Predictive Factors in Chronic Allograft Nephropathy

Role of the IL-33/ST2 pathway in renal allograft rejection

The interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) pathway modulates immune response and inflammation, associated with allograft dysfunction and rejection. We hypothesized that IL-33/ST2 is a marker of renal allograft rejection and IL-33/ST2 expression may differ according to rejection type. IL-33/ST2 expression was measured in sera and kidney tissues from recipients with acute antibody-mediated rejection (AAMR), acute cell-mediated rejection (ACMR), chronic antibody-mediated rejection (CAMR), and healthy controls. The soluble ST2 and IL-33/ST2 expression levels were higher in participants with all three rejection types than in controls. Although the expression levels in recipients with AAMR and ACMR were significantly higher than those with CAMR, there was no significant difference between the expression levels in AAMR and ACMR. Although IL-33, IL-8, and fibronectin expression were significantly increased after the addition of the recipients' serum in primary cultured human renal proximal tubular epithelial cells, the levels decreased after treatment with an anti-ST2 antibody. Furthermore, the anti-ST2 antibody specifically suppressed the upregulation of the mixed lymphocyte reaction. Boyden chamber assays demonstrated that anti-ST2 antibody abrogated chemotaxis induced by recombinant IL-33. Thus, IL-33 and ST2 are potent mediators of rejection. Treatment with an anti-ST2 antibody ameliorates rejection and could be a potential therapeutic strategy for renal allograft rejection.

Body Shape Index Predicts Metabolic Syndrome and Insulin Resistance in Renal Transplant Recipients

Obesity is one of the most important metabolic diseases around the world. There are no reliable and inexpensive methods to evaluate obesity. All of the anthropometric measurements used have some limitations. In 2012, Krakauer et al developed a new method, called A Body Shape Index (ABSI), to identify abdominal obesity that is derived from weight, height, and waist circumference. In this study, we aimed to investigate the clinical usefulness of the ABSI to predict the presence of insulin resistance (IR) and metabolic syndrome (MetS) in renal transplant recipients. A total of 155 patients were included in the study. Prevalence of IR was 17.4%, and MetS was 62.6%. ROC results demonstrated the power of all anthropometric indices to discriminate patients with and without MetS and IR in the renal transplant populations. ROC curves showed that waist-to-height ratio (WHtR) had the optimal power to discriminate MetS and IR in women. WC had higher area under curve than all other anthropometric indices to predict MetS and IR in men. WC in men and WHtR in women has higher discriminatory capacity to predict MetS and IR in renal transplant recipients. An obvious difference was observed in the optimal anthropometric measures between the 2 sexes, suggesting that sex-specific measures should be used in practice. In order to evaluate the value of ABSI in determining metabolic risk factors, studies with larger, randomized, controlled body fat ratios are needed.

Correlation Between Renal Cortical Stiffness and Histological Determinants by Point Shear-Wave Elastography in Patients With Kidney Transplantation

INTRODUCTION

Renal allograft biopsy is the gold standard for the detection of histological lesions of chronic allograft dysfunction. The identification of a noninvasive routine test would be desirable. Elastosonography is used to assess tissue stiffness according to viscosity, and no data are available on the use of point quantification shear-wave elastography (ElastPQ) for the evaluation of renal chronic lesions.

RESEARCH QUESTION

To evaluate the feasibility of ElastPQ to assess cortical allograft stiffness and to determine the correlation of clinical, biological, and pathological factors with the diagnostic accuracy of kidney stiffness values in patients with histological lesions.

DESIGN

Forty-two patients underwent kidney transplant biopsy and 10 valid measurements of ElastPQ, blindly performed by 2 operators. The interobserver reproducibility was assessed according to intraclass correlation coefficient. The ElastPQ measurements and the clinical data were compared using the Spearman correlation analysis.

RESULTS

97.6% reliable measurements were obtained using ElastPQ, with an excellent interobserver agreement. The kidney stiffness was significantly higher in the patients with a time since transplantation >12 months and was correlated with chronic lesions (interstitial fibrosis, tubular atrophy transplant glomerulopathy, and mesangial matrix), with the interstitial fibrosis/tubular atrophy, score and with the sum of the scores of the chronic lesions. Mesangial matrix increase is the only independent determinant of kidney stiffness.

DISCUSSION

ElastPQ is a noninvasive, reproducible, and sensitive diagnostic tool able to detect moderate/severe chronic lesions. Its routine use during follow-up can identify patients eligible for biopsy, which remains the gold standard exam for detecting chronic allograft dysfunction.

Neutrophil Gelatinase-Associated Lipocalin as a Biomarker of Allograft Function After Renal Transplantation: Evaluation of the Current Status and Future Insights

Neutrophil gelatinase‐associated lipocalin (NGAL), a protein belonging to the lipocalin superfamily initially found in activated neutrophils, is expressed by several cell types, including kidney tubule. The increase in NGAL production and release from tubular cells in response to various insults has been proven to predict acute kidney injury (AKI). For this reason, it has emerged as a valuable noninvasive biomarker of AKI in clinical nephrology. Also in the renal transplant setting, different studies have indicated NGAL as a valuable tool, especially in the early postoperative period, since the currently available clinical and laboratory parameters remain poorly sensitive to monitor immediate posttransplant graft function. This is an analysis of the recent literature to assess the utility of plasma and urinary NGAL, exosomal mRNA for NGAL, and NGAL levels in the perfusate of machine‐perfused kidneys for the prediction of graft function recovery in the early postsurgery phase after renal transplantation. We found that NGAL appears as a promising troponin‐like biomarker to detect short‐term impairment of graft function after renal transplant, but there are still some limitations in its clinical application, essentially related to its low specificity. Moreover, comparing NGAL assayed in serum, urine, machine‐perfusate, or as exosomal mRNA, each one has shown limitations and benefits in terms of predictive performance for DGF, according to various existing studies, feasibly due to different cut‐off levels, designs and patient sample sizes.

Fibroblast Growth Factor 23: Mineral Metabolism and Beyond

Patients affected by chronic kidney disease (CKD) exhibit a high risk of cardiovascular mortality that is poorly explained by traditional risk factors. There is a growing awareness about the role of derangement of mineral metabolism that is currently accepted as a trigger and sustainer of cardiovascular disease (CVD) in CKD patients. The synthetic definition of CKD mineral and bone disorder (CKD-MBD) split the concept that the indexes of mineral metabolism extend their effects beyond the bone until the vascular wall and metabolic milieu of CKD patients through complex pathways. A better understanding of the biomarkers and mechanisms of left ventricular hypertrophy, CVD, inflammation, and chronic renal damage may help with the diagnosis and treatment of the systemic impairment that occurs secondary to CKD-MBD, thus slowing the progression of renal and CVD and improving patient survival. Recent insights into fibroblast growth factor (FGF) 23 have led to marked advancement in interpreting data on CVD and CKD progression ascribing to FGF23 a pivotal role in these pathologies independent of its co-receptor klotho and well beyond mineral metabolism. This review article will discuss the current experimental and clinical evidence regarding the role of FGF23 in physiology and pathophysiology of CKD and its associated complications with an emphasis on CVD.

Identification of expanded T-cell clones by spectratyping in nonfunctioning kidney transplants

Background

The aim of this study was the application of complementarity-determining region-3 spectratyping analysis to determine T-cell-repertoire complexity and to detect T-cell-clone expansion, as a measure of immune response in nonfunctioning kidney transplants (group hemodialysis-transplant [HD-Tx]), nontransplanted dialysis patients (group hemodialysis [HD]), and normal subjects as controls (group C).

Patients and methods

Analysis of T-cell receptor (TCR) diversity by spectratyping was applied to peripheral blood samples collected from 21 subjects: eight in group HD-Tx, seven in group HD, and six in group C.

Results

Considering the extent of the skew in TCR variable region repertoires as a measure of clonal T cells, we found that the number of altered spectra showed a progressive increase from normal subjects to dialysis patients and to nonfunctioning kidney transplants, respectively. Healthy subjects had the lowest number of altered spectra, and patients with nonfunctioning kidney transplants the highest. Differences were significant for group HD-Tx vs group C (P=0.017) and group HD vs group C (P=0.015), but not between nonfunctioning kidney-transplant recipients and dialysis patients (group HD-Tx vs group HD).

Conclusion

Although dialysis appears to be a weaker trigger for clonal expansion of T cells, our data suggest that the utilization of complementarity-determining region-3 spectratyping analysis of the TCR repertoire might be useful to monitor specific immunoactivation in patients before and after kidney transplantation.

Seroprevalence of a "new" bacterium, Simkania negevensis, in renal transplant recipients and in hemodialysis patients

Background

Simkania negevensis is an obligate intracellular bacterium belonging to the family Simkaniaceae in the Chlamydiales order. It is considered an ubiquitous microorganism and aquatic environments may be involved as a source of infection for humans. It was just isolated in samples from domestic water supplies and from mains water supplies, like spa water or swimming pool water, confirming its ability to resist to the common chlorination treatments. Evidence indicates a possible role of the microorganism in respiratory tract infections, in gastroenteric disorders and in the pathogenesis of cardiovascular disease, furthermore it has hypothesized that it could play a role in lung transplant rejection. Prevalence and possible effects in nephrology are unknown.

Methods

We examined the occurrence of Simkania negevensis in two differents populations, both characterized by a high susceptibility to infectious complications: 105 hemodialysis patients, 105 renal transplant recipients and 105 healthy subjects through the IgG and IgA response to Simkania negevensis in their sera. Serum antibodies to Simkania negevensis were detected by a homemade ELISA performed according to the Kahane’s protocol. Furthermore water samples from hemodialytic circuit were collected, to evaluate Simkania negevensis resistance to usual treatment of disinfection.

Results

Our results were unexpected, showing a higher seroprevalence of antibodies against Simkania negevensis in the hemodialysis patients, compared to renal transplant patients (IgG 22% vs 9% - IgA 9% vs 3%). S. negevensis was isolated in all water samples analyzed.

Conclusions

Our study detected for the first time the occurrence of S. negevensis in hemodialysis and in renal transplant patients. Our findings suggest that water used in hemodialysis could be one of the possible sources of S. negevensis infection, without clinical involvement risk for patients.

Ganciclovir-Resistant Cytomegalovirus Infection in a Kidney Transplant Recipient Successfully Treated with Foscarnet and Everolimus

Cytomegalovirus (CMV) infection remains a major cause of morbidity, graft failure, and death in kidney transplant recipients. We describe a case of a 53-year-old CMV-seronegative man who underwent renal transplant from a CMV-positive donor and who developed ganciclovir- (GCV-) resistant CMV infection. Foscarnet was started while immunosuppressive therapy was modified with the introduction of everolimus minimizing tacrolimus dosage. Only two weeks after the start of this treatment regimen was the patient's viral load negative. At two-year follow-up the patient has no clinical or laboratory signs of CMV infection and a good and stable renal function or graft survival. In our case, administration of an mTOR inhibitor combined with foscarnet led to rapid and persistent viral clearance without compromising short- and medium-term graft function. This combination therapy supports the need for the kidney transplant community to individualize a target therapy for each type of GCV-resistant CMV infection.

Renal transplantation parenchymal complications: what Doppler ultrasound can and cannot do

Kidney transplantation is the treatment of choice in end-stage renal disease, given the better quality of life of transplanted patients when compared with patients on maintenance dialysis. In spite of surgical improvements and new immunosuppressive regimens, parts of transplanted grafts still develop chronic dysfunction. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of vascular and surgical complications of the transplanted kidney, its role is not fully understood in case of parenchymal complications of the graft. The specificity of Doppler is low both in case of acute complications, such as acute tubular necrosis, drugs toxicity and acute rejection, and in case of chronic conditions, such as chronic allograft nephropathy. Single determinations of resistance indices present low diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques such as tissue pulsatility index, maximal fractional area and contrast-enhanced ultrasound increase ultrasonography diagnostic power in case of parenchymal complications of the transplanted kidney.

Predictive biomarkers of renal allograft failure

BACKGROUND

Survival of renal allografts is limited by chronic allograft deterioration resulting from processes that are difficult to detect in their early stages, when therapeutic interventions would be most effective. Predictive biomarkers from easily accessible specimens, such as blood or urine, might improve early diagnosis of smoldering graft-damaging processes and help with the identification of patients at particularly high risk of sustained injury, thereby helping to tailor therapy and appropriate follow-up screening.

OBJECTIVE

This article reviews recently investigated biomarkers for the prediction of renal allograft failure, outlines the new '-omic' technologies as a potential source for the identification of new predictive biomarkers and judges the practical value of predictive biomarkers at the present timepoint.

METHODS

A literature search was performed using the medical database PubMed. No general restrictions (e.g., year of publication) were applied, but the focus was set on more recently published articles.

CONCLUSION

Despite a large number of interesting studies, none of the investigated candidate biomarkers is robustly established for widespread clinical use or able to replace biopsies for graft assessment.

Factors increasing quantitative interstitial fibrosis from 0 hr to 1 year in living kidney transplant patients receiving tacrolimus

BACKGROUND

This study investigated the increase in interstitial fibrosis (IF) from 0 hr to 1 month and 1 year posttransplantation in biopsy sections and assessed the risk of developing IF in 118 living kidney recipients.

METHODS

A quantitative analysis of IF was performed using computer-assisted imaging. The percent IF (%IF) in the cortical region at 0 hr was defined as the baseline, and the increases in %IF at 1 month and 1 year were calculated. Demographics, higher (regimen 1) and lower (regimen 2) target trough concentrations of tacrolimus, and the cytochrome P450 (CYP) 3A5 polymorphism were tested as risk factors.

RESULTS

The mean %IF at 0 hr, 1 month, and 1 year was 10.3%+/-4.2%, 15.0%+/-5.8%, and 19.0%+/-7.7%, respectively. %IF increased 1.7- and 2.2-fold from 0 hr to 1 month and 1 year posttransplantation, respectively. At 1 year, the increase was higher in patients with the CYP3A5*3/*3 genotype (nonexpressers), those treated with regimen 1, and those with a lower estimated glomerular filtration rate and higher body mass index. In a multivariate analysis, CYP3A5 nonexpression correlated with the development of IF (odds ratio 2.63, P=0.018). Tacrolimus blood levels in the early stage posttransplantation were higher in nonexpressers than CYP3A5 expressers in both regimens 1 and 2, despite therapeutic drug monitoring.

CONCLUSIONS

The higher concentrations of tacrolimus, especially in the nonexpressers treated with regimen 1, might influence the development of IF. This study suggested that a new regimen with lower and narrow target trough levels of tacrolimus or a dosing strategy based on the CYP3A5 genotype is needed to reduce the risk of developing IF.

Association between Toll-like receptors 4 and 2 gene polymorphisms with chronic allograft nephropathy in Turkish children

Toll-like receptor (TLR) gene polymorphism is known to impair intracellular signaling pathways following adaptive immune responses. Our aim was to investigate the distribution of TLR4 and TLR2 gene polymorphisms among pediatric renal transplantation patients in relation to chronic allograft nephropathy (CAN). In addition to 115 healthy controls, we included 69 renal recipients, 19 of whom were identified as CAN by biopsy scored according to the Banff criteria. Polymorphisms at TLR4 Asp299Gly and/or Thr399Ile were present in 11.6% of renal transplant recipients. None of these subjects was identified in cosegregation with the Thr399Ile allele, whereas three had an isolated Asp299Gly and five had an isolated Thr399Ile. Neither renal recipients nor healthy controls were homozygous for both Asp299Gly and Thr399Ile polymorphisms. However, TLR4 Thr399Ile polymorphism and Ile allele was greater among CAN (-) versus CAN (+) recipients (P > .05). The frequency of TLR2 mutant type Gln allele was significantly higher in recipients than among healthy controls (P < .0001). However, the Gln allele frequency was similar between CAN (+) and CAN (-) patients. The results of present study may be speculated to show TLR4 and TLR2 gene polymorphisms as protective factors from CAN development due to impaired immune responses.

Early assessment of renal resistance index and long-term renal function in renal transplant recipients

BACKGROUND

The effect of the intrarenal arterial resistance index (RI) on long-term renal functions is not well known. We examined the predictive value of intrarenal RI on long-term allograft outcomes.

METHODS

We retrospectively investigated 121 stable renal transplant recipients, followed for a mean of 63.21 +/- 19.9 months after renal transplant. Patients with complications during the first six months after transplant were not included. Color Doppler ultrasonography was done to calculate the intrarenal RI within the first four weeks after transplant.

RESULTS

Older recipient age, high pulse pressure, active smoking, and proteinuria were associated with a higher intrarenal RI. Multivariate analyses revealed that renal RI and donor age were independent predictors of allograft outcome. Kaplan-Meier estimates of cumulative graft survival were significantly worse in patients who had an RI of 0.7 or more than they were in patients who had an RI of less than 0.7 (p = .005). Development of chronic allograft nephropathy (CAN) was significantly higher in patients who had an RI of 0.7 or more (p = .02).

CONCLUSIONS

Renal RI determined within the first month after renal transplant predicts long-term allograft function and development of CAN in renal transplant recipients.

A randomized, prospective trial of rituximab for acute rejection in pediatric renal transplantation

We report 1-year outcomes of a randomized study of Rituximab versus standard-of-care immunosuppression (Thymoglobulin and/or pulse steroids) for treatment of biopsy confirmed, acute transplant rejection with B-cell infiltrates, in 20 consecutive recipients (2-23 years). Graft biopsies, with Banff and CADI scores, CD20 and C4d stains, were performed at rejection and 1 and 6 months later. Peripheral blood CMV, EBV and BK viral loads, graft function, DSA, immunoglobulins, serum humanized antichimeric antibody (HACA) and Rituximab, and lymphocyte counts were monitored until 1 year posttreatment. Rituximab infusions were given with a high index of safety without HACA development and increased infections complications. Rituximab therapy resulted in complete tissue B-cell depletion and rapid peripheral B-cell depletion. Peripheral CD19 cells recovered at a mean time of approximately 12 months. There were some benefits for the recovery of graft function (p = 0.026) and improvement of biopsy rejection scores at both the 1- (p = 0.0003) and 6-month (p < 0.0001) follow-up biopsies. Reappearance of C4d deposition was not seen on follow-up biopsies after Rituximab therapy, but was seen in 30% of control patients. There was no change in DSA in either group, independent of rejection resolution. This study reports safety and suggests further investigation of Rituximab as an adjunctive treatment for B-cell-mediated graft rejection.

The single insult of hypoxic preconditioning induces an antiapoptotic response in human proximal tubular cells, in vitro, across cold storage

OBJECTIVE

To examine whether hypoxia (one of the many components of ischaemic preconditioning) can induce a protective response in culture renal tubular cells, and thus determine if non-lethal periods of hypoxia could confer protection against apoptotic injury to human proximal tubular cells during cold storage and subsequent cytotoxic insult, and establish the cellular mechanisms by which this protection is induced.

MATERIALS AND METHODS

Human proximal tubular cells (HK-2) were pre-incubated for 24 h in normoxic or hypoxic conditions and then incubated at 4 degrees C for 6 h to mimic cold storage, before being returned to normal conditions and exposed to varying concentrations of cyclosporine A (CSA). Cell viability and apoptosis were measured using propidium iodide staining and flow cytometry. The expression of heat-shock protein (HSP)-70 was determined by Western blotting.

RESULTS

Hypoxia had no effect on cell viability or apoptosis. Pre-exposure of cells to hypoxia significantly protected against CSA-induced damage even after a period of cold storage. Western blotting analysis showed that hypoxia up-regulated the anti-apoptotic protein HSP-70. HK-2 cells over-expressing HSP-70 mimicked hypoxia preconditioning, in that they were protected during cold storage and CSA-induced apoptosis.

CONCLUSION

Exposure of renal tubular cells to a sequential model of cold storage, reperfusion and incubation with CSA resulted in apoptotic cell death. Preconditioning these cells with hypoxia induced a protective response and up-regulation of the anti-apoptotic protein HSP-70. There was a similar response in non-preconditioned cells over-expressing HSP-70. Further understanding of the cellular changes occurring during this period of preconditioning will allow the development of more targeted, clinically relevant methods of preconditioning in renal transplantation.

Association of cytokine polymorphisms with subclinical progressive chronic allograft nephropathy in Japanese renal transplant recipients: preliminary study

BACKGROUND

The present study calculated the risk of developing subclinical progressive chronic/sclerosing allograft nephropathy (CAN) under tacrolimus-based immunosuppression according to genetic polymorphisms of cytokines and growth factors, and clinical events including delayed graft function (DGF), acute rejection (AR) and cytomegalovirus (CMV) infection.

METHODS

The subjects were 50 recipients with stable graft function more than one year after renal transplantation. The criteria for subclinical progressive CAN were CAN grade 2 or 3 changes on Banff classification and stable serum creatinine (SCr) levels. Ten genetic polymorphisms were assessed.

RESULTS

Eleven patients (22.0%) developed progressive CAN. The mean ages and SCr levels of recipients with and without progressive CAN were 41.2 and 47.1 years, and 1.46 and 1.22 mg/dL, respectively. There were no significant differences in donor age, number of HLA mismatches, DGF or CMV infection. Although the rate of AR episode seemed to be greater in patients with subclinical progressive CAN, the difference did not reach significance (P = 0.093). The frequencies of the interleukin (IL)-2 T-330G TT genotype (P = 0.046) and IL-4 C-590T C allele (P = 0.092) were higher in patients with progressive CAN. In univariate analysis, the presence of IL-2 T-330G TT (OR 4.57, P = 0.044) was associated with CAN development.

CONCLUSION

The presence of IL-2 T-330G TT genotype may be a risk factor for CAN. Further studies with a large number of subjects and analyses of many cytokine polymorphisms would contribute to the ability to make prognostic determinations or tailor immunomodulatory regimens after renal transplantation.

Sequential quadruple immunosuppression including sirolimus in extended criteria and nonheartbeating donor kidney transplantation

The aim was to evaluate feasibility and safety of calcineurin inhibitor-free immunosuppression in high-risk donor kidney transplantation with sequential sirolimus introduction. Kidney transplant patients (n=76) with a donor aged >60 years, donor with acute renal failure, or a nonheartbeating donor were included. Immunosuppression consisted of antithymocyte globulin or basiliximab, mycophenolate mofetil, prednisone, and sequential introduction of sirolimus. One-year patient survival was 96.2% and 95.8%; graft survival was 94.2% and 91.7%; acute rejection rates were 21.2% and 12.4%; delayed graft function was 21.2% and 66.7%; and creatinine clearance was 58+/-20 mL/min and 56+/-21 mL/min for the brain-dead donor group and the nonheartbeating donor group, respectively. Most adverse events were infections, but also three lymphoceles, three urinary fistulas, three wound seromas. Sequential sirolimus introduction in high-risk donor kidney transplantation was found to lead to good patient and graft survival and incidence of acute rejection and delayed graft function.

Metabolic Syndrome After Kidney Transplantation

BACKGROUND

Metabolic syndrome (MS) includes some risk factors for development of diabetes and cardiovascular disease, obesity (BMI > 30), high triglycerides, low HDL cholesterol, hypertension and impaired glucose tolerance. Following the definition of the Adult Treatment Panel III criteria, a diagnosis of MS was established when 3 or more factors were present. In renal transplant patients MS has been reported to negatively influence both patient and graft survivals. The present study sought to verify the effect of MS among our cases.

METHODS

298 cadaveric renal transplant recipients operated between January 1, 1996 and December 31, 2001 with absence of diabetes before transplantation, stable renal function 1 year posttransplantation and at least 4 years follow up were retrospectively evaluated from the end of the first post-operative year.

RESULTS

50 patients out of 298 (16,7%) had MS at the beginning of the study, including 37 of them with 3 and 13 with 4 risk factors. Only one patient with MS died of cardiovascular disease. Graft failure was observed in 23.5% MS patients versus 9,7% patients without the Syndrome (p:n.s.) Only Creatinine and the incidence of Cardiovascular Diseases at 4 years were statistically higher in MS patients (P < .001).

CONCLUSIONS

These results suggested that MS is a risk factor for increasing CVD morbidity and decreased graft function, but early treatment of risk factors as soon as they become apparent can limit the adverse effects on patient and graft survival.

Erythropoietin treatment in the sixth posttransplant month as a prognostic factor for renal allograft survival

The purpose of this work was to assess the prognostic value of the need for erythropoietin (EPO) treatment at 6 months after transplantation. We retrospectively reviewed the outcomes of 143 consecutive cadaveric kidney transplants performed between January 2000 and April 2004, functioning at 6 months postransplantation. Patients were divided into two groups: group EPO6m (n = 24) received EPO treatment in the sixth month, and a control group (n = 119) did not receive EPO. Renal function deterioration (RFD) was considered to be a sustained decrease in creatinine clearance (CrCl) greater than 20% between the sixth month postransplant and the last visit. Mean follow-up was 38 +/- 16 months. The mean ages of the donor (57 +/- 9 vs 49 +/- 12 years; P = .001) and the recipient (59 +/- 12 vs 47 +/- 17 years; P = .000) were greater in the EPO6m group. Delayed graft function (83% vs 48%; P = .001) was more frequent in the EPO6m group. At 6 months after transplantation the EPO6m group showed lower hemoglobin (11.52 +/- 1.71 vs 13.32 +/- 1.69 g/dL; P = .000), higher serum creatinine (2.31 +/- 0.72 vs 1.65 +/- 0.53 mg/dL; P = .000), lower CrCl (33.53 +/- 10.83 vs 53.6 +/- 17.58 mL/min; P = .000), and similar proteinuria. RFD was more common in the EPO6m group (38% vs 10%; P = .026), with a different pattern of evolution of CrCl (-0.098 +/- 0.176 vs +0.093 +/- 0.396 mL/min/mo, P = .000). Multivariate analysis demonstrated that treatment with EPO at 6 months was the only predictor of RFD (RR 4.46; 1.58 to 12.58; P = .005). The need for EPO at 6 months postransplant was a good predictor of later renal allograft deterioration, more sensitive than serum creatinine or proteinuria.