Attieh, Rose Mary

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.

The Omicron variant of SARS-CoV-2 is associated with milder symptoms and lower hospitalization and mortality rates than Delta variants, although the impact of Omicron on immunocompromised patients, especially solid organ transplant (SOT) recipients, is still unclear. This study compares the hospitalization rate and outcomes between immunocompromised, immunocompetent, and SOT patients during the Delta and Omicron periods. We included adult patients who tested positive for SARS-CoV-2 on PCR or nasopharyngeal antigen test between 26 June 2021 to 8 September 2022, at our institution. A total of 12,401 COVID-19 patients were included, of which 11,055 were immunocompetent, and 1346 were immunocompromised (375 SOT recipients). Throughout the Delta and Omicron outbreaks, immunocompromised patients exhibited higher comorbidities and 30-day hospitalizations, but rates of mechanical ventilation and ICU-level care were like immunocompetent patients. During the Omicron wave, immunocompromised patients had higher unadjusted relative risk estimates (RR = 2.37, 95% CI 1.96–2.87, p < 0.05) than Delta (RR = 1.58, 95% CI 1.24–2.01, p < 0.05), with higher adjusted relative risk for hospitalization in Omicron (RR = 1.50, 95% CI 1.10–2.03, p = 0.01). Analyses show increased hospitalization risk in immunocompromised during the Omicron wave compared to the Delta wave, with no significant difference in hospitalization outcomes. The relative risk of hospitalization for SOT patients was higher in both waves.

Post-transplant thrombotic microangiopathy (PT-TMA) is a serious and underrecognized complication of kidney transplantation, associated with substantially reduced allograft survival. Its heterogeneous presentations, ranging from systemic to renal-limited forms, and multifactorial etiologies complicate timely diagnosis and management. Complement activation is central across all etiologies, either as a primary driver of disease in recurrent complement-mediated TMA (also known as atypical hemolytic uremic syndrome or aHUS) or as an amplifier in de novo PT-TMA (dnTMA). Accurate diagnosis requires a combination of clinical assessment, laboratory evaluation, and histopathologic examination, with particular attention to complement abnormalities, donor/recipient risk factors, and potential triggers. Management must be individualized, encompassing supportive care, optimization of immunosuppression, complement blockade, and plasmapheresis in select cases. Histologic features and clinical risk factors can guide prognosis, and scoring systems provide valuable tools for risk stratification. Despite advances in therapy, long-term outcomes remain suboptimal, particularly in antibody-mediated rejection (AMR)-related cases. Ongoing research is essential to clarify the optimal context for the use of anti-complement therapy, and to develop effective prophylactic and therapeutic strategies while maintaining adequate immunosuppression.

ABSTRACT Post-transplant lymphoproliferative disease (PTLD) remains a challenging and high-impact complication of kidney transplantation, requiring thoughtful prevention, timely recognition, and multidisciplinary management. Key strategies include careful selection of immunosuppressive regimens, particularly avoiding belatacept in Epstein–Barr virus (EBV)-seronegative recipients and exercising caution with lymphodepleting induction in EBV-mismatched pairs, along with targeted EBV surveillance in high-risk patients. Once PTLD is suspected or confirmed, accurate staging and a stepwise treatment approach beginning with reduction of immunosuppression and escalating to rituximab, chemotherapy, or advanced cellular therapies are essential, with EBV-CTLs and chimeric antigen receptor T-cell therapy offering promising options in refractory disease. Close monitoring for infectious complications, cytopenias, and rejection is critical throughout treatment. Importantly, a prior history of PTLD should not preclude future transplantation in appropriately selected patients with sustained remission. Continued research is needed to refine surveillance strategies, clarify optimal treatment sequencing, and improve long-term outcomes for kidney transplant recipients at risk for or affected by PTLD.

Purpose of review Machine learning algorithms are occupying a larger space in medical and urology applications. However, typical medical physicians are not trained on these technologies and do not master the possibilities offered by these tools, to imagine their applications in the medical field. This manuscript is indented to be a guide in the use of machine learning in different urology applications, and to demystify the available machine learning and artificial intelligence algorithms. This manuscript reviews some of their applications and potential applications to the medical and urology field. Recent findings Multiple works are published on the use of machine learning in urology, with performance demonstrated to be noninferior to human experts on multiple occasions. However, the major part of the machine learning publications in urology applications are concentrated on diagnosis and/or prognosis. Advanced machine learning algorithms based on agentic artificial intelligence, able to perform decisions and causality-based treatment optimization, are rarely put to use in urology. The democratization of advanced machine learning technologies in the medical fields can accelerate the adoption of these techniques, and potentially improve the patient care through relevant suggestive decision making. Summary This work aims to demystify the machine learning tools for medical applications, facilitate decision making and adoption of the correct tools for the correct applications, and places a roadmap for the future of machine learning in the enhancement of patient care in urology.

ABSTRACT Complement protein 3 (C3) glomerulopathy (C3G) is a rare and progressive kidney disease primarily affecting young individuals and frequently advancing to end-stage kidney disease (ESKD). For ESKD, kidney transplantation remains the optimal treatment option; however, C3G has a high recurrence rate post-transplantation, affecting over two-thirds of transplanted patients. Despite advances in our understanding of C3G, significant gaps persist regarding the optimal timing for transplantation and the best strategies for peri-transplant management. Currently, no clear evidence links functional complement levels to the risk of post-transplant recurrence. Genetic counseling is also complex, due to variable gene penetrance and weak genotype–phenotype correlations, which limit predictive accuracy. Transplant-related factors are believed to significantly influence C3G recurrence, yet there are no established methods for preventing recurrence after transplantation. Eculizumab has shown inconsistent efficacy in managing recurrent C3G. However, new proximal complement inhibitors, such as factor B and C3 inhibitors, are under investigation in clinical trials and show promise. Some of these trials include kidney transplant patients with C3G, and their outcomes could potentially shape future treatment protocols.

Objective: To address whether kidney transplant (KTx) candidates, ages 60+, should accept a high Kidney Donor Profile Index (KDPI) kidney and differences when considering a high (>85%) versus low (<85%) KDPI KTx. Background: To date, there is limited survival data to guide decision-making for patients aged ≥60 years who are faced with the choice of accepting a high KDPI kidney or remaining on the waitlist. Methods: Propensity-matched cohort study using data from United Network on Organ Sharing (2014–2021). Cox proportional hazard models and competing risk models allowed comparison of (1) patient survival on the waitlist or after KTx and (2) patient and graft survival after KTx for the second comparison between matched groups, stratified by age groups: 60 to 65, 66 to 70, and 71+. Results: Receiving a >85% KDPI kidney versus remaining on the waitlist was associated with reduced mortality [Hazard Ratio (HR): 0.68, 95% CI: 0.59–0.80, P < 0.001] overall and across the 2 oldest age groups: 66 to 70 (HR: 0.57, 95% CI: 0.44–0.73, P < 0.001) and 71+ (HR: 0.59, 95% CI: 0.44–0.83, P < 0.001). Those aged 60 to 65 did not experience a survival benefit (HR: 0.86, 95% CI: 0.67–1.11, P = 0.259). Patients ages 60+ receiving a >85% or ≤85% KDPI kidney experience comparable survival rates. Conclusions: Our study revealed a survival advantage linked to receiving a lower-quality KTx than remaining on the waitlist in the overall sample and for those 66+. Graft failure and survival were independent of the organ quality.

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.

Kidney transplantation remains the gold standard for managing end-stage kidney disease, providing superior survival and quality-of-life outcomes compared to dialysis. Despite the ongoing gap between organ availability and demand, it is inevitable that kidney transplantation will continue to grow. This is owed to broader organ sharing, increased comfort of transplant programs with marginal kidney utilization, and the expansion of paired exchange among living donor kidneys. The evolution of kidney transplantation could not have been possible without the availability of effective immunosuppressive regimens that prevent rejection and maintain graft function. Mycophenolic acid and calcineurin inhibitors continue to serve as the foundation of modern maintenance immunosuppression. While these agents have markedly reduced acute rejection rates, their long-term efficacy in graft survival remains suboptimal. Alternative immunosuppressive therapies, including belatacept and mammalian target of rapamycin inhibitors, have demonstrated potential benefits. However, concerns regarding an increased risk of rejection have limited their widespread adoption as primary treatment options. In addition to ongoing efforts to refine steroid- and calcineurin inhibitor-sparing strategies, the identification of practical and quantifiable biomarkers for predicting long-term graft survival remains a critical objective. This review evaluates contemporary immunosuppressive protocols, highlights existing challenges, and explores future directions for optimizing long-term transplant outcomes.