Survival Of Kidney Transplant Recipients Research Articles

Risk Factors for Hypertension After Living Donor Kidney Transplantation in Korea: A Multivariate Analysis

BackgroundPost-transplantation hypertension is very common and is associated with cardiovascular complications and poor graft survival in kidney transplant recipients. This study aimed to identify risk factors for hypertension after living donor kidney transplantation. MethodsWe retrospectively analyzed patients who underwent renal transplantation between January 2009 and April 2012. Hypertension was defined as the use of antihypertensive medications at 12 months post-transplantation. Student t test and chi-squared test were performed for univariate analysis. Logistic regression analysis was performed for multivariate analysis. ResultsFive-hundred thirty-nine patients were enrolled in the analyses. The rate of antihypertensive medication use was 67% at 12 months. In multivariate analysis, male gender (odds ratio [OR], 2.68; 95% confidence interval [CI], 1.55–4.61), pretransplantation hypertension (OR, 4.65; 95% CI, 2.14–10.11), donor hypertension (OR, 3.23; 95% CI, 1.05–9.96), high body mass index (BMI; OR, 1.21; 95% CI, 1.12–1.29), and use of cyclosporine (OR, 2.05; 95% CI, 1.28–3.27) were associated with post-transplantation hypertension. ConclusionThese data show that male recipient, hypertension before transplantation, donor hypertension, high BMI, and cyclosporine use were independent factors associated with hypertension. It would be useful to predict and prevention the hypertension after kidney transplantation.

Cancer-Specific and All-Cause Mortality in Kidney Transplant Recipients With and Without Previous Cancer.

For dialysis patients with a cancer history, a period of surveillance is generally recommended before listing for transplantation. However, the outcomes of patients with cancer recurrence and/or a second primary cancer after transplantation are unknown. To determine the prognosis of kidney transplant recipients who developed cancer after transplantation and whether this varied with cancer types (first cancer, recurrence, second primary cancer). Using data from the Australian and New Zealand Dialysis and Transplant Registry, we compared the cancer-specific and all-cause mortality among recipients with different cancer types using adjusted Cox proportional hazard models. Of the 21,415 recipients transplanted between 1965 and 2012, 3% (651 of 21,415) had a previous cancer history. A total of 2840 (13%) recipients developed cancer after the first transplant, of whom 2760 (97.2%) developed a first cancer, 23 (0.8%) experienced cancer recurrence, and 57 (2%) developed a second primary cancer. There were no significant differences in the risks of cancer-specific and all-cause mortality between recipients who developed their first cancer after transplant, those with cancer recurrence (adjusted hazard ratios [aHRs], 0.79; 95% confidence interval [95% CI], 0.38-1.67; P = 0.54 and aHRs, 0.86; 95% CI, 0.45-1.66; P = 0.66, respectively) and recipients who developed a second primary cancer after transplantation (aHRs, 1.01; 95%CI, 0.63-1.62; P = 0.95 and aHRs, 1.16; 95% CI, 0.79-1.69; P = 0.45, respectively). Among patients with a previous history of malignancy, recurrent and second primary cancers are infrequent after renal transplantation. A history of previous malignancy does not have an additive effect on the cancer-specific and overall survival of kidney transplant recipients who develop cancer.

The impact of blood transfusions in deceased organ donors on the outcomes of 1,884 renal grafts from United Network for Organ Sharing Region 5.

Historically, strategies to reduce acute rejection and improve graft survival in kidney transplant recipients included blood transfusions (BTs) before transplantation. While advents in recipient immunosuppression strategies have replaced this practice, the impact of BTs in the organ donor on recipient graft outcomes has not been evaluated. We hypothesize that BTs in organ donors after neurologic determination of death (DNDDs) translate into improved recipient renal graft outcomes, as measured by a decrease in delayed graft function (DGF). Donor demographics, critical care end points, the use of BTs, and graft outcome data were prospectively collected on DNDDs from March 2012 to October 2013 in the United Network for Organ Sharing Region 5 Donor Management Database. Propensity analysis determined each DNDD's probability of receiving packed red blood cells based on demographic and critical care data as well as provider bias. The primary outcome measure was the rate of DGF (dialysis in the first week after transplantation) in different donor BT groups as follows: no BT, any BT, 1 to 5, 6 to 10, or greater than 10 packed red blood cell units. Regression models determined the relationship between donor BTs and recipient DGF after accounting for known predictors of DGF as well as the propensity to receive a BT. Data were complete for 1,884 renal grafts from 1,006 DNDDs; 52% received any BT, 32% received 1 to 5 U, 11% received 6 to 10, and 9% received greater than 10 U of blood. Grafts from transfused donors had a lower rate of DGF compared with those of the nontransfused donors (26% vs. 34%, p < 0.001). After adjusting for known confounders, grafts from donors with any BT had a lower odds of DGF (odds ratio, 0.76; p = 0.030), and this effect was greatest in those with greater than 10 U transfused. Any BT in a DNDD was associated with a 23% decrease in the odds of recipients developing DGF, and this effect was more pronounced as the number of BTs increased. Therapeutic study, level III; epidemiologic/prognostic study, level II.

Reductions in immunosuppression after haematological or solid organ cancer diagnosis in kidney transplant recipients.

Few data exist on how immunosuppression is altered in kidney transplant recipients (KTR) following a diagnosis of cancer. This study investigated how immunosuppression was altered in KTR after cancer diagnosis and its effect on patient and graft survival. All KTR diagnosed with cancer at our centre from 1990 to 2012 were assessed. Drug regime and serum creatinine levels were recorded 1year before, at time of, and 1year after cancer diagnosis. Of 87 KTR who developed cancer (7.3% of transplanted population, n=1189), 30 developed haematological malignancies and 57 developed solid organ cancers (SOC). In total, 38% of KTR presented with nodal or metastatic disease and 23 of 87 (26%) KTR died within 6months of cancer diagnosis. Fifty-five KTR had records of pre- and postcancer diagnosis drug regimes. Thirty-six KTR had a (>50%) dose reduction or cessation of 1 or more immunosuppressive agents, and 19 no reduction in immunosuppression. In total, 2 of 36 (6%) of KTR who underwent a dose reduction suffered acute rejection that was reversed with methylprednisolone. Dose reduction/cessation of immunosuppression did not impair graft function, but also did not affect cancer free survival. Further larger prospective studies are needed to determine whether dose reduction alters relapse free cancer survival in KTR.

HLA Gene Dosage Effect on Renal Allograft Survival

BackgroundHuman leukocyte antigen (HLA)-A, HLA-B, and HLA-DR matching has beneficial long-term effects on renal allograft survival. However, the gene dosage effect of mismatched HLA on transplant outcomes is not known. We investigated the HLA gene dosage effects on allograft survival in kidney transplant recipients (KTRs). MethodsWe analyzed HLA typing of KTRs and kidney donors at Kyungpook National University Hospital from January 1982 to December 2012. KTRs were divided into 2 groups: recipients from homozygous HLA donors and recipients from heterozygous HLA donors. Death-censored graft survival of KTRs was compared according to allele state of kidney donors. ResultsIn this study, 697 KTRs were enrolled. According to Kaplan-Meier analysis, graft survival in KTRs of HLA-DR and HLA-B heterozygous donors was longer than that in KTRs of HLA-DR and HLA-B homozygous donors (P = .007 and P < .0001, respectively). Multivariate Cox proportional hazards model analysis showed that HLA-DR and HLA-B donor homozygosity was an independent risk factor for death-censored graft survival (P = .019 and P = .022, respectively). Death-censored graft survival was not associated with HLA-A and HLA-A, B, DR allele states. ConclusionsCompared with HLA donor mismatch caused by HLA-DR and HLA-B heterozygosity, HLA donor mismatch caused by HLA-DR and HLA-B homozygosity was associated with significantly increased risk of graft failure. In addition to the number of HLA mismatch between KTRs and donors, the donor allele state should be considered to predict transplant outcomes.

Impact of ESRD Diagnosis On Graft Survival of Kidney Transplant Recipients of Small Pediatric Kidneys.

Outcomes of kidneys from small pediatric donors may be improved by optimal recipient selection. Etiology of ESRD may be a discerning risk factor for poor outcomes. SRTR data from 1995-2010 of adult deceased-donor KTXs were assessed for recipients of pediatric kidneys from donors <6 years of age compared to KTX from donors 17-34 years of age. Exclusions were multiorgan transplants, donor ≤10 kg, and recipient HCV/HIV seropositivity. Only those with ESRD due to diabetes mellitus (DM), hypertension (HTN) and immune-mediated disease (IMD, at least 1 of the following: SLE, MGN, FSGS) were included in the cohort. Other etiologies of ESRD were not assessed due to low sample size. On univariate analysis, death-censored graft survival (DCGS) time to event curves were significantly different between PEDS-donor single (SK), en bloc (EB), and ADULT-donor groups within each disease etiology.Figure: No Caption available.On multivariate Cox regression analyses (adjusted for donor and recipient risk factors) transplantation from a PEDS-donor with a single kidney was associated with a significantly increased risk of DCGS in recipients with DM (aHR 2.41, 95%CI 1.79-3.26), HTN (aHR 2.38, 95%CI 1.84-3.09), and IMD (aHR 2.46, 95%CI 1.74-3.46) compared to receiving an ADULT-donor kidney. Transplantation with an EB PEDS-donor kidney was associated with a significantly increased risk of DCGS in recipients with DM (aHR 1.78, 95%CI 1.27-2.48), but not HTN (aHR 1.04; 95%CI 0.77-1.41) or IMD (aHR 1.13, 95% CI 0.76-1.67). Single kidney transplantation from small pediatric donors is associated with similar risks (approximately 2.4 fold) of DCGS regardless of disease etiology. En bloc pediatric grafts are associated with worse DCGS in recipients with DM but not HTN or IMD. Etiology of ESRD does not appear to be a putative risk factor for outcomes with the use of single pediatric-donor kidneys. The increased risk of graft failure in EB recipients with DM, but not HTN or IMD, suggests an opportunity for risk stratification based on ESRD; however, further analyses are needed.

Clinical Prediction Models of Patient and Graft Survival in Kidney Transplant Recipients: A Systematic Review.

Clinical Prediction Models of Patient and Graft Survival in Kidney Transplant Recipients: A Systematic Review.

Aneurisma umeral em doentes com transplante renal

In patients with end-stage chronic kidney disease, brachial artery aneurysms proximal to an arteriovenous fistula are a rare and late complication. The aim of this study was clinical and demographic characterization of these patients and analysis of the outcomes of surgical treatment.An observational retrospective study was conducted comprising a period of 10 years (2002-2012) on receivers of kidney transplant with brachial artery aneurysms in limbs with a previously constructed radiocephalic fistula. Patients with access-related pseudo-aneurysms were excluded.Six patients – 5 male (83%) and 1 female (17%) – with an average age of 54 years, all of whom were kidney transplant recipients and had a ligated/occluded radio-cephalic fistula. The most common presentation was a painless pulsatile mass. Average aneurysm diameter was 32.5mm. All patients had their aneurysm resected. An interposition graft was placed in 5 patients - vein graft in 4 patients, prosthetic graft in 1 patient. End-to-end anastomosis was performed in 1 patient. The average follow-up was 35 months, with thrombosis of 1 prosthetic graft at 2 months, 2 patients suffered aneurysmal degeneration (33%) of the graft and/or brachial artery proximal to the reconstruction at 53 and 60 months, all requiring a second procedure. No fatalities or cases of limb loss were recorded.Expansive remodeling caused by high flow and shear stress proximal to an arteriovenous fistula associated with longer survival of kidney transplant recipients and the effect of immunosuppressive therapy may explain development of these aneurysms. Our results point out that venous conduit should be the preferred choice by its longer patency, although requiring a non-invasive surveillance program by the risk of late aneurysmal degeneration.

919 Cancer screening can improve overall and cancer-specific survival in kidney transplant recipients

919 Cancer screening can improve overall and cancer-specific survival in kidney transplant recipients

Improved survival in kidney transplant recipients

Improved survival in kidney transplant recipients

Meta-analysis of single-arm survival studies: a distribution-free approach for estimating summary survival curves with random effects

In epidemiologic studies and clinical trials with time-dependent outcome (for instance death or disease progression), survival curves are used to describe the risk of the event over time. In meta-analyses of studies reporting a survival curve, the most informative finding is a summary survival curve. In this paper, we propose a method to obtain a distribution-free summary survival curve by expanding the product-limit estimator of survival for aggregated survival data. The extension of DerSimonian and Laird's methodology for multiple outcomes is applied to account for the between-study heterogeneity. Statistics I(2) and H(2) are used to quantify the impact of the heterogeneity in the published survival curves. A statistical test for between-strata comparison is proposed, with the aim to explore study-level factors potentially associated with survival. The performance of the proposed approach is evaluated in a simulation study. Our approach is also applied to synthesize the survival of untreated patients with hepatocellular carcinoma from aggregate data of 27 studies and synthesize the graft survival of kidney transplant recipients from individual data from six hospitals.

Efficacy and safety of febuxostat in the treatment of hyperuricemia in stable kidney transplant recipients

BackgroundPost-transplant hyperuricemia (PTHU), defined as serum uric acid concentration ≥7.0 mg/dL or need for treatment with allopurinol or benzbromarone, reduces long-term allograft survival in kidney transplant recipients. Febuxostat, a new nonpurine selective xanthine oxidase inhibitor, is well tolerated in patients with moderate renal impairment. However, its efficacy and safety in kidney recipients with PTHU is unclear. We therefore assessed the efficacy and safety of febuxostat in stable kidney transplant recipients with PTHU.MethodsOf 93 stable adult kidney transplant recipients, 51 were diagnosed with PTHU (PTHU group) and 42 were not (NPTHU group). Of the 51 patients with PTHU, 26 were treated with febuxostat (FX group) and 25 were not (NFX group), at the discretion of each attending physician. One-year changes in serum uric acid concentrations, rates of achievement of target uric acid (<6.0 mg/dL), estimated glomerular filtration rates in allografts, and adverse events were retrospectively analyzed in the FX, NFX, and NPTHU groups.ResultsThe FX group showed significantly greater decreases in serum uric acid (−2.0±1.1 mg/dL versus 0.0±0.8 mg/dL per year, P<0.01) and tended to show a higher rate of achieving target uric acid levels (50% versus 24%; odds ratio 3.17 [95% confidence interval 0.96–10.5], P=0.08) than the NFX group. Although baseline allograft estimated glomerular filtration rates tended to be lower in the FX group than in the NFX group (40±14 mL/min/1.73 m2 versus 47±19 mL/min/1.73 m2), changes in allograft estimated glomerular filtration rate were similar (+1.0±4.9 mL/min/1.73 m2 versus −0.2±6.9 mL/min/1.73 m2 per year, P=0.50). None of the patients in the FX group experienced any severe adverse effects, such as pancytopenia or attacks of gout, throughout the entire study period. Nephrologists were more likely than urologists to start febuxostat in kidney transplant recipients with PTHU (69% versus 8%).ConclusionTreatment with febuxostat sufficiently lowered uric acid levels without severe adverse effects in stable kidney transplant recipients with PTHU.

A Case of Infective Endocarditis with Cytomegalovirus Infection after Kidney Transplantation

Advances in immunosuppressive therapy have increased the survival of kidney transplant recipients, yet suppression of the immune system after transplantation can promote infectious complications. Cytomegalovirus (CMV) infection remains one of the most important complications following kidney transplantation and it is a risk factor for developing superinfections with other organisms. Aspergillus endocarditis is a rare life‐threatening complication in kidney transplantation. Coinfection of CMV and Aspergillus endocarditis is rare worldwide and has not been reported in Korea. We report a case of Aspergillus endocarditis that developed in a patient with CMV infection after kidney transplantation. His clinical condition did not improve despite mitral valve replacement and empirical antibiotic treatment, but he was eventually treated successfully with antifungal agents for 6 weeks. (Korean J Med 2014;86:627-631)

Survival of living donor renal transplant recipients in Sri Lanka: a single-center study.

Chronic kidney disease is one of the main public health concerns in Sri Lanka. In comparison with dialysis, successful kidney transplantation improves both patient survival and quality of life, relieves the burden of dialysis in patients suffering from end-stage renal disease and decreases the cost of healthcare to the society and government. The objective of this retrospective cohort study was to evaluate graft and patient survival rates in patients who were transplanted from living donors at the Nephrology Unit of the National Hospital of Sri Lanka from January 2005 to January 2011. Data were collected using an interviewer-administered questionnaire and through a review of past medical records. The Kaplan-Meier method was used to determine the survival rate, the log rank test was used to compare survival curves and the Cox proportional hazard model was used for multivariate analysis. Mean follow-up was 26.44±16.6 months. The five-year death-censored graft survival of kidney transplant recipients from living donors in our center was 93.5% and the five-year patient survival was 82.2%, which is comparable with other transplant programs around the world. The number of acute rejection episodes was an independent risk factor for graft survival. Delayed graft function, younger recipient age and unknown cause of end-stage renal disease were found to be risk factors for graft failure but after adjusting for confounding factors, and the difference was not apparent.

Prognostic ROC Curves

Survival curves are a popular tool for representing the association between a binary marker and the risk of an event. The separation between the survival curves in patients with a positive marker (high-risk group) and a negative marker (low-risk group) reflects the prognostic ability of the marker. In this article, we propose an alternative graphical approach to represent the discriminative capacity of the marker-a receiver operating characteristic (ROC) curve, tentatively named prognostic ROC curve-obtained by plotting 1 minus the survival in the high-risk group against 1 minus the survival in the low-risk group. The area under the curve corresponds to the probability that a patient in the low-risk group has a longer lifetime than a patient in the high-risk group. The prognostic ROC curve provides complementary information compared with survival curves. However, when the survival functions do not reach 0, the prognostic ROC curve is incomplete. We show how a range of possible values for the area under the curve can be derived in this situation. A simulation study is performed to analyze the accuracy of this methodology, which is also illustrated by applications to the survival of patients with brain metastases and survival of kidney transplant recipients.

Extrarenal Factors Influencing Resistance Index in Stable Kidney Transplant Recipients

Increased intrarenal resistance index (RI) has been associated with decreased long-term allograft and patient survival in kidney transplant recipients. Taking into account the potential role of endothelial dysfunction, systemic inflammation, arteriosclerotic lesions, and left ventricle remodeling, we performed a cross-sectional study that aimed to evaluate extrarenal factors that may have influence on kidney graft RI in a large cohort of stable kidney transplant recipients. One hundred seventy-four kidney transplant recipients were enrolled into the study. Mean time after transplantation was 8.4±1.8 years. Echocardiography, carotid ultrasound (intima-media thickness), pulse wave velocity, and Doppler examination of kidney graft were performed. The inflammatory markers, adhesion molecules, and plasma N-terminal prohormone of brain natriuretic peptide concentrations were also measured. Patients were divided into quartile subgroups based on RI value (Q1: RI≤0.68, Q2: RI=0.69-0.72, Q3: RI=0.73-0.76, and Q4: RI≥0.77). The analyzed subgroups were comparable with respect to demographics (except age) and anthropometric parameters as well as comorbidities. The values of age, serum phosphate, pulse wave velocity, left ventricular mass (LVM), and LVM index (LVMI) increased in subsequent RI quartile subgroups. The strongest correlation was found between RI and age, LVM, LVMI, and plasma parathormone concentration and was negative with estimated glomerular filtration rate. In backward stepwise multivariate regression analysis, the RI variability was explained by age, LVMI, and serum phosphate concentration. Arterial stiffness and left ventricular hypertrophy may significantly influence the intrarenal vascular resistance measured using Doppler sonography in stable kidney transplant recipients.

Changes in Biomarkers Associated with Living Kidney Donation

Living donor kidneys have been associated with better graft and overall survival in kidney transplant recipients. Although a living kidney donation is generally considered safe in carefully selected living donors, concerns of possible adverse effects related to kidney donation remain, especially in younger and high-risk donors. In this study, we examined the changes in a panel of traditional and novel serum biomarkers linked with cardiovascular conditions in a cohort of 34 healthy living kidney donors with a mean age ± SD of 40 ± 10 years and estimated predonation glomerular filtration rate (GFR) of 86 ± 10 ml/min/1.73 m². At 6 months after donation, there were no significant changes in the clinical parameters including body mass index and blood pressure despite a significant decline in the mean estimated GFR to 60 ml/min/1.73 m². Among the panel of markers, the levels of symmetric dimethylarginine and fibroblast growth factor 23 increased significantly compared to baseline, suggesting that living kidney donation may result in changes in biomarkers that are associated with cardiovascular risk in other cohorts.

P23 CBS gene variants are associated with conditions characterized by ischemia

The CBS gene regulates the expression of cystathionine beta-synthase (CBS), a key enzyme in the production of hydrogen sulfide (H 2 S) by conversion of homocysteine (Hcy). H 2 S is a gasotransmitter that protects cells against ischemic damage by exerting vasodilatory, anti-inflammatory and antioxidant effects. Both renal transplantation and preeclampsia (PE) are conditions marked by ischemia. Renal ischemia/reperfusion impairs CBS activity and consequently H 2 S production. Partial restoration of CBS activity causes an increase in H 2 S levels and a reduction of ischemia/reperfusion damage. Also, H 2 S is involved in placental vascular tone regulation. Furthermore, preeclamptic women have hyperhomocysteinemia and a decreased placental expression of the CBS gene. We therefore hypothesize that variations in the CBS gene caused by single nucleotide polymorphisms (SNPs) affect both susceptibility to ischemic damage in renal transplantation and the onset of PE. The genotype of 1271 renal transplantation donor and recipient pairs in the University Medical Centre Groningen were determined for seven tag SNPs in the CBS locus. These SNPs were analyzed for association with primary non-function (PNF), delayed graft function, first years biopsy proven acute rejection, death-censored graft survival and patient survival. In the Oslo University Hospital, 99 controls and 60 severe and 39 mild cases of PE were genotyped for six of these seven tag SNPs. Severe and mild cases of PE were subdivided into early- (<34 weeks) and late-onset (>34 weeks of pregnancy). The SNPs were then analyzed for association with the onset of PE. Univariate analysis showed improved graft survival in kidney transplant recipients that homozygously carry the minor allele of rs11203172 (HR[95%CI] = 0.124[0.017–0.882], p = 0.013 (homozygous carriers of the minor allele versus others)). Furthermore, no PNF was seen in these patients. Multivariate analyses showed no significant associations, most probably due to the relatively low number of patients in this group and the number of parameters studied. Univariate analysis also showed patients carrying the minor allele of rs11203172 to have a reduced risk to develop severe PE (OR[95%CI] = 0.54[0.21–0.94], p = 0.023). Conversely, the minor allele of rs234706, which is known to be associated with low Hcy, increased the risk to develop mild, late-onset PE (2.10[1.15–3.85], p = 0.016). SNPs in the CBS gene are associated with both kidney graft survival and the risk to develop PE. Changes of the function or expression of CBS caused by SNPs may affect ischemic conditions through decreased H 2 S production or Hcy accumulation. Since CBS is markedly reduced under ischemic conditions we assume that these findings are of considerable importance. Further characterization of the effects of these CBS gene variants and their alleged role in ischemia is warranted.

Survival of Renal Transplantation Patients Older Than 60 Years: A Single-Center Experience

BackgroundElderly patients are the fastest growing population requiring renal replacement therapy. It has been stated that renal transplantation may be the best treatment option for these patients. However, it has been observed that older patients have a higher mortality rate than those who are younger. Yet the factors that determine post-transplantation outcomes in this population remain poorly defined. The aims of this study were to evaluate the graft and patient survival in kidney transplant recipients who are older than 60 years of age to identify relevant predictive factors. MethodsIn this population-based retrospective cohort study of 201 kidney transplantations performed in elderly patients from January 2002 throughout June 2009, we estimated the 1-,3-,and 5-year patients and graft survival rates. We also evaluated the complications and the predictors of poor outcomes. Survival times were analyzed using the Kaplan–Meier method and survival differences assessed with Mantel-Cox log rank-test. We performed a Cox proportional hazards regression models to evaluate the impact of baseline and treatment characteristics on patient and graft survival. ResultsGraft and patient survival rates at 1, 3, and 5 years were 76.4%, 71.3%, and 54.3%, and 78.2%, 73.8%, and 56.4%, respectively. Graft survival rates censored for patient death with a functioning graft were 93.1, 92.1, and 89%. Patient survival rates differed between diabetic and nondiabetic subjects at 1, 3 and 5 years (69.5% versus 83.6%; 59.8% versus 72.3%; 43.6% versus 65.7%; P = .008). On multivariate analysis, the factors associated with patients survival were diabetes mellitus (hazard ratio [HR] 2.058, 95% confidence interval [CI] 1.173–3.611, P = .012) and the 1-month serum creatinine value was > 1.6 mg/dL (HR 2.108 for each point increase, 95% CI 1.521–2.921, P = .000). Furthermore, there was an insignificant trend forward an association between active or past smoker and lower patient survival (HR 1.689, 95% CI 0.937–3.043, P = .08). The main causes of graft loss were patient death (79.5%). acute rejection (6.8%), and chronic allograft nephropathy (5.5%). ConclusionRenal transplantation can be performed safely and with acceptable outcomes in elderly patients after appropriate clinical evaluation. The grafts show excellent survival albeit that deaths with a functional graft continue to be an important issue.

Model Comparisons of Competing Risk and Recurrent Events for Graft Failure in Renal Transplant Recipients

Risk factor analysis of long-term graft survival in kidney transplant recipients is usually based on Cox regression models of time to first occurrence of doubling of serum creatinine or graft loss (DSCGL). However, death is a competing cause of failure, and censoring patients who die could bias estimates. We therefore compared estimates of time to first event versus estimates that included death as a competing risk and recurrent events. A Cox regression analysis of 1997-2002 data from the Assessment of Lescol in Renal Transplant (ALERT) trial population identified an eight-factor risk model, by analyzing time to first occurrence of DSCGL. The same factors were re-analyzed, allowing for death as competing. The probability of survival free of DSCGL was estimated; and two recurrent models (marginal and conditional) were used for time to events. Creatinine, systolic BP, and HLA-DR mismatches lost 33%-46% of their strength of association with DSCGL when death was included as a competing risk. Small changes were observed if recurrent events were analyzed in the marginal model. The relationship between serum creatinine and DSCGL was attenuated when death was considered as a competing risk; inclusion of recurrent events had little effect. These findings have important implications for analysis and trial design in populations at high mortality risk.