The Second International Consensus Guidelines on the Management of BK Polyomavirus in Kidney Transplantation.

BK polyomavirus (BKPyV) remains a significant challenge after kidney transplantation. International experts reviewed current evidence and updated recommendations according to Grading of Recommendations, Assessment, Development, and Evaluations (GRADE). Risk factors for BKPyV-DNAemia and biopsy-proven BKPyV-nephropathy include recipient older age, male sex, donor BKPyV-viruria, BKPyV-seropositive donor/-seronegative recipient, tacrolimus, acute rejection, and higher steroid exposure. To facilitate early intervention with limited allograft damage, all kidney transplant recipients should be screened monthly for plasma BKPyV-DNAemia loads until month 9, then every 3 mo until 2 y posttransplant (3 y for children). In resource-limited settings, urine cytology screening at similar time points can exclude BKPyV-nephropathy, and testing for plasma BKPyV-DNAemia when decoy cells are detectable. For patients with BKPyV-DNAemia loads persisting >1000 copies/mL, or exceeding 10 000 copies/mL (or equivalent), or with biopsy-proven BKPyV-nephropathy, immunosuppression should be reduced according to predefined steps targeting antiproliferative drugs, calcineurin inhibitors, or both. In adults without graft dysfunction, kidney allograft biopsy is not required unless the immunological risk is high. For children with persisting BKPyV-DNAemia, allograft biopsy may be considered even without graft dysfunction. Allograft biopsies should be interpreted in the context of all clinical and laboratory findings, including plasma BKPyV-DNAemia. Immunohistochemistry is preferred for diagnosing biopsy-proven BKPyV-nephropathy. Routine screening using the proposed strategies is cost-effective, improves clinical outcomes and quality of life. Kidney retransplantation subsequent to BKPyV-nephropathy is feasible in otherwise eligible recipients if BKPyV-DNAemia is undetectable; routine graft nephrectomy is not recommended. Current studies do not support the usage of leflunomide, cidofovir, quinolones, or IVIGs. Patients considered for experimental treatments (antivirals, vaccines, neutralizing antibodies, and adoptive T cells) should be enrolled in clinical trials.

The Impact of Combined Warm and Cold Ischemia Time on Post-transplant Outcomes.

Background: Prolonged warm ischemia time (WIT) and cold ischemia time (CIT) are independently associated with post-transplant graft failure; their combined impact has not been previously studied. We explored the effect of combined WIT/CIT on all-cause graft failure following kidney transplantation. Methods: The Scientific Registry of Transplant Recipients was used to identify kidney transplant recipients from January 2000 to March 2015 (after which WIT was no longer separately reported), and patients were followed until September 2017. A combined WIT/CIT variable (excluding extreme values) was separately derived for live and deceased donor recipients using cubic splines; for live donor recipients, the reference group was WIT 10 to <23 minutes and CIT >0 to <0.42 hours, and for deceased donor recipients the WIT was 10 to <25 minutes and CIT 1 to <7.75 hours. The adjusted association between combined WIT/CIT and all-cause graft failure (including death) was analyzed using Cox regression. Secondary outcomes included delayed graft function (DGF). Results: A total of 137 125 recipients were included. For live donor recipients, patients with prolonged WIT/CIT (60 to ≤120 minutes/3.04 to ≤24 hours) had the highest adjusted hazard ratio (HR) for graft failure (HR = 1.61, 95% confidence interval [CI] = 1.14-2.29 relative to the reference group). For deceased donor recipients, a WIT/CIT of 63 to ≤120 minutes/28 to ≤48 hours was associated with an adjusted HR of 1.35 (95% CI = 1.16-1.58). Prolonged WIT/CIT was also associated with DGF for both groups although the impact was more driven by CIT. Conclusions: Combined WIT/CIT is associated with graft loss following transplantation. Acknowledging that these are separate variables with different determinants, we emphasize the importance of capturing WIT and CIT independently. Furthermore, efforts to reduce WIT and CIT should be prioritized.

Contexte: La période prolongée d'ischémie à chaud (WIT­warm ischemia time) et la période prolongée d'ischémie à froid (CIT­cold ischemia time) ont été associées de façon indépendante à une défaillance du greffon post-transplantation, mais leur effet combiné n'a jamais été étudié. Nous avons examiné l'effet combiné WIT/CIT sur la défaillance du greffon toutes causes confondues après une transplantation rénale. Méthodologie: Le Scientific Registry of Transplant Recipients a été utilisé pour identifier les receveurs d'une greffe de rein entre janvier 2000 et mars 2015 (date après laquelle la WIT n'a plus été rapportée séparément). Les patients ont été suivis jusqu'en septembre 2017. Une variable combinée WIT/CIT (excluant les valeurs extrêmes) a été dérivée de façon isolée pour les donneurs vivants et les donneurs décédés à l'aide d'une fonction spline cubique. La WIT du groupe référence pour les donneurs vivants se situait entre 10 et <23 minutes, et la CIT entre 0 et <0,42 heure; pour les donneurs décédés, la WIT se situait entre 10 et <25 minutes, et la CIT entre 1 et <7,75 heures. L'association corrigée entre une combinaison WIT/CIT et la défaillance du greffon toutes causes confondues (y compris le décès) a été analysée à l'aide de la régression de Cox. Les résultats secondaires incluaient une reprise retardée de la fonction du greffon (RRFG). Résultats: Un total de 137 125 receveurs d'un rein a été inclus. Dans le groupe des receveurs d'un organe provenant d'un donneur vivant, les patients avec une WIT/CIT prolongée (60 à ≤120 minutes/3,04 à ≤24 heures) présentaient un risque relatif corrigé plus élevé de défaillance du greffon (RRc: 1,61; IC 95 %: 1,14-2,29) par rapport au groupe de référence. Dans le groupe des receveurs d'un organe provenant d'un donneur décédé, une combinaison WIT/CIT de 63 à ≤120 minutes/28 à ≤48 heures a été associée à un RRc de 1,35 (IC 95 %: 1,16-1,58). La WIT/CIT prolongée a également été associée à une RRFG pour les deux groupes, bien que cet effet ait été davantage influencé par la CIT. Conclusion: La combinaison WIT/CIT est associée à la perte du greffon après la transplantation. Sachant qu'il s'agit de variables distinctes avec des déterminants différents, nous soulignons l'importance de rapporter la WIT et la CIT de façon indépendante. Qui plus est, les efforts visant à réduire la WIT et la CIT devraient être prioritaires.

Challenges in the management of the kidney allograft: from decline to failure: conclusions from a Kidney Disease: Improving Global Outcomes (KDIGO) Controversies Conference.

In March 2022, Kidney Disease: Improving Global Outcomes (KDIGO) held a virtual Controversies Conference to address the important but rarely examined phase during which the kidney transplant is failing or has failed. In addition to discussing the definition of a failing allograft, 4 broad areas were considered in the context of a declining functioning graft: prognosis and kidney failure trajectory; immunosuppression strategies; management of medical and psychological complications, and patient factors; and choice of kidney replacement therapy or supportive care following graft loss. Identifying and paying special attention to individuals with failing allografts was felt to be important in order to prepare patients psychologically, manage immunosuppression, address complications, prepare for dialysis and/or retransplantation, and transition to supportive care. Accurate prognostication tools, although not yet widely available, were embraced as necessary to define allograft survival trajectories and the likelihood of allograft failure. The decision of whether to withdraw or continue immunosuppression after allograft failure was deemed to be based most appropriately on risk-benefit analysis and likelihood of retransplantation within a few months. Psychological preparation and support was identified as a critical factor in patient adjustment to graft failure, as was early communication. Several models of care were noted that enabled a medically supportive transition back to dialysis or retransplantation. Emphasis was placed on the importance of dialysis-access readiness before initiation of dialysis, in order to avoid use of central venous catheters. The centrality of the patient to all management decisions and discussions was deemed to be paramount. Patient "activation," which can be defined as engaged agency, was seen as the most effective way to achieve success. Unresolved controversies, gaps in knowledge, and areas for research were also stressed in the conference deliberations.

The Association of Pre-Transplant C-Peptide Level with the Development of Post-Transplant Diabetes: A Cohort Study.

Background: Post-transplant diabetes mellitus (PTDM) is an important complication after kidney transplantation that results in reduced patient and allograft survival. Although there are established risk factors for PTDM, whether pretransplant C-peptide levels associate with PTDM is unknown. Therefore, in this study, we aimed to examine the association of pretransplant C-peptide levels with PTDM. Methods: This was a cohort study of nondiabetic adult patients who underwent kidney transplant in Nova Scotia, Canada, between January 1, 2016, and March 31, 2021, with fasting C-peptide levels measured before transplant. Multivariable logistic regression was used to determine the association of pretransplant C-peptide (dichotomized around the median) with PTDM at 1 year post transplant. Given the known association between pretransplant obesity and PTDM, we repeated our primary analysis in a cohort restricted to a BMI of 20-35 kg/m2. Results: The median C-peptide value was 3251 (Q1 2480, Q3 4724); pretransplant C-peptide level was dichotomized at 3000 pmol/L. PTDM occurred in 25 (19%) individuals. Thirty percent of patients in the high and only 2% of patients in the low C-peptide groups developed PTDM (P<0.001). A C-peptide level ≥3000 pmol/L was strongly associated with PTDM in multivariable analysis (OR=18.9, 95% CI, 2.06 to 174.2). In a restricted cohort with a BMI of 20-35 kg/m2, an elevated pretransplant C-peptide remained independently associated with the risk of PTDM (OR=15.7, 95% CI, 1.64 to 150.3). C-peptide was the only factor independently associated with PTDM in this restricted BMI cohort. Conclusions: A pretransplant C-peptide level ≥3000 pmol/L was associated with a nearly 20-fold increased odds of PTDM at 1 year post kidney transplantation. Identifying patients with high pretransplant C-peptide levels may therefore help identify those at risk for PTDM who may benefit from focused preventative and therapeutic interventions and support.

The windows of opportunity.

Models to predict survival after kidney transplantation have been developed, which have assisted clinicians in the selection of patients suitable for kidney transplant wait-listing. However, these models have ignored the competing problem of delisting and wait-list mortality, which are equally important in the decision-making process for determining transplant suitability. This commentary focuses on a newly introduced concept that integrates and quantifies the probability of wait-list survival versus receiving a deceased donor kidney transplant.

Comparing the Net Benefits of Adult Deceased Donor Kidney Transplantation for a Patient on the Preemptive Waiting List vs a Patient Receiving Dialysis.

Importance: Preemptive kidney transplantation is the preferred treatment for end-stage kidney disease. However, deceased donor (DD) kidneys are limited, and the net benefit of allocating kidneys to a preemptively waitlisted patient rather than to a patient receiving dialysis is unclear. Objective: To estimate the net benefit and costs of allocating kidneys to preemptively waitlisted patients vs those receiving dialysis. Design, Setting, and Participants: This medical decision analytical model used data from the 2020 US Renal Data System to calculate patient survival among waitlisted patients who received a DD kidney transplant. Four patients were simulated, with similar characteristics: (1) a patient on the preemptive waiting list receiving a DD transplant, (2) a patient on the preemptive waiting list never receiving a transplant, (3) a waitlisted patient already receiving dialysis (dialysis vintage <1 year) receiving a transplant, and (4) a waitlisted patient already receiving dialysis (dialysis vintage <1 year) never receiving a transplant. Annual probability of initiating dialysis (for patients 1 and 2) and duration of dialysis (for patients 3 and 4) were varied in sensitivity analyses. Exposures: Allocating a DD kidney to a patient on the preemptive waiting list vs the same kidney to a patient receiving dialysis for less than 1 year, with similar recipient characteristics. Main Outcomes and Measures: Differences in projected quality-adjusted life-years (QALYs) and total costs. Results: In a simulated patient with a mean start age of 50 years (range, 30-64 years), the patient receiving a preemptive DD transplantation experienced 10.58 (95% CI, 10.36-10.80) QALYs, and the patient on the preemptive waiting list never transplanted experienced 6.83 (95% CI, 6.67-6.99) QALYs. The patient receiving DD transplantation after less than 1 year of dialysis experienced 10.33 (95% CI, 10.21-10.55) QALYs, and the patient receiving dialysis who remained on the waiting list experienced 6.20 (95% CI, 6.04-6.36) QALYs; allocating a DD kidney to the preemptive patient added 3.75 (95% CI, 3.57-3.93) QALYs, whereas allocating the kidney to the patient already receiving dialysis added 4.13 (95% CI, 3.92-4.31) QALYs. While the estimated posttransplant survival was longest for the preemptive transplant recipient, preferentially allocating the kidney to the preemptive patient results in 0.39 (95% CI, 0.49-0.29) fewer QALYs. The net cost of preemptive transplantation was $54 100 (95% CI, $44 100-$64 100) more than transplantation to a waitlisted patient. If the rate of transitioning to dialysis was 20 (rather than 33) events per 100 patient waiting list-years, the net QALYs were -0.67 (95% CI, -0.78 to -0.56). If the patient was receiving dialysis for 3 to 4 years (vs <1 year) the net benefit was not significantly different; however, net costs were considerably higher for the preemptive option. Conclusions and Relevance: In this decision analytic model study, although allocating DD kidneys to patients preemptively was the best option from a patient perspective, allocating DD kidneys to patients receiving dialysis was a better use of a scare resource from a societal perspective.

Economic Evaluation of Screening for Polyomavirus Infection in Kidney Transplant Recipients: A Cost-Utility Analysis.

Screening for polyomavirus infection after kidney transplantation is recommended by clinical practice guidelines, but cost-effectiveness of this strategy is uncertain. The aim of this study was to estimate the incremental costs and benefits of routine screening for polyomavirus infection compared with no screening in kidney transplant recipients. Methods: Probabilistic Markov models were constructed to compare the health and economic benefits of routine screening for polyomavirus infection using real-time polymerase chain reaction assay. A series of 1-way and probabilistic sensitivity analyses were conducted to define the most influential variables in the model. Results: Monthly screening for 6 mo followed by 3 monthly screenings until 12 mo after transplant was dominant (lower costs and improved outcomes). Compared with no screening, the incremental benefits of screening were 0.294 life-years saved and 0.232 quality-adjusted life-years saved. Total savings from screening were $6986 Australian dollars ($5057 US dollars). The cost-effectiveness ratios were most sensitive to the costs of transplantation and dialysis, age of transplantation, prevalence of viremia, and probability of death in patients with a history of polyomavirus-associated nephropathy. Probabilistic sensitivity analysis indicated that screening (compared with no screening) was the dominant strategy across all plausible ranges of transition probabilities. Conclusions: Screening for polyomavirus infections 1 year following transplantation appears to save money, improves survival, and improves quality of life in kidney transplant recipients.

Disparities in Access to Preemptive Repeat Kidney Transplant: Still Missing the Mark?

Background: The need for repeat transplant due to failing kidney allografts is increasing over time. The benefit of preemptive kidney retransplant (PKre-T) is controversial. Marginalized populations are less likely to undergo their first transplant preemptively; however, whether inequities exist for those undergoing PKre-T is unknown. Methods: We performed a cohort study of adult patients undergoing live and deceased kidney transplant in the United States from 2000 to 2018 identified using the Scientific Registry of Transplant Recipients, and we identified patients with first preemptive kidney transplant (PKT) and PKre-T. In the primary analysis, a multivariable logistic regression was used to identify independent predictors of PKre-T. In secondary analyses, multivariable Cox models were used to determine the association of PKre-T with death-censored and all-cause graft loss. Results: In total, 4910 (15.5%) patients underwent PKre-T, and 43,293 (19.1%) underwent first PKT. Inequities in access to PKre-T persisted (OR, 0.49; 95% CI, 0.44 to 0.55 for unemployed versus full time; OR, 1.61; 95% CI, 1.14 to 2.25 for graduate school versus not completing high school; OR, 0.61; 95% CI, 0.52 to 0.70 for Black versus White race); 7.1% of all transplanted Black patients received PKre-T versus 17.4% of White patients. Women were more likely to undergo PKre-T than men (OR, 1.42; 95% CI, 1.29 to 1.57). PKre-T was associated with superior graft survival relative to retransplant after a period of dialysis (HR, 0.73; 95% CI, 0.67 to 0.80 for all-cause graft failure; HR, 0.72; 95% CI, 0.65 to 0.81 for death-censored graft loss). Conclusions: Despite improved patient and graft survival, inequities in access to PKre-T persist. Patients with lower education, patients with reduced employment status, patients of Black race, and men are less likely to receive PKre-T.

Optimal Sequencing of Deceased Donor and Live Donor Kidney Transplant Among Pediatric Patients With Kidney Failure.

Importance: In the US, live donor (LD) kidney transplant rates have decreased in pediatric recipients. Pediatric patients with kidney failure will likely need more than 1 kidney transplant during their lifetime, but the optimal sequence of transplant (ie, deceased donor [DD] followed by LD or vice versa) is not known. Objective: To determine whether pediatric recipients should first receive a DD allograft followed by an LD allograft (DD-LD sequence) or an LD allograft followed by a DD allograft (LD-DD sequence). Design, Setting, and Participants: This decision analytical model examined US pediatric patients with kidney failure included in the US Renal Data System 2019 Report who were waiting for a kidney transplant, received a transplant, or experienced graft failure. Interventions: Kidney transplant sequences of LD-DD vs DD-LD. Main Outcomes and Measures: Difference in projected life-years between the 2 sequence options. Results: Among patients included in the analysis, the LD-DD sequence provided more net life-years in those 5 years of age (1.82 [95% CI, 0.87-2.77]) and 20 years of age (2.23 [95% CI, 1.31-3.15]) compared with the DD-LD sequence. The net outcomes in patients 10 years of age (0.36 [95% CI, -0.51 to 1.23] additional life-years) and 15 years of age (0.64 [95% CI, -0.15 to 1.39] additional life-years) were not significantly different. However, for those aged 10 years, an LD-DD sequence was favored if eligibility for a second transplant was low (2.09 [95% CI, 1.20-2.98] additional life-years) or if the LD was no longer available (2.32 [95% CI, 1.52-3.12] additional life-years). For those aged 15 years, the LD-DD sequence was favored if the eligibility for a second transplant was low (1.84 [95% CI, 0.96-2.72] additional life-years) or if the LD was no longer available (2.49 [95% CI, 1.77-3.27] additional life-years). Access to multiple DD transplants did not compensate for missing the LD opportunity. Conclusions and Relevance: These findings suggest that the decreased use of LD kidney transplants in pediatric recipients during the past 2 decades should be scrutinized. Given the uncertainty of future recipient eligibility for retransplant and future availability of an LD transplant, the LD-DD sequence is likely the better option. This strategy of an LD transplant first would not only benefit pediatric recipients but allow DD kidneys to be used by others who do not have an LD option.

The Role of Donor Sex in Females Undergoing Repeat Kidney Transplant: Does Prior Donor Sex Matter?

Female recipients of male donor kidneys are at increased risk for graft failure because of the HY antigen effect. However, whether prior transplant with a male donor impacts subsequent transplant outcomes is unknown. Therefore, the purpose of this study was to determine whether prior male-current male donor sex is associated with an increased risk of graft failure in female recipients. Methods: We performed a cohort study of adult female recipients undergoing a second kidney transplant (2000-2017), identified using the Scientific Registry of Transplant Recipients. Using multivariable Cox models, we analyzed the risk of death-censored graft loss (DCGL) if the second transplant was from a male versus female kidney donor, conditional on donor sex at the time of the first transplant. In a secondary analysis, we stratified results by recipient age (>50 or ≤50 y) at the time of retransplant. Results: Of 5594 repeat kidney transplants, 1397 (25.0%) developed DCGL. Overall, there was no association between first and second donor sex pairing and DCGL. A prior and current female donor (FD1FD2) posed a higher risk for DCGL in recipients aged >50 y at second transplant (hazard ratio,≤0.67, confidence interval 0.46-0.98, for all other donor combinations), but posed a lower risk if aged ≤50 y at retransplant (hazard ratio, ≥1.37, confidence interval 1.04-1.80, for all other donor combinations). Conclusions: Overall, past-current donor sex pairing was not associated with DCGL in female recipients undergoing second kidney transplant; however, the risk with a past and current female donor was increased in older, and decreased in younger, female recipients at retransplant.

Predictors and Complications of Post Kidney Transplant Leukopenia.

BACKGROUND: Leukopenia occurs frequently following kidney transplantation and is associated with adverse clinical outcomes including increased infectious risk. In this study we sought to characterize the causes and complications of leukopenia following kidney transplantation. METHODS: In a cohort of adult patients (≥18 years) who underwent kidney transplant from Jan 2006-Dec 2017, we used univariable Cox proportional Hazards models to identify predictors of post-transplant leukopenia (WBC < 3500 mm3). Factors associated with post-transplant leukopenia were then included in a multivariable backwards stepwise selection process to create a prediction model for the outcome of interest. Cox regression analyses were subsequently used to determine if post-transplant leukopenia was associated with complications. RESULTS: Of 388 recipients, 152 (39%) developed posttransplant leukopenia. Factors associated with leukopenia included antithymocyte globulin as induction therapy (HR 3.32, 95% CI 2.25-4.91), valganciclovir (HR 1.84, 95% CI 1.25-2.70), tacrolimus (HR 3.05, 95% CI 1.08-8.55), prior blood transfusion (HR 1.17 per unit, 95% CI 1.09- 1.25), and donor age (HR 1.02 per year, 95% CI 1.00-1.03). Cytomegalovirus infection occurred in 26 patients with leukopenia (17.1%). Other than cytomegalovirus, leukopenia was not associated with posttransplant complications. CONCLUSION: Leukopenia commonly occurred posttransplant and was associated with modifiable and non-modifiable pretransplant factors.

In Search of a Better Outcome: Opting Into the Live Donor Paired Kidney Exchange Program.

BACKGROUND: Live donor (LD) kidney transplantation is the best option for patients with end-stage kidney disease (ESKD). However, this may not be the best option if a patient's donor is older and considerably smaller in weight. Patient (A) with a less than ideal donor (Donor A) might enter into a live donor paired exchange (LDPE) program with the hopes of swapping for a better-quality organ. A second patient (B) who is in the LDPE may or may not benefit from this exchange with Donor A. METHODS: This medical decision analysis examines the conditions that favor Patient A entering into the LDPE compared to directly accepting a kidney from their intended donor, as well as the circumstances where Patient B also benefits by accepting a lower-quality organ. RESULTS: Under select circumstances, a paired exchange could benefit both Patients A and B. For example, a 30-year-old Patient A with a lower-quality donor might gain 1.201.521.84 quality adjusted life years (QALYs) by entering into a LDPE for a better-quality kidney, whereas a 60-year-old Patient B might gain 0.931.031.13 QALYs by accepting Donor A's kidney rather than waiting longer in the LDPE. The net benefit (or loss) of entering the LDPE differs by recipient age, donor organ quality, likelihood of Patient B being transplanted in LDPE, and likelihood of Patient A finding an ideal donor in the LDPE. CONCLUSION: This study shows there are ways to increase live donor utilization and effectiveness that require further research and potentially changes to the LDPE process.

CONTEXTE: La transplantation d'un rein provenant d'un donneur vivant (DV) est la meilleure option pour les patients atteints d'insuffisance rénale terminale (IRT). Il est toutefois possible que ce ne soit pas la meilleure option lorsque le donneur est plus âgé et de beaucoup plus faible poids que le patient. Un patient (A) jumelé à un donneur moins qu'idéal (donneur A) pourrait être inscrit à un programme de dons croisés avec donneurs vivants (DCDV) dans l'espoir d'obtenir un organe plus approprié. Un deuxième patient (B), déjà inscrit au programme de DCDV, pourrait quant à lui bénéficier ou non de cet échange avec le donneur A. MÉTHODOLOGIE: Cette analyse des décisions médicales examine les conditions favorisant l'entrée du patient A dans le programme de DCDV comparativement à l'acceptation directe d'un rein du donneur prévu. On souhaitait également examiner les circonstances où un patient B bénéficie lui aussi de l'acceptation d'un organe de moindre qualité. RÉSULTATS: Dans certaines circonstances, un don croisé pourrait bénéficier aux deux patients. Par exemple, un patient de 30 ans (A) jumelé à un donneur de moins bonne qualité pourrait gagner 1,201,521,84 années de vie pondérée par la qualité (AVPQ) en entrant dans un programme de DCDV pour obtenir un rein de meilleure qualité, tandis qu'un patient de 60 ans (B) pourrait gagner 0, 931,031,13 AVPQ en acceptant le rein du donneur A plutôt que d'attendre plus longtemps dans le programme. Le bénéfice net (perte) d'une participation à un programme de DCDV diffère selon l'âge du receveur, la qualité de l'organe du donneur, la probabilité que le patient B soit transplanté dans le programme et la probabilité que le patient A trouve un donneur idéal dans le programme. CONCLUSION: Cette étude montre qu'il existe des moyens d'accroître l'utilisation et l'efficacité des donneurs vivants. Ces moyens nécessitent cependant des recherches plus poussées et de possibles changements dans le processus de dons croisés avec donneurs vivants.

Panic in the Pandemic: When Should Kidney Transplant Programs Close?

BACKGROUND: Pandemics greatly interfere with overall health care delivery as resources are diverted to combat the crisis. Kidney transplantation programs were closed temporarily during the COVID-19 pandemic. Given the critical shortage of organs, their short shelf life, and their overall importance to improving length and quality of life for those with kidney disease, this analysis examines the impact of discarding deceased donor organs. METHODS: The net benefit (or harm) of discarding deceased donor organs was measured in projected life years from a societal and individual perspective using a Markov model. A wide range of infection rates, pandemic durations, and case fatality rates associated with infection in wait listed and transplant recipients were examined. RESULTS: Overall, patient life expectancy fell for both wait listed and transplant recipients as the pandemic conditions became more unfavorable. However, the overall net benefit of a transplant during the pandemic was preserved. For example, prior to the pandemic, the net benefit of a kidney transplant over dialysis was calculated to be 6.25 life years (LYs) or 8.24 quality-adjusted life years (QALYs) in a 40-year old recipient. This fell to 5.86 LYs (7.78 QALYs) during the pandemic. Even assuming plausible but higher relative case fatality rates and risks of nosocomial and donor transmission in transplant recipients compared to wait listed patients, the net benefit remained >4 years for most deceased donor organs. CONCLUSION: As long as hospitals have adequate resources to deal with the pandemic and can limit nosocomial infection, kidney transplantation should not be curtailed.

The differential impact of size mismatch in live versus deceased donor kidney transplant.

BACKGROUND: The impact of weight mismatch between donors and recipients (D-R) undergoing living-donor kidney transplant (LDKT) versus weight-matched deceased donor kidney transplant (DDKT) is not established. AIM: To determine whether absolute weight mismatch between D-R affects graft survival following LDKT and how this relates to graft outcomes with DDKT when D-R are weight matched. MATERIALS & METHODS: We used multivariable Cox proportional hazards models and the Scientific Registry of Transplant Recipients to determine the association of weight-mismatched D-R (>50 kg, 30-50 kg or 10-30 kg ((D < R); (D > R) and <10 kg (D = R)) with death-censored graft failure in US LDKT recipients from 2006 to 2017. We also explored outcomes relative to weight-matched DDKT and finally, the impact of combined D-R weight-sex mismatch. RESULTS: In LDKT, the risk of graft loss was highest in the setting of D < R (HR 1.28, 95% CI 1.05-1.56 for >50 kg difference relative to D = R); however, this was still lower risk than weight-matched DDKT. D-R sex and combined weight-sex mismatch were only important for male recipients (HR 1.47, 95% CI 1.27-1.71 for a male recipient >30 kg larger than their female donor, relative to weight-matched male donor-male recipient). This remained superior to weight-sex-matched DDKT however. CONCLUSION: D-R weight-sex mismatch is important in LDKT; however, graft survival remains superior to proceeding with matched DDKT. Optimizing D-R matching in LDKT could be facilitated through a national kidney-paired donation registry. LDKT weight-sex mismatch should not be deferred in favor of DDKT.

Prevalence of Frailty in Patients Referred to the Kidney Transplant Waitlist.

Background: Comparisons between frailty assessment tools for waitlist candidates are a recognized priority area for kidney transplantation. We compared the prevalence of frailty using three established tools in a cohort of waitlist candidates. Methods: Waitlist candidates were prospectively enrolled from 2016 to 2020 across five centers. Frailty was measured using the Frailty Phenotype (FP), a 37-variable frailty index (FI), and the Clinical Frailty Scale (CFS). The FI and CFS were dichotomized using established cutoffs. Agreement was compared using κ coefficients. Area under the receiver operating characteristic (ROC) curves were generated to compare the FI and CFS (treated as continuous measures) with the FP. Unadjusted associations between each frailty measure and time to death or waitlist withdrawal were determined using an unadjusted Cox proportional hazards model. Results: Of 542 enrolled patients, 64% were male, 80% were White, and the mean age was 54±14 years. The prevalence of frailty by the FP was 16%. The mean FI score was 0.23±0.14, and the prevalence of frailty was 38% (score of ≥0.25). The median CFS score was three (IQR, 2-3), and the prevalence was 15% (score of ≥4). The κ values comparing the FP with the FI (0.44) and CFS (0.27) showed fair to moderate agreement. The area under the ROC curves for the FP and FI/CFS were 0.86 (good) and 0.69 (poor), respectively. Frailty by the CFS (HR, 2.10; 95% CI, 1.04 to 4.24) and FI (HR, 1.79; 95% CI, 1.00 to 3.21) was associated with death or permanent withdrawal. The association between frailty by the FP and death/withdrawal was not statistically significant (HR, 1.78; 95% CI, 0.79 to 3.71). Conclusion: Frailty prevalence varies by the measurement tool used, and agreement between these measurements is fair to moderate. This has implications for determining the optimal frailty screening tool for use in those being evaluated for kidney transplant.

Frailty and the Kidney Transplant Wait List: Protocol for a Multicenter Prospective Study.

BACKGROUND: Understanding how frailty affects patients listed for transplantation has been identified as a priority research need. Frailty may be associated with a high risk of death or wait-list withdrawal, but this has not been evaluated in a large multicenter cohort of Canadian wait-listed patients. OBJECTIVE: The primary objective is to evaluate whether frailty is associated with death or permanent withdrawal from the transplant wait list. Secondary objectives include assessing whether frailty is associated with hospitalization, quality of life, and the probability of being accepted to the wait list. DESIGN: Prospective cohort study. SETTING: Seven sites with established renal transplant programs that evaluate patients for the kidney transplant wait list. PATIENTS: Individuals who are being considered for the kidney transplant wait list. MEASUREMENTS: We will assess frailty using the Fried Phenotype, a frailty index, the Short Physical Performance Battery, and the Clinical Frailty Scale at the time of listing for transplantation. We will also assess frailty at the time of referral to the wait list and annually after listing in a subgroup of patients. METHODS: The primary outcome of the composite of time to death or permanent wait-list withdrawal will be compared between patients who are frail and those who are not frail and will account for the competing risks of deceased and live donor transplantation. Secondary outcomes will include number of hospitalizations and length of stay, and in a subset, changes in frailty severity over time, change in quality of life, and the probability of being listed. Recruitment of 1165 patients will provide >80% power to identify a relative hazard of ≥1.7 comparing patients who are frail to those who are not frail for the primary outcome (2-sided α = .05), whereas a more conservative recruitment target of 624 patients will provide >80% power to identify a relative hazard of ≥2.0. RESULTS: Through December 2019, 665 assessments of frailty (inclusive of those for the primary outcome and all secondary outcomes including repeated measures) have been completed. LIMITATIONS: There may be variation across sites in the processes of referral and listing for transplantation that will require consideration in the analysis and results. CONCLUSIONS: This study will provide a detailed understanding of the association between frailty and outcomes for wait-listed patients. Understanding this association is necessary before routinely measuring frailty as part of the wait-list eligibility assessment and prior to ascertaining the need for interventions that may modify frailty. TRIAL REGISTRATION: Not applicable as this is a protocol for a prospective observational study.

CONTEXTE: La compréhension de l'incidence de la fragilité sur les patients en attente d'une greffe rénale a été désignée comme un besoin prioritaire de recherche. La fragilité pourrait être associée à un risque élevé de mortalité ou de se voir retiré de la liste d'attente pour une transplantation, mais elle n'a jamais été évaluée dans une vaste cohorte multicentrique de patients canadiens en attente d'une greffe. OBJECTIFS: Le principal objectif consiste à déterminer si la fragilité d'un patient l'expose à un plus grand risque de décès ou de retrait permanent de la liste d'attente pour une greffe. Nous souhaitons également vérifier s'il existe un lien entre la fragilité et le nombre d'hospitalisations, la qualité de vie et la probabilité d'être accepté sur la liste d'attente. TYPE D'ÉTUDE: Étude de cohorte prospective. CADRE: Sept sites disposant d'un programme de transplantation rénale évaluant les patients en vue de leur inscription sur la liste d'attente pour une greffe. SUJETS: Des candidats à la liste d'attente pour une transplantation rénale. MESURES: La fragilité sera évaluée à l'aide du Phénotype de Fried (un indice de la fragilité), du test SPPB (Short Physical Performance Battery) et de l'échelle Clinical Frailty Scale au moment de l'inscription sur la liste d'attente pour une transplantation. Nous mesurerons la fragilité des patients de leur orientation vers le programme jusqu'à leur inscription sur la liste, puis sur une base annuelle après leur inclusion dans un sous-groupe de patients. MÉTHODOLOGIE: Le résultat principal, soit un composite du délai avant le décès ou le retrait permanent de la liste, sera comparé entre les patients fragiles et non fragiles, et tiendra compte des risques concurrents découlant de la transplantation selon que l'organe provient d'un donneur vivant ou décédé. Les résultats secondaires comprendront le nombre d'hospitalisations et leur durée, les variations de la fragilité et de la qualité de vie au fil du temps (pour un sous-groupe de patients), de même que les probabilités d'être inscrit sur la liste d'attente. Le recrutement de 1 165 patients nous permettrait d'obtenir un risque relatif d'au moins 1,7 dans plus de 80 % des cas lors de la comparaison des patients fragiles à ceux qui ne le sont pas pour le résultat principal (double erreur alpha = 0,05), alors que ce risque relatif serait de 2,0 avec un objectif de recrutement plus conservateur de 624 patients. RÉSULTATS: Un total de 665 évaluations de la fragilité (tant pour le résultat primaire que pour les résultats secondaires, y compris les mesures répétitives) a été complété en décembre 2019. LIMITES: Les résultats et leur analyse devront tenir compte des possibles variations entre les différents sites en ce qui concerne les processus d'aiguillage et d'inscription sur les listes d'attente pour une greffe. CONCLUSION: Cette étude fournira une compréhension détaillée de l'association entre la fragilité et les résultats cliniques pour les patients en attente d'une greffe. La compréhension de cette association est nécessaire avant d'inclure systématiquement la mesure de la fragilité au processus d'évaluation de l'admissibilité à la liste d'attente et avant d'établir le besoin de procéder à des interventions susceptibles de modifier la fragilité du patient.

Canadian Society of Nephrology Commentary on the Kidney Disease Improving Global Outcomes 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder.

PURPOSE OF REVIEW: (1) To provide commentary on the 2017 update to the Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD); (2) to apply the evidence-based guideline update for implementation within the Canadian health care system; (3) to provide comment on the care of children with chronic kidney disease (CKD); and (4) to identify research priorities for Canadian patients. SOURCES OF INFORMATION: The KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of CKD-MBD. METHODS: The commentary committee co-chairs selected potential members based on their knowledge of the Canadian kidney community, aiming for wide representation from relevant disciplines, academic and community centers, and different geographical regions. KEY FINDINGS: We agreed with many of the recommendations in the clinical practice guideline on the diagnosis, evaluation, prevention, and treatment of CKD-MBD. However, based on the uncommon occurrence of abnormalities in calcium and phosphate and the low likelihood of severe abnormalities in parathyroid hormone (PTH), we recommend against screening and monitoring levels of calcium, phosphate, PTH, and alkaline phosphatase in adults with CKD G3. We suggest and recommend monitoring these parameters in adults with CKD G4 and G5, respectively. In children, we agree that monitoring for CKD-MBD should begin in CKD G2, but we suggest measuring ionized calcium, rather than total calcium or calcium adjusted for albumin. With regard to vitamin D, we suggest against routine screening for vitamin D deficiency in adults with CKD G3-G5 and G1T-G5T and suggest following population health recommendations for adequate vitamin D intake. We recommend that the measurement and management of bone mineral density (BMD) be according to general population guidelines in CKD G3 and G3T, but we suggest against routine BMD testing in CKD G4-G5, CKD G4T-5T, and in children with CKD. Based on insufficient data, we also recommend against routine bone biopsy in clinical practice for adults with CKD or CKD-T, or in children with CKD, although we consider it an important research tool. LIMITATIONS: The committee relied on the evidence summaries produced by KDIGO. The CSN committee did not replicate or update the systematic reviews.

JUSTIFICATION: (1) Commenter les recommandations du KDIGO 2017 (Kidney Disease Improving Global Outcomes) sur les bonnes pratiques cliniques pour le diagnostic, l'évaluation et le traitement des troubles du métabolisme minéral osseux associés aux maladies rénales chroniques (TMO-MRC); (2) appliquer les lignes directrices actualisées et fondées sur les données probantes en vue de leur mise en œuvre dans le système de soins de santé canadien; (3) commenter les soins prodigués aux enfants atteints d'insuffisance rénale chronique (IRC) et (4) définir les priorités de recherche des patients Canadiens. SOURCES: Les recommandations du KDIGO 2017 (Kidney Disease Improving Global Outcomes) sur les bonnes pratiques cliniques pour le diagnostic, l'évaluation et le traitement des troubles du métabolisme minéral osseux associés aux maladies rénales chroniques (TMO-MRC). MÉTHODOLOGIE: Les coprésidents du comité ont sélectionné les membres potentiels sur la base de leur connaissance du secteur de la santé rénale au Canada, tout en visant une bonne représentation de toutes les disciplines concernées, des centres universitaires et communautaires et des différentes régions géographiques. PRINCIPAUX COMMENTAIRES: Nous approuvons un grand nombre des recommandations du KDIGO. Cependant, compte tenu de la rareté des anomalies du calcium et du phosphate et de la faible probabilité d'anomalies graves de la PTH (hormone parathyroïde), nous déconseillons le dépistage et la surveillance des taux de calcium, de phosphate, de PTH et de phosphatase alcaline chez les adultes atteints d'IRC de stade G3. Nous suggérons de mesurer ces paramètres chez les adultes de stade G4 et nous le recommandons pour les patients de stade G5. Chez les enfants, nous appuyons la recommandation de commencer la surveillance des TMO-MRC dès le stade G2, mais nous suggérons de mesurer le calcium ionisé plutôt que les taux de calcium total ou de calcium corrigé en fonction de l'albumine. En ce qui concerne la vitamine D, nous déconseillons le dépistage de routine des carences chez les adultes atteints d'IRC de stade G3 à G5 et G1T à G5T; nous suggérons plutôt de suivre les recommandations visant la population générale pour un apport adéquat en vitamine D. Nous recommandons que la mesure et la prise en charge de la densité minérale osseuse (DMO) se fassent en suivant les recommandations pour la population générale chez les adultes atteints d'IRC de stade G3 et G3T, mais nous déconseillons les tests de DMO de routine chez les adultes de stades G4-G5 et G4T-G5T, de même que chez les enfants atteints d'IRC. En raison de données insuffisantes, nous déconseillons également la pratique systématique d'une biopsie osseuse chez les adultes atteints d'IRC ou d'IRC-TMO, ainsi que chez les enfants atteints d'IRC, bien que nous la considérions comme un important outil de recherche. LIMITES: Le comité s'est appuyé sur le résumé des preuves rédigé par le KDIGO. Le comité de la SCN n'a pas reproduit ou mis à jour les revues systématiques.

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.

JUSTIFICATION: Examiner une directive internationale sur l'évaluation et la prise en charge des donneurs vivants d'un rein et formuler un commentaire sur l'applicabilité de ces recommandations à la population des donneurs canadiens. SOURCES: Nous avons révisé le guide des pratiques cliniques relatives à l'évaluation et à la prise en charge des donneurs vivants d'un rein (Clinical Practice Guideline for Evaluation and Care of Living Kidney Donors) de 2017 du KDIGO (Kidney Disease: Improving Global Outcomes) et nous l'avons comparé aux recommandations canadiennes de 2014 du Protocole de don croisé d'un rein par donneurs participants (Kidney Paired Donation Protocol for Participating Donors). MÉTHODOLOGIE: Un groupe de travail réunissant des membres de la Société canadienne de transplantation et de la Société canadienne de néphrologie a été formé. Les membres ont été sélectionnés pour représenter tout le Canada et plusieurs sous-spécialisations relatives au don vivant d'un rein, notamment la néphrologie, la chirurgie, la transplantation, la pédiatrie et l'éthique. PRINCIPALES CONSTATATIONS: Plusieurs des recommandations du KDIGO s'harmonisent aux recommandations du protocole de don croisé d'un rein. Les chercheurs canadiens ont contribué en grande partie aux données sur l'évaluation des donneurs et des résultats utilisées pour appuyer les recommandations formulées dans les lignes directrices du KDIGO. LIMITES: Certains résultats et outils d'évaluation des risques doivent encore être validés dans la population des donneurs canadiens. CONCLUSION: Compte tenu des plus récentes données, les donneurs vivants d'un rein devraient être mis en garde concernant les risques sur leur santé post-don, tout en comprenant les limites de la littérature en ce qui concerne leur généralisabilité à la population de donneurs canadiens.

Prolonged Cold Ischemia Time Offsets the Benefit of Human Leukocyte Antigen Matching in Deceased Donor Kidney Transplant.

BACKGROUND: The consequences of prolonging cold ischemia time (CIT) to facilitate HLA matching in kidney transplantation are not known. METHODS: Patients with a history of kidney transplant in the United States (2000-2016) with 0 HLA mismatch (MM) were categorized based on CIT (< 10; 10 to < 15; 15 to < 20; 20 to < 25; 25 to < 30; and ≥ 30 hours). Time to graft loss was compared for each CIT category to a reference group of individuals with > 0 HLA MM and short CIT (< 10 hours) using a multivariable Cox proportional hazards model. RESULTS: The adjusted risk of graft failure was significantly lower for 0 HLA MM with the shortest CIT compared to the reference group (hazard ratio, 0.82; 95% confidence interval, 0.72-0.94), and this survival advantage persisted to a threshold of < 20 hours of CIT. No survival advantage was observed for the 0 HLA MM group once CIT was > 20 hours. This trend persisted after excluding highly sensitized recipients (panel reactive antibody > 98%) where shipping of organs occurs to achieve more equitable access to organs rather than optimize HLA match. CONCLUSIONS: CIT > 20 hours offsets the benefit of 0 HLA MM in kidney transplantation. This may have implications in organ shipping to facilitate immunologic match.