Porcine Kidney Xenotransplantation in Patients With End-Stage Kidney Disease
brief summary
The mismatch between organ supply and demand results in the deaths of thousands of Americans each year. Our research group aims to solve this unmitigated health care crisis by translating advances in xenotransplantation to humans and expanding organ supply in a sustainable fashion using genetically modified pigs as a source of organs. We propose here a phase I clinical trial of porcine kidney xenotransplantation into 20 people with end-stage kidney disease. Source donor animals are pigs with 10 gene edits (10-GE) which attenuate immunologic harm to the kidney xenograft. 10-GE pigs are housed in a designated pathogen-free facility within 30 minutes of the transplantation center. Xenotransplantation procedures follow conventional practices currently employed in allotransplantation and comply with multiple regulatory standards to ensure ethical treatment of research subjects and source animals. Recruitment and xenotransplantation will occur over 5 years with study follow-up extending 1 year after xenotransplantation. Primary outcome variables surround patient safety, such as patient survival and the rate of zoonotic disease transmission. Secondary outcome variables include commonly used metrics of graft survival and function.
detailed description
Twenty patients with ESKD listed for kidney allotransplantation at UAB will be enrolled to receive either one or two porcine kidney xenotransplants from a 10-GE pig donor, contingent on the pig's overall size at the time of procurement.
Recruitment and xenotransplantation will occur over a five-year time period. Patients will undergo follow-up of one year post-xenotransplant with study extension if graft survival exceeds one year.
Participants will undergo prospective crossmatching with a 10-GE pig to determine histocompatibility prior to xenotransplant. After performance of a negative crossmatch, procurement of the donor pig will occur in a surgical suite at the designated pathogen-free facility near the UAB campus where the donor herd is maintained.
Porcine kidney(s) will be transported under sterile and hypothermic conditions to the main UAB hospital. The porcine kidney(s) will be transplanted into the research subject in standard surgical fashion within the abdomen and immunosuppression will be administered. The induction immunosuppression regimen utilized will mirror that used in human-to-human allotransplantation; this regimen represents current standard-of-care. After transplantation, kidney health will be assessed biochemically, histologically, and radiographically. Subjects will be monitored for potential zoonotic disease transmission and blood-based chimerism as well as thrombocytopenia or indicators of consumptive coagulopathy, development of anti-human leukocyte antigen antibody/alloantibody sensitization.
FOLLOW-UP PHASE
Xenotransplant recipients are expected to remain in the hospital under close clinical surveillance by the study team and associates for approximately 1-3 weeks, pending kidney recovery and surveillance for potential complications.
Post-transplant Medications. The post-transplant immunosuppression and maintenance regimen consists of conventional agents that are routinely used in kidney allotransplantation. Although immunosuppression practices in allotransplantation can vary widely from center to center, the approach below utilizes agents and doses employed by UAB's Incompatible Kidney Transplant Program. As the ideal immunosuppression regimen for xenotransplantation has not yet been established, Investigator and team have adopted strategies used in incompatible kidney allotransplantation based on the assumption that significant antigenic variation remains between the species and antibody responses of unknown specificity below the level of detection of the crossmatch may impact later function or graft longevity.