Acute CsA Research Articles

Accidental Overdose of Oral Cyclosporine in Haematopoietic Stem Cell Transplantation: A Case Report and Literature Review.

A 26-year-old woman developed symptoms of acute toxicity during cyclosporine (CsA) therapy for graft-versus-host disease prophylaxis. The standard regimen included CsA in a dose of 1.5 mg/kg (120 mg) every 12 h, but, as a medication error, she received a high dose of 500 mg of oral CsA. After 2 h, she developed nausea and vomiting and, subsequently, flushing, chest tightness, tremor and vertigo. Laboratory and clinical examinations revealed high blood CsA concentrations (1000 ng/mL after 12 h) with a mild increase in blood pressure. Therefore, the patient was diagnosed with an acute CsA overdose. Before confirmation of the overdose by measurement of drug concentrations, the second dose was administered at its routine time because of uncertainty about the aetiology of the symptoms. The third dose was withheld, and the patient was monitored closely for clinical and laboratory presentations until the time when the abnormalities were relieved. CsA administration was then resumed with the correct prescription. The patient was discharged with successful engraftment and normal biochemical laboratory results after 1 month. Evaluation with the Naranjo assessment score indicated a probable relationship between the patient’s symptoms and overdosage with the suspected drug. Currently, detailed presentations of acute CsA toxicity cases due to overdose are limited in the medical literature. Evaluation of the patient’s medical and laboratory records, with cooperation of all responsible clinical staff, along with a review of the literature, were very helpful in discovery of the toxicity incident. Vigilance of health care providers with regard to medication errors and early detection of toxicity symptoms can decrease CsA-related morbidity and mortality in the future.

Cyclosporine-Induced Tubular Vacuolization: The Role of Bip/Grp78

Cyclosporine (CsA) nephrotoxicity shows characteristic tubular vacuolization (TV) which is endoplasmic reticulum (ER) in origin. However, the cellular events of CsA-induced TV and CsA-induced ER remained unclear. The aim of the present study was to study the nature of TV and the correlation to ER stress. Using proximal tubule NRK-52E cells in vitro and an in vivo model of acute CsA nephrotoxicity, we confirmed that CsA-induced TV was ER in origin and potentially reversible. Our results showed that CsA-induced ER stress and involved ER integrated stress response-related proteins (Bip/Grp78, ATF6, IRE1 and CHOP) but not cytoplasmic ER stress-related chaperones (HSP70, HSP40, HSP27, HSP90 and HSP60). Importantly, Bip/Grp78 was overexpressed on the membrane of TV and suppression of Bip/Grp78 blocked TV formation. In addition, suppression of Bip/Grp78-enhanced CsA-induced cell death and CsA-induced TV formation and Bip/Grp78 overexpression had a characteristic striped pattern in the tubulointerstitium. In summary, we demonstrate that CsA-induced TV was a potentially reversible process in which Bip/Grp78 overexpression is essential for TV formation. It is possible that Bip/Grp78 expression and TV formation may be involved in cellular defense mechanism against CsA nephrotoxicity.

Annexin A1 protein attenuates cyclosporine-induced renal hemodynamics changes and macrophage infiltration in rats

Cyclosporine (CsA) remains an important immunosuppressant for transplantation and for treatment of autoimmune diseases. The most troublesome side effect of CsA is renal injury. Acute CsA-induced nephrotoxicity is characterized by reduced renal blood flow (RBF) and glomerular filtration rate (GFR) due to afferent arteriole vasoconstriction. Annexin A1 (ANXA1) is a potent anti-inflammatory protein with protective effect in renal ischemia/reperfusion injury. Here we study the effects of ANXA1 treatment in an experimental model of acute CsA nephrotoxicity. Salt-depleted rats were randomized to treatment with VH (vehicles 1mL/kg body weight/day), ANXA1 (Ac2-26 peptide 1mg/kg body weight/day intraperitoneally), CsA (20mg/kg body weight/day subcutaneously) and CsA+ANXA1 (combination) for seven days. We compared renal function and hemodynamics, renal histopathology, renal tissue macrophage infiltration and renal ANXA1 expression between the four groups. CsA significantly impaired GFR and RBF, caused tubular dilation and macrophage infiltration and increased ANXA1 renal tissue expression. Treatment with ANXA1 attenuated CSA-induced hemodynamic changes, tubular injury and macrophage infiltration. ANXA1 treatment attenuated renal hemodynamic injury and inflammation in an acute CsA nephrotoxicity model.

Non-Invasive Imaging of Acute Renal Allograft Rejection in Rats Using Small Animal 18F-FDG-PET

BackgroundAt present, renal grafts are the most common solid organ transplants world-wide. Given the importance of renal transplantation and the limitation of available donor kidneys, detailed analysis of factors that affect transplant survival are important. Despite the introduction of new and effective immunosuppressive drugs, acute cellular graft rejection (AR) is still a major risk for graft survival. Nowadays, AR can only be definitively by renal biopsy. However, biopsies carry a risk of renal transplant injury and loss. Most important, they can not be performed in patients taking anticoagulant drugs.Methodology/Principal FindingsWe present a non-invasive, entirely image-based method to assess AR in an allogeneic rat renal transplantation model using small animal positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG). 3 h after i.v. injection of 30 MBq FDG into adult uni-nephrectomized, allogeneically transplanted rats, tissue radioactivity of renal parenchyma was assessed in vivo by a small animal PET-scanner (post operative day (POD) 1,2,4, and 7) and post mortem dissection. The mean radioactivity (cps/mm3 tissue) as well as the percent injected dose (%ID) was compared between graft and native reference kidney. Results were confirmed by histological and autoradiographic analysis. Healthy rats, rats with acute CSA nephrotoxicity, with acute tubular necrosis, and syngeneically transplanted rats served as controls. FDG-uptake was significantly elevated only in allogeneic grafts from POD 1 on when compared to the native kidney (%ID graft POD 1: 0.54±0.06; POD 2: 0.58±0.12; POD 4: 0.81±0.06; POD 7: 0.77±0.1; CTR: 0.22±0.01, n = 3–28). Renal FDG-uptake in vivo correlated with the results obtained by micro-autoradiography and the degree of inflammatory infiltrates observed in histology.Conclusions/SignificanceWe propose that graft FDG-PET imaging is a new option to non-invasively, specifically, early detect, and follow-up acute renal rejection. This method is potentially useful to improve post-transplant rejection monitoring.

Analysis of granzyme B mRNA and perforin mRNA levels in urine for renal transplantation patients with de-layed graft function

Objective To explore the clinical value of the level of granzyme B and perforin mRNA in urine for the diagnosis of renal transplantation patients with delayed graft function (DGF). Methods Twenty-four cases of renal transplantation patients with DGF were included in this study. Seventy-three u-rine specimens were obtained from these patients who received graft biopsies. Among the 24 cases, ureteral obstruction occurred in 2 cases, vascular thrombosis in 1 case, acute CsA intoxication in 3 cases, acute tubu-lar necrosis (ATN) in 7 cases, ATN complicating borderline change in 2 cases, ATN complicating acute re-jection (AR) in 3 cases, AR in 6 cases. Total RNA was isolated from the urinary cells. Messenger RNA (mRNA) encoding the cytotoxic proteins perforin and granzyme B gene were measured with the quantitative polymerase-chain-reaction assay-(RT-PCR). SPSS13.0 software was used for data analysis. Levels of mRNA were log-transformed before analysis. Results The levels of perforin and granzyme B mRNA in u-rine among the ureteral obstruction group, vascular thrombosis group, acute CsA intoxication group and ATN group were very low. There was no significant difference among these groups (P>0.05). However,among the ATN complicating borderline change group 1.22, 0. 97 fg/μg, ATN complicating AR group (1.20±0.39), (1.07±0.30)fg/μg, and AR group(11.13±0. 33), (1.01±0.19)fg/μg, the levels were increased significantly(P<0.001). Conclusion Measurement of mRNA encoding the cytotoxic proteins perforin and granzyme B gene in urinary cells in renal transplantation patients with DGF could be helpful to etiological diagnosis of DGF, and might be used as an index for the appropriate management of the borderline change. Key words: Kidney transplantation; Delayed graft function; Perforin; Granzyme B

Renal Transplantation in Primary Focal Segmental Glomerulosclerosis Using a Tolerance Induction Protocol

We report our experience of transplantation using Ahmedabad Tolerance Induction Protocol (ATIP) in primary focal segmental glomerulosclerosis (FSGS) known to recur leading to graft loss. Methods Twenty-four primary FSGS patients were transplanted at our centre from 1997 to 2007. The 15 ATIP patients using hematopoietic stem cell transplantation (HSCT) under minimum nonmyeloablative conditioning was performed using living donors. Recipent mean age was 28 years and mean follow-up is 4.4 years. In contrast, nine control subjects of mean age 36 years had 4.8-year follow-up and received standard immunosuppression. Our Institutional Ethics Committee approved ATIP. Donor-recipient HLA match was similar. Results Mean serum creatinine (SCr) values of the 12 ATIP patients who were doing well at 1, 3, 5 years and at present were: 1.62, 1.48, 1.6, and 1.92 mg%, respectively, on cyclosporine (1.5 ± 1 mg/kg per day) and prednisone (7.5 mg/day). No recurrence was observed. One patient died at 19 months posttransplant following relentless acute rejection; two patients with unrelated grafts were lost due to acute rejection at 11 weeks and 2 years posttransplant. Two graft biopsies performed at 1 and 2 years posttransplant revealed unremarkable histology, seven showed acute CsA toxicity at 1 year posttransplant. No chronic changes were noted. Among control group B, with 5 of 9 functioning grafts, two were obtained from deceased and three from unrelated donors with mean SCr values at 1, 3, and 4 years as well as present, were 1.77, 1.65, 1.6, and 1.53 mg%, respectively. Four patients displayed recurrences at 8 days, 1 month, and 1 and 2 years posttransplant. One patient died at 1 year posttransplant; one patient received a subsequent cadaver donor graft and two are on maintenance dialysis. Conclusion Transplantation under ATIP seemed to mitigate recurrence of primary FSGS.

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.

Nephrotoxic aspects of cyclosporine

Over the last 20 years cyclosporine (CsA) has improved the survival of kidney, heart, and liver transplants. However, with increasing use, evidence has accumulated that CsA therapy carries a variety of side effects, the most important being renal toxicity. CsA can lead to a wide spectrum of renal function impairments, including a marked and rapidly reversible decrease in renal hemodynamics (acute CsA nephrotoxicity), and a chronic form of renal damage that potentially progress irreversibly to end-stage renal disease (chronic CsA nephrotoxicity). All these manifestations are the consequence of the drug toxic effects on renal vessels and the tubulointerstitium. A proper diagnosis of CsA toxicity at early stages, the combination of low CsA doses with non-nephrotoxic immunosuppressants, and the development of more feasible strategies to monitor daily CsA exposure may contribute to a better CsA management, improve quality of life of transplant recipients, and prolong graft survival.

Differentiation between acute cyclosporine nephrotoxicity and acute tubular necrosis using enalaprilat renal scintigraphy in rats.

Acute cyclosporine (CsA) nephrotoxicity cannot be easily differentiated from other renal parenchymal complications, such as acute tubular necrosis (ATN), that cause renal function impairment at the early posttransplantation period. The purpose of this study was to differentiate acute CsA nephrotoxicity from ATN using enalaprilat renal scintigraphy in rats. Twenty-six rats were divided into 4 experimental groups: CsA group, who were treated with CsA (50 mg/kg/d) for 2 days; ATN group, who received clamping of both renal arteries for 45 minutes; vehicle group, who were treated with olive oil (1 mL/kg/d) for 2 days; and sham-operated group, who received the same surgical procedure as ATN group without clamping of renal arteries. The baseline study was performed with 300 microCi of technetium-99m diethylenetriaminepentaacetic acid and enalaprilat scintigraphy with 2 mCi of technetium-99m diethylenetriaminepentaacetic acid 5 minutes after intravenous enalaprilat injection (30 microg/kg). The changes of renogram grade and the renal function indices such as T(max), T(1/2), residual cortical activity, and mean transit time between 2 studies were analyzed. Immediately after renal scintigraphy, blood urea nitrogen and serum creatinine levels were measured and renal tissues stained by periodic acid Schiff reaction were examined in each group. Blood urea nitrogen and serum creatinine levels in the CsA and ATN groups were higher than their control groups (P < 0.05). Histologic study revealed severe ischemic necrosis of tubular epithelium in ATN group, but the other groups remained with essentially normal morphology. After enalaprilat injection, renal function indices became improved in CsA group, whereas they deteriorated in ATN group. The renogram grade was decreased in CsA group and increased or unchanged in ATN group after enalaprilat injection. The T(max), residual cortical activity, and mean transit time ratio were statistically different between the 2 groups on enalaprilat study (P < 0.05). These results suggest that enalaprilat renal scintigraphy could be used clinically in differentiating acute CsA nephrotoxicity from ATN after renal transplantation.

A systematic examination of estimates of cyclosporine area under the curve in renal transplant recipients.

A systematic examination of estimates of cyclosporine area under the curve in renal transplant recipients.

Coadministration of ketoconazole and cyclosporine for kidney transplant recipients: Long-term follow-up and study of metabolic consequences

In a prospective randomized study including 100 kidney transplant recipients, we previously reported on the safety and financial benefits of the coadministration of ketoconazole (keto) to cyclosporine (CsA)-treated kidney transplant recipients. In this study, we report on the long-term follow-up of these patients and their control group, as well as possible metabolic consequences of this drug combination. Evaluation of 51 keto-treated patients and their control group (49 patients) included graft function, lipogram, fasting blood glucose, liver function tests, serum calcium, phosphorus, and radiological and histopathologic assessments. Follow-up of these patients for 54 months showed that the CsA dose reduction was 72.9% at 12 months, decreased to 69.3% at the last follow-up. We also found that the mean keto dose required for CsA dose reduction decreased to 82.8 ± 24.1 mg/d compared with the starting dose (100 mg/d). Diagnosis of acute rejection episodes was similar in both groups. However, in the control group, rejection episodes were more recurrent, with poorer response to treatment. Acute CsA nephrotoxicity was more common in the keto group, but this was encountered more at keto induction and was rapidly reversed on further reduction of CsA doses. Chronic graft dysfunction was statistically significantly less in the keto group during the first year. However, by the end of the study, the difference was not statistically significant. In this study, hepatotoxicity was similar in the two groups. On studying the metabolic consequences, we found that serum cholesterol, low-density lipoprotein, and triglyceride levels were lower in the keto group. Bone mineral contents in both groups were less than the mean values for age- and sex-matched healthy controls. From this study, we conclude that long-term use of low-dose keto in CsA-treated kidney transplant recipients is safe and cost-saving and may induce better graft function. Bone mineral contents, vitamin D blood levels, and lipid profiles are not affected by long-term keto coadministration in CsA-treated kidney transplant recipients.

Coadministration of ketoconazole and cyclosporine for kidney transplant recipients: Long-term follow-up and study of metabolic consequences

In a prospective randomized study including 100 kidney transplant recipients, we previously reported on the safety and financial benefits of the coadministration of ketoconazole (keto) to cyclosporine (CsA)-treated kidney transplant recipients. In this study, we report on the long-term follow-up of these patients and their control group, as well as possible metabolic consequences of this drug combination. Evaluation of 51 keto-treated patients and their control group (49 patients) included graft function, lipogram, fasting blood glucose, liver function tests, serum calcium, phosphorus, and radiological and histopathologic assessments. Follow-up of these patients for 54 months showed that the CsA dose reduction was 72.9% at 12 months, decreased to 69.3% at the last follow-up. We also found that the mean keto dose required for CsA dose reduction decreased to 82.8 ± 24.1 mg/d compared with the starting dose (100 mg/d). Diagnosis of acute rejection episodes was similar in both groups. However, in the control group, rejection episodes were more recurrent, with poorer response to treatment. Acute CsA nephrotoxicity was more common in the keto group, but this was encountered more at keto induction and was rapidly reversed on further reduction of CsA doses. Chronic graft dysfunction was statistically significantly less in the keto group during the first year. However, by the end of the study, the difference was not statistically significant. In this study, hepatotoxicity was similar in the two groups. On studying the metabolic consequences, we found that serum cholesterol, low-density lipoprotein, and triglyceride levels were lower in the keto group. Bone mineral contents in both groups were less than the mean values for age- and sex-matched healthy controls. From this study, we conclude that long-term use of low-dose keto in CsA-treated kidney transplant recipients is safe and cost-saving and may induce better graft function. Bone mineral contents, vitamin D blood levels, and lipid profiles are not affected by long-term keto coadministration in CsA-treated kidney transplant recipients.

Conversion to rapamycin immunosuppression in renal transplant recipients: report of an initial experience.

The aim of this study is to evaluate the effects of RAPA conversion in patients undergoing cyclosporine (CsA) or tacrolimus (Tac) toxicity. Twenty renal transplant recipients were switched to fixed dose rapamycin (RAPA) (5 mg/day) 0 to 204 months posttransplant. Drug monitoring was not initially used to adjust doses. The indications for switch were chronic CsA or Tac nephrotoxicity (12), acute CsA or Tac toxicity (3), severe facial dysmorphism (2), posttransplant lymphoproliferative disorder (PTLD) in remission (2), and hepatotoxicity in 1. Follow-up is 7 to 24 months. In the 12 patients switched because of chronic nephrotoxicity there was a significant decrease in serum creatinine [233+/-34 to 210+/-56 micromol/liter (P<0.05) at 6 months]. Facial dysmorphism improved in two patients. No relapse of PTLD was observed. Five patients developed pneumonia (two Pneumocystis carinii pneumonia, one infectious mononucleosis with polyclonal PTLD lung infiltrate) and two had bronchiolitis obliterans. There were no deaths. RAPA was discontinued in four patients, because of pneumonia in two, PTLD in one, and oral aphtous ulcers in one. RAPA levels were high (>15 ng/ml) in 7 of 13 (54%) patients. RAPA conversion provides adequate immunosuppression to enable CsA withdrawal. However, when converting patients to RAPA drug levels should be monitored to avoid over-immunosuppression and adequate antiviral and Pneumocystis carinii pneumonia prophylaxis should be given.

Effect of nitric oxide modulation on TGF-β1 and matrix proteins in chronic cyclosporine nephrotoxicity

Chronic cyclosporine (CsA) nephrotoxicity is characterized by interstitial fibrosis and afferent arteriolar hyalinosis. L-arginine (L-Arg), the substrate for nitric oxide (NO) synthase and N-nitro-L-arginine-methyl ester (L-NAME), the NO synthase inhibitor, were shown to modulate acute CsA nephrotoxicity. However, the mechanism of fibrosis in chronic CsA nephrotoxicity remains unclear. Thus, we examined the effect of NO modulation on fibrosis and the expression of transforming growth factor-beta1 (TGF-beta1) and matrix proteins in chronic CsA nephrotoxicity. Rats were administered CsA (7.5 mg/kg), CsA + L-Arg (1.7 g/kg), CsA + L-NAME (3.5 mg/kg), vehicle (VH), VH + L-Arg, and VH + L-NAME, and were sacrificed at 7 or 28 days. NO production, physiologic parameters, and histology were studied in addition to the mRNA expression of TGF-beta1, plasminogen activator inhibitor-1 (PAI-1) and the matrix proteins biglycan and collagens type I and IV by Northern and the protein expression of PAI-1 and fibronectin by enzyme-linked immunosorbent assay. While L-NAME strikingly reduced NO biosynthesis and worsened the glomerular filtration rate and CsA-induced fibrosis, L-Arg had the opposite beneficial effect. In addition, the CsA-induced up-regulated expression of TGF-beta1, PAI-1, and the matrix proteins biglycan, fibronectin, and collagen I was significantly increased with L-NAME and strikingly improved with L-Arg. Collagen IV expression was not affected. Also, NO modulation did not affect VH-treated rats. Chronic CsA nephrotoxicity can be aggravated by NO blockade and ameliorated by NO enhancement, suggesting that NO maintains a protective function. NO modulation was associated with a change in TGF-beta1 expression, which, in turn, was associated with alterations in matrix deposition and matrix degradation through its effect on PAI-1.

Beneficial effects of calcium channel blockade on acute glomerular hemodynamic changes induced by cyclosporine.

Experimental and human studies have documented that cyclosporine (CsA) acutely reduces glomerular filtration rate (GFR). It has been reported that this effect can be partially prevented by calcium (Ca) channel blockade; however, the mechanisms by which this combination exerts its beneficial effects are unknown. We evaluated glomerular ultrafiltration determinants during acute CsA administration in the rat. First, we determined that maximal whole-kidney functional changes occur between 120 and 150 minutes after CsA administration and confirmed that pretreatment of MWF rats with the Ca channel blocker lacidipine effectively prevents a reduction in GFR. Micropuncture measurements in CsA-treated animals showed that a reduction in GFR (0.49 +/- 0.24 v 0.88 +/- 0.26 mL/min; P < 0.05; CsA-treated v untreated rats) is associated with a significant increase in glomerular capillary pressure (Pgc; 63.1 +/- 2.1 v 52.8 +/- 2.8 mm Hg; P < 0.01) and efferent arteriolar resistance, whereas single-nephron (SN) GFR and ultrafiltration coefficient (Kf) are both importantly reduced (34.0 +/- 11.7 v 68.9 +/- 23.8 nL/min; P < 0.05 and 1.04 +/- 0.33 v 4.40 +/- 2.36 nL/min/mm Hg; P < 0.01, respectively). Lacidipine partially prevented SNGFR (43.1 +/- 14.3 nL/min) and Kf decline (2.08 +/- 1.10 nl/min/mm Hg) despite the presence of elevated Pgc. This study further documents that Ca channel blockade has favorable effects on CsA-induced acute renal dysfunction. The mechanism of protection includes the prevention of glomerular hemodynamic changes induced by CsA, mainly GFR decline and reduction in glomerular Kf.

TACROLIMUS USE IN KIDNEY-PANCREAS RECIPIENTS IS ASSOCIATED WITH LESS ACUTE RENAL DYSFUNCTION THAN CYCLOSPORINE

532 In many transplant programs tacrolimus (FK506) has replaced cyclosporine(CSA) for maintenance immunosuppression following kidney-pancreas transplantation. We reviewed all episodes of post-transplant acute renal dysfunction (ARD) in 89 combined kidney-pancreas transplant recipients from 1988-1996 to compare therapics. ARD was defined as a >20% increase in serum creatinine level from baseline. Demographics, transplant characteristics, diagnosis, management and outcome were assessed for each episode. There were 431 episodes ARD (4.8/patient); only 3% of patients had no ARD, 35% had 1-3 events, 44% had 4-7 events, and 18% had 8-12 events during an average follow-up of 1005 days. The median time post-transplant to ARD occurrence was 146 days (mean 521 days). There were no correlations with donor and recipient age, gender, and race when comparing patients with and without ARD. However, there were significantly more episodes of ARD in the 62 CSA patients compared to the 39 FK506 patients (4.7 vs. 3.2 events/patient, p<0.005); 12 patients received both therapies. There were no differences in either baseline serum creatinine (1.6 vs. 1.6 mg/dl), percent rise in serum creatinine (41% vs. 44%), and ARD creatinine (2.2 vs. 2.3 mg/dl) when comparing CSA and FK506 patients, respectively. There were 154 biopsies performed: the most common diagnoses were acute cellular rejection, CSA toxicity, and FK506 toxicity. 120 biopsies were in patients receiving CSA; the most common diagnoses were acute cellular rejection (49%) and CSA toxicity (23%). 34 biopsies were performed in FK506 patients with the most common diagnoses being FK506 toxicity (35%) and acute cellular rejection (29%). No differences in hospital admissions were observed when comparing CSA and FK506 patients (75% vs. 71%). In conclusion, FK506 use in kidney-pancreas transplant patients is associated with less ARD; the main cause of ARD in CSA-treated patients was acute cellular rejection while in FK506-treated patients ARD was most commonly related to nephrotoxicity.

Cyclosporine trough concentrations in predicting allograft rejection and renal toxicity up to 12 months after renal transplantation.

To evaluate the utility of cyclosporine (CsA) trough concentrations as a monitoring tool for acute graft rejections and CsA nephrotoxicity. Retrospective chart review. University-affiliated teaching hospital. One hundred thirty-seven adults who had undergone kidney transplantation. Clinical data extracted from the charts were CsA dosage, CsA trough levels (whole blood, HPLC method), biopsy findings to confirm acute rejections, and serum creatine to determine clearance by the Jelliffe method. Data were collected at up to 1 month, between 1 month and 3 months, and between 3 and 12 months after transplantation. For each time period, receiver's operating characteristics curves were generated to identify the optimum CsA concentration for avoiding acute rejection and CsA nephrotoxicity. At up to 1 month, the CsA therapeutic response threshold was 182 ng/ml (sensitivity 69%, specificity 84%, p<0.0001) and toxicity threshold for CsA nephrotoxicity was 204 ng/ml (sensitivity 89%, specificity 56%, p<0.0001). Between 1 month and 3 months, the respective figures were 175 ng/ml (sensitivity 58%, specificity 89%, p<0.0002) and 189 ng/ml (sensitivity 87%, specificity 65%, p<0.0001). Between 3 and 12 months, the CsA therapeutic response threshold decreased to 135 ng/ml (sensitivity 56%, specificity 40%, p>0.1) and the toxicity threshold for CsA nephrotoxicity remained relatively static at 204 ng/ml (sensitivity 100%, specificity 14%, p<0.0001). Early in CsA therapy it is essential to prevent graft rejection. Drug concentrations exceeding approximately 182 ng/ml threshold accomplish this goal. Later, successful therapy demands that CsA nephrotoxicity be avoided. This goal is accomplished by not exceeding a CsA concentration of 204 ng/ml.

Lazaroids prevent acute cyclosporine-induced renal vasoconstriction.

Cyclosporine (CsA)-induced nephrotoxicity may be due to intrarenal vasoconstriction and glomerular hypoperfusion. Several factors, including endothelin and prostanoids, are suggested mediators of this response. Recent evidence suggests that CsA leads to increased oxygen-derived free radical (ODFR) production and lipid peroxidation in renal tissue. Whether this leads to alterations in renal vessel reactivity is unclear. Lazaroids, such as U74389G, are radical-quenching antioxidants that inhibit ODFR-induced lipid peroxidation and may improve renal function after ischemia and reperfusion. We hypothesized that ODFRs contribute to CsA-induced alterations of the renal microcirculation. Rat hydronephrotic kidneys were studied by video microscopy. Interlobular arteriolar diameter and flow, afferent and efferent arteriolar diameters, and cardiac output were measured at 15-min intervals for 120 min. U74389G or its vehicle was infused 15 min before topical application of CsA to the kidney. The results were compared with U74389G alone and normal saline. CsA administration caused renal microvascular vasoconstriction (10-25% below baseline) and hypoperfusion (35% below baseline). Both vasoconstriction and hypoperfusion were significantly attenuated by U74389G (5-8% and 20% below baseline, respectively). Inhibition of lipid peroxidation by U74389G maintained renal blood flow during acute CsA administration. These data suggest that ODFRs are involved in the renal microvascular response to CsA. Inhibition of ODFR-induced lipid peroxidation may help prevent CsA-induced glomerular hypoperfusion. Lazaroids may prove an effective adjunct in reducing CsA-induced nephrotoxicity.

Frequency of hyperkalemia in recipients of simultaneous pancreas and kidney transplants with bladder drainage.

Hyperkalemia is the most frequent electrolyte abnormality found in whole organ transplant recipients receiving either cyclosporine (CsA) or tacrolimus (FK506). Recipients of a simultaneous pancreas kidney (SPK) transplant with bladder drainage may be particularly susceptible to hyperkalemia secondary to sodium loss from the bladder-drained pancreas, leading to decreased sodium delivery to potassium secretory sites of the kidney. We looked at the incidence of hyperkalemia in 34 type I diabetic SPK recipients transplanted at our center over the period from 1993 to 1995 and compared this with a cohort of 25 type I diabetic recipients of a kidney alone (K(Tx)) transplant. The incidence of hyperkalemia was 73.5% in recipients of an SPK, while it was 44% in K(Tx) recipients (P<0.05). CsA levels were higher, on average, in the SPK group (339 ng/ml+/-62 versus 272 ng/ml+/-58 in the K(Tx) group, P<0.05). However, CsA levels were not different between groups at the time of hyperkalemia, 320+/-74 versus 298+/-49 for SPK and K(Tx), respectively. CsA levels at the time of hyperkalemia were not different from those at the time of normokalemia. Other medications, serum bicarbonate, and renal function were not different in the groups. SPK recipients appear to have a greater incidence of hyperkalemia than kidney alone transplant recipients. This difference cannot be explained by higher acute CsA levels, other medications, or worse renal function. The increased incidence of hyperkalemia may, in part, be secondary to decreased sodium delivery to the transplanted kidney.

RENAL TRANSPLANTATION

Renal transplantation is the treatment of choice for end stage renal disease, and every patient with chronic renal failure should be considered for a transplant. The type of organ allograft (living related, living unrelated, or cadaver) and the degree of HLA matching influence short-term and long-term graft survival. At the current time, recipients of kidney transplants need to be maintained on chronic maintenance immunosuppression with potentially toxic medications to prevent rejection. Therefore, adequate long-term medical follow-up of kidney transplant recipients is essential. Initial posttransplant complications include graft dysfunction and infections. Acute rejection remains to be the most common cause of early graft dysfunction, although ischemic acute tubular necrosis (in cadaver kidneys) and CsA nephrotoxicity are other potential etiologies. Chronic rejection, CsA nephrotoxicity, and rarely de novo or recurrent renal disease are the usual causes of chronic graft dysfunction. Infections with immunomodulating viruses, especially with cytomegalovirus, hepatitis C, and EBV are relatively common in the transplant recipient. EBV has been associated with development of posttransplant lymphoproliferative disorder, a potentially serious disease that sometimes responds to tapering of immunosuppressive drugs. Other long-term post-transplant complications include hypertension, glucose intolerance, dyslipidemia, atherosclerosis, and liver disease. Future development of less toxic, yet effective, immunosuppressive drugs should limit the development of these potentially serious medical complications without compromising, and perhaps improving, graft survival.