Cannabis use is associated with reduced access to kidney transplantation and an increased risk of acute rejection post-transplant.

BACKGROUND: The association between cannabis use and access to waitlisting, transplantation, and post-transplant outcomes remains uncertain. METHODS: Patients referred for kidney transplant (KT) to the University Health Network from January 1, 2003, to June 30, 2020, and followed until December 31, 2020, were included. Predictors of reported cannabis use were examined using a logistic regression model. The association between cannabis use and time to clearance for KT, undergoing KT, and post-transplant outcomes was evaluated using Cox proportional hazards models. RESULTS: Among 3734 patients, the prevalence of reported cannabis use was 11.8%. Cannabis use was associated with a lower likelihood of KT clearance (adjusted hazard ratio [aHR] .82 [95% confidence interval (CI): .72, .94]). Once cleared for KT, cannabis use did not predict the subsequent receipt of KT (aHR .92, [95% CI: .79, 1.08]). Among 2091 KT recipients, cannabis use was associated with a higher likelihood of biopsy-proven acute rejection (aHR 1.55, [95% CI: 1.06, 2.27]). The relative hazard of death-censored graft failure was similarly elevated (aHR 1.60 [95% CI: .95, 2.72]). Cannabis use did not predict total graft failure (aHR 1.33 [95% CI: .90, 1.96]), death with graft function (aHR 1.06 [95% CI: .59, 1.89]), or hospital readmission in the first-year post-transplant (aHR 1.26 [95% CI: .95, 1.68]). CONCLUSIONS: Cannabis users have less access to transplantation and an increased risk of acute rejection, possibly leading to more graft loss. Further studies are warranted to understand possible mechanisms for the increased risk of allograft immune injury among cannabis users.

Impact of early surgical complications on kidney transplant outcomes.

BACKGROUND: Kidney transplantation (KT) improves clinical outcomes of patients with end stage renal disease. Little has been reported on the impact of early post-operative surgical complications (SC) on long-term clinical outcomes following KT. We sought to determine the impact of vascular complications, urological complications, surgical site complications, and peri-graft collections within 30 days of transplantation on patient survival, graft function, and hospital readmissions. METHODS: We conducted a single-centre, observational cohort study examining adult patients (≥ 18 years) who received a kidney transplant from living and deceased donors between January 1st, 2005 and December 31st, 2015 with follow-up until December 31st, 2016 (n = 1,334). Univariable and multivariable analyses were performed with Cox proportional hazards models to analyze the outcomes of SC in the early post-operative period after KT. RESULTS: The cumulative probability of SC within 30 days of transplant was 25%, the most common SC being peri-graft collections (66.8%). Multivariable analyses showed significant relationships between Clavien Grade 1 SC and death with graft function (HR 1.78 [95% CI: 1.11, 2.86]), and between Clavien Grades 3 to 4 and hospital readmissions (HR 1.95 [95% CI: 1.37, 2.77]). CONCLUSIONS: Early SC following KT are common and have a significant influence on long-term patient outcomes.

Renal cell carcinoma in kidney transplant recipients: incidence, trends, clinical management & outcomes.

OBJECTIVE: To describe the incidence, characteristics, clinical management, and outcomes of renal cell carcinoma (RCC) among a large, single-centre cohort of kidney transplant recipients (KTR). METHODS: We conducted an observational cohort study looking at KTR transplanted between January 2000-December 2017 (n = 2443) with ≥ 1 year of follow-up. Simultaneous kidney/pancreas transplants were excluded. The Kaplan-Meier product-limit method was used to determine the incidence of RCC. Characteristics and management of RCC were examined using descriptive statistics. Risk factors and clinical outcomes were analyzed using Cox regression models. RESULTS: The incidence of RCC among our cohort was 0.32 per 100 person-years, 2.1% of all KTRs. Almost half (47.1%) of cases occurred within 4 years post-transplant. The majority of cases were T1a (86.3%), clear-cell (45.1%), and in the native kidney (80.4%). KTR diagnosed with RCC had a twofold higher incidence of other malignancies versus KTR without RCC. Overall mortality, but not cancer-specific mortality, at 2- and 5-years post-transplant was threefold higher among KTR with RCC than those without. CONCLUSIONS: Incidence of RCC among our KTR was slightly higher than the general population; majority of cases occur in the native kidneys and are low stage, low grade. Indolent histologic variants were more common than the general population. KTR with RCC had a higher incidence of other malignancies. Overall, but not cancer-specific, mortality was higher among KTRs diagnosed with RCC.

The epidemiology of early deep vein thrombosis in kidney transplant recipients.

BACKGROUND: Because kidney transplant recipients may be at increased risk for deep vein thrombosis (DVT) following transplantation, we investigated the incidence, risk factors, treatments and outcomes of early DVT among kidney transplant recipients. METHODS: An observational, single-centre cohort study was conducted among adult kidney transplant recipients from Jan. 1, 2005, to Dec. 31, 2016 with 1-year followup. Time to DVT was assessed using the Kaplan-Meier method. Cox proportional hazards and linear regression models were used to analyze risk factors for and outcomes of DVT. RESULTS: The cumulative incidence of DVT was 4.25% at 3 months after transplant. In multivariable analysis, the use of depleting induction agents (hazard ratio [HR] 2.13, 95% confidence interval [CI] 1.05-4.35]), white recipient race (HR 1.84. 95% CI 1.08-3.12), the use of kidneys from expanded criteria donors (HR 2.13, 95% CI 1.05-4.32) and lower recipient body mass index (HR 0.95, 95% CI 0.91-1.00) increased the risk for early DVT. Peritransplant DVT prophylaxis was not associated with early DVT. Early DVT was not associated with reduced graft function, death, graft failure or first hospital readmission. CONCLUSION: Risk factors for early DVT in our cohort of kidney transplant recipients included white recipient race, use of depleting agents, lower recipient body mass index and use of expanded criteria donors. As practice patterns of donor and recipient selection in kidney transplantation evolve, the results of this study may aid in perioperative risk assessments and decision-making about the use of DVT prophylaxis.

Incidence, risk factors, outcomes, and clinical management of BK viremia in the modern era of kidney transplantation.

BK viremia is endemic among kidney transplant recipients (KTRs). Incidence, risk factors, outcomes, and clinical management of detectable versus high BK viremia have not been considered previously in KTR in the modern era. This observational study examined KTR transplanted between January 1, 2009 and December 31, 2016. Any BK viral load in the serum constituted detectable BK viremia and ≥103 copies/ml constituted high viremia. Among 1193 KTRs, the cumulative probability of developing detectable and high BK viremia within 2 years posttransplant were 27.8% and 19.6%, respectively. Significant risk factors for detectable BK viremia included recipient age (HR 1.02 [95% CI: 1.01, 1.03]) and donor age (HR 1.01 [95% CI: 1.00, 1.02]). Recipient age also predicted high BK viremia (HR 1.02 [95% CI: 1.01, 1.03]), whereas White race (HR 0.70 [95% CI: 0.52, 0.95]), nondepleting induction therapy (HR 0.61 [95% CI: 0.42, 0.89]), and delayed graft function (HR 0.61 [95% CI: 0.42, 0.88]) were protective. Mean estimated glomerular filtration rates were 4.28 ml/min/1.72 m2 (95% CI: 2.71, 5.84) lower with detectable BK viremia. Although low viral load was usually not acted upon at first presentation, antiproliferative dose reductions were the most common initial management. BK viremia remains a common early complication in a modern cohort of KTRs. These findings highlight the benefit of early BKV monitoring in addition to intensive clinical management. Clinical responses beyond first positive BK viremia tests, and their implications for graft outcomes, merit further investigation.

Early postoperative acute myocardial infarction in kidney transplant recipients: A nested case-control study.

INTRODUCTION: The epidemiology of early acute myocardial infarctions after kidney transplantation has not been well characterized. This study sought to examine the incidence, risk factors, and clinical outcomes of early acute myocardial infarctions or EAMI in kidney transplant recipients. METHODS: A total of 1976 patients who underwent kidney transplantation at our center from Jan 1, 2000, to Sept 30, 2016, were included. A nested case-control design was used to study EAMI risk factors using a conditional logistic regression model. A Cox proportional hazards model was used to assess the association of EAMI with death-censored graft failure, death with graft function, and total graft failure. RESULTS: Seventy four patients had an EAMI within 3 months post-transplant. Based on univariable analyses, risk factors for EAMI included age and recipient history of diabetes mellitus or coronary artery disease. After adjustment, recipient history of coronary artery disease was the only independent predictor for EAMI (OR 3.76, p < .001). Patients who experienced EAMI were more likely to experience death-censored graft failure, death with graft function, and total graft failure. CONCLUSION: While the incidence of EAMI in kidney transplant recipients is relatively low, these data show that EAMI has profound long-term effects on morbidity and mortality.

Engaging high school students about organ donation and transplantation: an evaluation of the High School Outreach Initiative (HSOI) program.

Adolescents can be influential in changing societal perceptions of organ donation and transplantation (ODT) but current studies on youth are limited. We sought to (1) assess the baseline knowledge in ODT among students in Toronto, Canada, and (2) evaluate the effectiveness of the High School Outreach Initiative (HSOI) program presentations in changing awareness and interest about ODT. Pre- and post-presentation surveys were administered to high school students about their knowledge of ODT, awareness of donor registration, importance of donation, intent to register, and willingness to talk to their families about donation. Descriptive statistics were used to characterize the students' baseline knowledge and interest. Wilcoxon and McNemar tests were used to analyze changes in perceptions before and after the presentation. A total of 449 HSOI presentations were delivered to 33,090 students at 102 high schools in the Greater Toronto Area between 2012 and 2019. Data from 3327 surveys completed by students before a presentation showed 46.5% were not knowledgeable about ODT. For the 2-year period between 2017 and 2019, 1224 matched pre- and post-presentation surveys were collected. The 49.8% of students who stated they were not knowledgeable about ODT prior to the presentation decreased to 3.8% after (p < 0.001). Those who were not willing to register decreased by half after the presentation (p < 0.001). The HSOI is an effective educational program in improving youth's attitudes and perceptions toward ODT. Further directions of the program include the expansion to other cities and the collection of demographic information of students.

Lymphoceles: impact on kidney transplant recipients, graft, and healthcare system.

INTRODUCTION: Following kidney transplantation, lymphoceles can impact patient and graft outcomes, while resulting in significant hospital resource utilization. We aimed to characterize the incidence, risk factors, outcomes, and clinical management of lymphoceles among kidney transplant recipients and review impact on health system utilization at a high-volume center. MATERIALS AND METHODS: We conducted a single-center, observational cohort study on adults transplanted between January 1, 2005 and December 31, 2017. Incidence, risk factors, and clinical outcomes were assessed using the Kaplan-Meier product-limit method, multivariable logistic regression model, and Cox proportional hazards model, respectively. RESULTS: Lymphoceles developed in 72 of 1881 patients (3.8%). Multivariate analysis demonstrated that a longer time on dialysis before transplant [HR 1.09 (95% CI: 1.02, 1.17)], laparoscopic donor nephrectomy [HR 2.31 (95% CI: 1.04, 5.12)], and depleting induction therapy [HR 0.39 (95% CI: 0.18, 0.87)] were significant risk factors for lymphocele development. Lymphoceles independently increased the likelihood of hospital readmission [HR 3.96 (95% CI: 2.99, 5.25)] but had no significant effect on the likelihood of graft failure or death with graft function. Of 72 cases, 44 received a radiological or surgical intervention. Fifteen of 44 lymphoceles required further intervention due to re-accumulation or complications. CONCLUSION: Patients with longer dialysis times, kidneys from laparoscopic donor nephrectomy, and depleting induction therapy were associated with an increased risk for developing symptomatic lymphoceles. Our center's treatment for symptomatic lymphoceles did not result in significant graft dysfunction, but significantly higher healthcare resource utilization was noted.

Extracellular Matrix Injury of Kidney Allografts in Antibody-Mediated Rejection: A Proteomics Study.

BACKGROUND: Antibody-mediated rejection (AMR) accounts for >50% of kidney allograft loss. Donor-specific antibodies (DSA) against HLA and non-HLA antigens in the glomeruli and the tubulointerstitium cause AMR while inflammatory cytokines such as TNFα trigger graft injury. The mechanisms governing cell-specific injury in AMR remain unclear. METHODS: Unbiased proteomic analysis of laser-captured and microdissected glomeruli and tubulointerstitium was performed on 30 for-cause kidney biopsy specimens with early AMR, acute cellular rejection (ACR), or acute tubular necrosis (ATN). RESULTS: A total of 107 of 2026 glomerular and 112 of 2399 tubulointerstitial proteins was significantly differentially expressed in AMR versus ACR; 112 of 2026 glomerular and 181 of 2399 tubulointerstitial proteins were significantly dysregulated in AMR versus ATN (P<0.05). Basement membrane and extracellular matrix (ECM) proteins were significantly decreased in both AMR compartments. Glomerular and tubulointerstitial laminin subunit γ-1 (LAMC1) expression decreased in AMR, as did glomerular nephrin (NPHS1) and receptor-type tyrosine-phosphatase O (PTPRO). The proteomic analysis revealed upregulated galectin-1, which is an immunomodulatory protein linked to the ECM, in AMR glomeruli. Anti-HLA class I antibodies significantly increased cathepsin-V (CTSV) expression and galectin-1 expression and secretion in human glomerular endothelial cells. CTSV had been predicted to cleave ECM proteins in the AMR glomeruli. Glutathione S-transferase ω-1, an ECM-modifying enzyme, was significantly increased in the AMR tubulointerstitium and in TNFα-treated proximal tubular epithelial cells. CONCLUSIONS: Basement membranes are often remodeled in chronic AMR. Proteomic analysis performed on laser-captured and microdissected glomeruli and tubulointerstitium identified early ECM remodeling, which may represent a new therapeutic opportunity.

Surgical site complications in kidney transplant recipients: incidence, risk factors and outcomes in the modern era.

BACKGROUND: Surgical site complications (SSCs) are an important source of morbidity after kidney transplantation. We assessed the incidence, risk factors, outcomes and economic impact of SSCs in a large, diverse population of kidney transplant recipients. METHODS: We conducted a single-centre, observational cohort study of adult (age ≥ 18 yr) patients who underwent kidney transplantation between Jan. 1, 2005, and Dec. 31, 2015, with a minimum of 1 year of follow-up. Cases of SSC, including infections and wound dehiscence, were determined from patient records. Inpatient and outpatient hospital costs were determined 6 and 12 months after transplantation. We used the Kaplan-Meier product-limit method to determine the cumulative probability of SSCs and other outcomes. We evaluated risk factors and clinical outcomes using Cox proportional hazard ratios. Linear regression models were used to study the effect of SSCs on graft function. RESULTS: The incidence rate of SSCs within 30 days after transplantation was 4.19 per 100 person-months. The cumulative probability of developing an SSC within 30 days after transplantation was 4.13% (95% confidence interval [CI] 3.23%-5.28%). Increased recipient body mass index (BMI) (hazard ratio [HR] 1.07, 95% CI 1.02-1.11), longer cold ischemic time (HR 1.05, 95% CI 1.01-1.09) and transplantation in 2010-2012 versus 2005-2009 (HR 2.20, 95% CI 1.19-4.04) were risk factors for SSC development. In multivariable stepwise Cox proportional hazard models, SSC was a significant risk factor for death-censored graft failure (HR 3.08, 95% CI 1.60-5.90) and total graft failure (HR 2.09, 95% CI 1.32-3.32). Cumulative median hospital costs were $2238.46 greater for patients with an SSC than for those without. CONCLUSION: Increased BMI, longer cold ischemic time and the 2010-2012 transplantation period predisposed to SSCs. The development of SSCs was associated with a higher risk of graft failure. Strategies to minimize SSCs may improve outcomes after kidney transplantation and reduce costs.

Evaluation of a professional development course on research methods for healthcare professionals.

Healthcare is constantly evolving and thus requires lifelong learning. Evidence-based learning has been shown to lead to better patient outcomes, yet many healthcare professionals report gaps in their research abilities. We sought to evaluate the efficacy of a professional development program in addressing identified gaps.

Donor kidney volume measured by computed tomography is a strong predictor of recipient eGFR in living donor kidney transplantation.

PURPOSE: The effect of living donor kidney allograft size on recipient outcomes is not well understood. In this study, we sought to investigate the relationship between preoperatively measured donor kidney volume and recipient estimated glomerular filtration rate (eGFR) in living donor kidney transplantation (LDKT). METHODS: We studied computed tomography (CT) donor kidney volumes and recipient outcomes for 438 LDKTs at the Toronto General Hospital between 2007 and 2016. Estimated glomerular filtration rate (eGFR) was calculated at 1, 3, and 6 months and a multivariable linear regression model was fitted to study the effect of donor kidney volume on recipient eGFR. RESULTS: The mean volume and weight of the donated kidneys were 157.3 (± 32.3) cc and 186.7 (± 48.7) g, respectively. Kidney volume was significantly associated with eGFR on multivariable analysis (P < 0.001). Specifically, for every 10 cc increase in kidney volume, there was a 1.68 mL/min, 1.25 mL/min and 0.97 mL/min rise in recipient eGFR at 1, 3, and 6 months, respectively. CONCLUSIONS: Donor kidney volume is a strong independent predictor of recipient eGFR in LDKT, and therefore, may be a valuable addition to predictive models of eGFR after transplant. Further research may determine if the inclusion of donor kidney volume in matching algorithms can improve recipient outcomes.

Substance use in kidney transplant candidates and its impact on access to kidney transplantation.

BACKGROUND: Due to the increasing public acceptance of substance use, it is important to understand the association between substance use and access to kidney transplant and its outcomes. Here, we assess the sociodemographic predictors of substance use and the association between substance use and KT access. METHODS: Predictors of substance use were examined using a multivariable-adjusted multinomial logistic regression. The association between current substance use (tobacco and drug) and time from referral to listing or receipt of a KT was examined using Cox proportional hazards models. RESULTS: Of 2346 patients, the prevalence of current substance use was 17%. Predictors of current tobacco use were younger age, male sex, Caucasian ethnicity, being unemployed, and unmarried. Predictors of current drug use were younger age, male sex, Caucasian ethnicity, a history of non-adherence, and a history of mental health disorder. Patients with tobacco use had a decreased likelihood of being cleared for KT (hazard ratio [HR]:0.83[0.70, 0.99]) and receiving a KT (HR:0.80 [0.66, 0.96]). No association was seen in this sample for patients with drug use (HR:0.88 [0.69, 1.11] for being cleared for KT and 0.88 [0.69, 1.14] for KT, respectively). CONCLUSIONS: Tobacco use was associated with a decreased likelihood of access to KT whereas there was no statistically significant difference in access to KT between patients with or without drug use.

Bacteremia in kidney transplant recipients: Burden, causes, and consequences.

Bacteremia is an important complication after kidney transplantation. We examined bacteremia and its outcomes in a large cohort of kidney transplant recipients. Kidney transplants from 1-Jul-2004 to 1-Dec-2014 at the Toronto General Hospital were eligible for study inclusion. Bacteremia was defined as two blood culture positives for common skin contaminants or one blood culture positive for other organisms. The cumulative incidence of first bacteremia was estimated using the Kaplan-Meier method, and risk factors were examined in a Cox proportional hazards model. The risk of graft failure or death was assessed in a time-dependent Cox model. Over follow-up, 154 of 1333 patients had at least one bacteremia episode. The cumulative incidence of first bacteremia was 6.8% (6 months) and 11.9% (5 years). Risk factors included recipient diabetes mellitus, time on dialysis, dialysis modality, delayed graft function, donor age, and donor eGFR. Bacteremia increased the risk of total graft failure (hazard ratio 2.11 [95% CI: 1.50, 2.96]), death-censored graft failure (1.73 [0.99, 3.02]), and death with graft function (2.52 [1.63, 3.89]). In conclusion, bacteremia is common after kidney transplantation and impacts both graft and patient survival. Identifying high-risk patients for targeted preventive strategies may reduce the burden and adverse consequences of this important complication.

Ethnic background is associated with no live kidney donor identified at the time of first transplant assessment-an opportunity missed? A single-center retrospective cohort study.

Patients from ethnocultural minorities have reduced access to live donor kidney transplant (LDKT). To explore early pretransplant ethnocultural disparities in LDKT readiness, and the impact of the interactions with the transplant program, we assessed if patients had a potential live donor (LD) identified at first pretransplant assessment, and if patients with no LD initially received LDKT subsequently. Single-center, retrospective cohort of adults referred for kidney transplant (KT) assessment. Multivariable logistic regression assessed the association between ethnicity and having a potential LD. Cox proportional hazard analysis assessed the association between no potential LD initially and subsequent LDKT. Of 1617 participants, 66% of Caucasians indicated having a potential LD, compared with 55% of South Asians, 44% of African Canadians, and 41% of East Asians (P < 0.001). In multivariable logistic regression analysis, the odds of having a potential LD identified was significantly lower for African, East and South Asian Canadians. No potential LD at initial KT assessment was associated with lower likelihood of LDKT subsequently (hazard ratio [HR], 0.14; [0.10-0.19]). Compared to Caucasians, African, East and South Asian and African Canadians are less likely to have a potential LD identified at first KT assessment, which predicts a lower likelihood of subsequent LDKT.

Standardization and alignment of data capture practices to clinical processes in the evaluation of living kidney donor candidates.

The Living Kidney Donation Program at the Toronto General Hospital, University Health Network sought to develop a comprehensive, secure, accurate, and up-to-date information system for the purposes of quality improvement, research, and performance evaluation. The Comprehensive Living Kidney Donor Database (CLiKeD) houses comprehensive demographic, medical, psychosocial, and evaluation data on living kidney donor candidates abstracted from multiple health information sources. Data are routinely audited to ensure high data quality. Over 3,500 living kidney donor candidates are currently included in CLiKeD. The development of this data system will allow for regular performance assessments of the program, implementation of quality improvement initiatives, and the completion of high-impact, clinically relevant research. In addition, the conception and development of CLiKeD has been instrumental in improving documentation of personal health information at the point of care.

Incidence and Risk Factors for Leukopenia in Kidney Transplant Recipients Receiving Valganciclovir for Cytomegalovirus Prophylaxis.

CONTEXT: Valganciclovir is used not only for cytomegalovirus prophylaxis after kidney transplantation but can also induce leukopenia, thereby making patients more susceptible to other infections. The epidemiology of leukopenia in patients on valganciclovir remains poorly understood. OBJECTIVE: To determine the incidence and risk factors for leukopenia in patients receiving valganciclovir for cytomegalovirus prophylaxis after kidney transplantation. METHODS: In this single-center, retrospective, cohort study, we included kidney recipients transplanted from January 1, 2003, to December 31, 2010, to determine the incidence and risk factors for leukopenia in patients who received valganciclovir for cytomegalovirus prophylaxis. The Kaplan-Meier product limit method was used to graphically assess time to leukopenia, and risk factors were assessed using Cox proportional hazards models. RESULTS: A total of 542 kidney transplant recipients were included in the study cohort. The cumulative incidence of leukopenia at 6 months posttransplant was 39.3% (11.0% for neutropenia). Low baseline white blood cell count (hazard ratio [HR] 2.34 [95% confidence interval [CI], 1.37-4.00]) and high baseline body mass index (HR 1.05 [95% CI, 1.02-1.09]) were independently associated with an increased risk of leukopenia, while higher Cockcroft-Gault creatinine clearance (HR 0.87 [95% CI, 0.78-0.97]) was significantly associated with a decreased risk of leukopenia. CONCLUSIONS: These data suggest that recipient baseline white blood cell count, baseline body mass index, and kidney function are clinical predictors of new-onset leukopenia after kidney transplantation. Our results may inform the approach to cytomegalovirus prophylaxis to reduce the risk of valganciclovir-induced leukopenia in kidney transplant recipients.

Postoperative surgical-site hemorrhage after kidney transplantation: incidence, risk factors, and outcomes.

Studies investigating the incidence, risk factors, and outcomes of surgical-site hemorrhage after kidney transplantation are limited. Patients who underwent a kidney transplant from 1 January 2000 to 30 September 2012 (followed until 31 December 2012) at Toronto General Hospital were included in this study. Postoperative surgical-site hemorrhage was defined as a drop in hemoglobin ≥20 g/l over a 24-hour period within 3 days of transplantation, followed by an ultrasound indicating a significant hematoma/collection. A total of 59 of 1203 (4.9%) kidney transplant recipients had postoperative surgical-site hemorrhage. Most cases (89.8%) occurred within 1 day after transplantation. Living donor transplants [OR 0.30 (95% CI: 0.16, 0.55)] and higher recipient BMI [OR 0.54 per 10 kg/m2 increase in BMI (95% CI: 0.30, 0.99)] were associated with a significantly lower risk of bleeding. Chronic preoperative anticoagulant usage led to an increased risk of bleeding but was not statistically significant [OR 1.75 (95% CI: 0.52, 5.88)]. Postoperative hemorrhage was associated with a higher risk of graft loss or death [HR 1.62 (95% CI: 1.01, 2.60)]. While the incidence of postoperative surgical-site hemorrhage in kidney transplantation is relatively low, it may be associated with an increased risk of graft loss or death.

Hypomagnesemia and the Risk of New-Onset Diabetes Mellitus after Kidney Transplantation.

Several studies suggest a link between post-transplant hypomagnesemia and new-onset diabetes after transplantation (NODAT), but this relationship remains controversial. We conducted a retrospective cohort study of 948 nondiabetic kidney transplant recipients from January 1, 2000, to December 31, 2011, to examine the association between serum magnesium level and NODAT. Multivariable Cox proportional hazards models were fitted to evaluate the risk of NODAT as a function of baseline (at 1 month), time-varying (every 3 months), and rolling-average (i.e., mean for 3 months moving at 3-month intervals) serum magnesium levels while adjusting for potential confounders. A total of 182 NODAT events were observed over 2951.2 person-years of follow-up. Multivariable models showed an inverse relationship between baseline serum magnesium level and NODAT (hazard ratio [HR], 1.24 per 0.1 mmol/L decrease; 95% confidence interval [95% CI], 1.05 to 1.46; P=0.01). The association with the risk of NODAT persisted in conventional time-varying (HR, 1.32; 95% CI, 1.14 to 1.52; P<0.001) and rolling-average models (HR, 1.34; 95% CI, 1.13 to 1.57; P=0.001). Hypomagnesemia (serum magnesium <0.74 mmol/L) also significantly associated with increased risk of NODAT in baseline (HR, 1.58; 95% CI, 1.07 to 2.34; P=0.02), time-varying (HR, 1.78; 95% CI, 1.29 to 2.45; P<0.001), and rolling-average models (HR, 1.83; 95% CI, 1.30 to 2.57; P=0.001). Our results suggest that lower post-transplant serum magnesium level is an independent risk factor for NODAT in kidney transplant recipients. Interventions targeting serum magnesium to reduce the risk of NODAT should be evaluated.

CT volumetry is superior to nuclear renography for prediction of residual kidney function in living donors.

Living kidney donor evaluation commonly includes nuclear renography to assess split kidney function and computed tomography (CT) scan to evaluate anatomy. To streamline donor workup and minimize exposure to radioisotopes, we sought to assess the feasibility of using proportional kidney volume from CT volumetry in lieu of nuclear renography. We examined the correlation between techniques and assessed their ability to predict residual postoperative kidney function following live donor nephrectomy. In a cohort of 224 live kidney donors, we compared proportional kidney volume derived by CT volumetry with split kidney function derived from nuclear renography and found only modest correlation (left kidney R(2) =26.2%, right kidney R(2) =26.7%). In a subset of 88 live kidney donors with serum creatinine measured 6 months postoperatively, we compared observed estimated glomerular filtration rate (eGFR) at 6 months with predicted eGFR from preoperative imaging. Compared to nuclear renography, CT volumetry more closely approximated actual observed postoperative eGFR for Chronic Kidney Disease Epidemiology Collaboration (J-test: P=.02, Cox-Pesaran test: P=.01) and Mayo formulas (J-test: P=.004, Cox-Pesaran test: P<.001). These observations support the use of CT volumetry for estimation of split kidney function in healthy individuals with normal kidney function and morphology.