Xenotransplantation in Humans: pig organs edge closer to being clinically kosher

  It has long been the conventional wisdom in transplantation that xenotransplants--transplanting a kidney from a genetically modified pig into a human--will be tomorrow's cure for kidney failure, and always will be.

But lately there are some causes for optimism that the timeline may be quicker than that.

Here's a recent review of the evidence:

Xenotransplantation in Humans: A Reality Check, by A. Joseph Tector, MD, PhD
Transplantation 109(2):p 231-234, February 2025. | DOI: 10.1097/TP.0000000000005223 

"Thirty years after the initial strategies to develop genetically engineered pigs for use as organ donors in xenotransplantation were described, evaluation of these pig organs in humans has begun.1 The initial experience includes decedent experiments in kidneys and hearts, as well as 5 clinical cases (2 hearts, 2 kidneys, and 1 auxiliary liver). The cardiac xenograft survival was 47 and 40 d, whereas patient survival was 60 and 40 d.2-4 In the initial kidney xenografts, patient survival was 52 d for the first kidney, and the second kidney was removed at 47 d with the patient still alive in the intensive care unit. The initial results in the decedent work as well as the clinical cases indicate that the initial barrier of hyperacute rejection (HAR) has been averted with genetic engineering, but that much work remains before we can begin to offer xenotransplantation as a routine therapy for the treatment of end-stage organ failure. Evaluation of the renal xenografts in decedents and the 2 cardiac xenografts make it clear that although HAR is no longer an issue the problem of antibody-mediated rejection (AMR) secondary to xenoantigens on the pig cell remains.5,6 Moving forward, 4 key areas that must be addressed to realize the goals of bringing xenotransplantation to clinical practice are (1) patient selection, (2) donor pig genetics, (3) immunosuppression issues, and (4) animal husbandry challenges."

 

 Here's the paper's final sentence:

"The human experience suggests that clinical xenotransplantation will work sooner rather than later, but there is still some heavy lifting in front of us that will require continued careful detailed laboratory investigation guided by the feedback from preclinical evaluation."