Blood Cyclosporine Level Soon After Kidney Transplantation is a Major Determinant of Rejection: Insights From the Mycophenolate Steroid-Sparing Trial

Target organs express antigens directly recognized by antigen-specific T cells, thereby precipitating rejection. When early T-cell activation is inhibited, there is a low risk of rejection. We sought to determine the predictive values of serial posttransplant blood cyclosporine trough (C(0)) concentrations to minimize the risk for a first rejection episode compared with 2-hour postdose (C(2)) drug concentrations. The final aim of the study was to identify a concentration range for the best predictive pharmacokinetic parameter that should be targeted to reduce the risk of rejection. This possibility was explored in 334 de novo kidney transplant recipients who participated in the prospective, multicenter Mycophenolate Steroid-Sparing Trial. Among measurements performed during the first 6 months postsurgery, cyclosporine C(0) levels measured early after transplantation were the strongest predictor of acute graft rejection. Levels within 300 to 440 ng/mL were associated with the lowest risk of rejection, while patients with levels lower than 300 ng/mL showed a more than double risk. Cyclosporine trough values predicted allograft rejection with an accuracy of 74%, while C(2) levels had no predictive value. These findings underline the need to target cyclosporine therapy early posttransplant to modulate T-cell activation.

A Randomized Trial of Steroid Avoidance in Renal Transplant Patients Treated with Everolimus and Cyclosporine

In this randomized trial renal transplant recipients were treated with basiliximab, everolimus 3 mg/day, low-dose CsA. At transplantation, patients were randomized to stop steroids at the seventh day (group A) or to continue oral steroids in low doses (group B). Of the 113 patients enrolled, 65 were randomized to group A and 68 to group B. All patients were followed for 2 years. During the study 28 (43%) group A patients required reintroduced corticosteroids. One patient died, in group B. The Graft survival rate was 97% in group A and 90% in group B. There were more biopsy-proven rejections in group A (32% vs 16%; P = .044). The mean creatinine clearance was 54 +/- 21 mL/min in group A vs 56 +/- 22 mL/min in group B. Mean levels of serum cholesterol tended to be lower in group A, but the difference was of borderline significance (191 +/- 91 vs 251 +/- 188 mg/dL; P = .07). Vascular thrombosis (0 vs 5) and pneumonia requiring hospitalization (2 vs 7) tended to be more frequent in group B. Only three cases of CMV infection (1 vs 2) occurred. An immunosuppressive therapy with everolimus and low-dose CsA allows one to obtain excellent renal graft survival and stable graft function at 2 years. Early interruption of steroids in patients treated with this regimen may increase the risk of acute rejection, but neither affects graft survival nor graft function, while possibly reducing the risk of hyperlipemia and vascular thrombosis. About 60% of patients given everolimus and low-dose CsA can definitively stop steroids after 1 week.

Addition of Sirolimus to Cyclosporine in Long-Term Kidney Transplant Recipients to Withdraw Steroid

The aim of this study was to evaluate the feasibility of a steroid-free maintenance immunosuppression regimen in long-term renal transplant (KTx) recipients after addition of sirolimus (SRL) to cyclosporine (CsA)-based immunosuppression. A multicenter, prospective pilot study of steroid withdrawal (SW) was initiated for KTx patients. SW was divided into three phases: (A) conversion to a SRL + CsA + steroid regimen; (B) steroid tapering and withdrawal; and (C) maintenance with SRL + CsA. Primary endpoints of the study were incidence of acute biopsy-proven rejection (AR) and safety. In the A and B phases of the study 42 KTx patients (132 +/- 75 months post-Tx) were entered into the study, 18 of 42 (43%) with severe, acute side effects due to the CsA + SRL combination. These side effects were reversible with reduction of CsA or with suspension of the SRL/CsA combination. An amendment was introduced in the protocol to drastically reduce the CsA exposure to <50 ng/mL (trough) at the time of SRL addition. After this amendment, 39 other KTx patients entered the study and only 3 of 39 (8%) were discontinued because of toxic side effects. In the overall cohort of 81 KTx patients, the incidence of AR after SW was low (n = 5, 6.1%), all occurring within the first 3 months after SW. These findings indicate: (1) addition of SRL to very low-maintenance CyA exposure allows safe SW in KTx; (2) with the SRL + CsA combination, the incidence of AR after SW is low in long-term KTx patients; and (3) in the first 3 months after SW strict monitoring for early diagnosis and treatment of AR is mandatory.

[Renal transplantation in the North Italy Transplant program (NITp): Organ allocation and results]

Renal transplantation is an effective therapeutic tool for patients with end-stage renal diseases (ESRDs). Data reported in this article summarize the results obtained from 30 years' activity in the North Italy Transplant program (NITp), the first transplant organization in Italy that implemented a donor procurement and organ transplantation network. In the NITp kidney allocation is governed by a computerized algorithm, NITK3, put in place in 1997, aimed at ensuring equity, transparency and traceability during the stages of the allocation decision-making process. The NITp working group has recognized the NITK3 criteria and they are periodically reviewed following the results of the analysis of patients' transplantation odds. The results obtained with the use of the NITK3 algorithm have been very satisfactory: after 6 yrs, a significantly higher percentage of patients at immunological risk (sensitized or waiting for re-transplant), of patients waiting for >3 yrs and of patients with 0-1 HLA A,B,DR mismatches have been transplanted. Moreover, a higher percentage of kidneys were used locally (in a hospital within the procurement area), and this is known to stimulate donor procurement. Finally, we performed a preliminary statistical analysis of transplants carried out from 1998-2002 in 5/16 centers of the NITp area, demonstrating the quality of the NITp program in terms of patient and graft survival, and that donor and recipient age are the variables significantly impacting on transplant results.

Application of cyclosporine in renal transplantation: experience at the University of Padua

Cyclosporine (CsA) therapy has evolved considerably since its introduction as the primary immunosuppressant drug in the early 1980s and its use in renal transplantation continues to expand globally. In the last 20 years, there have been significant advances in formulation design, therapeutic drug monitoring guidelines, and the emerging role of CsA-based combination therapies that have resulted in a substantial improvement in clinical outcomes in renal transplant recipients. The aim of this work is to review developments in the application of CsA in kidney transplantation at our Center in Padua and to evaluate the clinical outcome of our patients in the last 15 years in relation to the new trends in CsA management strategies.

Biphasic behavior of the kinetics of 31P-containing metabolites in ischemic porcine kidneys

The assessment of kidney viability before transplantation (with a view of discarding nonviable organs) remains an obstacle to confidently extending organ harvesting to marginal donors. In the present study phosphorus magnetic resonance spectroscopy was used to monitor metabolic changes in (31)P-containing metabolites in isolated porcine kidneys. After various warm ischemia times, the organs were stored at 0 degrees C. Time-dependent changes in the phosphomonoester/inorganic-phosphate ratio were recorded at 0 degrees C were shown to follow a biexponential decay. The first-order kinetic rate constant of the short-time decay was strongly dependent on the warm ischemia time, a result that was discreted in terms of the underlying biochemistry. The metabolic events responsible for the dramatic decrease in phosphomonoester/inorganic phosphate ratio that occur immediately after organ perfusion and storage, suggest that any procedure to minimize organ damage must occur immediately after harvesting.

Persistently increased bone turnover and low bone density in long-term survivors to kidney transplantation

AIMS

There are few data on the long-term outcome of bone health in renal transplant recipients. We wanted to evaluate the prevalence of osteoporosis and related clinical fractures in long-term survivals to kidney transplantation.

METHODS

We carried out a cross-sectional study of 80 males and 44 females, aged 45 +/- 1 years, who had undergone kidney transplantation (KTx) 55.6 +/- 4.6 months earlier. Patients were treated according to standard immunosuppressive protocols.

RESULTS

High parathyroid hormone levels were observed in 55 out of the 124 patients (44.6%) and the prevalence of secondary hyperparathyroidism (SHPT) remained similar even when subjects were grouped according to the time elapsed since transplant. The Z scores for bone alkaline phosphatase, osteocalcin, urinary N telopeptide and galactosyl-hydroxylysine were increased as compared to normal controls, both in males and females (p < 0.05). Bone formation markers normalized, while bone resorption markers remained elevated in these patients even ten years after transplant. Vertebral and femoral osteoporosis were present in 37% and 56% of the patients, respectively, and no tendency toward a recovery in bone mass was seen even in those patients who had survived the longest time since KTx. Clinical fracture rate was 0.006 and 0.031 patient years, before and after KTx, respectively. The number of fractures was lower in patients taking lower mean daily doses of corticosteroids (p < 0.025). PTH levels positively correlated with bone alkaline phosphatase, osteocalcin and N telopeptide.

CONCLUSION

In conclusion, bone density is decreased and bone turnover increased even many years after KTx, with persistent SHPT and corticosteroid use being the main pathogenetic factors.

Alendronate prevents further bone loss in renal transplant recipients

The aim of this study was to investigate the effects of alendronate, calcitriol, and calcium in bone loss after kidney transplantation. We enrolled 40 patients (27 men and 13 women, aged 44.2 +/- 11.6 years) who had received renal allograft at least 6 months before (time since transplant, 61.2 +/- 44.6 months). At baseline, parathyroid hormone (PTH) was elevated in 53% of the patients and the Z scores for bone alkaline phosphatase (b-ALP) and urinary type I collagen cross-linked N-telopeptide (u-NTX) were higher than expected (p < 0.001). T scores for the lumbar spine (-2.4 +/- 1.0), total femur (-2.0 +/- 0.7), and femoral neck (-2.2 +/- 0.6) were reduced (p < 0.001). After the first observation, patients were advised to adhere to a diet containing 980 mg of calcium daily and their clinical, biochemical, and densitometric parameters were reassessed 1 year later. During this period, bone density decreased at the spine (-2.6 +/- 5.7%;p < 0.01), total femur (-1.4 +/- 4.2%; p < 0.05), and femoral neck (-2.0 +/- 3.0%; p < 0.001). Then, the patients were randomized into two groups: (1) group A-10 mg/day of alendronate, 0.50 microg/day of calcitriol, and 500 mg/day of calcium carbonate; and (2) group B-0.50 microg/day of calcitriol and 500 mg/day of calcium carbonate. A further metabolic and densitometric reevaluation was performed after the 12-month treatment period. At the randomization time, group A and group B patients did not differ as to the main demographic and clinical variables. After treatment, bone turnover markers showed a nonsignificant fall in group B patients, while both b-ALP and u-NTX decreased significantly in alendronate-treated patients. Bone density of the spine (+5.0 +/- 4.4%), femoral neck (+4.5 +/- 4.9%), and total femur (+3.9 +/- 2.8%) increased significantly only in the alendronate-treated patients. However, no trend toward further bone loss was noticed in calcitriol and calcium only treated subjects. No drug-related major adverse effect was recorded in the two groups. We conclude that renal transplanted patients continue to loose bone even in the long-term after the graft. Alendronate normalizes bone turnover and increases bone density. The association of calcitriol to this therapy seems to be advantageous for better controlling the complex abnormalities of skeletal metabolism encountered in these subjects.

Warm hepatic ischemia in pigs: effects of L-arginine and oligotide treatment

Reperfusion injury represents a key event leading to graft nonfunction. Maintaining adequate nitric oxide levels and stimulating vasodilator synthesis can probably minimize endothelial damage. The aim of this study was to investigate the effect of L-arginine, a substrate of nitric oxide synthesis, and oligotide, a promoter of prostacyclin synthesis, on liver function and morphology after warm ischemia-reperfusion injury. After constructing a side-to-side portacaval shunt, ischemia was induced by clamping the hepatic hilum for 2 h above the shunt, in 19 female pigs divided into a control group (n = 7), an L-arginine treatment group (n = 6), and an oligotide treatment group (n = 6). Liver function tests and measurements of serum and red blood cell malondialdehyde and plasma nitric oxide levels were performed before reperfusion and at 1, 10, 60, and 120 min after reperfusion. Liver biopsies, taken before reperfusion and at 30 min and 7 days after reperfusion, were analyzed for tissue malondialdehyde, histological-ultrastructural features, and apoptosis evaluation. Thirty minutes after reperfusion, liver malondialdehyde, sinusoidal congestion, necrosis, and apoptosis were significantly lower in the L-arginine group than in the controls (p < .05). On postoperative day 7, tissue malondialdehyde decreased, while plasma nitric oxide and hepatocyte glycogen content were increased in the L-arginine group compared to controls (p < .05). This study demonstrates the protective effect of L-arginine on hepatic lipoperoxidation and liver morphology in a pig model of warm ischemia-reperfusion injury. The increased plasma levels of nitric oxide a week after ischemia-reperfusion injury support the hypothesis that it has a role in preventing liver damage. The same beneficial effect was not confirmed for oligotide.

Deuterium nuclear magnetic resonance for evaluating the metabolic status of livers subjected to warm ischemia

BACKGROUND

The development of reliable methods for assessing the viability of currently available livers is expected to increase the number of successful transplantations.

METHODS

2 H nuclear magnetic resonance (NMR) was used to search for metabolic markers of ischemia in explanted rat livers. Deuterium oxide (2 H2O) was used as a source of 2 H. A total of 10-80% v/v 2 H2O was added to homogenates obtained from a liver biopsy and the formation of 2 H-labeled metabolites was monitored.

RESULTS

Some well-resolved 2 H resonances were found in the homogenates from biopsies of warm ischemic liver. Two of these were identified as [3-2 H] lactate and [2-2 H] lactate, and a linear relationship was found between the ratio of [[2-2 H] lactate] to [[3-2 H] lactate] and the warm ischemia time. The deuterium incorporation into lactate was explained on the basis of the metabolic events occurring under hypoxic conditions.

CONCLUSIONS

The experimental results support the application of 2 H NMR for a reliable evaluation of the metabolic status of a liver harvested from non-heart-beating donors.

Tacrolimus is highly effective in both dual and triple therapy regimens following renal transplantation. Spanish and Italian Tacrolimus Study Group

This open, multicenter, randomized, parallel-group study evaluated the efficacy and safety of tacrolimus-based dual and triple therapy regimens. For this 3-month study (with 12-month follow up), 491 adult renal transplant patients were randomized and received either dual therapy (tacrolimus/corticosteroids; 246 patients) or triple therapy (tacrolimus/corticosteroids/azathioprine; 245 patients). Patient survival rates at months 3 and 12 were 99.2 (dual) vs 99.6% (triple) and 97.8 vs 98.7%, respectively. Graft survival rates at months 3 and 12 were 94.1 (dual) vs 95.4% (triple) and 92.8 vs 93.3%, respectively. After 3 months, the incidences of treated acute rejection were 28.8 (dual) and 29.7% (triple); and 7.6 (dual) and 5.4% (triple) for corticosteroid-resistant acute rejections. Between months 4 and 12, three new first rejections were reported, (dual: 2, triple: 1). For leukopenia (1.3 vs 11.7%; P < 0.001) and anemia (14.8 vs 23.0%, P = 0.026), significantly higher incidences were reported in the triple therapy group. The incidence of de novo insulin-dependent diabetes was 5.6 (dual) and 4.0% (triple) at month 3. In terms of efficacy, no difference between the treatment groups was observed.

Cyclosporin-induced endothelial dysfunction and hypertension: are nitric oxide system abnormality and oxidative stress involved?

Hypertension is a major side effect of cyclosporin (CsA). While the mechanism(s) responsible are unclear, CsA-induced endothelial dysfunction and CsA-induced hypertension have been attributed to the CsA effect on the endothelial-derived factors controlling vasomotor tone. Endothelial nitric oxide (NO) is crucial in the maintenance of a state of basal vasodilation, and recent studies have suggested an NO-mediated counterregulatory mechanism protective from CsA-induced vasoconstriction. Our study evaluates endothelial nitric oxide synthase (ecNOS) gene status (PCR analysis) and plasma levels of NO metabolites (ELISA) in kidney and heart transplant patients under chronic CsA treatment with CsA-induced hypertension. Since CsA increases superoxide production, which metabolises NO, plasma hydroperoxides from cholesterol esters and from triglycerides and peroxynitrite were also evaluated (HPLC) as an index of the presence of superoxides and of "oxidative stress". Quantification of monocyte ecNOS mRNA and NO metabolites plasma levels from patients and controls (C) demonstrated NO system upregulation in patients notwithstanding the hypertension. The mean ecNOS to beta-actin ratio was 1.80 +/- 0.85 in patients vs 0.40 +/- 0.09 in C (P < 0.04). NO metabolites were 34.03 +/- 14.32 microM in patients vs 11.53 +/- 5.64 microM in C (P < 0.001). Hydroperoxides from cholesterol esters and from triglycerides were also increased in patients, 3.4 +/- 1.4 vs 1.3 +/- 0.6 integrated area units (i. a. u.), P < 0.007 and 10.6 +/- 6.4 vs 1.3 +/- 0.8 i. a. u., P < 0.008, respectively, as well as the peroxynitrite plasma level, 0.32 +/- 0.11 microM/l vs undetectable in C. This study confirms a CsA-induced NO system upregulation in transplanted patients. However, the NO-mediated counterregulatory system to CsA-induced vasoconstriction, present in normals, could be canceled in patients by CsA-induced superoxide (O2-) and free radical production which, by increasing NO metabolism, could contribute to CsA-induced vasoconstriction and hypertension and predispose to atherosclerosis.

Improved fibrinolytic capacity after withdrawal of steroid immunosuppression in renal transplant recipients

BACKGROUND

Long-term steroid immunosuppression has been associated with the prothrombotic state observed in renal transplant (RT) patients, in whom both hypercoagulability due to an increase of von Willebrand factor/factor VIII complex, and impaired fibrinolysis due to PAI-1 excess have been demonstrated. Our aim was to investigate the effect of steroid withdrawal on fibrinolytic capacity in a group of RT patients.

METHODS

The fibrinolytic study was performed in 28 RT patients under stable immunosuppression therapy with cyclosporine, azathioprine, and methylprednisolone; only 12 of these patients could repeat the study 6 months after steroid withdrawal. Euglobulin lysis time (ELT), tissue plasminogen activator activity (t-PA:act) and antigen (t-PA:Ag), PAI-1 activity (PAI-1:act), and antigen (PAI-1:Ag) were assayed on blood samples drawn before and 20 min after the venous occlusion test (VO).

RESULTS

An hypofibrinolytic state due to a significant increase in PAI-1 levels was confirmed in RT patients receiving triple immunosuppression therapy. RT patient who stayed off steroids showed a significant shortening of ELT both before (P=0.01) and 20' after VO (P=0.005) at the 6-month control. Moreover, after steroid withdrawal, PAI-1:Ag levels decreased significantly (P=0.002) and normalized; in a similar manner PAI-1:act levels also showed a significant decrease both before (P=0.001), and after VO (P=0.0001). The prevalence of RT patients with impaired fibrinolytic capacity was as high as 83.3% during steroid treatment, and dropped to 16.7% after steroid withdrawal.

CONCLUSIONS

Our findings confirm that steroid withdrawal may normalize impaired fibrinolytic capacity in RT patients; this improvement may further contribute to reduce the thrombotic risk associated with renal transplantation.

Mycophenolate mofetil (MMF) versus azathioprine (AZA) in pancreas transplantation: a single-center experience

AIM

Advances in immunosuppression and careful monitoring for rejection are largely responsible for improved results in pancreas transplantation. We conducted a retrospective study to establish the effectiveness of immunosuppressive therapy with mycophenolate mofetil (MMF) instead of azatioprine (AZA) in pancreas transplantation and to assess adverse effects in the two different immunosuppressive regimes.

SUBJECTS AND METHODS

Since 1991, 27 pancreas transplantations were performed in 25 patients at our Institute. For induction therapy, immunosuppressant protocol consisted of quadruple immunosuppressive therapy with cyclosporine, steroids, antilymphocyte globulin and AZA in 13 patients or MMF in 12 patients respectively.

RESULTS

Acute rejection occurred in 76% of patients in the AZA group compared with 53% in the MMF group. Steroid-resistant rejection was observed in 7% in the MMF group compared to 38% of patients on AZA (p < 0.01). Two kidney grafts were lost due to acute rejection in the AZA group, one pancreas was lost due to acute rejection and one to chronic rejection in the MMF group. There were no significant differences in CMV infection. Severe fungal infections were noted in 2 patients treated with MMF. Malignancy occurred in 1 patient (pancreas graft lymphoma) in MMF.

CONCLUSIONS

In conclusion, patients treated with MMF required less frequent and less intensive treatment for acute rejection. However, its short- and long-term side effects should be further investigated.

Liver-kidney-transplantation in type 1 primary hyperoxaluria: description and comments on a case

BACKGROUND

Primary hyperoxaluria leads to oxalosis, a systemic illness with fatal prognosis in uremic youngsters because of systemic complications.

CASE REPORT

A 14-year old boy with primary type 1 hyperoxaluria who had a long-lasting history of nephrolithiasis and passed from normal renal function to end-stage renal disease within 7 months. MEASUREMENT of alanine: glyoxylate aminotransferase (AGT) catalytic activity in the liver biopsy disclosed very low activity which was not. responsive to pyridoxin., thus the patient entered onto a priority national waiting list for liver-kidney transplantation and a week later received a combined transplant. In order to increase body clearance of oxalate, the patient underwent medical treatment to increase urine oxalate solubility (sodium and potassium citrate oral therapy, magnesium supplementation and increase of diuresis) and intensive dialysis both before and after transplantation.

COMMENT

The medical approach to the treatment of this rare illness is discussed. Since the major risk for the grafted kidney is related to the oxalate burden, i.e. oxalate deposition from the body deposits to the kidney that becomes irreversibly damaged, treatment consists of increasing the body clearance of oxalate both by increasing oxalate solubility in the urine and with intensive dialysis performed both before and after combined transplantation. To the same extent (by limiting body oxalate deposits), a relatively early (native GFR 20-25 ml/minute) transplantation is advisable.

Parathyroid hormone and bone metabolism in kidney-transplanted patients

BACKGROUND

Decreases in bone mass and increased susceptibility to fractures are well-recognized complications in organ transplants.

SUBJECTS AND METHODS

We performed a cross-sectional study on 60 patients (40 males, 20 females, mean age 43.2 +/- 1.06, SE range 22 - 70) who underwent kidney transplantation (KTX) 55.6 +/- 4.5 months before. Blood and 24-hour urine samples were analyzed for the main parameters of mineral metabolism, and also for osteocalcin (BGP), bone alkaline phosphatase (b-ALP, urine N-telopeptid (u-NTx) and urine galactosyl-hydroxylysine (u-Ghyl). DEXA scan of the lumbar spine (LS) and proximal femur (PF) and ultrasound determination of the heel (stiffness) was also performed.

RESULTS

T-score values for bone density (BD) were 2.14 +/- 0.11 SD's for LS, -2.56 +/- 0.09 for PF and 2.49 +/- 0.15 for stiffness. There were 29 peripheral fractures in 16 patients. The rate of fractures before KTX were 0.0011 per patient/year and 0.0005 after transplantation (p < 0.02). When expressed as number of SD's with respect to normal controls, BGP (1.48 +/- 0.23), b-ALP (0.95 +/- 0.19), u-NTx excretion correlated negatively with BD at the femoral neck (p < 0.02) and trochanter (p < 0.03). Cumulative steroids intake were negatively correlated with b-ALP positively (p < 0.05). Current CsA was positively correlated with b-ALP (p < 0.001). Both cumulative steroid (p < 0.02) and CSA (p < 0.01) intakes were negatively correlated with BD at Wards triangle.

CONCLUSIONS

Our data demonstrate an important bone depletion at each stage KTX. PTH plays a major role in the observed increase in bone turnover, exacerbating the negative effects on the bone on immunosuppressive treatment. Glucocorticosteroid therapy is an important risk factor for osteoporosis in this setting also.

Oxidative stress and nitric oxide system in post-transplant hypertension

BACKGROUND

CsA-induced endothelial dysfunction and CsA-induced hypertension have been attributed to CsA effects on the endothelial-derived factors controlling vasomotor tone, but the mechanisms responsible are unclear. Endothelial nitric oxide (NO) is known to maintain a state of basal vasodilation and recently a NO mediated counterregulatory mechanism protective from CsA-induced vasoconstriction has been suggested.

PATIENTS AND METHODS

Our study evaluates ecNOS gene status and NO metabolites in kidney transplanted patients under chronic CsA treatment with CsA-induced hypertension. Since CsA increases superoxide production, which metabolizes NO, plasma hydroperoxides and peroxynitrite were also evaluated as index of the presence of "oxidative stress".

RESULTS

Quantification of monocyte ecNOS mRNA and NO metabolites plasma level from patients and control subjects (C) demonstrated NO system up regulation in patients notwithstanding hypertension. The mean ecNOS to beta-actin ratio was 2.00 +/- 0.87 vs 0.29 +/- 0.08 in C, p < 0.04. NO metabolite plasma level was 30.03 +/- 9.62 mM vs 9.37 +/- 3.86, p < 0.001. Hydroperoxides were also increased in patients: 3.6 +/- 1.6 i.a.u. vs 1.4 +/- 0.8, p < 0.007 (from cholesterol esters) and 10.8 +/- 6.6 vs 1.5 +/- 0.9, p < 0.008 (from triglycerides) as well as peroxynitrite plasma level: 0.36+/- 0.14 mM/L vs undetectable in C.

CONCLUSIONS

This study confirms a NO system up-regulation in transplanted patients. However, the counterregolatory system to CsA-induced vasoconstriction, could be cancelled by CsA induced superoxide and free radicals production which, increasing NO metabolism could contribute to CsA induced vasoconstriction and hypertension.