Detrimental effect of acute renal failure on the survival of renal allografts: influence of total ischaemia time and anastomosis time

Renal Transplantation in Patients Undergoing Chronic Peritoneal Dialysis

Objective

To review the outcome of renal transplantation in a group of patients treated with chronic peritoneal dialysis and to compare the results with those of a matched population on hemodialysis.

Design

Retrospective study.

Setting

Tertiary, institutional hospital, administering to a population of two million, with 100 patients on peritoneal dialysis. Six hundred and sixty renal transplantations were performed by the end of 1993.

Patients

Fifty-six patients on chronic peritoneal dialysis who received 58 cadaveric renal allografts were compared to 58 patients on hemodialysis who received a graft from the same donor (n = 39), or the transplant next to the one performed to the corresponding patient on peritoneal dialysis (n = 19).

Results

Patients on peritoneal dialysis showed a lower rate of delayed graft function (24.1 vs 50%, p < 0.05) and a similar incidence of acute rejection than patients on hemodialysis. Also, peritoneal dialysis patients received less supplementary immunosuppression, suffered a lower incidence of late infections (0.93 vs 0.58 episodes/patient), and had a similar incidence of dialysis-related complications (0.25 vs 0.20 episodes/patient).

Conclusions

Patients on peritoneal dialysis do well after renal transplantation. The incidence of some complications, particularly delayed graft function, is lower than in patients on hemodialysis, while the incidence of dialysis-associated complications is similar in both groups.

Increased immunogenicity is an integral part of the heat shock response following renal ischemia

Renal ischemia increases tubular immunogenicity predisposing to increased risk of kidney allograft rejection. Ischemia-reperfusion not only disrupts cellular homeostasis but also induces the cytoprotective heat shock response that also plays a major role in cellular immune and defense processes. This study therefore tested the hypothesis that upregulation of renal tubular immunogenicity is an integral part of the heat shock response after renal ischemia. Expressions of 70 kDa heat shock protein (Hsp70), major histocompatibility complex (MHC) class II, and intercellular adhesion molecule-1 (ICAM-1) were assessed in normal rat kidney (NRK) cells following ATP depletion (antimycin A for 3 h) and heat (42°C for 24 h). In vitro, transient Hsp70 transfection and heat shock factor-1 (HSF-1) transcription factor decoy treatment were performed. In vivo, ischemic renal cortex was investigated in Sprague-Dawley rats following unilateral renal artery clamping for 45 min and 24 h recovery. Upregulation of Hsp70 was closely and significantly correlated with upregulation of MHC class II and/or ICAM-1 following ATP depletion and heat injury. Bioinformatics analysis searching the TRANSFAC database predicted HSF-1 binding sites in these genes. HSF-1 decoy significantly reduced the expression of immunogenicity markers in stressed NRK cells. In the in vivo rat model of renal ischemia, concordant upregulation of MHC class II molecules and Hsp70 suggests biological relevance of this link. The results demonstrate that upregulation of renal tubular immunogenicity is an integral part of the heat shock response after renal ischemia. Bioinformatic analysis predicted a molecular link to tubular immunogenicity at the level of the transcription factor HSF-1 that was experimentally verified by HSF-1 decoy treatment. Future studies in HSF-1 knockout mice are needed.

Effect of brain-dead donor resuscitation on delayed graft function: results of a monocentric analysis

BACKGROUND

We have previously shown that a delayed graft function (DGF) longer than 6 days was a crucial threshold for long-term graft outcome. The aim of this study was to analyze the correlation of DGF >or=6 days with brain-dead donor variables, including those related to resuscitation, in a population of 262 consecutive brain-dead donors from 1990 to 2003.

METHODS

We used a marginal logistic model in which DGF was considered as a binary variable with a cutoff of 6 days.

RESULTS

Monovariate analysis of donor parameters showed that male, age above 35 years, primary history of hypertension, hydroxyethyl starch (HES) fluid greater than 1500 mL or epinephrine infusion during resuscitation were risk factors for prolonged DGF. The multivariate logistic regression model showed that epinephrine use during donor resuscitation (P<0.001, odds ratio [OR]=4.35), cold ischemia time (CIT) >or=16 hr (P=0.01, OR=2.16), and recipient age >55 years (P=0.003, OR=2.75), were associated with a risk of prolonged DGF. A long stay (>40 hr) in intensive care and a large volume of colloids (>1250 mL, except HES) correlated with a lower risk of DGF.

CONCLUSION

Our study shows an impact for only a limited number of brain dead donor resuscitation parameters on DGF duration. We also show that CIT has a much lower threshold (<16 hr) for DGF risk than previously described. Importantly, we show that recipient age is clearly a major independent risk factor for prolonged DGF, whereas donor age seems to act mostly as a dependent risk factor.

Cyclosporine Prolongs Delayed Graft Function in Kidney Transplantation: Are Rabbit Anti-Human Thymocyte Globulins the Answer?

BACKGROUND

Cyclosporine (CsA) nephrotoxicity may prolong duration of anuria in renal transplant patients with delayed graft function (DGF). Thus, many Transplant Centers tend to delay CsA treatment in order to accelerate renal function recovery.

METHODS

In this single-center, retrospective analysis we compared the outcomes of 40 renal transplant patients with DGF given a CsA-based (n = 17) regimen since the day of transplant or a CsA-sparing regimen (n = 23) based on early treatment with rabbit anti-human thymocyte globulin (RATG) and delayed CsA administration. We studied all patients with DGF who received a first or second graft at the Bergamo Transplant Center from January 1992 to March 2000.

RESULTS

Patients given RATG as compared to those on CsA had significantly shorter duration of anuria (11.0 +/- 5.6 vs. 19.6 +/- 8.9 days; p < 0.005) and of initial hospitalization (17.4 +/- 4.3 vs. 27.4 +/- 10.4 days; p < 0.001). Throughout the whole study period, 4 patients on RATG as compared to 6 on CsA had an acute rejection episode (p > 0.05). However, no patient on RATG as compared to 4 on CsA had an acute rejection during the anuria period (p < 0.05). Costs including hospitalization, dialysis treatment and study drugs were significantly lower in RATG than in CsA patients (EUR 29,944 +/- 7,281 vs. 36,795 +/- 13,656; p < 0.05).

CONCLUSIONS

In renal transplant patients with DGF, early RATG treatment with delayed CsA administration accelerated renal function recovery and patient discharge, prevented occult rejections throughout the anuria period and significantly decreased the treatment costs.

Delayed graft function in kidney transplantation

Delayed graft function is a form of acute renal failure resulting in post-transplantation oliguria, increased allograft immunogenicity and risk of acute rejection episodes, and decreased long-term survival. Factors related to the donor and prerenal, renal, or postrenal transplant factors related to the recipient can contribute to this condition. From experimental studies, we have learnt that both ischaemia and reinstitution of blood flow in ischaemically damaged kidneys after hypothermic preservation activate a complex sequence of events that sustain renal injury and play a pivotal part in the development of delayed graft function. Elucidation of the pathophysiology of renal ischaemia and reperfusion injury has contributed to the development of strategies to decrease the rate of delayed graft function, focusing on donor management, organ procurement and preservation techniques, recipient fluid management, and pharmacological agents (vasodilators, antioxidants, anti-inflammatory agents). Several new drugs show promise in animal studies in preventing or ameliorating ischaemia-reperfusion injury and possibly delayed graft function, but definitive clinical trials are lacking. The goal of monotherapy for the prevention or treatment of is perhaps unattainable, and multidrug approaches or single drug targeting multiple signals will be the next step to reduce post-transplantation injury and delayed graft function.

Creatinine reduction ratio on post-transplant day two as criterion in defining delayed graft function

Delayed graft function (DGF) is a common complication after renal transplant, affecting its outcome. A common definition of DGF is the need for dialysis within the first week of transplantation, but this criterion has its drawbacks. We tried to validate an earlier and better defined parameter of DGF based on the creatinine reduction ratio on post-transplant day 2 (CRR2). We analyzed the clinical charts of 291 cadaver kidney recipients to compare the outcome of patients with immediate graft function (IGF), dialyzed patients (D-DGF) and nondialyzed CRR2-defined DGF patients (ND-DGF) and to identify risk factors for D-DGF and ND-DGF. Creatinine reduction ratio on post-transplant day 2 correlates significantly with renal function during the first year. Patients with IGF have significantly better renal function throughout the first year and better graft survival than patients with D-DGF and ND-DGF, while we found no differences either in renal function from days 30-365 or in graft survival between D-DGF and ND-DGF patients. Defining DGF by CRR2 allows an objective and quantitative diagnosis after transplantation and can help to improve post-transplant management. Creatinine reduction ratio on post-transplant day 2 correlates with renal function throughout the first year. The worse survival in the ND-DGF group is an important finding and a major advantage of the CRR2 criterion.

Weekend operating room on call staffing requirements

This article describes a statistical method used to determine the minimum number of OR teams that should be on call for urgent procedures, in-house versus on standby from home, to minimize labor costs. The OR manager obtains the number of ORs staffed at each hour of the 24-hour period of interest (e.g., 7 AM Saturday to 7 AM Sunday) from the surgical suite's information system. The minimum number of total staffed hours needed to care for patients is calculated for a prespecified level of the acceptable risk of inadequate staffing. A method used to determine whether each staff member should work in-house or on standby from home then is introduced. This method enumerates all possible combinations of shifts to find the one with the lowest cost, and it ensures a prespecified service level. An example based on 248 weeks of data collected from a large surgical suite is presented, and staffing for emergency procedures is reviewed.

Urinary thymidine glycol as a biomarker for oxidative stress after kidney transplantation

Reactive oxygen species are generated during ischemia-reperfusion tissue injury. Oxidation of thymidine by hydroxyl radicals (HO*) causes formation of 5,6-dihydroxy-5,6-dihydrothymidine (thymidine glycol). Thymidine glycol excreted in urine can be used as a biomarker of oxidative DNA damage. The aim of this study was to investigate the oxidative DNA damage in patients showing immediate allograft function after kidney transplantation, and to find out whether this damage correlates with glomerular and tubular lesions. Time dependent changes in urinary excretion rates of thymidine glycol, but also of total protein, albumin, low molecular weight (alpha1-microglobulin, beta2-microglobulin) and high molecular weight proteins (transferrin, IgG, alpha2-macroglobulin) were analyzed quantitatively and by polyacrylamide-gel electrophoresis in six patients. Urinary thymidine glycol was determined by a fluorimetric assay in combination with affinity chromatography and HPLC. After kidney transplantation the urinary excretion rate of thymidine glycol increased gradually reaching a maximum within the first 48 hours (16.56+/-11.3 nmol/m mol creatinine, ref. 4.3+/-0.97). Severe proteinuria with an excretion rate of up to 7.2 g/mmol creatinine was observed and declined within the first 24 hours of allograft function (0.35+/-0.26 g/mmol creatinine). The gel-electrophoretic pattern showed a nonselective glomerular and tubular proteinuria. The initial nonselective glomerular proteinuria disappeared within 48 hours, changing to a mild selective glomerular proteinuria. In this period (12-48 hours) higher levels of thymidine glycol excretion were observed, when compared to the initial posttransplant phase (13.66+/-9.76 vs. 4.31+/-3.61 nmol/mmol creatinine; p<0.05). An increased excretion of thymidine glycol is seen after kidney transplantation and is explained by the ischemia-reperfusion induced oxidative DNA damage in the kidney. In the second phase higher levels of excretion were observed parallel to the change from a nonselective to a selective glomerular and tubular proteinuria. An explanation may be sought in the repair process of DNA in the glomerular and tubular epithelial cells, appearing simultaneously with functional recovery.

Optimal sequencing of urgent surgical cases. Scheduling cases using operating room information systems

Optimal sequencing of urgent cases (i.e., selecting which urgent case should be performed first and which second) may enhance patient safety, increase patient satisfaction with timeliness of surgery, and minimize surgeons' complaints. Before determining the optimal sequence of urgent cases, an operating room (OR) suite must identify the primary scheduling objective to be satisfied when prioritizing pending urgent cases. These scheduling objectives may include: 1) perform the cases in the sequence that minimizes the average length of time each surgeon and patient waits; 2) perform the cases in the order that they were submitted; or 3) perform the cases based on medical priority, as prioritized by an OR director, or surgeons discussing the cases among themselves. We provide mathematical structure which can be used to program a computerized surgical services information system to assist in optimizing the sequence of urgent cases. We use an example to illustrate that the optimal sequence varies depending on the scheduling objective chosen.

Delayed graft function does not reduce the survival of renal transplant allografts

BACKGROUND

The aim of the present study was to investigate the effect of delayed graft function (DGF) in graft outcome when adjusted by the presence of acute rejection in the first month after transplantation.

METHODS

A total of 437 cadaveric renal transplant patients on cyclosporine and steroids were included in the study. Variables related to donor, recipient, and graft were prospectively collected.

RESULTS

The incidence of DGF was 44.4%. When patients dying with a functioning graft were censored, graft survival rates at 1 and 6 years were similar in patients with immediate function to those with DGF, when rejection was not present (96% and 81% vs. 95% and 83%, respectively). Rejection negatively influenced graft survival rates at 1 and 6 years, both in patients with immediate graft function (80% and 73%, P<0.05 vs. no DGF/no rejection) and more deeply in those with associated DGF (77% and 62%, P<0.001 vs. no DGF/no rejection). Rejection was more frequently diagnosed in patients with DGF than in those with immediate graft function (50% vs. 39.9%, P<0.05). Length of hospitalization was longer and the number of needle core biopsies was higher in patients with DGF or rejection. The presence of both complications had an additive effect.

CONCLUSIONS

This study showed that DGF did not adversely affect kidney graft survival in patients without rejection. However, it increased the length of hospitalization and the number of graft biopsies, thus increasing the cost of transplantation. Moreover, rejection was more frequent in patients with DGF, and it had a negative impact on graft outcome. Because the association of DGF and rejection gave the poorest outcome, an effort should be made to prevent both complications.

[Graft function following renal transplantation in children]

BACKGROUND

Since renal transplantation is known to be the best choice for the growing child with end-stage renal failure, we prospectively evaluated early and late graft function in transplanted children.

POPULATION AND METHODS

The study included 78 children (32 girls, 46 boys) 10.4 +/- 0.6 years at the time of transplantation. Renal investigations were performed at 3, 6 and 12 months post-transplantation and yearly thereafter. Inulin clearance was used to evaluate the glomerular filtration rate (GFR), and the reabsorption rates of Na, P and Ca were measured concomitantly.

RESULTS

The overall adjusted GFR was approximately 70 mL/min/1.73 m2 and remained unchanged during the first 5 years post-transplantation. In the mean time the absolute GFR increased significantly, suggesting a remaining capacity for compensatory hypertrophy of the transplanted kidney. Renal function was significantly influenced by the number of rejection episodes during the first 2 years post-transplantation but no correlation was found between GFR and the number of HLA mismatches or the use of preemptive transplantation.

Outcome of grafts with long-lasting delayed function after renal transplantation

To assess the impact of long-lasting acute renal failure after renal transplantation on late graft prognosis, we compared the risk factors and outcome in renal allografts with delayed function for >3 weeks after renal transplantation (long-lasting delayed graft function [LLDGF]) (group A, n=64), and in four control groups: group B, initially functioning grafts (n=322); group C, grafts with delayed function for <2 weeks after transplantation (n=110); group D, grafts with delayed function for 14 to 20 days after transplantation (n=57); and group E, never-functioning grafts (n=88). Donor asystolia or instability, stroke as a cause of donor's death, and prolonged cold ischemia and vascular surgical times were some predictors of LLDGF. Overlap was important, but 43% of patients of group A, 15% of group B, 25% of group C, 31% of group D, and 40% of group E (P<0.01) presented two or more risk factors for severe acute tubular necrosis after transplantation. Acute rejection and early complications were very frequent in group A. Also, patient survival was significantly decreased in group A, due to a higher incidence of infectious mortality. Graft survival was moderately (NS) decreased in group A. Serum creatinine was initially higher in patients of group A, but differences disappeared after the second year. However, late proteinuria was more frequent in group A, and there was also a trend for a higher prevalence of hypertension in this group. LLDGF cannot be reliably predicted at the time of renal transplantation. The main consequence of LLDGF is an excess mortality, while the impact on late graft function is less significant. Short-lasting delayed graft function does not seem to have a negative impact on the outcome of renal transplantation.

Delayed graft function in renal transplantation: etiology, management and long-term significance

PURPOSE

In cadaveric renal transplantation a period of delayed graft function postoperatively is not uncommon and often associated with a poor outcome. We reviewed the biology of reperfusion injury and delayed graft function in renal transplantation, as well as its prevention, management and long-term effects.

MATERIALS AND METHODS

The medical literature covering acute tubular necrosis, delayed graft function in renal transplantation and immunology of ischemia reperfusion injury was reviewed.

RESULTS

Delayed graft function is clearly associated with poor allograft survival, and is caused by an interaction of ischemic and immunological factors. Technical and pharmacological maneuvers can improve early function rates. The response to ischemic injury is complex, and may increase graft immunogenicity and promote the chronic proliferative changes seen in chronic allograft nephropathy.

CONCLUSIONS

Improvement in early renal function should be a primary goal in renal transplantation to enhance early and long-term results. Basic research into the injury response may yield insights into renal pathophysiology.

Nifedipine does not affect free radical induced lipid peroxidation following renal allograft reperfusion

We prospectively measured lipid peroxidation following reperfusion during 44 renal allograft transplant operations. Twenty-four (55%) recipients were taking nifedipine pre- and then postoperatively, and 20 (45%) were not. There were no differences between the groups in terms of recipient or donor status. Plasma malondialdehyde (MDA), mean 2.2 (0.2) mumol/L (SEM) vs. 1.73 (0.1) was greater in the group not prescribed nifedipine, p < .05, as were cholesterol; 5.89 (0.3) mmol/L vs. 5.58 (0.3) and triglycerides; 2.19 (0.2) mmol/L vs. 1.82 (0.2). Following allograft reperfusion there was a significant increase in the ratio of MDA/cholesterol (x 10(3)) (MDA corrected for changes in plasma volume) from 0.33 (0.03) in the nifedipine group to 0.38 (0.02) at 30 min after reperfusion and 0.38 (0.03) at 60 min, p < .01, and similarly from 0.4 (0.04) to 0.48 (0.03) at 30 min and 0.47 (0.05) after 60 min in the other group, p < .01. There was no difference in the percentage change in MDA/cholesterol ratio between the groups; 27 (5)% vs. 19 (6) at 30 min and 20 (8) vs. 15 (8) at 60 min for the nifedipine and no-nifedipine groups, respectively. There was no difference in postoperative renal function between the groups. This study suggests that the oral administration of nifedipine may not prevent the production of lipid peroxides, as measured by changes in plasma malondialdehyde, following renal allograft reperfusion and that it does not affect renal function in the early postoperative period.

Non-immunological risk factors in paediatric renal transplantation

In paediatric renal transplantation, non-immunological risk factors account for about one-third of graft losses. Recurrence of original disease is observed mainly in primary hyperoxaluria and glomerulopathies such as steroid-resistant nephrotic syndrome and membranoproliferative glomerulonephritis. In both glomerulopathies, 20% of grafts are lost from recurrence. Vascular thrombosis is, in most series, the second cause of graft loss in children, particularly in young recipients or with young donors (under 5 years of age). Non-compliance with treatment is a common non-immunological factor in adolescent recipients, which may trigger a severe rejection process resulting in graft loss. The role of factors related to graft preservation and intra- and post-operative management (ischaemia time, delayed graft function) or to cytomegalovirus infection is less obvious in our series. Prevention of vascular thrombosis and of non-compliance is most important in order to improve the results of paediatric renal transplantation.