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C Legendre

Publications and source records attributed to C Legendre.

At least 19 recordsLinked to original sources
PubMed2006

Role of P-glycoprotein in cyclosporine cytotoxicity in the cyclosporine-sirolimus interaction.

Cyclosporine nephrotoxicity remains a major side effect in solid organ transplantation, and can be exacerbated by concomitant administration of sirolimus. Cyclosporine and sirolimus are P-glycoprotein (Pgp) substrates. We hypothesized that the Pgp activity level may affect cyclosporine cytotoxicity by interfering with the ability of Pgp to remove cyclosporine from within tubular cells, and that an interaction between cyclosporine and sirolimus on Pgp function may explain the enhancement of cyclosporine nephrotoxicity by sirolimus. Cyclosporine cytotoxicity was evaluated in primary cultures of normal human renal epithelial cells (HRECs) by cell viability and cytotoxicity assays. Verapamil, quinine, PSC833, and PGP-4008 were used as Pgp inhibitors. Rhodamine-123 (R-123), a fluorescent substrate of Pgp, was used to assess Pgp-mediated transport. Cellular cyclosporine concentration was measured by high-performance liquid chromatography coupled to tandem mass spectrometry. Pgp expression and function were confirmed in HRECs and cyclosporine and sirolimus were shown to be Pgp inhibitors in this model. Verapamil-induced inhibition of Pgp led to a significant increase in cellular concentration of cyclosporine (P<0.05). Cyclosporine exerted a concentration-dependent cytotoxic effect on HRECs that was significantly increased by inhibition of Pgp activity. Sirolimus exerted an inhibitory effect on R-123 efflux in HRECs and increased cellular cyclosporine concentrations in a dose-dependent manner. These data demonstrate that Pgp plays a critical role in protecting renal epithelial cells from cyclosporine toxicity. The inhibitory effect of sirolimus on Pgp-mediated efflux and the cellular concentration of cyclosporine could explain the exacerbation of cyclosporine nephrotoxicity observed clinically.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2006

Sirolimus conversion for patients with posttransplant Kaposi's sarcoma.

This retrospective study aimed to evaluate the benefit of switching from calcineurin inhibitors (CnI) to sirolimus in posttransplant Kaposi's sarcoma (KS). Fourteen patients monitored in five French departments who had developed posttransplant KS were switched from CnI to sirolimus either abruptly (n=9) or progressively (n=5) with trough levels 5-12 ng/mL. Two patients had a complete remission, eight a partial response, and five no significant improvement of KS. The mean time to response was 3.9 months. After a mean follow-up of 16 months, 3 partial responders, with previous severe and refractory KS, suffered again from KS progression despite the lack of concomitant infectious or neoplastic event. These relapses occurred 5-9 months after switching. The tolerance of sirolimus has been excellent except for in one patient who developed severe interstitial pneumonitis. Sirolimus is usually useful in the management of posttransplant KS. It may be, however, ineffective or transiently effective in some patients with severe KS. Prospective studies with pharmacodynamic evaluation are important in order to better assess the duration of responses and the mechanisms of primary and acquired drug resistance.

Adult↗
PubMed2006

Surgical treatment of destructive cervical spondyloarthropathy with neurologic impairment in hemodialysis patients.

STUDY DESIGN: We have retrospectively reviewed 11 chronic hemodialysis patients with cervical destructive spondyloarthropathy responsible for neural impairment 1 year after surgery and at last follow-up. OBJECTIVE: To evaluate clinical and radiologic outcomes, and necessity of vertebral block excision. SUMMARY OF BACKGROUND DATA: Destructive spondyloarthropathy of the cervical spine is associated with long-term hemodialysis for chronic kidney failure. Spinal cord compression and neurologic troubles occur in a few cases. Surgical treatment remains controversial because these are debilitated patients with multiple organ failures. METHODS: All 11 patients had unstable cervical spondylolisthesis, and 10 had kyphotic vertebral fusion involving at least 2 vertebrae. We performed interbody bone grafting (cement in 1 case) and stabilized with a plate. In 6 of the 10 patients with vertebral block, excision of the block was performed. RESULTS: No patients were lost to follow-up. One patient died 2 days after the operation. There were 2 other patients who required early surgical revision (i.e., a corporectomy followed by early graft expulsion). Bone healing settled in all patients. One year after surgery, patients had almost complete resolution of the pain and satisfactory neurologic recovery. Improvement was evaluated according to the Nurick classification. CONCLUSION: Functional and neurologic results were similar whether the patients did or did not undergo vertebral block excision, suggesting that stabilizing the unstable level may be sufficient in patients with neurologic impairment. Excision of spontaneous vertebral blocks should be avoided to minimize the morbidity of surgery in these debilitated patients with a limited life expectancy.

Aged↗
PubMed2006

Tolerability of enteric-coated mycophenolate sodium to 1 year in combination with cyclosporine and corticosteroids in renal transplant recipients.

Enteric-coated mycophenolate sodium (EC-MPS) is therapeutically equivalent to mycophenolate mofetil, but delays release of mycophenolic acid until it reaches the small intestine. De novo renal transplant patients taking part in a 12-month, multicenter, randomized study received cyclosporine microemulsion (CsA-ME, early or delayed to day 6), EC-MPS, steroids, and interleukin-2 antagonist induction. Tolerability data relating to EC-MPS are reported. Ninety-seven patients were randomized to early CsA-ME and 100 patients to delayed CsA-ME. Median daily dose of EC-MPS was 1440 mg at all time points throughout the 12-month period. The most frequently reported adverse events were constipation, anemia, urinary tract infection, abdominal pain, leukopenia, and cytomegalovirus infection; there were four malignancies. Fifty patients (24.6%) discontinued EC-MPS prematurely by 12 months, including 42 patients (84%) who discontinued owing to adverse events. No patient discontinued treatment because of gastrointestinal adverse events. Two-thirds of patients (137 [67.5%]) maintained full EC-MPS dose throughout the 12-month study and did not require any dose reduction or dose interruption. EC-MPS is well tolerated in de novo renal transplant recipients when administered in combination with CsA-ME and steroids, with low rates of dose reductions or interruptions. Gastrointestinal adverse events were responsible for dose reduction or interruption in only 5% of patients.

Adrenal Cortex Hormones↗
PubMed2006

Clinical operational tolerance after kidney transplantation.

Induction of allograft-specific tolerance and the detection of a "tolerance" state in recipients under immunosuppression with long-term stable graft function are major challenges in transplantation. Clinical "operational tolerance," defined as stable and acceptable graft function without immunosuppression for years, is a rare event. There is no report on the clinical history of such patients. In this article, we report on the medical history of 10 kidney recipients who display an immunosuppressive drug-free "operational tolerance" for 9.4 +/- 5.2 years. Clinical factors that may favor such a tolerant state are underlined. Firstly, most of the patients interrupted immunosuppression over a long time period (until 4 years), which mimics the procedure of intentional immunosuppression weaning following liver transplantation. Secondly, donor age was younger (median 25 years) than the one of the general transplanted population, suggesting that graft quality is one of the conditions favoring "operational tolerance." Moreover, the "operationally tolerant" recipients may be 'low responders' to blood transfusions (PRA 6 +/- 5.4%, six blood transfusions). We also show that "operational tolerance" occurs in the presence of anti-donor class II antibodies, as assessed in two patients. Finally, two patients degraded their renal function 9 to 13 years after treatment withdrawal, however only one presented histological lesions of chronic rejection.

Aged↗
PubMed2006

Impact of early or delayed cyclosporine on delayed graft function in renal transplant recipients: a randomized, multicenter study.

The benefit of delayed cyclosporine in reducing risk of delayed graft function (DGF) is not clearly established. This study compared early vs. delayed cyclosporine microemulsion (CsA-ME) inde novorenal transplant patients. Patients were randomized to early (day 0, n=97) or delayed (day 6, n=100) CsA-ME at an initial dose of 8 mg/kg/day with dose adjusted according to C2 level. All patients received enteric-coated mycophenolate sodium (EC-MPS), steroids and an anti-interleukin-2 receptor antibody. In both groups, 33% of patients were at high risk of DGF; 26 patients (26.8%) in the early CsA-ME group and 23 patients (23.0%) in the delayed CsA-ME group experienced DGF (n.s.). Renal function at 3 months was comparable (creatinine clearance 51.1 mL/min with early CsA-ME and 53.8 mL/min with delayed CsA-ME), and remained similar to 12 months. Treatment failure, defined as biopsy-proven acute rejection, graft loss or death, did not differ significantly at 12 months (23.7% with early CsA-ME vs. 29.0% with delayed CsA-ME). Biopsy-proven acute rejection occurred in 15.5% of early CsA-ME and 26.5% of delayed CsA-ME patients (n.s.). Both regimens were well tolerated. These data suggest that early or delayed introduction of CsA-ME results in similar renal function in renal transplant patients regardless of DGF risk level.

Adult↗
PubMed2005

[Sirolimus-associated interstitial pneumonitis in a renal transplant patient].

INTRODUCTION: Sirolimus is a new immunosuppressive drug used in organ transplantation, particularly in renal transplantation. In the future, it could replace calcineurin inhibitors such as cyclosporine. It is currently associated with side effects, such as thrombocytopenia and hyperlipidemia. Several interstitial pneumonitis associated with sirolimus has been previously described in renal transplant recipients associated with marked general symptoms. EXEGESIS: We report on a 65-year-old renal recipient presenting with a non typical case of sirolimus interstitial pneumonitis. He presented with fever and marked general symptoms for several months. CT scan showed a unilateral interstitial pneumonitis. After infectious, inflammatory and tumoral diseases were ruled out, sirolimus associated interstitial pneumonitis was evoked. The patient improved quickly after discontinuation of sirolimus. CONCLUSION: It is important to evoke, after eliminating other aetiologies, sirolimus induced pneumonitis in face of an organ transplant recipient presenting with marked general symptoms even if the pulmonary symptoms are not predominant.

Aged↗
PubMed2004

Detection of ganciclovir resistance after valacyclovir-prophylaxis in renal transplant recipients with active cytomegalovirus infection.

Whether valaciclovir (VCV) prophylaxis could be responsible for ganciclovir (GCV)-resistance of Human cytomegalovirus (HCMV) in transplantation has never been documented. A multicentric retrospective pilot study was undertaken to detect GCV-resistance through mutations within the UL97 gene in renal transplant recipients who experienced active HCMV infection and received valacyclovir prophylaxis. Twenty-three patients who experienced HCMV antigenaemia or DNAemia during or at the end of prophylaxis were included. UL97 genotyping was carried out on peripheral blood samples, using a nested in-house PCR, which amplified the full-length UL97 gene. One patient has a resistance-related mutation (M460I); the major risk factor for emergence of resistance in this patient was the presence of early and persistent antigenaemia. GCV-resistance during VCV-prophylaxis was rare after renal transplantation. However, special attention must be paid to patients developing early active HCMV infection under prophylaxis.

Acyclovir↗
PubMed2004

[A rare cause of pulmonary-renal syndrome with autoantibodies: primary antiphospholipid syndrome].

We present a case of primary antiphospholipid syndrome with acute renal failure and alveolar haemorrhage. He was successfully treated with cyclophosphamide, corticosteroids and plasma exchange. Patients with antiphospholipid syndrome may develop a broad spectrum of pulmonary disease. Pulmonary thromboembolism and pulmonary hypertension are the most common complications, but alveolar haemorrhage have also been reported. Other causes need to be excluded. Despite favourable outcome of many patients with association of plasma exchange, immunosuppressive drugs and anticoagulant therapy, definite conclusions about the best therapeutic regimen could not be draw.

Acute Kidney Injury↗
PubMed2003

[Preoperative selective embolization allowing a partial splenectomy for splenic hamartoma].

PURPOSE OF THE STUDY: To underline value of the preoperative splenic embolization with haemostatic aim to facilitate partial splenectomy. MATERIAL: Observation of a 23-year-old woman, admitted for pain, anemia, and mass of the left hypochondrium. Sonography, helical CT and MRI showed that the bulky mass was developed from the upper pole of spleen, and dislodged the left kidney towards the pelvis. This mass had fibrous characteristics in favour of a primary lesion with recent bleeding and was compatible with a splenic hamartoma. METHODS: Selective partial splenic embolization with haemostatic aim using metal coils, immediately followed by surgery. RESULTS: Preoperative embolisation made possible to carry out under optimal surgical conditions a partial splenectomy with en-bloc resection of the splenic mass. Histologic diagnosis was splenic hamartoma of pulpar type. CONCLUSION: This case illustrates the interest of accurate characterization of splenic lesions by several imaging techniques allowing indication for conservative surgery, and of preoperative embolization facilitating a partial splenectomy.

Adult↗
PubMed2003

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.

Cardiovascular Diseases↗
PubMed2001

A randomized, double-blind trial of basiliximab immunoprophylaxis plus triple therapy in kidney transplant recipients.

BACKGROUND: A double-blind, placebo-controlled, randomized study was performed to assess whether immunoprophylaxis with basiliximab (Simulect) could reduce the incidence of acute rejection in kidney transplant recipients treated with cyclosporine (Neoral), steroids, and azathioprine. METHODS: Three hundred forty patients received either placebo or basiliximab at a dose of 20 mg, given intravenously on days 0 and 4. All patients received cyclosporine, steroids, and azathioprine. The primary endpoint was the incidence of acute rejection at 6 months. Secondary endpoints included the safety and tolerability of basiliximab and placebo, 1-year patient and graft survival, and significant medical events up to 12 months. RESULTS: During the first 6 months posttransplantation, acute rejection occurred in 20.8% of patients given basiliximab versus 34.9% of patients administered placebo (P=0.005). Similarly, there was a reduction in biopsy-proven acute rejection at 6 months in the patients receiving basiliximab (P=0.023). One-year patient survival was 97.6% with basiliximab and 97.1% with placebo, graft survival was 91.5% versus 88.4%, respectively (NS). The adverse-events profile of patients treated with basiliximab was indistinguishable from that of patients treated with placebo. The number of patients with infections was similar (65.5% for basiliximab vs. 65.7% for placebo), including cytomegalovirus infections (17.3% vs. 14.5%, P=0.245). Nine neoplasms (three in the basiliximab group, six in the placebo arm) were recorded up to 1 year from transplantation. CONCLUSIONS: Basiliximab in combination with cyclosporine, steroids, and azathioprine triple therapy was highly effective in reducing the incidence of acute renal allograft rejection without increasing the incidence of infections and other side effects.

Adult↗
PubMed2001

Induction versus noninduction in renal transplant recipients with tacrolimus-based immunosuppression.

BACKGROUND: The aim of this study was to compare the efficacy and safety of induction treatment with antithymocyte globulins (ATG) followed by tacrolimus therapy with immediate tacrolimus therapy in renal transplant recipients. METHODS: This 12-month, open, prospective study was conducted in 15 centers in France and 1 center in Belgium; 309 patients were randomized to receive either induction therapy with ATG (n=151) followed by initiation of tacrolimus on day 9 or immediate tacrolimus-based triple therapy (n=158). In both study arms, the initial daily tacrolimus dose was 0.2 mg/kg. Steroid boluses were given in the first 2 days and tapered thereafter from 20 mg/day to 5 mg/day. Azathioprine was administered at 1-2 mg/kg per day. RESULTS: At month 12, biopsy-confirmed acute rejections were reported for 15.2% (induction) and 30.4% (noninduction) of patients (P=0.001). The incidence of steroid-sensitive acute rejections was 7.9% (induction) and 22.2% (noninduction)(P=0.001). Steroid-resistant acute rejections were reported for 8.6% (induction) and 8.9% (noninduction) of patients. A total of nine patients died. Patient survival and graft survival at month 12 was similar in both treatment groups (97.4% vs. 96.8% and 92.1% vs. 91.1%, respectively). Statistically significant differences in the incidence of adverse events were found for cytomegalovirus (CMV) infection (induction, 32.5% vs. noninduction, 19.0%, P=0.009), leukopenia (37.3% vs. 9.5%, P<0.001), fever (25.2% vs. 10.1%, P=0.001), herpes simplex (17.9% vs. 5.7%, P=0.001), and thrombocytopenia (11.3% vs. 3.2%, P=0.007). In the induction group, serum sickness was observed in 10.6% of patients. The incidence of new onset diabetes mellitus was 3.4% (induction) and 4.5% (noninduction). CONCLUSION: Low incidences of acute rejection were found in both treatment arms. Induction treatment with ATG has the advantage of a lower incidence of acute rejection, but it significantly increases adverse events, particularly CMV infection.

Adult↗
PubMed2001

Preferential pharmacological inhibition of macrophage ACAT increases plaque formation in mouse and rabbit models of atherogenesis.

The cholesteryl ester, foam cell-enriched vulnerable plaque is a principle pharmacological target for reducing athero-thrombosis. Acyl CoA:cholesterol Acyl Transferase (ACAT) catalyzes the esterification of free cholesterol in intestine, liver, adrenal and macrophages, leading in the latter cells to intracellular cholesteryl ester accumulation and foam cell formation in the arterial intima. Previous studies suggested the existence of several isoforms of ACAT with different tissue distribution and this has largely been confirmed by molecular cloning of ACAT-1 and ACAT-2. We developed a series of ACAT inhibitors that preferentially inhibited macrophage ACAT relative to hepatic or intestinal ACAT based on in vitro assays and ex vivo bioavailability studies. Four of these compounds were tested in three models of atherosclerosis at oral doses shown to give sufficient bioavailable monocyte/macrophage ACAT inhibitory activity. In fat-fed C57BL/6 mice, chow fed apo E-/- mice and KHC rabbits, the various ACAT inhibitors had either no effect or increased indices of atherosclerotic foam cell formation. Direct and indirect measurements suggest that the increase in plaque formation may have been related to inhibition of macrophage ACAT possibly leading to cytotoxic effects due to augmented free cholesterol. These results suggest that pharmacological inhibition of macrophage ACAT may not reduce, but actually aggravate, foam cell formation and progression.

Anilides↗
PubMed2001

Differential influence of azathioprine and mycophenolate mofetil on the disposition of basiliximab in renal transplant patients.

Pharmacokinetic sampling was performed in two multicenter trials in which basiliximab (anti-CD25 monoclonal antibody) was administered with triple immunosuppression consisting of cyclosporine microemulsion, corticosteroids, and either azathioprine or mycophenolate mofetil. Blood samples were collected over 12 wk post-transplant from 31 azathioprine-treated and 66 mycophenolate mofetil-treated patients. Empirical Bayes estimates of each patient's basiliximab disposition parameters were derived and the duration of CD25 saturation was estimated as the time over which serum concentrations exceeded 0.2 microg/mL as confirmed by flow cytometry measurements. Basiliximab clearance was 29+/-14 mL/h when coadministered with azathioprine and 18+/-8 mL/h with mycophenolate mofetil. Both were significantly lower compared with a clearance of 37+/-15 mL/h from a previous study of basiliximab with dual therapy (p<0.001). As a consequence of the lower clearance of basiliximab, the durations of CD25 saturation were prolonged in the presence of azathioprine (50+/-20 d; range, 13--84) and mycophenolate mofetil (59+/-17 d; range, 28--94) compared with dual therapy (36+/-14 d; range, 12--91). A total of 27 acute rejection episodes occurred during the first 6 months in the two studies. Durations of CD25 saturation were not different in these patients compared with those who remained rejection-free in each study. A single patient among 57 who were screened developed anti-idiotype antibodies to basiliximab. The average duration of CD25 saturation was prolonged by 39 and 64% in the presence of azathioprine and mycophenolate mofetil, respectively. This graded effect was also observed for basiliximab clearance and may be due in part to a differentially reduced humoral response to basiliximab. Nonetheless, the range of CD25 saturation durations and basiliximab clearances did not extend outside the range when basiliximab was used with dual therapy in the absence of these agents. Hence, no dosing adjustment is deemed necessary when basiliximab is used in triple immunosuppressive therapy including either azathioprine or mycophenolate mofetil.

Antibodies, Anti-Idiotypic↗
PubMed2001

[New immunosuppressive drugs and diabetes].

Glucocorticoïds, calcineurin inhibitors (especially tacrolimus) and the combination of both are responsible for the occurrence of diabetes mellitus after organ transplantation. These drugs induce both insulin resistance and insulinopenia. Risks factors are well identified: high doses of immunosuppressive drugs, genetic background, age and weight excess. Long-term consequences seem to be as deleterious as those of other types of diabetes mellitus. Modulating the doses of immunosuppressive drugs is efficient in decreasing insulin requirement in transplant recipients but only individualization of immunosuppression taking risks factors into account will permit to decrease the incidence of this side-effect.

Diabetes Mellitus↗