Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic allograft nephropathy is the most prevalent cause of renal transplant failure in the first post-transplant decade, but its pathogenesis has remained elusive. Clinically, it is characterized by a slow but variable loss of function, often in combination with proteinuria and hypertension. The histopathology is also not specific, but transplant glomerulopathy and multilayering of the peritubular capillaries are highly characteristic. Several risk factors have been identified, such as advanced donor age, delayed graft function, repeated acute rejection episodes, vascular rejection episodes, and rejections that occur late after transplantation. A common feature of chronic allograft nephropathy is that it develops in grafts that have undergone previous damage, although the mechanism(s) responsible for the progressive fibrosis and tissue remodeling has not yet been defined. Hypotheses to explain chronic allograft nephropathy include the immunolymphatic theory, the cytokine excess theory, the loss of supporting architecture theory, and the premature senescence theory. The most effective option to prevent chronic allograft nephropathy is to avoid graft injury from both immune and nonimmune mechanisms.
 ...
PMID:Chronic allograft nephropathy: An update. 1046 49

Chronic allograft nephropathy is the principal cause of late graft loss after the first year of renal transplantation. Transforming growth factor-beta1 (TGF-beta1) is a key fibrogenetic cytokine involved in the fibrosis of a number of chronic diseases of the kidney and other organs, and recently evidence has shown that TGF-beta1 is involved in the pathogenesis of chronic renal allograft dysfunction. Production of TGF-beta1 in these circumstances may be modulated by the intrarenal renin-angiotensin system (angiotensin II induces TGF-beta1 production and secretion by the mesangial cells) and by a direct effect of cyclosporin A, which stimulates the synthesis and expression of TGF-beta1. In a prospective study of 14 renal transplant patients exhibiting chronic graft nephropathy, we demonstrated that treatment with losartan significantly decreased plasma levels of TGF-beta1 by >50%. There was a significant correlation (P=0.04) between the increase in circulating angiotensin II after 2 weeks and the decrease in plasma TGF-beta(1) at the end of the study period, suggesting that the degree of angiotensin II receptor blockade plays a decisive role in the synthesis of TGF-beta1. A significant decrease in circulating endothelin-1 (ET-1) levels also occurred during treatment with losartan, together with a decrease in proteinuria. In a randomized 2x2 crossover study, the effects of losartan and amlodipine on renal haemodynamics and on profibrogenetic cytokines were analysed. Whereas amlodipine increased the glomerular filtration rate (GFR) through an increase in the FF and P(G), losartan slightly decreased the GFR, but with a significant decrease in FF and P(G). With respect to the profibrogenetic cytokines, losartan decreased the plasma levels of TGF-beta1 and ET-1, while amlodipine did not significantly change TGF-beta1 and slightly increased ET-1.
 ...
PMID:Role of transforming growth factor-beta1 in the progression of chronic allograft nephropathy. 1136 37

Chronic allograft nephropathy (CAN) represents a frequent and irreversible cause of long-term renal graft loss. TGF-beta1 is a key profibrogenic cytokine associated with CAN pathogenesis. Because of clinical diagnostic inaccuracy, protocol biopsy has been suggested to be a beneficial method for early CAN detection. Protocol core biopsy was carried out in 67 consecutive cyclosporine-based immunosuppression-treated kidney transplant recipients with stable renal function 12 months after renal transplantation. Biopsy specimens were analyzed morphologically according to Banff-97' criteria and immunohistologically for TGF-beta1 staining. The data obtained were correlated with plasma TGF-beta1 levels and clinical data. CAN (grade I-III) was found in 51 patients (76 %). CAN grade I was found to be the most frequent one (44 %). A normal finding within the graft was made in only 12 patients (18 %). Clinically silent acute rejection Banff IA was present in 4 patients (6 %). In 8 patients (12 %) with CAN, borderline changes were present. We found a significant correlation between CAN grade and creatinine clearance, as measured by the Cockroft-Gault formula (p<0.01) as well as body mass index (p<0.01). There was a significant correlation between chronic vasculopathy (Banff cv) and creatinine clearance, and between the degree of TGF-beta1 staining and chronic vasculopathy (p<0.01). There were no relations between morphological findings and TGF-beta1 plasma levels, cyclosporine levels, plasma lipids, HLA-mismatches, panel reactive antibodies (PRA), proteinuria, and the donor's age. In conclusion, CAN is a frequent finding in protocol kidney graft biopsies 12 months after transplantation. TGF-beta1 tissue expression is linked with chronic vasculopathy.
 ...
PMID:TGF-beta1 expression and chronic allograft nephropathy in protocol kidney graft biopsy. 1279 Jul 68

Chronic allograft nephropathy (CAN) remains a significant cause of late renal allograft loss. Although many factors may be involved in pathogenesis, the hemodynamic and fibrogenic consequences of long-term therapy with cyclosporine (CsA) have been implicated as important potentially reversible causes. CsA's effect on CAN is mediated in part through increased renal expression of TGF-beta, which can be modified by administration of angiotensin receptor blockers (ARBs). A pilot study was undertaken to evaluate the safety and efficacy of the ARB valsartan on renal function and proteinuira in patients with CAN. Ten patients on CsA-based therapy with evidence of CAN received valsartan in an initial dose of 80 mg/d, force titrated to 160 mg/d after 4 weeks, for a total of 52 weeks. Renal function was evaluated by serum creatinine, 24-hour creatinine clearance (CrCl), and isotope, GFR and urinary protein by 24-hour protein excretion. The 10 patients were aged 20 to 71 years and had been transplanted for 88.2 +/- 64.8 months at the time of study. After 52 weeks of valsartan therapy mean blood pressure (BP) fell from 152/88 mm Hg to 138/77 mm Hg (P =.06); serum creatinine rose from 206 +/- 55 micromol/L to 238 +/- 81 micromol/L (P =.22.); GFR fell from 39.8 +/- 17.6 to 31.9 +/- 19 mL/min (P =.23); and urine protein fell from 2.16 +/- 2.7 to 1.12 +/-.095 g/24 hours (P =.13). Side effects of valsartan therapy were few and included transient hyperkalemia in 2/10 patients. The small rise in serum creatinine and fall in GFR observed were not statistically significant. Urine protein fell by more than 50%, though the small patient numbers in this pilot study prevent this from achieving statistical significance. It is concluded that valasartan reduces BP and proteinuria in CAN patients without inducing a serious worsening in renal function. Valsartan may have a role to play in the management of patients with CAN.
 ...
PMID:Effect of valsartan on urinary protein excretion and renal function in patients with chronic renal allograft nephropathy. 1461 73

Chronic allograft nephropathy (CAN) is the most important cause of late renal allograft loss. The standard diagnosis of CAN is based on pathological examinations according to Banff'97 scheme. The aim of the study was to evaluate the usefulness of tubular and glomerular proteinuria in non-invasive recognition of vascular changes accompanying CAN (AH--arteriolar hyaline thickening, CV--vascular fibrous intimal thickening). beta 2- and alpha 2-microglobulin (beta 2-m and alpha 2-m), albumin (alb), immunoglobulin G (IgG), total protein (tp) and creatinine (cr) concentration were measured in the second time urine specimen in 66 renal allograft recipients. Then the subsequent renal biopsies were done. The aim of statistical analysis (MANOVA, Stepwise Discriminant Analysis, SDA) was to diagnose CV and AH changes based on results of urine analysis listed above and the patient's age, time after transplantation and serum creatinine level (scr). Results obtained with statistical analysis were in 90.91% and 87.69% identical with CV and AH pathological diagnoses, respectively.
 ...
PMID:[The usefulness of tubular and glomerular proteinuria measurement in non-invasive diagnosis of vascular changes accompanying chronic allograft nephropathy]. 1497 66

Chronic allograft nephropathy (CAN) represents an important cause of graft loss after kidney transplantation. TGF-beta1 is a key factor in fibrogenesis, and the angiotensin II receptor antagonist losartan may decrease the intra-graft synthesis of TGF-beta1. The aim of this study was to determine the clinical and molecular effect of losartan in kidney transplant patients (KTPs) with CAN. We studied nine KTPs, after the first year of transplantation, with proteinuria (more than 500 mg/24 h), stable renal function, and histological signs of CAN. Immunosuppression was cyclosporine, azathioprine, and corticoids. Kidney biopsy was performed in all patients at the beginning of the study and 12 weeks after treatment with 50 mg/day of losartan. Quantitation of intra-graft expression of TGF-beta1 was performed in all biopsies, by real-time PCR. After losartan treatment there were no differences in patients' BP and blood creatinine level. The proteinuria significantly dropped to 414.2+/-377 mg/24 h, P=0.001. Intra-graft expression of TGF-beta1 was decreased after treatment. In conclusion, losartan significantly decreases the intra-graft expression of TGF-beta1 and proteinuria in KTPs with CAN.
 ...
PMID:Molecular and clinical response to angiotensin II receptor antagonist in kidney transplant patients with chronic allograft nephropathy. 1534 18

Histopathological features of transplanted kidneys which gradually lose graft function have been traditionally reported with the term of chronic rejection (CR). In 1997 Banff's classification indicated the adoption of a new term for all these histological features, namely Chronic allograft nephropathy (CAN), recommending that the presence of morphological aspects suggestive of chronic rejection, such as chronic transplant glomerulopathy (CTG) and proliferative endoarteritis (PE), has to be specified. On the basis of these criteria we reviewed the renal biopsies of 92 patients who underwent kidney transplantation from 1999 to 2002. In all cases the biopsy had been performed 6 months after organ transplantation. In 30 of the 92 patients CTG and/or PE was evident supporting a diagnosis of CR; on the contrary, in 11 of the 92 patients the final diagnosis based on histological evidence was that of CAN. Clinical and laboratory tests revealed that the presence of proteinuria in patients with CR at the time of diagnosis was the single statistically significant difference between these two groups. In 7 of the 32 patients where the diagnosis of CR was based on the presence of early features of CTG, the treatment with ACE-I induced complete remission of the proteinuria. Cyclosporine-induced arteriolopathy (CSA) represents an additional histological finding which has been associated with graft loss in the transplanted kidney. The observation of arteriolopathy, similar to CSA in patients who did not receive calcineurine inhibitors, suggests some caution in the use of this diagnostic criteria.
 ...
PMID:[Clinical anatomical features of chronic dysfunction in the transplanted kidney]. 1573 43

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.
 ...
PMID:[Therapy strategies in the prevention of chronic allograft nephropathy]. 1578

It has been proposed that proteinuria occurring after renal transplantation may be not only a marker but also a culprit of allograft dysfunction. We retrospectively analyzed the data from 55 patients who underwent transplant renal biopsy for proteinuria and/or azotemia occurring beyond 1 year after transplantation. Proteinuria was considered as significant when > or = 30 mg/dL, and the results of transplant biopsy were categorized according to the Banff 97 classification. Logistic regression was used to estimate odds ratios (OR) for graft loss associated with proteinuria and transplant pathology. The patients were followed for 86.0 +/- 32.8 months after transplantation, and transplant biopsy was performed at 54.1 +/- 31.0 months. Proteinuria at 1 year after transplantation noted in 29.1% of patients was not significantly associated with graft loss (OR = 1.94, 95% CI from 0.59 to 6.41). In addition, proteinuria at the time of transplant biopsy was not significantly associated with graft loss. Chronic allograft nephropathy was the most frequent transplant pathology. Only glomerulonephritis was significantly associated with proteinuria at the time of the transplant biopsy. On the other hand, graft loss was significantly associated with the presence of proteinuria both at 1 year after transplant biopsy and at the final follow-up. These results suggest that posttransplantation proteinuria is an important marker of graft dysfunction, but is not predictive of graft loss in biopsy-proven cases. Appropriate management guided by the results of a transplant biopsy may improve the outcome.
 ...
PMID:Analysis of allograft biopsy specimens in renal transplants with proteinuria: is proteinuria a culprit of graft loss? 1584 98

Chronic allograft nephropathy (CAN) is the leading cause of graft loss following kidney transplantation. One factor contributing to CAN is chronic alloimmune injury. However, the involvement of alloantigen-dependent and -independent factors in CAN is unclear. The pathomechanism of CAN has been extensively studied by utilizing the Fischer-to-Lewis (F344-to-LEW) rat model. Transplant capillaropathy (circumferential multiplication of the peritubular capillary basement membrane) and transplant glomerulopathy (reduplication of the glomerular basement membrane) have recently been validated clinicopathologically as ultrastructural indicators of chronic alloimmune injury. To investigate the presence of these markers, F344-to-LEW kidneys were examined by electron and light microscopy 32, 40 and 52 weeks after implantation. F344 rats with or without 30-min ischemia of the left kidney following right nephrectomy served as controls. All transplanted rats displayed marked proteinuria. On electron microscopy, transplant capillaropathy, transplant glomerulopathy, and T-cell cytotoxicity (indicator of ongoing cellular rejection) were absent. On light microscopy, the arteries were devoid of intimal fibrosis. Focal-segmental glomerulopathy resembling hyperfiltration injury was encountered, with mild interstitial infiltration, fibrosis, and tubular atrophy. The proteinuria and kidney pathology were more severe in transplanted than in ischemic or uninephrectomized rats. Because chronic-active rejection could not be detected between weeks 32 and 52, we propose that the alloantigen-dependent initial graft injury subsides, but induces the late events: glomerular hyperfiltration, proteinuria, and glomerulosclerosis. Accordingly, the model - in the late phase - is suitable to investigate alloantigen-independent factors of CAN and lacks markers of alloantigen-dependent processes.
 ...
PMID:Ultrastructural analysis of the Fisher to Lewis rat model of chronic allograft nephropathy. 1594 67


1 2 3 Next >>