Citations

Since the first successful kidney transplant in 1954, transplant medicine has advanced significantly, achieving favorable one-year outcomes. However, despite excellent short-term outcomes, long-term renal allograft survival remains sub-optimal, with acute rejection continuing to be a major contributor to death-censored allograft loss. Current approaches for post-transplant surveillance and rejection monitoring rely on either nonspecific markers that often detect injury late in their course or invasive procedures associated with procedural risks and complications. To address these limitations, numerous non-invasive biomarkers have been introduced into solid organ transplantation research with the goal of improving allograft surveillance, facilitating earlier detection of rejection and complementing existing diagnostic approaches. Although several biomarkers have demonstrated clinical promise, none currently possess sufficient accuracy to replace kidney allograft biopsy. Biomarkers under investigation include blood-, tissue- and urine-based specimens. Their development and validation as independent markers have been limited by smaller sample size, heterogenous targets, variable performance characteristics and suboptimal sensitivity and specificity. In response, the field has increasingly shifted toward multimodal approaches that combine biomarkers and incorporate artificial intelligence to improve diagnostic accuracy and outcomes prediction. This review summarizes current biomarkers, discusses their limitations and explores future directions for biomarker development and clinical implementation.

ABSTRACT Aim The supply of donor kidneys (living and deceased) has fallen far behind the need, while the number of patients with end stage kidney disease continues to rise, increasing their risk of cardiovascular mortality. Kidney transplant candidates frequently exhibit large artery calcification, a major contributor to cardiovascular death. This study aimed to evaluate the relationship between abdominal arterial calcification (AAC) and survival in patients awaiting kidney transplant. Methods We modified the coronary calcium scoring method (Modified Agatston Method) and applied it to quantify AAC. This retrospective study included all adult patients ( N = 4184) listed for kidney transplant from 2005 to 2023 who had undergone abdominal computed tomography (CT) scans. Patients were categorised into two groups: those who died while on the waiting list (DWL) and those who survived (SWL). Results Among 4184 candidates, 446 (10.7%) died while on the waiting list, and 3738 (89.3%) survived to transplant or study end. Patients in the DWL group had significantly higher AAC scores across all vascular sites. The median total AAC score was 3605.8 (IQR 780.1–9017.3) in the DWL group versus 940.1 (IQR 49.2–4915.0) in the SWL group. Each 1000‐point increase in total AAC was associated with a 5.1% increase in mortality risk (HR 1.051; p < 0.001). An AAC cutoff of > 1769 correlated with reduced 5‐year survival (45.4% vs. 77.4%, p < 0.001). Conclusion AAC scoring on non‐contrast abdominal CT represents a noninvasive biomarker of mortality in kidney transplant waitlist patients and may enhance risk stratification and personalised care.

ABSTRACT Background Abdominal arterial calcification (AAC) is a common comorbidity in patients with end‐stage kidney disease (ESKD) and a predictor of cardiovascular events post‐kidney transplant. However, prior studies lacked a standardized approach to evaluate AAC and its impact on post‐transplant outcomes. This study aimed to correlate AAC score values with post‐kidney transplant outcomes using a modified scoring system traditionally applied to coronary artery calcification. Methods This retrospective study included 14 339 adult patients listed for kidney transplant between 2002 and 2023 at three transplant centers. Among them, 3683 patients met the criteria of undergoing a kidney transplant and an abdominal computed tomography (CT) scan pre‐transplant. We modified the coronary calcium score software by adjusting intake data points to quantify calcification in the abdominal aorta, common iliac, external iliac, and internal iliac arteries. Outcomes focused on post‐transplant mortality. Results In 3683 kidney transplant recipients, higher AAC scores were significantly associated with increased mortality. Each 1000‐unit increase in AAC score elevated hazard ratios (HRs) across arterial regions, including 1.116 for the aorta and 1.389 for the internal iliac (all p < 0.001). Adjusted analyses confirmed AAC as an independent risk factor for mortality. Kaplan–Meier curves demonstrated lower survival with increasing AAC quartiles. Conclusions AAC, measured by a standardized score, is a significant mortality risk factor in kidney transplant recipients. Integrating AAC scores into pre‐transplant evaluations could enhance risk stratification and improve outcomes. Prospective studies are needed to validate these findings and explore interventions to reduce AAC and improve survival.

ABSTRACTIntroductionThe diagnosis of antibody‐mediated rejection (AMR) requires input from several transplant professionals. Bringing clinical and laboratory experts together may help standardize care. Yet, little is known about current global practices of multidisciplinary meetings for AMR management.MethodsThe Banff Antibody‐Mediated Injury Working Group approached professional societies worldwide to distribute a survey on the availability, content, participants, perceived value, and barriers to the implementation of multidisciplinary meetings.ResultsFour hundred two transplant professionals from six continents caring for kidney (90.55%), liver (21.14%), pancreas (20.65%), heart (15.17%), and lung (14.18%) transplant recipients participated in the survey, and 302 (75.12%) reported attending multidisciplinary meetings. Multidisciplinary meetings were more prevalent in academic centers, in high‐ versus low‐to‐middle‐income regions (81.03% and 65.99%, respectively; p < 0.001), and in mid‐to‐large size transplant programs compared to smaller programs. Perceived value included continued professional development (97.68%) and trainee education (95.70%). AMR was reported to be discussed at these meetings by 217 respondents with case presentations reviewing patient characteristics, histology, and HLA antibody data. A third of the respondents reviewed non‐HLA/pathogenic autoantibodies and/or molecular diagnostics, with the latter being more frequently applied in high‐ versus low‐to‐middle‐income regions (46.71% and 12.31%, respectively; p < 0.001). AMR case presentations allowed diagnosis revision, actionable management plans and were perceived as improving care. The primary barrier to the implementation of multidisciplinary meetings (63.27%) was the unavailability of transplant professionals (e.g., transplant immunologists).ConclusionFacilitating multidisciplinary meetings through the remote participation of pertinent experts and incentivizing participation through remuneration, protected time, or continued medical education may help standardize AMR diagnosis and harmonize its management.

Key Points Nonimmunologic AKI-related rehospitalizations post–kidney transplant are associated with poorer long-term allograft and recipient outcomes. These data are not reported to United Network for Organ Sharing, and there are no datasets highlighting this important association; thus, our findings are valuable to clinicians. We hope to help the community create a cohort of higher risk transplant patients who need closer monitoring to potentially increase graft longevity Background AKI is associated with an increased risk of CKD and ESKD. However, only limited studies have investigated the effect of AKI episodes on kidney transplant outcomes. This study evaluated the effect of rehospitalization associated with nonimmunologic AKI on long-term outcomes. Data on rehospitalization with AKI after kidney transplant are not reported to United Network for Organ Sharing, and thus, there are no large datasets available to study this association. Methods We completed chart reviews of 989 deceased donor kidney transplant recipients transplanted from 2010 to 2014 at 13 transplant centers in the Deceased Donor Study Consortium. Rehospitalizations up to 5 years post-transplant were included. The cause of rehospitalizations was adjudicated by a transplant nephrologist on the basis of the discharge diagnosis. Primary outcomes were the effect of AKI-related rehospitalization on death-censored graft failure and all-cause mortality. We excluded rehospitalizations because of acute rejection from the primary analysis. The cohort was linked to data from Organ Procurement and Transplantation Network supplied by United Network for Organ Sharing. Time-varying cox-proportional hazard models were used to examine the association between rehospitalization and outcomes. Results We identified 200 (20%) recipients with at least one rehospitalization associated with AKI, 516 (52%) with rehospitalizations without AKI, and 273 (28%) without a rehospitalization post-transplant. Delayed graft function, donor age, and kidney donor profile index score differed between the three groups. We found a higher risk of death censored graft failure adjusted hazard ratio (aHR) 7.5 (95% confidence interval [CI], 4.0 to 13.8), all-cause graft failure aHR 6.7 (95% CI, 4.2 to 10.8), and all-cause mortality aHR 5.7 (95% CI, 2.7 to 11.8) for rehospitalizations associated with AKI compared with no rehospitalization. The non-AKI rehospitalizations also had significantly higher rates of measured outcomes; however, the associations were not as strong. Conclusions AKI rehospitalizations were associated with a significantly increased risk of poorer graft outcomes, and thus, closer follow-up of this high-risk group is warranted.

Background: Cardiovascular disease remains the most common cause of death among kidney transplant recipients, with hypertension being one of the most prevalent risk factors. Understanding the current prevalence of hypertension in this population is critical to help shape post-transplant care policies and guidelines and ensure proper management of CVD risk. Methods: We included all kidney transplant recipients who received their transplant between 2019 and 2023 at our center and who completed 24-hour ABPM at 12 months post-transplant. We reported data in mean (SD) unless noted otherwise. BP was categorized per AHA guidelines. This study was deemed exempt by the IRB. Results: A total of 940 patients were included in this study. Detailed results are seen in Figure 1 and Table 1. Notable to mention that 60% of the patients had blood pressure > 130/80 mmHg at 12 months post kidney transplant, with the majority being stage 1. Patients with more severe hypertension tended to be older, had lower eGFR, and had more comorbidities. They also had lower diastolic blood pressure than stage 1 HTN patients, consistent with older age. Night-time BP was significantly higher among stage 2 HTN patients. Conclusion: Hypertension remains a prevalent condition post-kidney transplant despite the majority of patients having satisfactory kidney allograft function. Ongoing BP monitoring and assessment of out-of-office BP post-kidney transplantation is critical to ensure control of this important cardiovascular risk factor. 24-hour ABPM has several advantages in this group, including accurate measurement of out-of-office BP and detection of nocturnal hypertension, an independent risk factor for cardiovascular events. Additional studies are needed to describe the hypertension subphenotypes (e.g., sustained vs. masked) and to identify predictors of severe uncontrolled hypertension in this patient population.