Safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy for living donor kidney transplantation: A comparison with left retroperitoneal laparoscopic donor nephrectomy.

INTRODUCTION: The left kidney is often preferred for living donor kidney transplantation because of its anatomical advantages. However, the right kidney may be procured due to donor conditions. Few studies have assessed the safety and graft outcome of right retroperitoneal laparoscopic donor nephrectomy (RDN). This study aimed to compare the outcomes between right and left RDN with respect to donor outcome and the graft function of recipients. METHODS: This retrospective study included 230 consecutive living donor kidney transplants performed at our institution between May 2019 and March 2023. We reviewed the outcomes of kidney transplant in the right and left kidneys after RDN. RESULTS: A total of 230 living donor kidney transplants were performed, with 32 donors receiving right RDN (right RDN group) and 198 donors receiving left RDN (left RDN group). The renal veins and ureters were significantly shorter in the right RDN group than in the left RDN group (both p < .001). Donor operation and warm ischemia time were significantly longer in the right RDN group than in the left RDN group (p = .012 and p < .001, respectively). None of the groups exhibited any cases of delayed graft function owing to donor-related reasons. Perioperative changes in the estimated glomerular filtration rate of recipients and death-censored graft survival were not significantly different between the two groups. CONCLUSIONS: In RDN, the outcomes of right donor nephrectomy were comparable to those of left donor nephrectomy in terms of donor safety and recipient renal function.

Molecular Identification of Encephalitazoon intestinalis and the Prevalence of Renal Microsporidiosis in Renal Transplant Recipients in Türkiye.

Objective: In patients with end-stage kidney disease, kidney transplantation is the kidney replacement therapy option that provides the most successful survival. However, immunosuppression agents administered after kidney transplantation can increase the risk of opportunistic infections. Microsporidia are obligate intracellular pathogens that can be fatal in immunosuppressed patients. The present study aimed to determine the prevalence of microsporidia in kidney transplantation recipients and the molecular characterization of the detected species. Methods: To evaluate the prevalence of renal microsporidiosis in kidney transplant recipients, the urine samples from a total of 325 patients were analyzed by real-time and nested polymerase chain reaction for Encephalitozoon spp. and Enterocytozoon bieneusi. Results: Only one (0.4%) sample from the adult patient was positive for the Encephalitozoon species, while no positivity was found in pediatric patients. It was determined as Encephalitozoon intestinalis by ITS rRNA gene region sequence analysis. A microsporidia species obtained from humans in Türkiye has been characterized for the first time and registered in GenBank. Conclusion: Our epidemiological results show that the prevalence of renal microsporidiosis in kidney transplant recipients is very low. In addition, as a result of the phylogenetic analysis of the detected isolate, it was observed that it was 100% identical to the isolates reported from dogs in Kayseri, Türkiye. This situation provided essential data regarding the zoonotic transmission dynamics of microsporidia.

Prediction of delayed graft function by early salivary microbiota following kidney transplantation.

Delayed graft function (DGF) is a frequently observed complication following kidney transplantation (KT). Our prior research revealed dynamic shifts in salivary microbiota post-KT with immediate graft function (IGF), yet its behavior during DGF remains unexplored. Five recipients with DGF and 35 recipients with IGF were enrolled. Saliva samples were collected during the perioperative period, and 16S rRNA gene sequencing was performed. The salivary microbiota of IGFs changed significantly and gradually stabilized with the recovery of renal function. The salivary microbiota composition of DGFs was significantly different from that of IGFs, although the trend of variation appeared to be similar to that of IGFs. Salivary microbiota that differed significantly between patients with DGF and IGF at 1 day after transplantation were able to accurately distinguish the two groups in the randomForest algorithm (accuracy = 0.8333, sensitivity = 0.7778, specificity = 1, and area under curve = 0.85), with Selenomonas playing an important role. Bacteroidales (Spearman's r = - 0.4872 and p = 0.0293) and Veillonella (Spearmen's r = - 0.5474 and p = 0.0125) were significantly associated with the serum creatinine in DGF patients. Moreover, the significant differences in overall salivary microbiota structure between DGF and IGF patients disappeared upon long-term follow-up. This is the first study to investigate the dynamic changes in salivary microbiota in DGFs. Our findings suggested that salivary microbiota was able to predict DGF in the early stages after kidney transplantation, which might help the perioperative clinical management and early-stage intervention of kidney transplant recipients. KEY POINTS: • Salivary microbiota on the first day after KT could predict DGF. • Alterations in salivary taxa after KT are related to recovery of renal function.

CCR7 and CD48 as Predicted Targets in Acute Rejection Related to M1 Macrophage after Pediatric Kidney Transplantation.

Background: Kidney transplantation (KT) is the best treatment for end-stage renal disease. Although long and short-term survival rates for the graft have improved significantly with the development of immunosuppressants, acute rejection (AR) remains a major risk factor attacking the graft and patients. The innate immune response plays an important role in rejection. Therefore, our objective is to determine the biomarkers of congenital immunity associated with AR after KT and provide support for future research. Materials and Methods: A differential expression genes (DEGs) analysis was performed based on the dataset GSE174020 from the NCBI gene Expression Synthesis Database (GEO) and then combined with the GSE5099 M1 macrophage-related gene identified in the Molecular Signatures Database. We then identified genes in DEGs associated with M1 macrophages defined as DEM1Gs and performed gene ontology (GO) and Kyoto Encyclopedia of Genomes (KEGG) enrichment analysis. Cibersort was used to analyze the immune cell infiltration during AR. At the same time, we used the protein-protein interaction (PPI) network and Cytoscape software to determine the key genes. Dataset, GSE14328 derived from pediatric patients, GSE138043 and GSE9493 derived from adult patients, were used to verify Hub genes. Additional verification was the rat KT model, which was used to perform HE staining, immunohistochemical staining, and Western Blot. Hub genes were searched in the HPA database to confirm their expression. Finally, we construct the interaction network of transcription factor (TF)-Hub genes and miRNA-Hub genes. Results: Compared to the normal group, 366 genes were upregulated, and 423 genes were downregulated in the AR group. Then, 106 genes related to M1 macrophages were found among these genes. GO and KEGG enrichment analysis showed that these genes are mainly involved in cytokine binding, antigen binding, NK cell-mediated cytotoxicity, activation of immune receptors and immune response, and activation of the inflammatory NF-κB signaling pathway. Two Hub genes, namely CCR7 and CD48, were identified by PPI and Cytoscape analysis. They have been verified in external validation sets, originated from both pediatric patients and adult patients, and animal experiments. In the HPA database, CCR7 and CD48 are mainly expressed in T cells, B cells, macrophages, and tissues where these immune cells are distributed. In addition to immunoinfiltration, CD4+T, CD8+T, NK cells, NKT cells, and monocytes increased significantly in the AR group, which was highly consistent with the results of Hub gene screening. Finally, we predicted that 19 TFs and 32 miRNAs might interact with the Hub gene. Conclusions: Through a comprehensive bioinformatic analysis, our findings may provide predictive and therapeutic targets for AR after KT.

Timing Considerations for Sleeve Gastrectomy in Kidney Transplant Patients: A Single Center Evaluation.

Current scientific literature is deficient in detailing the optimal timing for conducting bariatric surgery in relation to kidney transplantation. In this study, we performed a retrospective evaluation of kidney transplant recipients with BMI >35 kg/m2. It aimed to provide data on those who received both sleeve gastrectomy (SG) and kidney transplantation (KT) simultaneously, as well as on patients who underwent SG and KT at different times, either before or after. In addition, the acceptance levels of the bariatric surgery among different scenarios were assessed. Our findings demonstrated that combined KT and SG led to successful weight loss, in contrast to undergoing kidney transplant alone, while maintaining comparable rates of graft and patient survival. Weight loss was similar between recipients who had a combined operation and those who underwent SG following the transplant. Additionally, over a median time frame of 1.7 years, patients who underwent SG before KT exhibited a statistically significant reduction in BMI at the time of the transplant. Notably, our study highlights that patients offered the combined procedure were significantly more likely to undergo SG compared to those for whom SG was presented at a different operative time than the transplant.

Intensive Surveillance of Porcine-Rhesus Kidney Xenotransplant Using Different Ultrasound Techniques.

BACKGROUND: Significant progress has been made in kidney xenotransplantation in the past few years, and this field is accelerating towards clinical translation. Therefore, surveillance of the xenograft with appropriate tools is of great importance. Ultrasonography has been widely used in kidney allotransplantation and served as an economical and non-invasive method to monitor the allograft. However, questions remain whether the ultrasonographic criteria established for human kidney allograft could also be applied in xenotransplantation. METHODS: In the current study, we established a porcine-rhesus life sustaining kidney xenotransplantation model. The xenograft underwent intensive surveillance using gray-scale, colorful Doppler ultrasound as well as 2D shear wave elastography. The kidney growth, blood perfusion, and cortical stiffness were measured twice a day. These parameters were compared with the clinical data including urine output, chemistry, and pathological findings. RESULTS: The observation continued for 16 days after transplantation. Decline of urine output and elevated serum creatinine were observed on POD9 and biopsy proven antibody-mediated rejection was seen on the same day. The xenograft underwent substantial growth, with the long axis length increased by 32% and the volume increased by threefold at the end of observation. The resistive index of the xenograft arteries elevated in response to rejection, together with impaired cortical perfusion, while the peak systolic velocity (PSV) was not compromised. The cortical stiffness also increased along with rejection. CONCLUSION: In summary, the ultrasound findings of kidney xenograft shared similarities with those in allograft but possessed some unique features. A modified criteria needs to be established for further application of ultrasound in kidney xenotransplantation.

Assessing asymmetrical kidney function in living donors: a retrospective cohort study on CT metrics.

BACKGROUND: Live donor kidney transplantation is the preferred kidney replacement therapy for eligible patients but requires thorough donor evaluation to minimise risks. Contemporary guidelines recommend split kidney function measurement in living donors only when there is a significant kidney size discrepancy, yet the evidence for this is poor, and practice varies nationally. This study evaluates the efficacy of CT-derived kidney metrics in detecting significant functional asymmetry. METHODS: We conducted a retrospective cohort analysis of 123 prospective living kidney donors at a regional transplant centre from June 2011 to October 2014, utilising CT to determine kidney and cortical volumes and lengths. Asymmetric kidney function (AKF), defined by > 10% function difference on DMSA scans, was correlated with CT measurements to calculate the diagnostic accuracy of current guidelines. RESULTS: Among the prospective donors, the median age was 42 years, and 59.3% were female. The median split kidney function difference was 4%, with 25 individuals exhibiting > 10% AKF. Kidney length discrepancy proved to be a poor indicator of AKF (sensitivity: 28%, specificity: 84%). While negative predictive values for cortical and kidney volumes were high (96% and 93%, respectively), sensitivity was low, and specificity and positive predictive value did not meet satisfactory thresholds. CONCLUSIONS: CT-derived metrics of kidney length, cortical, and total volume show limited sensitivity and specificity in identifying significant AKF. These findings provide evidence to support revised guideline development in the assessment of living kidney donors.

The impact of preservation solutions for static cold storage on kidney transplantation outcomes: Results of a Brazilian nationwide multicenter study.

This study evaluated the current practices of selecting cold storage preservation solutions in Brazil and their impact on delayed graft function (DGF) incidence and 1-year outcomes in kidney transplant recipients. A retrospective cohort study was conducted, including 3,134 brain-dead deceased donor kidney transplants performed between 2014 and 2015 in 18 Brazilian centers. The most commonly used preservation solution was Euro-collins (EC, 55.4%), followed by Histidine-tryptophan-ketoglutarate (HTK, 30%) and Institut Georges Lopez (IGL-1, 14.6%). The incidence of DGF was 54.4%, with 11.7% of patients requiring dialysis for more than 14 days, indicating prolonged DGF. Upon adjusting for confounding variables, HTK demonstrated a significantly lower risk of DGF than EC (OR 0.7350.82500.926), as did IGL-1 (OR 0.6050.7120.837). Similar protective effects were observed for prolonged DGF when comparing HTK (OR 0.4780.5990.749) and IGL-1 (OR 0.4780.6810.749) against EC. No significant association was found between preservation solutions and 1-year death-censored graft survival. In conclusion, EC was the most frequently used cold storage perfusion solution, demonstrating a higher incidence and duration of DGF compared with HTK and IGL-1, but with no impact on 1-year graft survival.

Inter- and intra-individual differences regarding SARS-CoV-2 and influenza vaccination in pediatric kidney transplant recipients: An observational study.

In kidney transplant recipients (KTRs), viral infection can lead to antibody and/or T-cell mediated rejection, resulting in kidney transplant dysfunction. Therefore, it is critical to prevent infections. However, KTRs exhibit suboptimal responses to SARS-CoV-2 and/or influenza vaccines, partly due to immunosuppressant therapy. Inter- and intra-individual differences in the biological responses to vaccines may also affect patients' antibody production ability. This study included KTRs who received an messenger RNA SARS-CoV-2 vaccine (3 doses), and an inactivated quadrivalent influenza vaccine (1 or 2 doses). We measured the patients' total antibody titers against SARS-CoV-2 spike antigen, and hemagglutination inhibition (HI) titers against influenza A/H1N1, A/H3N2, B/Yamagata, and B/Victoria. Five patients were eligible for this study. Of these 5 KTRs, two produced anti-SARS-CoV-2 spike antibody titers to a seroprotective level, and also produced HI titers against A/H1N1 to a seroprotective level. Another 2 KTRs did not produce seroprotective anti-SARS-CoV-2 antibody titers, but produced seroprotective HI titers against A/H1N1. The remaining KTR produced a seroprotective anti-SARS-CoV-2 antibody titer, but did not produce a seroprotective HI titer against A/H1N1. The 2 KTRs who did not produce seroprotective anti-SARS-CoV-2 antibody titers following vaccination, later developed COVID-19, and this infection increased their titers over the seroprotective level. This study demonstrated that inter- and intra-individual differences in biological responses to vaccines should be considered in pediatric KTRs, in addition to immunosuppressant effects. Personalized regimens, such as augmented or booster doses of vaccines, could potentially improve the vaccination efficacy against SARS-CoV-2 and influenza.

Collapsing Glomerulopathy Leading To Rapidly Progressive Allograft Failure From Cytomegalovirus and SARS-CoV-2 Infection With Concomitant BK Virus Nephropathy.

We present a challenging clinical case of a 68-year-old female kidney transplant recipient who had a complicated posttransplant course marked by borderline T-cell-mediated rejection and BK virus nephropathy. The treatment for borderline rejection with steroids resulted in overimmunosuppression, and the patient acquired cytomegalovirus infection manifesting as colitis and SARS-CoV-2 infection. This progressed rapidly to collapsing glomerulopathy and allograft failure. This study also highlights the challenges in surveillance with donor-derived cell-free DNA in the setting of allograft injury by multiple viral infections.

Donor Kidney With Complete Duplication of Ureter: Is It Safe for Transplantation?

Renal transplantation is the best modality of treatment for patients with end-stage renal disease. Donor shortage remains a substantial problem, for which different strategies are employed, including acceptance of marginal donors and donor kidneys with anatomic variations. We performed a successful kidney transplant of a donor kidney that had complete duplication of the ureter. After transplant, the recipient had no urinary complications.

Impact of Pulsatile Machine Perfusion on Posttransplant Recovery in Asystole Donation: Organ Optimization and the Future of Renal Transplantation.

OBJECTIVES: With the increase in life expectancy and the aging of the population, chronic kidney disease has become increasingly prevalent in our environment. Kidney transplantation remains the gold standard treatment for end-stage renal disease, but the supply of renal grafts has not been able to keep pace with growing demand. Because of this rationale, organ selection criteria have been extended (expanded criteria donation), and alternative donation types, such as donation after circulatory death, have been evaluated. These approaches aim to increase the pool of potential donors, albeit with organs of potentially lower quality. Various forms of donations, including donation after circulatory death, have also undergone assessment. This approach aims to augment the pool of potential donors, notwithstanding the compromised quality of organs associated with such methods. Diverse strategies have been explored to enhance graft function, with one of the most promising being the utilization of pulsatile machine perfusion. MATERIALS AND METHODS: We conducted a retrospective analysis on 28 transplant recipients who met the inclusion criterion of sharing the same donor, wherein one organ was preserved by cold storage and the other by pulsatile machine perfusion. We performed statistical analysis on posttransplant recovery parameters throughout the patients' hospitalization, including admission and discharge phases. RESULTS: Statistically significant differences were noted in delayed graft function (P = .04), blood transfusions requirements, and Clavien-Dindo complications. Furthermore, an overall trend of improvement in discharge parameters and hospital stay was in favor of the pulsatile machine perfusion group. CONCLUSIONS: The use of pulsatile machine perfusion as a method of renal preservation results in graft optimization, leading to earlier recovery and fewer complications compared with cold storage in the context of donation after circulatory death.

Chronological and Geographical Variations in the Incidence and Acceptance of COVID-19-Positive Donors and Outcomes Among Abdominal Transplant Patients.

INTRODUCTION: Given the importance of understanding COVID-19-positive donor incidence and acceptance, we characterize chronological and geographic variations in COVID-19 incidence relative to COVID-19-positive donor acceptance. METHODS: Data on deceased donors and recipients of liver and kidney transplants were obtained from the UNOS database between 2020 and 2023. Hierarchical cluster analysis was used to assess trends in COVID-19-positive donor incidence. Posttransplant graft and patient survival were assessed using Kaplan-Meier curves. RESULTS: From among 38 429 deceased donors, 1517 were COVID-19 positive. Fewer kidneys (72.4% vs. 76.5%, p < 0.001) and livers (56.4% vs. 62.0%, p < 0.001) were used from COVID-19-positive donors versus COVID-19-negative donors. Areas characterized by steadily increased COVID-19 donor incidence exhibit the highest transplantation acceptance rates (92.33%), followed by intermediate (84.62%) and rapidly increased (80.00%) COVID-19 incidence areas (p = 0.016). Posttransplant graft and patient survival was comparable among recipients, irrespective of donor COVID-19 status. CONCLUSIONS: Regions experiencing heightened rates of COVID-19-positive donors are associated with decreased acceptance of liver and kidney transplantation. Similar graft and patient survival is noted among recipients, irrespective of donor COVID-19 status. These findings emphasize the need for adaptive practices and unified medical consensus in navigating a dynamic pandemic.

Changes in Numbers of Glomerular Macrophages Between Two Consecutive Biopsies and the Association With Renal Transplant Graft Survival.

BACKGROUND: Macrophages are involved in kidney transplants. The aim of the study was to investigate if changes exist in the levels of glomerular macrophage index (GMI) between two consecutive kidney transplant biopsies, and if so to determine their potential impact on graft survival. METHODS: Two consecutive biopsies were performed on the same renal graft in 623 patients. GMI was categorized into three GMI classes: ≤1.8 Low, 1.9-4.5 Medium, and ≥4.6 High. This division yielded nine possible switches between the first and second biopsies (Low-Low, Low-Medium, etc.). Cox-regressions were used and hazard ratios (HR) with 95% confidence interval (CI) are presented. RESULTS: The worst graft survival was observed in the High-High group, and the best graft survival was observed in the Low-Low and High-Low groups. Compared to the High-High group, a reduction of risk was observed in nearly all other decreasing groups (reductions between 65% and 80% of graft loss). After adjustment for covariates, the risk for graft-loss was lower in the Low-Low (HR = 0.24, CI 0.13-0.46), Low-Medium (HR = 0.25, CI 0.11-0.55), Medium-Low (HR = 0.29, CI 0.11-0.77), and the High-Low GMI (HR = 0.31, CI 0.10-0.98) groups compared to the High-High group as the reference. CONCLUSIONS: GMI may change dynamically, and the latest finding is of most prognostic importance. GMI should be considered in all evaluations of biopsy findings since high or increasing GMI levels are associated with shorter graft survival. Future studies need to consider therapeutic strategies to lower or maintain a low GMI. A high GMI besides a vague histological finding should be considered as a warning sign requiring more frequent clinical follow up.

Comparison Between Black Non-Hispanic and White Non-Hispanic Simultaneous Pancreas-Kidney Transplant Candidates and Recipients.

INTRODUCTION: This study examined simultaneous pancreas-kidney transplant (SPKt) in Black and White patients to identify disparities in transplantation, days on the waitlist, and reasons for SPKt waitlist removal. METHODS: Using the United Network for Organ Sharing Standard Transplant Analysis and Research file, patients between January 1, 2009, and May 31, 2021, were included. Three cohorts (overall, SPKt recipients only, and those not transplanted) were selected using propensity score matching. Conditional logistic regression was used for categorical outcomes. Days on the waitlist were compared using negative binomial regression. RESULTS: Black patients had increased odds of receiving a  SPKt (OR, 1.25 [95% CI, 1.11-1.40], p < 0.001). White patients had increased odds of receiving a kidney-only transplant (OR 0.48 [95% CI, 0.38-0.61], p < 0.001), and specifically increased odds of receiving a living donor kidney (OR 0.34 [0.25-0.45], p < 0.001). CONCLUSION: This study found that Black patients are more likely to receive a SPKt. Results suggest that there are opportunities for additional inquiry related to patient removal from the waitlist, particularly considering White patients received or accepted more kidney-only transplants and were more likely to receive a living donor kidney-only transplant.

Effect of COVID-19 on Thrombosis Incidence and Patient Prognosis in Kidney Transplant Recipients.

BACKGROUND Thrombosis poses a grave threat to patients undergoing kidney transplants, with a heightened risk of mortality. While previous studies have established a link between COVID-19 and thrombosis, the specific association between COVID-19 and thrombosis in this patient population remains unexplored. MATERIAL AND METHODS We conducted a retrospective analysis utilizing data from 394 individuals who underwent kidney transplantation within the period of September 1, 2015, to April 1, 2023. To evaluate overall survival, we employed Kaplan-Meier analysis and utilized a logistic regression model for risk analysis. Furthermore, we developed a prediction model and assessed its accuracy through calibration curves. RESULTS Out of the 394 patients included in our study, a total of 51 individuals experienced thrombosis, resulting in 2 deaths. Our analysis revealed that COVID-19 infection significantly increased the risk of thrombosis (odds ratio [OR] 8.60, 95% confidence interval 3.13-24.74, P<0.01). Additionally, the use of cyclosporine was found to elevate the risk of death (OR 20.86, 95% CI 7.93-59.24, P<0.01) according to multifactorial analysis. Logistic models were employed to screen variables, and predictive models were constructed based on the presence of COVID-19 infection and the usage of cyclosporine. A nomogram was developed, demonstrating promising accuracy in estimating the risk of thrombosis during internal validation, with a corrected C-index of 0.869. CONCLUSIONS Our study suggests that both COVID-19 infection and the use of cyclosporine can serve as reliable predictors of thrombosis risk in patients undergoing renal transplantation. Furthermore, we developed a mortality risk prediction model based on COVID-19 in assessing thrombosis.

Components of Residential Neighborhood Deprivation and Their Impact on the Likelihood of Live-Donor and Preemptive Kidney Transplantation.

INTRODUCTION: Adults residing in deprived neighborhoods face various socioeconomic stressors, hindering their likelihood of receiving live-donor kidney transplantation (LDKT) and preemptive kidney transplantation (KT). We quantified the association between residential neighborhood deprivation index (NDI) and the likelihood of LDKT/preemptive KT, testing for a differential impact by race and ethnicity. METHODS: We studied 403 937 adults (age ≥ 18) KT candidates (national transplant registry; 2006-2021). NDI and its 10 components were averaged at the ZIP-code level. Cause-specific hazards models were used to quantify the adjusted hazard ratio (aHR) of LDKT and preemptive KT across tertiles of NDI and its 10 components. RESULTS: Candidates residing in high-deprivation neighborhoods were more likely to be female (40.1% vs. 36.2%) and Black (41.9% vs. 17.7%), and were less likely to receive both LDKT (aHR = 0.66, 95% confidence interval [CI]: 0.64-0.67) and preemptive KT (aHR = 0.60, 95% CI: 0.59-0.62) than those in low-deprivation neighborhoods. These associations differedby race and ethnicity (Black: aHRLDKT = 0.58, 95% CI: 0.55-0.62; aHRpreemptive KT = 0.68, 95% CI: 0.63-0.73; Pinteractions: LDKT < 0.001; Preemptive KT = 0.002). All deprivation components were associated with the likelihood of both LDKT and preemptive KT (except median home value): for example, higher median household income (LDKT: aHR = 1.08, 95% CI: 1.07-1.09; Preemptive KT: aHR = 1.10, 95% CI: 1.08-1.11) and educational attainments (≥high school [LDKT: aHR = 1.17, 95% CI: 1.15-1.18; Preemptive KT: aHR = 1.23, 95% CI: 1.21-1.25]). CONCLUSION: Residence in socioeconomically deprived neighborhoods is associated with a lower likelihood of LDKT and preemptive KT, differentially impacting minority candidates. Identifying and understanding which neighborhood-level socioeconomic status contributes to these racial disparities can be instrumental in tailoring interventions to achieve health equity in LDKT and preemptive KT.

Natural Killer Cell Presence in Antibody-Mediated Rejection.

Transcript analyses highlight an important contribution of natural killer (NK) cells to microvascular inflammation (MVI) in antibody-mediated rejection (ABMR), but only few immunohistologic studies have quantified their spatial distribution within graft tissue. This study included 86 kidney transplant recipients who underwent allograft biopsies for a positive donor-specific antibody (DSA) result. NK cells were visualized and quantified within glomeruli and peritubular capillaries (PTC), using immunohistochemistry for CD34 alongside CD16/T-bet double-staining. Staining results were analyzed in relation to histomorphology, microarray analysis utilizing the Molecular Microscope Diagnostic System, functional NK cell genetics, and clinical outcomes. The number of NK cells in glomeruli per mm2 glomerular area (NKglom) and PTC per mm2 cortical area (NKPTC) was substantially higher in biopsies with ABMR compared to those without rejection, and correlated with MVI scores (NKglom Spearman's correlation coefficient [SCC] = 0.55, p < 0.001, NKPTC 0.69, p < 0.001). In parallel, NK cell counts correlated with molecular classifiers reflecting ABMR activity (ABMRprob: NKglom 0.59, NKPTC 0.75) and showed a trend towards higher levels in association with high functional FCGR3A and KLRC2 gene variants. Only NKPTC showed a marginally significant association with allograft function and survival. Our immunohistochemical results support the abundance of NK cells in DSA-positive ABMR.

Effect of Donor Cigarette Smoking in Kidney Transplantation: Re-Evaluation of Long-Term Outcomes.

Cigarette smoking is a common risk factor associated with negative long-term outcomes in kidney transplant recipients. However, whether donor smoking decreases graft longevity or negatively impacts recipient survival after kidney transplantation remains unknown. Therefore, this study aims to investigate the long-term outcome in patients who received a kidney graft from a deceased smoking or non-smoking donor. A total of 580 patients were divided into two groups: patients who received a graft from a smoking donor (n = 276) and those who received a graft from a non-smoking donor (n = 304). Analysis of demographic factors showed that the non-smoking cohort was older, had more extended criteria donors and longer warm ischemia times. The primary composite endpoint of patient and graft survival was better in the smoking donor cohort when analyzed using Kaplan-Meier method but not when controlled for covariates in multivariate analyses. These findings do not support a previously reported negative impact of deceased donor smoking on kidney transplant recipients. Thus, the underlying results should not be interpreted in favor of a positive donor smoking history, but rather remind the transplant community that donor smoking should not be considered as a deciding factor in refusing an otherwise acceptable kidney graft.

Norovirus Management and Outcomes in a Multicenter Pediatric Kidney Transplant Population.

BACKGROUND: Norovirus is the most common cause of viral gastroenteritis. Studies in adult kidney recipients have documented significant morbidity associated with norovirus infection, but there are few studies in pediatric recipients. METHODS: Multicenter retrospective cohort study of pediatric kidney transplant recipients with norovirus, confirmed by stool PCR, between January 1, 2008, and December 31, 2018. Outcomes of interest included duration of diarrhea, incidence of chronic diarrhea, management strategies, and graft function. RESULTS: Forty pediatric kidney transplant recipients from four centers were identified for inclusion. Median age at transplant was 5.4 years (IQR 2.2-11.2 years), and median time post-transplant was 1.9 years (IQR 0.8-3.8 years). Median diarrheal duration was 16 days (IQR 6.0-41.5 days); 15 patients (43%) had acute diarrhea, 8 (23%) had persistent, and 12 (30%) had chronic diarrhea. Twenty-one (53%) patients developed acute kidney injury. Thirty-five (88%) patients required supplemental fluids, 8 (20%) patients underwent immunosuppression reduction for a median of 22 days, 5 (13%) were treated with nitazoxanide, and 5 (13%) received oral immunoglobulin. Acute rejection was diagnosed in 3 (8%) patients within 6 months of norovirus diagnosis. We observed no sustained decline in eGFR at 12 months after diarrhea resolution (median eGFR difference: 2.8 mL/min/1.73 m2 [IQR: -17.1, 7.4]). Of the patients in the cohort, two lost their graft at 6.8 and 30.0 months after the onset of diarrhea. CONCLUSION: Norovirus is associated with significant morbidity in pediatric kidney transplant recipients. Various treatment interventions are being employed for norovirus infection. Larger studies, both observational and interventional, are needed to determine the optimal treatment.