Characterizing the risk of human leukocyte antigen-incompatible living donor kidney transplantation in older recipients.

Older compatible living donor kidney transplant (CLDKT) recipients have higher mortality and death-censored graft failure (DCGF) compared to younger recipients. These risks may be amplified in older incompatible living donor kidney transplant (ILDKT) recipients who undergo desensitization and intense immunosuppression. In a 25-center cohort of ILDKT recipients transplanted between September 24, 1997, and December 15, 2016, we compared mortality, DCGF, delayed graft function (DGF), acute rejection (AR), and length of stay (LOS) between 234 older (age ≥60 years) and 1172 younger (age 18-59 years) recipients. To investigate whether the impact of age was different for ILDKT recipients compared to 17 542 CLDKT recipients, we used an interaction term to determine whether the relationship between posttransplant outcomes and transplant type (ILDKT vs CLDKT) was modified by age. Overall, older recipients had higher mortality (hazard ratio: 1.632.072.65, P < .001), lower DCGF (hazard ratio: 0.360.530.77, P = .001), and AR (odds ratio: 0.390.540.74, P < .001), and similar DGF (odds ratio: 0.461.032.33, P = .9) and LOS (incidence rate ratio: 0.880.981.10, P = 0.8) compared to younger recipients. The impact of age on mortality (interaction P = .052), DCGF (interaction P = .7), AR interaction P = .2), DGF (interaction P = .9), and LOS (interaction P = .5) were similar in ILDKT and CLDKT recipients. Age alone should not preclude eligibility for ILDKT.

Complications of rabbit anti-thymocyte globulin induction immunosuppression in HIV-infected kidney transplant recipients.

Background: Kidney transplantation in HIV-infected individuals with end-stage kidney disease is associated with improved survival compared to dialysis. Rabbit anti-thymocyte globulin (rATG) induction in HIV-infected kidney transplant recipients has been associated with a lower risk of acute rejection, but data on the rates of de novo malignancy and BK viremia in these patients is lacking. Methods: We performed a single-center retrospective cohort study of adult HIV-infected individuals who underwent kidney transplantation with rATG induction between January 2006 and December 2016. The primary outcome was the development of de novo malignancy. Secondary outcomes included the development of BK viremia, infections requiring hospitalization, HIV progression, biopsy-proven acute rejection, and patient and allograft survival. Results: Twenty-seven HIV-infected individuals with end-stage kidney disease received deceased (n=23) or living (n=4) donor kidney transplants. The cumulative rate of malignancy at five years was 29%, of whom 29% died because of advanced malignancy. BK viremia was detected in six participants (22%), of whom one had biopsy-proven BK virus-associated nephropathy and all of whom cleared the BK viremia. Five-year acute rejection rates, patient survival and death-censored allograft survival were 17%, 85% and 80% respectively. Conclusion: rATG induction in HIV-infected kidney transplant recipients was associated with a low risk of acute rejection, but a potentially higher risk of de novo malignancies and BK viremia in this cohort. Screening strategies to closely monitor for BK virus infection and malignancy post-transplantation may improve outcomes in HIV-infected kidney transplant recipients receiving rATG induction.

Detection of PKD1 and PKD2 Somatic Variants in Autosomal Dominant Polycystic Kidney Cyst Epithelial Cells by Whole-Genome Sequencing.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder characterized by the development of multiple cysts in the kidneys. It is often caused by pathogenic mutations in PKD1 and PKD2 genes that encode polycystin proteins. Although the molecular mechanisms for cystogenesis are not established, concurrent inactivating germline and somatic mutations in PKD1 and PKD2 have been previously observed in renal tubular epithelium (RTE). METHODS: To further investigate the cellular recessive mechanism of cystogenesis in RTE, we conducted whole-genome DNA sequencing analysis to identify germline variants and somatic alterations in RTE of 90 unique kidney cysts obtained during nephrectomy from 24 unrelated participants. RESULTS: Kidney cysts were overall genomically stable, with low burdens of somatic short mutations or large-scale structural alterations. Pathogenic somatic "second hit" alterations disrupting PKD1 or PKD2 were identified in 93% of the cysts. Of these, 77% of cysts acquired short mutations in PKD1 or PKD2 ; specifically, 60% resulted in protein truncations (nonsense, frameshift, or splice site) and 17% caused non-truncating mutations (missense, in-frame insertions, or deletions). Another 18% of cysts acquired somatic chromosomal loss of heterozygosity (LOH) events encompassing PKD1 or PKD2 ranging from 2.6 to 81.3 Mb. 14% of these cysts harbored copy number neutral LOH events, while the other 3% had hemizygous chromosomal deletions. LOH events frequently occurred at chromosomal fragile sites, or in regions comprising chromosome microdeletion diseases/syndromes. Almost all somatic "second hit" alterations occurred at the same germline mutated PKD1/2 gene. CONCLUSIONS: These findings further support a cellular recessive mechanism for cystogenesis in ADPKD primarily caused by inactivating germline and somatic variants of PKD1 or PKD2 genes in kidney cyst epithelium.

Voucher-Based Kidney Donation and Redemption for Future Transplant.

Importance: Policy makers, transplant professionals, and patient organizations agree that there is a need to increase the number of kidney transplants by facilitating living donation. Vouchers for future transplant provide a means of overcoming the chronological incompatibility that occurs when the ideal time for living donation differs from the time at which the intended recipient actually needs a transplant. However, uncertainty remains regarding the actual change in the number of living kidney donors associated with voucher programs and the capability of voucher redemptions to produce timely transplants. Objective: To examine the consequences of voucher-based kidney donation and the capability of voucher redemptions to provide timely kidney allografts. Design, Setting, and Participants: This multicenter cohort study of 79 transplant centers across the US used data from the National Kidney Registry from January 1, 2014, to January 31, 2021, to identify all family vouchers and patterns in downstream kidney-paired donations. The analysis included living kidney donors and recipients participating in the National Kidney Registry family voucher program. Exposures: A voucher was provided to the intended recipient at the time of donation. Vouchers had no cash value and could not be sold, bartered, or transferred to another person. When a voucher was redeemed, a living donation chain was used to return a kidney to the voucher holder. Main Outcomes and Measures: Deidentified demographic and clinical data from each kidney donation were evaluated, including the downstream patterns in kidney-paired donation. Voucher redemptions were separately evaluated and analyzed. Results: Between 2014 and 2021, 250 family voucher-based donations were facilitated. Each donation precipitated a transplant chain with a mean (SD) length of 2.3 (1.6) downstream kidney transplants, facilitating 573 total transplants. Of those, 111 transplants (19.4%) were performed in highly sensitized recipients. Among 250 voucher donors, the median age was 46 years (range, 19-78 years), and 157 donors (62.8%) were female, 241 (96.4%) were White, and 104 (41.6%) had blood type O. Over a 7-year period, the waiting time for those in the National Kidney Registry exchange pool decreased by more than 3 months. Six vouchers were redeemed, and 3 of those redemptions were among individuals with blood type O. The time from voucher redemption to kidney transplant ranged from 36 to 155 days. Conclusions and Relevance: In this study, the family voucher program appeared to mitigate a major disincentive to living kidney donation, namely the reluctance to donate a kidney in the present that could be redeemed in the future if needed. The program facilitated kidney donations that may not otherwise have occurred. All 6 of the redeemed vouchers produced timely kidney transplants, indicating the capability of the voucher program.

COVID-19 outcomes in patients waitlisted for kidney transplantation and kidney transplant recipients.

The COVID-19 pandemic has brought unprecedented challenges to the transplant community. The reduction in transplantation volume during this time is partly due to concerns over potentially increased susceptibility and worsened outcomes of COVID-19 in immunosuppressed recipients. The consequences of COVID-19 on patients waitlisted for kidney transplantation, however, have not previously been characterized. We studied 56 waitlisted patients and 80 kidney transplant recipients diagnosed with COVID-19 between March 13 and May 20, 2020. Despite similar demographics and burden of comorbidities between waitlisted and transplant patients, waitlisted patients were more likely to require hospitalization (82% vs. 65%, P = .03) and were at a higher risk of mortality (34% vs. 16%, P = .02). Intubation was required in one third of hospitalized patients in each group, and portended a very poor prognosis. The vast majority of patients who died were male (84% waitlist, 100% transplant). Multivariate analysis demonstrated waitlist status, age, and male sex were independently associated with mortality. COVID-19 has had a dramatic impact on waitlisted patients, decreasing their opportunities for transplantation and posing significant mortality risk. Understanding the impact of COVID-19 on waitlist patients in comparison to transplant recipients may aid centers in weighing the risks and benefits of transplantation in the setting of ongoing COVID-19.

Center-level Variation in HLA-incompatible Living Donor Kidney Transplantation Outcomes.

BACKGROUND: Desensitization protocols for HLA-incompatible living donor kidney transplantation (ILDKT) vary across centers. The impact of these, as well as other practice variations, on ILDKT outcomes remains unknown. METHODS: We sought to quantify center-level variation in mortality and graft loss following ILDKT using a 25-center cohort of 1358 ILDKT recipients with linkage to Scientific Registry of Transplant Recipients for accurate outcome ascertainment. We used multilevel Cox regression with shared frailty to determine the variation in post-ILDKT outcomes attributable to between-center differences and to identify any center-level characteristics associated with improved post-ILDKT outcomes. RESULTS: After adjusting for patient-level characteristics, only 6 centers (24%) had lower mortality and 1 (4%) had higher mortality than average. Similarly, only 5 centers (20%) had higher graft loss and 2 had lower graft loss than average. Only 4.7% of the differences in mortality (P < 0.01) and 4.4% of the differences in graft loss (P < 0.01) were attributable to between-center variation. These translated to a median hazard ratio of 1.36 for mortality and 1.34 of graft loss for similar candidates at different centers. Post-ILDKT outcomes were not associated with the following center-level characteristics: ILDKT volume and transplanting a higher proportion of highly sensitized, prior transplant, preemptive, or minority candidates. CONCLUSIONS: Unlike most aspects of transplantation in which center-level variation and volume impact outcomes, we did not find substantial evidence for this in ILDKT. Our findings support the continued practice of ILDKT across these diverse centers.

Delayed graft function and acute rejection following HLA-incompatible living donor kidney transplantation.

Incompatible living donor kidney transplant recipients (ILDKTr) have pre-existing donor-specific antibody (DSA) that, despite desensitization, may persist or reappear with resulting consequences, including delayed graft function (DGF) and acute rejection (AR). To quantify the risk of DGF and AR in ILDKT and downstream effects, we compared 1406 ILDKTr to 17 542 compatible LDKT recipients (CLDKTr) using a 25-center cohort with novel SRTR linkage. We characterized DSA strength as positive Luminex, negative flow crossmatch (PLNF); positive flow, negative cytotoxic crossmatch (PFNC); or positive cytotoxic crossmatch (PCC). DGF occurred in 3.1% of CLDKT, 3.5% of PLNF, 5.7% of PFNC, and 7.6% of PCC recipients, which translated to higher DGF for PCC recipients (aOR = 1.03 1.682.72 ). However, the impact of DGF on mortality and DCGF risk was no higher for ILDKT than CLDKT (p interaction > .1). AR developed in 8.4% of CLDKT, 18.2% of PLNF, 21.3% of PFNC, and 21.7% of PCC recipients, which translated to higher AR (aOR PLNF = 1.45 2.093.02 ; PFNC = 1.67 2.403.46 ; PCC = 1.48 2.243.37 ). Although the impact of AR on mortality was no higher for ILDKT than CLDKT (p interaction = .1), its impact on DCGF risk was less consequential for ILDKT (aHR = 1.34 1.621.95 ) than CLDKT (aHR = 1.96 2.292.67 ) (p interaction = .004). Providers should consider these risks during preoperative counseling, and strategies to mitigate them should be considered.

Simultaneous Living Donor Kidney Transplant and Laparoscopic Native Nephrectomy: An Approach to Kidney Transplant Candidates with Suspected Renal-Cell Carcinoma.

Introduction: Kidney transplant candidates are occasionally found during the pre-transplant evaluation to have a suspicious mass in a native kidney. Further work-up and management of such a mass may delay transplantation for several months, which may create logistic barriers to transplant, particularly if there are timing constraints of the donor. In this study, we report our experience with simultaneous living donor kidney transplant and laparoscopic native nephrectomy, where the indication for nephrectomy was a suspicious lesion. Methods: We performed a retrospective review of patients who underwent simultaneous kidney transplant and native nephrectomy using prospectively collected data. We analyzed relevant patient characteristics, surgical details, pathologic results, and long-term follow-up. Results: We identified 16 patients who underwent simultaneous living donor kidney transplantation and laparoscopic native nephrectomy at our institution between 2013 and 2018. Ten (62.5%) patients were found to have renal-cell carcinoma (RCC) on the final pathology. No patients had recurrent RCC, at a median follow-up of 4 years. Conclusion: For patients who are planning to undergo a living donor kidney transplant and are found to have a small mass that is suspicious for RCC, a simultaneous living donor kidney transplant and laparoscopic native nephrectomy is a possible approach in selected patients.

Kidney allograft recipients, immunosuppression, and coronavirus disease-2019: a report of consecutive cases from a New York City transplant center.

BACKGROUND: Kidney graft recipients receiving immunosuppressive therapy may be at heightened risk for coronavirus disease 2019 (Covid-19) and adverse outcomes. It is therefore important to characterize the clinical course and outcome of Covid-19 in this population and identify safe therapeutic strategies. METHODS: We performed a retrospective chart review of 73 adult kidney graft recipients evaluated for Covid-19 from 13 March to 20 April 2020. Primary outcomes included recovery from symptoms, acute kidney injury, graft failure and case fatality rate. RESULTS: Of the 73 patients screened, 54 tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-39 with moderate to severe symptoms requiring hospital admission and 15 with mild symptoms managed in the ambulatory setting. Hospitalized patients were more likely to be male, of Hispanic ethnicity and to have cardiovascular disease. In the hospitalized group, tacrolimus dosage was reduced in 46% of patients and mycophenolate mofetil (MMF) therapy was stopped in 61% of patients. None of the ambulatory patients had tacrolimus reduction or discontinuation of MMF. Azithromycin or doxycycline was prescribed at a similar rate among hospitalized and ambulatory patients (38% versus 40%). Hydroxychloroquine was prescribed in 79% of hospitalized patients. Graft failure requiring hemodialysis occurred in 3 of 39 hospitalized patients (8%) and 7 patients died, resulting in a case fatality rate of 13% among Covid-19-positive patients and 18% among hospitalized Covid-19-positive patients. CONCLUSIONS: Data from our study suggest that a strategy of systematic triage to outpatient or inpatient care, early management of concurrent bacterial infections and judicious adjustment of immunosuppressive drugs rather than cessation is feasible in kidney transplant recipients with Covid-19.

COVID-19 in solid organ transplant recipients: Initial report from the US epicenter.

Solid organ transplant recipients may be at a high risk for SARS-CoV-2 infection and poor associated outcomes. We herein report our initial experience with solid organ transplant recipients with SARS-CoV-2 infection at two centers during the first 3 weeks of the outbreak in New York City. Baseline characteristics, clinical presentation, antiviral and immunosuppressive management were compared between patients with mild/moderate and severe disease (defined as ICU admission, intubation or death). Ninety patients were analyzed with a median age of 57 years. Forty-six were kidney recipients, 17 lung, 13 liver, 9 heart, and 5 dual-organ transplants. The most common presenting symptoms were fever (70%), cough (59%), and dyspnea (43%). Twenty-two (24%) had mild, 41 (46%) moderate, and 27 (30%) severe disease. Among the 68 hospitalized patients, 12% required non-rebreather and 35% required intubation. 91% received hydroxychloroquine, 66% azithromycin, 3% remdesivir, 21% tocilizumab, and 24% bolus steroids. Sixteen patients died (18% overall, 24% of hospitalized, 52% of ICU) and 37 (54%) were discharged. In this initial cohort, transplant recipients with COVID-19 appear to have more severe outcomes, although testing limitations likely led to undercounting of mild/asymptomatic cases. As this outbreak unfolds, COVID-19 has the potential to severely impact solid organ transplant recipients.

Patient and Kidney Allograft Survival with National Kidney Paired Donation.

BACKGROUND AND OBJECTIVES: In the United States, kidney paired donation networks have facilitated an increasing proportion of kidney transplants annually, but transplant outcome differences beyond 5 years between paired donation and other living donor kidney transplant recipients have not been well described. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using registry-linked data, we compared National Kidney Registry (n=2363) recipients to control kidney transplant recipients (n=54,497) (February 2008 to December 2017). We estimated the risk of death-censored graft failure and mortality using inverse probability of treatment weighted Cox regression. The parsimonious model adjusted for recipient factors (age, sex, black, race, body mass index ≥30 kg/m2, diabetes, previous transplant, preemptive transplant, public insurance, hepatitis C, eGFR, antibody depleting induction therapy, year of transplant), donor factors (age, sex, Hispanic ethnicity, body mass index ≥30 kg/m2), and transplant factors (zero HLA mismatch). RESULTS: National Kidney Registry recipients were more likely to be women, black, older, on public insurance, have panel reactive antibodies >80%, spend longer on dialysis, and be previous transplant recipients. National Kidney Registry recipients were followed for a median 3.7 years (interquartile range, 2.1-5.6; maximum 10.9 years). National Kidney Registry recipients had similar graft failure (5% versus 6%; log-rank P=0.2) and mortality (9% versus 10%; log-rank P=0.4) incidence compared with controls during follow-up. After adjustment for donor, recipient, and transplant factors, there no detectable difference in graft failure (adjusted hazard ratio, 0.95; 95% confidence interval, 0.77 to 1.18; P=0.6) or mortality (adjusted hazard ratio, 0.86; 95% confidence interval, 0.70 to 1.07; P=0.2) between National Kidney Registry and control recipients. CONCLUSIONS: Even after transplanting patients with greater risk factors for worse post-transplant outcomes, nationalized paired donation results in equivalent outcomes when compared with control living donor kidney transplant recipients.

Identification of Antibiotic Administration as a Potentially Novel Factor Associated With Tacrolimus Trough Variability in Kidney Transplant Recipients: A Preliminary Study.

Tacrolimus trough variability is an important risk factor for kidney allograft outcomes. Recent evidence suggests that the gut microbiota is associated with tacrolimus dosing requirements and direct metabolism of tacrolimus. We hypothesize that administration of antibiotics, which are known to alter the gut microbiota, is associated with tacrolimus trough variability. METHODS: We conducted a retrospective chart review of subjects who received kidney transplants at our institution from 2012 to 2013 and evaluated subjects who received antibiotics during the first month of transplantation (Abx Group, N = 60) and subjects who did not (No Abx Group, N = 200). We evaluated whether antibiotic administration in the Abx Group had increased tacrolimus trough concentrations and concentration over tacrolimus dosage (C/D) after antibiotic administration. We also evaluated tacrolimus variability as measured by standard deviation (SD) and coefficient of variation between the Abx Group and No Abx Group. RESULTS: In the Abx Group, tacrolimus trough concentration over tacrolimus dosage (C/D) increased 7 and 15 days after antibiotic administration (P = 0.001, P = 0.07, respectively, Wilcoxon signed-rank test). From postoperative day 31-45, the variability in tacrolimus trough levels in the Abx Group as measured by SD and coefficient of variation was significantly higher than the variability in the No Abx Group (P = 0.03, P = 0.02, Wilcoxon rank sum test, respectively). CONCLUSIONS: Our identification of antibiotic administration as a potentially new risk factor for tacrolimus trough variability suggests the need to carefully follow tacrolimus trough levels after antibiotic administration.

Antibiotic prophylaxis for ureteral stent removal after kidney transplantation.

There are no guidelines for antibiotic prophylaxis for ureteral stent removal after kidney transplantation. We reviewed the charts of 277 adult kidney transplant recipients with ureteral stents transplanted at our center between September 2014 and December 2015 and investigated whether antibiotic prophylaxis for stent removal was associated with reduced incidence of urinary tract infections (UTI). We defined UTI as a urine culture ≥104  CFU/mL of bacterial isolates irrespective of symptoms. Primary outcome was the incidence of UTI within four weeks of stent removal. Among the 277 recipients, 199 (72%) were on sulfamethoxazole/trimethoprim (SMZ/TMP) as Pneumocystis jirovecii prophylaxis. At the time of ureteral stent removal, 56 recipients (20%) received additional antibiotic prophylaxis (ABX+) and 221 (80%) did not (ABX-). The difference in the incidence of UTI in the ABX(+) group (16%) and ABX(-) group (19%) was not statistically significant (P = 0.85). Variables independently associated with the development of UTI were recipient age (odds ratio [OR] 1.04, [95% confidence interval 1.01-1.07]) and UTI while stents were in situ (OR 3.9 [2.00-7.62]). Use of SMZ/TMP was protective (OR 0.35 [0.18-0.7]). Our study does not show a statistically significant benefit for additional antibiotic prophylaxis for ureteral stent removal. Antibiotic prophylaxis may be beneficial for recipients not on SMZ/TMP at the time of stent removal.

Somatic Mutations in Renal Cyst Epithelium in Autosomal Dominant Polycystic Kidney Disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a ciliopathy caused by mutations in PKD1 and PKD2 that is characterized by renal tubular epithelial cell proliferation and progressive CKD. Although the molecular mechanisms involved in cystogenesis are not established, concurrent inactivating constitutional and somatic mutations in ADPKD genes in cyst epithelium have been proposed as a cellular recessive mechanism. METHODS: We characterized, by whole-exome sequencing (WES) and long-range PCR techniques, the somatic mutations in PKD1 and PKD2 genes in renal epithelial cells from 83 kidney cysts obtained from nine patients with ADPKD, for whom a constitutional mutation in PKD1 or PKD2 was identified. RESULTS: Complete sequencing data by long-range PCR and WES was available for 63 and 65 cysts, respectively. Private somatic mutations of PKD1 or PKD2 were identified in all patients and in 90% of the cysts analyzed; 90% of these mutations were truncating, splice site, or in-frame variations predicted to be pathogenic mutations. No trans-heterozygous mutations of PKD1 or PKD2 genes were identified. Copy number changes of PKD1 ranging from 151 bp to 28 kb were observed in 12% of the cysts. WES also identified significant mutations in 53 non-PKD1/2 genes, including other ciliopathy genes and cancer-related genes. CONCLUSIONS: These findings support a cellular recessive mechanism for cyst formation in ADPKD caused primarily by inactivating constitutional and somatic mutations of PKD1 or PKD2 in kidney cyst epithelium. The potential interactions of these genes with other ciliopathy- and cancer-related genes to influence ADPKD severity merits further evaluation.

The first 9 years of kidney paired donation through the National Kidney Registry: Characteristics of donors and recipients compared with National Live Donor Transplant Registries.

The practice of kidney paired donation (KPD) is expanding annually, offering the opportunity for live donor kidney transplant to more patients. We sought to identify if voluntary KPD networks such as the National Kidney Registry (NKR) were selecting or attracting a narrower group of donors or recipients compared with national registries. For this purpose, we merged data from the NKR database with the Scientific Registry of Transplant Recipients (SRTR) database, from February 14, 2008, to February 14, 2017, encompassing the first 9 years of the NKR. Compared with all United Network for Organ Sharing (UNOS) live donor transplant patients (49 610), all UNOS living unrelated transplant patients (23 319), and all other KPD transplant patients (4236), the demographic and clinical characteristics of NKR transplant patients (2037) appear similar to contemporary national trends. In particular, among the NKR patients, there were a significantly (P < .001) greater number of retransplants (25.6% vs 11.5%), hyperimmunized recipients (22.7% vs 4.3% were cPRA >80%), female recipients (45.9% vs 37.6%), black recipients (18.2% vs 13%), and those on public insurance (49.7% vs 41.8%) compared with controls. These results support the need for greater sharing and larger pool sizes, perhaps enhanced by the entry of compatible pairs and even chains initiated by deceased donors, to unlock more opportunities for those harder-to-match pairs.

A liver for a kidney: Ethics of trans-organ paired exchange.

Living donation provides important access to organ transplantation, which is the optimal therapy for patients with end-stage liver or kidney failure. Paired exchanges have facilitated thousands of kidney transplants and enable transplantation when the donor and recipient are incompatible. However, frequently willing and otherwise healthy donors have contraindications to the donation of the organ that their recipient needs. Trans-organ paired exchanges would enable a donor associated with a kidney recipient to donate a lobe of liver and a donor associated with a liver recipient to donate a kidney. This article explores some of the ethical concerns that trans-organ exchange might encounter including unbalanced donor risks, the validity of informed consent, and effects on deceased organ donation.

Hospital readmissions following HLA-incompatible live donor kidney transplantation: A multi-center study.

Thirty percent of kidney transplant recipients are readmitted in the first month posttransplantation. Those with donor-specific antibody requiring desensitization and incompatible live donor kidney transplantation (ILDKT) constitute a unique subpopulation that might be at higher readmission risk. Drawing on a 22-center cohort, 379 ILDKTs with Medicare primary insurance were matched to compatible transplant-matched controls and to waitlist-only matched controls on panel reactive antibody, age, blood group, renal replacement time, prior kidney transplantation, race, gender, diabetes, and transplant date/waitlisting date. Readmission risk was determined using multilevel, mixed-effects Poisson regression. In the first month, ILDKTs had a 1.28-fold higher readmission risk than compatible controls (95% confidence interval [CI] 1.13-1.46; P < .001). Risk peaked at 6-12 months (relative risk [RR] 1.67, 95% CI 1.49-1.87; P < .001), attenuating by 24-36 months (RR 1.24, 95% CI 1.10-1.40; P < .001). ILDKTs had a 5.86-fold higher readmission risk (95% CI 4.96-6.92; P < .001) in the first month compared to waitlist-only controls. At 12-24 (RR 0.85, 95% CI 0.77-0.95; P = .002) and 24-36 months (RR 0.74, 95% CI 0.66-0.84; P < .001), ILDKTs had a lower risk than waitlist-only controls. These findings of ILDKTs having a higher readmission risk than compatible controls, but a lower readmission risk after the first year than waitlist-only controls should be considered in regulatory/payment schemas and planning clinical care.

Shipping living donor kidneys and transplant recipient outcomes.

Kidney paired donation (KPD) is an important tool to facilitate living donor kidney transplantation (LDKT). Concerns remain over prolonged cold ischemia times (CIT) associated with shipping kidneys long distances through KPD. We examined the association between CIT and delayed graft function (DGF), allograft survival, and patient survival for 1267 shipped and 205 nonshipped/internal KPD LDKTs facilitated by the National Kidney Registry in the United States from 2008 to 2015, compared to 4800 unrelated, nonshipped, non-KPD LDKTs. Shipped KPD recipients had a median CIT of 9.3 hours (range = 0.25-23.9 hours), compared to 1.0 hour for internal KPD transplants and 0.93 hours for non-KPD LDKTs. Each hour of CIT was associated with a 5% increased odds of DGF (adjusted odds ratio: 1.05, 95% confidence interval [CI], 1.02-1.09, P < .01). However, there was not a significant association between CIT and all-cause graft failure (adjusted hazard ratio [aHR]: 1.01, 95% CI: 0.98-1.04, P = .4), death-censored graft failure ( [aHR]: 1.02, 95% CI, 0.98-1.06, P = .4), or mortality (aHR 1.00, 95% CI, 0.96-1.04, P > .9). This study of KPD-facilitated LDKTs found no evidence that long CIT is a concern for reduced graft or patient survival. Studies with longer follow-up are needed to refine our understanding of the safety of shipping donor kidneys through KPD.

Kidney allograft failure in the steroid-free immunosuppression era: A matched case-control study.

We studied the causes and predictors of death-censored kidney allograft failure among 1670 kidney recipients transplanted at our center in the corticosteroid-free maintenance immunosuppression era. As of January 1, 2012, we identified 137 recipients with allograft failure; 130 of them (cases) were matched 1-1 for recipient age, calendar year of transplant, and donor type with 130 recipients with functioning grafts (controls). Median time to allograft failure was 29 months (interquartile range: 18-51). Physician-validated and biopsy-confirmed categories of allograft failure were as follows: acute rejection (21%), glomerular disease (19%), transplant glomerulopathy (13%), interstitial fibrosis tubular atrophy (10%), and polyomavirus-associated nephropathy (7%). Graft failures were attributed to medical conditions in 21% and remained unresolved in 9%. Donor race, donor age, human leukocyte antigen mismatches, serum creatinine, urinary protein, acute cellular rejection, acute antibody-mediated rejection, BK viremia, and CMV viremia were associated with allograft failure. Independent predictors of allograft failure were acute cellular rejection (odds ratio: 18.31, 95% confidence interval: 5.28-63.45) and urine protein ≥1 g/d within the first year post-transplantation (5.85, 2.37-14.45). Serum creatinine ≤1.5 mg/dL within the first year post-transplantation reduced the odds (0.29, 0.13-0.64) of allograft failure. Our study has identified modifiable risk factors to reduce the burden of allograft failure.