Identifying biochemical changes in the kidney using proton nuclear magnetic resonance in an adenine diet chronic kidney disease mouse model.

This study aimed to investigate the metabolic changes in the kidneys in a murine adenine-diet model of chronic kidney disease (CKD). Kidney fibrosis is the common pathological manifestation across CKD aetiologies. Sustained inflammation and fibrosis cause changes in preferred energy metabolic pathways in the cells of the kidney. Kidney cortical tissue from mice receiving a control or adenine-supplemented diet for 8 weeks (late inflammation and fibrosis) and 12 weeks (8 weeks of treatment followed by 4 weeks recovery) were analysed by 2D-correlated nuclear magnetic resonance spectroscopy and compared with histopathology and biomarkers of kidney damage. Tissue metabolite and lipid levels were assessed using the MestreNova software. Expression of genes related to inflammation, fibrosis, and metabolism were measured using quantitative polymerase chain reaction. Animals showed indicators of severely impaired kidney function at 8 and 12 weeks. Significantly increased fibrosis was present at 8 weeks but not in the recovery group suggesting some reversal of fibrosis and amelioration of inflammation. At 8 weeks, metabolites associated with glycolysis were increased, while lipid signatures were decreased. Genes involved in fatty acid oxidation were decreased at 8 weeks but not 12 weeks while genes associated with glycolysis were significantly increased at 8 weeks but not at 12 weeks. In this murine model of CKD, kidney fibrosis was associated with the accumulation of triglyceride and free lactate. There was an up-regulation of glycolytic enzymes and down-regulation of lipolytic enzymes. These metabolic changes reflect the energy demands associated with progressive kidney disease where there is a switch from fatty acid oxidation to that of glycolysis.

Peritoneal dialysis versus haemodialysis for people commencing dialysis.

BACKGROUND: Peritoneal dialysis (PD) and haemodialysis (HD) are two possible modalities for people with kidney failure commencing dialysis. Only a few randomised controlled trials (RCTs) have evaluated PD versus HD. The benefits and harms of the two modalities remain uncertain. This review includes both RCTs and non-randomised studies of interventions (NRSIs). OBJECTIVES: To evaluate the benefits and harms of PD, compared to HD, in people with kidney failure initiating dialysis. SEARCH METHODS: We searched the Cochrane Kidney and Transplant Register of Studies from 2000 to June 2024 using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov. MEDLINE and EMBASE were searched for NRSIs from 2000 until 28 March 2023. SELECTION CRITERIA: RCTs and NRSIs evaluating PD compared to HD in people initiating dialysis were eligible. DATA COLLECTION AND ANALYSIS: Two investigators independently assessed if the studies were eligible and then extracted data. Risk of bias was assessed using standard Cochrane methods, and relevant outcomes were extracted for each report. The primary outcome was residual kidney function (RKF). Secondary outcomes included all-cause, cardiovascular and infection-related death, infection, cardiovascular disease, hospitalisation, technique survival, life participation and fatigue. MAIN RESULTS: A total of 153 reports of 84 studies (2 RCTs, 82 NRSIs) were included. Studies varied widely in design (small single-centre studies to international registry analyses) and in the included populations (broad inclusion criteria versus restricted to more specific participants). Additionally, treatment delivery (e.g. automated versus continuous ambulatory PD, HD with catheter versus arteriovenous fistula or graft, in-centre versus home HD) and duration of follow-up varied widely. The two included RCTs were deemed to be at high risk of bias in terms of blinding participants and personnel and blinding outcome assessment for outcomes pertaining to quality of life. However, most other criteria were assessed as low risk of bias for both studies. Although the risk of bias (Newcastle-Ottawa Scale) was generally low for most NRSIs, studies were at risk of selection bias and residual confounding due to the constraints of the observational study design. In children, there may be little or no difference between HD and PD on all-cause death (6 studies, 5752 participants: RR 0.81, 95% CI 0.62 to 1.07; I2 = 28%; low certainty) and cardiovascular death (3 studies, 7073 participants: RR 1.23, 95% CI 0.58 to 2.59; I2 = 29%; low certainty), and was unclear for infection-related death (4 studies, 7451 participants: RR 0.98, 95% CI 0.39 to 2.46; I2 = 56%; very low certainty). In adults, compared with HD, PD had an uncertain effect on RKF (mL/min/1.73 m2) at six months (2 studies, 146 participants: MD 0.90, 95% CI 0.23 to 3.60; I2 = 82%; very low certainty), 12 months (3 studies, 606 participants: MD 1.21, 95% CI -0.01 to 2.43; I2 = 81%; very low certainty) and 24 months (3 studies, 334 participants: MD 0.71, 95% CI -0.02 to 1.48; I2 = 72%; very low certainty). PD had uncertain effects on residual urine volume at 12 months (3 studies, 253 participants: MD 344.10 mL/day, 95% CI 168.70 to 519.49; I2 = 69%; very low certainty). PD may reduce the risk of RKF loss (3 studies, 2834 participants: RR 0.55, 95% CI 0.44 to 0.68; I2 = 17%; low certainty). Compared with HD, PD had uncertain effects on all-cause death (42 studies, 700,093 participants: RR 0.87, 95% CI 0.77 to 0.98; I2 = 99%; very low certainty). In an analysis restricted to RCTs, PD may reduce the risk of all-cause death (2 studies, 1120 participants: RR 0.53, 95% CI 0.32 to 0.86; I2 = 0%; moderate certainty). PD had uncertain effects on both cardiovascular (21 studies, 68,492 participants: RR 0.96, 95% CI 0.78 to 1.19; I2 = 92%) and infection-related death (17 studies, 116,333 participants: RR 0.90, 95% CI 0.57 to 1.42; I2 = 98%) (both very low certainty). Compared with HD, PD had uncertain effects on the number of patients experiencing bacteraemia/bloodstream infection (2 studies, 2582 participants: RR 0.34, 95% CI 0.10 to 1.18; I2 = 68%) and the number of patients experiencing infection episodes (3 studies, 277 participants: RR 1.23, 95% CI 0.93 to 1.62; I2 = 20%) (both very low certainty). PD may reduce the number of bacteraemia/bloodstream infection episodes (2 studies, 2637 participants: RR 0.44, 95% CI 0.27 to 0.71; I2 = 24%; low certainty). Compared with HD; It is uncertain whether PD reduces the risk of acute myocardial infarction (4 studies, 110,850 participants: RR 0.90, 95% CI 0.74 to 1.10; I2 = 55%), coronary artery disease (3 studies, 5826 participants: RR 0.95, 95% CI 0.46 to 1.97; I2 = 62%); ischaemic heart disease (2 studies, 58,374 participants: RR 0.86, 95% CI 0.57 to 1.28; I2 = 95%), congestive heart failure (3 studies, 49,511 participants: RR 1.10, 95% CI 0.54 to 2.21; I2 = 89%) and stroke (4 studies, 102,542 participants: RR 0.94, 95% CI 0.90 to 0.99; I2 = 0%) because of low to very low certainty evidence. Compared with HD, PD had uncertain effects on the number of patients experiencing hospitalisation (4 studies, 3282 participants: RR 0.90, 95% CI 0.62 to 1.30; I2 = 97%) and all-cause hospitalisation events (4 studies, 42,582 participants: RR 1.02, 95% CI 0.81 to 1.29; I2 = 91%) (very low certainty). None of the included studies reported specifically on life participation or fatigue. However, two studies evaluated employment. Compared with HD, PD had uncertain effects on employment at one year (2 studies, 593 participants: RR 0.83, 95% CI 0.20 to 3.43; I2 = 97%; very low certainty). AUTHORS' CONCLUSIONS: The comparative effectiveness of PD and HD on the preservation of RKF, all-cause and cause-specific death risk, the incidence of bacteraemia, other vascular complications (e.g. stroke, cardiovascular events) and patient-reported outcomes (e.g. life participation and fatigue) are uncertain, based on data obtained mostly from NRSIs, as only two RCTs were included.

The sublingual microcirculation and frailty index in chronic kidney disease patients.

OBJECTIVE: To examine the relationship between sublingual microcirculatory measures and frailty index in those attending a kidney transplant assessment clinic. METHODS: Patients recruited had their sublingual microcirculation taken using sidestream dark field videomicroscopy (MicroScan, Micro Vision Medical, Amsterdam, the Netherlands) and their frailty index score using a validated short form via interview. RESULTS: A total of 44 patients were recruited with two being excluded due to microcirculatory image quality scores exceeding 10. The frailty index score indicated significant correlations with total vessel density (p < .0001, r = -.56), microvascular flow index (p = .004, r = -.43), portion of perfused vessels (p = .0004, r = -.52), heterogeneity index (p = .015, r = .32), and perfused vessel density (p < .0001, r = -.66). No correlation was shown between the frailty index and age (p = .08, r = .27). CONCLUSIONS: There is a relationship between the frailty index and microcirculatory health in those attending a kidney transplant assessment clinic, that is not confounded by age. These findings suggest that the impaired microcirculation may be an underlying cause of frailty.

Relationship between cortical and medullary thickness and glomerular filtration rate among living kidney donors.

The relationship between the kidney cortex and medulla is not well understood in healthy populations. This study characterised the relationship between cortical/medullary thickness and measured glomerular filtration rate (GFR) in 390 living kidney donors. A positive relationship was observed between medullary, but not cortical, thickness and GFR. We propose that this reflects a correlation between juxtamedullary nephron number and GFR.

A prospective, observational study of frailty, quality of life and dialysis in older people with advanced chronic kidney disease.

BACKGROUND: Frailty is prevalent in older people with chronic kidney disease (CKD) and robust evidence supporting the benefit of dialysis in this setting is lacking. We aimed to measure frailty and quality of life (QOL) longitudinally in older people with advanced CKD and assess the impact of dialysis initiation on frailty, QOL and mortality. METHODS: Outpatients aged ≥65 with an eGFR ≤ 20ml/minute/1.73m2 were enrolled in a prospective observational study and followed up four years later. Frailty status was measured using a Frailty Index (FI), and QOL was evaluated using the EuroQol 5D-5L instrument. Mortality and dialysis status were determined through inspection of electronic records. RESULTS: Ninety-eight participants were enrolled. Between enrolment and follow-up, 36% of participants commenced dialysis and 59% died. Frailty prevalence increased from 47% at baseline to 86% at follow-up (change in median FI = 0.22, p < 0.001). Initiating dialysis was not significantly associated with change in FI. QOL declined from baseline to follow-up (mean EQ-5D-5L visual analogue score of 70 vs 63, p = 0.034), though commencing dialysis was associated with less decline in QOL. Each 0.1 increment in baseline FI was associated with 59% increased mortality hazard (HR = 1.59, 95%CI = 1.20 to 2.12, p = 0.001), and commencing dialysis was associated with 59% reduction in mortality hazard (HR = 0.41, 95%CI = 0.20 to 0.87, p = 0.020) irrespective of baseline FI. CONCLUSIONS: Frailty increased substantially over four years, and higher baseline frailty was associated with greater mortality. Commencing dialysis did not affect the trajectory of FI but positively influenced the trajectory of QOL from baseline to follow-up. Within the limitations of small sample size, our data suggests that frail participants received similar survival benefit from dialysis as non-frail participants.

Critically important outcomes for infection in trials in kidney transplantation: An international survey of patients, caregivers, and health professionals.

BACKGROUND: Infections are a common complication following kidney transplantation, but are reported inconsistently in clinical trials. This study aimed to identify the infection outcomes of highest priority for patients/caregivers and health professionals to inform a core outcome set to be reported in all kidney transplant clinical trials. METHODS: In an international online survey, participants rated the absolute importance of 16 infections and eight severity dimensions on 9-point Likert Scales, with 7-9 being critically important. Relative importance was determined using a best-worst scale. Means and proportions of the Likert-scale ratings and best-worst preference scores were calculated. RESULTS: 353 healthcare professionals (19 who identified as both patients/caregiver and healthcare professionals) and 220 patients/caregivers (190 patients, 22 caregivers, eight who identified as both) from 55 countries completed the survey. Both healthcare professionals and patients/caregivers rated bloodstream (mean 8.4 and 8.5, respectively; aggregate 8.5), kidney/bladder (mean 7.9 and 8.4; aggregate 8.1), and BK virus (mean 8.1 and 8.6; aggregate 8.3) as the top three most critically important infection outcomes, whilst infectious death (mean 8.8 and 8.6; aggregate 8.7), impaired graft function (mean 8.4 and 8.7; aggregate 8.5) and admission to the intensive care unit (mean 8.2 and 8.3; aggregate 8.2) were the top three severity dimensions. Relative importance (best-worst) scores were consistent. CONCLUSIONS: Healthcare professionals and patients/caregivers consistently identified bloodstream infection, kidney/bladder infections, and BK virus as the three most important infection outcomes, and infectious death, admission to intensive care unit and infection impairing graft function as the three most important infection severity outcomes.

Prebiotic Supplementation in Kidney Transplant Recipients for Preventing Infections and Gastrointestinal Upset: A Randomized Controlled Feasibility Study.

OBJECTIVES: Modulating the large intestinal microbiome of kidney transplant recipients (KTRs) may reduce infectious complications. The aim of this study is to assess the feasibility of a randomized controlled trial of prebiotics in reducing infections and gastrointestinal symptoms in KTRs. (DESIGN) AND METHODS: Acute KTRs were recruited to a double-blind, placebo-controlled, randomized trial at a single kidney transplant center. Patients were provided with prebiotics or placebo for 7 weeks. The primary outcome was feasibility, defined as recruitment of ≥80% of eligible people within 6 months. Secondary outcomes included adherence and tolerability, participant retention in trial, proportions of participants providing serum and stool specimens, self-reported quality of life, gastrointestinal symptoms, and infection events. RESULTS: During the 7-week period, 72 patients met eligibility criteria, of whom 60 (83%) consented to participate (mean ± standard deviation age 53 ± 12 years; 62% males). Fifty-six (78%) participants were randomized (27 interventions and 29 controls). Although participants receiving intervention experienced reduced gastrointestinal symptoms (-0.28 [interquartile range, IQR -0.67 to 0.08] vs. -0.07 [IQR -0.27 to 0], P = .03), both control and intervention groups were similar in adherence (67% vs. 72%, P = .36), tolerability (56% vs. 62%, P = .64), quality of life (-0.2 [IQR -0.6 to 0] vs. -0.2 [IQR -0.8 to 0], P = .82), and infection events (33% vs. 34%, P = .83). Blood and stool samples were collected from ≥90% of participants in both groups. CONCLUSIONS: It is feasible to recruit and retain acute KTRs in a randomized, placebo-controlled trial examining the effect of prebiotics on infections and gastrointestinal symptoms. This study also showed that prebiotics significantly reduced gastrointestinal symptoms.

Allograft failure in kidney transplant recipients who developed kidney failure secondary to ANCA-associated vasculitis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides are uncommon causes of kidney failure. In kidney transplant recipients who developed kidney failure secondary to ANCA-associated vasculitis, disease recurrence is unlikely due to ongoing immunosuppression, and patients generally have good immunological outcomes. This study compared transplant outcomes between ANCA-associated vasculitis and other etiologies of kidney disease. All 18 901 adult kidney transplant recipients (1990-2018) were ascertained from the ANZDATA Registry. Cox proportional hazards models were used to compare allograft failure between etiologies of kidney disease. Of 254 participants whose primary disease was ANCA-associated vasculitis, 95 (37%) developed allograft failure; of those who developed graft failure, 62 (65%) died with a functioning allograft. Compared with patients with IgA nephropathy, those with ANCA-associated vasculitis had higher rates of all-cause allograft failure (HR: 1.4, 95% CI: 1.2-1.7); however, rates of death-censored allograft failure were similar (HR: 1.0, 95% CI: 0.7-1.4). The most frequent causes of death in the ANCA-vasculitis group who died with a functioning graft were infection (23%) and malignancy (36%). Kidney transplant recipients who developed kidney failure secondary to ANCA-associated vasculitis may have had a higher risk of dying due to complications of immunosuppression compared with most other causes of kidney failure; however, they also had lower risks of disease recurrence and rejection.

Characteristics of the gastrointestinal microbiota in paired live kidney donors and recipients.

BACKGROUND: There are few studies that have examined whether dysbiosis occurs in kidney donors and transplant recipients following kidney transplant surgery. AIM: To ascertain whether changes occur in the gastrointestinal microbiota of the kidney donor and recipient following kidney transplantation. METHODS: Kidney transplant recipients and their donors were prospectively enrolled in a pilot study to collect one faecal sample prior to, and another faecal sample between four to eight weeks following surgery. Gastrointestinal microbiota richness, Shannon diversity measures and functional assessments of kidney donors and recipients were analysed via metagenomic sequencing. RESULTS: The study included 12 donors (median age 56 years, 6 females) and 12 recipients (median age 51 years, 3 females). Donor microbiota showed no significant changes in gastrointestinal microbiota richness, Shannon diversity, or functional assessments before and after nephrectomy. Recipient microbiota was altered post-transplant, reflected in reductions of the mean (±SD) richness values (156 ± 46.5 to 116 ± 38.6, p = 0.002), and Shannon diversity (3.57 ± 0.49 to 3.14 ± 0.52, p = 0.007), and a dramatic increase in Roseburia spp. abundance post-transplant (26-fold increase from 0.16 ± 0.0091 to 4.6 ± 0.3; p = 0.006; FDR = 0.12). Functionally, the post-transplant microbial community shifted towards those taxa using the glycolysis pathway (1.2-fold increase; p = 0.02; FDR = 0.26) for energy metabolism, while those functions involved with reactive oxygen species degradation decreased (2.6-fold; p = 0.006; FDR = 0.14). CONCLUSION: Live donor kidney transplantation and standard care post-transplant result in significant alterations in gut microbiota richness, diversity, composition and functional parameters in kidney transplant recipients but not in their kidney donors.

A Simple Clinical Tool for Stratifying Risk of Clinically Significant CKD after Nephrectomy: Development and Multinational Validation.

BACKGROUND: Clinically significant CKD following surgery for kidney cancer is associated with increased morbidity and mortality, but identifying patients at increased CKD risk remains difficult. Simple methods to stratify risk of clinically significant CKD after nephrectomy are needed. METHODS: To develop a tool for stratifying patients' risk of CKD arising after surgery for kidney cancer, we tested models in a population-based cohort of 699 patients with kidney cancer in Queensland, Australia (2012-2013). We validated these models in a population-based cohort of 423 patients from Victoria, Australia, and in patient cohorts from single centers in Queensland, Scotland, and England. Eligible patients had two functioning kidneys and a preoperative eGFR ≥60 ml/min per 1.73 m2. The main outcome was incident eGFR <45 ml/min per 1.73 m2 at 12 months postnephrectomy. We used prespecified predictors-age ≥65 years old, diabetes mellitus, preoperative eGFR, and nephrectomy type (partial/radical)-to fit logistic regression models and grouped patients according to degree of risk of clinically significant CKD (negligible, low, moderate, or high risk). RESULTS: Absolute risks of stage 3b or higher CKD were <2%, 3% to 14%, 21% to 26%, and 46% to 69% across the four strata of negligible, low, moderate, and high risk, respectively. The negative predictive value of the negligible risk category was 98.9% for clinically significant CKD. The c statistic for this score ranged from 0.84 to 0.88 across derivation and validation cohorts. CONCLUSIONS: Our simple scoring system can reproducibly stratify postnephrectomy CKD risk on the basis of readily available parameters. This clinical tool's quantitative assessment of CKD risk may be weighed against other considerations when planning management of kidney tumors and help inform shared decision making between clinicians and patients.

Patient and center characteristics associated with kidney transplant outcomes: a binational registry analysis.

This registry-based study evaluated the contribution of center characteristics to kidney transplant outcomes in adult first kidney transplant recipients in Australia and New Zealand between 2004 and 2014. Primary outcomes were mortality and graft failure, and secondary outcomes were transplant complications. Overall, 6970 transplants from 17 centers were included. For deceased donor transplants, 5-year patient and graft survival rates varied considerably (81.0-93.9% and 72.2-88.3%, respectively). Variations in mortality and graft failure were partially reduced after adjustment for patient characteristics (1% and 20% reductions) and more markedly reduced after adjustment for center characteristics (41% and 55% reductions). For living donor transplants, 5-year patient and graft survival rates varied (89.7-100% and 79.2-96.9%, respectively). Centers with high average total ischemic times (>14 h) were associated with higher mortality for both deceased (adjusted hazard ratio [(AHR] 2.24, 95% CI 1.21-4.13) and living donor transplants (AHR 1.76, 95% CI 1.02-3.04). Small center size (<35 new kidney transplants/year) was associated with a lower hazard of mortality for living donor kidney transplants (AHR 0.48, 95% CI 0.28-0.81). No center characteristic was associated with graft failure. The appreciable variations in deceased donor kidney transplant recipient and graft survival outcomes across centers were attributable to center effects.

Perioperative antibiotics for preventing post-surgical site infections in solid organ transplant recipients.

BACKGROUND: Solid organ transplant recipients are at high risk for infections due to the complexity of surgical procedures combined with the impact of immunosuppression. No consensus exists on the role of antibiotics for surgical site infections in solid organ transplant recipients. OBJECTIVES: To assess the benefits and harms of prophylactic antimicrobial agents for preventing surgical site infections in solid organ transplant recipients. SEARCH METHODS: The Cochrane Kidney and Transplant Register of Studies was searched up to 21 April 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal, and ClinicalTrials.gov. SELECTION CRITERIA: All randomised controlled trials (RCTs) and quasi-RCTs in any language assessing prophylactic antibiotics in preventing surgical site infections in solid organ transplant recipients at any time point after transplantation. DATA COLLECTION AND ANALYSIS: Two authors independently determined study eligibility, assessed quality, and extracted data. Primary outcomes were surgical site infections and antimicrobial resistance. Other outcomes included urinary tract infections, pneumonias and septicaemia, death (any cause), graft loss, graft rejection, graft function, adverse reactions to antimicrobial agents, and outcomes identified by the Standardised Outcomes of Nephrology Group (SONG), specifically graft health, cardiovascular disease, cancer and life participation. Summary effect estimates were obtained using a random-effects model and results were expressed as risk ratios (RR) and 95% confidence intervals (CI). The quality of the evidence was assessed using the risk of bias and the GRADE approach. MAIN RESULTS: We identified eight eligible studies (718 randomised participants). Overall, five studies (248 randomised participants) compared antibiotics versus no antibiotics, and three studies (470 randomised participants) compared extended duration versus short duration antibiotics. Risk of bias was assessed as high for performance bias (eight studies), detection bias (eight studies) and attrition bias (two studies). It is uncertain whether antibiotics reduce the incidence of surgical site infections as the certainty of the evidence has been assessed as very low (RR 0.42, 95% CI 0.21 to 0.85; 5 studies, 226 participants; I2 = 25%). The certainty of the evidence was very low for all other reported outcomes (death, graft loss, and other infections). It is uncertain whether extended duration antibiotics reduces the incidence of surgical site infections in either solid organ transplant recipients (RR 1.19, 95% CI 0.58 to 2.48; 2 studies, 302 participants; I2 = 0%) or kidney-only transplant recipients (RR 0.50, 95% CI 0.05 to 5.48; 1 study, 205 participants) as the certainty of the evidence has been assessed as very low. The certainty of the evidence was very low for all other reported outcomes (death, graft loss, and other infections). None of the eight included studies evaluated antimicrobial agent adverse reactions, graft health, cardiovascular disease, cancer, life participation, biochemical and haematological parameters, intervention cost, hospitalisation length, or overall hospitalisation costs. AUTHORS' CONCLUSIONS: Due to methodological limitations, risk of bias and significant heterogeneity, the current evidence for the use of prophylactic perioperative antibiotics in transplantation is of very low quality. Further high quality, adequately powered RCTs would help better inform clinical practice.

Transplant associated infections-The role of the gastrointestinal microbiota and potential therapeutic options.

Infectious complications are common following kidney transplantation and rank in the top five causes of death in patients with allograft function. Over the last 5 years, there has been emerging evidence that changes in the gastrointestinal microbiota following kidney transplantation may play a key role in the pathogenesis of transplant-associated infections. Different factors have emerged which may disrupt the interaction between the gastrointestinal microbiota and the immune system, which may lead to infective complications in kidney transplant recipients. Over the last 5 years, there has been emerging evidence that changes in the gastrointestinal microbiota following kidney transplantation may play a key role in the pathogenesis of transplant-associated infections. This review will discuss the structure and function of the gastrointestinal microbiota, the changes that occur in the gastrointestinal microbiota following kidney transplantation and the factors underpinning these changes, how these changes may lead to transplant-associated infectious complications and potential treatments which may be instituted to mitigate this risk.

Autologous Adoptive T-cell Therapy for Recurrent or Drug-resistant Cytomegalovirus Complications in Solid Organ Transplant Recipients: A Single-arm Open-label Phase I Clinical Trial.

Background: Opportunistic infections including cytomegalovirus (CMV) are a major cause of morbidity and mortality in solid organ transplant (SOT) recipients. The recurrent and protracted use of antiviral drugs with eventual emergence of drug resistance represents a significant constraint to therapy. Although adoptive T-cell therapy has been successfully used in hematopoietic stem cell transplant recipients, its extension to the SOT setting poses a considerable challenge because of the inhibitory effects of immunosuppressive drugs on the virus-specific T-cell response in vivo and the perceived risk of graft rejection. Methods: In this prospective study, 22 SOT recipients (13 renal and 8 lung and 1 heart transplants) with recurrent or ganciclovir-resistant CMV infection were recruited, and 13 of them were treated with in vitro-expanded autologous CMV-specific T cells. These patients were monitored for safety, clinical symptoms, and immune reconstitution. Results: Autologous CMV-specific T-cell manufacture was attempted for 21 patients, and was successful in 20. The use of this adoptive immunotherapy was associated with no therapy-related serious adverse events. Eleven (84%) of the 13 treated patients showed improvement in symptoms, including complete resolution or reduction in DNAemia and CMV-associated end-organ disease and/or the cessation or reduced use of antiviral drugs. Furthermore, four of these patients showed coincident increased frequency of CMV-specific T cells in peripheral blood after completion of T-cell therapy. Conclusions: The data presented here demonstrate for the first time the clinical safety of CMV-specific adoptive T-cell therapy and its potential therapeutic benefit for SOT recipients with recurrent and/or drug-resistant CMV infection or disease. Clinical Trials Registration: ACTRN12613000981729.

Comparison of graft and patient outcomes following kidney transplantation in extended hour and conventional haemodialysis patients.

AIM: Differences in early graft function between kidney transplant recipients previously managed with either haemodialysis (HD) or peritoneal dialysis are well described. However, only two single-centre studies have compared graft and patient outcomes between extended hour and conventional HD patients, with conflicting results. METHODS: This study compared the outcomes of all extended hour (≥24 h/week) and conventional HD patients transplanted in Australia and New Zealand between 2000 and 2014. The primary outcome was delayed graft function (DGF), defined in an ordinal manner as either a spontaneous fall in serum creatinine of less than 10% within 24 h, or the need for dialysis within 72 h following transplantation. Secondary outcomes included the requirement for dialysis within 72 h post-transplant, acute rejection, estimated glomerular filtration rate at 12 months, death-censored graft failure, all-cause and cardiovascular mortality, and a composite of graft failure and mortality. RESULTS: A total of 4935 HD patients (378 extended hour HD, 4557 conventional HD) received a kidney transplant during the study period. Extended hour HD was associated with an increased likelihood of DGF compared with conventional HD (adjusted proportional odds ratio 1.33; 95% confidence interval 1.06-1.67). There was no significant difference between extended hour and conventional HD in terms of any of the secondary outcomes. CONCLUSION: Compared to conventional HD, extended hour HD was associated with DGF, although long-term graft and patient outcomes were not different.

BK Polyomavirus: Clinical Aspects, Immune Regulation, and Emerging Therapies.

BK polyomavirus (BKV) causes frequent infections during childhood and establishes persistent infections within renal tubular cells and the uroepithelium, with minimal clinical implications. However, reactivation of BKV in immunocompromised individuals following renal or hematopoietic stem cell transplantation may cause serious complications, including BKV-associated nephropathy (BKVAN), ureteric stenosis, or hemorrhagic cystitis. Implementation of more potent immunosuppression and increased posttransplant surveillance has resulted in a higher incidence of BKVAN. Antiviral immunity plays a crucial role in controlling BKV replication, and our increasing knowledge about host-virus interactions has led to the development of improved diagnostic tools and clinical management strategies. Currently, there are no effective antiviral agents for BKV infection, and the mainstay of managing reactivation is reduction of immunosuppression. Development of immune-based therapies to combat BKV may provide new and exciting opportunities for the successful treatment of BKV-associated complications.

Infectious Complications Following Kidney Transplantation-A Focus on Hepatitis C Infection, Cytomegalovirus Infection and Novel Developments in the Gut Microbiota.

The incidence of infectious complications, compared with the general population and the pre-transplant status of the recipient, increases substantially following kidney transplantation, causing significant morbidity and mortality. The potent immunosuppressive therapy given to prevent graft rejection in kidney transplant recipients results in an increased susceptibility to a wide range of opportunistic infections including bacterial, viral and fungal infections. Over the last five years, several advances have occurred that may have changed the burden of infectious complications in kidney transplant recipients. Due to the availability of direct-acting antivirals to manage donor-derived hepatitis C infection, this has opened the way for donors with hepatitis C infection to be considered in the donation process. In addition, there have been the development of medications targeting the growing burden of resistant cytomegalovirus, as well as the discovery of the potentially important role of the gastrointestinal microbiota in the pathogenesis of post-transplant infection. In this narrative review, we will discuss these three advances and their potential implications for clinical practice.

Predictors of new-onset chronic kidney disease in patients managed surgically for T1a renal cell carcinoma: An Australian population-based analysis.

BACKGROUND: New-onset chronic kidney disease (CKD) following surgical management of kidney tumors is common. This study evaluated risk factors for new-onset CKD after nephrectomy for T1a renal cell carcinoma (RCC) in an Australian population-based cohort. METHODS: There were 551 RCC patients from the Australian states of Queensland and Victoria included in this study. The primary outcome was new-onset CKD (eGFR <60 mL/min per 1.73 m2 ) and the secondary outcome was new-onset moderate-severe CKD (<45 mL/min per 1.73 m2 ). Multivariable logistic regression was used to evaluate associations between patient, tumor and health-service characteristics and these outcomes. RESULTS: Forty percent (219/551) of patients developed new-onset CKD, and 12% (68/551) experienced new-onset moderate-severe CKD. Risk factors for new-onset CKD were age, lower preoperative eGFR, tumor size >20 mm, radical nephrectomy, lower hospital caseloads (<20 cases/year), and rural place of residence. The associations between rural place of residence and low center volume were a consequence of higher radical nephrectomy rates. CONCLUSION: Risk factors for CKD after nephrectomy generally relate to worse baseline health, or likelihood of undergoing radical nephrectomy. Surgeons in rural centres and hospitals with low caseloads may benefit from formalized integration with specialist centers for continued professional development and case-conferencing, to assist in management decisions.

Indoxyl Sulfate Induces Apoptosis and Hypertrophy in Human Kidney Proximal Tubular Cells.

Indoxyl sulfate (IS) is a protein-bound uremic toxin that accumulates in patients with declining kidney function. Although generally thought of as a consequence of declining kidney function, emerging evidence demonstrates direct cytotoxic role of IS on endothelial cells and cardiomyocytes, largely through the expression of pro-inflammatory and pro-fibrotic factors. The direct toxicity of IS on human kidney proximal tubular epithelial cells (PTECs) remains a matter of debate. The current study explored the effect of IS on primary cultures of human PTECs and HK-2, an immortalized human PTEC line. Pathologically relevant concentrations of IS induced apoptosis and increased the expression of the proapoptotic molecule Bax in both cell types. IS impaired mitochondrial metabolic activity and induced cellular hypertrophy. Furthermore, statistically significant upregulation of pro-fibrotic (transforming growth factor-ß, fibronectin) and pro-inflammatory molecules (interleukin-6, interleukin-8, and tumor necrosis factor-α) in response to IS was observed. Albumin had no influence on the toxicity of IS. The results of this study suggest that IS directly induced a pro-inflammatory and pro-fibrotic phenotype in proximal tubular cells. In light of the associated apoptosis, hypertrophy, and metabolic dysfunction, this study demonstrates that IS may play a role in the progression of chronic kidney disease.