Evolution of Proteinuria After Conversion From Calcineurin Inhibitors (CNI) to Sirolimus (SRL) in Renal Transplant Patients: A Multicenter Study

Conversion from calcineurin inhibitors (CNI) to sirolimus (SRL) has become an option in patients with chronic allograft nephropathy or other conditions. However, in some cases an increase of proteinuria has been reported after such therapeutic intervention. The aim of this study was to characterize the clinical course of this so far unexplained proteinuria after conversion. We performed a retrospective analysis evaluating 94 renal transplant patients from various Spanish centers. Proteinuria (629 determinations) and clinical developments were analyzed between 6 months before and 6 months after conversion. Patients were divided into three groups according to mean proteinuria before conversion (group A: <300 mg/d; group B: 300 to 2000 mg/d; and group C: >2 g/d). The mean proteinuria level was 1.69 g/24 h (n = 312 determinations) before and 2.36 g/24 h after conversion (n = 317 determinations; P = .006), which corresponds to an overall increase of 25% (1.55 to 1.69 g/24 h considering only determinations of 1 month before and 1 month after conversion; P = NS). We could not detect any clear correlation between proteinuria and serum creatinine nor between changes of proteinuria and changes of serum creatinine. A variance analysis for repeated measures showed an increase in proteinuria compared to the preconversion values (P = .003), and when the three groups of preconversion proteinuria were evaluated separately it could be observed that this change in the evolution of proteinuria was almost completely dependent of an increase in the group C (preconversion proteinuria greater than 2 g/d; P = .03), whereas in the other two groups changes were almost irrelevant. Finally, the switch to SRL in renal transplant recipients is followed by an increase in the level of proteinuria predominantly dependent of an increase in patients with high levels of preconversion proteinuria, whereas it seems to be irrelevant in patients without or with light or moderate proteinuria. These results suggest that this might not be a direct effect of SRL.

Sirolimus-Based Therapy With or Without Cyclosporine: Long-Term Follow-up in Renal Transplant Patients

This open-label, phase 3b, extension trial in renal transplant recipients (Sirolimus Study 311) assessed the long-term safety of sirolimus (SRL) administered with cyclosporine (CsA) (SRL + CsA group, n = 98) or without CsA (SRL group, n = 69). Renal transplant recipients who had either completed one of seven previous SRL studies sponsored by Wyeth Research or had participated for > or =3 months and reached a protocol-designated endpoint were eligible for enrollment. Data were available for 167 patients, all of whom initially received steroids. Mean total SRL exposure was 1526 days, including previous study participation. After enrollment in the extension study, there were significantly more acute rejections in the SRL + CsA group (6.1% vs 0%, P < .05). Differences in rates of graft loss (3.1% vs 1.4%) and death (6.1% vs 1.4%) were not significantly different between SRL + CsA and SRL groups, respectively. At 48 months after transplantation, calculated GFR (53.4 vs 70.9 mL/min) and hemoglobin (124.9 vs 136.6 g/L) were significantly better in the SRL group. Lipid values were not significantly different between groups at 48 months. The incidence of treatment-emergent increased creatinine, anemia, hypertension, headache, epistaxis, abnormal kidney function, and upper respiratory infection were significantly higher in the SRL + CsA group, whereas no adverse events were significantly higher in the SRL group. Malignancies were reported more frequently (11.2% vs 0%) with SRL + CsA. Results from this extension study indicate that SRL-based therapy without CsA is a safe alternative to combination therapy with CsA, offering long-term improvement in renal function with no increased risk of late acute rejection.

[Pharmacogenetics of angiotensin system in non diabetic nephropathy]

BACKGROUND

Genetic variability could contribute to the response to pharmacological treatment in patients with nephropathy. In albuminuric diabetic patients the renoprotective effect of angiotensin I-converting enzyme (ACE) inhibition should be lower among homozygotes for the deletion allele (DD) compared to II-homozygotes.

METHODS

A total of 71 non-diabetic chronic nephropathy patients were treated with losartan (n = 37) or amlodipine (n = 34). Blood pressure and proteinuria were determined before and after the treatment, and changes in the mean values were statistically compared. Patients were genotyped for the ACE-I/D, angiotensin I receptor type 1 (AGTR1)-1166 A/C, and angiotensinogen (AGT)-M235T polymorphims, and the reduction of blood pressure and proteinuria between the different genotypes were compared.

RESULTS

The reduction in systolic or diastolic blood pressure was not found to be different between the ACE-I/D or AGT-M/T genotypes in patients treated with losartan or amlodipine. In patients treated with losartan, we found a significantly higher reduction of diastolic blood pressure in AGTR1-AA patients compared to AC patients (p = 0,0024). We did not find differences in proteinuria-reduction between the different genotypes in patients treated with losartan or amlodipine.

CONCLUSIONS

Our data show that the effects of losartan and amlodipine on the absolute mean reduction of blood pressure and proteinuria in non-diabetic nephropathy patients are similar between the different ACE or AGT genotypes. Although based on a small number of patients, the AGTR1-AA genotype was associated with a significantly higher reduction in diastolic blood pressure among losartan-treated patients. Additional studies are necessary to refute or confirm this association.

Lessons from cyclosporine monotherapy in renal transplantation: the impact of acute rejection on long-term allograft outcome

The introduction of cyclosporine in kidney transplantation rapidly improved short and medium term graft and patient survival rates. Initially many trials used cyclosporine monotherapy to avoid steroid toxicity, but high acute rejection rates lead to a change in the immunosuppressant scheme. The use of prophylactic steroids significantly decreased acute rejection rates, but the long-term benefit of such a reduction has not been assessed.

METHODS

Retrospective analysis of the impact of early acute rejection on long-term outcome (10 years) in 264 consecutive renal transplants performed in a single institution between 1986 and 1993 using cyclosporine monotherapy (CM) (n=139) versus cyclosporine and prednisone (CS) (n=125). Different protocols were used for elderly or immunological high-risk patients and for transplants with delayed graft function and therefore these patients are not included. The incidence and severity of acute rejection episodes and long-term patient and graft survivals were analyzed.

RESULTS

At 1 year, acute rejection episodes showed significantly higher frequency in the CM group than in the CS group (72.66% vs 46.40%). Nevertheless, graft and patient survival rates were similar at 1, 5, and 10 years (Graft: 96.38%, 78.77%, and 59.84% vs 92.59%, 75.62%, and 53.44%;

PATIENT

99.27%, 95.06%, and 84.76% and 95.9%, 93.09%, and 88.28%).

CONCLUSION

The addition of prophylactic steroids decreases the incidence of acute rejection but does not improve the long-term graft survival. These findings suggest that in an era of new immunosuppressants, fewer acute rejection episodes will be evident requiring more effort to detect and treat subclinical rejections.

Cigarette smoke concentrate increases 8-epi-PGF2alpha and TGFbeta1 secretion in rat mesangial cells

Epidemiological studies have shown that cigarette smoke, an oxidant agent, is a risk factor for the development of diabetic nephropathy (DN), in which pathogenesis transforming growth factor beta(1) (TGFbeta(1)) plays a key role. In our experimental model we exposed mesangial cell cultures to cigarette smoke concentrate (CSC) to study the effect of smoking on the pathogenesis of DN. Thus, we analyzed the effect of CSC on TGFbeta(1) and lipid peroxidation (8-epi-PGF(2alpha)) in rat mesangial cells. Furthermore, since the protein kinase C (PKC) pathway appears to be a key factor for the enhanced production of TGFbeta(1), we also analyzed the effect of the selective PKCbeta inhibitor LY379196 on TGFbeta(1) response to CSC. CSC induced an increase of both TGFbeta(1) and 8-epi-PGF(2) compared to basal conditions (5 mM glucose). The CSC-induced increase in TGFbeta(1) secretion was significantly suppressed by LY379196. These data suggest that smoking could increase TGFbeta(1) production, probably due to oxidative stress and PKCbeta activation. This finding supports the concept that smoking is a risk factor for DN development.

New concepts in cyclosporine pharmacokinetic and dynamic monitoring: the impact of concomitant immunosuppression on target C2 concentrations

BACKGROUND

There is a correlation between cyclosporine (CsA) pharmacokinetics (PK) and pharmacodynamics (PD), especially 2 hours after drug administration.

AIM

To evaluate the relationship between CsA PK and PD profiles in two groups of stable renal transplant patients treated with CsA alone or CsA plus mycophenolate mofetil (CsA+MMF), so as to define the best target for C2 and clarify the impact of concomitant immunosuppression.

METHODS

Thirty-eight stable renal transplant recipients were treated with CsA (n=20) or CsA+MMF (n=18). Twelve nontreated normal healthy controls (NHC) were also included. Calcineurin activity (CNa), IL-2 production, and CsA levels were measured at 0 and 2 hours postdose.

RESULTS

There were no significant differences in median CsA C2 values and CNa between the CsA alone and the CsA+MMF groups (388 microg/L and 497.5 microg/L and CNa 2h; 3.92% alkaline phosphatase [AP]; 3.94% AP, respectively). In vitro production of IL-2 was significantly lower in the CsA+MMF group than in the CsA group (median IL-2 2h: 280.52 ng/L, 169.48 ng/L, P<.001). The correlations (r) between C2 and CNa 2h were: CsA r=0.74; CsA+MMF r=0.84 (P<.001 in both cases).

CONCLUSIONS

In stable renal transplant patients, median CsA C2 values below 500 microg/L were associated with inhibition of CNa and IL-2 synthesis. CNa and IL-2 production may be good biological markers of CsA immunosuppression. The measurement of CNa depends mainly on CsA concentration, whereas in vitro IL-2 production reflects the effect of both CsA and MMF. Further studies are necessary to define the optimal C2 target concentration and the possible impact of concomitant immunosuppression.

The effects of smoking and its cessation on 8-epi-PGF2alpha and transforming growth factor-beta 1 in Type 1 diabetes mellitus

BACKGROUND

Oxidative stress and transforming growth factor-beta 1 (TGF-beta1) are associated with diabetic complications, and smoking is a risk factor.

AIMS

This study aimed (i) to compare urinary 8-epi-PGF2alpha and plasma and urinary TGF-beta1 levels obtained in heavy smokers with Type 1 diabetes with those observed in age-matched non-smoker patients with Type 1 diabetes and controls, and (ii) to investigate the effects of smoking cessation (SC) on the above-mentioned parameters in patients with Type 1 diabetes.

METHODS AND RESULTS

Compared with control subjects (n = 12), non-smoker diabetic patients (n = 12) presented higher values of urinary 8-epi-PGF2alpha (74.2 +/- 29.6 vs. 29.6 +/- 11.1 pg/mg urinary creatinine, P = 0.01), plasma TGF-beta1 (7.7 +/- 4.7 vs. 3.6 +/- 1.7 ng/ml, P = 0.001) and urinary TGF-beta1 (15.3 +/- 6.3 vs. 8.1 +/- 4.4 ng/mg urinary creatinine, P = 0.02). Compared with non-smoker diabetic patients, smoker diabetic patients (n = 16) showed higher levels of urinary 8-epi-PGF2alpha (107.8 +/- 40.2 vs. 74.2 +/- 29.6 pg/mg urinary creatinine, P = 0.0001), plasma TGF-beta1 (12.6 +/- 4.9 vs. 7.7 +/- 4.7 ng/ml, P = 0.001) and urinary TGF-beta1 (27.5 +/- 16.0 vs. 15.3 +/- 6.3 ng/mg urinary creatinine, P = 0.01). Smoker patients were included in a smoking cessation programme. In the 10 patients that gave up smoking there was a reduction of urinary 8-epi-PGF2alpha (basal: 110.47 +/- 47.0 vs. week 12: 73.2 +/- 25.6; P < 0.001), plasma TGF-beta1 (basal: 11.2 +/- 5.9 vs. week 12: 4.89 +/- 2.25; P < 0.01) and urinary TGF-beta1 (basal: 18.12 +/- 9.27 vs. week 12: 10.32 +/- 2.0; P < 0.01) levels.

CONCLUSIONS

In patients with Type 1 diabetes, smoking increased oxidative stress, evaluated by lipid peroxidation, and TGF-beta1 production. Smoking cessation decreased these parameters, providing additional support to encourage diabetic patients to give up smoking.

[Guidelines on hemodialysis-associated viral infections]

The viric infections influence morbi-mortality in Chronic kidney Disease patients in hemodialysis therapy and can affect to the Staff of the Units. The guides considered the most relevant virus at the present moment: C Virus, B Virus and HIV. To prevent horizontal nosocomial transmission is necessary the observance always the universal precautions in the HD units, although sometimes can appeared seroconversions and epidemic bud when exist a break of these. Is analyzed different situations with special focus in units for acute patients. The following steps under the suspicious of the epidemic bud appeared in one of the annexes together with legislation according to this case. Respect to the staff in every one of the virus is shown prevention patterns, serologic markers to perform when an accident with infected blood occur, also is considered when treatment is indicated. The guides considered too the conditions necessary for include these patients on waiting list for kidney transplantation.

Reflex sympathetic dystrophy syndrome in renal transplanted patients under immunosuppression with tacrolimus

Reflex sympathetic dystrophy syndrome (RSDS), which probably has a multifactorial etiology, may appear after kidney transplantation. Its clinical manifestations include severe periarticular pain with inflammatory signs, especially in knees and ankles, causing functional disability. Symptoms develop during the first 3 months after transplantation and usually disappear 3 to 6 months later without sequelae. In renal transplant recipients it has previously been related to immunosuppressive treatment with cyclosporine. Therefore we had suggested that introducing tacrolimus could be a therapeutic option. We now present four cases of RSDS in kidney transplant recipients treated with tacrolimus. All but one patient were receiving tacrolimus monotherapy, excluding other drugs that might have been involved to cause the syndrome. It is also interesting that one of our cases develop RSDS long after transplantation when immunosuppressive treatment was changed. Symptoms correlated with an increase in alkaline phosphatase and with bone scintigraphy findings. All patients recovered without sequels 3 to 6 months afterward. In conclusion, RSDS is a relevant osteoarticular complication in patients receiving either anticalcineurinic drug (CyA or tacrolimus), even under monotherapy or with a low steroid dose.

Early elimination of cyclosporine in kidney transplant recipients receiving sirolimus prevents progression of chronic pathologic allograft lesions

Cyclosporine elimination in a regimen including sirolimus has been shown to be a safe and effective approach to improve graft function. Nevertheless, it is still unknown whether the functional benefit of CyA withdrawal coincides with a subsequent reduction in histologic lesions of chronic damage or development of chronic allograft nephropathy. This consideration would forecast a reduction in the rate of long-term graft loss. We analyzed 114 graft biopsies from a subgroup of 57 patients that had been included in a randomized study to eliminate CyA at 3 months posttransplant from a regimen including sirolimus either in group A CyA + SRL vs group B of SRL with CyA elimination at 3 months. Every patient had two biopsies, one at transplantation and another at 1 year. The biopsy reading was performed in a blinded manner by a central pathologist using the Banff 1997 and the CADI classifications. A significantly lower rate of progression of tubular and interstitial chronic lesions between basal and 1-year biopsies was observed for group B patients. In addition, the incidence of new cases of chronic allograft nephropathy during the first year was significantly lower in the group in which CyA had been eliminated at 3 months posttransplant. We conclude that early elimination of CyA in the first months posttransplant, when SRL is used as the main immunosuppressant, reduces the appearance or worsening of chronic histologic lesions, probably as a consequence of long-term CyA toxicity prevention.

Effect of apolipoprotein polymorphisms in renal transplant recipients

Cardiovascular disease (CVD) is the main cause of mortality among long-term renal transplant recipients (RTR). On the other hand, allograft chronic nephropathy is the primary cause of graft loss among long-term RTR. Hyperlipidemia is a predisposing factor for both conditions. Polymorphisms of the apolipoproteins modulate lipid metabolism. The aim of the study was to evaluate the effect of apo A-I, apo A-IV and apo C-III genotypes on the long-term results of renal transplantation. Clinical assessment (renal allograft and patient survival) and genotyping for apo A-I (+83C/T), apo C-III (Sst I), and apo A-IV (Thr347Ser and Gln360His) polymorphisms were evaluated in 516 kidney transplant patients and correlated with the clinical evolution over 12 months. The distribution of the apo A-I (+83C/T) polymorphisms was: CC 91.9%, CT 7.9%, and TT 0.2%. The apo C-III genotype showed: S1S1 84.4%, S1S2 15.2%, and S2S2 0.4%. The apo A-IV (Pvu II) polymorphism was: GG 82%, GT 18%, and 0% TT. Finally, the frequency of apo A-IV (Hinf I) polymorphism was: AA 69%, AT 27%, and TT 4%. The frequency of polymorphisms was similar between men and women. In conclusion, there was no significant influence of apolipoprotein polymorphisms on renal and patient survival.

[Role of transforming growth factor beta-1 gene polymorphisms in the development of chronic allograft nephropathy in renal transplant recipients]

BACKGROUND

Chronic allograft nephropathy (CAN) is the main cause of graft loss after the first year of transplantation, and renal biopsies show a predominance of fibrotic lesions. Human transforming growth factor beta-1 (TGF-beta 1) is the principal profibrogenetic cytokine which has been recently implicated in the development of CAN. Seven TGF-beta 1 gene polymorphisms have been recently described and some of them have been related to the development of several diseases.

AIM

To analyse the relationship between TGF-beta 1 gene polymorphisms and the development of CAN in a group of renal transplant patients with a long-term follow-up.

METHODS

A restriction enzyme-based method for TGF-beta 1 genotyping was used to detect four TGF-beta 1 gene polymorphisms in codon 10, 25 and 5'-flanking region (-800 and -509 positions). A retrospective case-control study were performed on sixty renal transplant recipients with 8 years of post-transplant, 22 of them with CAN (cases) and 38 with normal graft function (controls). We studied 73 subjects to analyse the distribution of the genotypes in the area.

RESULTS

The genotype frequencies were similar in the study and control group. The presence of chronic allograft nephropathy was statistically associated with the combination Pro/Pro10 TT509 polymorphism in the TGF-beta 1 gene, and these patients develop chronic rejection more quickly than the rest of the patients. Chronic allograft nephropathy was also associated with delta age recipient-donor, with older donors being a significant risk factor for chronic nephropathy. The logistic regression analysis confirmed the independent role of TT509 Pro/Pro10 TGF-beta 1 polymorphism with a Odd Ratio of 5.8 (1.14-29.7) in chronic nephropathy being the delta age recipient-donor a confounder factor but not an effect modifier. The rest of the TGF-beta 1 gene polymorphisms and the classic risk factors were not associated with the development of chronic allograft nephropathy.

CONCLUSIONS

These data suggest a leading role for TGF-beta 1 gene polymorphisms (TT509 Pro/Pro10) in the development of chronic allograft nephropathy. The identification of this genetic predisposition to chronic allograft rejection could play a decisive role in the prevention of this common pathology.

Pharmacokinetic and pharmacodynamic correlations of cyclosporine therapy in stable renal transplant patients: evaluation of long-term target C(2)

We investigated the relationship between the pharmacokinetics and pharmacodynamics of cyclosporine in 15 stable renal transplant patients in order to define an effective and safe therapeutic range. The area under the curve of the first 4 h (AUC(0-4)), trough (C(0)) and 2 h (C(2)) levels showed median values of 1655 ng x h/ml, 114 ng/ml and 384 ng/ml, respectively. C(2) showed a strong correlation with AUC(0-4) (r=0.942, p=0.0005). C(0) correlated poorly with C(2) and AUC(0-4) (r=0.596, p=0.019 and r=0.538, p=0.031, respectively). Calcineurine activity (CNa) was 6.74% at 0 h and 3.90% at 2 h, representing significant reductions (82% and 89.6%, respectively; p<0.0005) compared with normal healthy controls (median basal value 37.4%). IL-2 production was 349 pg/ml at 0 h and 276.35 pg/ml at 2 h; both results were significantly lower (reductions of 44.5% and 56.1%, respectively; p=0.04 and 0.005) than the controls of 629.1 pg/ml. IFN-gamma at 2 h post-dose (8.16 UI/ml) was significantly lower (72.1% reduction, p=0.005) than in controls (29.2 UI/ml). There was a good correlation between CNa and IFN-gamma production, particularly at 2 h post-dose (r=0.537, p=0.007), and a fair correlation between CNa and IL-2 concentration (p=0.030, r=0.426). C(2) showed an inverse significant correlation with CNa (Spearman's p=0.000, r=-0.753), IL-2 (p=0.000, r=-0.725) and IFN-gamma (p=0.000, r=-0.701) production. In treated patients, the Emax inhibitory sigmoidal model showed that a C(2) of 279 ng/ml was needed to achieve a 50% inhibition (EC50) of IL-2 and INF-gamma production. The results demonstrated a significant inhibition of calcineurin activity and IL-2 and IFN-gamma production in patients receiving cyclosporine monotherapy compared to healthy controls. A median C(2) value of 384 ng/ml was associated with a good degree of inhibition of CNa and IL-2 and IFN-gamma synthesis, and the lack of rejection episodes and relevant toxicity.

Pattern of renal dysfunction associated with myocardial revascularization surgery and cardiopulmonary bypass

BACKGROUND AND OBJECTIVE

A variable incidence rate of renal dysfunction (3-35%) after cardiac surgery with cardiopulmonary bypass has been reported. The aim was to define the typical pattern of renal dysfunction that follows coronary surgery with cardiopulmonary bypass using albumin, immunoglobulin (IgG), alpha1-microglobulin and beta-glucosaminidase (beta-NAG) excretion as indicators.

METHODS

Twenty patients with preoperative normal renal function, defined by plasma creatinine, creatinine clearance, fractional excretion of sodium and renal excretion of proteins, undergoing elective myocardial revascularization surgery with cardiopulmonary bypass, were prospectively studied. Variables recorded were demographic and haemodynamic variables, duration of cardiopulmonary bypass and aortic clamping, intra- and postoperative urine output, plasma creatinine concentration, creatinine clearance and excretion of sodium, albumin, IgG, beta-glucosaminidase (beta-NAG), and alpha1-microglobulin. Measurements were made preoperatively, immediately before and then during and immediately after cardiopulmonary bypass, and again at 1, 24, 72 h, 7 and 40 days following surgery.

RESULTS

Albumin and IgG excretion rose significantly during cardiopulmonary bypass (P < 0.05), remaining at these levels at 24 h postoperatively. An increase of alpha1-microglobulin and beta-NAG concentrations was observed during cardiopulmonary bypass (P < 0.05), which were maintained until the seventh postoperative day and remained elevated in some patients at the 40th postoperative day. This correlated with preoperative diabetes mellitus (P < 0.001), low cardiac output after cardiopulmonary bypass (P < 0.001) and the duration of stay in the intensive care unit (P < 0.001).

CONCLUSIONS

The pattern of renal dysfunction after cardiopulmonary bypass for myocardial revascularization is characterized by temporary renal dysfunction at both glomerular and tubular levels with an onset within 24 h of surgery and which lasts between 24 h and 40 days, respectively, following surgery.

Cardiovascular risk factors of sirolimus compared with cyclosporine: early experience from two randomized trials in renal transplantation

INTRODUCTION

Renal transplant recipients are at a higher risk of cardiovascular events, including death. This paper examines cardiovascular risk factors in two phase II studies comparing cyclosporine (CsA) with sirolimus-based therapy.

METHODS

In two phase II studies, patients (n = 161) were randomized at the time of transplantation to receive either sirolimus or CsA in triple-therapy regimens with either azathioprine (Study A) or mycophenolate mofetil (Study B), and corticosteroids. Sirolimus whole blood trough levels were targeted to 30 ng/mL for 2 months and 15 ng/mL thereafter. Pooled results of the two studies are reported.

RESULTS

When patients receiving sirolimus were compared with those receiving CsA, peak cholesterol and trigylcerides at 2 months were markedly and significant higher with sirolimus therapy. The difference between groups decreased thereafter and was not significant from 12 through 24 months. Control of lipid parameters in sirolimus-treated patients was achieved by decreasing the target trough levels after 2 months and by using lipid-lowering agents. Sirolimus-based therapy was associated with a lower incidence of treatment-emergent hypertension (47.5% vs 29.6%, P <.024). At 24 months, the calculated glomerular filtration rate was significantly better with sirolimus (51.3 vs 65.1 mL/min, P <.001). There were no significant differences in the incidences of diabetes or death due to cardiovascular events.

CONCLUSION

Patients receiving sirolimus experience an initial increase in lipid levels, but these effects are manageable with the use of lipid-lowering agents. Hypertension was less frequent and renal function was improved with CsA-free, sirolimus-based therapy. Based on this early experience, overall cardiovascular risk does not appear to be increased with sirolimus-based compared with CsA-based therapy.

Bicêtre hospital experience with sirolimus-based therapy in human renal transplantation: the Sirolimus European Renal Transplant Study

In 11 European centers, first cadaveric renal allograft recipients were randomized to CsA (n = 42) or sirolimus (n = 41). Dosing of these agents was concentration-controlled and open-labeled. All patients received corticosteroids and azathioprine. At 12 months, graft survival (98% sirolimus vs 93% CsA), patient survival (100% vs 98%), and incidence of biopsy-confirmed acute rejection (41% vs 38%) were similar. Serum creatinine was lower with sirolimus, significantly (P </=.05) so at 3 and 4 months, and serum uric acid and magnesium were normal. Laboratory abnormalities were reported significantly more often with sirolimus, which included hypertriglyceridemia (51% vs 12%), hypercholesterolemia (44% vs 14%), thrombocytopenia (37% vs 0%), leukopenia (39% vs 14%), and, of lesser importance, increased liver enzymes and hypokalemia. These abnormalities improved 2 months after transplantation when the sirolimus target trough level was lowered from 30 to 15 ng/mL. Occurrence of cytomegalovirus was comparable (14% vs 12%), but incidence of herpes simplex (24% vs 10%, P =.08) and pneumonia (17% vs 2%, P =.03) were higher with sirolimus. No gingival hyperplasia was seen with sirolimus, tremor was rare, and hypertension was less frequent (17% vs 33%). Two malignancies were observed with CsA, none with sirolimus. Results at 12 months suggest that sirolimus can be used as base therapy in the prophylaxis of acute renal transplant rejection, and has a safety profile that differs from that of CsA.

[Interaction between sildenafil and calcineurin inhibitors in renal transplant recipients with erectile dysfunction]

AIM

Hepatic metabolism of sildenafil uses the same metabolic pathway as the calcineurin inhibitors (cyclosporine/tacrolimus), through the CYP3A4 isoenzyme. The aim of this pilot study was to evaluate the potential interaction between sildenafil therapy and circulating levels of cyclosporine and tacrolimus in a group of steady-state renal transplant recipients with erectile dysfunction.

MATERIAL AND METHODS

A prospective pilot study of sildenafil interactions was carried out in 9 stable male renal transplant recipients with severe erectile dysfunction (mean age 50 +/- 8 years, range 38-64). All patients were receiving therapy with calcineurin inhibitors (5 with cyclosporine and 4 with tacrolimus). Erectile dysfunction was evaluated by clinical history, physical examination, International Index of Erectile Function (IIEF) questionnaire and the nocturnal penile tumescence test (RigiScan). Each patient received a first dose of 50 mg of sildenafil, one hour before sexual activity and a second dose at 72 hours of 50 or 100 mg according to the clinical response to the first dose. We evaluated the efficacy and safety of sildenafil and the evolution of cyclosporine-tacrolimus levels. Cyclosporine and tacrolimus trough whole blood concentrations were determined in basal conditions (before starting sildenafil) and on days 1, 4 and 7 after sildenafil therapy.

RESULTS

Eighty-nine percent of patients (n = 8) required a complete 100 mg dose of sildenafil. There was a positive clinical response in two-thirds of cases (6 patients). In 5 patients (55%) sildenafil administration produced a complete response, in one patient the response was incomplete, and in the remaining 3 cases (33%) no clinical response was observed. Associated side effects included self-limited tachycardia in one patient and mild visual disturbances in another. Cyclosporine and tacrolimus levels remained stable in all patients. There were no significant differences in circulating levels of cyclosporine (basal 120 +/- 47; day 1: 116 +/- 55; day 4: 123 +/- 56 and day 7: 121 +/- 56 ng/ml p = NS) or tacrolimus (basal 11.6 +/- 1.3; day 1: 11.9 +/- 1.3; day 4: 11.1 +/- 1.0 and day 7: 11.8 +/- 0.9 ng/ml p = NS) over the study period.

CONCLUSIONS

Sildenafil therapy is safe and effective for the treatment of erectile dysfunction in renal transplant recipients. Recommended therapeutic doses of sildenafil did not modify cyclosporine and tacrolimus trough blood levels.

[Atypical cytomegalovirus in renal transplantation: a new form of presentation]

Infection due to cytomegalovirus (CMV) is the most frequent opportunistic infection following renal transplantation (RT). It is usually asymptomatic. Cytomegalovirus disease causes fever leucopenia, thrombocytopenia and slightly elevated transaminases. The development of severe invasive forms is uncommon nowadays with post-transplantation monitoring, prophylactic regimens in high-risk patients and early treatment with ganciclovir. We report two renal transplant recipients who presented with severe gastrointestinal bleeding as the first manifestation of CMV disease at 9 and 14 weeks after transplantation. In both patients repeated post-transplantation pp65 antigenemia monitoring was negative. One patient developed hypovolemic shock due to severe rectal bleeding; an atypical bleeding ulcer was detected in the ileocecal valve. The other patient presented with upper gastrointestinal hemorrhage from a bleeding duodenal ulcer. Histological and immunohistochemical study confirmed the diagnosis. Both patients were elderly and on triple therapy with tacrolimus, mycophenolate and prednisone. We discuss the role of mycophenolate and the new immunosuppressant agents as factors favoring a state of enhanced immunosuppression, which may facilitate the onset of severe atypical forms of CMV disease.