Cyclosporine Nephrotoxicity Research Articles

Acute cyclosporine nephrotoxicity in a patient with oral pemphigus vulgaris and HIV infection on antiretroviral therapy

Acute cyclosporine nephrotoxicity in a patient with oral pemphigus vulgaris and HIV infection on antiretroviral therapy

Chronic Cyclosporine Nephrotoxicity: A Pig Model

Cyclosporine A (CsA) is one of the keystones in immunosuppressive treatment after solid organ transplantation, despite its major side effects such as nephrotoxicity. The chronic nephrotoxic effects of CsA seen in humans have been difficult to reproduce in small-animal models. The aim of the present study was to examine the chronic nephrotoxicity produced by therapeutic dosages of CsA in a pig model. Among 11 Gottingen minipigs included in the study, three died, yielding data from five animals given CsA (10 mg/kg/d, orally) for 6 months, and three controls. Body weight, blood pressure, glomerular filtration rate (GFR) by plasma clearance of 51Cr-ethylenediamine-tetraacetic acid, CsA concentration, serum creatinine, and other values were measured every 5 weeks. Our results showed that the whole blood trough CsA levels were lower in pigs than in humans treated with similar CsA doses. Renal biopsies, which were obtained successfully, except one case of macroscopic hematuria, showed no histological changes in the kidney. No significant increase in serum creatinine or blood pressure was observed. Surprisingly, there was a significant increase in GFR during CsA treatment. We conclude that the pig model displays a hyperfiltration that warrants further investigation.

The Area Under the Concentration-Time Curve Versus Trough and Peak Blood Level Monitoring in Renal Transplant Recipients on Cyclosporine

Objective The area under the concentration-time curve of cyclosporine microemulsion is the best measure of the absorption and beneficial effects in renal transplant recipients. We sought to determine the best method of monitoring cyclosporine levels in these patients. Methods Prospective evaluation of peak cyclosporine blood levels and area under the curve monitoring were performed for 1 year in 65 renal transplant recipients (study group). Cyclosporine trough levels and peak cyclosporine blood levels were correlated with the calculated area under the curve. Cyclosporine trough levels were monitored in equal numbers of matched controls. Results There were no significant differences in the incidence of acute rejection, cyclosporine nephrotoxicity, proteinuria, serum creatinine levels, or graft and patient outcomes between the groups ( P = .1). Peak cyclosporine blood levels guided by calculating the area under the curve were found to be 27% to 32% lower than previously reported. The correlation coefficient was <70% for cyclosporine trough levels ( P < .02) and >90% for peak cyclosporine blood levels ( P < .001) when related to the calculated area under the curve. The calculated area under the curve was approximately 6000 ng/mL/h following transplantation, gradually decreasing to approximately 3000 ng/mL/h at 1 year. Both appeared to the acceptable therapeutic values. Conclusion Calculating the area under the curve using trough and peak blood levels versus using isolated readings for either of these levels alone is the most effective method of monitoring cyclosporine in recipients undergoing renal transplant.

Sirolimus in Combination with Tacrolimus Is Associated with Worse Renal Allograft Survival Compared to Mycophenolate Mofetil Combined with Tacrolimus

Cyclosporine (CsA) nephrotoxicity is enhanced by sirolimus (SRL). Tacrolimus is perceived to be less nephrotoxic than CsA, and therefore, CsA has been largely replaced by tacrolimus (TAC) when calcineurin inhibitors are used with SRL. We analyzed 44 915 adult renal transplants in the Scientific Renal Transplant Registry (SRTR) from 2000 to 2004. Three thousand five hundred twenty-four (7.8%) patients received a baseline immunosuppressive regimen of TAC/SRL, with an inferior overall (log-rank p<0.001) and death-censored graft survival (p<0.001) as compared to TAC/MMF (N=27 007). This effect was confirmed in multivariate Cox models; the adjusted hazard ratio (AHR) for overall graft loss with TAC/SRL was 1.47 (95% CI=1.32, 1.63) and for CsA/SRL 1.38 (95% CI=1.20, 1.59) relative to TAC/MMF. These effects were most apparent in high-risk transplants. Six-month acute rejection rates were low (11.5-12.6%) and not different between groups. In summary, national data indicate that TAC/SRL as compared to TAC/MMF is associated with significantly worse renal allograft survival in all subgroups of patients and, in particular, higher-risk transplants. These results have to be interpreted in the context of the inherent limitations of any retrospective database analysis and evaluated in context with data from prospective clinical trials.

High-dose mizoribine therapy for childhood-onset frequently relapsing steroid-dependent nephrotic syndrome with cyclosporin nephrotoxicity

Cyclosporin A (CsA) is an effective treatment for frequently relapsing steroid-dependent nephrotic syndrome (FR-SDNS), but its use can be complicated by renal toxicity and a high incidence of relapses after withdrawal. We report 9 adolescent patients with childhood-onset FR-SDNS who had been treated with long-term CsA that resulted in moderate-to-severe CsA nephropathy (CsAN). They were treated with high-dose (mean: 10.1 mg/kg per day) mizoribine (MZR) in an attempt to allow weaning of CsA and/or steroid therapy, and reduce the frequency of relapses. Seven out of 9 patients were weaned off CsA by 1-year follow-up, although in the remaining 2 patients, MZR did not show any beneficial effects. Overall, this high-dose MZR therapy results in significant steroid sparing and reduction in relapse rates in our patients. Our experience shows that high-dose MZR therapy in patients with FR-SDNS who are also CsA-dependent appears to be effective in reducing CsA exposure as well as in decreasing the frequency of relapses.

Glomerular and tubular function following orthotopic liver transplantation in children

Since its advent, cyclosporine nephrotoxicity has been a major concern to pediatricians attending to liver transplant recipients. The aims of this study were to examine glomerular and tubular function after orthotopic liver transplantation (OLT) in children, their correlation to CsA, and how they differed according to the underlying disease. Glomerular and tubular function was examined in 28 patients aged 7 months to 14 yr at the time of transplantation (mean 4.0 +/- 3.6), retrospectively examining creatinine clearance, tubular phosphate reabsorption (TRP), calcium/creatinine ratio, sodium excretion fraction, and protein/creatinine ratio. The group with metabolic disease and an underlying tubulopathy was compared with the group with liver disease only. The effect of CsA trough levels and cumulated dose on these indices was examined, as was the effect of antihypertensives on creatinine clearance. Both glomerular and tubular functions improved significantly following liver transplantation. In patients on CsA (n = 21), CrCl decreased significantly at 1 month post-OLT (42.6 +/- 26.6 mL/min/1.73 m(2)) when compared with pretransplantation, and 3, 12 and 60 months post-OLT (p < 0.05). It improved between 12 and 60 months post-OLT (p < 0.05). It was correlated with cyclosporine trough levels (p < 0.03), and with total dose of CsA at 12 months. This was not true for patients on tacrolimus (n = 7). Overall pretransplant TRP was below normal (73.7% +/- 19.6), which was significantly lower than the values at years 2, 3, and 5 post-OLT (p < 0.05), owing mainly to the metabolic group which recovered normal proximal tubular function by the end of the second week post-OLT. Calcium/creatinine ratio was significantly worse in the group with liver disease only (p < 0.01). Protein/creatinine ratio normalized rapidly in both groups. Urinary sodium excretion fraction (FENa) was very abnormal in the early postoperative phase, normalizing thereafter in both groups. Kidney function improved after liver transplantation in patients with and without pre-existing kidney dysfunction. Overall, creatinine clearance was correlated to CsA trough levels suggesting CsA did not have an irreversible 'sclerosing' effect in the medium term. Combined antihypertensive therapy using nifedipine and enalapril may be the optimal choice for patients requiring medical management of their hypertension, although the observed effect on creatinine clearance did not reach statistical significance in this study. Tubular dysfunction is frequent in both groups of patients, pre- and post-transplant, and may contribute to bone mineral density as well as to metabolic disturbances in this population.

Renocortical mRNA expression of vasoactive factors during spironolactone protective effect in chronic cyclosporine nephrotoxicity

We showed that spironolactone reduced structural damage and prevented renal dysfunction in chronic cyclosporine (CsA) nephrotoxicity. These findings evidenced an aldosterone renal vascular effect under this condition. To investigate aldosterone's role in modulating renal vascular tone, renocortical vasoactive pathways mRNA levels in chronic CsA nephrotoxicity as well as spironolactone's effect on renal function in acute CsA nephrotoxicity were evaluated. Two experimental sets were designed. For chronic nephrotoxicity, rats fed with low-sodium diet were divided into groups receiving vehicle, spironolactone (Sp), CsA, and CsA+Sp, for 21 days. Creatinine clearance, survival percentage, and renocortical mRNA levels of pro-renin, angiotensinogen (Ang), angiotensin receptors (AT(1A), AT(1B), and AT(2)), preproendothelin, endothelin receptors (ET(A), ET(B)), cyclooxygenase-2 (COX-2), and adenosine receptors (Ad(1), Ad(2A), Ad(2B), and Ad(3)) were analyzed. For acute nephrotoxicity, similar groups fed with a standard chow diet for 7 days were included. Serum potassium and sodium, glomerular filtration rate (GFR), and renal blood flow (RBF) were determined. In chronic model, CsA produced pro-renin and ET upregulation, altered adenosine receptors expression, and reduced Ang, AT(1A), AT(1B), ET(B), and COX-2 mRNA levels. Spironolactone protective effect in chronic nephrotoxicity was associated with prevention of pro-renin upregulation and increased AT(2), together with ET(B) reduction. In acute nephrotoxicity, spironolactone completely prevented GFR and RBF reduction induced by CsA. Our results suggest that aldosterone contributes to renal vasoconstriction observed in CsA nephrotoxicity and that renoprotection conferred by spironolactone was related to modification of renocortical vasoactive pathways expression, in which pro-renin normalization was the most evident change in chronic nephropathy. Finally, our data point to spironolactone as a potential treatment to reduce CsA nephrotoxicity in transplant patients.

Cyclosporine - a treatment and a rare complication: Raynaud's phenomenon

Cyclosporine - a treatment and a rare complication: Raynaud's phenomenon

Cyclosporine decreases prostaglandin E2 production in mouse medullary thick ascending limb cultured cells

Intrarenal vasoconstriction is thought to be the major pathogenesis of cyclosporine (CsA) nephrotoxicity. Nitric oxide (NO) and prostaglandin E2 (PGE2) are two of the major intrarenal vasodilators, which protect kidney from ischemia. CsA inhibited NO production in renal epithelial cells. The interaction between CsA and intrarenal PGE2 and NO production is still unclear. The aim of the study is to evaluate the interaction of CsA with intrarenal PGE2 and NO production in renal epithelial cells. Models of cultured mouse thick ascending limb (TAL) cells are chosen to perform the experiments, as TAL cells are the major site of intrarenal PGE2 production and target of CsA nephrotoxicity. We investigated the PGE2 production by enzyme-linked immunosorbent assay, and cyclooxygenase (COX-1 and COX-2) mRNA expression by RT-PCR in cultured cells treated with or without CsA. TAL cells maintained the main characteristics of their parental cells. TAL cells produce PGE2 mainly by COX-1 in steady state and by COX-2 in stimulated state by lipopolysaccharide (LPS). CsA (100 ng/ml) significantly reduced the PGE2 production up to 43% in TAL cells in LPS stimulated status (control versus CsA: 375.1 +/- 15.5 vs. 187.2 +/- 12.2 nm/mg protein, n = 7, P < 0.001). The effects were dose-dependent. The mRNA expression of COX1 is not affected and COX-2 is decreased in CsA-treated TAL cells. NO donor could prevent the inhibitory effects of CsA. We concluded that CsA decreased intrarenal PGE2 production in stimulated status mainly by decreasing COX-2 expression. NO might play a role in the CsA effect. The results suggested the role possible of PGE2 in CsA nephrotoxicity.

Cyclosporine Prolongs Delayed Graft Function in Kidney Transplantation: Are Rabbit Anti-Human Thymocyte Globulins the Answer?

Background: Cyclosporine (CsA) nephrotoxicity may prolong duration of anuria in renal transplant patients with delayed graft function (DGF). Thus, many Transplant Centers tend to delay CsA treatment in order to accelerate renal function recovery. Methods: In this single-center, retrospective analysis we compared the outcomes of 40 renal transplant patients with DGF given a CsA-based (n = 17) regimen since the day of transplant or a CsA-sparing regimen (n = 23) based on early treatment with rabbit anti-human thymocyte globulin (RATG) and delayed CsA administration. We studied all patients with DGF who received a first or second graft at the Bergamo Transplant Center from January 1992 to March 2000. Results: Patients given RATG as compared to those on CsA had significantly shorter duration of anuria (11.0 ± 5.6 vs. 19.6 ± 8.9 days; p < 0.005) and of initial hospitalization (17.4 ± 4.3 vs. 27.4 ± 10.4 days; p < 0.001). Throughout the whole study period, 4 patients on RATG as compared to 6 on CsA had an acute rejection episode (p > 0.05). However, no patient on RATG as compared to 4 on CsA had an acute rejection during the anuria period (p < 0.05). Costs including hospitalization, dialysis treatment and study drugs were significantly lower in RATG than in CsA patients (EUR 29,944 ± 7,281 vs. 36,795 ± 13,656; p < 0.05). Conclusions: In renal transplant patients with DGF, early RATG treatment with delayed CsA administration accelerated renal function recovery and patient discharge, prevented occult rejections throughout the anuria period and significantly decreased the treatment costs.

Comparison between swallowing and chewing of garlic on levels of serum lipids, cyclosporine, creatinine and lipid peroxidation in Renal Transplant Recipients

Hyperlipidemia and increased degree of oxidative stress are among the important risk factors for Atherosclerosis in renal transplant recipients (RTR). The Medical treatment of hyperlipidemia in RTR because of drugs side effects has been problematic, therefore alternative methods such as using of Garlic as an effective material in cholesterol lowering and inhibition of LDL Oxidation has been noted. For evaluation of garlic effect on RTR, 50 renal transplant patients with stable renal function were selected and divided into 2 groups. They took one clove of garlic (1 gr) by chewing or swallowing for two months, after one month wash-out period, they took garlic by the other route. Results indicated that although lipid profile, BUN, Cr, serum levels of cyclosporine and diastolic blood pressure did not change, Systolic blood pressure decreased from138.2 to 132.8 mmHg (p=0.001) and Malondialdehyde (MDA) decreased from 2.4 to1.7 nmol/ml (p=0.009) by swallowing route, Cholesterol decreased from 205.1 to 195.3 mg/dl (p=0.03), triglyceride decreased from 195.7 to 174.8 mg/dl (p=0.008), MDA decreased from 2.5 to 1.6 nmol/ml (p=0.001), systolic blood pressure decreased from 137.5 to 129.8 mmHg (p=0.001), diastolic blood pressure decreased from 84.6 to 77.6 mmHg (p=0.001) and Cr decreased from 1.51 to 1.44 mg/dl (p=0.03) by chewing route too. However HDL, LDL and cyclosporine serum levels had no significant differences by both of swallowing and chewing routes. We conclude that undamaged garlic (swallowed) had no lowering effect on lipid level of serum. But Crushed garlic (chewed) reduces cholesterol, triglyceride, MDA and blood pressure. Additionally creatinine reduced without notable decrease in cyclosporine serum levels may be due to cyclosporine nephrotoxicity ameliorating effect of garlic.

Magnesium Supplementation Prevents Chronic Cyclosporine Nephrotoxicity via Adjusting Nitric Oxide Synthase Activity

Introduction Nitric oxide synthase (NOS) is a protective factor for chronic cyclosporine nephrotoxicity by virtue of adjusting the production of nitric oxide (NO). The aim of this study was to explore the role of NOS in the effect of magnesium supplementation to prevent chronic cyclosporine nephrotoxicity. Methods Rats maintained on a low-salt diet were divided into three groups: normal controls, cyclosporine group (CsA 15 mg · kg −1 · d −1 subcutaneously) and CsA + Mg 2+ group (CsA subcutaneously and dietary supplementation with 0.6% Mg enriched by MgCl 2). On day 28, plasma Mg 2+, plasma creatinine, NOS activity, and NO content in renal tissue were examined. The renal expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in kidneys was determined by an immunohistochemistry technique. The lesions of chronic cyclosporine nephrotoxicity were identified by HE and PAS stains as well as electron microscope. Results After 28 days of CsA administration, characteristic histological lesions of chronic cyclosporine nephotoxicity were observed, including arteriolopathy, tubular atrophy and interstitial fibrosis. Giant mitochondria and microcalcifications were observed by electron microscopy. Simultaneously, constitutive nitric oxide synthase (cNOS) activity in kidneys was increased, but NO content did not increase correspondingly ( P < .05) compared with normal controls. Dietary supplementation with Mg 2+ ameliorated the CsA-induced histological lesions. cNOS activity was decreased to normal levels and NOS was increased ( P < .05) compared with animals that only received CsA. CsA and magnesium supplementation did not change iNOS activity. Conclusions Dietary supplementation with Mg 2+ seems to improve renal function and almost abolish CsA-induced histological lesions via altering the abnormal activation of cNOS in this model.

Editorial Comment: Reduction in Calcineurin Inhibitor Exposure and Maintenance of Effective Immunosuppression: Clinical Experience with Everolimus (Certican)

Editorial Comment: Reduction in Calcineurin Inhibitor Exposure and Maintenance of Effective Immunosuppression: Clinical Experience with Everolimus (Certican)

Low serum magnesium is associated with decreased graft survival in patients with chronic cyclosporin nephrotoxicity

Hypomagnesaemia is a common side effect of cyclosporin A (CsA) therapy. Animal studies suggest that magnesium (Mg) supplementation inhibits chronic CsA nephropathy. To determine if low Mg levels correlate with true CsA-induced nephrotoxicity in humans, we examined kidney transplant biopsy records at our centre for all transplant biopsies performed between 1990 and 2002. We simultaneously reviewed the medical records to determine whether serum Mg levels were checked at the time of biopsy. Those individuals with histologically proven CsA nephrotoxicity were studied. Serum total Mg levels were available for 320 patients, 60 of whom were diagnosed with chronic CsA-mediated nephropathy. Patients were divided in two groups, a low Mg [n = 29, 1.8 (1.67-1.9) mg/dl or 0.74 (0.68-0.78) mmol/l] and a normal Mg group [n = 31, 2.2 (2.0-2.4) mg/dl or 0.9 (0.82-0.98) mmol/l, P<0.05] based on the median Mg level in the entire cohort (2 mg/dl or 0.82 mmol/l). Both groups were analysed for disease progression and graft loss using the slope of creatinine clearance (CCR) and multivariate analyses. Although the CCR at the time of biopsy was greater in the low Mg group [44.3 (36.3-64.3) ml/min vs 37.8 (25.2-47.3) ml/min, P<0.05), the decline in graft function was faster in this group (-8.9+/-3.5 vs 1+/-2.7 ml/min/year; P = 0.02) compared with the normal Mg cohort. Using Cox proportional hazards analyses, the adjusted graft survival was significantly reduced in the low Mg group 5 years after biopsy. Our study demonstrates that low serum Mg levels were associated with a faster rate of decline in kidney allograft function and increased rates of graft loss in renal transplant recipients with chronic CsA nephropathy. This suggests that hypomagnesaemia could potentiate CsA-mediated nephropathy.

ABCB1 Genotype of the Donor but Not of the Recipient Is a Major Risk Factor for Cyclosporine-Related Nephrotoxicity after Renal Transplantation

Cyclosporine (CsA) nephrotoxicity is a severe complication in organ transplantation because it leads to impaired renal function and chronic allograft nephropathy, which is a major predictor of graft loss. Animal models and in vivo studies indicate that the transmembrane efflux pump P-glycoprotein contributes substantially to CsA nephrotoxicity. It was hypothesized that the TT genotype at the ABCB1 3435C-->T polymorphism, which is associated with decreased expression of P-glycoprotein in renal tissue, is a risk factor for developing CsA nephrotoxicity. In a case-control study, 18 of 97 patients developed CsA nephrotoxicity and showed complete recovery of renal function in all cases when switched to a calcineurin inhibitor-free regimen. Both recipients and donors were genotyped for ABCB1 polymorphisms at the positions 3435C-->T and 2677G-->T/A. For controlling for population stratification, two additional polymorphisms, CYP2D6*4 and CYP3A5*3, with intermediate allelic frequencies were studied. The P-glycoprotein low expressor genotype 3435TT only of renal organ donors but not of the recipients was overrepresented in patients with CsA nephrotoxicity as compared with patients without toxicity (chi2 = 10.5; P = 0.005). CsA dosage, trough levels, and the concentration per dose ratio were not different between the patient groups. In a multivariate model that included several other nongenetic covariates, only the donor's ABCB1 3435TT genotype was strongly associated with CsA nephrotoxicity (odds ratio, 13.4; 95% confidence interval, 1.2 to 148; P = 0.034). A dominant role of the donor's ABCB1 genotype was identified for development of CsA nephrotoxicity. This suggests that P-glycoprotein is an important factor in CsA nephrotoxicity.

Renal function outcome in pediatric liver transplant recipients

The orthotopic liver transplantation (OLT) allows survival of children followed for severe hepatic injury, provided that the immunosuppressive treatment is prolonged. The nephrotoxicity of cyclosporine predicts the long-term outcome of the adult patients receiving a liver transplant. The aim of this study was to determine the long-term outcome of renal function in children receiving OLT. This study included 12 children, with a median for age of 7.1 yr (2-15 yr) at the time of OLT. The duration of follow-up was at least 4 yr, being 7 yr in 10 patients and more than 10 yr in seven. Renal function was evaluated with the serum level of creatinine, calculated glomerular filtration rate (cGFR), and measurement of glomerular filtration rate using chrome 51 ethylenediaminetetraacetate ((51)Cr EDTA) clearance performed at least once during follow-up. The doses and the serum concentrations (C(0)) of cyclosporine were reported at each study time. The cGFR decreased significantly 2 yr after the OLT [median (range): 106 mL/min/1.73 m(2) (71-150) at the time of OLT vs. 85 mL/min/1.73 m(2) (57-128) 2 yr after the OLT, p = 0.03], and decreased again between 7 and 10 yr after OLT [median (range): 99 mL/min/1.73 m(2) (76-125) 7 yr after OLT vs. 81 mL/min/1.73 m(2) (66-140) 10 yr after OLT, p = 0.04]. Six patients developed chronic renal failure (cGFR from 57 to 80 mL/min/1.73 m(2)) 2 yr after OLT associated with high doses of cyclosporine [median (range): 8.8 mg/kg/day (3.5-13)]. The cGFR overestimated renal function by 16% compared with the isotopic measurement of GFR (p = 0.03). Using the (51)Cr EDTA measurement, six of seven patients followed up more than 10 yr after OLT presented mild (n = 3) or moderate (n = 3) chronic renal failure. In our study, the majority of OLT recipients developed a chronic renal failure 10 yr after transplantation. Cyclosporine seems to be the most important factor responsible for the impairment of renal function. The use of the mycophenolate mofetil, a new immunosuppressive agent, allowing a reduction in the dose of cyclosporine, could minimize renal dysfunction. While awaiting the results of a prospective long-term study, close drug monitoring is advised.

Cyclosporine-Sparing Effect of Basiliximab in Renal Transplant Recipients With Mycophenolate Mofetil

Basiliximab added to a maintenance regimen consisting of cyclosporine microemulsion and mycophenolate mofetil was studied for its effectiveness in allowing early steroid withdrawal in renal transplantion. Furthermore, the cyclosporine-sparing effects between groups with and without basiliximab induction therapy were compared. Patients Between September 2001 and June 2003, 90 patients underwent renal transplants with cyclosporine-based immunosuppression, namely, cyclosporine, mycophenolate mofetil, and methylprednisolone, (group 1; n = 25). During the latter half of the study basiliximab was administered during the induction phase (group 2; n = 65). In group 2, steroids were completely withdrawn on postoperative day 14 in 57 patients. Results The incidence of acute rejection was significantly higher among group 1 patients ( P = .005). The incidence of steroid-resistant rejection in group 1 patients was significantly higher ( P = .025). At each time point cyclosporine levels in group 1 patients were significantly higher ( P < .01). The incidence of infection was comparable between the groups. Patient and graft survival rates in group 1 were 100% and 100%; in group 2, they were 99% and 99%, respectively. In group 2, steroids were discontinued in 57 patients with permanent withdrawal achieved in 32 patients (56%). Conclusion The use of basiliximab, together with mycophenolate mofetil allowed for a significant reduction in the cyclosporine dose without increasing the risk of acute rejection. Although further follow-up is necessary to confirm the effect, this regimen may attenuate cyclosporine nephrotoxicity thereby affecting the long-term outcomes of renal transplantation.

Immunité cellulaire et traitement immunosuppresseur du syndrome néphrotique idiopathique corticosensible

Steroid sensitive idiopathic nephrotic syndrome is a T-cell disorder characterized by a functional renal impairment. Concluding a still relevant demonstration involving cellular immunity in the pathogenesis of the disease, R. Shalhoub in 1974 suggested a “special role for the thymus” based on the efficiency of steroids and alkylating agents, dramatic recoveries following measles, sensibility to bacterial infection due to a lack of cooperation between T and B cell and association to Hodgkin disease. As a matter of fact, the selected drugs based on medical empirism somehow enhance thymocytes apoptosis and negative selection of T cell, except cyclosporin. Steroids have been the first historical treatment of idiopathic nephrotic syndrome and have steadily been the first-line treatment for 50 years. Their unavoidable ability to induce rapid recovery of proteinuria and long-lasting or definite remission are dependent to a strict compliance to treatment. Indications of steroids-sparing treatments are not that clearcut in patients with steroids intoxication. Objectively, efficiency of levamisole and cyclophosphamide are much more limited than previously reported and cyclosporin nephrotoxicity might severely impair renal function following long-lasting treatment as well as it may paradoxically increase the activity of the disease. An alternate strategy to those currently adopted would use cyclosporin as the first-line steroids-sparing treatment during a very limited period, awaiting favourable ageing of patients and natural dampening activity of the disease to a full efficiency of alkylating agents. Compared to cyclophosphamide and cyclosporin, the relative safety of levamisole is encouraging to a more frequent uses. Its association to a full dose of prednisone in the treatment of the inaugural episode should be investigated. According to the limitations of those therapies, emerging drugs as mycophenolate might be worthwhile in the treatment of nephrotic patients.

Effect of molsidomine and l-arginine in cyclosporine nephrotoxicity: role of nitric oxide

Cyclosporine A (CsA) is a potent and effective immunosuppressive agent, but its action is frequently accompanied by severe renal toxicity. To determine if the renal alterations are mediated directly by cyclosporine or by secondary homodynamic alterations induced by cyclosporine, we evaluated if L-arginine and a nitric oxide donor, molsidomine could prevent these alterations. Eight groups of rats were employed in this study, group 1 served as control, group 2 rats were treated with CsA (20 mg/kg, s.c. for 21 days), group 3 received CsA along with L-arginine (125 mg/kg in drinking water concurrently with CsA), groups 4 and 5 received CsA along with molsidomine (5 and 10 mg/kg, p.o. 24 h before and 21 days concurrently with CsA), group 6 received CsA along with L-arginine (125 mg/l in drinking water concurrently with CsA) and L-NAME (10 mg/kg), groups 7 and 8 received L-NAME (10 mg/kg) along with CsA and molsidomine (5 and 10 mg/kg), respectively. Renal function was assessed by measuring serum creatinine, blood urea nitrogen, creatinine and urea clearance. Tissue and urine nitrite and nitrate levels were measured to estimate the total nitric oxide levels. The renal oxidative stress was measured by renal malondialdehyde levels, reduced glutathione levels and by enzymatic activity of catalase and superoxide dismutase. Renal morphological alterations were assessed by histopathological examination. CsA administration for 21 days resulted in a marked renal oxidative stress, significantly deranged the renal functions as well as renal morphology. Treatment with L-arginine as well as with molsidomine significantly improved the renal dysfunction; tissue and urine total nitric oxide levels, renal oxidative stress and prevented the alterations in renal morphology. This protection against CsA nephrotoxicity was attenuated by treatment with L-NAME, clearly indicating that NO plays a pivotal role in renoprotective effect of L-arginine and molsidomine against cyclosporine nephrotoxicity.

Initial experience with sirolimus and mycophenolate mofetil for renal rescue from cyclosporine nephrotoxicity after heart transplantation

Calcineurin inhibitors (CNIs) have become the cornerstone of immunosuppressive regimens following heart transplantation, but their use is associated with nephrotoxicity. We evaluated a CNI elimination protocol in 14 patients with renal impairment at 48.3 ± 36.0 months after heart transplantation. The mean serum creatinine was 321 ± 107 μmol/L; cyclosporine ( n = 13) or tacrolimus ( n = 1) was discontinued with sirolimus commenced immediately, initially aiming for a target trough level of 16 (12 to 20) ng/mL. If patients were not receiving mycophenolate (MMF) this was initiated at 1 g bid. The transfer period was covered with a tapering course of corticosteroids. In addition to monitoring clinical status, hematology, biochemistry, and sirolimus levels, graft function was assessed by echocardiography, ECG, and, where indicated, endomyocardial biopsy. Renal function improved in 12 patients (with 6 having a greater than 40% decrease in serum creatinine), remained unchanged in 1, and deteriorated in 1. Two patients who were converted at 15 and 139 months after transplantation experienced grade 3A rejection. One patient experienced a fall in ejection fraction without histologic evidence of rejection. Sirolimus was discontinued in three patients because of side effects: bone marrow suppression, presumed lymphocytic pneumonitis, and generalized acneform rash complicated by an axillary abcess; 50% of patients continue on sirolimus. In conclusion, withdrawal of CNIs after heart transplantation resulted in an improvement in renal function in most patients: 43% experienced a substantial improvement. CNI elimination protocols need to be refined to reduce the risk of breakthrough rejection and to minimize side effects while protecting renal function after heart transplantation.