Posttransplantation acute tubular necrosis: risk factors and implications for graft survival

Previous studies aimed at identifying the causes, risk factors, and outcome of kidney transplant recipients with delayed graft function (DGF) have yielded controversial results. We retrospectively analyzed the causes and risk factors for DGF in 263 cadaveric kidney transplantations from November 1988 to March 1997 in one center. Causes of DGF were assessed by postoperative graft evolution and graft biopsy. Univariate and multivariate analysis were used to investigate the risk factors for DGF induced by acute tubular necrosis (ATN). Seventy-six patients (29%) had DGF, which was caused by ATN in 70 patients (92.1%) and acute rejection (AR) in 6 patients (7.9%). Therefore, we focused on risk factors and consequences for ATN-induced DGF. In monofactorial analysis, ATN was significantly associated with greater weight and presence of an atheromatous disease in both donor and recipient. Other risk factors for ATN were older age of donor, recipient American Society of Anesthesiology (ASA) physical status category IV, cold ischemia time (CIT), and transplantation using the right kidney. The multivariate analysis showed that donor and recipient weight, donor age, transplantation using the right kidney, preservation in Eurocollins solution, ASA score, and CIT were associated with ATN. The incidence of rejection and renal function were not different at 3 months or 1 and 5 years. ATN is the main cause of DGF in kidney transplant recipients. ATN is caused by donor and recipient vascular background, grafting the right kidney, and CIT. ATN does not appear to have an adverse effect on long-term kidney function.     

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 = _1.031.68_2.72). 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 = _1.452.09_3.02; PFNC = _1.672.40_3.46; PCC = _1.482.24_3.37). 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 = _1.341.62_1.95) than CLDKT (aHR = _1.962.29_2.67) (p interaction = .004). Providers should consider these risks during preoperative counseling, and strategies to mitigate them should be considered.     

Association of diagnosed obstructive sleep apnea with kidney transplant outcomes

Obstructive sleep apnea (OSA) is common but underdiagnosed among patients with kidney disease. This study examines whether the diagnosis of OSA in kidney transplant recipients (KTR) affected death, death‐censored graft failure (DCGF), and acute rejection (AR). We analyzed the records of KTR who underwent transplant between 2000 and 2015. A total of 4014 kidney transplants were performed during the study period. Of these, 415 (10.3%) had a diagnosis of pretransplant OSA. Pretransplant OSA was associated with a higher risk of death in unadjusted analyses. After adjustment for potential confounders, pretransplant OSA was not associated with risk of death (HR = 1.04, 95% CI: 0.80‐1.36). Similarly, pretransplant OSA was associated with a slightly higher incidence of DCGF or AR but neither associations were significant (HR: 1.23, 95% CI: 0.85‐1.47 for DCGF; HR 1.10, 95% CI: 0.90‐1.36 for AR). A total of 117 (3.3%) were diagnosed with de novo OSA after transplant. Similar to the pretransplant OSA, unadjusted HR for death was significantly higher in the de novo OSA group (HR: 1.48, 95% CI: 1.19‐1.84); however, after adjustment, de novo OSA was not significantly associated with risk of death (HR: 1.15, 95% CI: 0.92‐1.45). Similarly, DCGF and AR rates were not significantly associated with de novo OSA (HR: 1.10, 95% CI: 0.84‐1.44 for DCGF; HR 1.10, 95% CI: 0.90‐1.33 for AR). Our work did not detect significant associations between OSA and risk of death, graft failure, and rejection but the estimates might be underestimated due to underdiagnosis of OSA.     

Delayed kidney graft function in simultaneous pancreas‐kidney transplant recipients is associated with early pancreas allograft failure

Delayed graft function (DGF) is a common complication associated with significant untoward effects in kidney‐alone transplantation. The incidence and outcomes following kidney delayed graft function (K‐DGF) among patients undergoing simultaneous pancreas‐kidney (SPK) transplantation are less certain. We analyzed SPK recipients transplanted at our center between January 1994 and December 2017. A total of 632 recipients fulfilled the selection criteria, including 69 (11%) with K‐DGF and 563 without. The incidence of K‐DGF was significantly higher in recipients of organs from older donors and donation after circulatory death (DCD). The presence of K‐DGF was significantly associated with an increased risk of pancreas graft failure during the first 90 days (n = 9, incidence rate [IR] 2.45/100 person‐months), but not with late pancreas failure (n = 32, IR 0.84/100 person‐months), kidney graft failure, or patient death. Although DCD was associated with K‐DGF, it was not associated with either pancreas (hazard ratio [HR] 0.91, 95% CI 0.58‐1.44, P = .69) or kidney (HR 1.09, 95% CI 0.66‐1.82, P = .74) graft failure after adjustment for potential confounders. We found K‐DGF to be a significant risk factor for pancreas graft failure but not kidney graft failure, with the major risk period being early (<90 days) posttransplant, and the major donor risk factor being older donor age.     

Rate,Factors, and Outcome of Delayed Graft Function After Kidney Transplantation of Deceased Donors

BackgroundDelayed graft function (DGF) is a frequent complication after kidney transplantation affecting long-term outcome.Patients and methodsA total of 525 consecutive recipients (age 54.2 ± 13.4 years, 33% female) of kidneys from deceased donors transplanted between 2005 and 2012 were retrospectively examined. DGF was defined as the need of dialysis within the first week after transplantation.ResultsDGF developed in 21.1% (n = 111). Factors associated with DGF (P ≤ .035, respectively) were recipient body mass index, C-reactive protein of the recipient, residual diuresis, cold ischemia time, donor age, and diuresis in the first hour after transplantation. Median duration of DGF was 16 (2-66) days. Patients after DGF had a significantly lower GFR compared with recipients without DGF either after 3 (32.9 ± 16.5 vs 46.3 ± 18.4 mL/min/1.73 m²) or after 12 months (38.9 ± 19.3 vs 48.6 ± 20.4 mL/min/1.73 m², P < .001, resp.). During DGF, 12.4% developed BANFF II and 18.0% BANFF I rejection, 20.2% had signs of transplant glomerulitis (first biopsy), and 16.2% (n = 18) remained on dialysis.ConclusionDGF affects 1 out of 5 kidney transplants from deceased donors. Minimizing modifiable risk factors, in particular immunologic risk, may ameliorate the incidence and outcome of DGF. The outcome of DGF depends mainly on the diagnosis of any rejection and worsens upon detection of transplant glomerulitis and pronounced interstitial fibrosis and tubular atrophy (IFTA).     

Late graft failure after kidney transplantation as the consequence of late versus early events

Beyond the first posttransplant year, 3% of kidney transplants fail annually. In a prospective, multicenter cohort study, we tested the relative impact of early versus late events on risk of long‐term death‐censored graft failure (DCGF). In grafts surviving at least 90 days, early events (acute rejection [AR] and delayed graft function [DGF] before day 90) were recorded; serum creatinine (Cr) at day 90 was defined as baseline. Thereafter, a 25% rise in serum Cr or new‐onset proteinuria triggered graft biopsy (index biopsy, IBx), allowing comparison of risk of DCGF associated with early events (AR, DGF, baseline serum Cr >2.0 mg/dL) to that associated with later events (IBx). Among 3678 patients followed for 4.7 ± 1.9 years, 753 (20%) had IBx at a median of 15.3 months posttransplant. Early AR (HR = 1.77, P < .001) and elevated Cr at Day 90 (HR = 2.56, P < .0001) were associated with increased risk of DCGF; however, later‐onset dysfunction requiring IBx had far greater impact (HR = 13.8, P < .0001). At 90 days, neither clinical characteristics nor early events distinguished those who subsequently did or did not undergo IBx or suffer DCGF. To improve long‐term kidney allograft survival, management paradigms should promote prompt diagnosis and treatment of both early and later events.     

Factors That Influence Delayed Graft Function in Kidney Transplants: A Single-Center Paired Kidney Analysis

BackgroundThe risk factors associated with delayed graft function (DGF) and its impact in kidney transplant (KTx) outcomes remains controversial; it is possible that donor renal characteristics influence the initial graft function in KTx.ObjectiveEvaluate risk factors associated with DGF and its impact in KTx outcomes.MethodsOne hundred six mate KTx mate recipients performed in a single center were grouped according to the presence or absence of DGF.ResultsDonors were predominantly men (58%); 70% were standard criteria type, with a mean Kidney Donor Profile Index (KDPI) of 62% ± 28%, median age of 42 ± 15 and presenting hospitalization time of 6 ± 5 days. KTx recipients presented an overall DGF rate of 82%, lasting 12 ± 7 days. Pairs presenting DGF were older than pairs without DGF (P = .008), while cold ischemia time (CIT) was significantly shorter in the group without DGF compared to those presenting DGF (P = .003). The KDPI of the KTx pairs was significantly higher in pairs with DGF versus without DGF (P = .04). No statistically significant differences in 1 year allograft and patient survival were observed. Recipient age (odds ratio = 6.3, confidence interval = 1.5–25.8; P = .009) and CIT (odds ratio = 4.6, confidence interval = 1.2–17.7; P = .002) were significantly associated with DGF.ConclusionThis study suggests that recipient age, cold ischemic time, and KDPI are factors associated with DGF. In addition, DGF had no impact on 1-year renal function, allograft, and patient survival. In the transplant conditions of our country, Brazil, CIT seems to represent an important variable to be managed, and the aim should be to reduce this factor as much as possible.     

Incidence,Risk Factors,and Outcomes of Delayed Graft Function in Deceased Donor Kidney Transplantation

ObjectiveDelayed graft function (DGF) is the most significant complication of a cadaveric kidney transplant. We aim to evaluate the predictable risk factors of DGF and its effects on the recipient and graft survival.MethodFrom January 2014 to December 2017, the medical records from 62 patients who received a kidney transplant from a deceased donor were retrospectively reviewed. We classified recipients into 2 groups. The risk factors of DGF associated with donor, recipient, and transplant procedures were analyzed. DGF's effects on the graft survival were examined.ResultsThe incidence rate of DGF was 43.5%. Older ages of donors, marginal donors (n = 15), length of stay in the intensive care unit, and terminal serum creatinine concentrations were observed to be statistically significant compared to recipients without DGF (P < .5). The ratio of serum creatinine concentrations before/after brain death was found to be significant for the groups with DGF (P < .05). Cold ischemia time (CIT) was examined as the most significant risk factor on DGF (P = .001). One-year patient survival rates were 94.5% and 92.3%, and graft survival rates were 92.1% and 87.5% (P = .05), respectively, for the groups with and without DGF.ConclusionOlder ages of donors, occurrence of acute kidney injury, its grade just before harvesting, and long duration of CIT are the most important risk factors for DGF. Brain death management, shortening the time between brain death and harvesting, and also shortening the duration of CIT can decrease the risk of DGF and can increase the graft survival.     

Clinical and Histopathologic Comparative Analysis Between Kidney Transplant Recipients From Expanded-Criteria Donors and Standard-Criteria Donors

Owing to the disparity between the supply of kidney donors and demand, the use of organs from older deceased donors was initiated in recent years. The potentially poor outcome of these grafts is a major concern. This retrospective study compares graft and patient 1-year survivals between recipients from expanded-criteria donors (ECD; n = 30) and standard-criteria donors (SCD; n = 104). Rates of delayed graft function (DGF), acute rejection (AR), and chronic injury in the pre-implantation biopsy were also assessed. Increasing donor age was associated with increased rates of DGF, and DGF correlated with AR. Cold ischemia time >30 hours was associated with worse graft outcomes. Induction with Simulect correlated with better patient survival compared with Timoglobulina. Chronic injury pre-implantation biopsy correlated with worse renal function, but graft survival was similar. Death-censored graft survival at 1 year was 90% and patient survival 82%, and these were similar in ECD and SCD recipients. Selection of transplant candidates for ECD kidneys must be performed with caution. One-year graft survival was similar to that of SCD kidneys, but kidney function was worse during the same period. This may result in poorer graft survival over longer follow-up.     

Retrospective Evaluation of the Effect of Mycophenolate Mofetil Dosage on Survival of Kidney Grafts Based on Biopsy Results

IntroductionPlasma concentration monitoring is commonly used to adjust immunosuppressant dosage in transplant recipients, but adjustment is often based on clinical experience rather than rigorous quantitative indicators.MethodsWe examined the effect of mycophenolate mofetil (MMF) dosage on graft survival by pathologic and immunologic analysis of 88 kidney recipients who were given a postoperative immunosuppressive regimen of tacrolimus (FK506), MMF, and corticosteroids. Patients were given a conventional dosage (≥1.5 g/d; n = 40) or a reduced dosage (n = 48) of MMF owing to postoperative adverse side effects.ResultsThe reduced-dose group included patients given low doses (≤1.0 g/d; n = 27), ultra-low doses (≤0.5 g/d; n = 15), and those who discontinued MMF (n = 6). The dose reduction group had increased acute rejection, chronic rejection, and graft dysfunction, poorer pathologic scores, and increased cell infiltration of graft tissue (CD4, CD8, CD68, and CD138 positivity) and expression of interleukin-2R and HLA-DR. Finally, hazard analysis indicated that patients given low doses and ultra-low doses of MMF had poorer long-term kidney grafts survival (hazard ratios of 1.52 and 1.78, respectively).ConclusionsThese results indicate the importance of using an appropriate dosage of MMF in kidney transplant recipients.     

Risk factors for slow graft function after kidney transplants: a multivariate analysis

BACKGROUND: We previously defined an intermediate group of cadaver kidney transplant recipients who do not have immediate graft function (IGF), but do not have sufficient graft dysfunction to be classified as having delayed graft function (DGF). We showed that this group with slow graft function (SGF) had an increased risk of rejection and inferior long-term results vs. recipients with IGF. The aim of our current study was to determine risk factors for SGF, which have not been well defined (in contrast to risk factors for DGF). METHODS: Between January 1, 1984 and September 30, 1999, we performed 896 adult cadaver kidney transplants at the University of Minnesota. Recipients were analysed in three groups based on initial graft function: IGF [creatinine (Cr) < 3 mg/dL by post-operative day (POD) no. 5], SGF (Cr > 3 mg/dL on POD no. 5, but no need for dialysis), and DGF (need for dialysis in the first week post-transplant). A multivariate analysis looked specifically at risk factors for SGF, as compared with risk factors for DGF. Outcomes with regard to graft survival and acute rejection (AR) rates were determined for the three groups. RESULTS: Of the 896 recipients, 425 had IGF, 238 had SGF, and 233 had DGF. A multivariate analysis of risk factors for SGF showed donor age >50 yr (RR=3.3, p=0.0001) and kidney preservation time >24 h (RR=1.6, p=0.01) to be the most significant risk factors. A multivariate analysis of risk factors for DGF showed similar findings, although high panel-reactive antibodies (PRA) and donor Cr >1.7 mg/dL were also significant risk factors for DGF. Initial function of the graft significantly influenced the subsequent risk of AR: at 12 months post-transplant, the incidence of AR was 28% for those with IGF, 38% for those with SGF, and 44% for those with DGF (p=0.04 for SGF vs. DGF). Initial graft function also significantly influenced graft survival: the 5-yr death-censored graft survival rate was 89% for recipients with IGF, 72% for those with SGF, and 67% for those with DGF (p=0.01 for IGF vs. SGF; p=0.03 for SGF vs. DGF). CONCLUSIONS: SGF represents part of the spectrum of graft injury and post-transplant graft dysfunction. Risk factors for SGF are similar to those seen for DGF. Even mild to moderate graft dysfunction post-transplant can have a negative impact on long-term graft survival.     

Risk factors and outcomes analyses at 36 months of a prospective, randomized, multicenter, trial of daclizumab induction in simultaneous kidney-pancreas transplant recipients

The purpose of this study was to analyze risk factors for acute rejection (AR) and long-term outcomes in simultaneous kidney-pancreas transplant (SKPT) patients enrolled in a prospective, multicenter study of daclizumab (DAC) versus no antibody induction. METHODS: A total of 298 SKPT patients were randomized into three groups and categorized based on an intent to treat analysis, and factors associated with AR and survival were identified using logistic regression and Cox proportional hazards models. RESULTS: There were no differences in patient or allograft survival or rejection rates among the three groups at 36 months follow-up. Delayed (kidney) graft function (DGF) was a risk factor for subsequent kidney AR (odds ratio = 2.79, P = .002). The presence of kidney AR was also a risk factor (hazard ratio [HR] = 3.1, P = .003) for kidney graft loss, whereas risk factors for pancreas graft loss (censored for graft loss within 30 days or death with functioning graft) included pancreas AR (HR = 1.97, P = .012), kidney AR (HR = 1.61, P = .042), CMV serostatus donor +/recipient - (HR = 1.62, P = .026), and HLA-B mismatch (HR = 1.58, P = .01). Kidney graft loss (HR = 5.5, P = .02) was the only predictor of mortality. CONCLUSIONS: At 36 months, no significant differences in outcomes were noted in the three study groups. DGF was the major risk factor for kidney AR, kidney AR was the major risk factor for kidney graft loss, and kidney graft loss was the major determinant of mortality. Prevention of kidney DGF and AR in SKPT recipients may play a pivotal role in optimizing long-term outcomes.     

Elevated Preoperative Recipient Neutrophil-Lymphocyte Ratio Is Associated With Delayed Graft Function Following Kidney Transplantation

Introduction

The neutrophil-lymphocyte ratio (NLR) is an indicator of inflammatory status. We studied the effect of preoperative elevated NLR in the recipient in relation to the risk of developing delayed graft function (DGF) after kidney transplantation.

Methods

We retrospectively analysed the preoperative white blood cell count of renal transplant recipients between 2003 and 2005. An NLR >3.5 was considered elevated. There were 398 kidney transplant recipients of whom 249 received organs from donors after brain death (DBD), 61 from donors after circulatory death (DCD), and 88 from living donors.

Results

One hundred three patients (26%) developed DGF, of which 67 (65%) had NLRs >3.5. Of 295 recipients with primary graft function, only 44 (15%) had elevated NLR. Univariate analysis revealed three factors that significantly influenced graft function: NLR >3.5, cold ischemic time (CIT) >15 hours, and donor type. On multivariate analysis, both donor type (DCD: hazard ratio [HR] = 2.421, confidence interval [CI] = 1.195–4.905, P = .014; LD: HR = 0.289, CI = 0.099–0.846, P = .024) and NLR (HR = 10.673, CI = 6.151–18.518, P < .0001) remained significant.

Conclusions

Elevated recipient preoperative NLR could contribute to increase the risk of developing DGF, which appears to be more pronounced in patients receiving grafts from living donors.     

Effect of delayed graft function on longer-term outcomes after kidney transplantation from donation after circulatory death donors in the United Kingdom: A national cohort study

Kidneys from donation after circulatory death (DCD) donors are utilized variably worldwide, in part due to high rates of delayed graft function (DGF) and putative associations with adverse longer-term outcomes. We aimed to determine whether the presence of DGF and its duration were associated with poor longer-term outcomes after kidney transplantation from DCD donors. Using the UK transplant registry, we identified 4714 kidney-only transplants from controlled DCD donors to adult recipients between 2006 and 2016; 2832 recipients (60·1%) had immediate graft function and 1882 (39·9%) had DGF. Of the 1847 recipients with DGF duration recorded, 926 (50·1%) had DGF < 7 days, 576 (31·2%) had DGF 7–14 days, and 345 (18·7%) had DGF >14 days. After risk adjustment, the presence of DGF was not associated with inferior long-term graft or patient survivals. However, DGF duration of >14 days was associated with an increased risk of death-censored graft failure (hazard ratio 1·7, p = ·001) and recipient death (hazard ratio 1·8, p < ·001) compared to grafts with immediate function. This study suggests that shorter periods of DGF have no adverse influence on graft or patient survival after DCD donor kidney transplantation and that DGF >14 days is a novel early biomarker for significantly worse longer-term outcomes.     

Machine perfusion of donor kidneys may reduce graft rejection

Recent evidence suggests that hypothermic machine perfusion of donor kidneys reduces delayed graft function (DGF). This study addresses the effect of machine perfusion (MP) on allograft rejection in the United States. We assembled a retrospective cohort of patients undergoing kidney‐alone transplants in the UNOS database from June 30, 2004 to May 31, 2017. DGF was defined as dialysis requirement in the first week post‐transplant; graft rejection was defined at 6 months and 1 year. Multivariable logistic regression adjusted for recipient and donor factors evaluated the effect of MP on DGF and graft rejection. Records for 79 300 kidney transplants meeting inclusion criteria were abstracted, 42% of which underwent MP. MP kidneys came from older donors, were more likely to have been obtained following donation after cardiac death, and had longer cold ischemic times. Rates of DGF and rejection were similar between MP and static storage kidneys. Following adjustment, recipients of MP kidneys were less likely to experience rejection at 1 year (OR 0.91 [95% CI 0.86‐0.97] P = .002), but not at 6 months post‐transplantation (OR 0.94 [0.88‐1.02] P = .07). This effect persisted following adjustment for cold ischemic time. This study adds to the accumulating evidence demonstrating improved outcomes following MP of kidneys. We encourage protocolized consideration of MP for kidney grafts.     

Risk factors for and outcomes of delayed graft function in live donor kidney transplantation – a retrospective study

Delayed graft function (DGF) in deceased donor kidney transplantation is associated with worse outcomes. DGF has been less well studied in live donor transplantation. We aimed to examine the risk factors for DGF, and associations between DGF and short‐ and long‐term outcomes in live donor kidney transplant recipients. Using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry, we included live donor kidney transplants performed in Australia and New Zealand over 2004–2015 and excluded pediatric recipients (n = 440), pathological donors (n = 97), grafts that failed in the first week (as a proxy for primary non function; n = 38), and grafts with missing DGF data (n = 46). We used multivariable logistic regression to identify the risk factors for DGF and the association between DGF and rejection at 6 months; Cox proportional hazards models to examine the relationship between DGF and patient and graft survival; and linear regression to examine the association between DGF and eGFR at 1 year. DGF occurred in 77 (2.3%) of 3358 transplants. Risk factors for DGF included right‐sided kidney [odds ratio (OR) 2.00 (95% CI 1.18, 3.40)], donor BMI [OR 1.06 per kg/m² (95% CI 1.01, 1.12)]; increasing time on dialysis and total ischemic time [OR 1.09 per hour (1.00, 1.17)]. DGF was associated with increased risk of rejection at 6 months [OR 2.37 (95% CI 1.41, 3.97)], worse patient survival [HR 2.14 (95% CI 1.21, 3.80)] and graft survival [HR 1.98 (95% CI 1.27, 3.10)], and worse renal function at 1 year [Coefficient ‐9.57 (95% CI ?13.5, ?5.64)]. DGF is uncommon after live donor kidney transplantation, but associated with significantly worse outcomes. The only modifiable risk factors identified were kidney side and total ischemic time.     

Graft and patient outcomes of zero‐human leucocyte‐antigen‐mismatched deceased and live donor kidney transplant recipients

Greater compatibility of human leucocyte antigen (HLA) alleles between kidney donors and recipients may lead to improved graft outcomes. This study aimed to compare the incidence of acute rejection and graft failure in zero‐HLA‐mismatched recipients of living‐related (LD) and deceased donor (DD) kidney transplants. Using data from the Australia and New Zealand Dialysis and Transplant Registry, we compared the risk of any acute rejection and biopsy‐proven acute rejection (BPAR) and graft failure in recipients of zero‐HLA‐mismatched kidneys between LD and DD using logistic and Cox regression models. Of the 931 zero‐HLA‐mismatched recipients transplanted between 1990 and 2012, 19 (2.0%) received kidneys from monozygotic/dizygotic twins (twin), 500 (53.7%) from nontwin LD and 412 (44.3%) from DD. Twin kidney transplant recipients did not experience rejection. Compared to DD transplant recipients, the risk of any acute rejection (adjusted odds ratio 0.52, 95%CI 0.34–0.79, P = 0.002) and overall graft failure (adjusted hazard ratio 0.55, 95%CI 0.41–0.73, P < 0.001) was significantly lower in LD recipients independent of initial immunosuppression, but not for BPAR (adjusted odds ratio 0.52, 95%CI 0.16–1.64, P = 0.263). Zero‐HLA‐mismatched DD kidney transplant recipients have a significantly higher risk of any acute rejection episodes and graft loss compared to zero‐HLA‐mismatched LD kidney transplant recipients. A cautious and careful approach in reducing immunosuppression appears to be warranted in this group of transplant recipients.     

Outpatient Management of Delayed Graft Function Is Associated With Reduced Length of Stay Without an Increase in Adverse Events

Delayed graft function (DGF) is a common and costly complication of kidney transplantation. In July 2011, we established a multidisciplinary DGF clinic managed by nurse practitioners to facilitate early discharge and intensive management of DGF in the outpatient setting. We compared length of stay, 30‐day readmission, acute rejection, and patient/graft survival in 697 consecutive deceased donor kidney transplantations performed between July 2009 and July 2014. Patients were divided into three groups: no DGF (n = 487), DGF before implementation of the DGF clinic (n = 118), and DGF clinic (n = 92). Baseline characteristics including age, gender, panel reactive antibody, retransplantation rates, HLA mismatches, induction, and maintenance immunosuppression were not significantly different between pre‐ and post‐DGF clinic groups. Length of stay was significantly longer in pre‐DGF clinic (10.9 ± 6.2 vs. 6.1 ± 2.1 days, p < 0.001). Thirty‐day readmission (21% vs. 16%), graft loss (7% vs. 20%), and patient death (2% vs. 11%) did not differ significantly between pre‐ and post‐DGF clinic. Patients in the DGF clinic were less likely to develop acute rejection (21% vs. 40%, p = 0.006). Outpatient management of DGF in a specialized clinic is associated with substantially shorter hospitalization and lower incidence of acute rejection without significant difference in 30‐day readmission or patient and graft survival.     

Induction Immunosuppression and Clinical Outcomes in Kidney Transplant Recipients Infected With Human Immunodeficiency Virus

There is an increased risk of acute rejection (AR) in human immunodeficiency virus–positive (HIV+) kidney transplant (KT) recipients. Induction immunosuppression is standard of care for those at high risk of AR; however, use in HIV+ patients is controversial, given fears of increased infection rates. We sought to compare clinical outcomes between HIV+ KT recipients who were treated with (i) anti–thymocyte globulin (ATG), (ii) IL‐2 receptor blocker, and (iii) no induction. We studied 830 HIV+ KT recipients between 2000 and 2014, as captured in the Scientific Registry of Transplant Recipients, and compared rates of delayed graft function (DGF), AR, graft loss and death. Infections and hospitalizations were ascertained by International Classification of Diseases, Ninth Revision codes in a subset of 308 patients with Medicare. Compared with no induction, neither induction agent was associated with an increased risk of infection (weighted hazard ratio [wHR] 0.80, 95% confidence interval [CI] 0.55–1.18). HIV+ recipients who received induction spent fewer days in the hospital (weighted relative risk [wRR] 0.70, 95% CI 0.52–0.95), had lower rates of DGF (wRR 0.66, 95% CI 0.51–0.84), less graft loss (wHR 0.47, 95% CI 0.24–0.89) and a trend toward lower mortality (wHR 0.60, 95% CI 0.24–1.28). Those who received induction with ATG had lower rates of AR (wRR 0.59, 95% CI 0.35–0.99). Induction in HIV+ KT recipients was not associated with increased infections; in fact, those receiving ATG, the most potent agent, had the lowest rates. In light of the high risk of AR in this population, induction therapy should be strongly considered.     

Borderline Changes in Renal Transplantation: Are We Aware of the Real Impact in Graft Survival?

BackgroundBorderline changes suspicious for acute T-cell–mediated rejection (BC) are frequently seen on biopsy specimens, but their clinical significance and clinical management are still controversial. Our goal was to compare clinical outcomes of kidney transplant recipients with biopsy-proven BC vs acute T-cell–mediated rejection (aTCMR) and the influence of treating BC on graft outcomes.MethodsA retrospective cohort study was performed in all kidney transplant recipients with biopsy-proven BC and aTCMR between January 2012 and December 2018, according to Banff 2017 criteria; patients with concomitant antibody-mediated rejection were excluded.ResultsWe included 85 patients, 30 with BC (35.3%) and 55 with aTCMR (64.7%). There was no difference between groups regarding demographics, HLA matching and sensitization, immunosuppression, or time of transplant. Treatment with steroids was started in 15 patients with BC (50%) and in all patients with aTCMR, with 4 of the latter additionally receiving thymoglobulin (7.2%). At 1 year post biopsy, overall graft survival was 71%, and despite presenting better estimated glomerular filtration rate (eGFR) at biopsy (33.3 ± 23.4 vs 19.9 ± 13.2 mL/min/1.73 m², P = .008), patients in the BC group presented the same graft survival as the aTCMR group according to Kaplan-Meyer survival curves. When analyzing the BC group (n = 30) and comparing the patients who were treated (n = 15) vs a conservative approach (n = 15), graft survival at 1 year was 87% for treated patients and 73% for nontreated patients (P = .651), with no difference in eGFR for patients with functioning graft. However, at longer follow-up, survival curves showed a trend for better graft survival in treated patients (70.2 ± 9.2 vs 38.4 ± 8.4 months, P = .087).ConclusionOur study showed that patients with BC did not present better graft survival or graft function at 1 year after biopsy or at follow-up compared with the aTCMR group, despite better eGFR at diagnosis. We found a trend for better graft survival in patients with BC treated with steroids compared with a conservative approach. These results reinforce the importance of borderline changes in graft outcomes and that the decision to treat can influence long-term outcomes.