The benefit to waitlist patients in a national paired kidney exchange program: Exploring characteristics of chain end living donor transplants

Nondirected kidney donors can initiate living donor chains that end to patients on the waitlist. We compared 749 National Kidney Registry (NKR) waitlist chain end transplants to other transplants from the NKR and the Scientific Registry of Transplant Recipients between February 2008 and September 2020. Compared to other NKR recipients, chain end recipients were more often older (53 vs. 52 years), black (32% vs. 15%), publicly insured (71% vs. 46%), and spent longer on dialysis (3.0 vs. 1.0 years). Similar differences were noted between chain end recipients and non-NKR living donor recipients. Black patients received chain end kidneys at a rate approaching that of deceased donor kidneys (32% vs. 34%). Chain end donors were older (52 vs. 44 years) with slightly lower glomerular filtration rates (93 vs. 98 ml/min/1.73 m²) than other NKR donors. Chain end recipients had elevated risk of graft failure and mortality compared to control living donor recipients (both p < .01) but lower graft failure (p = .03) and mortality (p < .001) compared to deceased donor recipients. Sharing nondirected donors among a multicenter network may improve the diversity of waitlist patients who benefit from living donation.     

Your Path to Transplant: A randomized controlled trial of a tailored expert system intervention to increase knowledge,attitudes, and pursuit of kidney transplant

Individually tailoring education over time may help more patients, especially racial/ethnic minorities, get waitlisted and pursue deceased and living donor kidney transplant (DDKT and LDKT, respectively). We enrolled 802 patients pursuing transplant evaluation at the University of California, Los Angeles Transplant Program into a randomized education trial. We compared the effectiveness of Your Path to Transplant (YPT), an individually tailored coaching and education program delivered at 4 time points, with standard of care (SOC) education on improving readiness to pursue DDKT and LDKT, transplant knowledge, taking 15 small transplant-related actions, and pursuing transplant (waitlisting or LDKT rates) over 8 months. Survey outcomes were collected prior to evaluation and at 4 and 8 months. Time to waitlisting or LDKT was assessed with at least 18 months of follow-up. At 8 months, compared to SOC, the YPT group demonstrated increased LDKT readiness (47% vs 33%, P = .003) and transplant knowledge (effect size [ES] = 0.41, P < .001). Transplant pursuit was higher in the YPT group (hazard ratio: 1.44, 95% confidence interval: 1.15-1.79, P = .002). A focused, coordinated education effort can improve transplant-seeking behaviors and waitlisting rates. ClinicalTrials.gov registration: NCT02181114.     

Quantifying infection risks in incompatible living donor kidney transplant recipients

Desensitization has enabled incompatible living donor kidney transplantation (ILDKT) across HLA/ABO barriers, but added immunomodulation might put patients at increased risk of infections. We studied 475 recipients from our center from 2010 to 2015, categorized by desensitization intensity: none/compatible (n = 260), low (0-4 plasmaphereses, n = 47), moderate (5-9, n = 74), and high (≥10, n = 94). The 1-year cumulative incidence of infection was 50.1%, 49.8%, 66.0%, and 73.5% for recipients who received none, low, moderate, and high-intensity desensitization (P < .001). The most common infections were UTI (33.5% of ILDKT vs. 21.5% compatible), opportunistic (21.9% vs. 10.8%), and bloodstream (19.1% vs. 5.4%) (P < .001). In weighted models, a trend toward increased risk was seen in low (wIRR = _0.771.40_2.56,P = .3) and moderately (wIRR = _0.881.35_2.06,P = .2) desensitized recipients, with a statistically significant 2.22-fold (wIRR = _1.332.22_3.72,P = .002) increased risk in highly desensitized recipients. Recipients with ≥4 infections were at higher risk of prolonged hospitalization (wIRR = _2.623.57_4.88, P < .001) and death-censored graft loss (wHR = _1.154.01_13.95,P = .03). Post–KT infections are more common in desensitized ILDKT recipients. A subset of highly desensitized patients is at ultra-high risk for infections. Strategies should be designed to protect patients from the morbidity of recurrent infections, and to extend the survival benefit of ILDKT across the spectrum of recipients.     

Factors associated with perceived donation‐related financial burden among living kidney donors

The perception of living kidney donation–related financial burden affects willingness to donate and the experience of donation, yet no existing tools identify donors who are at higher risk of perceived financial burden. We sought to identify characteristics that predicted higher risk of perceived financial burden. We surveyed 51 living kidney donors (LKDs) who donated from 01/2015 to 3/2016 about socioeconomic characteristics, predonation cost concerns, and perceived financial burden. We tested associations between both self‐reported and ZIP code–level characteristics and perceived burden using Fisher's exact test and bivariate modified Poisson regression. Donors who perceived donation‐related financial burden were less likely to have an income above their ZIP code median (14% vs. 72%, P = .006); however, they were more likely than donors who did not perceive burden to rent their home (57% vs. 16%, P = .03), have an income <$60 000 (86% vs. 20%, P = .002), or have had predonation cost concerns (43% vs. 7%, P = .03). Perceived financial burden was 3.6‐fold as likely among those with predonation cost concerns and 10.6‐fold as likely for those with incomes <$60 000. Collecting socioeconomic characteristics and asking about donation‐related cost concerns prior to donation might allow transplant centers to target financial support interventions toward potential donors at higher risk of perceiving donation‐related financial burden.     

Epidemiology of end‐stage renal failure among twins and diagnosis,management, and current outcomes of kidney transplantation between identical twins

The aim of the study is to provide a comprehensive overview of identical twin kidney transplantation in the modern era. We provide epidemiologic trends in the US twin population from 1959 to 2000, current methods to identify zygosity, outcomes for identical twin transplants, and a comprehensive management strategy for identical twin kidney transplantation. By 2019, we project that 433 010 dizygotic and monozygotic twins will be alive and at risk for developing ESRF. Monozygosity between a donor‐recipient pair can be confirmed by concordance in sex, blood type, and HLA antigen match with precision testing using 13/17 Short Tandem Repeat sequencing to a likelihood of nearly 100%. Among identical twin transplants from 2001 to 2017, excellent patient and kidney graft survival rates were noted. Approximately 50% of kidney transplant recipients of identical twins transplant did not receive maintenance immunosuppression, and no differences in graft survival were noted among patients with and without immunosuppression at 6 and 12 months (P = .8 and .7). Patients with glomerulonephritis as the cause of ESRF had lower graft survival (P = .06) suggesting that recurrent glomerulonephritis as a likely cause of graft loss among these recipients.     

Quantifying lead time bias when estimating patient survival in preemptive living kidney donor transplantation

Preemptive kidney transplantation is the preferred initial renal replacement therapy, by avoiding dialysis and reportedly maximizing patient survival. Lead time bias may account for some or all of the observed survival advantage, but the impact of this has not been quantified. Using the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, we included adult recipients of living donor kidney transplants during 1998‐2017. Patients were transplanted preemptively (n = 1435) or after receiving up to 6 months of dialysis (n = 712). We created a matched cohort using propensity scores, and accounted for lead time (dialysis and estimated predialysis) using left‐truncated Cox models with the primary outcome of patient survival. The median eGFR at transplantation was 6.9 mL/min per 1.73 m² in the non‐pre‐emptive, and 9.6 mL/min per 1.73 m² in the preemptive group. In the matched cohort (n = 1398), preemptive transplantation was not associated with a survival advantage hazard ratio (HR) for preemptive vs non‐pre‐emptive 1.12 (95% confidence interval [CI] 0.79‐1.61). Accounting for lead time moved the point estimates toward a survival disadvantage for preemptive transplantation (eg, HR assuming 4 mL/min per 1.73 m²/year eGFR decline, 1.21 [0.85, 1.73]), but in all cases the 95% CIs crossed 1. The optimal timing of preemptive living donor kidney transplantation requires further study.     

A randomized,phase 1b study of the pharmacokinetics,pharmacodynamics, safety,and tolerability of bleselumab,a fully human,anti‐CD40 monoclonal antibody,in kidney transplantation

This study evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of various doses of the anti‐CD40 monoclonal antibody bleselumab (ASKP1240) in de novo kidney transplant recipients receiving concomitant standard immunosuppression over 90 days posttransplant. Transplant recipients were randomized (1:1:1:1:1) to bleselumab 50 mg, 100 mg, 200 mg, or 500 mg, or placebo, in addition to standard maintenance immunosuppression. The primary pharmacokinetic endpoints were AUC_inf, C_max, and AUC_last. The primary pharmacodynamic endpoint was B cell CD40 receptor occupancy over time. Overall, 50 kidney transplant recipients were randomized; 45 received their randomized treatment (bleselumab [n = 37] or placebo [n = 8]). AUC_inf and AUC_last demonstrated a more than dose‐proportional increase in the range of 50‐500 mg, and C_max increased linearly with increasing dose. Maximal receptor occupancy for B cell CD40 was reached at all dose levels and was prolonged as dose increased. No kidney transplant recipients experienced cytokine release syndrome or a thromboembolic event. Treatment‐emergent anti‐bleselumab antibodies were found in one kidney transplant recipient in the bleselumab 50 mg group; these were detected only at Day 7. Overall, bleselumab demonstrated nonlinear pharmacokinetics and dose‐dependent prolonged B cell CD40 receptor occupancy and was well tolerated at all doses (ClinicalTrials.gov: NCT01279538).     

Panniculectomy at the time of living donor renal transplantation: An 8‐year experience

Panniculectomy can be performed as a prophylactic procedure preceding transplantation to enable obese patients to meet criteria for renal transplantation. No literature exists on combined renal transplant and panniculectomy surgery (LRT‐PAN). We describe our 8‐year experience performing LRT‐PAN. A retrospective chart review of all patients who had undergone LRT‐PAN from 2010 to 2018 was conducted. Data were collected on patient demographics, allograft survival and function, and postoperative course. Fifty‐eight patients underwent LRT‐PAN. All grafts survived, with acceptable function at 1 year. Median length of stay was 4 days with a mean operative duration of 363 minutes. The wound complication rate was 24%. Ninety‐day readmission rate was 52%, with medical causes as the most common reason for readmission (45%), followed by wound (32%) and graft‐related complications (23%). Body mass index, diabetes status, and previous immunosuppression did not influence wound complication rate or readmission (P = .7720, P = .0818, and P = .4830, respectively). Combining living donor renal transplant and panniculectomy using a multidisciplinary team may improve access to transplantation, particularly for the obese and postobese population. This combined approach yielded shorter‐than‐expected hospital stays and similar wound complication rates, and thus should be considered for patients in whom transplantation might otherwise be withheld on the basis of obesity.     

Associations of perceived information adequacy and knowledge with pursuit of live donor kidney transplants and living donor inquiries among African American transplant candidates

We studied associations between perceived adequacy of live donor kidney transplant (LDKT) information or knowledge with pursuit of LDKT or receipt of live donor inquiries among 300 African American kidney transplant candidates. Participants reported via questionnaire how informed or knowledgeable they felt regarding LDKT. Participants also reported their pursuit of LDKT, categorized as “low” (no discussion with family or friends about LDKT and no identified donor), “intermediate” (discussed LDKT with family but no identified donor) or “high” (discussed LDKT with family and identified a potential donor). We reviewed participants' electronic health records to identify potential donors' transplant center inquiries on participants' behalves. A minority of participants reported they felt “very” or “extremely” well informed about LDKT (39%) or had “a great deal” of LDKT knowledge (38%). Participants perceiving themselves as “very” or “extremely” (vs “not” or “slightly”) well informed about LDKT had statistically significantly greater odds of intermediate or high (vs low) pursuit of LDKT (odds ratio [95% confidence interval] 2.71 [1.02-7.17]). Perceived LDKT knowledge was not associated with pursuit of LDKT. Neither perceived information adequacy nor knowledge was associated with living donor inquiries. Efforts to better understand the role of education in the pursuit of LDKT among African American transplant candidates are needed.     

Inferior long‐term allograft and patient outcomes among recipients of offspring living donor kidneys

While offspring‐to‐parent living donor kidney transplantations may represent an ideal donor–recipient combination to optimize long‐term transplantation outcomes, the sex‐specific long‐term success of these transplantations remains unclear. We hypothesize that allograft and recipient survivals in offspring‐to‐parent living donor kidney transplantation differ between men and women due to donor‐specific alloimmunization during pregnancy. We retrospectively analyzed long‐term allograft and patient survival among men and women who received an offspring living donor kidney compared with those who received other haplotype‐matched living donor kidneys. Based on multivariable Cox proportional hazards modeling of Organ Procurement and Transplantation Network data from 2001 to 2015, we found that both men and women who received offspring living donor kidneys had significantly increased mortality compared with recipients who received nonoffspring living donor kidneys. While male recipients of any living donor kidney had greater risk of mortality and allograft failure than female recipients, there was no significant difference in all‐cause allograft failure or mortality in male versus female recipients of offspring living donor kidney transplantations. Our analysis demonstrated no significant interaction between recipient sex and donor offspring status. We conclude that nonoffspring living donors should be considered whenever feasible for both men and women with multiple donor options.     

Multiple myeloma derived from a kidney transplant donor who also developed myeloma after kidney donation

Patients who undergo kidney transplantation are at increased risk of cancer due to the long‐term use of immunosuppressive treatment. Postrenal transplant cancers usually originate from recipient cells, but donor‐related cancers have been rarely reported. We report the case of 49‐year‐old woman who developed multiple myeloma of donor origin 7 years after kidney transplantation. The donor was the mother of the recipient and also developed multiple myeloma 1 year after kidney donation. The diagnosis of multiple myeloma was based on IgG lambda monoclonal protein and the infiltration of plasma cells in bone marrow. The renal biopsy did not reveal plasmacytoma in the transplanted kidney. Epstein‐Barr virus DNA load was negative in peripheral blood. The patient responded to lenalidomide and dexamethasone, and subsequently received autologous stem cell transplantation. Donor chimerism was detected in the recipient marrow by short tandem repeat analysis; however, studies of Ig gene rearrangement were inconclusive due to insufficient DNA quality. The chromosomal abnormalities in the two myelomas were different. This case suggests that donor cells with myeloma‐initiating potential can be transferred to a recipient via a renal graft and can lead to the development of donor‐derived multiple myeloma in the recipient under immunosuppression.     

Temporal trends,center‐level variation,and the impact of prevalent state obesity rates on acceptance of obese living kidney donors

The impact of pre‐donation obesity on long‐term outcomes of living kidney donors remains controversial. Published guidelines offer varying recommendations regarding BMI (kg/m²) thresholds for donor acceptance. We examined temporal and center‐level variation in BMI of accepted donors across US transplant centers. Using national transplant registry data, we performed multivariate hierarchical logistic regression modeling using pairwise comparisons (overweight, BMI: 25‐29.9; mildly obese, BMI: 30‐34.9; very obese, BMI: ≥35; versus normal BMI: 18.5‐24.9). Metrics of heterogeneity, including median odds ratio (MOR), were calculated. Among 90 013 living kidney donors, 2001‐2016, proportions who were very obese decreased and proportions who were mildly obese or overweight increased. Significant center‐level heterogeneity was noted in BMI of accepted donors; the MOR varied from 1.10 for overweight to 1.93 for very obese donors. At centers located in the 10 states with the highest general population obesity rates, adjusted odds of very obese donor status were 185% higher (reference: normal BMI) than in states with the lowest obesity rates. Although there is a declining trend in acceptance of very obese living kidney donors, variation across centers is significant. Furthermore, local population obesity rates may affect the decision to accept obese individuals as donors.     

Better graft outcomes from offspring donor kidneys among living donor kidney transplant recipients in the United States

A recent study reported that kidney transplant recipients of offspring living donors had higher graft loss and mortality. This seemed counterintuitive, given the excellent HLA matching and younger age of offspring donors; we were concerned about residual confounding and other study design issues. We used Scientific Registry of Transplant Recipients data 2001‐2016 to evaluate death‐censored graft failure (DCGF) and mortality for recipients of offspring versus nonoffspring living donor kidneys, using Cox regression models with interaction terms. Recipients of offspring kidneys had lower DCGF than recipients of nonoffspring kidneys (15‐year cumulative incidence 21.2% vs 26.1%, P < .001). This association remained after adjustment for recipient and transplant factors (adjusted hazard ratio [aHR] = _0.730.77_0.82, P < .001), and was attenuated among African American donors (aHR _0.770.85_0.95; interaction: P = .01) and female recipients (aHR _0.770.84_0.91, P < .001). Although offspring kidney recipients had higher mortality (15‐year mortality 56.4% vs 37.2%, P < .001), this largely disappeared with adjustment for recipient age alone (aHR = _1.021.06_1.10, P = .002) and was nonsignificant after further adjustment for other recipient characteristics (aHR = _0.930.97_1.01, P = .1). Kidneys from offspring donors provided lower graft failure and comparable mortality. An otherwise eligible donor should not be dismissed because they are the offspring of the recipient, and we encourage continued individualized counseling for potential donors.     

The landscape of international living kidney donation in the United States

In the United States, kidney donation from international (noncitizen/nonresident) living kidney donors (LKDs) is permitted; however, given the heterogeneity of healthcare systems, concerns remain regarding the international LKD practice and recipient outcomes. We studied a US cohort of 102 315 LKD transplants from 2000‐2016, including 2088 international LKDs, as reported to the Organ Procurement and Transplantation Network. International LKDs were more tightly clustered among a small number of centers than domestic LKDs (Gini coefficient 0.76 vs 0.58, P < .001). Compared with domestic LKDs, international LKDs were more often young, male, Hispanic or Asian, and biologically related to their recipient (P < .001). Policy‐compliant donor follow‐up was substantially lower for international LKDs at 6, 12, and 24 months postnephrectomy (2015 cohort: 45%, 33%, 36% vs 76%, 71%, 70% for domestic LKDs, P < .001). Among international LKDs, Hispanic (aOR = _0.230.36_0.56, P < .001) and biologically related (aOR = _0.390.59_0.89, P < .01) donors were more compliant in donor follow‐up than white and unrelated donors. Recipients of international living donor kidney transplant (LDKT) had similar graft failure (aHR = _0.780.89_1.02, P = .1) but lower mortality (aHR = _0.530.62_0.72, P < .001) compared with the recipients of domestic LDKT after adjusting for recipient, transplant, and donor factors. International LKDs may provide an alternative opportunity for living donation. However, efforts to improve international LKD follow‐up and engagement are warranted.     

Prospective,double‐blind,randomized clinical trial comparing an ERAS pathway with ketorolac and pregabalin versus standard of care plus placebo during live donor nephrectomy for kidney transplant

Opioid exposure is a concern after live donation for kidney transplant. We theorized that an enhanced recovery after surgery pathway (ERAS) using pregabalin preoperatively to desensitize nerves followed by the nonsteroidal anti‐inflammatory drug ketorolac, during and after surgery, can control pain, thus requiring less perioperative narcotics. The aim of this study was to determine if the use of a nonopioid analgesic ERAS protocol for donor nephrectomies could decrease the use of narcotics without an increase in complications compared with standard of care (SOC). This is a single‐center, prospective, double‐blind, randomized clinical trial involving a total of 62 patients undergoing nephrectomy for live donor kidney transplant. Length of hospital stay (LOS) was significantly reduced by 10% in the ERAS group versus the SOC‐plus‐placebo group. Morphine dose equivalents were significantly reduced by 40% in the study group versus the SOC‐plus‐placebo group. The use of this nonopioid analgesic ERAS pathway for donor nephrectomies decreased the use of narcotics without an increase in complications compared with SOC. There was significantly reduced LOS and less narcotic use in the study group versus the SOC‐plus‐placebo group. (ClinicalTrials.gov registration number: NCT03669081).     

Impact of kidney transplantation on sleep apnea severity: A prospective polysomnographic study

Fluid overload has been associated with a high prevalence of sleep apnea (SA) in patients with end‐stage kidney disease (ESKD). In this prospective study, we hypothesized that improvement in kidney function and hydration status after kidney transplantation (Tx) may result in an improvement in SA severity. A total of 196 patients on the kidney Tx waiting list were screened for SA using home nocturnal polysomnography (PSG) to measure the apnea‐hypopnea index (AHI) and underwent bioimpedance to assess body composition. Of 88 participants (44.9%) with SA (AHI ≥ 15/h), 42 were reassessed 6 months post‐Tx and were compared with 27 control patients. There was a significant, but small, post‐Tx improvement in AHI (from 44.2 ± 24.3 to 34.7 ± 20.9/h, P = .02) that significantly correlated with a reduction in fluid overload (from 1.8 ± 2.0 to 1.2 ± 1.2 L, P = .02) and body water (from 54.9% to 51.6%, P = .003). A post‐Tx increase in body fat mass (from 26% to 30%, P = .003) possibly blunted the beneficial impact of kidney Tx on SA. All parameters remained unchanged in the control group. In conclusion, SA is a frequent condition in ESKD patients and partially improved by kidney Tx. We suggest that SA should be systematically assessed before and after kidney Tx. ClinicalTrials.gov Identifier: NCT02020642.     

A donor risk index for graft loss in pediatric living donor kidney transplantation

Pediatric kidney transplant candidates often have multiple potential living donors (LDs); no evidence‐based tool exists to compare potential LDs, or to decide between marginal LDs and deceased donor (DD) kidney transplantation (KT). We developed a pediatric living kidney donor profile index (P‐LKDPI) on the same scale as the DD KDPI by using Cox regression to model the risk of all‐cause graft loss as a function of living donor characteristics and DD KDPI. HLA‐B mismatch (adjusted hazard ratio [aHR] per mismatch = _1.041.27_1.55), HLA‐DR mismatch (aHR per mismatch = _1.021.23_1.49), ABO incompatibility (aHR = _1.203.26_8.81), donor systolic blood pressure (aHR per 10 mm Hg = _1.011.07_1.18), and donor estimated GFR (eGFR; aHR per 10 mL/min/1.73 m² = _0.880.94_0.99) were associated with graft loss after LDKT. Median (interquartile range [IQR]) P‐LKDPI was ?25 (?56 to 12). 68% of donors had P‐LKDPI <0 (less risk than any DD kidney) and 25% of donors had P‐LKDPI >14 (more risk than median DD kidney among pediatric KT recipients during the study period). Strata of LDKT recipients of kidneys with higher P‐LKDPI had a higher cumulative incidence of graft loss (39% at 10 years for P‐LDKPI ≥20, 28% for 20> P‐LKDPI ≥?20, 23% for ?20 > P‐LKDPI ≥?60, 19% for P‐LKDPI <?60 [log rank P < .001]). The P‐LKDPI can aid in organ selection for pediatric KT recipients by allowing comparison of potential LD and DD kidneys.     

Immune responses following tocilizumab therapy to desensitize HLA-sensitized kidney transplant candidates

Kidney transplant candidates (KTCs) who are HLA highly sensitized (calculated panel-reactive alloantibodies >95%) have poor access to deceased kidney transplantation. In this single-center prospective study, 13 highly sensitized desensitization-naïve KTCs received IV tocilizumab (8 mg/kg) every 4 weeks. We evaluated tolerability as well as immune responses, that is, T cell, B cell, T follicular helper (Tfh) subsets, blood cytokines (IL-6, soluble IL-6 receptor-sIL-6R-, IL-21), blood chemokines (CXCL10, CXCL13), and anti-HLA alloantibodies. Tocilizumab treatment was well-tolerated except in one patient who presented spondylodiscitis, raising a note of caution. Regarding immune parameters, there were no significant changes of percentages of lymphocyte subsets, that is, CD3⁺, CD3⁺/CD4⁺, CD3⁺/CD8⁺ T cells, and NK cells. This was also the case for Tfh cell subsets, B cells, mature B cells, plasma cells, pre-germinal center (GC) B cells, and post-GC B cells, whereas we observed a significant increase in naïve B cells (p = .02) and a significant decrease in plasmablasts (p = .046) over the tocilizumab treatment course. CXCL10, CXCL13, IL-21, total IgG, IgA, and IgM levels did not significantly change during tocilizumab therapy; conversely, there was a significant increase in IL-6 levels (p = .03) and a huge increase in sIL-6R (p = .00004). There was a marginal effect on anti-HLA alloantibodies (class I and class II). To conclude in highly sensitized KTCs, tocilizumab as a monotherapy limited B cell maturation; however, it had almost no effect on anti-HLA alloantibodies.