Transplant Surgery

Rising cold ischemia time under new allocation policies worsens kidney graft survival

UNOS data from 2007–2023 show median kidney cold ischemia time increasing from 16 to 19.6 hours across allocation eras. Kidneys with 32–36 hours cold ischemia had about 10% higher overall graft loss versus 16–20 hours (P = 0.0002). For KDPI 20%–34% and 35%–85%, each additional ischemia hour increased graft failure risk by 0.5% and 0.4%, respectively. In the KAS250 era, out-of-sequence or expedited kidneys had four hours longer cold ischemia and were increasingly low-KDPI rather than high-KDPI. These findings argue for explicitly incorporating cold ischemia into allocation algorithms and center acceptance practices. 1

Donor-derived regulatory dendritic cells facilitate immunosuppression withdrawal in liver transplant

In this phase I/IIa trial, 15 living-donor liver candidates received donor-derived regulatory dendritic cells seven days pre-transplant. Thirteen patients were analyzable; eight met protocol criteria for starting immunosuppression withdrawal one year post-transplant. Four achieved complete withdrawal, and three remained drug-free for more than one year, averaging about three drug-free years. Among withdrawal-eligible recipients, operational tolerance reached 37.5%, higher than historical adult liver experience. Infusions were safe and well tolerated, supporting larger controlled studies of this pre-emptive tolerance strategy. 2

mBox model predicts short- and long-term mortality after kidney transplantation

This international cohort included 12,517 adult kidney recipients from 14 centers between 2004 and 2023. Fourteen clinical, biologic, imaging, and immunologic factors independently associated with mortality and were combined into the mBox prediction model. In the derivation cohort, discrimination was strong, with C-statistics 0.82 at one year and 0.80 at ten years post-transplant. Abbreviated versions maintained performance in external cohorts, with C-statistics around 0.70–0.79 across France, Europe, and North America. The computable mBox score can support perioperative counseling and tailoring of surveillance and immunosuppression intensity. 3

MASLD and advanced fibrosis are frequent and prognostically adverse after kidney transplant

Among 650 first kidney recipients, MASLD prevalence was 21.7 per 100 at transplant and 42.3 per 100 at five years. Advanced hepatic fibrosis by FIB-4 > 2.67 was present in 42.9 per 100 at transplant and 69.7 per 100 at five years. Advanced fibrosis associated with higher risk of the composite outcome versus low FIB-4 (adjusted HR 1.76; 95% CI 1.14–2.71). Death-censored graft failure risk more than tripled with advanced fibrosis compared with low FIB-4 (HR 3.28; 95% CI 1.78–6.06). These data support routine MASLD and fibrosis screening with aggressive cardiometabolic risk reduction in kidney recipients. 4