PRA is Not Associated with Rejection in Combined Heart and Liver Transplantation

Abstract

Combined heart liver transplantation (CHLT) is relatively rare with approximately 250 cases from 1988-2018 nationally, but with rising numbers each year due to excellent survival. CHLT outcomes have potential immunological benefits compared to heart transplant alone. Liver allografts have long been observed to be more tolerant to HLA mismatch while showing some degree of immune protection in combined organ transplantation. A retrospective analysis from our center's experience of CHLT was performed. Outcomes of patients who had pre-transplant elevated panel reactive antibodies (PRA) >50-99% were compared to those with 0% and those with a low to moderate PRA (1-50%). The hypothesis was tested with the Fisher's exact test. Between 1997 and 2019, 37 patients underwent CHLT. The average age was 42.4 years +/- 10 with 8 deaths (21.6%) ranging from day 2 to 4.5 years post-transplant (5, 13.5% within the first year). None of the deaths were due to rejection or primary graft dysfunction. There were no episodes of humoral rejection and there were 2 episodes (5.4%) of cellular rejection in hearts and 4 (10.8%) in livers (of these, one episode was dual organ rejection). There was no statistical significance at baseline between PRA and history of Fontan physiology, protein losing enteropathy, prior sternotomy, diabetes, hypertension or renal disease. Furthermore, there was no correlation between PRA and death, rejection of either organ, presence of donor specific antibodies, ejection fraction below 50% (1 month and 1 year), length of stay over 30 days, post-transplant hypertension, diabetes or renal disease (table 1). The degree of allosensitization was not associated with worse outcomes in the CHLT population. While the sample is small, it is a reassuring finding that may change the perception of risk when planning a CHLT in a highly sensitized patient.