Cyclosporine Nephrotoxicity Research Articles

Colchicine Suppresses Osteopontin Expression and Inflammatory Cell Infiltration in Chronic Cyclosporine Nephrotoxicity

Background: Colchicine (Col) is beneficial to renal injury because of its anti-inflammatory effect, but its mechanism has yet to be elucidated. The present study was designed to evaluate the inhibitory effects of colchicine on osteopontin (OPN) expression and the macrophage accumulation in chronic cyclosporine (CsA) nephrotoxicity in rats. Methods: Male adult Sprague-Dawley rats on a low salt diet (LSD, 0.05% sodium) were treated daily with Col (30 µg/kg), CsA (15 mg/kg), and both CsA and colchicine or vehicle (olive oil 1 ml/kg) for 4 weeks. The effects of colchicine on chronic CsA nephrotoxicity were evaluated by examining renal function, histopathology, and ED-1 positive cells. The expressions of OPN mRNA and protein were estimated respectively by Northern blot and immunohistochemistry. Results: Compared with vehicle-treated rats, CsA-treated rats showed an increase in serum creatinine, a decline in creatinine clearance rate, and tubulointerstitial fibrosis (all p < 0.01). Concomitant administration of colchicine reversed all of the above parameters (all p < 0.01). Of note, the upregulated expression of osteopontin mRNA and protein seen in CsA-treated rats was significantly decreased after colchicine treatment. Furthermore, the expression of osteopontin mRNA was strongly correlated with the number of ED-1 positive cells (r = 0.712, p < 0.001) and the tubulointerstitial fibrosis score (r = 0.586, p = 0.007). Conclusion: Colchicine is capable of abrogating the upregulation of chemotactic OPN expression and macrophage influx, and this is associated with improved renal tubulointerstitial fibrosis in chronic CsA nephrotoxicity.

Reversal of chronic cyclosporine nephrotoxicity after heart transplantation—potential role of mycophenolate mofetil

Background Chronic cyclosporine nephrotoxicity (CCN) after heart transplantation is a progressive condition that may lead to end-stage renal failure. The extent to which CCN is reversible with reduction or withdrawal of cyclosporine therapy is unknown. The aim of this study was to assess the reversibility of CCN and to assess the safety and efficacy of a strategy of cyclosporine dosage reduction, combined with conversion from azathioprine to mycophenolate mofetil (AZA/MMF switch) to maintain immunosuppression. Methods An AZA/MMF switch followed by cyclosporine dose reduction was undertaken in 30 heart transplant recipients (23 men, 7 women; mean age, 54 ± 2 years) with established CCN at a mean of 90 ± 9 months after transplantation (range, 17–182 months). The mean maintenance MMF dosage was 2.3 ± 0.1 g/day ( n = 28). Mean cyclosporine dosage was decreased from 2.3 ± 0.2 mg/kg/day before AZA/MMF switch to 1.6 ± 0.2 mg/kg/day. Results Three patients (10%) were withdrawn from MMF, 2 because of diarrhea and the third because of severe pneumonia that developed within 2 weeks of AZA/MMF switch. All 3 were restabilized with AZA. One patient (4%) experienced acute rejection 7 months after AZA/MMF switch. This resolved after an oral pulse of prednisolone. Systemic infections occurred in 6 patients within 12 months of AZA/MMF switch. Actuarial survival 1 year after AZA/MMF switch was 86% ± 6%. One patient died of infection and 3 of other causes. Serum creatinine concentration decreased from 248 ± 15 μmol/liter before cyclosporine dosage reduction to 193 ± 11 μmol/liter and 206 ± 19 μmol/liter at 3 and 12 months after dosage reduction (both p < 0.01 versus baseline, n = 23). Of the 23 patients who remained on MMF at 12 months, a decrease in serum creatinine was documented in 19 (83%). Four patients showed no improvement or showed deterioration in renal function, and three of these progressed to end-stage renal failure. Conclusions Chronic cyclosporine nephrotoxicity has a significant reversible component in most patients. A strategy of AZA/MMF switch combined with cyclosporine dosage reduction is generally well tolerated and results in short-term improvement in renal function in most patients. Close vigilance is required during the first 12 months after AZA/MMF switch because both acute rejection and infection may occur.

Angiotensin II regulation of vascular endothelial growth factor and receptors Flt-1 and KDR/Flk-1 in cyclosporine nephrotoxicity

Vascular endothelial growth factor (VEGF) is involved in angiogenesis, wound healing and inflammation. VEGF exerts its effect via the tyrosine kinase receptors Flt-1 and KDR/Flk-1. We have previously shown that VEGF is up-regulated in a chronic cyclosporine (CsA) nephrotoxicity model. Our current study examined the role of angiotensin II (Ang II) blockade with enalapril (E) or losartan (L) on VEGF in this model. Pair-fed salt-depleted rats were administered vehicle, CsA, CsA + nilvadipine, CsA + hydralazine/hydrochlorthiazide (HCTZ), CsA + E or CsA + L, and were sacrificed at 7 or 28 days. Physiologic and histologic changes were studied in addition to the mRNA expression of VEGF and its receptors Flt-1 and KDR/Flk-1 by Northern blot, and the protein expression of VEGF by Western blot. While all groups achieved similar blood pressures and creatinine clearances, the amelioration in nephrotoxicity was observed only with Ang II blockade. VEGF mRNA and protein expressions increased with CsA and became significantly reduced with Ang II blockade. Flt-1 expression was similar in all groups; it decreased early and remained low. On the other hand, KDR/Flk-1 mRNA expression was higher at seven days in all groups, except in the +E and +L groups where it was significantly lower, and then became further down-regulated at 28 days. The increased VEGF expression in chronic CsA nephrotoxicity seems to be related to up-regulation of Ang II. In addition, VEGF probably exerted its effect via the KDR/Flk-1 receptor. The actions of VEGF in this model remain speculative, but may be related to its effect on macrophage infiltration or matrix deposition.

Cyclosporine withdrawal and mycophenolate mofetil treatment effects on the progression of chronic cyclosporine nephrotoxicity

Recent clinical trials of mycophenolate mofetil (MMF) in chronic allograft nephropathy (CAN) demonstrated that the dose of cyclosporine A (CsA) is one of the critical factors in determining graft function in CAN, but the effect of MMF on chronic CsA nephropathy is undetermined. We undertook this study to evaluate the effect of MMF on CsA-induced nephrotoxicity in an animal model of chronic CsA nephropathy. In the first experiment, Sprague-Dawley rats on a low-salt diet were treated with CsA (7.5 mg/kg per day) for 10 weeks, or were treated with CsA for five weeks and then MMF (20 mg/kg per day) was administered five weeks later. In the second experiment, rats were treated with CsA for five weeks, and CsA was then withdrawn for five weeks with or without MMF treatment. Renal function, histologic parameters (tubulointerstitial fibrosis, arteriolopathy, ED-1-positive cells, renin-positive glomeruli, TUNEL-positive cells) and the expression of osteopontin and transforming growth factor (TGF)-beta1 mRNA expressions were compared for different treatment groups. CsA-treated rats showed decreased renal function and increased histologic parameters compared with the vehicle (VH)-treated rats. The addition of MMF did not improve these parameters compared with the CsA-treated rats. With CsA withdrawal, renal function and histologic parameters were significantly improved compared with the CsA-treated rats, and MMF treatment after CsA withdrawal further improved the histologic parameters. At the molecular level, the addition of MMF did not decrease the expression of osteopontin and transforming growth factor-beta1 (TGF-beta1) mRNAs, which were increased in the CsA-treated rat kidney. With CsA withdrawal, the expression of both mRNAs was significantly decreased compared with the CsA group, and a further decrease was observed with MMF treatment after CsA was withdrawn. The combined treatment of CsA and MMF does not prevent the development of chronic CsA nephrotoxicity, but MMF treatment after CsA withdrawal does improve chronic CsA nephrotoxicity. This finding provides a rationale for MMF treatment in chronic CsA nephrotoxicity.

Nephrotoxicity of cyclosporine A and amphotericin B-deoxycholate as continuous infusion in allogenic stem cell transplantation.

Nephrotoxicity is an important side effect of amphothericin B deoxycholate (ampho B) and cyclosporine A (CsA). The combined administration of these drugs is frequent in patients with haematological diseases undergoing allogeneic stem cell transplantation. To assess the additional renal toxicity of ampho B given as a continuous infusion in addition to CsA. In a retrospective study renal function was investigated in patients receiving CsA alone or in combination with ampho B (24-hour infusion) after allogeneic stem cell transplantation between January 1998 and April 2001. Of a total of 84 patients, 22 were treated with ampho B. There was a statistically significant decline in renal function in comparison to the 62 patients receiving CsA alone. However, renal insufficiency in all patients remained in a clinically acceptable range and was reversible. The residual renal dysfunction at the end of the hospitalisation was mainly due to continuing therapy with CsA. Amphotericin B deoxycholate in addition to CsA leads to a statistically significant but clinically tolerable worsening of renal function. Using a 24-hour infusion and strict salt repletion, amphotericin B can be administered safely as deoxycholate in bone marrow transplant patients in conjunction with CsA for proven or suspected fungal infections.

Nephrotoxicity of cyclosporine A and amphotericin B-deoxycholate as continuous infusion in allogenic stem cell transplantation.

Nephrotoxicity is an important side effect of amphothericin B deoxycholate (ampho B) and cyclosporine A (CsA). The combined administration of these drugs is frequent in patients with haematological diseases undergoing allogeneic stem cell transplantation. To assess the additional renal toxicity of ampho B given as a continuous infusion in addition to CsA. In a retrospective study renal function was investigated in patients receiving CsA alone or in combination with ampho B (24-hour infusion) after allogeneic stem cell transplantation between January 1998 and April 2001. Of a total of 84 patients, 22 were treated with ampho B. There was a statistically significant decline in renal function in comparison to the 62 patients receiving CsA alone. However, renal insufficiency in all patients remained in a clinically acceptable range and was reversible. The residual renal dysfunction at the end of the hospitalisation was mainly due to continuing therapy with CsA. Amphotericin B deoxycholate in addition to CsA leads to a statistically significant but clinically tolerable worsening of renal function. Using a 24-hour infusion and strict salt repletion, amphotericin B can be administered safely as deoxycholate in bone marrow transplant patients in conjunction with CsA for proven or suspected fungal infections.

Colchicine decreases apoptotic cell death in chronic cyclosporine nephrotoxicity

Colchicine has been shown to prevent kidney injury in chronic cyclosporine nephrotoxicity; however, the mechanisms of its action are undetermined. The purpose of this study was to clarify whether colchicine prevents cyclosporine-induced kidney injury by decreasing kidney-cell apoptosis. We also sought to determine whether such an antiapoptotic effect was related to Bcl-2/Bax protein and caspase3 activity. Adult male Sprague-Dawley rats kept on a salt-depleted diet (0.05% sodium) were treated daily for 28 days with cyclosporine (15 mg/kg in 1 mL/kg olive-oil vehicle), colchicine (30 μg/kg in 100% ethanol, diluted with sterile saline solution to a final concentration of 30 μg/mL), or both cyclosporine and colchicine. Kidney function, histomorphologic findings, in situ terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate-biotin nick end-labeling assay, expressions of Bcl-2 and Bax proteins, and caspase-3 enzymatic activity were compared for the different treatment groups. Compared with the vehicle-treated rats, rats given cyclosporine showed a decline in creatinine clearance rate, an increase in serum creatinine concentration, tubulointerstitial fibrosis, and an increase in the number of apoptotic cells (all P <.01). Concomitant administration of colchicine significantly reversed all the above parameters (all P <.05). The decreased expression of Bcl-2 and the ratio of Bcl-2 to Bax protein seen in cyclosporine-treated rat kidneys were significantly increased after colchicine treatment, accompanying a suppression of caspase-3 activity (P <.05). Furthermore, the decreased apoptotic cell death was closely correlated with improved renal tubulointerstitial fibrosis (r = 0.583, P <.05). These findings strongly suggest that a renoprotective effect of colchicine on cyclosporine-induced nephrotoxicity is coassociated with a decrease in apoptotic cells. (J Lab Clin Med 2002;139:364-71)

Expression of Apoptosis-related Genes in Chronic Cyclosporine Nephrotoxicity in Mice

To define the mechanism of cyclosporine (CsA)-induced apoptosis, we investigated the expression of apoptosis-related genes in experimental chronic CsA nephrotoxicity. Mice on a low-salt (0.01%) diet were given vehicle (VH, olive oil, 1 mg/kg/day), or CsA (30 mg/kg/day), and sacrificed at 1 and 4 weeks. Apoptosis was detected with deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) stain, and the expressions of apoptosis-related genes were evaluated by reverse transcription-polymerase chain reaction, immunoblot or immunohistochemistry. The activity of caspase 1 and 3 was also evaluated. The CsA group showed increases in apoptotic cells compared with the VH group (54 +/- 41 vs. 3 +/- 3, p < 0.05), and the number of apoptotic cells correlated well with interstitial fibrosis scores (r = 0.83, p < 0.01). The CsA group showed a significant increase in Fas-ligand mRNA (0.20 vs. 0.02 amol/microgram total RNA, p < 0.05) and Fas protein expression (146% vs. 95%, p < 0.05), compared with the VH group. The CsA group showed significant increases in ICE mRNA (0.21 vs. 0.03 amol/microgram total RNA at 4 weeks, p < 0.05) and CPP32 mRNA (0.18 vs. 0.03 amol/microgram total RNA at 4 weeks, p < 0.05), compared with the VH group. The enzymatic activity of ICE (16.6 vs. 7.9 rho mol/microgram/h, p < 0.05) and CPP32 protease (15.6 vs. 2.7 rho mol/microgram/h, p < 0.05) proteases were increased in the CsA group, compared with the VH group. The ratio between bax and bcl-2 protein increased significantly in the CsA group (5.3-fold), compared with the VH group. Levels of p53 protein also increased in the CsA group. Immunohistochemical detection of Fas, Fas-ligand, ICE and CPP32 revealed strong immunoreactivity in renal tubular cells in areas of structural injury. These findings suggest that local activation of the apoptosis-related genes is associated with CsA-induced apoptotic cell death.

Tacrolimus (FK506) versus cyclosporine nephrotoxicity in heart transplant recipients: a four-year follow-up

Tacrolimus (FK506) versus cyclosporine nephrotoxicity in heart transplant recipients: a four-year follow-up

Pirfenidone Treatment Decreases Transforming Growth Factor-β1 and Matrix Proteins and Ameliorates Fibrosis in Chronic Cyclosporine Nephrotoxicity

Chronic cyclosporine (CsA) nephrotoxicity is characterized by tubulointerstitial fibrosis. Pirfenidone (PFD) is a novel antifibrotic compound that was shown to prevent and even reverse fibrosis. The mechanism of action of PFD is unclear but involves inhibition of transforming growth factor-beta (TGF-beta). Salt-depleted rats were administered CsA, CsA + PFD, vehicle (VH) or VH + PFD and sacrificed at 28days. Physiologic and histologic changes were studied in addition to TGF-beta1, plasminogen activator inhibitor-1 (PAI-1) and biglycan mRNA expressions by Northern blot. TGF-beta1 immunohistochemistry was also performed. Treatment with PFD ameliorated CsA-induced fibrosis by about 50% (p < 0.05). CsA-induced decrease in creatinine clearance improved with PFD but the difference was not significant. TGF-beta1, PAI-1 and biglycan mRNA expressions increased with CsA (p < 0.05 vs. VH) but strikingly improved with PFD treatment (p < 0.05 vs. CsA), which brought the levels down to VH levels. PFD treatment also decreased TGF-beta1 protein expression by 80%. These results demonstrate that PFD can attenuate renal fibrosis in this model. PFD was associated with a decrease in TGF-beta1 expression, which, in turn, was associated with a decrease in matrix deposition. These experiments suggest that PFD can be clinically useful for preventing chronic CsA nephrotoxicity and may prove to be helpful in other progressive renal diseases.

Evaluation of the rate of progression of chronic renal transplant rejection using the proliferating cell nuclear antigen

Since the introduction of kidney transplantation, the short-term patient and graft survival have been progressively improving, but the long-term graft survival and half-life of transplants have not. Beyond doubt, chronic rejection (CR) remains the major cause of chronic graft failure and is responsible for the loss over 10 years of 50% of grafts. (1-4). CR is characterized clinically by proteinuria, hypertension and declining renal function, and pathologically by arteriosclerosis, glomerulosclerosis and interstitial fibrosis. The progressive morphological changes of glomerular, vascular and tubulointerstitial (TIN) compartments in renal allografts experiencing chronic rejection correlate directly with declining renal function and the eventual graft loss [5]. In consideration of this fact and using proliferating cell nuclear antigen (PCNA) as a marker of cell proliferation, a retrospective analysis of renal allograft biopsies was carried out with the aim to determine whether quantification of the cell proliferation activity in three tissue compartments may be used as a prognostic index of CR progression. Clinical course and biopsy specimens of 27 patients with clinically and morphologically confirmed (Banff schema) diagnosis of CR were retrospectively evaluated. Patients were transplanted between 1988 and 1994 at our Institute and regularly followed-up for at least 2 years after transplantation (14 patients), or till haemodialysis has been resumed (11 patients) or till death (2 patients). The progression rate of renal graft function deterioration was estimated by slopes of regression lines obtained by plotting 1/sCr vs time. According to the progression rate after biopsy patients were divided into two groups: fast progression group (10 patients) and slow progression group (17 patients). Immunosuppressive regimens included induction with anti-lymphocyte globulin followed with cyclosporine, steroids and azathioprine. Immunohistochemistry. Sections of formalin-fixed, paraffinembedded tissue were stained for PCNA with monoclonal mouse anti-proliferating cell nuclear antigen (clone PC 10, Dako) as follows in ref. [6]. PCNA immunoreactivity of smooth muscle cells and lymphocytes in vascular intima, lymphocytes in TIN and glomerular mesangium proliferation was assessed by semiquantitative scoring (scale 0-3). Normal tonsil was used as a positive control. Differences between groups were evaluated using Student's t-test. Pearson's correlation test was used to study the relationship between variables. P values < 0.05 were considered as significant. Data on patients are presented in Table 1. The only statistical difference was in progression of chronic graft failure presented by regression lines obtained by plotting 1/sCr vs time. PCNA protein expressions in vascular, glomerular and TIN compartments for both groups are presented in Figs. 1-3.. PC 10 immunoreactivity was confined to the nucleus. The pattern of staining was granular or diffuse. Individual values of the scores of PCNA immunoreactivity in different tissue compartments for the groups examined are presented in Tables 2 and 3. Comparison of the means of PCNA immunoreactivity scores in different tissue compartments of fast and slow progression group showed that cells proliferation in glomerular, TIN and vascular compartments are significantly higher in the fast than in the slow progression group (Table 4). Besides, significant positive correlation was found between the slopes of the regression lines plotting 1/sCr vs. time and cells proliferation scores for all compartments (Table 5). Chronic graft failure may occur due to CR, cyclosporine nephrotoxicity, repeated acute rejection, recurrent glomerular diseases, surgical and urological complications, but CR was recognized as the most common cause of chronic graft failure and renal graft loss [7]. Progression of renal disease reflects the interactive effects of changes in the structure and function. This notion has been examined many times in the native kidneys by studies correlating glomerular filtration rate with architectural deterioration in the glomerular or interstitial compartment [8-10]. Meanwhile, the similar studies in human renal allograft are scarce. Increased PCNA immunodetection in glomerular cells as well as in interstitial infiltrates was described in acute and chronic renal graft rejection and diagnostic value of this finding was analyzed [12, 15]. Similarly, PCNA was often examined immunohistochemically in lymphoma and solid tumours as a marker of cell proliferation, but its reliability as a prognostic factor was also evaluated [18-20]. In the present study the prognostic value of PCNA expression in different tissue compartments of renal grafts experiencing CR was examined for the first time. The present study revealed that two groups examined with the different chronic graft failure progression rate as the main difference had significantly different proliferation of cells in glomerular, TIN and vascular compartments. PCNA immunoreactivity scores in these three compartments were significantly higher in the fast than in slow progression group. The significant positive correlation between the slope of the regression line plotting 1/sCr vs. time and cell proliferation in glomerular, TIN and vascular compartments was also found. Therefore, it was suggested that the measurement of PCNA expression in renal graft tissue might be used as a prognostic index.

Long term results of liver-kidney transplantation in children with primary hyperoxaluria

From 1990 to 2000, we performed eight liver-kidney transplants in eight children, aged 1-16 years, with end-stage renal failure (ESRF) due to primary hyperoxaluria (PH1). The duration of dialysis before transplantation ranged from 2 to 42 months (mean 14 months) and was <1 year in four patients. Only the first patient underwent postoperative hemodialysis; in the other five, we chose to induce maximal diuresis from the first hours with intravenous and intragastric hyperhydration (> or =3 l/m2 per day). High water intake with nocturnal tube hydration was maintained for 6 months to 5 years, as long as oxaluria exceeded 0.5 mmol/day. A quadruple sequential immunosuppressive regimen was used. Two patients died during liver graft surgery. The other six patients are alive and well, with a mean follow-up of 7.4 years (range 5-11 years). Patient and graft survival is 75% at 5 years. At latest follow-up, liver tests were normal in all six patients; creatinine clearance ranged from 55 to 95 ml/min per 1.73 m2 (mean=74). Oxaluria was lower than 0.4 mmol/day in all patients (mean=0.22). The six patients underwent 15 renal biopsies, 1-11 years after transplantation. Chronic transplant nephropathy was present in four patients and mild cyclosporin nephrotoxicity in another. No oxalate crystals were seen and repeat ultrasonography has been consistently normal in all patients. The three patients with bone oxalosis showed progressive complete healing of bone lesions. All six children or adolescents now live a normal life. From this series, we conclude that early combined liver-kidney transplantation is the treatment of choice for children with ESRF due to primary hyperoxaluria.

The Value of Electron Microscopy in the Diagnosis of Chronic Renal Allograft Rejection

The main causes of the late dysfunction of renal allografts are chronic rejection and chronic transplant nephropathy. Both are clinicopathologic entities, with a similar clinical presentation, but different histologic appearances. Chronic rejection is characterized by the presence of alloantigen-induced lesions (transplant arteriopathy and transplant glomerulopathy), and chronic transplant nephropathy by nonspecific sclerosing changes. The incidence of transplant arteriopathy and transplant glomerulopathy is relatively low. Electron microscopy (EM) may overcome the limitations in the histologic diagnosis of chronic rejection, because it verifies alloantigen-induced chronic microvasculopathy in the peritubular capillaries (transplant capillaropathy), and identifies transplant glomerulopathy more precisely than does light microscopy. To assess the value of EM in chronic rejection diagnosis, a retrospective search for transplant capillaropathy and transplant glomerulopathy was performed in a consecutive series of 91 biopsies performed ≥6 months after implantation (median: 26 months, range 6–186) and the diagnoses were reclassified on the basis of the ultrastructural findings. The definitions used were: transplant capillaropathy: a peritubular capillary profile with seven or more circumferential basement membrane layers, or at least three profiles with five or six circumferential layers; ultrastructurally verified transplant glomerulopathy: thickening of the capillary wall in at least three loops in consequence of the widening of the subendothelial space by abnormal basement membrane material, and the formation of a new layer(s) of basal lamina; and chronic rejection: the presence of transplant capillaropathy and/or transplant glomerulopathy and/or transplant arteriopathy. Histologically, chronic transplant nephropathy, chronic rejection, chronic cyclosporine nephrotoxicity, glomerulonephritis, acute rejection, “suspicious” for acute rejection, and “others” were diagnosed in 37%, 34%, 21%, 19%, 57%, 30%, and 5% of the specimens, respectively. The results of EM increased the diagnosis of chronic rejection to 69% of the cases, and decreased chronic transplant nephropathy to 15%. The individual incidence of transplant capillaropathy and transplant glomerulopathy was 79% and 57%, respectively, and their cumulative incidence was 92%. Five biopsies exhibited merely transplant arteriopathy. A late dysfunction typically had more than one cause; the most frequent combination was chronic rejection and acute rejection. In conclusion, the EM search for transplant capillaropathy and transplant glomerulopathy doubled the frequency of the diagnosis of chronic rejection. Currently, the evaluation of renal allograft biopsies from recipients with a late dysfunction relies on standard light microscopy. Because light microscopy per se proved to be insensitive in the diagnosis of chronic rejection, incorporation of EM into the evaluation of late dysfunction biopsies is strongly recommended.

End‐stage renal disease in liver transplants

Renal dysfunction is one of the most significant problems following orthotopic liver transplantation (OLTx). Since the major risk factor for delayed renal dysfunction following OLTx is presumed to be cyclosporine (CsA) nephrotoxicity, it has been suggested that CsA is the most probably cause of end-stage renal disease (ESRD) in this population of patients. To test this hypothesis the records of OLTx patients in our center who developed ESRD requiring dialysis were reviewed. There were 132 consecutive adult patients with end-stage liver disease (ESLD) who received 146 OLTxs between 1990 and 2000. Five patients (3.4%) developed ESRD requiring dialysis. Four of the five patients developed nephrotic range proteinuria prior to reaching ESRD. Renal biopsy in four patients showed focal segmental glomerulosclerosis, diabetic nephropathy, membranous nephropathy and cyclosporine toxicity. The underlying hepatic and metabolic disease may have played a role in the genesis of glomerular diseases in these OLTx patients. Perhaps if more renal biopsies are performed in OLTx patients with chronic renal failure, we might discover that, although CsA/tacrolimus therapy is a definite risk factor for post-transplantation chronic renal failure, other disease processes may also play a significant role.

Impact of schistosomiasis on patient and graft outcome after renal transplantation: 10 years' follow-up.

Schistosomiasis is a major health problem in some areas of the world. Schistosomal-specific nephropathy is a well-known occurrence and eventually leads to end-stage renal failure. Patients with schistosomal infection were considered to be suitable recipients for renal transplantation. However, the long-term impact of schistosomiasis on kidney transplantation is not yet been reported. The long-term impact of schistosomiasis on patient and graft outcomes was studied by comparing two groups of subjects from a total of 243 patients. Group I consisted of cases with schistosomal infections and group II consisted of schistosoma-free controls. Schistosomiasis was documented in group I by identifying schistosoma eggs in urine, stool or rectal mucosal biopsy. Also intra-operative biopsies from bladder mucosa of the graft recipients and from the lower end of the ureter of living donors were obtained to search for schistosoma eggs. Sixty-three cases of schistosomiasis were diagnosed in both recipients and donors, 65 cases in recipients only, and eight cases in donors only. Infected recipients and donors with active lesions were treated at least 1 month before transplantation by combined antischistosomal drugs (praziquantel and oxamniquine). The 243 patients (136 schistosoma-infected cases and 107 controls) were followed regularly for a period of 10 years after transplantation. We found that there was no significant difference in the incidence of acute and chronic rejection between the groups; however, higher cyclosporin doses were needed for the infected group with subsequent higher incidence of both acute and chronic cyclosporin nephrotoxicity. Moreover, the schistosomal group had a significantly higher incidence of urinary tract infection and urological complications with no evidence of schistosomal re-infection. Despite a higher incidence of schistosoma-related complications after renal transplantation, schistosomal infection is not a major risk factor for transplantation. Therefore, infected patients can be considered as suitable recipients if they have been properly treated before transplantation.

Proteinuria as a useful clinical marker of cyclosporine nephrotoxicity in renal transplant patients

A SIGNIFICANT improvement in the success of organ transplantation during the last 20 years has been observed mainly due to the introduction of drugs like cyclosporine (CyA). Although nephrotoxicity (NT) is the major dose-limiting adverse event for this drug, most of immunosuppressive regimens continue to depend on CyA. CyA trough blood levels must be monitored to ensure that the concentration of this drug remains within its narrow therapeutic range. However, it has been questioned because of its inability to adequately reflect systemic exposure in terms of area under the curve. Unfortunately, drug monitoring may not always detect or prevent NT. NT is difficult to distinguish from chronic allograft rejection, which is a particular problem in renal transplantation. Although morphologic criteria for the differential diagnosis between chronic rejection (CR) and CyA-associated NT have been proposed, the risk of biopsy is limiting. Early biopsies are strongly recommended for patients whose serum creatinine levels increase from baseline values. When biopsies are performed too late, after months or years of severe impairment of renal function, they offer little change to decipher the morphologic lesions. CR is frequently associated with development of proteinuria. Because tubulointerstitial damage is one of the most important adverse effects when CyA is administrated chronically, proteinuria should not be present. The aim of the study was to analyze whether the development of proteinuria could be a useful clinical hallmark to distinguish CR from CyA NT.

Influence of the renin-angiotensin system on epidermal growth factor expression in normal and cyclosporine-treated rat kidney

Epidermal growth factor (EGF) plays an important role in renal tubular regeneration after ischemic injury in kidney. The present study reports the association between the renin-angiotensin system (RAS) and EGF, and the effect of angiotensin II blockade with losartan (LSRT) on EGF expression in an experimental model of chronic cyclosporine (CsA) nephrotoxicity in rats. Two separate experiments were performed. In the first experiment, rats on the normal-salt diet (NSD; 0.3%) or low-salt diet (LSD; 0.05%) were treated with or without LSRT for four weeks. In the second experiment, rats on the NSD or LSD were given vehicle (VH group, olive oil, 1 mg/kg per day) or CsA (15 mg/kg per day) or CsA (15 mg/kg per day) plus LSRT (100 mg/L per day). Renal function, histopathology, TUNEL staining, plasma renin activity (PRA), and the expression of renin and EGF were studied. Normal rats on the LSD showed significantly increased EGF expression (cortex, 2.6-fold; medulla, 1.7-fold) and significantly decreased EGF expression with the LSRT treatment compared with the rats treated with the NSD (cortex, 74.8 vs. 10%; medulla, 22.5 vs. 5%). In contrast, the CsA-treated rats on the LSD had a significantly lower EGF expression (cortex, 98 vs. 53%; medulla, 94 vs. 14%); however, concomitant administration of LSRT increased the EGF expression (cortex, 91- vs. 3.8-fold; medulla, 19- vs. 2.4-fold) compared with the rats on the NSD. In the normal and CsA-treated LSD rats, EGF expression was well correlated with PRA. In addition, EGF expression was well correlated with the interstitial fibrosis score (r = 0.664, P < 0.01) or number of TUNEL-positive cells (r = 0.822, P < 0.01) in CsA-treated LSD rats. These results suggest that angiotensin II blockade with LSRT decreases EGF expression in normal rats on the LSD, but it protects EGF expression in CsA-induced nephrotoxicity. This finding provides a new perspective on the renoprotection of angiotensin II blockade in chronic CsA nephrotoxicity.

Recovery from cyclosporine-associated arteriolopathy in childhood nephrotic syndrome.

Cyclosporine (CS) is well recognized to be effective in the treatment of children with steroid-dependent and steroid-resistant nephrotic syndrome (NS), but its use can result in chronic nephrotoxicity. The histological changes that occur after CS discontinuation are unknown. Therefore, we examined the histological changes [CS-associated arteriolopathy (CAA), tubulointerstitial lesions, and focal glomerular lesions] in renal biopsy specimens after the drug had been discontinued in eight children with idiopathic nephrotic syndrome (NS). These children had been treated with long-term moderate-dose CS and had shown mild-to-moderate chronic CS nephrotoxicity. The degree of CAA improved significantly after CS discontinuation (mean CAA grade from 1.30+/-0.46 to 0.25+/-0.46, P=0.028). CAA disappeared in six of these children after CS discontinuation. However, the tubulointerstitial lesions and the focal glomerular lesions did not change after CS discontinuation. In conclusion, in children with idiopathic NS, CAA is improved by discontinuation of CS, but tubulointerstitial changes and focal glomerular lesions do not regress with drug discontinuation.

Urine macrophage migration inhibitory factor concentrations as a diagnostic tool in human renal allograft rejection.

Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine that is a potent activator of macrophages and T cells. Previous studies have shown that local MIF production is increased in acute renal allograft rejection, suggesting that it may play an important role in the rejection process. To determine if urine and serum MIF concentrations: (1) are increased in acute rejection, and (2) can be used as noninvasive tools to discriminate between acute rejection (AR) and cyclosporine nephrotoxicity (CyA toxicity). In a prospective study of nine renal allograft patients (five acute rejection and four stable), serial urine MIF concentrations were measured by ELISA in the first 14 days after transplantation. In a retrospective study, MIF concentrations in urine and serum were measured in 24 patients who were biopsied for acute renal transplant dysfunction (11 AR, 13 CyA toxicity). Urine and serum MIF were also measured in 23 stable renal transplant patients and 10 normals. MIF was readily detected in the urine of normal healthy controls (106+/-61 pg/micromol creatinine). In the prospective study, the urinary MIF concentration was increased substantially on day 1 posttransplantation and subsequently fell in parallel with the serum creatinine. However, urine MIF increased before episodes of biopsy proven acute rejection. The retrospective study showed that urine MIF concentrations in patients with AR were increased 5-fold compared to normal controls (439+/-313 pg/micromol Cr; P<0.01). In contrast, urine MIF concentrations in CyA toxicity were not significantly different to normal controls (145+/-119 pg/micromol Cr; P=NS). A marked increase in MIF immunostaining was seen in biopsies of AR, but not in CyA toxicity. No significant differences were evident in serum MIF levels between normals and any transplant patient group. These results suggest that measurement of urine MIF concentration may be useful in monitoring renal transplant patients for acute rejection and as a discriminator from cyclosporine nephrotoxicity.

The long-term effect of simultaneous heart and kidney transplantation on native renal function.

It is unclear whether patients with heart failure and renal insufficiency should receive a simultaneous heart and kidney transplant or whether a single heart transplantation is sufficient to restore native renal function. We analyzed the renal plasma flow and glomerular filtration of the native and transplant kidneys in eight patients long term after simultaneous heart and kidney transplantation using a dynamic MAG3 radioisotope scan and serum creatinine determinations. All subjects had been hemodialysis dependent before transplantation. Seven patients suffered from an intrinsic renal disease that were diabetic nephropathy in three cases, small fibrotic kidneys of undetermined origin in two cases, one lupus nephritis, and cyclosporine nephrotoxicity in one patient who had a previous heart transplant. In one patient renal insufficiency was considered to be solely due to renal hypoperfusion because no intrinsic renal disease could be detected. All patients were on cyclosporine-based triple immunosuppression, transplanted for 4 to 10 years, exhibited cardiac ejection fractions of more than 50% and had normal serum creatinine values. Radioisotopic scan showed no function of the native kidneys in all seven patients with intrinsic renal disease but exhibited normal function of the native kidneys as well as the renal transplant in the patient without intrinsic kidney disease before transplantation. These data suggest that a simultaneous heart and kidney transplantation is necessary in patients with cardiomyopathy and renal insufficiency due to primary kidney disease, but not in those with hemodynamically mediated renal failure, even if an immunosuppressive regimen with calcineurin inhibitors is used.