Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42345 (mTOR)
 26,049 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mTOR inhibitor sirolimus improves renal transplant function compared with the nephrotoxic calcineurin inhibitors. We evaluated retrospectively the adverse events in 119 of 134 patients getting sirolimus which seemed to be caused by sirolimus. Patients were converted to sirolimus because of malignancies (n = 47), a creeping creatinine (n = 33), or hypertension (n = 26). One cohort had started sirolimus from the time of transplantation (n = 28). A rise in serum lipids and a decrease in hemoglobin were seen relatively regularly, while arthralgia, peripheral edema, gastrointestinal complaints, skin disorders, electrolyte disturbances, and infections occurred only occasionally. Interestingly, 31% of patients developed doubling or more proteinuria. Among renal biopsies, 9/13 showed a glomerulopathy which in 6 cases was de novo and in 3 cases, a presumed recurrence of the primary kidney disease. Thus, we think that caution is required, particularly in connection with preexisting glomerular disease.
 ...
PMID:Side effects of sirolimus. 1664 52

Everolimus is a proliferation signal inhibitor (PSI)/mammalian target of rapamycin inhibitor that is structurally similar to sirolimus, but with a number of important pharmacokinetic differences, including a shorter half-life and time to steady state. In clinical trials, the efficacy of everolimus 1.5 mg/day and 3.0 mg/day combined with ciclosporin (CsA) and steroids in de novo renal transplant recipients is similar to that of mycophenolate mofetil, with one study showing a significantly lower risk of antibody-treated acute rejection with everolimus. When combined with reduced-dose CsA, everolimus is associated with improved renal function compared with full-dose CsA, with no decrease in efficacy. Thus, everolimus may play an important role in calcineurin inhibitor (CNI)-sparing regimens for renal transplant recipients. Studies with sirolimus have shown that CNI withdrawal is associated with a significant improvement in renal function, although there may be an increase in the risk of acute rejection. however, patient and graft survival are not adversely affected by CNI withdrawal. Notably, proteinuria <800 mg/day before conversion is a strong predictor of successful response to sirolimus treatment, and hypertensive therapy and serum lactate dehydrogenase levels may also predict response. Adverse events commonly associated with the PSIs include dyslipidaemia, proteinuria and anaemia, although these can usually be managed without difficulty. Data are also available to suggest that the PSIs are associated with a lower risk of malignancy than other immunosuppressive agents. In conclusion, everolimus may permit reduced exposure to CNIs in renal transplant recipients, with the potential to improve tolerability and renal function.
 ...
PMID:Everolimus in clinical practice--renal transplantation. 1681 52

Calcineurin inhibitors (CNIs) are associated with important side effects, such as nephrotoxicity, and thus there is an interest in developing CNI-sparing protocols using agents such as the proliferation signal inhibitor/mammalian target of rapamycin inhibitor everolimus. In a 3-month pilot study using an abrupt conversion protocol, ciclosporin (CsA) treatment was stopped after the morning dose and everolimus was started at 3.0 mg/day. Mycophenolic acid (MPA)-based therapy was continued, or prednisolone increased to 10 mg/day until target everolimus trough blood levels (3-8 ng/ml) were achieved. To date, seven patients have been enrolled, with three having completed at least 3 months of follow-up. Overall, conversion was effective and well-tolerated. Patients consistently achieved everolimus trough blood levels >3 ng/ml, and no episodes of acute rejection or proteinuria were reported after 3 months. In patients who completed the study, there were no major changes in the leucocyte or platelet counts during everolimus treatment. Serum creatinine levels were maintained or decreased slightly. One patient experienced a transient increase in serum creatinine during an episode of pneumonia, but levels decreased again after resolution of infection and temporary everolimus dose reduction. Serum cholesterol and triglyceride levels increased, but remained within acceptable limits. One patient receiving enteric-coated mycophenolate sodium 1440 mg/day experienced increasing everolimus trough blood levels and anaemia after conversion, and was therefore likely to have been over-immunosuppressed. Abrupt conversion to everolimus from CsA was effective and well-tolerated in renal transplant recipients. A reduction in MPA dosage at the time of conversion may be necessary to prevent over-immunosuppression.
 ...
PMID:Conversion to everolimus in maintenance patients--current clinical strategies. 1681 53

Mycophenolate mofetil (MMF) and sirolimus (SRL) are potent non-nephrotoxic xenobiotic immunosuppressants. Their complementary properties may provide the rationale for their combination in induction and maintenance regimens. MMF, a reversible inhibitor of inosin monophosphate dehydrogenase (IMPDH) acts as an antiproliferative drug; and SRL, an mTOR (mammalian target of rapamycin) inhibitor, inhibits cell proliferation driven by growth factors. Early experiences with the use of the SRL, MMF and steroid combination yielded insufficient prophylaxis of acute rejection. However, the introduction of induction therapy with mono- or polyclonal antilymphocyte antibodies to the SRL-MMF and steroid combination brings an efficient acute rejection prophylaxis, while improving renal function and/or reducing of chronic allograft nephropathy (CAN). However, adverse events related to the use of this drug combination (mainly haematological and surgery-related) result in a high rate of discontinuations in some trials, which may hamper the potential benefits of this calcineurin-inhibitor (CNI)-free strategy. Also, currently under investigation is whether in long-term immunosuppression, in MMF-treated patients, CNIs can be replaced by SRL to avoid and/or halt progression of chronic nephropathy and to improve graft survival. However, some authors reported a high proportion of patients with oral ulcers and proteinuria after switching to SRL. In short, refining the use of MMF and SRL may provide a better risk/benefit ratio to pave the way towards non-nephrotoxic immunosuppression.
 ...
PMID:Mycophenolate mofetil and sirolimus combination in renal transplantation. 1693 Mar 95

Sirolimus is a novel immunosuppressant with potent antiproliferative actions through its ability to inhibit the raptor-containing mammalian target of rapamycin protein kinase. Sirolimus represents a major therapeutic advance in the prevention of acute renal allograft rejection and chronic allograft nephropathy. Its role in the therapy of glomerulonephritis, autoimmunity, cystic renal diseases and renal cancer is under investigation. Because sirolimus does not share the vasomotor renal adverse effects exhibited by calcineurin inhibitors, it has been designated a 'non-nephrotoxic drug'. However, clinical reports suggest that, under some circumstances, sirolimus is associated with proteinuria and acute renal dysfunction. A common risk factor appears to be presence of pre-existing chronic renal damage. The mechanisms of sirolimus-associated proteinuria are multifactorial and may be due to an increase in glomerular capillary pressure following calcineurin inhibitor withdrawal. It has also been suggested that sirolimus directly causes increased glomerular permeability/injury, but evidence for this mechanism is currently inconclusive. The acute renal dysfunction associated with sirolimus (such as in delayed graft function) may be due to suppression of compensatory renal cell proliferation and survival/repair processes. Although these adverse effects occur in some patients, their occurrence could be minimised by knowledge of the molecular effects of sirolimus on the kidney, the use of sirolimus in appropriate patient populations, close monitoring of proteinuria and renal function, use of angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers if proteinuria occurs and withdrawal if needed. Further long-term analysis of renal allograft studies using sirolimus as de novo immunosuppression along with clinical and laboratory studies will refine these issues in the future.
 ...
PMID:Sirolimus-associated proteinuria and renal dysfunction. 1714 61

Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor that inhibits cell cycle progression and has proven to be a potent immunosuppressive agent for use in solid organ transplant recipients. The drug was initially studied as an adjunct to ciclosporin (cyclosporine) to prevent acute rejection in kidney transplant recipients. Subsequent studies have shown efficacy when combined with a variety of other immunosuppressive agents. The most common adverse effects of sirolimus are hyperlipidaemia and myelosuppression. The drug has unique antiatherogenic and antineoplastic properties, and may promote immunological tolerance and reduce the incidence of chronic allograft nephropathy. Although sirolimus is relatively non-nephrotoxic when administered as monotherapy, it pharmacodynamically enhances the toxicity of calcineurin inhibitors. Ironically, the drug has been used to facilitate calcineurin inhibitor-free protocols designed to preserve renal function after solid organ transplantation. Whether sirolimus can be used safely over the long term with low doses of calcineurin inhibitors requires further study. The use of sirolimus as a corticosteroid-sparing agent also remains to be proven in controlled trials. Postmarketing studies have revealed a number of unforeseen adverse effects including impaired wound healing and possibly proteinuria, oedema, pneumonitis and thrombotic microangiopathy. Overall, sirolimus is a powerful agent when used judiciously with other available immunosuppressants. As is true for all immunosuppressive drugs available for treatment of solid organ transplant recipients, the efficacy of the drug must be balanced against its considerable adverse effects.
 ...
PMID:Use of sirolimus in solid organ transplantation. 1733 96

Diagnosis and treatment of autosomal dominant polycystic kidney disease (ADPKD) is rapidly changing. Cellular pathways that involve the polycystins are being mapped and involve the primary cilium, intracellular calcium and cAMP regulation, and the mammalian target of rapamycin (mTOR) pathway. With the use of new imaging approaches, earlier diagnosis of hepatic cystic disease is possible, and measurement of kidney and cystic growth as well as kidney blood flow is possible over relatively short periods. PKD gene type, gender, proteinuria, and the presence of hypertension relate to the rate of kidney growth in ADPKD. On the basis of risk factors for progression to ESRD and the pathogenic roles that intracellular cAMP and mTOR play in cystogenesis, novel therapies are now being tested, including maximal inhibition of the renin-angiotensin system, inhibition of renal intracellular cAMP using vasopressin V2 receptor antagonists, and somatostatin analogues, as well as inhibitors of mTOR. This review addresses the current understanding of the pathogenesis and the natural history of ADPKD; accuracy and reliability of diagnostic approaches in utero, childhood, and adulthood; the value of reliable magnetic resonance imaging to measure disease progression early in the course of ADPKD; and novel therapeutic approaches that are being evaluated in ADPKD.
 ...
PMID:Autosomal dominant polycystic kidney disease: time for a change? 1742 47

New immunosuppressive agents are being actively researched to avoid complications of chronic allograft nephropathy (CAN), calcineurin inhibitor (CNI) nephrotoxicity, and posttransplantation cancer. The family of mTOR inhibitors offers a unique immunosuppressive opportunity to avoid CNI toxicity and reduce the incidence of malignancy. Nevertheless, increasing data have demonstrated that sirolimus (SRL), the first mTOR introduced in the treatment of solid organ transplant recipients, induces proteinuria, an adverse event that could produce deterioration of long-term renal function. In this short-term study of patients followed for 1 to 16 months, we examined changes in renal function and proteinuria among renal transplant recipients converted from a CNI-based regimen to an everolimus (EVL)-based one, a recently introduced mTOR inhibitor. Our data showed that renal function can be optimized after conversion to EVL by up to 42% in recipients showing CAN grade 1 or 2, or CNI nephrotoxicity. Importantly, patients who improved their creatinine clearance did not show increased proteinuria measured in a voided specimen as the ratio of urinary protein and creatinine concentration (P/C). These results, if confirmed with long-term follow-up and a larger number of patients, would allow us to consider EVL as a promising agent for maintenance immunosuppressive regimens in kidney transplantation.
 ...
PMID:Conversion from a calcineurin inhibitor-based immunosuppressive regimen to everolimus in renal transplant recipients: effect on renal function and proteinuria. 1744 51

Many kidney transplant patients experience an increase in proteinuria when converted from a calcineurin inhibitor-based regimen to one based on a mammalian target of rapamycin (mTOR) inhibitor, and preexisting proteinuria and poor renal function have been identified as risk factors for this increase. Our aim was to evaluate the effect of sirolimus, an mTOR inhibitor, on renal function and histology in a proteinuric model of reduced renal mass. Sirolimus-treated animals had approximately half as much proteinuria as vehicle-treated animals (P < 0.05), and had less glomerulosclerosis, tubular atrophy, interstitial fibrosis, and inflammation. Immunohistochemistry showed that sirolimus attenuated the increased expression of renal vascular endothelial growth factor (VEGF), as well as the expression of VEGF receptors 1 and 2. In conclusion, sirolimus halted the progression of proteinuria and structural damage in a rat model of reduced renal mass, possibly through a reduction in renal VEGF activity.
 ...
PMID:Mammalian target of rapamycin inhibition halts the progression of proteinuria in a rat model of reduced renal mass. 1780 74

Sirolimus is a new immunosuppressive drug used to avoid allograft rejection. The immunosuppressive effect of sirolimus is due to inhibition of the mammalian target of rapamycin, necessary for the proliferation and clonal expansion of activated T-cells. Because T-cells play a central role in the pathogenesis of autoimmune disease developed in (NZBxNZW)F1 mice, we evaluated the therapeutic use of sirolimus in such mice. (NZBxNZW)F1 female mice received 1mg/kg/day of sirolimus from 12 to 37 weeks of age. The development of autoimmune disease was evaluated by measuring the serum levels of auto-antibodies (autoAbs) and their immunoglobulin isotypes, prevalence of glomerulonephritis and mortality rates. Sirolimus directly inhibited production of autoAbs, glomerular deposits of immunoglobulins and development of proteinuria; also the survival of these mice was prolonged. Our results demonstrate the beneficial effects of sirolimus in preventing the development of lupus disease in (NZBxNZW)F1 female mice.
 ...
PMID:Prevention of murine lupus disease in (NZBxNZW)F1 mice by sirolimus treatment. 1789 99


1 2 3 4 5 6 7 8 9 10 Next >>