Calcium levels as a risk factor for delayed graft function

BACKGROUND: Delayed graft function (DGF) occurs in up to 50% of renal transplants. Hypercalcemia and hyperparathyroidism are associated with impaired renal function. Little is known on the effects of serum calcium levels on DGF. This issue was addressed in the current study. METHODS: Patients receiving a cadaveric renal transplant between 1986 and 1996 were studied. Data on calcium metabolism and histologic characteristics of nephrocalcinosis, acute tubular necrosis (ATN), and acute rejection in biopsies taken within the first week were related to the occurrence of DGF. RESULTS: The incidence of DGF in a cohort of 585 cadaveric transplants was 31%. DGF correlated independently with serum calcium levels (odds ratio [OR] 1.14 [95% confidence interval (CI) 1.04-1.26] per 0.1 mmol/L). The use of calcium channel blockers before transplantation protected against DGF (OR 0.5 [95% CI 0.29- 0.87]). In this selected group, we found an association with histologic signs of ATN and DGF. However, most of the biopsies also had features of acute rejection or nephrocalcinosis. Nephrocalcinosis was found in 12 of 71 biopsies and was not associated with serum calcium levels or the occurrence of DGF. CONCLUSIONS: In this study, serum calcium levels were independently associated with DGF. This could not be explained by the presence of microscopic nephrocalcinosis. Therefore, DGF is attributed to high intracellular calcium levels. Because calcium supplementation and vitamin D analogues are commonly used in dialysis practice, hypercalcemia influences long-term graft outcome by its effect on DGF. The pretransplant use of calcium channel blockers has a protective effect on the occurrence of DGF.     

Incidence of delayed graft function in cadaveric kidney transplants in Brazil: a multicenter analysis

To evaluate the frequency of delayed graft function (DGF) in kidney transplant centers in Brazil, we sent a questionnaire requesting information on the number of cadaveric donor kidney transplants performed during the years 2000, 2001, and 2002, the number of early nonfunctioning grafts, and the number of patients on dialysis during the first posttransplant week with subsequent recovery. Among all centers performing more than 50 kidney transplants during the last year of evaluation, 6, performing 612 cadaveric kidney transplants during the study period, replied to the questionnaire. Sixty procedures (9.7%) resulted in nonfunctioning grafts, while 312 (55.6%) patients required dialysis during the first Ptx week: 216 (53.9%) in 2000, 189 (62.3%) in 2001, and 216 (51.6%) in 2002. The frequency of DGF during the study period was higher than that noted by several previous foreign studies. To better evaluate the possible causes of this finding, a more extensive and focused study is warranted.     

Reduced graft function (with or without dialysis) vs immediate graft function--a comparison of long-term renal allograft survival.

BACKGROUND: Delayed graft function (DGF) is a common complication in cadaveric kidney transplants affecting graft outcome. However, the incidence of DGF differs widely between centres as its definition is very variable. The purpose of this study was to define a parameter for DGF and immediate graft function (IGF) and to compare the graft outcome between these groups at our centre. METHODS: The renal allograft function of 972 first cadaveric transplants performed between 1990 and 2001 in the Republic of Ireland was examined. The DGF and IGF were defined by a creatinine reduction ratio (CRR) between time 0 of transplantation and day 7 post-transplantation of <70 and >70%, respectively. Recipients with reduced graft function (DGF) not requiring dialysis were defined as slow graft function (SGF) patients. The serum creatinine at 3 months, 6 months, 1, 2 and 5 years after transplantation was compared between these groups of recipients. The graft survival rates at 1, 3 and 5 years and the graft half-life for DGF, SGF and IGF recipients were also assessed. RESULTS: Of the 972 renal transplant recipients, DGF was seen in 102 (10.5%) patients, SGF in 202 (20.8%) recipients and IGF in 668 (68.7%) patients. Serum creatinine levels were significantly different between the three groups at 3 and 6 months, 1, 2 and 5 years. Graft survival at 5 years for the DGF patients was 48.5%, 60.5% for SGF recipients and 75% for IGF patients with graft half-life of 4.9, 8.7 and 10.5 years, respectively. CONCLUSION: This study has shown that the CRR at day 7 correlates with renal function up to 5 years post-transplantation and with long-term graft survival. We have also demonstrated that amongst patients with reduced graft function after transplantation, two groups with significantly different outcomes exist.     

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: risk factors and the relative effects of early function and acute rejection on long-term survival in cadaveric renal transplantation

Delayed graft function (DGF) and acute rejection have both been associated with reduced renal allograft survival. In some studies, they have been shown to have an interactive effect. We studied the risk factors for DGF and the relative impact of DGF and rejection on both short- and long-term survival in recipients of cadaveric renal transplants. Data from the Oxford Transplant Centre Database were assessed on 710 cadaver allografts over a 10-yr period, during which time all recipients received cyclosporin-based immunosuppressive protocols. The interaction between DGF and acute rejection was examined using logistic and Cox multivariate regression. Long cold ischaemia time (CIT), sensitisation and older donor age were found to be independent predictors of DGF. The occurrence of DGF resulted in a reduced 5-yr survival (56 vs. 75%). However, the effect of DGF was confined to the first year post-transplant, as there was no significant difference in survival, as measured by half-life (t1/2) of grafts functioning at 1 yr, with DGF alone and a group with good early function (t1/2 = 21.3 vs. 20.0 yr). There was no increase in acute rejection in grafts with DGF. However, the combination of DGF and acute rejection resulted in the worst short-term graft survival (68% at 1 yr, compared to 92.3% in those grafts with no DGF or acute rejection) and this continued over the long term (t1/2 = 10.5 yr). These data suggest that early function is critical to the success of renal transplantation. The effects of DGF are limited to the first year post-transplant. Long-term graft survival may be improved by efforts to limit CITs, particularly for grafts from older donors and sensitised recipients.     

Hepatitis C, acute humoral rejection, and renal allograft survival

The effect of recipient hepatitis C virus (HCV) infection on renal allograft loss and acute rejection in kidney transplantation remains controversial. We studied 354 renal allograft recipients transplanted during 1996 to 2001 who had HCV antibodies (Ab) measured before transplantation. The primary outcome was death-censored allograft loss and the secondary outcome was acute humoral rejection (AHR). Compared with HCV Ab-negative patients, those with positive HCV Ab had longer time on dialysis before transplantation, higher percentage of panel-reactive antibodies (PRA), were more likely to receive a cadaveric transplant, and were more likely to develop delayed graft function (DGF). In univariate analyses, predictors of renal allograft loss included HCV, cadaveric graft, PRA >20%, HLA mismatch > or =5, retransplantation, DGF, induction therapy, and AHR. When adjusted for PRA >20%, HLA mismatch > or =5, and multiple transplant status, HCV was not a statistically significant predictor of allograft loss. HCV was also associated with AHR but lost significance when adjusted for PRA >20%. HCV Ab-positive patients were more likely to have longer duration of dialysis before transplantation prior to kidney transplants, higher PRA, and to receive cadaveric transplants. These characteristics likely resulted in more DGF and AHR after transplantation. After adjusting for these confounding factors, the association between HCV Ab positivity and renal allograft loss was notably attenuated and no longer statistically significant.     

Creatinine reduction ratio and 24-hour creatinine excretion on posttransplant day two: simple and objective tools to define graft function

To devise objective criteria for early diagnosis of delayed graft function (DGF), 59 adult living donor kidney transplants with immediate graft function (IGF) and 51 cadaveric kidney transplants were investigated for creatinine reduction ratio (CRR2) from posttransplant day 1 to day 2 and 24-h urine creatinine excretion (UC2) on day 2. The mean CRR2 in living donor transplants was 53% (SD +/- 11); the distribution of CRR2 was gaussian, and all of them had UC2 >1000 mg. Criteria for DGF were developed on the basis of living donor transplant: CRR2 < or =30% (2SD below 53%) +/- UC2 < or =1000 mg. Overall, 24 cadaver transplant recipients (47%) developed DGF (CRR2 < or =30%); 13 patients (25%) had mild DGF (UC2 >1000 mg), and the remaining 11 (22%) had severe DGF (UC2 < or =1000 mg). All the patients with severe DGF had a measured creatinine clearance <25 ml/min on day 7, and 8 of 11 were dialyzed within the first week of transplantation. Patients with IGF and mild DGF had a creatinine clearance of > or =25 ml/min on or before day 7, and none of them were dialyzed. Calcineurin inhibitors were avoided or delayed in five patients with mild DGF and all patients with severe DGF. In conclusion, diagnosing DGF within 48-h after transplantation is simple and may be valuable in the management of these patients.     

Prediction of delayed renal allograft function using an artificial neural network.

BACKGROUND: Delayed graft function (DGF) is one of the most important complications in the post-transplant period, having an adverse effect on both the immediate and long-term graft survival. In this study, an artificial neural network was used to predict the occurrence of DGF and compared with traditional logistical regression models for prediction of DGF. METHODS: A total of 304 cadaveric renal transplants performed at the Jewish Hospital, Louisville were included in the study. Covariate analysis by artificial neural networks and traditional logistical regression were done to predict the occurrence of DGF. RESULTS: The incidence of DGF in this study was 38%. Logistic regression analysis was more sensitive to prediction of no DGF (91 vs 70%), while the neural network was more sensitive to prediction of yes for DGF (56 vs 37%). Overall prediction accuracy for both logistic regression and the neural network was 64 and 63%, respectively. Logistic regression was 36.5% sensitive and 90.7% specific. The neural network was 63.5% sensitive and 64.8% specific. The only covariate with a P < 0.001 was the transplant of a white donor kidney to a black recipient. Cox proportional hazard regression was used to test for the negative effect of DGF on long-term graft survival. One year graft survival in patients without DGF was 92 +/- 2% vs 81 +/- 3% in patients with DGF. The 5-year graft survival was not affected by DGF in this study. CONCLUSION: Artificial neural networks may be used for prediction of DGF in cadaveric renal transplants. This method is more sensitive but less specific than logistic regression methods.     

Immunologic and nonimmunologic factors: different risks for cadaver and living donor transplantation

BACKGROUND: There is a debate about the relative contribution of immunologic (rejection) and nonimmunologic (limited nephron mass) factors in long-term graft survival. METHODS: Using multivariate analysis, we studied the association of the following variables with outcome: delayed graft function (DGF), acute rejection, recipient race (black vs. nonblack), donor age (<50 vs. > or =50), donor race, and donor and recipient gender. Because of the association between DGF and rejection, recipients were grouped as follows: DGF, rejection; DGF, no rejection; no DGF, rejection; no DGF, no rejection. Data were analyzed on 1199 first kidney transplants in adults (752 living donor, 447 cadaver donor) done between January 1, 1985 and December 31, 1996. Two analyses were done: first, all transplants; second, only those with > or =1 year survival. For both, there was no difference in risk factors if death with function was or was not censored. RESULTS: For all cadaver transplant recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50. For living donor recipients, only acute rejection was a risk factor. When only 1-year graft survivors were considered, risk factors were the same: for cadaver recipients, risk factors were acute rejection, DGF plus rejection, black recipient race, and donor age > or =50; for living donor recipients the risk factor was rejection. CONCLUSION: We found immunologic factors (rejection with or without DGF) to be significant in both living donor and cadaver donor transplants. Nonim. munologic factors (donor age, recipient race) were significant only in cadaver donor transplants.     

Renal transplantation done safely without prior chronic dialysis therapy

The complications, cost, and inconvenience associated with pretransplant hemodialysis and peritoneal dialysis would be minimized if transplantation were instituted without prior dialysis. That preuremic transplantation is safe and efficacious in patients with immanent end-stage renal disease has not been established. All 1742 consecutive primary renal transplants performed at the University of Minnesota during the 16.5 year period from January 1968 through July 1984 were reviewed to determine whether graft and patient survival were adversely affected by transplantation prior to dialytic therapy. In the overall group of primary renal transplants, no differences in actuarial graft or patient survival were noted with or without prior dialysis. Likewise, outcome was not affected by the pretransplant dialysis status in recipients of allografts from HLA-identical mismatched living-related donors. However, in cadaveric transplantation graft function appeared to be adversely affected by transplantation prior to dialysis, with 52% vs. 66% two-year graft function for nondialyzed vs. chronically dialyzed recipients, respectively (P = 0.15). Patient survival was significantly (P = .04) decreased in the nondialyzed group, with 66% vs. 80% two-year survival in the chronic dialysis group. However, nearly all of the nondialyzed, cadaveric recipients were diabetic. The outcome of transplantation was found to be identical in these patients, as compared with chronically dialyzed diabetic recipients of cadaveric grafts. Thus, the apparent detrimental effect of predialytic transplantation in the cadaver group was due to the preponderance of diabetics in the nondialyzed group. Since July 1984, a single-armed therapeutic trial of combination therapy with azathioprine, prednisone, antilymphoblast globulin (ALG), and cyclosporine has been undertaken, Since that time, 36 primary graft recipients were transplanted prior to dialysis. Of these 36, 35 currently have a functioning graft. Thus, transplantation prior to chronic dialysis is safe irrespective of donor source, or choice of immunosuppressive agents.     

A trial of thyroxine in acute renal failure

A trial of thyroxine in acute renal failure. BACKGROUND: Acute renal failure (ARF) remains a serious medical problem with a high mortality rate. Efforts to shorten the course of ARF might reduce this mortality. Since thyroxine has been shown in experimental models to shorten the course of ARF, we designed a trial to determine if a defined course of thyroxine would alter the course or change the mortality of clinical ARF. METHODS: A prospective, randomized, placebo-controlled, double-blind trial of thyroxine was carried out in patients with ARF. End points were the percentage requiring dialysis, the percentage recovering renal function, time to recovery, and mortality. RESULTS: Fifty-nine patients were randomized to receive either thyroxine or placebo. The groups were well matched in terms of basal and entry creatinines, age, sex, APACHE II scores at entry, and percentage oliguric. Baseline thyroid functions, including T3, T4, rT3, and thyroid stimulating hormone (TSH) levels, were equal between the two groups and typical of patients with euthyroid sick syndrome. Thyroxine resulted in a progressive and sustained suppression of TSH levels in the treated group, but had no effect on any measure of ARF severity. Mortality was higher in the thyroxine group than the control group (43 vs. 13%) and correlated with suppression of TSH. CONCLUSIONS: In contrast to the beneficial effects seen in experimental ARF, thyroxine has no effect on the course of clinical ARF and could have a negative effect on outcome through prolonged suppression of TSH. Critically ill euthyroid sick patients should not be replaced with thyroid hormone.     

Delayed graft function: risk factors, consequences and parameters affecting outcome-results from MOST, A Multinational Observational Study

BACKGROUND: Delayed graft function (DGF) is a common complication after renal transplantation, and may affect graft function. The aim of this analysis was to evaluate risk factors for DGF, as well as parameters and events influencing graft function after DGF. We analyzed data collected in an ongoing international, prospective; observational study, the Neoral-MOST (Multinational Observational Study in renal Transplantation), and included in the analysis all patients with cadaveric kidney transplants for whom renal function at 1 year posttransplantation was documented (N = 8950). Logistic regression was used to evaluate the risk factors for DGF occurrence, and multifactorial analysis of variance (ANCOVA) to assess the relevance of different factors for GFR at 1 year. RESULTS: Higher donor age, longer CIT, male recipients, Caucasian recipients, high recipients body mass index, and PRA were all associated with a higher risk for DGF. Renal function of former DGF kidneys at 1 year was lower in kidneys of elder donors, or which had experienced rejection or CMV infection. Variations of the maintenance regimen at 1 year posttransplantation were not associated with better graft function. Multifactorial analysis showed donor age and acute rejection as significant independent factors. CONCLUSIONS: Most factors increasing the risk for DGF or having a negative impact on renal function at 1 year in grafts with DGF are predetermined. Additional posttransplant damage by acute rejection was associated with further reductions in GFR. Preventing acute rejection is an important step in achieving optimal function of DGF grafts.     

Impact of the delayed graft function in hypersensitized kidney transplant patients

AIM: The aim was to study the incidence, impact, and association of pretransplantation anti-HLA antibodies and delayed graft function (DGF) on the outcome of cadaver kidney transplants independent of the immunosuppressive therapy. METHODS: Data from 1325 cadaver donor kidneys (February 1975 to December 2002) included the variables of current and peak anti-HLA antibodies, presence of DGF, acute rejection (AR) episodes, patient survival, and graft half-life. RESULTS: DGF (need for dialysis in the first week posttransplantation) ranged between 15% and 40% with a mean of 30% in last 5 years. Eighty-five percent of the candidates on the waiting list for kidney transplants displayed <25% panel reactive antibody (PRA) at transplantation with 4.6% between 26% and 50%, 7.7% between 51% and 75%, and 1.5% >75%. Among the patients who developed DGF, 47% displayed AR compared an incidence of 30% among patients without DGF (P=.0026). The patients displaying >50% PRA (either current or maximum) showed a worse graft survival compared with patients with <50% PRA (log rank, P=.0000). DGF reduced graft survival (P=.04), the difference appearing in the early phase after transplantation. The best outcome was observed in the no DGF-no AR group (half-life, 11.6 years) and the worst results were in the hypersensitized patient groups: peak and current PRA >50% (half-lives of 2.4 and 2.2 years). A multivariate analysis showed that the presence of peak or current PRA >50% is the most important risk factor for graft loss. CONCLUSION: Sensitization is the key factor in graft outcome. Presensitization increases the risk of DGF and DGF increases the incidence of AR and both together produce the worst graft survivals.     

肾移植术后导致肾功能恢复延迟的危险因素分析

目的探讨肾移植术后发生肾功能恢复延迟(DGF)的危险因素。方法对肾移植术后发生DGF的111例患者(DGF组)及同期未发生DGF的141例患者(对照组)的临床资料进行回顾性分析,用χ2检验进行单因素分析,用Logistic进行多因素回归分析,计算其相对危险度。结果单因素及多因素分析表明,冷缺血时间,热缺血时间,术中、术后早期低血压,群体反应性抗体阳性,急性肾小管坏死,加速性排斥反应,神经钙调素抑制剂肾毒性,术后早期尿漏、输尿管梗阻等8种因素是发生DGF的危险因素。结论术前、术中及术后早期的多种因素均能导致DGF,其发生基础为缺血-再灌注损伤,应针对多种危险因素采取综合预防措施。     

Why do patients with postsurgical acute tubular necrosis die?

We compared early (less than 70 days) cumulative survival, cause of death, and morbidity (defined as the number of organ system failures and reoperations) of 236 patients who needed dialysis for acute tubular necrosis (ATN) after transplantation with that of a control group of 215 transplant patients who had immediate renal function after transplantation. The patients were matched for age, number of transplants, time of transplantation, diabetic status, living-related vs cadaveric donor, and number of HLA matches. There were no differences in cumulative survival after transplantation, causes of death, organ system failure, or surgical complications as evident from the number of reoperations. The ATN patients' overall clinical course was similar to that described for other postsurgical patients with ATN in their native kidneys. We conclude that the poor survival and the surgical complications in patients with postoperative ATN are due to the basic disease and not to acute renal failure or to dialysis. To improve survival, research should be focused on the basic disease and the surgical procedures rather than on dialysis technique.     

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.     

Comparison of outcomes after delayed graft function: sirolimus-based versus other calcineurin-inhibitor sparing induction immunosuppression regimens

BACKGROUND: Sirolimus (SRL) may increase the incidence of or prolong delayed graft function (DGF) after cadaveric renal transplantation. This study compares transplant outcomes of SRL-based induction immunosuppression (IS) with other calcineurin-inhibitor (CNI) sparing regimens in the DGF setting. METHODS: Adult cadaveric renal-transplant recipients who received transplants between January 1, 1997 and June 30, 2001 and experienced DGF (n=132) were divided into three groups by induction IS: A, depleting antibody (n=41); B, SRL (n=49); and C, neither (n=42). All recipients also received steroids and mycophenolate mofetil with delayed initiation of CNIs when good renal function returned. Patient survival, graft survival, and time to rejection within 1 year of transplantation were assessed by Kaplan-Meier analysis. One-year graft function was compared using Kruskal-Wallis and Fisher's exact tests. RESULTS: The SRL group had longer DGF duration (P=0.01). The three groups had comparable patient (P=0.27) and graft survival (P=0.69), but the depleting antibody group experienced less rejection (P=0.004). There were no clinically significant differences in 1-year graft function. CONCLUSIONS: In our analysis of a large and modern cohort of adult cadaveric transplant recipients with DGF, induction immunosuppression with a depleting antibody preparation reduced rejection, whereas SRL prolonged DGF duration. All three CNI-sparing induction IS regimens resulted in comparable patient survival, graft survival, and 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.     

Delayed Graft Function in Renal Transplant Recipients: Risk Factors and Impact on 1-Year Graft Function: A Single Center Analysis

Delayed graft function (DGF), a frequent complication after kidney transplantation, occurs among about 60% of recipients of kidneys from deceased donors. DGF has a multifactorial etiology. It is characterized by acute tubular necrosis (ATN) upon biopsy. In this study we sought to identify among a group of recipients of kidneys from deceased donors, the incidence, risk factors, and impacts on patient and graft survivals of DGF.

Materials and Methods

We retrospectively analyzed medical records from renal transplant recipients aged >18 years who received a deceased donor kidney graft between January 2003 and December 2006. Kidneys lost during the first week posttransplantation were excluded from this series.

Results

Among 165 transplants, 111 (67%) displayed DGF, defined as the need for dialysis during the first week posttransplantation. The incidence of DGF was higher among patients with a cold ischemia time (CIT) > 24 hours: 85% vs 60%, DGF vs no DGF (P < .05), as well as for grafts from older donors. After 1-year follow-up, the DGF group showed worse graft function (serum creatinine 1.6 ± 0.7 vs 1.3 ± 0.4 mg/dL; P < .05) as well as a greater incidence of graft loss.

Conclusion

Prolonged cold ischemia and older donor age were associated with a greater incidence of DGF in this series, leading to prolonged hospitalization, increased risk for an acute rejection episode, and reduced graft function and survival after 1 year.     

Recovery of Graft Function Early Posttransplant Determines Long-Term Graft Survival in Deceased Donor Renal Transplants

Introduction

Because kidneys show remarkable resilience and can recover function, we examined the impact on long-term graft survival in deceased donor renal transplants of both immediate graft function (IGF) and the rate of renal function recovery over the first 3 months after transplantation.

Methods

We included all cadaveric renal transplants from 1990 to 2007 (n = 583). Delayed graft function (DGF) was defined as the need for dialysis in the first 7 days posttransplant. Slow graft function (SGF) and IGF were defined by serum creatinine falls of <20% or >20% in the first 24 hours posttransplant respectively. Recovery of renal function was expressed as either the best creatinine clearance (CrCl) in the first 3 months post-renal transplantation (BCrCl-3mos) as calculated using the Cockcroft-Gault formula or as a percentage of actual versus expected value (as calculated from the donors' CrCl at procurement).

Results

There were 140 (23.6%) subjects who received extended criteria donor (ECD) organs. The overall graft survival at 1 and 5 years was 87.8% and 74%, respectively. The 5-year graft survivals for patients with IGF, SGF, and DGF were 85%, 76%, and 54%, respectively (P < .02). ECD kidneys showed twice the DGF rate (49% vs 23%, P < .001). BCrCl-3mos of <30 mL/min displayed a 5-year graft survival of 34%; 30 to 39 mL/min, 72%; 40 to 49 mL/min, 85%; and >50 mL/min, 82% (P < .001). Similarly, a recovery within 90% of expected CrCl in the first 3 months posttransplant correlated with 5-year graft survival of 81%; a recovery of 70% to 90%, with 65%; and a recovery of <70%, with 51% (P < .001).

Conclusion

Early graft function in the first 3 months showed a significant impact on long-term graft survival after deceased donor renal transplantation.