Delayed graft function and chronic allograft nephropathy: diagnostic and prognostic role of neutrophil gelatinase-associated lipocalin.

CONTEXT: Available markers are not reliable parameters to early detect kidney injury in transplanted patients. OBJECTIVE: Examine neutrophil gelatinase associated lipocalin (NGAL) in early detection of delayed graft function (DGF) and as a long-term predictor of graft outcome. PATIENTS AND METHODS: NGAL was evaluated in 124 transplanted patients. RESULTS: Urinary NGAL levels were associated to a 10% (HR: 1.10; 95% CI: 1.04-1.25; p < 0.001) and 15% (HR: 1.15; 95% CI: 1.09-1.26; p < 0.001) increased risk of DGF and allograft nephropathy progression, respectively. CONCLUSION: NGAL reflects the entity of renal impairment in transplanted patients, representing a biomarker and an independent risk factor for DGF and chronic allograft nephropathy progression.

Long-Term Structural and Functional Myocardial Adaptations in Healthy Living Kidney Donors: A Pilot Study.

BACKGROUND AND AIMS: Compensatory renal hypertrophy following unilateral nephrectomy (UNX) occurs in the remaining kidney. However, the long-term cardiac adaptive process to UNX remains poorly defined in humans. Our goal was to characterize myocardial structure and function in living kidney donors (LKDs), approximately 12 years after UNX. METHODS AND RESULTS: Cardiac function and structure in 15 Italian LKDs, at least 5 years after UNX (median time from donation = 8.4 years) was investigated and compared to those of age and sex matched U.S. citizens healthy controls (n = 15). Standard and speckle tracking echocardiography (STE) was performed in both LKDs and controls. Plasma angiotensin II, aldosterone, atrial natriuretic peptide (ANP), N terminus pro B-type natriuretic peptide (NT-proBNP), cyclic guanylyl monophosphate (cGMP), and amino-terminal peptide of procollagen III (PIIINP) were also collected. Median follow-up was 11.9 years. In LKDs, LV geometry and function by STE were similar to controls, wall thickness and volumes were within normal limits also by CMR. In LKDs, CMR was negative for myocardial fibrosis, but apical rotation and LV torsion obtained by STE were impaired as compared to controls (21.4 ± 7.8 vs 32.7 ± 8.9 degrees, p = 0.04). Serum creatinine and PIIINP levels were increased [1.1 (0.9-1.3) mg/dL, and 5.8 (5.4-7.6)] µg/L, respectively), while urinary cGMP was reduced [270 (250-355) vs 581 (437-698) pmol/mL] in LKDs. No LKD developed cardiovascular or renal events during follow-up. CONCLUSIONS: Long-term kidney donors have no apparent structural myocardial abnormalities as assessed by contrast enhanced CMR. However, myocardial deformation of the apical segments, as well as apical rotation, and LV torsion are reduced. The concomitant increase in circulating PIIINP level is suggestive of fibrosis. Further studies, focused on US and EU patients are warranted to evaluate whether these early functional modifications will progress to a more compromised cardiac function and structure at a later time.

ISMETT: An International Collaboration on Organ Transplantation.

The Institute of the Mediterranean for Transplantation and High Specialty Therapies (ISMETT) is a multi-organ transplant and high specialty center located in Palermo, Italy and managed by the University of Pittsburgh Medical Center. Clinical transplant activity started in 1999 and, herein, we illustrate the outcomes achieved over the past 15 years. In total, ISMETT has performed 997 liver transplants (83.9% adults, 16.1% pediatrics) with a significant percentage of liver transplants from cadaver split livers (17%) and partial grafts from living donors (11.5%). Among liver transplant recipients, the overall five-year graft survival was 74.3% in the adult population and 79% in the pediatric population. ISMETT has also performed 419 kidney transplants in total: 211 from cadaveric donors (22 double), 176 from living donors, and 32 combined (19 with liver, 11 with pancreas, and 2 with heart). The 5-year renal graft survival was 82.2% (cadaveric donor) and 92.2% (living donor). More recently, in 2005, ISMETT started pancreas, lung, and heart transplant programs. In total, 16 pancreas transplants have been performed, of which 12 were simultaneous pancreas-kidney transplants, 1 was pancreas after kidney, and 3 were pancreas alone transplants. One pancreatic islet transplant was also performed in a patient who had already undergone kidney transplantation. Patient and pancreas graft survivals at 1 year were 86.7% and 73.3%, respectively, and 80% and 73.3% at five years (pancreas survival is defined as normoglycemia and insulin-independence). Lung transplant has been performed in 133 patients (116 double and 17 single lung). Eleven were pediatric (8% of all transplants). The 1-month, 1-year, and 5-year overall graft survivals were, 93.8%, 81.4%, and 75.6%, respectively. Heart transplantation has been performed in 133 adults (85% were male). Coronary artery disease and cardiomyopathy were the leading underlying heart disease diagnoses leading to transplant. Mechanical support (ventricular assist device or extracorporeal membrane oxygenation) as a bridge to transplant was used in 18% of the heart transplant cases. One-year heart graft survival was 83% and 5-year heart graft survival was 81%.

Apelin and copeptin: two opposite biomarkers associated with kidney function decline and cyst growth in autosomal dominant polycystic kidney disease.

Vasopressin (AVP) plays a detrimental role in autosomal dominant polycystic kidney disease (ADPKD). Copeptin represents a measurable substitute for circulating AVP whereas apelin counteracts AVP signaling. The aim of this study was to investigate the predictive value of apelin and copeptin for the progression of ADPKD disease. 52 ADPKD patients were enrolled and followed until the end of the observation period or the primary study endpoint was reached, defined by the combined outcome of decrease of glomerular filtration rate associated with a total renal volume increase. Receiver operating characteristics (ROC) analysis was employed for identifying the progression of renal disease and Kaplan-Meier curves assessed the renal survival. Adjusted risk estimates for progression endpoint and incident renal replacement therapy (RRT) were calculated using Cox proportional hazard regression analysis. ADPKD patients were characterized by lower apelin levels and higher copeptin levels when compared with healthy subjects. These biomarkers were strictly correlated with osmolality and markers of renal function. At ROC analysis, apelin and copeptin showed a very good diagnostic profile in identifying ADPKD progression. After the follow up of 24 months, 33 patients reached the endpoint. Cox proportional hazard regression analysis showed that apelin predicted renal disease progression and incident RRT independently of other potential confounders. Apelin is associated with kidney function decline in ADPKD, suggesting that it may be a new marker to predict kidney outcome.

Influence of CYP3A5 and ABCB1 gene polymorphisms and other factors on tacrolimus dosing in Caucasian liver and kidney transplant patients.

Tacrolimus is a substrate of cytochrome P4503A (CYP3A) enzymes as well as of the drug transporter ABCB1. We have investigated the possible influence of CYP3A5 and ABCB1 single nucleotide polymorphisms (SNPs) and other factors (e.g. albumin, hematocrit and steroids) on tacrolimus blood levels achieved in a population of Caucasian liver (n=51) and kidney (n=50) transplant recipients. At 1, 3 and 6 months after transplantation, tacrolimus doses (mg/kg/day) and trough blood levels (C0) were recorded and the weight-adjusted tacrolimus dosage (mg/kg/day) was calculated. Polymerase chain reaction followed by restriction fragment length polymorphism analysis was used for genotyping CYP3A5*1 and *3 [6986A>G] as well as ABCB1 at exons 21 [2677G>T/A] and 26 [3435C>T] in both liver transplant donors and recipients and in kidney transplant recipients. Of the 152 subjects studied, 84.9% showed a CYP3A5*3/*3 genotype. The total frequency of the allelic variant *3 was 93%. For the G2677T/A and C3435T polymorphisms the total frequencies of the allelic variants T/A and T were 44.7 and 46.7%, respectively. At 1, 3 and 6 months after transplantation the dose-adjusted C0 levels were significantly lower in patients with one copy of the *1 allele compared to those homozygous for the *3 allele. In the case of liver transplant patients the tacrolimus dose requirements were dominantly influenced by the polymorphisms of the CYP3A5 gene in the donors. With regard to the ABCB1 SNPs, in general they did not show any appreciable influence on tacrolimus dosing requirements; however, kidney transplant recipients carrying the 2677T/A allele required significantly higher daily tacrolimus doses than subjects homozygous for the wild-type allele. Identification of CYP3A5 single nucleotide polymorphisms prior to transplantation could contribute to evaluate the appropriate initial dosage of tacrolimus in the patients.

The prognostic value of renal biopsy in type 2 diabetes mellitus patients affected by diabetic glomerulosclerosis.

BACKGROUND: Although several studies have dealt with clinicopathological correlations in diabetic glomerulosclerosis (DGS), few have investigated the prognostic value of the renal biopsy. METHODS: One hundred and thirty-five type2 diabetes mellitus (DM) patients with bioptically proven DGS and a mean follow-up of 56.1 months were subdivided in 5 groups according to the outcome: 1) living with preserved renal function; 2) living with renal failure, not requiring dialysis; 3) living in dialysis; 4) dead in dialysis; 5) dead with preserved renal function. Duration of DM, creatininemia and proteinuria values at the time of biopsy and a histologic scoring (from 0 to 3) of 10 morphologic features were considered for statistical analysis. RESULTS: Statistically significant differences were observed in the distribution of the above mentioned parameters in the 5 groups with the exception of the duration of DM. The prognosis of DGS is poor: 79 patients needed dialysis and 60 died. Univariate analysis demonstrated the prognostic value of creatininemia (>or= 1.5 mg/dL), proteinuria (>or= 3 g/d) and histologic score (>or= 10) in assessing the relative risk of progression to dialysis (OR= 9.75, 4.12 and 11 respectively). The prognostic value of the histologic score (or= 2) was maintained when each morphologic parameter was separately evaluated (OR ranging from 2.8 to 8.5). Multivariate analysis was applied and only serum creatinine and histological score maintained their statistical significance (OR=4.45 and 2.46). The independence of these two variables means that the risk of progression to dialysis is multiplied in each single patient. CONCLUSIONS: Renal biopsy adds reliable information to that supplied by clinical and laboratory findings in DGS and therefore its extensive adoption should be recommended. Thanks to the prognostic value of the single morphologic parameters, also small tissue samples can give reliable results.

Hepatitis C virus-related cryoglobulinemic glomerulonephritis: long-term remission after antiviral therapy.

BACKGROUND: Renal involvement in patients with hepatitis C virus (HCV) infection commonly manifests as cryoglobulinemic glomerulonephritis (CGN). The combination of interferon-alpha (IFN-alpha) and ribavirin, which is currently considered the standard antiviral therapy in chronic hepatitis C, could be difficult to carry out in cryoglobulinemic patients who are frequently anemic, even in the absence of renal failure. Clinical and histologic long-term results of this therapeutic regimen have not been so far reported in patients with CGN. METHODS: Three patients with HCV-related CGN and slightly impaired kidney function were treated with IFN-alpha and ribavirin for 12 months, and subsequently were followed up for 24 to 36 months. Two of these patients who were anemic were pretreated with erythropoietin (EPO). In each patient renal biopsy was performed before starting therapy and repeated 14 to 26 months after the end of treatment. RESULTS: In all three patients, antiviral therapy induced sustained virologic response, which was followed by clear improvement in clinical, biochemical, immunologic, and histologic features. Clinical and biochemical improvement steadily progressed in all three patients, achieving normal or nearly normal results at the end of follow-up. In contrast, some immunologic features, such as serum levels of C4 and rheumatoid factor activity, did not normalize in two and three patients, respectively. Posttreatment renal biopsies showed mildly active histologic lesions. CONCLUSION: Antiviral therapy with IFN-alpha and ribavirin may be considerably beneficial in patients with HCV-related CGN who obtain sustained virologic response.

How glomerular extracapillary proliferation might lead to loss of renal function: light microscopic and immunohistochemical investigation.

Although there has been extensive research into the mechanisms involved in glomerular crescent formation, it is not yet fully understood how this change may cause renal function impairment. The aim of this study is to identify morphologic changes which may be responsible for this phenomenon. Thirty-eight renal biopsies showing glomerulonephritis with extracapillary proliferation (20 vasculitis-related, 6 idiopathic, 9 due to immune-complex deposition and 3 superimposed on diabetic nephropathy) were considered, and 146 glomeruli in which both crescents and the urinary pole were found at the same time, were studied. The involvement of the urinary pole by cellular crescents was observed in 93.1 and 100% of the glomeruli with segmental or circumferential crescents, respectively. A tridimensional study, for the evaluation of the glomeruli as a whole, was performed on 8 biopsies by means of the step-section technique and disclosed the involvement of the urinary space and a close contact between crescent and tubular cells in all 54 investigated glomeruli. The reported features do not seem to be related to the type of cells which formed the crescent. Indeed, as shown by immunohistochemical study on 10 cases with anti-cytokeratin and anti-CD68 antisera, the crescent localization at the urinary pole had no correlation with the prevalence of epithelial or macrophagic cells. These findings suggest that crescents, due to epithelial proliferation or macrophage clustering, tend to localize at the urinary pole and thus come into close contact with cells of the proximal convoluted tubule: the formation of a sort of plug or a 'glomerular stone' could well explain the block in the urine flow and the consequent impairment of renal function in the acute phase of the disease, even in those cases where crescents are segmental.

Different patterns of renal damage in type 2 diabetes mellitus: a multicentric study on 393 biopsies.

The frequency of various types of renal changes in patients with type 2 diabetes is not clearly defined in the literature. Reported discrepancies likely are caused by ethnic and geographic factors. However, policies used in nephrological centers for the selection of patients to undergo renal biopsy also may have an influence. The present study reports 393 renal biopsies in patients with type 2 diabetes performed in a group of centers in northwestern Italy using different (restricted [CRPs] or unrestricted [CUP]) biopsy policies. On the basis of light microscopic, immunofluorescence, and ultrastructural findings, cases were subdivided into three classes characterized by the presence of diabetic glomerulosclerosis (class 1), prevailing vascular (arterioarteriolosclerotic) and ischemic glomerular changes (class 2), other glomerulonephritides superimposed on diabetic glomerulosclerosis (class 3a), or glomerulonephritides without the presence of diabetic glomerulosclerosis (class 3b). Although no significant differences were found for class 2 (detected in 15% and 16% of patients from CRPs and the CUP, respectively), the frequency of the other two classes was strongly biased by the biopsy policy. Class 1 was found in 29% and 51% of cases, and class 3 in 57% and 33% of cases from CRPs and the CUP, respectively. Moreover, class 3a was more common (67%) in the CUP, and class 3b (78%) in CRPs. Our findings may explain conflicting data from the literature and the influence that type of adopted biopsy policy may have on an epidemiological evaluation. This study helps clarify the frequency of renal changes in patients with type 2 diabetes and suggests more extensive use of renal biopsy to obtain reliable prognostic indications and plan a rational therapeutic approach.