Predictors and outcomes of delayed graft function after living‐donor kidney transplantation

Delayed graft function (DGF) following deceased donor kidney transplantation is associated with inferior outcomes. Delayed graft function following living‐donor kidney transplantation is less common, but its impact on graft survival unknown. We therefore sought to determine risk factors for DGF following living‐donor kidney transplantation and DGF's effect on living‐donor kidney graft survival. We analyzed living‐donor kidney transplants performed between 2000 and 2014 in the UNOS dataset. A total of 64 024 living‐donor kidney transplant recipients were identified, 3.6% developed DGF. Cold ischemic time, human leukocyte antigen mismatch, donor age, panel reactive antibody, recipient diabetes, donor and recipient body mass index, recipient race and gender, right nephrectomy, open nephrectomy, dialysis status, ABO incompatibility, and previous transplants were independent predictors of DGF in living‐donor kidney transplants. Five‐year graft survival among living‐donor kidney transplant recipients with DGF was significantly lower compared with graft survival in those without DGF (65% and 85%, respectively, P < 0.001). DGF more than doubled the risk of subsequent graft failure (hazard ratio = 2.3, 95% confidence interval: 2.1–2.6; P < 0.001). DGF after living‐donor kidney transplantation is associated with inferior allograft outcomes. Minimizing modifiable risk factors may improve outcomes in living‐donor kidney transplantation.     

Mitochondrial membrane potential and delayed graft function following kidney transplantation

Delayed graft function (DGF) complicates 20%‐40% of deceased‐donor kidney transplants and is associated with increased length of stay and subsequent allograft failure. Accurate prediction of DGF risk for a particular allograft could influence organ allocation, patient counseling, and postoperative planning. Mitochondrial dysfunction, a reported surrogate of tissue health in ischemia‐perfusion injury, might also be a surrogate for tissue health after organ transplantation. To understand the potential of mitochondrial membrane potential (MMP) in clinical decision‐making, we analyzed whether lower MMP, a measure of mitochondrial dysfunction, was associated with DGF. In a prospective, single‐center proof‐of‐concept study, we measured pretransplant MMP in 28 deceased donor kidneys and analyzed the association between MMP and DGF. We used hybrid registry‐augmented regression to adjust for donor and recipient characteristics, minimizing overfitting by leveraging Scientific Registry of Transplant Recipients data. The range of MMP levels was 964‐28 333 units. Low‐MMP kidneys (MMP<4000) were more likely from female donors (75% vs 10%, P = .002) and donation after cardiac death donors (75% vs 12%, P = .004). For every 10% decrease in MMP levels, there were 38% higher odds of DGF (adjusted odds ratio = _1.081.38_1.78, P = .01). In summary, MMP might be a promising pretransplant surrogate for tissue health in kidney transplantation and, after further validation, could improve clinical decision‐making through its independent association with DGF.     

Impact of the kidney allocation system on young pediatric recipients

The kidney allocation system (KAS) altered pediatric candidate prioritization. We determined KAS's impact on pediatric kidney recipients by examining delayed graft function (DGF) rates from 2010 to 2016. A propensity score‐matched pediatric recipients pre‐ and post‐KAS. A semiparametric decomposition analysis estimated the contributions of KAS‐related changes in donor characteristics and dialysis time on DGF rate. The unadjusted odds of DGF were 69% higher post‐KAS for young (<10 years at listing) recipients (N = 1153, P = .02) but were not significantly increased for older pediatric (10‐17 years at listing) recipients (N = 2624, P = .48). Post‐KAS, young recipients received significantly fewer pediatric (<18 years) donor kidneys (21% vs 32%, P < .01) and had longer median pretransplant dialysis time (603 vs 435 days, P < .01). After propensity score matching, post‐KAS status increased the odds of DGF in young recipients 71% (OR 1.71, 95% CI 1.01‐2.46). In decomposition analysis, 24% of the higher DGF rate post‐KAS was attributable to donor characteristics and 19% to increased recipient dialysis time. In a confirmatory survival analysis, DGF was associated with a 2.2 times higher risk of graft failure (aHR2.28, 95% CI 1.46‐3.54). In conclusion, KAS may lead to worse graft survival outcomes in children. Allocation changes should be considered.     

Dynamics of early post‐operative plasma ddcfDNA levels in kidney transplantation: a single‐center pilot study

Donor‐derived cell‐free DNA (ddcfDNA) is reported to be a promising noninvasive biomarker for acute rejection in organ transplant. However, studies on monitoring ddcfDNA dynamics during the early periods after organ transplantation are scarce. Our study assessed the dynamic variation in ddcfDNA in early period with various types and status of kidney transplantation. Target region capture sequencing used identifies ddcfDNA level in 21 kidney transplant recipients. Median ddcfDNA level was 20.69% at the initial time post‐transplant, and decreased to 5.22% on the first day and stayed at the stable level after the second day. The ddcfDNA level in DCD (deceased donors) group (44.99%) was significantly higher than that in LDRT (living donor) group (10.24%) at initial time, P < 0.01. DdcfDNA level in DGF (delayed graft function) recipients was lower (23.96%) than that in non‐DGF (47.74%) at the initial time, P = 0.89 (19.34% in DGF and 4.46% in non‐DGF on the first day, P = 0.17). DdcfDNA level at initial time significantly correlated with serum creatinine (r² = 0.219, P = 0.032) and warm ischemia time (r² = 0.204, P = 0.040). Plasma ddcfDNA level decreased rapidly follow an L‐shaped curve post‐transplant, and level in DGF declined slower than non‐DGF. The rebound of ddcfDNA level may indicate the occurrence of acute rejection.     

Impact of donor age on long‐term outcomes after delayed graft function: 10‐year follow‐up

Delayed graft function (DGF) has a negative impact on graft survival in donation after brain death (DBD) but not for donation after cardiac death (DCD) kidneys. However, older donor age is associated with graft loss in DCD transplants. We sought to examine the interaction between donor age and DGF in DBD kidneys. This is a single‐center, retrospective review of 657 consecutive DBD recipients transplanted between 1990 and 2005. We stratified the cohort by decades of donor age and studied the association between DGF and graft failure using Cox models. The risk of graft loss associated with DGF was not significantly increased for donor age below 60 years (adjusted hazard ratio [aHR] 1.12, 1.51, and 0.90, respectively, for age <40, 41–50 and 51–60 years) but significantly increased after 60 years (aHR 2.67; P = 0.019). Analysis of death‐censored graft failure yielded similar results for donor age below 60 years and showed a substantially increased risk with donors above 60 years (aHR 6.98, P = 0.002). This analysis reveals an unexpectedly high impact of older donor age on the association between DGF and renal transplant outcomes. Further research is needed to determine the best use of kidneys from donors above 60 years old, where DGF is expected.     

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.     

DCD donor hemodynamics as predictor of outcome after kidney transplantation

Insufficient hemodynamics during agonal phase—ie, the period between withdrawal of life‐sustaining treatment and circulatory arrest—in Maastricht category III circulatory‐death donors (DCD) potentially exacerbate ischemia/reperfusion injury. We included 409 Dutch adult recipients of DCD donor kidneys transplanted between 2006 and 2014. Peripheral oxygen saturation (SpO2‐with pulse oximetry at the fingertip) and systolic blood pressure (SBP‐with arterial catheter) were measured during agonal phase, and were dichotomized into minutes of SpO2 > 60% or SpO2 < 60%, and minutes of SBP > 80 mmHg or SBP < 80 mmHg. Outcome measures were and primary non‐function (PNF), delayed graft function (DGF), and three‐year graft survival. Primary non‐function (PNF) rate was 6.6%, delayed graft function (DGF) rate was 67%, and graft survival at three years was 76%. Longer periods of agonal phase (median 16 min [IQR 11‐23]) contributed significantly to an increased risk of DGF (P = .012), but not to PNF (P = .071) and graft failure (P = .528). Multiple logistic regression analysis showed that an increase from 7 to 20 minutes in period of SBP < 80 mmHg was associated with 2.19 times the odds (95% CI 1.08‐4.46, P = .030) for DGF. In conclusion, duration of agonal phase is associated with early transplant outcome. SBP < 80 mmHg during agonal phase shows a better discrimination for transplant outcome than SpO2 < 60% does.     

Kidney transplant from uncontrolled donation after circulatory death donors maintained by nECMO has long‐term outcomes comparable to standard criteria donation after brain death

Uncontrolled donation after circulatory death (uDCD) increases organ availability for kidney transplant (KT) with short‐term outcomes similar to those obtained from donation after brain death (DBD) donors. However, heterogeneous results in the long term have been reported. We compared 10‐year outcomes between 237 KT recipients from uDCD donors maintained by normothermic extracorporeal membrane oxygenation (nECMO) and 237 patients undergoing KT from standard criteria DBD donors during the same period at our institution. We further analyzed risk factors for death‐censored graft survival in the uDCD group. Delayed graft function (DGF) was more common in the uDCD group (73.4% vs 46.4%; P < .01), although glomerular filtration rates at the end of follow‐up were similar in the 2 groups. uDCD and DBD groups had similar rates for 10‐year death‐censored graft (82.1% vs 80.4%; P = .623) and recipient survival (86.2% vs 87.6%; P = .454). Donor age >50 years was associated with graft loss in the uDCD group (hazard ratio: 1.91; P = .058), whereas the occurrence of DGF showed no significant effect. uDCD KT under nECMO support resulted in similar graft function and long‐term outcomes compared with KT from standard criteria DBD donors. Increased donor age could negatively affect graft survival after uDCD donation.     

Organ donor management and delayed graft function in kidney transplant recipients: A multicenter retrospective cohort study

Meeting donor management goals (DMGs) has been reported to decrease the incidence of delayed graft function (DGF) after kidney transplant, but whether this relationship is independent of cold machine perfusion is unclear. We aimed to determine whether meeting DMGs is associated with a reduced incidence of DGF, independent of the use of machine perfusion. We collected data on consecutive brain‐dead donors and their KT recipients (KTRs) between June 2013 and December 2016 in 5 adult transplant centers. We evaluated whether DMGs were met at donor neurologic death (DND) and later time points. We defined a priori meeting optimal DMG as achieving ≥7 DMGs. Generalized estimating equations were used to predict DGF. Among 122 donors, 34% were extended‐criteria donors (ECDs). The number of DMGs met increased over time (5.6 ± 1.4 at DND and 6.1 ± 1.3 at organ procurement [P < .001]). DGF occurred in 23% of 214 KTRs, and 55% received organs placed on machine perfusion. In multivariate analysis, ECD (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.13‐4.45), use of machine perfusion (OR 0.45, 95% CI 0.22‐0.94), and optimal DMG at DND (OR 0.39, 95% CI 0.16‐0.99) were associated with DGF. Early achievement of DMGs was associated with a reduced risk of the development of DGF, independent of the use of machine perfusion.     

High incidence of delayed graft function in HIV‐infected kidney transplant recipients

Kidney transplantation (KT) outcomes in human immunodeficiency virus (HIV)‐infected recipients are under continuous research. High incidence of early post‐transplant complications such as acute rejection has been observed. A multicenter study including HIV‐infected patients who underwent KT in Spain, from 2001 to 2011, was performed. The study population included 108 recipients, 36 HIV‐infected, and 72 matched HIV‐negative KT recipients. HIV‐infected recipients developed more delayed graft function (DGF) (52% vs. 21%, P < 0.001). One‐ and 3‐year graft survival was 91.6% and 86.2% in HIV‐infected patients, and 97.1% and 94.7% in HIV‐negative patients (P = 0.052). In two‐variate Cox analysis, HIV infection was not a predictor of graft loss after adjusting for time on dialysis, acute rejection, and DGF. Multivariate analysis for DGF revealed HIV‐positive status as independent risk factor. We analyzed the evolution of immunosuppressive and antiretroviral therapy (ART). In HIV‐infected patients tacrolimus trough levels were very high in the first week and significantly lower in the second week post‐transplant (P = 0.042). Post‐transplant ART was significantly changed: protease inhibitors use decreased (P = 0.034) and integrase inhibitor use increased (P < 0.001). DGF is another frequent early complication in HIV‐infected recipients that can affect graft survival. Strategies to prevent DGF and antiretroviral regimes with less drug interactions could improve outcomes.     

Duration of delayed graft function and outcomes after kidney transplantation from controlled donation after circulatory death donors: a retrospective study

The impact of the duration of delayed graft function (DGF) on graft survival is poorly characterized in controlled donation after circulatory death (DCD) donor kidney transplantation. A retrospective analysis was performed on 225 DCD donor kidney transplants between 2011 and 2016. When patients with primary nonfunction were excluded (n = 9), 141 recipients (65%) had DGF, with median (IQR) duration of dialysis dependency of 6 (2–11.75) days. Longer duration of dialysis dependency was associated with lower estimated glomerular filtration rate at 1 year, and a higher rate of acute rejection. On Kaplan–Meier analysis, the presence of DGF was associated with lower graft survival (log‐rank test P = 0.034), though duration of DGF was not (P = 0.723). However, multivariable Cox regression analysis found that only acute rejection was independently associated with lower graft survival [HR (95% CI) 4.302 (1.617–11.450); P = 0.003], whereas the presence of DGF and DGF duration were not. In controlled DCD kidney transplantation, DGF duration itself may not be independently associated with graft survival; rather, it may be that acute rejection associated with prolonged DGF is the poor prognostic factor.     

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

Background

A high incidence of delayed graft function (DGF) after deceased donor kidney transplantation occurs in Brazil. The reasons for such have not been adequately studied.

Methods

We performed a retrospective cohort study of 346 kidney transplant recipients from deceased donors. DGF risk factors related to the recipient, donor, and transplantation surgery were analyzed and correlated with graft outcomes. A logistic regression analysis was used to identify independent risk factors and patient and graft survival were assessed using Kaplan-Meier curves.

Results

The incidence of DGF was 70.8% (245 cases). Our final model of multivariate analysis showed that DGF is associated (P < .05) with donor final serum creatinine (relative risk [RR], 1.84; 95% confidence interval [CI], 1.26–2.70), donor age (RR, 1.02 [1.0–1.033]), receiving a kidney from national offer (RR, 2.44 [1.06–5.59]), and need for antibody induction (RR, 2.87 [1.33–6.18]). Outcomes that were associated with DGF were longer length of hospital stay (32.5 ± 20.5 vs 18.8 ± 16.3 days; P = .01), higher incidence of acute rejection (37.8 vs 12.9%; P < .01), worse graft survival at 1 year (83.5% vs 93.9%; P < .01), and higher levels of serum creatinine at 3, 6, and 12 months (P < .05). There was no difference in patient survival and the occurrence of acute rejection did not influence the survival of patients or grafts.

Conclusion

DGF was associated with higher donor final serum creatinine, donor age, receiving a kidney from the national supply, and need for antibody induction. Most importantly, DGF was associated with worse outcomes.     

Effects of expanded allocation programmes and organ and recipient quality metrics on transplant‐related costs in kidney transplantation – an institutional analysis

Expansions of donor pools have a controversial impact on healthcare expenditures. The aim of this study was to investigate the emerging costs of expanded criteria donor (ECD) kidney transplantations (KT) and to identify independent risk factors for increased transplant‐related costs. We present a retrospective explorative analysis of hospital costs and reimbursements of KTs performed between 2012 and 2016 in a German university hospital. A total of 174 KTs were examined, including 92 (52.9%) ECD organ transplantations. The ECD group comprised 43 (24.7%) ‘old‐for‐old’ transplantations. Median healthcare costs were 19 570€ (IQR 18 735–27 405€) in the standard criteria donor (SCD) group versus 25 478€ (IQR 19 957–29 634€) in the ECD group (+30%; P = 0.076). ‘Old‐for‐old’ transplantations showed the highest healthcare expenditures [26 702€ (19 570–33 940€)]. Irrespective of the allocation group, transplant‐related costs increased significantly in obese (+6221€; P = 0.009) and elderly recipients (+6717€; P = 0.019), in warm ischaemia time exceeding 30 min (+3212€; P = 0.009) and in kidneys with DGF or surgical complications (+8976€ and +10 624€; both P < 0.001). Transplantation of ECD organs is associated with incremental costs, especially in elderly and obese recipients. A critical patient selection, treatment of obesity before KT and keeping warm ischaemia times short seem to be crucial, in order to achieve a cost‐effective KT regardless of the allocation group.     

Predictive Characteristics of Delayed Graft Function After Expanded and Standard Criteria Donor Kidney Transplantations

Delayed graft function (DGF) represents one of the most common complications after kidney transplantation. The increased use of expanded criteria donors (ECD) is related to a greater risk for DGF. The objective of our study was to analyze the incidence of DGF among ECD versus standard criteria donors (SCD). Among 121 cases we obtained 2 groups: group A (SCD; n = 75) and group B (ECD; n = 46). Group B was composed of older donors (P < .0001), with an increased incidence of diabetes mellitus (DM; P < .0001), arterial hypertension (AH; P < .0001), cerebrovascular accidents (P = .013), and lower creatinine clearances (CrCl; P = .008). Recipient age was significantly lower among group A (P < .0001), with an increased incidence of donor hypotensive episodes (P = .016). The global incidence of DGF was 40 patients (33%), who were mainly in group B (P = .004). Analyzing the entire population, donor age ≥ 60 years (P = .005), CrCl < 40 mL/min (P = .025), donor history of DM (P = .026) and AH (P = .017), and cold ischemia time > 15 hours (P < .0001) were parameters related to increased incidences of DGF. A biopsy score of 3 was not significantly associated with DGF. The results of our study underlined the increased risk for DGF related to the use of ECD. Donor age ≥ 60 years and cold ischemia time > 15 hours showed strong associations with this complication.     

Negative impact of prolonged cold storage time before machine perfusion preservation in donation after circulatory death kidney transplantation

Kidney grafts are often preserved initially in static cold storage (CS) and subsequently on hypothermic machine perfusion (MP). However, the impact of CS/MP time on transplant outcome remains unclear. We evaluated the effect of prolonged CS/MP time in a single‐center retrospective cohort of 59 donation after circulatory death (DCD) and 177 matched donation after brain death (DBD) kidney‐alone transplant recipients. With mean overall CS/MP times of 6.0 h/30.0 h, overall incidence of delayed graft function (DGF) was higher in DCD transplants (30.5%) than DBD transplants (7.3%, P < 0.0001). In logistic regression, DCD recipient (P < 0.0001), longer CS time (P = 0.0002), male recipient (P = 0.02), and longer MP time (P = 0.08) were associated with higher DGF incidence. In evaluating the joint effects of donor type (DBD vs. DCD), CS time (<6 vs. ≥6 h), and MP time (<36 vs. ≥36 h) on DGF incidence, one clearly sees an unfavorable effect of MP time ≥36 h (P = 0.003) across each donor type and CS time stratum, whereas the unfavorable effect of CS time ≥6 h (P = 0.01) is primarily seen among DCD recipients. Prolonged cold ischemia time had no unfavorable effect on renal function or graft survival at 12mo post‐transplant. Long CS/MP time detrimentally affects early DCD/DBD kidney transplant outcome when grafts were mainly preserved by MP; prolonged CS time before MP has a particularly negative impact in DCD kidney transplantation.     

Outcomes of donation after circulatory death kidneys undergoing hypothermic machine perfusion following static cold storage: A UK population‐based cohort study

Evidence is currently lacking regarding the outcomes of kidneys undergoing hypothermic machine perfusion (HMP) in patients in the United Kingdom. Using the National Health Service Blood and Transplant database, the authors compared outcomes for recipients of single‐organ donation after circulatory death (DCD) kidneys preserved with HMP with those preserved using only static cold storage (SCS). Between 2007 and 2015, HMP was used in 19.1% (864/4,529) of kidneys. Rates of delayed graft function (DGF) were significantly lower in organs preserved with HMP than for organs preserved with SCS (34.2% vs 42.0%, P < .001), despite a slightly longer cold ischemic time (median: 14.8 vs 14.1 hours, P < .001). Multivariable analysis found the effect of preservation modality to remain significant, with HMP organs having a significantly lower rate of DGF (odds ratio 0.65, 95% confidence interval 0.53‐0.80, P < .001) and significantly shorter times to DGF resolution (average: 6.1 vs 7.4 days, P = .003) than SCS organs. The patient (P = .313) and graft (P = .263) survival rates were similar in the 2 preservation groups. HMP was associated with a marginal functional benefit in 1‐year creatinine values (P = .044), with adjusted averages of 1.36 mg/dL (HMP) versus 1.40 mg/dL (SCS). This study supports the use of HMP and aids decision‐making over its instigation, which may improve short‐term patient outcomes.     

Outcomes of kidney transplant from deceased donors with acute kidney injury and prolonged cold ischemia time – a retrospective cohort study

While deceased donor renal transplants (DDRT) from donors with either acute kidney injury (AKI) or long cold ischemia time (CIT) are associated with increased risk of delayed graft function (DGF), recipients of these kidneys have good patient and allograft survival. There are limited data on whether kidneys with both AKI and long CIT have outcomes similar to kidneys with only one of these insults. Using data from the Scientific Registry of Transplant Recipients, we analyzed transplant outcomes in patients (2005–2015) receiving kidneys with AKI (terminal creatinine ≥2.0 mg/dl) and CIT 24–30 h (n = 1289), 30–36 h (n = 734), and >36 h (n = 614), using kidneys with AKI and CIT <24 h (n = 5434) as a reference. DGF was more common with increasing CIT up to 36 h, then decreased slightly (41.2% vs. 46.8% vs. 52.5% vs. 50.2%, P < 0.001). Death‐censored graft survival (DCGS) at 3 years was better with CIT <24 h compared with other groups (92.5% vs. 90.8% vs. 92% vs. 89.2%, P = 0.018). On multivariable analysis, donor creatinine was predictive of DCGS, whereas only CIT >36 h was predictive of DCGS (aHR 1.27, P = 0.03). Recipients transplanted with kidneys with both AKI and long CIT have excellent intermediate‐term outcomes.     

Associations of Deceased Donor Kidney Injury With Kidney Discard and Function After Transplantation

Deceased donor kidneys with acute kidney injury (AKI) are often discarded due to fear of poor outcomes. We performed a multicenter study to determine associations of AKI (increasing admission‐to‐terminal serum creatinine by AKI Network stages) with kidney discard, delayed graft function (DGF) and 6‐month estimated glomerular filtration rate (eGFR). In 1632 donors, kidney discard risk increased for AKI stages 1, 2 and 3 (compared to no AKI) with adjusted relative risks of 1.28 (1.08–1.52), 1.82 (1.45–2.30) and 2.74 (2.0–3.75), respectively. Adjusted relative risk for DGF also increased by donor AKI stage: 1.27 (1.09–1.49), 1.70 (1.37–2.12) and 2.25 (1.74–2.91), respectively. Six‐month eGFR, however, was similar across AKI categories but was lower for recipients with DGF (48 [interquartile range: 31–61] vs. 58 [45–75] ml/min/1.73m² for no DGF, p < 0.001). There was significant favorable interaction between donor AKI and DGF such that 6‐month eGFR was progressively better for DGF kidneys with increasing donor AKI (46 [29–60], 49 [32–64], 52 [36–59] and 58 [39–71] ml/min/1.73m² for no AKI, stage 1, 2 and 3, respectively; interaction p = 0.05). Donor AKI is associated with kidney discard and DGF, but given acceptable 6‐month allograft function, clinicians should consider cautious expansion into this donor pool.     

Nighttime procedures are not associated with adverse outcomes in kidney transplantation

Surgeries performed during the night are associated with higher complication rates. The aim of this study was to determine the impact of nighttime surgery on the outcome after kidney transplantation. In all, 873 deceased donor kidney transplants were retrospectively analyzed and grouped according to the time of surgery: daytime (8 am to 8 pm , n = 610) versus nighttime (8 pm to 8 am , n = 263). Statistical analysis compared patient/graft survival, rate of delayed graft function (DGF), acute rejection rate, and surgical complications. One and 5‐year patient and graft survival did not differ between daytime and nighttime transplants. DGF occurred in 31.1% of daytime compared to 37.6% of nighttime procedures (P = 0.06). Acute allograft rejection was observed in 22.6% of daytime compared to 18.3% in nighttime graft recipients (P = 0.15). Nighttime procedures were associated with 22.4% complications compared to 22.1% in daytime procedures (P = 0.92). Most importantly, if transplantations were postponed until the next morning, cold ischemia time (CIT) would have increased from 16.6 h to 24.6 h (P < 0.0001) which would have resulted in decreased long‐term survival (P < 0.02). Nighttime kidney transplants are neither associated with a higher surgical complication rate nor worse 5‐year outcomes than daytime procedures, thus are justified to keep CIT short.     

Glucocorticoid‐induced tumour necrosis factor receptor expression: a potential molecular link between steroid intake and complicated diverticulitis?

Aim Immunosuppression and steroid medication have been identified as risk factors for complicated sigmoid diverticulitis. The underlying molecular mechanisms have not yet been elucidated. We hypothesized that glucocorticoid‐induced tumour necrosis factor receptor (GITR) and matrix metalloproteinase‐9 (MMP‐9) might play a role. Method GITR and MMP‐9 were analysed at protein [immunohistochemistry/immunofluorescence (IF)] and messenger RNA level (real‐time polymerase chain reaction) in surgical specimens with complicated and non‐complicated diverticulitis (n = 101). IF double staining and regression analysis were performed for both markers. GITR expression was correlated with clinical data and its usefulness as a diagnostic test was investigated. Results High GITR expression (≥ 41%) was observed in the inflammatory infiltrate in complicated diverticulitis, in contrast to non‐complicated diverticulitis where GITR expression was low (P < 0.001). High GITR expression was significantly associated with steroid use and pulmonary diseases (both P < 0.001). MMP‐9 expression correlated with GITR expression (R² = 0.7268, P < 0.0001, r = 0.85) as demonstrated with IF double‐staining experiments. Co‐labelling of GITR with CD68, but not CD15, suggested that GITR‐expressing cells in diverticulitis are macrophages. GITR expression was superior to C‐reactive protein (CRP), white cell count and temperature in distinguishing complicated and non‐complicated diverticulitis. Conclusions Our results suggest that GITR expression in inflammatory cells might potentially indicate a molecular link between steroid use and complicated forms of acute sigmoid diverticulitis. Increased MMP‐9 expression by GITR signalling might explain the morphological changes in the colonic wall of perforated and phlegmonous diverticulitis. Analysis of soluble GITR might be a promising strategy for future research.