Converting-enzyme inhibitor versus calcium antagonist in cyclosporine-treated renal transplants

The tradeoff between the efficacy of calcineurin inhibitors: prevention of allograft rejection vs. post-transplant renal and cardiovascular complications

Solid organ transplantation has emerged as a crucial intervention in the field of medicine. During transplantation, our human body perceives the organ as an exogenous entity or graft, initiating an immune reaction to eliminate it. This immune response ultimately culminates in the rejection of the graft. So, to mitigate the possibility of graft rejection, implementing immune suppression is imperative. In this context, the utilization of calcineurin inhibitors (CNIs) assumes a pivotal role. Calcineurin inhibitors significantly preserve immunosuppression following solid organ transplantation. Calcineurin inhibitors have considerably improved short-term results in renal transplantation by reducing acute rejection rates. Concerning the limited therapeutic window of these medications, careful monitoring of pharmacological treatment and individual doses is required. However, a significant number of patients do experience CNI toxicity. Side effects of CNIs include renal failure, hypertension, respiratory disorders, gastrointestinal damage, gingivitis, and so on. Higher trough level of the drug causes acute nephrotoxicity, which is of three types: functional toxicity, tubular toxicity, and vascular toxicity. Acute nephrotoxicity, if untreated, leads to irreversible, progressive deterioration of allograft function, leading to chronic nephrotoxicity. Cardiovascular toxicity of CNIs includes atrial hypertension caused by vasoconstriction of the afferent arteriole, vascular remodeling, hypertrophy, dyslipidemia, and also the onset of diabetes. Such clinical complications further affect the patient's survivability and subjective well-being, possibly leading to graft loss. This review focuses on the most severe side effects of CNIs: renal and cardiovascular toxicity.

ACEI/ARB use within one year of kidney transplant is associated with less AKI and graft loss in elderly recipients

BACKGROUND

Optimizing long-term graft survival remains a major focus in transplant. Elderly kidney transplant recipients are vulnerable to acute kidney injury (AKI) and graft loss. This study assessed the safety and efficacy of ACEI/ARB in elderly kidney transplant recipients and impact on graft outcomes.

METHODS

Retrospective, longitudinal, cohort study of 500 patients age ≥60 years, who underwent kidney transplantation between 2005 and 2015. Demographic, transplant, and outcomes data were collected. Manual chart abstraction was conducted to determine medication use at discharge, one, three, and five years post-transplant. Univariate and multivariable Cox regression modeling were used to analyze outcomes.

RESULTS

Mean age of subjects was 66 years (range 60-81). 59% were males and 50% were African-American. 49% had chronic kidney disease (CKD) due to diabetes mellitus (DM). A total of 38, 134, 167, and 112 elderly kidney transplant recipients were on ACEI/ARB at discharge, one, three, and five years post-transplant respectively. ACEI/ARB initiated within one year of transplant was associated with lower risk of graft loss (HR=0.62, CI 0.38-0.99, p = 0.047). This was driven mainly by a lower risk of death (HR=0.41, CI 0.24-0.71, p = 0.002). ACEI/ARB use was associated with lower risk of AKI after 1 year (HR 0.70, CI 0.52-0.95, p = 0.02). ACEI/ARB was not associated with increased risk of acute rejection or hospitalization.

CONCLUSION

Initiation of ACEI/ARB within one year of transplant is associated with lower risk of AKI and graft loss, driven by lower risk of death in elderly kidney transplant recipients. Clinicians should maximize ACEI/ARB therapy early on after kidney transplant.

Antihypertensive treatment for kidney transplant recipients

BACKGROUND

The comparative effects of specific blood pressure (BP) lowering treatments on patient-important outcomes following kidney transplantation are uncertain. Our 2009 Cochrane review found that calcium channel blockers (CCBs) improved graft function and prevented graft loss, while the evidence for other BP-lowering treatments was limited. This is an update of the 2009 Cochrane review.

OBJECTIVES

To compare the benefits and harms of different classes and combinations of antihypertensive drugs in kidney transplant recipients.

SEARCH METHODS

We contacted the Information Specialist and searched the Cochrane Kidney and Transplant Register of Studies up to 3 July 2024 using search terms relevant to this review. Studies in the Register were identified through searches of CENTRAL, MEDLINE, EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs evaluating any BP-lowering agent in recipients of a functioning kidney transplant for at least two weeks were eligible.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed the risks of bias and extracted data. Treatment estimates were summarised using the random-effects model and expressed as relative risk (RR) or mean difference (MD) with 95% confidence intervals (CI). Evidence certainty was assessed using Grades of Recommendation, Assessment, Development and Evaluation (GRADE) processes. The primary outcomes included all-cause death, graft loss, and kidney function.

MAIN RESULTS

Ninety-seven studies (8706 participants) were included. One study evaluated treatment in children. The overall risk of bias was unclear to high across all domains. Compared to placebo or standard care alone, CCBs probably reduce all-cause death (23 studies, 3327 participants: RR 0.83, 95% CI 0.72 to 0.95; I2 = 0%; moderate certainty evidence) and graft loss (24 studies, 3577 participants: RR 0.84, 95% CI 0.75 to 0.95; I2 = 0%; moderate certainty evidence). CCBs may make little or no difference to estimated glomerular filtration rate (eGFR) (11 studies, 2250 participants: MD 1.89 mL/min/1.73 m2, 95% CI -0.70 to 4.48; I2 = 48%; low certainty evidence) and acute rejection (13 studies, 906 participants: RR 10.8, 95% CI 0.85 to 1.35; I2 = 0%; moderate certainty evidence). CCBs may reduce systolic BP (SBP) (3 studies, 329 participants: MD -5.83 mm Hg, 95% CI -10.24 to -1.42; I2 = 13%; low certainty evidence) and diastolic BP (DBP) (3 studies, 329 participants: MD -3.98 mm Hg, 95% CI -5.98 to -1.99; I2 = 0%; low certainty evidence). CCBs have uncertain effects on proteinuria. Compared to placebo or standard care alone, angiotensin-converting-enzyme inhibitors (ACEi) may make little or no difference to all-cause death (7 studies, 702 participants: RR 1.13, 95% CI 0.58 to 2.21; I2 = 0%; low certainty evidence), graft loss (6 studies, 718 participants: RR 0.75, 95% CI 0.49 to 1.13; I2 = 0%; low certainty evidence), eGFR (4 studies, 509 participants: MD -2.46 mL/min/1.73 m2, 95% CI -7.66 to 2.73; I2 = 64%; low certainty evidence) and acute rejection (4 studies, 388 participants: RR 1.75, 95% CI 0.76 to 4.04; I2 = 0%; low certainty evidence). ACEi may reduce proteinuria (5 studies, 441 participants: MD -0.33 g/24 hours, 95% CI -0.64 to -0.01; I2 = 67%; low certainty evidence) but had uncertain effects on SBP and DBP. Compared to placebo or standard care alone, angiotensin receptor blockers (ARB) may make little or no difference to all-cause death (6 studies, 1041 participants: RR 0.69, 95% CI 0.36 to 1.31; I2 = 0%; low certainty evidence), eGRF (5 studies, 300 participants: MD -1.91 mL/min/1.73 m2, 95% CI -6.20 to 2.38; I2 = 57%; low certainty evidence), and acute rejection (4 studies, 323 participants: RR 1.00, 95% CI 0.44 to 2.29; I2 = 0%; low certainty evidence). ARBs may reduce graft loss (6 studies, 892 participants: RR 0.35, 95% CI 0.15 to 0.84; I2 = 0%; low certainty evidence), SBP (10 studies, 1239 participants: MD -3.73 mm Hg, 95% CI -7.02 to -0.44; I2 = 63%; moderate certainty evidence) and DBP (9 studies, 1086 participants: MD -2.75 mm Hg, 95% CI -4.32 to -1.18; I2 = 47%; moderate certainty evidence), but has uncertain effects on proteinuria. The effects of CCBs, ACEi or ARB compared to placebo or standard care alone on cardiovascular outcomes (including fatal or nonfatal myocardial infarction, fatal or nonfatal stroke) or other adverse events were uncertain. The comparative effects of ACEi plus ARB dual therapy, alpha-blockers, and mineralocorticoid receptor antagonists compared to placebo or standard care alone were rarely evaluated. Head-to-head comparisons of ACEi, ARB or thiazide versus CCB, ACEi versus ARB, CCB or ACEi versus alpha- or beta-blockers, or ACEi plus CCB dual therapy versus ACEi or CCB monotherapy were scarce. No studies reported outcome data for cancer or life participation.

AUTHORS' CONCLUSIONS

For kidney transplant recipients, the use of CCB therapy to reduce BP probably reduces death and graft loss compared to placebo or standard care alone, while ARB may reduce graft loss. The effects of ACEi and ARB compared to placebo or standard care on other patient-centred outcomes were uncertain. The effects of dual therapy, alpha-blockers, and mineralocorticoid receptor antagonists compared to placebo or standard care alone and the comparative effects of different treatments were uncertain.

New onset hypertension after transplantation

It has been reported that up to 90% of organ transplant recipients have suboptimal blood pressure control. Uncontrolled hypertension is a well-known culprit of cardiovascular and overall morbidity and mortality. In addition, rigorous control of hypertension after organ transplantation is a crucial factor in prolonging graft survival. Nevertheless, hypertension after organ transplantation encompasses a broader range of causes than those identified in non-organ transplant patients. Hence, specific management awareness of those factors is mandated. An in-depth understanding of hypertension after organ transplantation remains a debatable issue that necessitates further clarification. This article provides a comprehensive review of the prevalence, risk factors, etiology, complications, prevention, and management of hypertension after organ transplantation.

The Many Faces of Calcineurin Inhibitor Toxicity-What the FK?

Calcineurin inhibitors (CNIs) are both the savior and Achilles' heel of kidney transplantation. Although CNIs have significantly reduced rates of acute rejection, their numerous toxicities can plague kidney transplant recipients. By 10 years, virtually all allografts will have evidence of CNI nephrotoxicity. CNIs have been strongly associated with hypertension, dyslipidemia, and new onset of diabetes after transplantation-significantly contributing to cardiovascular risk in the kidney transplant recipient. Multiple electrolyte derangements including hyperkalemia, hypomagnesemia, hypercalciuria, metabolic acidosis, and hyperuricemia may be challenging to manage for the clinician. Finally, CNI-associated tremor, gingival hyperplasia, and defects in hair growth can have a significant impact on the transplant recipient's quality of life. In this review, the authors briefly discuss the pharmacokinetics of CNI and discuss the numerous clinically relevant toxicities of commonly used CNIs, cyclosporine and tacrolimus.

Comparative effectiveness of different antihypertensive agents in kidney transplantation: a systematic review and meta-analysis

Background

We conducted a systematic review and meta-analysis to compare benefits and harms of different antihypertensive drug classes in kidney transplant recipients, as post-transplant hypertension (HTN) associates with increased cardiovascular (CV) morbidity and mortality.

Methods

The Ovid-MEDLINE, PubMed and CENTRAL databases were searched for randomized controlled trials (RCTs) comparing all main antihypertensive agents versus placebo/no treatment, routine treatment.

Results

The search identified 71 RCTs. Calcium channel blockers (CCBs) (26 trials) reduced the risk for graft loss {risk ratio [RR] 0.58 [95% confidence interval (CI) 0.38–0.89]}, increased glomerular filtration rate (GFR) [mean difference (MD) 3.08 mL/min (95% CI 0.38–5.78)] and reduced blood pressure (BP). Angiotensin-converting enzyme inhibitors (ACEIs) (13 trials) reduced the risk for graft loss [RR 0.62 (95% CI 0.40–0.96)] but decreased renal function and increased the risk for hyperkalaemia. Angiotensin receptor blockers (ARBs) (10 trials) did not modify the risk of death, graft loss and non-fatal CV events and increased the risk for hyperkalaemia. When pooling ACEI and ARB data, the risk for graft failure was lower in renin–angiotensin system (RAS) blockade as compared with control treatments. In direct comparison with ACEIs or ARBs (11 trials), CCBs increased GFR [MD 11.07 mL/min (95% CI 6.04–16.09)] and reduced potassium levels but were not more effective in reducing BP. There are few available data on mortality, graft loss and rejection. Very few studies performed comparisons with other active drugs.

Conclusions

CCBs could be the preferred first-step antihypertensive agents in kidney transplant patients, as they improve graft function and reduce graft loss. No definite patient or graft survival benefits were associated with RAS inhibitor use over conventional treatment.

Molecular basis of the counteraction by calcium channel blockers of cyclosporine nephrotoxicity

Nephrotoxicity is a serious side effect for the immunosuppressant drug cyclosporine A(CSA). In this study, we tested the hypothesis that administration of calcium channel blockers such as verapamil or nifedipine ameliorates renal CSA-induced renal dysfunction. Furthermore, our study investigates the roles of inflammatory, oxidative, and fibrotic pathways in CSA-induced renal dysfunction. Six groups of male rats ( n = 6/group) were used and received one of the following treatments for seven consecutive days: vehicle (Cremophor EL ip), CSA (25 mg·kg^-1·day^-1 ip), verapamil (2 mg·kg^-1·day^-1 ip), nifedipine (3 mg·kg^-1·day^-1 ip), CSA in the presence or absence of either verapamil, or nifedipine. Biochemical and histomorphometric analyses showed that rats treated with CSA exhibited clear signs of nephrotoxicity that included 1) proteinuria and elevations in serum creatinine and blood urea nitrogen, 2) mesangial expansion, 3) increases in glomerular and tubular type IV collagen expression, and 4) increases in the glomerulosclerosis and tubulointerstitial fibrosis indices. Although the single administration of nifedipine or verapamil had no significant effect on renal pathology, or its biochemical and physiological function, the concurrent use of either calcium channel blockers significantly and equipotently ameliorated the biochemical, morphological, and functional derangements caused by CSA. More importantly, we report that the oxidative (reactive oxygen species production, NADPH-oxidase activity, and dual oxidase 1/2 levels), fibrotic (transforming growth factor-β1 expression), and inflammatory (NF-κB expression) manifestations of renal toxicity induced by CSA were significantly reversed upon administration of nifedipine or verapamil. Together, these results highlight the efficacy of calcium channel-blocking agents in attenuating CSA-induced nephrotoxicity and predisposing biochemical and molecular machineries.

Protecting the Kidney in Liver Transplant Recipients: Practice-Based Recommendations From the American Society of Transplantation Liver and Intestine Community of Practice

Both acute and chronic kidney disease are common after liver transplantation and result in significant morbidity and mortality. The introduction of the Model for End-stage Liver Disease score has directly correlated with an increased prevalence of perioperative renal dysfunction and the number of simultaneous liver-kidney transplantations performed. Kidney dysfunction in this population is typically multifactorial and related to preexisting conditions, pretransplantation renal injury, perioperative events, and posttransplantation nephrotoxic immunosuppressive therapies. The management of kidney disease after liver transplantation is challenging, as by the time the serum creatinine level is significantly elevated, few interventions affect the course of progression. Also, immunological factors such as antibody-mediated kidney rejection have become of greater interest given the rising liver-kidney transplant population. Therefore, this review, assembled by experts in the field and endorsed by the American Society of Transplantation Liver and Intestine Community of Practice, provides a critical assessment of measures of renal function and interventions aimed at preserving renal function early and late after liver and simultaneous liver-kidney transplantation. Key points and practice-based recommendations for the prevention and management of kidney injury in this population are provided to offer guidance for clinicians and identify gaps in knowledge for future investigations.

Hypertension induced by chemotherapeutic and immunosuppresive agents: a new challenge

BACKGROUND

Hypertension is a common adverse effect of certain anti neoplastic therapy. The incidence and severity of hypertension are dependent mainly on the type and the dose of the drug.

METHODS

We reviewed the literature for studies that reported the effect of anti neoplastic agents on blood pressure in patients with malignancies. The medical databases of PubMed, MEDLINE and EMBASE were searched for articles published in English between 1955 and June 2012. The effects of specific agents on blood pressure were analyzed.

RESULTS AND CONCLUSIONS

Hypertension is a prevalent adverse effect of many of the new chemotherapy agents such as VEGF inhibitors. Approximately 30% of patients treated for cancer will have concomitant hypertension, and crucial chemotherapy can sometimes be stopped due to new onset or worsening severe hypertension. The importance of a timely diagnosis and optimal management of HTN in this group of patients is related to the facts that HTN is a well established risk factor for chemotherapy-induced cardiotoxicity and if left untreated, can alter cancer management and result in dose reductions or termination of anti-cancer treatments as well as life-threatening end organ damage.

Cardiovascular morbidity and mortality after kidney transplantation

Kidney transplantation is the optimal treatment for patients with end stage renal disease (ESRD) who would otherwise require dialysis. Patients with ESRD are at dramatically increased cardiovascular (CV) risk compared with the general population. As well as improving quality of life, successful transplantation accords major benefits by reducing CV risk in these patients. Worldwide, cardiovascular disease remains the leading cause of death with a functioning graft and therefore is a leading cause of graft failure. This review focuses on the mechanisms underpinning excess CV morbidity and mortality and current evidence for improving CV risk in kidney transplant recipients. Conventional CV risk factors such as hypertension, diabetes mellitus, dyslipidaemia and pre-existing ischaemic heart disease are all highly prevalent in this group. In addition, kidney transplant recipients exhibit a number of risk factors associated with pre-existing renal disease. Furthermore, complications specific to transplantation may ensue including reduced graft function, side effects of immunosuppression and post-transplantation diabetes mellitus. Strategies to improve CV outcomes post-transplantation may include pharmacological intervention including lipid-lowering or antihypertensive therapy, optimization of graft function, lifestyle intervention and personalizing immunosuppression to the individual patients risk profile.

Renal sodium transporters are increased in urinary exosomes of cyclosporine-treated kidney transplant patients

BACKGROUND/AIMS

Cyclosporine (CsA) is a calcineurin inhibitor widely used as an immunosuppressant in organ transplantation. Previous studies demonstrated the relationship between CsA and renal sodium transporters such as the Na-K-2Cl cotransporter in the loop of Henle (NKCC2). Experimental models of CsA-induced hypertension have shown an increase in renal NKCC2.

METHODS

Using immunoblotting of urinary exosomes, we investigated in CsA-treated kidney transplant patients (n = 39) the excretion of NKCC2 and Na-Cl cotransporter (NCC) and its association with blood pressure (BP) level. We included 8 non-CsA-treated kidney transplant patients as a control group. Clinical data, immunosuppression and hypertension treatments, blood and 24-hour urine tests, and 24-hour ambulatory BP monitoring were recorded.

RESULTS

CsA-treated patients tended to excrete a higher amount of NKCC2 than non-CsA-treated patients (mean ± SD, 175 ± 98 DU and 90 ± 70.3 DU, respectively; p = 0.05) and showed higher BP values (24-hour systolic BP 138 ± 17 mm Hg and 112 ± 12 mm Hg, p = 0.003; 24-hour diastolic BP, 83.8 ± 9.8 mm Hg and 72.4 ± 5.2 mm Hg, p = 0.015, respectively). Within the CsA-treated group, there was no correlation between either NKCC2 or NCC excretion and BP levels. This was confirmed by a further analysis including potential confounding factors. On the other hand, a significant positive correlation was observed between CsA blood levels and the excretion of NKCC2 and NCC.

CONCLUSION

Overall, these results support the hypothesis that CsA induces an increase in NKCC2 and NCC in urinary exosomes of renal transplant patients. The fact that the increase in sodium transporters in urine did not correlate with the BP level suggests that in kidney transplant patients, other mechanisms could be implicated in CsA-induced hypertension.

Hypertension: The Neglected Complication of Transplantation

Arterial hypertension and transplantation are closely linked, and its association may promote impaired graft and overall survival. Since the introduction of calcineurin inhibitors, it is observed in 50–80% of transplanted patients. However, many pathophysiological mechanisms are involved in its genesis. In this review, we intend to provide an updated overview of these mechanisms, dealing with the causes common to all kinds of transplantation and emphasizing special cases with distinct features, and to give a perspective on the pharmacological approach, in order to help clinicians in the management of this frequent complication.

Hypertension in kidney transplant recipients

Arterial hypertension is frequently observed in renal transplant recipients. Its pathogenesis is multifactorial in most cases. Calcineurin inhibitors (CNI) can increase peripheral vascular resistance by inducing arteriolar vasoconstriction and can cause extracellular fluid expansion by reducing the glomerular filtration rate (GFR), activating the renin-angiotensin system (RAS), and by inactivating the atrial natriuretic peptide. Glucocorticoids can impair urinary water and salt excretion. Poor graft function can lead to increased extracellular volume and inappropriate production of renin. Native kidneys, older age of the donor and transplant renal artery stenosis (TRAS) may also contribute to the development of hypertension. Arterial hypertension not only can increases the risk for cardiovascular events but can also deteriorate renal allograft function. A number of studies have shown that the higher the levels of blood pressure are, the higher is the risk of graft failure. On the other hand, a good control of blood pressure may prevent many cardiovascular and renal complications. Appropriate lifestyle modification is the first step for treating hypertension. Calcium channel blockers (CCB) and renin-angiotensin system (RAS) inhibitors are the most frequently used antihypertensive agents, but in many cases, a combination of these and other drugs is required to obtain good control of hypertension.

Hypertension after kidney transplant

Hypertension in kidney transplant recipients is a major "traditional" risk factor for atherosclerotic cardiovascular disease. Importantly, atherosclerotic cardiovascular disease is the leading cause of premature death and a major factor in death-censored graft failure in transplant recipients. The blood pressure achieved after transplant is related inversely to postoperative glomerular filtration rate (GFR), with many patients experiencing a significant improvement in blood pressure control with fewer medications within months of surgery. However, the benefits of improved GFR and fluid status may be affected by the immunosuppression regimen. Immunosuppressive agents affect hypertension through a variety of mechanisms, including catechol- and endothelin-induced vasoconstriction, abrogation of nitric oxide-induced vasodilatation, and sodium retention. Most notable is the role of calcineurin inhibitors in promoting hypertension, cyclosporine more so than tacrolimus. Additionally, the combination of calcineurin- and mammalian target of rapamycin (mTOR)-inhibitor therapy is synergistically nephrotoxic and promotes hypertension, whereas steroid withdrawal and minimization strategies seem to have little or no impact on hypertension. Other important causes of hypertension after transplant, beyond a progressive decrease in GFR, include transplant renal artery stenosis and sequelae of antibody-mediated rejection. Calcium channel blockers may be the most useful medication for mitigating calcineurin inhibitor-induced vasoconstriction, and use of such agents may be associated with improvements in GFR. Use of inhibitors of the renin-angiotensin system, such as angiotensin-converting enzyme inhibitors and angiotensin receptor blockers, remains an attractive strategy for many transplant recipients, although some recipients may have significant adverse effects associated with these medications, including decreased GFR, hyperkalemia, and anemia. In conclusion, hypertension control affects both patient and long-term transplant survival, and its best management requires careful analysis of causes and close monitoring of therapies.

Primary care of the transplant patient

A total of 153,245 patients are living with a solid organ transplant in the US. In addition, patients are experiencing high 5-year survival rates after transplantation. Thus, primary care physicians will be caring for transplanted patients. The aim of this review is to update primary care physicians on chronic diseases, screening for malignancy, immunizations, and contraception in the transplant patient. Several studies on the treatment of hypertension and hyperlipidemia demonstrate that most agents used to treat the general population also can be used to treat transplant recipients. Little information exists on the medical management of diabetes in the transplant population, but experts in the area believe that the treatment of diabetes should be similar. Transplant recipients are at increased risk for all malignancies. Aggressive screening should be employed for all cancers with a proven screening benefit. Killed immunizations are safe for the transplant population, but live virus vaccines should be avoided. Women of childbearing age should be counseled about the impact of immunosuppressants on the efficacy and side effects of contraception.

Early high pulse pressure is associated with graft dysfunction and predicts poor kidney allograft survival

BACKGROUND

Pulse pressure (PP), which reflects the pulsatile component of the blood pressure (BP), is known as a major predictor of cardiovascular events and death. In the elderly and type 2 diabetic patients, PP is associated with low glomerular filtration rate and albuminuria. Because kidney allograft survival is closely related to BP levels, we investigated the impact of early high PP, systolic, diastolic, and mean arterial BP on kidney allograft survival.

METHODS

Renal hemodynamic and function studies using isotopic methods were prospectively performed in 493 renal transplant patients at 3 months posttransplantation to determine the impact of the different BP components on allograft survival using a proportional hazard model.

RESULTS

After a median follow-up of 6.3 years, 91 allografts were lost. High PP was associated with high systolic, diastolic, and mean arterial pressure, heart rate, recipient age, glycemia, and low glomerular filtration rate. Moreover, PP emerged as the strongest BP component influencing overall and death-censored kidney allograft survival.

CONCLUSION

High PP is an early marker of poor allograft outcome that could be corrected by therapeutic intervention.

Antihypertensives for kidney transplant recipients: systematic review and meta-analysis of randomized controlled trials

In nontransplant populations, effects of different antihypertensive drug classes vary. Relative effects in kidney transplant recipients are uncertain. We performed a systematic review including random effects meta-analysis of randomized controlled trials, using Cochrane Collaboration methodology. We identified 60 trials, enrolling 3802 recipients. Twenty-nine trials (2262 patients) compared calcium channel blockers (CCB) with placebo or no treatment, 10 trials (445 patients) compared angiotensin-converting enzyme inhibitors (ACEi) with placebo or no treatment, and seven studies (405 patients) compared CCB with ACEi. CCB compared with placebo or no treatment (plus additional agents in either arm as required) reduced graft loss (risk ratio [RR] 0.75, 95% confidence intervals [CI] 0.57-0.99) and improved glomerular filtration rate (GFR; mean difference [MD] 4.5 mL/min, 95% CI 2.2-6.7). Data on ACEi versus placebo or no treatment were inconclusive for GFR (MD -8.1 mL/min, 95% CI -18.6-2.4) and inconsistent for graft loss, precluding meta-analysis. In direct comparison with CCB, ACEi decreased GFR (MD 11.5 mL/min, 95% CI 7.2-15.8), proteinuria (MD 0.28 g/day, 95% CI 0.10-0.47), hemoglobin (MD 11.5 g/L, 95% CI 7.2-15.8), and increased hyperkalemia (RR 3.7, 95% CI 1.9-7.7). Graft loss data were inconclusive (RR 7.4, 95% CI 0.4-140). These data suggest that CCB may be preferred as first-line agents for hypertensive kidney transplant recipients.

Antihypertensive treatment for kidney transplant recipients

BACKGROUND

In some nontransplant populations, effects of different antihypertensive drug classes vary. Relative effects in kidney transplant recipients are uncertain.

OBJECTIVES

To assess comparative effects of different classes of antihypertensive agents in kidney transplant recipients.

SEARCH STRATEGY

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, conference proceedings and reference lists of identified studies were searched.

SELECTION CRITERIA

Randomised controlled trials of any antihypertensive agent applied to kidney transplant recipients for at least two weeks were included.

DATA COLLECTION AND ANALYSIS

Data was extracted by two investigators independently. Study quality, transplant outcomes and other patient centred outcomes were assessed using random effects meta-analysis. Risk ratios (RR) for dichotomous outcomes and mean difference (MD) for continuous outcomes, both with 95% confidence intervals (CI) were calculated. Stratified analyses and meta-regression were used to investigate heterogeneity.

MAIN RESULTS

We identified 60 studies, enrolling 3802 recipients. Twenty-nine studies (2262 participants) compared calcium channel blockers (CCB) to placebo/no treatment, 10 studies (445 participants) compared angiotensin converting enzyme inhibitors (ACEi) to placebo/no treatment and seven studies (405 participants) compared CCB to ACEi. CCB compared to placebo/no treatment (plus additional agents in either arm as required) reduced graft loss (RR 0.75, 95% CI 0.57 to 0.99) and improved glomerular filtration rate (GFR), (MD, 4.45 mL/min, 95% CI 2.22 to 6.68). Data on ACEi versus placebo/no treatment were inconclusive for GFR (MD -8.07 mL/min, 95% CI -18.57 to 2.43), and variable for graft loss, precluding meta-analysis. In direct comparison with CCB, ACEi decreased GFR (MD -11.48 mL/min, 95% CI -5.75 to -7.21), proteinuria (MD -0.28 g/24 h, 95% CI -0.47 to -0.10), haemoglobin (MD -12.96 g/L, 95% CI -5.72 to -10.21) and increased hyperkalaemia (RR 3.74, 95% CI 1.89 to 7.43). Graft loss data were inconclusive (RR 7.37, 95% CI 0.39 to 140.35). Other drug comparisons were compared in small numbers of participants and studies.

AUTHORS' CONCLUSIONS

These data suggest that CCB may be preferred as first line agents for hypertensive kidney transplant recipients. ACEi have some detrimental effects in kidney transplant recipients. More high quality studies reporting patient centred outcomes are required.

Calcineurin inhibitor nephrotoxicity

The use of the calcineurin inhibitors cyclosporine and tacrolimus led to major advances in the field of transplantation, with excellent short-term outcome. However, the chronic nephrotoxicity of these drugs is the Achilles' heel of current immunosuppressive regimens. In this review, the authors summarize the clinical features and histologic appearance of both acute and chronic calcineurin inhibitor nephrotoxicity in renal and nonrenal transplantation, together with the pitfalls in its diagnosis. The authors also review the available literature on the physiologic and molecular mechanisms underlying acute and chronic calcineurin inhibitor nephrotoxicity, and demonstrate that its development is related to both reversible alterations and irreversible damage to all compartments of the kidneys, including glomeruli, arterioles, and tubulo-interstitium. The main question--whether nephrotoxicity is secondary to the actions of cyclosporine and tacrolimus on the calcineurin-NFAT pathway--remains largely unanswered. The authors critically review the current evidence relating systemic blood levels of cyclosporine and tacrolimus to calcineurin inhibitor nephrotoxicity, and summarize the data suggesting that local exposure to cyclosporine or tacrolimus could be more important than systemic exposure. Finally, other local susceptibility factors for calcineurin inhibitor nephrotoxicity are reviewed, including variability in P-glycoprotein and CYP3A4/5 expression or activity, older kidney age, salt depletion, the use of nonsteroidal anti-inflammatory drugs, and genetic polymorphisms in genes like TGF-beta and ACE. Better insight into the mechanisms underlying calcineurin inhibitor nephrotoxicity might pave the way toward more targeted therapy or prevention of calcineurin inhibitor nephrotoxicity.

Late kidney allograft loss: what we know about it, and what we can do about it

Despite dramatic improvements in immunosuppression, late graft loss after kidney transplantation remains a common and difficult problem. Histologic evaluation may reveal changes related to BK polyomavirus infection, hypertension, or calcineurin inhibitor toxicity, which can help to guide therapy. The designation chronic allograft nephropathy should thus be reserved for biopsies with tubular atrophy and interstitial fibrosis without an apparent cause. Although the cause clearly includes both antigen-dependent and antigen-independent events, the approach remains largely to exclude immune mechanisms. Although this review discusses the potential contribution of antibody to chronic injury, it focuses on the basic elements of kidney injury, the role of parenchymal cells in promoting injury, and the proliferative and inflammatory responses that accompanying injury. Strategies to manage these recipients include close attention to accompanying hypertension, diabetes, and hyperlipidemia, as well as consideration for altering immunosuppression; however, therapies that limit epithelial-to-mesenchymal transition or directly block fibrosis pathways may reduce chronic allograft fibrosis and may prove to be useful. Understanding the basic pathogenesis sufficiently to allow early intervention may finally benefit patients who are at high risk for tubular atrophy and interstitial fibrosis and promote their long-term graft function.

Renin angiotensin system blockade in kidney transplantation: a systematic review of the evidence

ACE-inhibitors and angiotensin receptor blockers (ARB) slow the progression of renal disease in non-transplant patients. A systematic review of randomized trials (n = 21 trials with 1549 patients) was conducted to determine the effect of ACE-inhibitor or ARB use following kidney transplantation. With a median follow-up of 27 months, ACE-inhibitor or ARB use was associated with a significant decrease in glomerular filtration rate (-5.8 mL/min; 95% CI -10.6 to -0.99). ACE-inhibitor or ARB use resulted in a lower hematocrit (-3.5%; 95% CI -6.1 to -0.95), reduction in proteinuria (-0.47 gm/d; 95% CI -0.86 to -0.08) but no change in the serum potassium (0.18 mmol/L; 95% CI -0.03 to 0.40). ACE-inhibitor or ARB use results in clinically important reductions in proteinuria, hematocrit and glomerular filtration rate in renal transplant recipients, but there are insufficient data to determine the effect on patient or graft survival. Randomized trials of sufficient power and duration that examine these hard outcomes should be conducted. Until such trials are completed, this study provides quantitative estimates of the risks and benefits of ACE-inhibitor or ARB use that can be used by clinicians considering prescribing these medications to kidney transplant recipients or to researchers designing future trials.

Hypertension After Renal Transplant

Hypertension is common after renal transplant and is associated with adverse graft and patient outcomes. A thorough understanding of the unique factors that operate in renal transplant recipients is essential for the proper evaluation and management of this disorder. In this review, the authors outline the pathogenesis, diagnostic workup, and treatment of hypertension after renal transplant.

Reducing the risks of cardiovascular disease in liver allograft recipients

Liver allograft recipients are at increased risk of death from cerebrovascular and cardiovascular disease. We propose the following strategy of risk-reduction, based on currently available literature. Lifestyle: standard advice should be given (avoidance of smoking, excess alcohol and obesity, adequate exercise, reduction of excess sodium intake). Hypertension: target blood pressure should be 140/90 mmHg or lower, but for those with diabetes or renal disease, 130/80 mmHg or lower. For patients without proteinuria, antihypertensive therapy should be initiated with a calcium channel blocker and for those with proteinuria, an angiotensin-converting enzyme (ACE) inhibitor or angiotensin II receptor blocker. If monotherapy fails to achieve adequate response, calcium channel blockers and ACE-inhibitors or angiotensin II receptor blockers should be combined. If hypertension remains uncontrolled, an alpha-blocker may be added. Consideration should be given to changing immunosuppression and avoiding use of calcineurin inhibitors. Diabetes: recipients should be regularly screened for diabetes. For patients with new-onset diabetes after transplant, stepwise therapy should be guided by HbA1c concentrations, as with type II diabetes mellitus. Hyperlipidemia: annual screening of lipid profile should be undertaken, with treatment thresholds and targets based on those advocated for the high risk general population. Dietary intervention is appropriate for all patients. A statin should be considered as the first line treatment to achieve specified targets. In patients receiving a calcineurin inhibitor, Pravastatin should be commenced at a dose of 10 mg/day. In patients receiving other forms of immunosuppression, pravastatin may be commenced at a dose of 20 mg/day. Liver tests should be monitored and patients warned to report myalgia. If monotherapy is inadequate, ezetimibe or a fibrate may be added. Consideration may be given to change in immunosuppression if combination lipid-lowering therapy proves inadequate.

Improved long-term outcomes after renal transplantation associated with blood pressure control

Hypertension has a negative impact on long-term outcomes after renal transplantation. We investigated the effect of a recent decline in blood pressure among renal transplant patients in the Collaborative Transplant Study (CTS) database on long-term graft and patient survival. CTS data were used to evaluate transplant outcomes in relation to recipient systolic blood pressure (SBP) for 24,404 first cadaver kidney recipients transplanted between 1987 and 2000. Patients whose SBP was > 140 mmHg at 1 year posttransplantation but controlled to < or = 140 mmHg by 3 years had significantly improved long-term graft outcome compared with patients with sustained high SBP to 3 years (RR 0.79; CI 0.73-0.86; p < 0.001). Additional examination at 5 years showed that SBP lowering after year 3 was associated with improved 10-year graft survival (RR 0.83; CI 0.72-0.96; p = 0.01), whereas even a temporary increase in SBP at 3 years was associated with worse survival (RR 1.37; CI 1.19-1.58; p < 0.001). Changes in SBP were paralleled by changes in the incidence of cardiovascular death among recipients younger than 50 but not in older recipients. Lowering SBP, even after several years of posttransplantation hypertension, is associated with improved graft and patient survival in renal allograft recipients.

Calcium channel blockade and preservation of renal graft function in cyclosporine-treated recipients: a prospective randomized placebo-controlled 2-year study

BACKGROUND

Studies have provided conflicting results as to the protective role of calcium channel blockers (CCB) in cyclosporine-treated patients with regard to blood pressure control and preservation of renal graft function. Lacidipine is a dihydropyridine CCB that possesses antioxidative, anti-atherosclerotic, and anti-adhesion properties and was shown to prevent cyclosporine-induced nephrotoxicity in a rat model.

METHODS

We conducted a multicenter prospective, randomized, placebo-controlled study in 131 de novo recipients of a cadaveric renal allograft on cyclosporine therapy. The aim of this 2-year study was to assess the effects of lacidipine on graft function (plasma iohexol clearance), renal plasma flow, anastomotic arterial blood flow, deterioration of renal function, blood pressure, acute rejection, and hospitalization rate.

RESULTS

A total of 118 recipients were available for intention-to-treat analysis on efficacy (lacidipine: n=59; placebo: n=59). Graft function assessed by serum creatinine concentration and glomerular filtration rate measured as plasma iohexol clearance, was persistently better in lacidipine-treated patients from 1 year onwards (respectively, P<0.01 and P<0.05). Renal plasma flow and anastomotic blood flow were not significantly higher in lacidipine-treated patients. Three patients on lacidipine therapy and four on placebo experienced treatment failure defined as an increase in serum creatinine from baseline of more than 60% (log-rank test: P=0.57). Study groups did not differ in acute rejection rate, trough blood cyclosporine concentrations, blood pressure, number of antihypertensive drugs, hospitalization rate, and adverse event rate.

CONCLUSIONS

The use of calcium channel blockers in cyclosporine-treated renal recipients results in a significantly better allograft function at 2 years and this effect is independent of blood pressure lowering.

Renoprotective effect of Hemidesmus indicus, a herbal drug used in gentamicin-induced renal toxicity

BACKGROUND AND AIMS

Owing to the global trend towards improved 'quality of life', there is considerable evidence of an increase in demand for medicinal plants. The WHO guidelines define basic criteria for the standardization of herbal medicines. The present work is an effort in this direction to prove the safety and efficacy of Hemidesmus indicus Linn. in the management of nephrotoxicity induced by aminoglycosides such as gentamicin.

METHODS AND RESULTS

Simple, quality control methods using high performance thin layer chromatographic (HPTLC) phytochemical fingerprint, proximate analysis, and the stability of the H. indicus root powder were developed. From the toxicity study using albino Swiss mice, it was observed that the drug (H. indicus) was relatively safe up to 7 g/kg bodyweight dose. Efficacy was evaluated against gentamicin-induced nephrotoxicity in albino Wister rats. The study examined animals from the following groups: no treatment, gentamicin treated, gentamicin treated recovery, and gentamicin and plant treated. Animals from all groups were killed on day 13 of the study; those from gentamicin treated group were killed on the seventh day. Assessment of the drug efficacy drug was conducted by using haematological and histological examination.

CONCLUSION

The treatment with H. indicus helped in the management of renal impairment, which was induced by gentamicin in rats. This is evident from the results obtained for various kidney function tests for gentamicin, along with the results from the plant treated group, and is in comparison with the results found for the gentamicin recovery group. A histological examination of kidneys also supports the findings from haematological evaluations. The plant shows promise as an adjunct therapy along side aminoglycosides as it reduces nephrotoxicity caused by aminoglycosides.

Clinical practice guidelines for managing dyslipidemias in kidney transplant patients: a report from the Managing Dyslipidemias in Chronic Kidney Disease Work Group of the National Kidney Foundation Kidney Disease Outcomes Quality Initiative

The incidence of cardiovascular disease (CVD) is very high in patients with chronic kidney (CKD) disease and in kidney transplant recipients. Indeed, available evidence for these patients suggests that the 10-year cumulative risk of coronary heart disease is at least 20%, or roughly equivalent to the risk seen in patients with previous CVD. Recently, the National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (K/DOQI) published guidelines for the diagnosis and treatment of dyslipidemias in patients with CKD, including transplant patients. It was the conclusion of this Work Group that the National Cholesterol Education Program Guidelines are generally applicable to patients with CKD, but that there are significant differences in the approach and treatment of dyslipidemias in patients with CKD compared with the general population. In the present document we present the guidelines generated by this workgroup as they apply to kidney transplant recipients. Evidence from the general population indicates that treatment of dyslipidemias reduces CVD, and evidence in kidney transplant patients suggests that judicious treatment can be safe and effective in improving dyslipidemias. Dyslipidemias are very common in CKD and in transplant patients. However, until recently there have been no adequately powered, randomized, controlled trials examining the effects of dyslipidemia treatment on CVD in patients with CKD. Since completion of the K/DOQI guidelines on dyslipidemia in CKD, the results of the Assessment of Lescol in Renal Transplantation (ALERT) Study have been presented and published. Based on information from randomized trials conducted in the general population and the single study conducted in kidney transplant patients, these guidelines, which are a modified version of the K/DOQI dyslipidemia guidelines, were developed to aid clinicians in the management of dyslipidemias in kidney transplant patients. These guidelines are divided into four sections. The first section (Introduction) provides the rationale for the guidelines, and describes the target population, scope, intended users, and methods. The second section presents guidelines on the assessment of dyslipidemias (guidelines 1-3), while the third section offers guidelines for the treatment of dyslipidemias (guidelines 4-5). The key guideline statements are supported mainly by data from studies in the general population, but there is an urgent need for additional studies in CKD and in transplant patients. Therefore, the last section outlines recommendations for research.

Calcium channel blockers as the treatment of choice for hypertension in renal transplant recipients: fact or fiction

Posttransplantation hypertension has been identified as an independent risk factor for chronic allograft dysfunction and loss. Based on available morbidity and mortality data, posttransplantation hypertension must be identified and managed appropriately. During the past decade, calcium channel blockers have been recommended by some as the antihypertensive agents of choice in this population, because it was theorized that their vasodilatory effects would counteract the vasoconstrictive effects of the calcineurin inhibitors. With increasing data becoming available, reexamining the use of traditional antihypertensive agents, including diuretics and beta-blockers, or the newer agents, angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers, may be beneficial. Transplant clinicians must choose antihypertensive agents that will provide their patients with maximum benefit, from both a renal and a cardiovascular perspective. Beta-blockers, diuretics, and ACE inhibitors have all demonstrated significant benefit on morbidity and mortality in patients with cardiovascular disease. Calcium channel blockers have been shown to possess the ability to counteract cyclosporine-induced nephrotoxicity. When compared with beta-blockers, diuretics, and ACE inhibitors, however, the relative risk of cardiovascular events is increased with calcium channel blockers. With the long-term benefits of calcium channel blockers on the kidney unknown and a negative cardiovascular profile, these agents are best reserved as adjunctive therapy to beta-blockers, diuretics, and ACE inhibitors.

Outcomes in kidney transplantation

It is estimated that there are greater than 100000 kidney transplant recipients with a functioning graft in the United States. Recent advances in immunosuppression have improved short-term graft survival rates and decreased early mortality by decreasing the incidence and therapy for acute rejection episodes. For those accepted on the waiting list, transplant prolongs patient survival compared with remaining on dialysis. During the 1990s, 3 new immunosuppressive drugs were introduced in clinical kidney transplantation. All were approved for use by the Food and Drug Administration after large, controlled, randomized trials. Mycophenolate mofetil (MMF), when combined with cyclosporine (CSA) and prednisone, lowered acute rejection rates by nearly 50% compared with control. Tacrolimus compared with CSA also significantly reduced acute rejection rates in kidney transplant recipients, but was associated with a significant increase in posttransplant diabetes mellitus (PTDM) in the early trials. When evaluated in combination with MMF, the incidence of PTDM was much lower. At the end of the decade, sirolimus was shown in several randomized trials to lower acute rejection rates and is believed to be less nephrotoxic compared with calcineurin inhibitors. All of the randomized trials were not statistically powered to assess long-term superiority. Registry analyses have been performed that appear to show some long-term benefit of immunosuppressive therapy with MMF. Other outcome assessments in kidney transplant recipients include risk factors for chronic allograft nephropathy, hypertension, hyperlipidemia, and bone disease. Although there are few randomized trials, understanding of the significance of these common complications has progressed and strategies for therapy and intervention have been developed. This article focuses on the randomized trials of immunosuppressive therapy and complications associated with use of these drugs. In addition, we review the current management and intervention for the comorbidities associated with the long-term clinical management of the kidney transplant recipient.

Treatment of hypertension in renal transplant recipients

PURPOSE OF REVIEW

Hypertension is very common in renal transplant recipients and is a significant risk factor for mortality from cardiovascular diseases and for development of graft dysfunction.

RECENT FINDINGS

Recent guidelines for the treatment of hypertension (Joint National Committee on Prevention, Detection, and Treatment of High Blood Pressure VI Report and World Health Organization Guidelines) do not directly address post-transplant hypertension. Specific recommendations for the drug treatment of hypertension in renal allograft recipients have not been given in the Clinical Practice Guidelines of the American Society of Transplantation or those of the European Renal Association.

SUMMARY

The present paper summarizes some important aspects of post-transplant hypertension and discusses potential treatment strategies aimed at reducing blood pressure and thus improving patient and allograft survival.

Associations between use of cyclosporine-sparing agents and outcome in kidney transplant recipients

BACKGROUND

Diltiazem, widely used as a cyclosporine-sparing agent, has been suggested to confer a benefit on graft and patient outcome in kidney transplantation related to immunomodulatory properties. Use of cyclosporine-sparing agents (CsSpA) is routinely recorded by the Australia & New Zealand Dialysis and Transplant (ANZDATA) Registry, and we used these data to examine the associations between CsSpA use and outcomes.

METHODS

Graft and patient survival were analyzed for a cohort of 3913 people who received kidney transplants in Australia or New Zealand between 1 April 1993 and 30 March 2001. Patients were followed to death or loss of graft function. Graft and patient survival analyses were performed using Cox proportional hazards models, including a time varying covariate for CsSpA use in analyses of graft failure. Occurrence of delayed graft function (DGF) and acute rejection also were examined as secondary outcomes.

RESULTS

There was no difference in patient survival in the first 12 months post transplantation, but from 12 months onwards there is a survival advantage associated with CsSpA use among cadaveric donor (CD) recipients in both univariate hazard ratio (HR) 0.56, 95% CI 0.41 to 0.76, P < 0.001 and multivariate (HR 0.56, 95% CI 0.40 to 0.79, P < 0.001) analyses. This was consistent across subgroups examined. Lower rates of early graft loss (censored for death) were associated with CsSpA use [odds ratio (OR) 0.61, 95% CI 0.50 to 0.75, P < 0.0001]. Lower rates of use of antibody therapy for rejection also were observed, but not lower rates of biopsy-proven rejection.

CONCLUSIONS

CsSpA use was associated with improved patient mortality after kidney transplantation. Whether this was a direct drug effect or due to other factors associated with diltiazem use cannot be inferred directly from these data, although several plausible mechanisms exist which might mediate a diltiazem effect.

Predictors of renal function following lung or heart-lung transplantation

BACKGROUND

Renal failure is a common complication following non-renal solid organ transplantation. The purpose of our study was to define the rate of decline in renal function and to identify independent risk factors associated with renal failure following lung or heart-lung transplantation.

METHODS

Between May 1986 and December 1998, 219 patients underwent lung or heart-lung transplantation at the University of Minnesota and survived at least six months (33 heart-lung, 66 bilateral single lung, and 120 unilateral single lung transplants). The mean age at the time of transplant was 45.9 +/- 11.6 years (mean +/- SD; range, 15 to 65 years), and the mean pre-transplant serum creatinine level was 0.88 +/- 0.19 mg/dL. All patients were treated with a calcineurin inhibitor (164 cyclosporine, 55 tacrolimus).

RESULTS

During the follow-up period (median 44 months, range 6.8 to 163 months), 16 patients (7.3%) developed end-stage renal disease. The cumulative incidence of doubling of serum creatinine was 34% at one year, 43% at two years and 53% by five years. Factors associated with the primary end point of the time to doubling of the baseline serum creatinine by proportional hazards regression were cumulative periods with diastolic blood pressure greater than 90 mm Hg [relative risk (RR) 1.30, P = 0.02] and the serum creatinine value at one month post-transplantation (RR 1.28, P = 0.03). Use of tacrolimus during the first six months after transplantation was associated with a significant decrease in the risk for time to doubling of serum creatinine (RR 0.38, P = 0.009) and a lower rate of acute rejection.

CONCLUSIONS

These results suggest that potential renoprotective strategies following lung or heart-lung transplantation include avoidance of peri-transplant renal injury, diligent blood pressure control, and preferential use of tacrolimus over cyclosporine.

Routine renin-angiotensin system blockade in renal transplantation?

There is ample evidence to support the recommendation of renin-angiotensin system blockade therapy as the standard of care for strategies aimed at preserving renal function in chronic renal disease. Nevertheless, despite the well established antihypertensive effects of these drugs, the use of renin-angiotensin system blockers in renal transplantation has been quite limited so far, nephrologists being afraid of the possibility of inducing renal insufficiency in patients with a single kidney transplant. However, current knowledge of the ability of these agents to control blood pressure and urinary protein excretion, as well as post-transplant erythrocytosis, effectively in kidney transplant recipients suggests that it is now time to apply renin-angiotensin system blockers to the field of renal transplantation.

Sustained improvement of renal graft function for two years in hypertensive renal transplant recipients treated with nifedipine as compared to lisinopril

BACKGROUND

Treatment of posttransplant hypertension is still a matter of debate. Calcium antagonists may ameliorate renal side effects of cyclosporin. Angiotensin converting enzyme- (ACE) inhibitors may be more effective in sustaining renal function in native chronic renal disease. We prospectively compared the effect of controlled release nifedipine and lisinopril on long-term renal function in hypertensive kidney transplant patients treated with cyclosporin.

METHODS

A total of 154 renal transplant patients presenting with hypertension (diastolic blood pressure >or=95 mmHg) during the first 3 weeks after transplantation were randomised to receive double-blind nifedipine 30 mg or lisinopril 10 mg once daily. A total of 123 patients completed 1 year of treatment (69 nifedipine, 54 lisinopril) and 64 patients completed 2 years of double-blind treatment (39 nifedipine, 25 lisinopril). Baseline glomerular filtration rate was measured as 99 mTc-diethylene-triaminepentaacetate clearance in a stable phase 2 to 5 weeks after inclusion and repeated at 1 and 2 years.

RESULTS

Baseline glomerular filtration rates were similar (46+/-16 ml/min with nifedipine, 43+/-14 ml/min with lisinopril). The changes in glomerular filtration rates from baseline were statistically significant between the groups after 1 year (9.6 ml/min mean treatment difference (95% confidence interval [CI]s 5.5-13.7 ml/min, P=0.0001) and remained statistically significant also after 2 years (10.3 ml/min mean difference (95% CIs 4.0-16.6], P=0.0017). After 1 year glomerular filtration rates averaged 56+/-19 ml/min in the nifedipine group and 44+/-14 ml/min in the lisinopril group.

CONCLUSIONS

Both nifedipine and lisinopril were safe and effective in treatment of hypertension in renal transplant patients treated with cyclosporin. Patients receiving nifedipine but not lisinopril improved kidney transplant function over a period of 2 years.

Efficacy of nifedipine or lisinopril in the treatment of hypertension after renal transplantation: a double-blind randomised comparative trial

Calcium channel blockers and angiotensin converting enzyme-inhibitors are commonly used in the treatment of hypertensive renal transplant recipients. The purpose of this study was to investigate if the response rate to treatment differs with these drugs in this setting. A single centre, prospective, randomised, double-blinded, comparative study to address the efficacy of controlled release nifedipine or lisinopril in the treatment of hypertension (diastolic blood pressure > or =95 mmHg) in cyclosporin (CsA)-treated renal transplant recipients was performed. Recipients were randomised to receive either lisinopril (10 mg once daily) or controlled release nifedipine (30 mg once daily). The dose was doubled on indication. The number of responders (diastolic blood pressure <90 mmHg on monotherapy) were addressed during the early post-transplant phase (first 3 months) and during a late post-transplant phase (from 3 to 12 months after renal transplantation) in the same patient population. One hundred and fifty-four patients (nifedipine=78, lisinopril=76) with untreated hypertension (diastolic blood pressure> or =95 mmHg) were randomised within 3 wk after renal transplantation. One hundred and twenty-three patients (nifedipine=69, lisinopril=54) completed the study. Fourteen (20%) nifedipine-treated recipients responded during the early, and 26 (38%) during the late post-operative phase (months 4-12 after renal transplantation). Eleven (20%) lisinopril-treated recipients responded during the early, and 18 (33%) during the late post-transplant phase. Non-responders were, on average, 8.5+/-1.5 kg heavier both in the early phase and after 1 yr of treatment (p<0.01), and 6.1+/-0.9 yr older than responders (p<0.05). In conclusion, these results indicate that both controlled release nifedipine and lisinopril are equally efficient in the treatment of post-transplant hypertension. As monotherapy, both drugs show a "response rate" of 20-38%, depending on time interval after transplantation.

Risk factors for and management of post-transplantation cardiovascular disease

The mortality rates due to cardiovascular disease (CVD) in transplant recipients are greater than in the general population. CVD is a major cause of both graft loss and patient death in renal transplant recipients, and improving cardiovascular health in transplant recipients will presumably help to extend both patient and graft survival. Further studies are needed to better evaluate the effectiveness of risk modification on subsequent CVD morbidity and mortality. There is no reason to consider risk factors for CVD such as hyperlipidaemia, hypertension and diabetes mellitus in transplant recipients differently from in the general population. In addition, there are specific transplantation risk factors such as acute rejection episodes and the use of immunosuppressive drugs. It is obvious that several of the immunosuppressive agents used today have disadvantageous influences on risk factors for CVD such as hyperlipidaemia, hypertension and post-transplantation diabetes mellitus (PTDM), but the relative importance of immunosuppressant-induced increases in these risk factors is basically unknown. This may be a strong argument for the selective use and individual tailoring of immunosuppressive agents based upon the risk factor profile of the patient, without jeopardising the function of the graft. Hyperlipidaemia is common after transplantation, and immunosuppression with corticosteroids, cyclosporin, or sirolimus (rapamycin) causes different types of post-transplantation hyperlipidaemia. However, to date, no studies have demonstrated that lipid lowering strategies significantly reduce CVD morbidity or mortality and improve allograft survival in transplant recipients. Several studies using preventive or interventional approaches are ongoing and will be reported in the near future. Post-transplantation hypertension appears to be a major risk factor determining graft and patient survival, and immunosuppressive agents have different effects on hypertension. Controlled studies support the opinion that post-transplantation hypertension must be treated as strictly as in a population with essential hypertension, diabetes mellitus, or chronic renal failure. As increasing numbers of immunosuppressive agents become available for use, we may be in a better position to tailor immunosuppressive therapy to the individual patient, avoiding the use of diabetogenic drugs, drug combinations, or inappropriate doses in patients susceptible to PTDM. Multiple acute rejection episodes have also been demonstrated to be a risk factor for CVD - a strong argument for the use of immunosuppressive drugs to reduce acute rejection. Until we have a better understanding from ongoing landmark studies on the management of CVD, presently available therapy to reduce risk factors needs to be used together with individual tailoring of immunosuppressive therapy with the aim of reducing CVD in these patients.

Cyclosporin A increases basal intracellular calcium and calcium responses to endothelin and vasopressin in human coronary myocytes

Cyclosporin A (CsA) is a widely used immunosuppressive agent with severe side effects including hypertension. Here, we investigated the effects of CsA on intracellular free calcium ([Ca(2+)](i)) and the mechanisms involved in vasoconstriction in cultured human coronary myocytes. We used the Fura-2 technique for Ca(2+) imaging. Acute application of CsA at therapeutic concentrations (0.1-10 micromol/l) had no effect. Chronic exposure to CsA (1 micromol/l) for 24 h induced a small (20 nmol/l) but highly significant increase of basal [Ca(2+)](i) and enhanced the occurrence of spontaneous Ca(2+) oscillations. Endothelin- and vasopressin-induced rises of [Ca(2+)](i) were also enhanced. The demonstration that CsA increases basal [Ca(2+)](i) in addition to its impact on agonist receptor stimulation is of major importance for new therapeutic approaches.