Design and testing of a humanized porcine donor for xenotransplantation

Nature · 2023 · 256 citations

• Biology
• Immunology
• Medicine

have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts.

The demise of islet allotransplantation in the United States: A call for an urgent regulatory update

American Journal of Transplantation · 2020 · 50 citations

• Political Science
• Medicine
• Intensive care medicine

Liver Transplantation Outcomes in a U.S. Multicenter Cohort of 789 Patients With Hepatocellular Carcinoma Presenting Beyond Milan Criteria

Hepatology · 2020 · 113 citations

• Medicine
• Internal medicine
• Gastroenterology

BACKGROUND AND AIMS: The Organ Procurement and Transplantation Network recently approved liver transplant (LT) prioritization for patients with hepatocellular carcinoma (HCC) beyond Milan Criteria (MC) who are down-staged (DS) with locoregional therapy (LRT). We evaluated post-LT outcomes, predictors of down-staging, and the impact of LRT in patients with beyond-MC HCC from the U.S. Multicenter HCC Transplant Consortium (20 centers, 2002-2013). APPROACH AND RESULTS: Clinicopathologic characteristics, overall survival (OS), recurrence-free survival (RFS), and HCC recurrence (HCC-R) were compared between patients within MC (n = 3,570) and beyond MC (n = 789) who were down-staged (DS, n = 465), treated with LRT and not down-staged (LRT-NoDS, n = 242), or untreated (NoLRT-NoDS, n = 82). Five-year post-LT OS and RFS was higher in MC (71.3% and 68.2%) compared with DS (64.3% and 59.5%) and was lowest in NoDS (n = 324; 60.2% and 53.8%; overall P < 0.001). DS patients had superior RFS (60% vs. 54%, P = 0.043) and lower 5-year HCC-R (18% vs. 32%, P < 0.001) compared with NoDS, with further stratification by maximum radiologic tumor diameter (5-year HCC-R of 15.5% in DS/<5 cm and 39.1% in NoDS/>5 cm, P < 0.001). Multivariate predictors of down-staging included alpha-fetoprotein response to LRT, pathologic tumor number and size, and wait time >12 months. LRT-NoDS had greater HCC-R compared with NoLRT-NoDS (34.1% vs. 26.1%, P < 0.001), even after controlling for clinicopathologic variables (hazard ratio [HR] = 2.33, P < 0.001) and inverse probability of treatment-weighted propensity matching (HR = 1.82, P < 0.001). CONCLUSIONS: In LT recipients with HCC presenting beyond MC, successful down-staging is predicted by wait time, alpha-fetoprotein response to LRT, and tumor burden and results in excellent post-LT outcomes, justifying expansion of LT criteria. In LRT-NoDS patients, higher HCC-R compared with NoLRT-NoDS cannot be explained by clinicopathologic differences, suggesting a potentially aggravating role of LRT in patients with poor tumor biology that warrants further investigation.

Phase 3 trial of human islet-after-kidney transplantation in type 1 diabetes

American Journal of Transplantation · 2020 · 107 citations

• Medicine
• Internal medicine
• Intensive care medicine