Transplant Surgery

How to interpret donor-derived cell-free DNA across platforms and organs

This review synthesizes current evidence on donor-derived cell-free DNA (dd-cfDNA) as a minimally invasive marker of allograft injury in solid organ transplantation. It compares next-generation sequencing and PCR-based assays, emphasizing differences in genotyping requirements, analytical sensitivity, confounders, and turnaround time. The authors highlight non-rejection causes of elevation—early post-operative injury, infection, leukopenia, and multi-organ DNA sources—that limit specificity for rejection. They stress that dd-cfDNA is best used to support early injury detection, risk stratification, and biopsy decisions rather than as a standalone diagnostic. 1

When prednisone avoidance is reasonable after abdominal organ transplantation

This narrative review evaluates prednisone avoidance (AoP) after abdominal solid organ transplantation using randomized trials, registries, and meta-analyses. In low-risk kidney recipients, some studies show more early acute rejection with AoP, but steroid-resistant rejection and long-term survival are generally unchanged. Across several cohorts, including some higher-risk groups, AoP provides similar graft and patient survival while improving metabolic profile, bone health, and fractures. Benefits also include reduced new-onset diabetes, lower cardiovascular risk, and improved growth in pediatric recipients. 2

Hypothermic oxygenated perfusion supports 48-hour porcine heart preservation with functional recovery

This porcine study compares hypothermic oxygenated perfusion (HOPE) with static cold storage (SCS) for prolonged ex vivo heart preservation. HOPE-preserved hearts maintained cardiomyocyte viability, structural integrity, and favorable histology for up to 48 hours versus progressive injury with SCS. Transcriptomic and metabolomic analyses showed preserved energy-substrate profiles under HOPE, while SCS hearts accumulated ischemic metabolites. During bench-top normothermic reperfusion, all HOPE hearts regained stable sinus rhythm, unlike SCS-preserved hearts. 3

NKX6.1 mRNA copy number as a potency criterion for clinical islet preparations

This study tests NKX6.1 mRNA copy number as a pretransplant potency biomarker for clinical islet lots. Across 114 preparations, digital PCR–measured NKX6.1 copies correlated linearly with islet graft function in a mouse bioassay, independent of mass, purity, and viability. In 34 patients receiving multiple preparations, total NKX6.1 copy number improved prediction of primary graft function versus islet mass alone. Higher NKX6.1 copy number independently associated with better 10-year islet graft survival and insulin independence in adjusted Cox models. 4