Disparities in Deceased Donor Kidney Offer Acceptance: A Survey of Canadian Transplant Nephrologists, General Surgeons and Urologists

Background

Significant variability in organ acceptance thresholds have been demonstrated across the United States, but data regarding the rate and rationale for kidney donor organ decline in Canada are lacking.

Objective

To examine decision making regarding deceased kidney donor acceptance and non-acceptance in a population of Canadian transplant professionals.

Design

A survey study of theoretical deceased donor kidney cases of increasing complexity.

Setting

Canadian transplant nephrologists, urologists, and surgeons making donor call decisions responding to an electronic survey between July 22 and October 4, 2022.

Participants

Invitations to participate were distributed to 179 Canadian transplant nephrologists, surgeons, and urologists through e-mail. Participants were identified by contacting each transplant program and requesting a list of physicians who take donor call.

Measurements

Survey respondents were asked whether they would accept or decline a given donor, assuming there was a suitable recipient. They were also asked to cite reasons for donor non-acceptance.

Methods

Donor scenario-specific acceptance rates (total acceptance divided by total number of respondents for a given scenario and overall) and reasons for decline were determined and presented as a percentage of the total cases declined.

Results

In all, 72 respondents from 7 provinces completed at least one question of the survey, with considerable variability between acceptance rates for centers; the most conservative center declined 60.9% of donor cases, whereas the most aggressive center declined only 28.1%, P-value < .001. There was an increased risk of non-acceptance with advancing age, donation after cardiac death, acute kidney injury, chronic kidney disease, and comorbidities.

Limitations

As with any survey, there is the potential for participation bias. In addition, this study examines donor characteristics in isolation, however, asks respondent to assume there is a suitable candidate available. In reality, whenever donor quality is considered, it should be considered in the context of the intended recipient.

Conclusion

In a survey of increasingly medically complex deceased kidney donor cases, there was significant variability in donor decline among Canadian transplant specialists. Given relatively high rates of donor decline and apparent heterogeneity in acceptance decisions, Canadian transplant specialists may benefit from additional education regarding the benefits achieved from even medically complex kidney donors for appropriate candidates relative to remaining on dialysis on the transplant waitlist.

Severity of COVID-19 among solid organ transplant recipients in Canada, 2020–2021: a prospective, multicentre cohort study

Background:

Severe COVID-19 appears to disproportionately affect people who are immunocompromised, although Canadian data in this context are limited. We sought to determine factors associated with severe COVID-19 outcomes among recipients of organ transplants across Canada.

Methods:

We performed a multicentre, prospective cohort study of all recipients of solid organ transplants from 9 transplant programs in Canada who received a diagnosis of COVID-19 from March 2020 to November 2021. Data were analyzed to determine risk factors for oxygen requirement and other metrics of disease severity. We compared outcomes by organ transplant type and examined changes in outcomes over time. We performed a multivariable analysis to determine variables associated with need for supplemental oxygen.

Results:

A total of 509 patients with solid organ transplants had confirmed COVID-19 during the study period. Risk factors associated with needing (n = 190), compared with not needing (n = 319), supplemental oxygen included age (median 62.6 yr, interquartile range [IQR] 52.5–69.5 yr v. median 55.5 yr, IQR 47.5–66.5; p < 0.001) and number of comorbidities (median 3, IQR 2–3 v. median 2, IQR 1–3; p < 0.001), as well as parameters associated with immunosuppression. Recipients of lung transplants (n = 48) were more likely to have severe disease with a high mortality rate (n = 15, 31.3%) compared with recipients of other organ transplants, including kidney (n = 48, 14.8%), heart (n = 1, 4.4%), liver (n = 9, 11.4%) and kidney–pancreas (n = 3, 12.0%) transplants (p = 0.02). Protective factors against needing supplemental oxygen included having had a liver transplant and receiving azathioprine. Having had 2 doses of SARS-CoV-2 vaccine did not have an appreciable influence on oxygen requirement. Multivariable analysis showed that older age (odds ratio [OR] 1.04, 95% confidence interval [CI] 1.02–1.07) and number of comorbidities (OR 1.63, 95% CI 1.30–2.04), among other factors, were associated with the need for supplemental oxygen. Over time, disease severity did not decline significantly.

Interpretation:

Despite therapeutic advances and vaccination of recipients of solid organ transplants, evidence of increased severity of COVID-19, in particular among those with lung transplants, supports ongoing public health measures to protect these at-risk people, and early use of COVID-19 therapies for recipients of solid organ transplants.

Outcomes of SARS-CoV-2 Infection in Unvaccinated Compared With Vaccinated Solid Organ Transplant Recipients: A Propensity Matched Cohort Study

BACKGROUND

Solid organ transplant (SOT) recipients are at high risk for complications from coronavirus disease 2019 (COVID-19). Vaccination may mitigate this risk; however, immunogenicity appears to be significantly impaired, with reports of increased risk of breakthrough infection. It is unknown if vaccine breakthrough infections are milder or as severe as infections in unvaccinated patients.

METHODS

We performed a multicenter matched cohort study between March 2020 and September 2021 to assess influence of COVID-19 vaccination on outcomes of COVID-19 infection. Treatment characteristics and disease severity outcomes were compared on the basis of vaccine status; breakthrough infections versus unvaccinated infections. Variable ratio propensity score matching based on age, sex, transplant type, and number of comorbidities, was used to develop the analytic cohort. Logistic regression was used to assess the influence of vaccination status on the selected outcomes.

RESULTS

From a cohort of 511 SOT patients with COVID-19, we matched 77 partially or fully vaccinated patients with 220 unvaccinated patients. Treatment characteristics including use of dexamethasone, remdesivir, and antibiotics did not differ. Vaccinated participants were more likely to receive tocilizumab, 15 of 77 (19.5%) versus 5 of 220 (2.3%), P  < 0.001. Disease severity outcomes including oxygen requirement, mechanical ventilation, and mortality were similar among medically attended vaccine breakthroughs compared with unvaccinated patients.

CONCLUSIONS

SOT recipients who develop medically attended COVID-19 following 1- or 2-dose vaccination seem to have similar disease severity to unvaccinated patients who develop infection. This is consistent with the requirement that SOT recipients need 3 or more vaccine doses and emphasizes the importance of alternate strategies for this population.

Waitlisted and Transplant Patient Perspectives on Expanding Access to Deceased-Donor Kidney Transplant: A Qualitative Study

Background:

A concerning number of kidneys (eg, expanded donor criteria, extended criteria, or marginal kidneys) are discarded yearly while patients experience significant morbidity and mortality on the transplant waitlist. Novel solutions are needed to solve the shortage of kidneys available for transplant. Patient perceptions regarding the use of these less than ideal kidneys remain unexplored.

Objective:

To explore the perspectives of patients who have previously received a less than ideal kidney in the past and patients awaiting transplant who could potentially benefit from one.

Design:

Qualitative description study.

Setting:

2 provinces in Canada participated (Saskatchewan and Manitoba).

Patients:

Patients with end-stage kidney disease who were awaiting kidney transplant and were either (a) aged 65 years and older, or (b) 55 years and older with other medical conditions (eg, diabetes).

Methods:

Criterion sampling was used to identify participants. Semi-structured, one-on-one interviews were conducted virtually, which explored perceived quality of life, perceptions of less than ideal kidneys, risk tolerance for accepting one, and educational needs to make such a choice. The interviews were transcribed verbatim and thematic analysis was used to analyze the data.

Results:

15 interviews were conducted with usable data (n = 10 pretransplant; n = 5 posttransplant). Participants were a mean of 65.5 ± 8.8 years old. Four interrelated themes became prominent including (1) patient awareness and understanding of their situation or context, (2) a desire for information, (3) a desire for freedom from dialysis, and (4) trust. Subthemes of transparency, clarity, standardization, and autonomy were deemed important for participant education. The majority of pretransplant participants (n = 8/10) indicated that between 3 and 5 years off of dialysis would make the risk of accepting a less than ideal kidney feel worthwhile.

Limitation:

The study setting was limited to 2 Canadian provinces, which limits the generalizability. Furthermore, the participants were homogenous in demographics such as ethnicity.

Conclusion:

These findings indicate that patients are comfortable to accept a less than ideal kidney for transplant in situations where their autonomy is respected, they are provided clear, standardized, and transparent information, and when they trust their physician. These results will be used to inform the development of a new national registry for expanding access to deceased-donor kidney transplant.

Trial Registration:

Not registered.

Immunosuppressant Medication Use in Patients with Kidney Allograft Failure: A Prospective Multi-Center Canadian Cohort Study

Background: Patients with kidney transplant failure have a high risk of hospitalization and death due to infection. The optimal use of immunosuppressants after transplant failure remains uncertain and clinical practice varies widely. Methods: This prospective cohort study enrolled patients within 21 days of starting dialysis after transplant failure in 16 Canadian centers. Immunosuppressant medication use, death, hospitalized infection, rejection of the failed allograft, and panel reactive anti-HLA antibodies (PRA) were determined at 1, 3, 6 , and 12 months and bi-annually until death, repeat transplantation, or loss to follow-up. Results: The 269 study patients were followed for a median of 558 days. There were 33 deaths, 143 patients hospitalized for infection, and 21 rejections. Most patients (65%) continued immunosuppressants, 20% continued prednisone only, while 15% discontinued all immunosuppressants. In multivariable models, patients who continued immunosuppressants had a lower risk of death (HR =0.40, 95% CI, 0.17-0.93) and were not at increased risk of hospitalized infection (HR 1.81; 95% CI 0.82 to 4.0) compared to patients who discontinued all immunosuppressants or continued prednisone only. The mean class I and class II PRA increased from 11% to 27% and 25% to 47%, respectively, but did not differ by immunosuppressant use. Continuation of immunosuppressants was not protective of rejection of the failed allograft (HR 0.81, 95% CI, 0.22-2.94). Conclusions: Prolonged use of immunosuppressants greater than one year after transplant failure was not associated with a higher risk of death or hospitalized infection but was insufficient to prevent higher anti-HLA antibodies or rejection of the failed allograft.

Clinical Practice Guideline for Solid Organ Donation and Transplantation During the COVID-19 Pandemic

The coronavirus 2019 (COVID-19) pandemic has disrupted health systems worldwide, including solid organ donation and transplantation programs. Guidance on how best to screen patients who are potential organ donors to minimize the risks of COVID-19 as well as how best to manage immunosuppression and reduce the risk of COVID-19 and manage infection in solid organ transplant recipients (SOTr) is needed.

METHODS

Iterative literature searches were conducted, the last being January 2021, by a team of 3 information specialists. Stakeholders representing key groups undertook the systematic reviews and generation of recommendations using a rapid response approach that respected the Appraisal of Guidelines for Research and Evaluation II and Grading of Recommendations, Assessment, Development and Evaluations frameworks.

RESULTS

The systematic reviews addressed multiple questions of interest. In this guidance document, we make 4 strong recommendations, 7 weak recommendations, 3 good practice statements, and 3 statements of "no recommendation."

CONCLUSIONS

SOTr and patients on the waitlist are populations of interest in the COVID-19 pandemic. Currently, there is a paucity of high-quality evidence to guide decisions around deceased donation assessments and the management of SOTr and waitlist patients. Inclusion of these populations in clinical trials of therapeutic interventions, including vaccine candidates, is essential to guide best practices.

A RAND-Modified Delphi on Key Indicators to Measure the Efficiency of Living Kidney Donor Candidate Evaluations

BACKGROUND AND OBJECTIVES

Many patients, providers, and potential living donors perceive the living kidney donor evaluation process to be lengthy and difficult to navigate.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We sought consensus on key terms and process and outcome indicators that can be used to measure how efficiently a transplant center evaluates persons interested in becoming a living kidney donor. Using a RAND-modified Delphi method, 77 participants (kidney transplant recipients or recipient candidates, living kidney donors or donor candidates, health care providers, and health care administrators) completed an online survey to define the terms and indicators. The definitions were then further refined during an in-person meeting with ten stakeholders.

RESULTS

We identified 16 process indicators (e.g., average time to evaluate a donor candidate), eight outcome indicators (e.g., annual number of preemptive living kidney donor transplants), and two measures that can be considered both process and outcome indicators (e.g., average number of times a candidate visited the transplant center for the evaluation). Transplant centers wishing to implement this set of indicators will require 22 unique data elements, all of which are either readily available or easily collected prospectively.

CONCLUSIONS

We identified a set of indicators through a consensus-based approach that may be used to monitor and improve the performance of a transplant center in how efficiently it evaluates persons interested in becoming a living kidney donor.

Canadian Society of Transplantation and Canadian Society of Nephrology Commentary on the 2017 KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

Purpose of review:

To review an international guideline on the evaluation and care of living kidney donors and provide a commentary on the applicability of the recommendations to the Canadian donor population.

Sources of information:

We reviewed the 2017 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors and compared this guideline to the Canadian 2014 Kidney Paired Donation (KPD) Protocol for Participating Donors.

Methods:

A working group was formed consisting of members from the Canadian Society of Transplantation and the Canadian Society of Nephrology. Members were selected to have representation from across Canada and in various subspecialties related to living kidney donation, including nephrology, surgery, transplantation, pediatrics, and ethics.

Key findings:

Many of the KDIGO Guideline recommendations align with the KPD Protocol recommendations. Canadian researchers have contributed to much of the evidence on donor evaluation and outcomes used to support the KDIGO Guideline recommendations.

Limitations:

Certain outcomes and risk assessment tools have yet to be validated in the Canadian donor population.

Implications:

Living kidney donors should be counseled on the risks of postdonation outcomes given recent evidence, understanding the limitations of the literature with respect to its generalizability to the Canadian donor population.

Outcomes of cinacalcet withdrawal in Australian dialysis patients

BACKGROUND

Secondary hyperparathyroidism (SHPT) in chronic kidney disease is associated with cardiovascular and bone pathology. Measures to achieve parathyroid hormone (PTH) target values and control biochemical abnormalities associated with SHPT require complex therapies, and severe SHPT often requires parathyroidectomy or the calcimimetic cinacalcet. In Australia, cinacalcet was publicly funded for dialysis patients from 2009 to 2015 when funding was withdrawn following publication of the EVOLVE study, which resulted in most patients on cinacalcet ceasing therapy. We examined the clinical and biochemical outcomes associated with this change at Australian renal centres.

AIM

To assess changes to biochemical and clinical outcomes in dialysis patients following cessation of cinacalcet.

METHODS

We conducted a retrospective study of dialysis patients who ceased cinacalcet after August 2015 in 11 Australian units. Clinical outcomes and changes in biochemical parameters were assessed over a 24- and 12-month period, respectively, from cessation of cinacalcet.

RESULTS

A total of 228 patients was included (17.7% of all dialysis patients from the units). Patients were aged 63 ± 15 years with 182 patients on haemodialysis and 46 on peritoneal dialysis. Over 24 months following cessation of cinacalcet, we observed 26 parathyroidectomies, 3 episodes of calciphylaxis, 8 fractures and 50 deaths. Eight patients recommenced cinacalcet, meeting criteria under a special access scheme. Biochemical changes from baseline to 12 months after cessation included increased levels of serum PTH from 54 (interquartile range 27-90) pmol/L to 85 (interquartile range 41-139) pmol/L (P < 0.0001), serum calcium from 2.3 ± 0.2 mmol/L to 2.5 ± 0.1 mmol/L (P < 0.0001) and alkaline phosphatase from 123 (92-176) IU/L to 143 (102-197) IU/L (P < 0.0001).

CONCLUSION

Significant increases in serum PTH, calcium and alkaline phosphatase occurred over a 12-month period following withdrawal of cinacalcet. Longer-term follow up will determine if these biochemical and therapeutic changes are associated with altered rates of parathyroidectomies and cardiovascular mortality and morbidity.

Association of prevalent vascular disease with allograft failure and mortality in live-donor kidney transplant recipients - a retrospective cohort study

Limited data exist regarding the impact of prevalent vascular disease after live-donor kidney transplantation. We aimed to determine the associations between the number of prevalent vascular diseases, allograft, and patient outcomes following live-donor transplantation. This cohort study used data from the Australia and New Zealand Dialysis and Transplant Registry. Rates between recipients of live-donor kidney transplants ± prevalent vascular disease prior to transplantation were calculated. The associations between vascular disease, allograft failure, and all-cause mortality were assessed using Cox regression modeling. Kaplan-Meier proportions were used to calculate all-cause mortality and death with a function graft stratified by vascular disease burden. Of 4742 live-donor recipients, 428 (9%) and 84 (2%) had prevalent vascular disease at 1 and ≥2 sites, respectively. Compared to recipients without vascular disease, the respective adjusted hazard ratios (95% confidence intervals) for patients with vascular disease at 1 and ≥2 sites were 1.78 (1.41-2.25) and 3.02 (2.03-4.50) for all-cause mortality; and 1.54 (1.26-1.88) and 2.28 (1.54-3.38) for allograft failure. All-cause mortality in recipients with vascular disease at 0, 1 and ≥2 sites was 0.028 (0.025, 0.031), 0.090 (0.073, 0.106) and 0.247 (0.196, 0.282) over the first 5-year post-transplant. There was an incremental association between the number of prevalent vascular disease sites and risk of allograft failure and all-cause mortality in live-donor kidney transplant recipients.

Randomised controlled trial of a video intervention and behaviour contract to improve medication adherence after renal transplantation: the VECTOR study protocol

INTRODUCTION

Non-adherence after kidney transplantation contributes to increased rejections, hospitalisations and healthcare expenditures. Although effective adherence interventions are sorely needed, increasing education and support to transplant recipients demands greater use of care providers' time and resources in a healthcare system that is stretched. The objective of this clinical trial is to determine the effectiveness of an electronically delivered video series and adherence behaviour contract on improving medication adherence to immunosuppressant medications.

METHODS AND ANALYSIS

A multicentre, parallel arm, randomised controlled trial will be conducted with four sites across North America (Saskatoon, Calgary, Halifax, Chicago). Adult patients will be randomised (1:1) to either the intervention (ie, home-based video education +behaviour contract plus usual care) or usual care alone. De novo transplant recipients will be enrolled prior to their hospital discharge and will be provided with electronic access to the video intervention (immediately) and adherence contract (1 month post-transplant). Follow-up electronic surveys will be provided at 3 and 12 months postenrolment. The primary outcome will be adherence at 12 months post-transplant, as measured by self-report Basel Assessment of Adherence to Immunosuppressive medications and immunosuppressant levels. Secondary outcomes include the difference in knowledge score between the intervention and control in groups (measured by the Kidney Transplant Understanding Tool); differences in self-efficacy (Generalised Self-efficacy Scale), Beliefs of Medicine Questionnaire (BMQ), quality of life (Short Form-12), patient satisfaction and cost utilisation. The study aims to recruit at least 200 participants across participating sites.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the University of Saskatchewan Behavioural Ethics Committee (Beh 18-63), and all patients provide informed consent prior to participating. This educational intervention aims to improve information retention and self-efficacy, leading to improved medication adherence after kidney transplantation, at low cost, with little impact to existing healthcare personnel. If proven beneficial, delivery can be easily implemented into standard of care.

TRIAL REGISTRATION NUMBER

NCT03540121; Pre-results.

Development of a patient-centered video series to improve education before kidney transplantation

BACKGROUND

Inadequate patient knowledge about transplantation can result in low patient satisfaction and contribute to poor clinical outcomes. The purpose of this patient-oriented research project was to develop an educational intervention for patients awaiting kidney transplantation.

METHODS

An educational intervention was developed by patients and health care providers, experts in medication adherence, video education, motivational psychology, and cultural education. Project objectives were defined and content was guided by a series of studies conducted with stakeholders. A review process was undertaken with additional patients, external health care providers and ninth grade high school students and edits were applied accordingly.

RESULTS

A set of six educational videos, ranging in length from 3 to 24 min, was created to describe the transplant process. The videos are patient friendly in design, and incorporate animations to explain complex information to accommodate low health literacy, and patient testimonials align the content with principles of adult learning theory. Feedback from external patient reviews [n = 8], external care providers [n = 13] and students [n = 26], indicate that the mini-series is informative and useful.

CONCLUSION

Patient involvement significantly influenced the development of a video series about kidney transplantation.

PRACTICE IMPLICATIONS

Patient engagement is integral for developing high quality and relevant educational interventions.

Development and Validation of the Kidney Transplant Understanding Tool (K-TUT)

BACKGROUND

Several educational interventions have been designed to improve patient knowledge before and after kidney transplantation. However, evaluation of such interventions has been difficult because validated instruments to measure knowledge-based outcomes in this population have not been developed.

OBJECTIVE

To create a tool to measure patient knowledge of kidney transplantation and to evaluate its validity.

METHODS

The Kidney Transplant Understanding Tool (K-TUT) was created using a stepwise iterative process. Experts in the field and transplant recipients were consulted to establish content validity. The K-TUT consists of 9 true/false and 13 multiple-choice questions, and scores are based on the number correct answers [YES/NO format] of 69 items. The questionnaire was piloted in a study that also measured health literacy (via the Short Test of Functional Health Literacy) in transplant candidates, whereas the main survey was mailed to transplant recipients. Test-retest was performed, and completed surveys were analyzed for internal consistency, construct validity, floor and ceiling effects, and reproducibility.

RESULTS

Surveys were offered to 106 pretransplant patients and 235 in the posttransplant period, and response rates were 38.7% (41/106) and 63.4% (149/235), respectively. The mean corrected scores were 53.1 ± 8.5 (77%) and 56.2 ± 6.3 (81%), respectively. Test-retest was performed over 20% of both cohorts and percent agreement ranged between 70% and 100% in the pretransplant group and 66% and 100% in the posttransplant group. Cronbach α ranged from 0.794 to 0.875 in all cohorts indicating favorable internal consistency. Increased health literacy in the pretransplant group was significantly associated with increased knowledge (r = 0.52; P < 0.001), suggestive of construct validity, and the absence of floor and ceiling effects was positive. The majority of transplant recipients (98/148, 67%) believed the questionnaire adequately assessed transplant knowledge, about a quarter (36/148, 24.3%) were "unsure," and 85% (126/148) agreed that no questions should be removed.

CONCLUSIONS

Although more study is warranted to further assess psychometric properties, the K-TUT appears to be a promising tool to measure transplant knowledge.

Education Before Kidney Transplantation

Context:

Poor knowledge about immunosuppressive (IS) medications remains a major problem for patients in the posttransplant setting. Therefore, more effective educational strategies in the pretransplant setting are being considered as a possible method to improve knowledge and readiness for the challenges of posttransplant care. However, the most effective/relevant content of a pretransplant educational program is yet to be determined.

Objective:

To identify pretransplant education topics from the posttransplant patient perspective.

Design:

A focus group meeting was conducted among 7 high-functioning, stable adult kidney transplant recipients recruited from the Saskatchewan Transplant Program. Demographic information including age, gender, occupation, background/ethnicity, and time since transplant were recorded. A moderator, assistant moderator, and research assistant facilitated the 90-minute focus group meeting using a predetermined semistructured interview guide. The session was audio recorded and transcribed verbatim. Nvivo software was used to code the data and identify emerging themes exploring views of participants relating to the educational information required for pretransplant patients.

Results:

Patients were satisfied with the education they had received. Ideas were classified into the following major themes—patient satisfaction, transplant waitlist, surgery, medications, posttransplant complications, lifestyle and monitoring, knowledge acquisition, illusion of control, and life changes posttransplant. Knowledge gaps were identified in all areas of the transplantation process and were not exclusive to IS medications.

Conclusion:

Misconceptions regarding transplantation were identified by a group of high-functioning, stable adult recipients who were satisfied with their clinical care. Future educational strategies should aim to address the entire transplantation process and not be limited to medications.

Contribution of impaired renal function to cardiovascular risk prediction models in renal transplant recipients

BACKGROUND

The Framingham risk score (FRS) and cardiovascular risk calculator for renal transplant recipients (CRCRTR-MACE) quantify cardiovascular risk in renal transplant recipients (RTR). In contrast to the FRS, the CRCRTR-MACE includes serum creatinine as a variable in the risk prediction equation.

OBJECTIVE

To determine the influence of impaired renal function on performances of the two equations.

METHODS

A chart review of 270 RTR transplanted from 1979 to 2012. High risk was defined at scores ≥20%. Standard statistical analyses included multivariate analysis (MVA), stepwise analysis, and odds ratio to estimate contributions of risk factors.

RESULTS

Mean transplant duration was 9.51 ± 6.65 yr. Mean eGFR was 59.19 ± 28.26 mL/min/1.73 m(2) . FRS and CRCRTR-MACE scores of least 20% were present in 9.3% and 24.8%, respectively, while 7.2% and 11.2% of RTR with eGFR ≥60 mL/min/1.73 m(2) were high risk, respectively. Mean age, blood pressure, TC:HDL ratio, smoking, and diabetes were evenly distributed in patients with varying eGFR. FRS scores remained similar at wide eGFR range (≤30 mL/min/1.73 m(2) -≥90 mL/min/1.73 m(2) ), while CRCRTR-MACE scores significantly increased as eGFR decreased.

CONCLUSIONS

CRCRTR-MACE identified more patients at high cardiovascular risk, even in those with more favorable renal function, suggesting a fundamental difference between the two calculators beyond renal function.

The Practical Implications of Using Estimated GFR as the Presumed Reference Variable to Estimate Transplant Chronic Kidney Disease

We determined the proportions of matched kidney transplant isotope GFRs (iGFRs) to the estimated functions (eGFRs) calculated from Isotope Dilution Mass Spectrometry (IDMS), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), and Cockcroft-Gault (CG) equations. One thousand four hundred and three iGFR/eGFR pairs on 390 kidney transplant patients were compared considering the iGFR or eGFR as the reference or test variable. Conformity of iGFR to CG estimates demonstrated the least bias of 1.3±18.4 mL/min/1.73 m2 (compared to 1.5±19.4 and - 2.2±19.2 for IDMS and CKDI-EPI, P<0.05) and CKD-EPI estimates the highest precision of 4.1±41.8 (compared to 11.3±43.9 for IDMS and 5.7±37.3 for CG; P<0.05). IDMS eGFR cut off less than 60 and less than 30 mL/min/1.73m2 were correctly matched by iGFR in 79.4% and 49.1% of the times, while CKD-EPI was matched by iGFR in 83.5% and 52.5%. CG was matched in 78.3% and 53.6%. IGFR cut off levels of less than 60, and less than 30 mL/min/1.73m2 were predicted by IDMS in 83.8% and 64.0% of the times. CKD-EPI was correct in 77.8% and 59.0% and CG in 82.5% and 41.6%, respectively. Transplant eGFR results obtained by CKD-EPI or CG are likely to be more precise and less biased than IDMS.

Severe antibody-mediated rejection following IVIG infusion in a kidney transplant recipient with BK-virus nephropathy

Intravenous immune-globulin (IVIG) use in renal transplantation has increased, with common uses including desensitization, treatment of antibody mediated rejection and adjunctive therapy for BK virus nephropathy. Although considered generally safe, potential side effects can occur in up to 23% of patients including acute kidney injury. We present a case of an unexpected cause of acute kidney injury in a renal transplant recipient following IVIG infusion. A 48-year-old nonsensitized female with end stage renal disease secondary to polycystic kidney disease received a deceased donor kidney transplant. The initial post-transplant period was unremarkable however at three years post-transplant the patient develops BK virus nephropathy. Despite a reduction in immunosuppression, graft function worsened and IVIG infusion was commenced. Immediately following the IVIG infusion, the patient develops anuric acute kidney injury necessitating hemodialysis. Renal transplant biopsy performed before and after the IVIG infusion revealed the de novo development of acute antibody mediated rejection and donor specific antibodies in the serum. Anti-HLA and donor-specific antibodies were also confirmed in a diluted sample of the IVIG preparation. We argue that the anti-HLA antibodies present in the IVIG caused an acute antibody mediated rejection in this previously nonsensitized female.

Effect of N-acetylcysteine on serum creatinine and kidney function: results of a randomized controlled trial

BACKGROUND

Evidence for a protective effect of N-acetylcysteine (NAC) on acute and chronic kidney disease is equivocal, and controversy persists about whether NAC affects creatinine level independently of actual kidney function. Study objectives are to investigate whether NAC affects serum creatinine level independently of alterations in other measures of kidney function.

STUDY DESIGN

Double-blind randomized controlled trial.

SETTING & PARTICIPANTS

Patients with stage 3 chronic kidney disease (n = 60), Canada, 2007-2008.

INTERVENTION

Participants were randomly allocated to receive 4 doses of oral NAC (each 1,200 mg) or placebo, administered at 12-hour intervals.

OUTCOME

The primary outcome was change in serum creatinine level between baseline and 4 hours after the last treatment dose. In addition, changes in other parameters of kidney function were measured between baseline and 4, 24, or 48 hours after the last treatment dose.

MEASUREMENTS

Serum creatinine, cystatin C, 24-hour urine protein and creatinine excretion, and creatinine clearance.

RESULTS

60 patients, mean age of 70 years, 75% men, 50% had diabetes, with mean creatinine clearance of 43.7 ± 18.8 (SD) mL/min were enrolled. Between baseline and 4 hours posttreatment, serum creatinine level decreased by 0.044 ± 0.15 mg/dL in the NAC group and 0.040 ± 0.18 mg/dL in the placebo group (95% CI for difference, -0.09 to 0.08; P = 0.9). No significant differences between groups were observed for change in serum creatinine, cystatin C, urine protein, urine creatinine, or creatinine clearance values at any time.

LIMITATIONS

Blinding patients to orally administered liquid NAC is difficult and it is possible that patients receiving NAC were not sufficiently blinded. Effects of NAC beyond 48 hours of treatment were not evaluated.

CONCLUSIONS

In this randomized controlled trial, NAC had no short-term effect on creatinine level and did not decrease urine protein excretion within 48 hours of treatment.

Individualized therapy to prevent bone mineral density loss after kidney and kidney-pancreas transplantation

BACKGROUND AND OBJECTIVES

Most patients who undergo kidney or kidney-pancreas transplantation have renal osteodystrophy, and immediately after transplantation bone mineral density (BMD) commonly falls. Together, these abnormalities predispose to an increased fracture incidence. Bisphosphonate or calcitriol therapy can preserve BMD after transplantation, but although bisphosphonates may be more effective, they pose potential risks for adynamic bone.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A total of 153 kidney (61%) and kidney-pancreas (39%) transplant recipients were allocated to bisphosphonate (62%) or calcitriol (38%) therapy using an algorithm that incorporated BMD, prevalent vertebral fracture, biomarkers of bone turnover, and risk factor assessment. Patients received cholecalciferol and calcium as appropriate and were followed for 12 mo.

RESULTS

Patients who were treated with bisphosphonates had lower BMD at the lumbar spine and femoral neck and longer time on dialysis. Age and gender were similar between the groups. At 12 mo, bisphosphonate-treated patients had significant BMD increases at the lumber spine and femoral neck and a negative trend at the wrist. Patients who were allocated to calcitriol, who were assessed to have lower baseline fracture risk, had no significant change in BMD at any site. At 1 yr, mean levels of bone turnover marker and intact parathyroid hormone normalized in both groups. Incident fracture rates did not differ significantly.

CONCLUSIONS

With targeted treatment, BMD levels were stable or improved and bone turnover markers normalized. This algorithm provides a guide to targeting therapy after transplantation that avoids BMD loss and may reduce suppression of bone turnover.

Mesna for treatment of hyperhomocysteinemia in hemodialysis patients: a placebo-controlled, double-blind, randomized trial

BACKGROUND AND OBJECTIVES

Increased plasma total homocysteine is a graded, independent risk factor for the development of atherosclerosis and thrombosis. More than 90% of patients with end-stage renal disease have hyperhomocysteinemia despite vitamin supplementation. It was shown in previous studies that a single intravenous dose of mesna 5 mg/kg caused a drop in plasma total homocysteine that was significantly lower than predialysis levels 2 d after dosing. It was hypothesized 5 mg/kg intravenous mesna administered thrice weekly, before dialysis, for 8 wk would cause a significant decrease in plasma total homocysteine compared with placebo.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Patients with end-stage renal disease were randomly assigned to receive either intravenous mesna 5 mg/kg or placebo thrice weekly before dialysis. Predialysis plasma total homocysteine concentrations at weeks 4 and 8 were compared between groups by paired t test.

RESULTS

Mean total homocysteine at 8 wk in the placebo group was 24.9 micromol/L compared with 24.3 micromol/L in the mesna group (n = 22 [11 pairs]; mean difference 0.63). Interim analysis at 4 wk also showed no significant difference between mesna and placebo (n = 32 [16 pairs]; placebo 26.3 micromol/L, mesna 24.5 micromol/L; mean difference 1.88). Multivariable adjustments for baseline characteristics did not alter the analysis. Plasma mesna seemed to reach steady-state concentrations by 4 wk.

CONCLUSIONS

It is concluded that 5 mg/kg mesna does not lower plasma total homocysteine in hemodialysis patients and that larger dosages may be required.

Effect of N-acetylcysteine on renal function in patients with chronic kidney disease

BACKGROUND

N-acetylcysteine (NAC) is commonly administered to high-risk individuals to attenuate the risk of contrast-induced nephropathy in spite of the debate regarding its efficacy. In several studies serum creatinine decreased after exposure to NAC and contrast dye. The mechanism by which NAC attenuates the decline in renal function is not known. Studies in subjects with normal renal function suggest NAC may have an effect on tubular secretion.

AIM

The aim of this study was to determine the effect of NAC on renal function, measured by serum creatinine and Cystatin C, in patients with stage 3 chronic kidney disease.

METHOD

Serum creatinine and Cystatin C were measured prior to, 4, 24 and 48 h after the administration of 600 mg oral NAC in 30 patients. The protocol was repeated with the addition of 1200 mg oral cimetidine administered 3 h before NAC.

RESULTS

Serum creatinine was not significantly different from baseline (186 +/- 65 micromol/L) to 4 h (185 +/- 62 micromol/L), 24 h (187 +/- 64 micromol/L) or 48 h (184 +/- 61 micromol/L) post NAC, nor were Cystatin C levels. Co-administration of cimetidine resulted in a significant rise in serum creatinine with no change in Cystatin C levels.

CONCLUSION

This study failed to detect a change in serum creatinine or Cystatin C after a single dose of NAC in participants with stage 3 chronic kidney disease. Further randomized trials of multiple doses and longer follow up are needed to confirm these results.

Daily Hemodialysis: A Systematic Review

Several studies have reported improved outcomes with daily hemodialysis (DHD), but the strength of this evidence has not been evaluated. The published evidence on DHD was synthesized and its quality rated to inform need and sample size calculations for a randomized trial. Citations were identified in MEDLINE and EMBASE using validated search strategies. Dialysis journals that were not indexed and bibliographies of relevant articles were hand-searched. Two authors reviewed all citations. Articles that reported original data on five or more adults who were receiving DHD (1.5 to 3 h, 5 to 7 d/wk) for > or = 3 mo were included. Twenty-five articles reporting 14 unique populations with 268 patients (five to 72 per study) met inclusion criteria. Of the 14 cohorts, 13 were studied with an observational design, 10 were studied prospectively, and four had parallel control groups. Mean age ranged form 41 to 64 yr, mean time on dialysis was 2 to 11 yr, 0 to 28% of patients had diabetes, > 90% had arteriovenous fistulae, and > 50% were dialyzed at home. Most data were described at < or = 12 mo of follow-up. Outcomes included quality of life, cardiovascular disease, erythropoiesis, nutritional status, hospitalizations, and vascular access failures. Reporting was too heterogeneous to allow pooling of data. Ten of 11 studies suggested improvements in blood pressure; findings for other outcomes varied. Discontinuation of DHD occurred in 0 to 57% in-center and 0 to 15% home patients. Studies of DHD are limited by small sample size, nonideal control groups, selection and dropout biases, and paucity of data on potential risks. Randomized trials with adequate statistical power are required to establish the efficacy and the safety of DHD.

Prevention of recurrent cerebral ischemic events in patients with patent foramen ovale and cryptogenic strokes or transient ischemic attacks

BACKGROUND

Patent foramen ovale (PFO) is found in up to 50% of patients less than 55 years of age who have had a stroke. Therapeutic options include no therapy, antiplatelet therapy, warfarin and surgical closure of the PFO.

OBJECTIVES

To determine the relative and attributable risks of PFO for recurrent cerebral ischemic events in young patients with stroke or transient ischemic attacks. The predictors of recurrent cerebral ischemic events and the effects of different therapies on recurrence rates were sought.

DESIGN

Follow-up of a retrospective cohort of patients with cryptogenic stroke or transient ischemic attacks identified from an echocardiography database.

SETTING

University-based regional neurology referral centre.

PATIENTS

Consecutive group of 90 patients less than 60 years of age who underwent transesophageal echocardiography following a cryptogenic transient ischemic attack (TIA) or stroke (cerebrovascular accident [CVA]) between 1991 and 1997.

INTERVENTIONS

Structured telephone interviews and chart reviews.

RESULTS

Fifty-two patients had a PFO, and 38 patients did not have a PFO. During a mean follow-up of 46 months, 19 recurrent cerebral ischemic events (12 TIA and seven CVA) occurred in 14 patients with PFO, and eight recurrent events (three TIA and five CVA) occurred in six patients without PFO. The recurrence rates were 12% and 5%/patient/year in the PFO and control groups, respectively, for a crude recurrence rate ratio of 2.39 (95% CI 1.01 to 6.32, P < 0.03). The attributable risk of PFO in recurrent neurological events was 7%/patient/year. In a Cox regression model, predictors of recurrent neurological events were presence of PFO (hazard ratio 5.27, 95% CI 1.58 to 17.6, P < 0.007), history of migraine (hazard ratio 4.54, 95% CI 1.11 to 18.52, P < 0.035), hypertension requiring therapy (hazard ratio 3.5, 95% CI 1.33 to 9.01, P < 0.01), and antiplatelet or no therapy instead of warfarin therapy (hazard ratio 2.88, 95% CI 1.11 to 8.7, P < 0.04). Fourteen patients underwent surgical closure of PFO; there were no neurological recurrences during a mean follow-up of 43 months (crude incidence rate difference 12%/patient/year, 95% CI 6.6 to 17.9, P < 0.02).

CONCLUSIONS

Patients with PFO had a significantly higher rate of recurrent cerebral ischemic events than those without PFO. Surgical PFO closure prevented any recurrences during a mean follow-up of 43 months. Warfarin was better than antiplatelet therapy or no therapy in preventing recurrences.

Expressed alpha 1-adrenoceptors in adult rat brown adipocytes are primarily of alpha 1A subtype

The main objective of this study was to characterize the alpha 1-adrenoceptors expressed in adult rat brown adipocytes. For this purpose, membrane fractions were prepared from brown adipose tissue as well as from isolated brown adipocytes. The following are major findings: (i) BAT membranes were considerably enriched in alpha 1-adrenoceptors (specific [3H]prazosin binding, Bmax, 79.49 +/- 16.77 fmol/mg protein; KD, 0.24 +/- 0.04 nM); (ii) among the cells that comprise brown adipose tissue, brown adipocytes were enriched in alpha 1-adrenoceptors; (iii) > 95% of total alpha 1-adrenoceptors were resistant to inactivation by 20 microM chloroethylclonidine, which readily and essentially completely inactivated alpha 1B-adrenoceptors in rat liver membranes; (iv) brown adipose tissue membrane alpha 1-adrenoceptors showed high affinity towards 5-methyl urapidil (KD 7.23 +/- 2.49 nM) and WB 4101 (KD 0.66 +/- 0.30 nM) and low affinity towards BMY 7378 (KD 0.34 +/- 0.03 microM); essentially similar affinities for these drugs were seen for membranes prepared from brown adipocytes; and (v) EBDA/LIGAND analysis of 5-methyl urapidil, WB 4101, and BMY 7378 competition curves revealed the presence of a single binding site for these drugs. Recent work has documented that 5-methyl urapidil and WB 4101 interact with high affinity with alpha 1A-adrenoceptors, while BMY 7378 interacts with high affinity with alpha 1D-adrenoceptors. Taken together, these findings are consistent with the view that alpha 1-adrenoceptors expressed in adult rat BAT are mainly of the alpha 1A subtype.