Leeaphorn, Napat

ABSTRACT Background Post‐transplant malignancy is a major determinant of long‐term outcomes after solid organ transplantation. Whether simultaneous pancreas–kidney (SPK) transplantation confers a differential post‐transplant cancer risk compared With kidney transplantation alone (KA) remains uncertain. Methods We conducted a retrospective propensity score–matched cohort study of adult transplant recipients at three Mayo Clinic sites between 2001 and 2017. SPK recipients ( n = 484) were matched 1:1 with KA recipients using propensity scores. The primary outcome was post‐transplant cancer incidence analyzed using Fine–Gray competing risks regression with death as a competing event. Standardized incidence ratios (SIRs) were calculated relative to the US general population. Cox proportional hazards models with cancer modeled as a time‐varying covariate evaluated associations with mortality and death‐censored graft failure. Results Over a median follow‐up of 10 years, overall cancer incidence was similar between SPK and KA recipients (subdistribution hazard ratio [sHR] 0.80, 95% CI 0.63–1.02; p = 0.07). The observed trend toward lower cancer incidence in SPK recipients was driven by a lower incidence of non‐melanoma skin cancer (NMSC) (sHR 0.72, 95% CI 0.53–0.97; p = 0.03), which was attenuated after age adjustment (sHR 0.76, p = 0.07). Incidence of other malignancies did not differ between groups. Compared with the US general population, cancer risk excluding NMSC was approximately twofold higher in both cohorts (SIR 2.18 for SPK vs. 2.23 for KA). Incident malignancy was strongly associated with increased mortality (HR 3.40 in KA and 2.07 in SPK) but not with a statistically significant increase in graft failure. Conclusions In this propensity score–matched cohort study, overall post‐transplant malignancy incidence was comparable between SPK and KA recipients. Both groups experienced substantially elevated cancer risk relative to the general population, and incident malignancy was strongly associated with mortality. These findings suggest that malignancy risk is driven primarily by shared immunologic and demographic factors rather than transplant type.

ABSTRACTBackground and AimsOne strategy to minimize the risk of posttransplant lymphoproliferative disorder (PTLD) is to avoid an Epstein–Barr Virus (EBV) mismatch through kidney paired donation. We aimed to estimate the incidence of PTLD in EBV‐negative kidney transplant recipients with EBV‐positive donors (D+/R−) and evaluate the excess risk of death following the occurrence of PTLD.MethodsWe included adult patients in OPTN database who underwent kidney transplants between 2012 and 2022. Cox regression analysis was employed to evaluate the impact of EBV serostatus on the development of PTLD, and to assess mortality following PTLD diagnosis in D+/R− individuals.ResultsA total of 179 068 patients were included, with 92.8% in the R+, 6.4% in the D+/R−, and 0.8% in the D−/R− group. D+/R− exhibited a significantly higher risk of PTLD compared to R+ and D−/R− groups. D+/R− had a greater risk of PTLD when compared to D−/R− recipients (aHR: 3.82; p < 0.001). Among D+/R− recipients, those who developed PTLD had a significantly higher risk of mortality (aHR: 2.28; p < 0.001 in deceased donor kidney transplant [DDKT] and aHR: 5.22; p < 0.001 in living donor kidney transplant [LDKT]).ConclusionsD+/R− recipients have nearly a fourfold higher risk of PTLD compared to D−/R− recipients, suggesting that choosing an EBV D−/R− transplant could reduce the PTLD risk by about 73%. This data is crucial for counseling EBV‐negative patients considering kidney paired donation to avoid an EBV serostatus mismatch.

ABSTRACTBackgroundDespite many people awaiting kidney transplant, kidney allografts from acute kidney injury (AKI) donors continue to be underutilized. We aimed to cluster kidney transplant recipients of AKI kidney allografts using an unsupervised machine learning (ML) approach.MethodsUsing Organ Procurement and Transplantation Network–United Network for Organ Sharing (OPTN/UNOS) data, a consensus clustering cohort analysis was performed in 12 356 deceased donor kidney transplant recipients between 2015 and 2019 in whom donors had a terminal serum creatinine ≥1.5 mg/dL. Significant cluster characteristics were determined, and outcomes were compared.ResultsThe median donor terminal creatinine was 2.2 (interquartile range [IQR] 1.7–3.3) mg/dL. Cluster analysis was performed on 12 356 AKI kidney recipients, and three clinically distinct clusters were identified. Young, sensitized kidney re‐transplant patients characterized Cluster 1. Cluster 2 was characterized by first‐time kidney transplant patients with hypertensive and diabetic kidney diseases. Older diabetic recipients characterized Cluster 3. Clusters 1 and 2 donors were young and met standard kidney donor profile index (KDPI) criteria; Cluster 3 donors were older, more likely to have hypertension or diabetes, and meet high KDPI criteria. Cluster 1 had a higher risk of acute rejection, 3‐year patient death, and graft failure. Cluster 3 had a higher risk of death‐censored graft failure, patient death, and graft failure at 1 and 3 years. Cluster 2 had the best patient‐, graft‐, and death‐censored graft survival at 1 and 3 years. Compared to non‐AKI kidney recipients, the AKI clusters showed a higher incidence of delayed graft function (DGF, AKI: 43.2%, 41.7%, 45.3% vs. non‐AKI: 25.5%); however, there were comparable long‐term outcomes specific to death‐censored graft survival (AKI: 93.6%, 93.4%, 90.4% vs. non‐AKI: 92.3%), patient survival (AKI: 89.1%, 93.2%, 84.2% vs. non‐AKI: 91.2%), and overall graft survival (AKI: 84.7%, 88.2%, 79.0% vs. non‐AKI: 86.0%).ConclusionsIn this unsupervised ML approach study, AKI recipient clusters demonstrated differing, but good clinical outcomes, suggesting opportunities for transplant centers to incrementally increase kidney utilization from AKI donors.