Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chronic allograft nephropathy (CAN) is an anatomical and clinical alteration, characterized by proteinuria, hypertension and a progressive decline in kidney function, which begins at variable times (months, years) and can lead to the loss of the transplanted organ. CAN pathogenesis, which remains to be fully clarified, involves both immunological (early acute rejection, hyperimmunization, HLA-mismatches between donor and recipient, suboptimal immunosuppression, etc) and non-immunological factors (ischemia/reperfusion injury, reduced nephron mass, age differences between donor and recipient, dialysis time, hypertension, dislipidemia, proteinuria, etc). The possible prevention strategies for CAN consist of procedures aimed at the reduction of some potential risk factors: optimization of the conditions for organ explantation, diminution of ischemia/reperfusion injury, aggressive pharmacological treatment of acute rejection episodes, routine utilization of anti-hypertensive and hypolipidemic agents, and appropriate and rational immunosuppressive regimen. Moreover, some categories of immunosuppressive drugs, such as calcineurin inhibitors, can have a nephrotoxic effect, often regardless of therapeutic dosage. The introduction in clinical practice of novel immunosuppressive drugs with no nephrotoxicity, like mycophenolate mofetil and rapamycin, makes therapeutical strategies able to reduce the incidence of CAN feasible.
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PMID:[Therapy strategies in the prevention of chronic allograft nephropathy]. 1578

The crucial functions of atrial natriuretic peptide (ANP) and endothelial nitric oxide/NO in the regulation of arterial blood pressure have been emphasized by the hypertensive phenotype of mice with systemic inactivation of either the guanylyl cyclase-A receptor for ANP (GC-A-/-) or endothelial nitric-oxide synthase (eNOS-/-). Intriguingly, similar levels of arterial hypertension are accompanied by marked cardiac hypertrophy in GC-A-/-, but not in eNOS-/-, mice, suggesting that changes in local pathways regulating cardiac growth accelerate cardiac hypertrophy in the former and protect the heart of the latter. Our recent observations in mice with conditional, cardiomyocyte-restricted GC-A deletion demonstrated that ANP locally inhibits cardiomyocyte growth. Abolition of these local, protective effects may enhance the cardiac hypertrophic response of GC-A-/- mice to persistent increases in hemodynamic load. Notably, eNOS-/- mice exhibit markedly increased cardiac ANP levels, suggesting that increased activation of cardiac GC-A can prevent hypertensive heart disease. To test this hypothesis, we generated mice with systemic inactivation of eNOS and cardiomyocyte-restricted deletion of GC-A by crossing eNOS-/- and cardiomyocyte-restricted GC-A-deficient mice. Cardiac deletion of GC-A did not affect arterial hypertension but significantly exacerbated cardiac hypertrophy and fibrosis in eNOS-/- mice. This was accompanied by marked cardiac activation of both the mitogen-activated protein kinase (MAPK) ERK 1/2 and the phosphatase calcineurin. Our observations suggest that local ANP/GC-A/cyclic GMP signaling counter-regulates MAPK/ERK- and calcineurin/nuclear factor of activated T cells-dependent pathways of cardiac myocyte growth in hypertensive eNOS-/- mice.
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PMID:Local atrial natriuretic peptide signaling prevents hypertensive cardiac hypertrophy in endothelial nitric-oxide synthase-deficient mice. 1579 9

Liver transplant recipients are at risk of chronic renal failure (CRF), customarily considered to be secondary to CsA/FK506 nephrotoxicity. We have examined renal biopsies from 26 liver transplant recipients with CRF. Before OLT, 5 patients had CRF, 8 were diabetic and 9 hypertensive. Renal biopsies were performed at a mean of 5 years after liver transplantation. Mean SCr was then 212 micromol/L, proteinuria was 1 g/24 h. Twelve patients were diabetic and 25 hypertensive. Histology revealed impressive renal destruction, with a mean of 45% interstitial fibrosis and 45% glomerular sclerosis. All biopsies showed severe arteriosclerosis. CRF can be attributed to four associated primary lesions: (i) specific chronic CsA/FK506 arteriolopathy; (ii) typical diabetic nephropathy; (iii) acute or chronic thrombotic microangiopathy attributed to CsA/FK506 or alpha-IFN and (iv) tubular changes related to administration of hydroxyethylstarch. At the end of the follow-up, after a mean of 6.4 years, 12 patients required dialysis, 13 had CRF and only 1 had normal renal function. Thus, CRF in OLT recipients is more complex than originally thought and should not be classified as anti-calcineurin nephrotoxicity without further investigations, including renal histology. These investigations have therapeutic potential, that is, they may lead to a more aggressive treatment of hypertension and/or diabetes.
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PMID:Renal histopathological lesions after orthotopic liver transplantation (OLT). 1581 74

Reversible leukoencephalopathy syndrome (RLS) is a rare brain disorder, characterized by diffuse attenuation of cerebral white matter, which has been most commonly observed in transplant patients receiving calcineurin inhibitors or in patients with severe hypertension. We report an episode of RLS in a 22-year-old male patient on chronic hemodialysis with well-controlled moderate hypertension who presented with de novo headache and generalized seizures. Cranial magnetic resonance image (MRI) revealed multiple areas of increased signal intensity in the white matter on T2-weighed images which resolved spontaneously at subsequent MRIs. White blood cell count showed leucopenia with normal CD4 count at flow cytometry. A viral etiology could not be demonstrated. Reversible leukoencephaolopathy syndrome symptoms remitted within 72 h but leukopenia persisted over 10 months. The patient received a kidney transplant 15 months after RLS onset and has received cyclosporine since the second post-transplant day. No recurrence of RLS symptoms has been observed. The etiology of the MRI changes in the present case seemed not to be either vasogenic or cytotoxic.
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PMID:Reversible leukoencephalopathy syndrome associated to leukopenia in a chronic hemodialysis patient. 1582 10

Side effects of calcineurin inhibitors (CNIs) include nephrotoxicity and hypertension. Moreover, children have a higher risk of infections and posttransplantation lymphoproliferative disorders. We retrospectively evaluated the efficacy and safety of Sirolimus (SRL) in 18 patients, who were 10.52 +/- 5.03 years at time of transplantation and received a CNI as the core immunosuppression. The most common indications for starting SRL therapy were chronic allograft nephropathy, Epstein-Barr virus-associated neoplasia, and thrombotic microangiopathy. The patients were converted to SRL at 49.14 +/- 45.9 months posttransplantation. Mean follow-up after the switch to SRL was 13.83 +/- 7.24 months. All patients who began SRL therapy remained on that medication. We observed a significant improvement (P < .05) in glomerular filtration rate assessed using the Schwartz formula at 3 months, which was sustained thereafter. There were no changes in proteinuria, plasma lipids, and platelet number. Although the prevalence of hypertensive patients decreased during follow-up, it was not significant. There was one steroid-sensitive, acute rejection episode. Serious adverse events included 1 death due to a relapse of B lymphoma, 1 sepsis, and 1 pancreatic pseudo-cyst. Adverse events were present in 17% of patients: 3 Herpes Simplex infections, and 1 dose-related lymphedema. Further studies are necessary to assess the impact of adverse events in the pediatric transplant population receiving SRL as immunosuppression.
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PMID:Sirolimus in pediatric renal transplantation. 1584

Recurrence of hepatitis C (HepC) has been a most difficult dilemma in liver transplantation (OLT) because the effects of immunosuppression with steroid, mycophenolate mofetil (MMF) calcineurin antagonists, and anti-interleukin-2 antibody as well as the role of preemptive antiviral therapy are uncertain. In this study, we randomized OLT recipients with HepC into two treatment arms: tacrolimus+daclizumab+MMF (study arm) versus tacrolimus+steroids+MMF (control arm). The study arm only received steroids for the treatment of biopsy-proven rejection episodes. Both arms received preemptive anti-viral therapy with Pegasys and ribavirin. The 39 enrolled patients (among 50 to be enrolled) have median follow-up of 458 days with 23 patients (8 in study arm, 15 in control arm) having reached 1 year. The incidences of rejection episodes within 0 to 3 months, 3 to 6 months, and 6 to 12 months were (study vs control): 0% vs 28%; 0% vs 6%; and 13% vs 20%; respectively (P = NS). The 1-year protocol biopsies showed advanced fibrosis (stage 3 or greater) in 20% (3 of 15) of the control arm, but none (0 of 7) of the study arm (P = NS). We compared anticipated side effects of steroids in the first 3 months (study vs control): hypertension (36% vs 58%, P = NS), PTDM (7% vs 43%, P = .02), and wound infections (14% vs 37%, P = NS). In conclusion, liver transplant recipients with HepC tolerate a steroid-free protocol. There was a trend toward reduced steroid side effects and a lower incidence of advanced fibrosis in 1-year biopsy samples among patients receiving the steroid-free protocol.
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PMID:Steroid-free induction and preemptive antiviral therapy for liver transplant recipients with hepatitis C: a preliminary report from a prospective randomized study. 1584 74

There is no controlled clinical trial on the treatment of de novo arterial hypertension after liver transplantation (LT) a common complication using calcineurin inhibitors (CNI) for immunosuppressive therapy. The aim of this study was to compare the efficacy and safety of nifedipine, a calcium channel blocker, and carvedilol, an alpha1- and beta-blocker. The study included 50 patients who developed arterial hypertension after LT. The data on the first 30 patients who have completed 12-month follow-up are reported herein. Eighteen patients received nifedipine, and 12 patients received carvedilol. Patients were evaluated monthly at the outpatient clinic for 1 year. If patients developed severe adverse effects to nifedipine, they were switched to carvedilol and vice versa (therapy failure). The two groups were similar for clinical features, indications for LT, immunosuppressive therapy, and baseline blood pressures. A failure of treatment was observed in 9 of 18 patients treated with nifedipine (50.0%) and one of 12 patients treated with carvedilol (8%, P < .025). Nifedipine was effective in 4 of 18 patients, carvedilol, in 4 of 12 patients (22.21% vs 33.3%, P = NS). Two of the nine nonresponders to nifedipine responded to carvedilol. The efficacy of monotherapy was observed in 11 of 40 randomized patients (27.5%). Carvedilol monotherapy is as effective as nifedipine but far better tolerated.
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PMID:Comparison between nifedipine and carvedilol in the treatment of de novo arterial hypertension after liver transplantation: preliminary results of a controlled clinical trial. 1584 84

The time to failure of a renal allograft is determined by the initial function achieved after transplantation, the number and severity of insults to the graft, and a number of tissue characteristics. The insults a graft usually encounters include ischaemia/reperfusion injury, acute rejection episodes, drug-related nephrotoxicity, hypertension and hyperlipidaemia. Important tissue characteristics include susceptibility to injury and the ability of the tissue to repair damage. Elderly transplant recipients are considered poor immune responders but if a single acute rejection episode occurs this is more likely to significantly shorten graft and patient survival in this age group. Two issues have been identified with the use of old (>50 years of age) donor kidneys. First, compared with kidneys from younger donors, they have an increased incidence of acute interstitial rejection. Secondly, once a rejection episode occurs, the ability to mount a tissue repair process seems impaired. An explanation for the increased loss of grafts from old donors that have experienced acute rejection episodes is that such kidneys have fewer nephrons that function adequately and that the cumulated effect of damage results in an earlier demise of the graft compared with younger donor kidneys. Alternatively, graft parenchymal cells may undergo premature senescence or aging as a result of multiple injuries and repair. If progressive loss of renal mass or senescence is the mechanism responsible for increased graft loss, then it is expected that grafts from older donors will show a progressive decrease in function over time and that the rate of decline of function will correlate with donor age. We have suggested that increased graft loss of older donor kidneys results from increased incidence of acute rejection episodes in the early post-transplantation months together with a partly impaired ability to repair the tissue. Drug pharmacokinetic parameters are generally little influenced by age. However, the degree to which drugs suppress the immune system, and the extent to which kidneys from older donors are susceptible to the nephrotoxic effects of certain drugs, are unpredictable. There appears to be a more delicate balance between adequate immunosuppression and excess nonimmune toxicity in patients receiving older kidneys. Outcome parameters in elderly renal transplant recipients are currently dominated by increased death from infectious disease and drug-related (cardiovascular) causes. Increased susceptibility to nephrotoxic drugs, and to calcineurin inhibitors in particular, may be related to the increased risk of allograft failure experienced by the elderly as a surrogate for chronic allograft nephropathy.
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PMID:The impact of age on rejection in kidney transplantation. 1590 55

A highly selected subject group comprising pediatric recipients of liver (n = 36) and small intestine alone (n = 1) or multivisceral graft (n = 2) were converted to sirolimus maintenance therapy for tacrolimus-related side effects (n = 32) or by primary intent (n = 7). Indications were nephrotoxicity (n = 14), primary intent (n = 7), post-transplant lymphoproliferative disorder (n = 6), seizures (n = 4), recurrent acute rejection (n = 2), and cardiomyopathy (n = 1). Thirty subjects (78%) experienced successful conversion, with one subject requiring atorvastatin for hypercholesterolemia and hypertriglyceridemia. Nine subjects (22%) were converted back to tacrolimus for serious adverse events including acute rejection (n = 2), elevated liver function tests (n = 1), severe leucopenia (n = 1), non-compliance (n = 2), recurrent malignancy/death (n = 1), steatohepatitis (n = 1), and thrombocytopenic thrombotic purpura (n = 1). Among subjects with nephrotoxicity, significant benefit was seen only in those subjects with shorter time to rescue after transplantation (n = 8 of 14 subjects). Additional benefits included a significant decrease in mean serum creatinine from pretransplant values for the entire population, and elimination of antihypertensive treatment in all five subjects receiving it prior to conversion. Hemoglobin, serum cholesterol and triglycerides, white cell counts and platelets remained within normal limits for the duration of follow-up (36 month). Conversion from tacrolimus to sirolimus is successful in selected pediatric liver and intestine recipients. Chronic nephrotoxicity may be ameliorated by early conversion. Improvement in renal function and hypertension management, and absence of sirolimus-related adverse events argue for prospective evaluation of regimens in which mTOR inhibitors are used without calcineurin inhibitors in children.
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PMID:Replacing calcineurin inhibitors with mTOR inhibitors in children. 1591 Mar 98

Cardiovascular morbidity, including coronary artery disease and left ventricular hypertrophy, and mortality are high in patients following renal transplantation. Cardiovascular disease is thought to be due to traditional (hypertension, hyperlipidemia, diabetes mellitus and smoking) as well as nontraditional cardiovascular risk factors (microinflammation). Furthermore, immunosuppressive drugs, namely, calcineurin inhibitors, sirolimus, and steroids, have been reported to adversely affect cardiovascular risk factors (e.g., hypertension, hyperlipidemia, hyperglycemia). Evidence from comparative trials and from conversion studies suggest that blood pressure, hyperlipidemia, and hyperglycemia after renal transplantation may be differentially affected by the calcineurin inhibitors cyclosporine and tacrolimus. In the European Tacrolimus versus Cyclosporin A Microemulsion Renal Transplantation Study, 557 patients were randomly allocated to therapy with tacrolimus (n = 286) versus cyclosporine (n = 271). In addition, to blood pressure, serum cholesterol, HDL cholesterol, triglycerides, and blood glucose, we estimated the 10-year risk of coronary heart disease (Framingham risk score). Tacrolimus resulted in a significantly lower time-weighted average of serum cholesterol (P < .001), and mean arterial blood pressure (P < .05), but a higher time-weighted average of blood glucose (P < .01) than cyclosporine. Mean 10-year coronary artery disease risk estimate was significantly lower in men treated with tacrolimus, (10.0% versus 13.2%; P < .01) but was unchanged in women (4.7% versus 7.0%). Tacrolimus and cyclosporine microemulsion have compound-specific effects on cardiovascular risk factors that differentially affect the predicted rate of coronary artery disease.
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PMID:Cardiovascular risk estimates and risk factors in renal transplant recipients. 1591 88


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