OBJECTIVE: Post-transplant diabetes mellitus (PTDM) is a complex condition arising from various factors including immunosuppressive medications, insulin resistance, impaired insulin secretion, and inflammatory processes. Its impact on patient and graft survival is a significant concern in kidney transplant recipients. PTDM\'s impact on kidney transplant recipients, including patient and graft survival and cardiovascular mortality, is a significant concern, given conflicting findings in previous studies. This meta-analysis was imperative to not only incorporate emerging evidence but also to delve into cause-specific mortality considerations. We aimed to comprehensively evaluate the association between PTDM and clinical outcomes, including all-cause and cardiovascular mortality, sepsis-related mortality, malignancy-related mortality, and graft loss, in kidney transplant recipients.
METHODS: PubMed, Ovid/Medline, Web of Science, Scopus, and Cochrane Library databases were screened and studies evaluating the effect of PTDM on all-cause mortality, cardiovascular mortality, sepsis-related mortality, malignancy-related mortality, and overall graft loss in adult kidney transplant recipients were included.
RESULTS: 53 studies, encompassing a total of 138,917 patients, to evaluate the association between PTDM and clinical outcomes were included. Our analysis revealed a significant increase in all-cause mortality (RR 1.70, 95% CI 1.53 to 1.89, P<0.001) and cardiovascular mortality (RR 1.86, 95% CI 1.36 to 2.54, P<0.001) among individuals with PTDM. Moreover, PTDM was associated with a higher risk of sepsis-related mortality (RR 1.96, 95% CI 1.51 to 2.54, P<0.001) but showed no significant association with malignancy-related mortality (RR 1.20, 95% CI 0.76 to 1.88). Additionally, PTDM was linked to an increased risk of overall graft failure (RR 1.33, 95% CI 1.16 to 1.54, P<0.001).
CONCLUSIONS: These findings underscore the importance of comprehensive management strategies and the need for research targeting PTDM to improve outcomes in kidney transplant recipients.

Graft failure and recipient death with functioning graft are important competing outcomes after kidney transplantation. Risk prediction models typically censor for the competing outcome thereby overestimating the cumulative incidence. The magnitude of this overestimation is not well-described in real-world transplant data. This retrospective cohort study analyzed data from the European Collaborative Transplant Study (CTS; n = 125 250) and from the American Scientific Registry of Transplant Recipients (SRTR; n = 190 258). Separate cause-specific hazard models, using donor and recipient age as continuous predictors, were developed for graft failure and recipient death. The hazard of graft failure increased quadratically with increasing donor age and decreased decaying with increasing recipient age. The hazard of recipient death increased linearly with increasing donor and recipient age. The cumulative incidence overestimation due to competing risk-censoring was largest in high-risk populations for both outcomes (old donors/recipients), sometimes amounting to 8.4 and 18.8 percentage points for graft failure and recipient death, respectively. In our illustrative model for post-transplant risk prediction, the absolute risk of graft failure and death is overestimated when censoring for the competing event, mainly in older donors and recipients. Prediction models for absolute risks should treat graft failure and death as competing events.

BACKGROUND: Direct peritoneal resuscitation (DPR) is associated with improved outcomes in trauma. Animal models suggest DPR has favorable effects on the liver. We sought to evaluate its safety and assess for improved outcomes in liver transplantation (LT).
METHODS: LT patients with renal dysfunction and/or obesity were enrolled in a phase-I clinical trial. DPR lasted 8-24 ​h depending on postoperative disposition. Primary outcome was percent of patients completing DPR. Secondary outcomes evaluated complications. Controls with either obesity (control-1) or both risk factors (obesity ​+ ​renal dysfunction, control-2) were analyzed.
RESULTS: Fifteen patients were enrolled (seven with both criteria and eight with obesity alone). DPR was completed in 87 ​% of patients, with one meeting stopping criteria. Controls included 45 (control-1) and 24 (control-2) patients. Return to operating room, graft loss, and late infections were lower with DPR.
CONCLUSIONS: DPR appears to be safe in closed abdomens following LT, warranting a follow-up phase-II trial to assess efficacy.

Rejection is one of the major factors affecting the long-term prognosis of kidney transplantation, and timely recognition and aggressive treatment of rejection is essential to prevent disease progression. RBPs are proteins that bind to RNA to form ribonucleoprotein complexes, thereby affecting RNA stability, processing, splicing, localization, transport, and translation, which play a key role in post-transcriptional gene regulation. However, their role in renal transplant rejection and long-term graft survival is unclear. The aim of this study was to comprehensively analyze the expression of RPBs in renal rejection and use it to construct a robust prediction strategy for long-term graft survival. The microarray expression profiles used in this study were obtained from GEO database. In this study, a total of eight hub RBPs were identified, all of which were upregulated in renal rejection samples. Based on these RBPs, the renal rejection samples could be categorized into two different clusters (cluster A and cluster B). Inflammatory activation in cluster B and functional enrichment analysis showed a strong association with rejection-related pathways. The diagnostic prediction model had a high diagnostic accuracy for T cell mediated rejection (TCMR) in renal grafts (area under the curve = 0.86). The prognostic prediction model effectively predicts the prognosis and survival of renal grafts (p < .001) and applies to both rejection and non-rejection situations. Finally, we validated the expression of hub genes, and patient prognosis in clinical samples, respectively, and the results were consistent with the above analysis.

BACKGROUND: As there is no specific antiviral treatment currently available for BK polyomavirus associated nephropathy (BKVAN), its management relies on immunosuppression reduction in kidney transplant patients. Data on efficacy of steroid pulses in this indication are lacking.
METHODS: We performed a retrospective monocenter study on 64 patients diagnosed with biopsy-proven BKVAN. Patients within the \"pulse group\" (n = 37) received IV methylprednisolone 10 mg/kg 3 days consecutively. In the \"low dose\" steroid group (n = 27), patients were continued oral prednisone 5 mg daily.
RESULTS: Mean follow up was 78 months in the steroid pulse group and 56 months in the low dose group (p = 0.15). Mean eGFR values at diagnosis were comparable, as well as other demographic characteristics. Mean BK plasma viral load was higher in \"pulse\" than in \"low dose\" steroid group. Pulse group had higher inflammation and tubulitis (p < 0.05). Graft loss reached 57% in the \"pulse\" group versus 41% in the \"low dose\" group, p = 0.20. Rejection events were similar. No major adverse event was statistically associated with steroid pulse, including infections, cancer, and de novo diabetes.
CONCLUSIONS: No significant differences were found in the evolution of both groups of patients, despite patients receiving \"pulse\" steroids were identified as the most severe sharing higher BK viral load and more frequent active lesions on histology.

UNASSIGNED: Antibody-mediated rejection (ABMR) significantly affects transplanted kidney survival, yet the macrophage phenotype, ontogeny, and mechanisms in ABMR remain unclear.
UNASSIGNED: We analyzed post-transplant sequencing and clinical data from GEO and ArrayExpress. Using dimensionality reduction and clustering on scRNA-seq data, we identified macrophage subpopulations and compared their infiltration in ABMR and non-rejection cases. Cibersort quantified these subpopulations in bulk samples. Cellchat, SCENIC, monocle2, and monocle3 helped explore intercellular interactions, predict transcription factors, and simulate differentiation of cell subsets. The Scissor method linked macrophage subgroups with transplant prognosis. Furthermore, hdWGCNA, nichnet, and lasso regression identified key genes associated with core transcription factors in selected macrophages, validated by external datasets.
UNASSIGNED: Six macrophage subgroups were identified in five post-transplant kidney biopsies. M1-like infiltrating macrophages, prevalent in ABMR, correlated with pathological injury severity. MIF acted as a primary intercellular signal in these macrophages. STAT1 regulated monocyte-to-M1-like phenotype transformation, impacting transplant prognosis via the IFNγ pathway. The prognostic models built on the upstream and downstream genes of STAT1 effectively predicted transplant survival. The TLR4-STAT1-PARP9 axis may regulate the pro-inflammatory phenotype of M1-like infiltrating macrophages, identifying PARP9 as a potential target for mitigating ABMR inflammation.
UNASSIGNED: Our study delineates the macrophage landscape in ABMR post-kidney transplantation, underscoring the detrimental impact of M1-like infiltrating macrophages on ABMR pathology and prognosis.

BACKGROUND: Impacts of ischemic time (IT) on pediatric heart transplant outcomes are multifactorial. We aimed to analyze the effect of prolonged IT on graft loss after pediatric heart transplantation. We hypothesized that graft survival with prolonged IT has improved across eras.
METHODS: Patients <18 years old in the Pediatric Heart Transplant Society database were included (N=6,765) and stratified by diagnosis and era (1993-2004, 2005-2009, and 2010-2019). Severe graft failure (SGF) was defined as death, retransplant, or need for mechanical circulatory support in the first 7 days post-transplant. Descriptive statistical methods were used to compare differences between patient characteristics and IT. Kaplan-Meier survival analysis compared freedom from graft loss, rejection, and infection. Multivariable analysis was performed for graft loss and SGF (hazard and logistic regression modeling, respectively).
RESULTS: Diagnoses were cardiomyopathy (N = 3,246) and congenital heart disease (CHD; N = 3,305). CHD were younger, more likely to have an IT ≥4.5 hours, and more likely to require extracorporeal membrane oxygenation or mechanical ventilation at transplant (all p < 0.001). Median IT was 3.6 hours (interquartile range 2.98-4.31; range 0-10.5). IT was associated with early graft loss (HR 1.012, 95% CI 1.005-1.019), but not when analyzed only in the most recent era. IT was associated with SGF (OR 1.016 95%CI 1.003-1.030).
CONCLUSIONS: Donor IT was independently associated with an increased risk of graft loss, albeit with a small effect relative to other risk factors. Graft survival with prolonged IT has improved in the most recent era but the risk of SGF persists.

The routine use of donor-derived cell-free DNA (dd-cfDNA) assays to monitor graft damage in patients after kidney transplantation is being implemented in many transplant centers worldwide. The interpretation of the results can be complicated in the setting of multiple sequential kidney transplantations where accurate donor assignment of the detected dd-cfDNA can be methodologically challenging.
We investigated the ability of a new next-generation sequencing (NGS)-based dd-cfDNA assay to accurately identify the source of the detected dd-cfDNA in artificially generated samples as well as clinical samples from 31 patients who had undergone two sequential kidney transplantations.
The assay showed a high accuracy in quantifying and correctly assigning dd-cfDNA in our artificially generated chimeric sample experiments over a clinically meaningful quantitative range. In our clinical samples, we were able to detect dd-cfDNA from the first transplanted (nonfunctioning) graft in 20% of the analyzed patients. The amount of dd-cfDNA detected from the first graft was consistently in the range of 0.1%-0.6% and showed a fluctuation over time in patients where we analyzed sequential samples.
This is the first report on the use of a dd-cfDNA assay to detect dd-cfDNA from multiple kidney transplants. Our data show that a clinically relevant fraction of the transplanted patients have detectable dd-cfDNA from the first donor graft and that the amount of detected dd-cfDNA is in a range where it could influence clinical decision-making.

Living donor (LD) kidney transplantation in the setting of ABO blood group incompatibility (ABOi) has been previously reported to be associated with increased risk for antibody-mediated rejection (ABMR). It is however unclear if the presence of pre-transplant donor specific antibodies (DSA) works as an additive risk factor in the setting of ABOi and if DSA positive ABOi transplants have a significantly worse long-term outcome as compared with ABO compatible (ABOc) DSA positive transplants.
We investigated the effect of pre-transplant DSA in the ABOi and ABOc setting on the risk of antibody-mediated rejection (ABMR) and graft loss in a cohort of 952 LD kidney transplants.
We found a higher incidence of ABMR in ABOi transplants as compared to ABOc transplants but this did not significantly affect graft survival or overall survival which was similar in both groups. The presence of pre-transplant DSA was associated with a significantly increased risk of ABMR and graft loss both in the ABOi and ABOc setting. We could not detect an additional risk of DSA in the ABOi setting and outcomes were comparable between DSA positive ABOi and ABOc recipients. Furthermore, a combination of DSA directed at both Class I and Class II, as well as DSA with a high mean fluorescence intensity (MFI) showed the strongest relation to ABMR development and graft loss.
The presence of pre-transplant DSA was associated with a significantly worse long-term outcome in both ABOi and ABOc LD kidney transplants and our results suggests that the risk associated with pre-transplant DSA is perhaps not augmented in the ABOi setting. Our study is the first to investigate the long-term effects of DSA in the ABOi setting and argues that pre-transplant DSA risk could potentially be evaluated similarly regardless of ABO compatibility status.

Infection with BK polyomavirus (BKPyV) is a common opportunistic infection after kidney transplantation (KT) and may affect graft function. We aimed to determine the incidence, risk factors, and clinical outcomes of BKPyV DNAemia in a prospective cohort of 601 KT recipients transplanted from 2012 to 2020. BKPyV PCR on plasma was performed at days 60, 90, 180, 270, and 360 post-KT. Any BKPyV DNAemia was defined as a single BKPyV DNA of ≥1000 copies/mL. Severe BKPyV DNAemia was defined as two consecutive BKPyV DNA of ≥10,000 copies/mL. Cumulative incidences were investigated using the Aalen-Johansen estimator, and the risk factors were investigated in Cox proportional hazard models. The incidence of any BKPyV DNAemia and severe BKPyV DNAemia was 21% (18-25) and 13% (10-16) at one year post-KT, respectively. Recipient age > 50 years (aHR, 1.72; 95% CI 1.00-2.94; p = 0.049), male sex (aHR, 1.96; 95% CI 1.17-3.29; p = 0.011), living donors (aHR, 1.65; 95% CI 1.03-2.74; p = 0.045), and >3 HLA-ABDR mismatches (aHR, 1.72; 95% CI 1.01-2.94; p = 0.046) increased the risk of severe BKPyV DNAemia. Any BKPyV DNAemia was associated with an increased risk of graft function decline (aHR, 2.26; 95% CI 1.00-5.12; p = 0.049), and severe BKPyV DNAemia was associated with an increased risk of graft loss (aHR, 3.18; 95% CI 1.06-9.58; p = 0.039). These findings highlight the importance of BKPyV monitoring post-KT.