Showing papers by "Mercè Brunet published in 2010"

Interaction Between Everolimus and Tacrolimus in Renal Transplant Recipients: A Pharmacokinetic Controlled Trial

Abstract: BACKGROUND Clinical data are lacking concerning therapeutic action and systemic exposure of tacrolimus (TAC) and everolimus (EVL) in a combined regimen in renal transplantation. METHODS A prospective randomized phase II pharmacokinetic study was conducted comparing two fixed EVL dosages (0.75 mg two times per day (BID), group A, or 1.5 mg BID, group B) in combination with standard TAC dose. Complete 12-hr pharmacokinetic curves of both drugs were performed at days 4, 14, and 42 posttransplant. RESULTS A higher TAC Cmin was observed with EVL dose of 0.75 mg BID (TAC 11.1+/-6.4 group A vs. 9.4+/-5.0 ng/mL group B, P=0.03), with equivalent TAC area under the curves (162+/-61 vs. 171+/-75). The exposure to TAC was lower in group B despite higher TAC doses were required to maintain target concentrations (day 14: 9.5 vs. 12.5 mg and day 42: 6 vs. 9 mg, P<0.05). Cmin-TAC/dose and area under the curve-TAC/dose ratios were significantly lower, from day 4 to day 42, in group B. Both groups achieved good graft function and acute rejection rate was similar (20% and 15%, respectively). CONCLUSIONS We conclude that in adult renal transplant recipients, EVL significantly decreases TAC oral bioavailability in a dose-dependent manner. Doses higher than 1.5 mg BID would be probably needed for TAC-minimization strategies because 3 mg/day is not enough to achieve levels more than 3 ng/mL during the first 2 weeks. Therapeutic drug monitoring is mandatory to adjust the dose and prevent low TAC exposure. This regimen of low EVL exposure plus standard TAC exposure avoids wound healing problems with good efficacy.

Biomarker assessment of the immunomodulator effect of atorvastatin in stable renal transplant recipients and hypercholesterolemic patients.

Abstract: Background: HMG-CoA reductase inhibitors (statins) have effects beyond lipid lowering, including immunomodulatory and anti-inflammatory properties. Statins are frequently combined with immunosuppressive agents in transplant recipients to modulate the hyperlipidemic side effects of the immunosuppressants. However, the role of statins in the immunosuppressive response that is achieved in individual patients remains to be assessed. Objective: The aim of this study was to evaluate the immunomodulatory effect of atorvastatin given alone and in combined treatment with tacrolimus and mycophenolate mofetil. Study Design: Two patient groups were studied: renal transplant recipients receiving tacrolimus and mycophenolate mofetil therapy, and hypercholesterolemic patients (the control group). Fasting blood samples were taken from participants before and 1 month after atorvastatin treatment was started to study a small battery of biomarkers that are able to reflect the range of the effects of immunosuppressive therapy and atorvastatin. Setting: All patients in the study were enrolled at the Hospital Clinic of Barcelona. Patients: All patients enrolled in the study were candidates for treatment with atorvastatin because of high cholesterol levels. One group consisted of 25 stable renal transplant recipients with low-density lipoprotein (LDL) cholesterol levels above 100mg/dL after 3 months of therapeutic lifestyle changes, according to the guidelines of the National Kidney Foundation —Kidney Disease Outcomes Quality Initiative. The other group included 25 hypercholesterolemic patients with LDL cholesterol levels above target values for the patients’ overall risk, as derived from the National Cholesterol Education Program Adult Treatment Panel III criteria. Intervention: Atorvastatin (Lipitor®) treatment was started at a fixed dose of 20 mg daily. Main Outcome Measure: The studied biomarkers were lymphocyte proliferation, intracellular adenosine triphosphate (ATP) synthesis in CD4+ T cells, intralymphocytary cytokine expression (interleukin [IL]-2, interferon [IFN]-γ), soluble cytokine production (IL-2, IFN-γ, IL-10, IL-17, and transforming growth factor-β) and regulatory T (Treg) cells. Results: Atorvastatin proved to be an immunomodulatory agent, significantly decreasing lymphocyte proliferation by 15% (p = 0.001), increasing ATP levels by 16% (p = 0.0004), and showing a trend toward increasing Treg cells in hypercholesterolemic patients (p = 0.09). In the renal transplant recipients, atorvastatin therapy did not modify any of the biomarkers of immunosuppression that were studied. Conclusion: Atorvastatin showed immunoregulatory effects on T cells in hypercholesterolemic patients. These effects were absent in renal transplant recipients, suggesting that the beneficial effects of atorvastatin in this patient group do not relate to immunoregulation. Therefore, statin treatment cannot be considered as a means to reduce the dose of immunosuppressive agents.