) were analyzed. Kaplan-Meier method with log-rank test was used for survival analysis and p< 0.05 considered significant.
Results/Findings: Analysis of primary outcomes revealed that the sensitized group had the worst 1-year survival among the groups however, the survival rate did not differ significantly among the groups at 1 year (p= 0.127; Figure 1A). AMR-free survival was lowest in the iTPE group (85%), but the differences among the groups were not statistically significant (p = 0.168; Figure 1B).
Conclusions: Various desensitization strategies exist for managing sensitized transplant recipients. We report that iTPE may serve as an effective adjunct to immunosuppression therapy for these patients to rapidly reduce HLA antibodies before organ placement. iTPE has comparable short-term survival outcomes and potential to shorten the waitlist time. However, further research involving larger, possibly multi-center cohorts is warranted.
