Role of steroid dose in hypertension early after liver transplantation with tacrolimus (FK506) and cyclosporine

Approach and Management of Hypertension After Kidney Transplantation

Hypertension is one of the most common cardiovascular co-morbidities after successful kidney transplantation. It commonly occurs in patients with other metabolic diseases, such as diabetes mellitus, hyperlipidemia, and obesity. The pathogenesis of post-transplant hypertension is complex and is a result of the interplay between immunological and non-immunological factors. Post-transplant hypertension can be divided into immediate, early, and late post-transplant periods. This classification can help clinicians determine the etiology and provide the appropriate management for these complex patients. Volume overload from intravenous fluid administration is common during the immediate post-transplant period and commonly contributes to hypertension seen early after transplantation. Immunosuppressive medications and donor kidneys are associated with post-transplant hypertension occurring at any time point after transplantation. Transplant renal artery stenosis (TRAS) and obstructive sleep apnea (OSA) are recognized but common and treatable causes of resistant hypertension post-transplantation. During late post-transplant period, chronic renal allograft dysfunction becomes an additional cause of hypertension. As these patients develop more substantial chronic kidney disease affecting their allografts, fibroblast growth factor 23 (FGF23) increases and is associated with increased cardiovascular and all-cause mortality in kidney transplant recipients. The exact relationship between increased FGF23 and post-transplant hypertension remains poorly understood. Blood pressure (BP) targets and management involve both non-pharmacologic and pharmacologic treatment and should be individualized. Until strong evidence in the kidney transplant population exists, a BP of <130/80 mmHg is a reasonable target. Similar to complete renal denervation in non-transplant patients, bilateral native nephrectomy is another treatment option for resistant post-transplant hypertension. Native renal denervation offers promising outcomes for controlling resistant hypertension with no significant procedure-related complications. This review addresses the epidemiology, pathogenesis, and specific etiologies of post-transplant hypertension including TRAS, calcineurin inhibitor effects, OSA, and failed native kidney. The cardiovascular and survival outcomes related to post-transplant hypertension and the utility of 24-h blood pressure monitoring will be briefly discussed. Antihypertensive medications and their mechanism of actions relevant to kidney transplantation will be highlighted. A summary of guidelines from different professional societies for BP targets and antihypertensive medications as well as non-pharmacological interventions, including bilateral native nephrectomy and native renal denervation, will be reviewed.

A new donors' CYP3A5 and recipients' CYP3A4 cluster predicting tacrolimus disposition, and new-onset hypertension in Chinese liver transplant patients

AIM

The purpose of the current study was to investigate individualized therapy of tacrolimus (Tac), as well as complications after liver transplantation (LT) with the known genetic determinants and clinical factors.

METHODS

In this retrospective study, two cohorts (n=170) from the China Liver Transplant Registry (CLTR) database from July 2007 to March 2015 were included.

RESULTS

Both donors' CYP3A5*3 and recipients' CYP3A4*1G had a correlation with Tac pharmacokinetics at four weeks (all P<0.05), except recipients' CYP3A4*1G nearly had an association at week 2 (P=0.055). The model of donors' CYP3A5*3, recipients' CYP3A4*1G, and total bilirubin (TBL), for the prediction of Tac disposition, was better than donors' CYP3A5*3 only at week 1, 2, and 3 (P=0.010, P=0.007, and P=0.010, respectively), but not apparent at week 4 (P=0.297). Besides, when the P value was greater than or equal to 0.6685 after considering the false-positive rate R=10%, the patients were considered to have a faster metabolism, according to the mentioned model. Interestingly, we found that if more than or equal to two alleles A were present in the combination of donors' CYP3A5*3 and recipients' CYP3A4*1G genotype, there was a lower Tac C/D ration at week 1, 2, and 3 (P<0.001, P=0.001, and P<0.001), except at week 4 (P=0.082), and the probability of new-onset hypertension was lesser (P<0.001).

CONCLUSIONS

These data provided a potential basis for a comprehensive approach to predicting the Tac dose requirement in individual patients and provided a strategy for the effective prevention, early diagnosis of new-onset hypertension in Chinese LT recipients.

Hypertension after kidney transplantation: a pathophysiologic approach

Post-transplant hypertension is associated with decreased graft and patient survival and cardiovascular morbidity. Unfortunately, post-transplant hypertension is often poorly controlled. Important risk factors include immunosuppressive medications, complications of the transplant surgery, delayed graft function, rejection, and donor and recipient risk factors. The effects of immunosuppressive medications are multifactorial including increased vascular and sympathetic tone and salt and fluid retention. The immunosuppressive agents most commonly associated with hypertension are glucocorticoids and calcineurin inhibitors. Drug therapy for hypertension should be based on the comorbidities and pathophysiology. Evidence-based approaches to defining and treating hypertension in renal transplant recipients are predominantly extrapolated from large-scale studies performed in the general population. Thus, there continues to be a need for larger studies examining the pathophysiology, diagnosis and treatment of hypertension in renal transplant recipients.

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.

Molecularly Engineered Islet Cell Clusters for Diabetes Mellitus Treatment

Pancreatic islet transplantation is a promising method for curing diabetes mellitus. We proposed in this study a molecularly engineered islet cell clusters (ICCs) that could overcome problems posed by islet transplantation circumstances and host's immune reactions. A gene containing highly releasable exendin-4, an insulinotropic protein, was delivered into single islet cells to enhance glucose sensitivity; thereafter, the cells were reaggregated into small size ICCs. Then the surface of ICCs was modified with biocompatible poly(ethylene glycol)-lipid (PEG) (C18) for preventing immune reactions. The regimen of ICCs with low doses of anti-CD154 mAb and tacrolimus could effectively maintain the normal glucose level in diabetic mice. This molecularly engineered PEG-Sp-Ex-4 ICC regimen prevented cell death in transplantation site, partly through improving the regulation of glucose metabolism and by preventing hypoxia- and immune response-induced apoptosis. Application of this remedy is also potentially far-reaching; one would be to help overcome islet supply shortage due to the limited availability of pancreas donors and reduce the immunosuppressant regimens to eliminate their adverse effects.

Abnormal circadian blood pressure regulation in liver transplanted children

HT is a frequent cardiovascular risk factor in liver transplant recipients. However, there are only few studies in the literature regarding the risk of HT in liver transplanted children. The aim of this study was to assess the 24 h BP profiles of liver transplanted patients and to compare the results with healthy children. ABPM was performed on 20 liver transplanted patients and 27 healthy children aged 7.1 ± 4.8 and 8.5 ± 2.9 yr, respectively. HT was defined as SDS > 1.64 (i.e., >95th percentile) adjusted for gender and height. The mean duration of post-transplant follow-up was 32 ± 19 months. Six (30%) patients were found to be hypertensive. The physiological nocturnal BP fall was attenuated significantly in the study group for diastolic BP (11.5 ± 6.1 mmHg vs. 17.7 ± 7.1 mmHg, p = 0.006). Specifically, the number of patients with high nighttime systolic and diastolic BP SDS (p = 0.02 and p = 0.004, respectively) as well as elevated nighttime systolic (p = 0.03) and diastolic (p = 0.003) BPLs was found to be significantly higher than those in the controls. Alteration of the "normal" circadian rhythm is very frequent in liver transplant recipients. Thus, it is recommended to perform ABPM on all liver transplanted children not to underdiagnose HT.

Metabolic syndrome and its components after liver transplantation: incidence, prevalence, risk factors, and implications

Metabolic syndrome is defined as the mutual existence of obesity, impaired fasting glucose levels, insulin resistance, hypertension, and dyslipidemia. After liver transplantation, patients typically develop these disorders, and even though there has been minimal research focused on the chronic impact of this syndrome on post-liver transplant patients, studies point to an association with major vascular events and fibrosis. The aim of the current work is to review data on the incidence, prevalence, risk factors, and implications of metabolic syndrome and its components in patients who have undergone liver transplantation.

A peptide-major histocompatibility complex II chimera favors survival of pancreatic beta-islets grafted in type 1 diabetic mice

BACKGROUND

Transplantation of pancreatic islets showed a tremendous progress over the years as a promising, new therapeutic strategy in patients with type 1 diabetes. However, additional immunosuppressive drug therapy is required to prevent rejection of engrafted islets. The current immunosuppressive therapies showed limited success in maintaining long-term islet survival as required to achieve insulin independence in type 1 diabetes, and they induce severe adverse effects. Herein, we analyzed the effects of a soluble peptide-major histocompatibility complex (MHC) class II chimera aimed at devising an antigen-specific therapy for suppression of anti-islet T cell responses and to improve the survival of pancreatic islets transplants.

METHODS

Pancreatic islets from transgenic mice expressing the hemagglutinin antigen in the beta islets under the rat insulin promoter (RIP-HA) were grafted under the kidney capsule of diabetic, double transgenic mice expressing hemagglutinin in the pancreas and T cells specific for hemagglutinin (RIP-HA, TCR-HA). The recipient double transgenic mice were treated or not with the soluble peptide-MHC II chimera, and the progression of diabetes, graft survival, and T cell responses to the grafted islets were analyzed.

RESULTS

The peptide-MHC II chimera protected syngeneic pancreatic islet transplants against the islet-reactive CD4 T cells, and prolonged the survival of transplanted islets. Protection of transplanted islets occurred by polarization of antigen-specific memory CD4 T cells toward a Th2 anti-inflammatory response.

CONCLUSIONS

The peptide-MHC II chimera approach is an efficient and specific therapeutic approach to suppress anti-islet T cell responses and provides a long survival of pancreatic grafted islets.

EULAR evidence-based recommendations on the management of systemic glucocorticoid therapy in rheumatic diseases

OBJECTIVE

To develop evidence-based recommendations for the management of systemic glucocorticoid (GC) therapy in rheumatic diseases.

METHODS

The multidisciplinary guideline development group from 11 European countries, Canada and the USA consisted of 15 rheumatologists, 1 internist, 1 rheumatologist-epidemiologist, 1 health professional, 1 patient and 1 research fellow. The Delphi method was used to agree on 10 key propositions related to the safe use of GCs. A systematic literature search of PUBMED, EMBASE, CINAHL, and Cochrane Library was then used to identify the best available research evidence to support each of the 10 propositions. The strength of recommendation was given according to research evidence, clinical expertise and perceived patient preference.

RESULTS

The 10 propositions were generated through three Delphi rounds and included patient education, risk factors, adverse effects, concomitant therapy (ie, non-steroidal anti-inflammatory drugs, gastroprotection and cyclo-oxygenase-2 selective inhibitors, calcium and vitamin D, bisphosphonates) and special safety advice (ie, adrenal insufficiency, pregnancy, growth impairment).

CONCLUSION

Ten key recommendations for the management of systemic GC-therapy were formulated using a combination of systematically retrieved research evidence and expert consensus. There are areas of importance that have little evidence (ie, dosing and tapering strategies, timing, risk factors and monitoring for adverse effects, perioperative GC-replacement) and need further research; therefore also a research agenda was composed.

Highly Poly(Ethylene) Glycolylated Islets Improve Long-Term Islet Allograft Survival without Immunosuppressive Medication

The surface modification of islets using poly(ethylene glycol) (PEG) is being studied as a means of preventing host immune responses against transplanted islets. In this study, to completely shield islets with PEG molecules, we increased the amount of PEG conjugated to islet surfaces, by multiple PEGylation or amplified PEGylation using poly-L-lysine, poly(allylamine), or poly(ethyleneimine), respectively. Amplified PEGylation was associated with islet cytotoxicity and functional impairment, but multiple PEGylation affected neither islet viability nor functionality. In addition, when triply PEGylated islets were allotransplanted into diabetic recipients, these islets survived in 3 of the 7 recipients for more than 100 days without any immunosuppressive treatment. Moreover, the blood glucose levels of these 3 recipients were stable and in the normal range. Immunohistochemical analysis showed that 3 of 7 triply PEGylated islets transplants survived for 100 days and that 4 that were rejected before day 20 were all immunologically protected from immune cells. However, unmodified islets were completely destroyed within 1 week. Consequently, we suggest that multiple PEGylation offers an effective means of reducing the immunogenicity of transplanted islets by increasing the amount of surface-bound PEG.

Functional and histological evaluation of transplanted pancreatic islets immunoprotected by PEGylation and cyclosporine for 1 year

Pancreatic islet transplantation is one of the most promising strategies for patients suffering from type 1 diabetes mellitus, but several therapeutic immunosuppressive medications must be administered simultaneously to protect transplanted islets in the long-term, and these expose patients to the risk of serious complications. Thus, we developed chemically modified islets with a protective poly(ethylene glycol) (PEG) layer, which reduces immunogenicity by preventing cellular immune reactions. We report here that PEG-based chemical immunomodulation can provide a semi-permanent effective therapy that protects transplanted islets at least for 1 year when accompanied by cyclosporine. Moreover, this combinatorial approach appears to avoid the toxicities associated with immunosuppressive medications because of the reduced amounts of medication required. Also, the conjugated PEG molecules were found to be continuously present at the transplanted islets. However, unmodified islets (control) were completely eliminated within 2 weeks even when CsA was administered. These results strongly suggest that this new combinatorial therapy provides a semi-permanent, effective clinical means of attenuating transplanted islet immunogenicity for a long time, whilst avoiding the toxicities associated with therapeutic levels of immunosuppressants owing to the minimized immunosuppressant.

Review article: medical management of the liver transplant recipient - a primer for non-transplant doctors

BACKGROUND

Survival 10 years after orthotopic liver transplantation now approaches 65%. Consequently, community doctors must manage the metabolic and neoplastic complications of orthotopic liver transplantation in an ageing population.

AIMS

To review common sources of morbidity and mortality in long-term orthotopic liver transplantation recipients, and to make evidence-based recommendations regarding their management.

METHODS

Pertinent studies and reviews were identified by literature search through PubMed. Where evidence-based recommendations could not be gleaned from the literature, expert opinion was obtained from syllabi of national meetings.

RESULTS

The two most common causes of morbidity and mortality in orthotopic liver transplantation recipients are atherosclerotic vascular disease and de novo malignancy. The pathogenesis of many complications begins before orthotopic liver transplantation, and many are potentially modifiable. Most complications, however, can be directly ascribed to immunosuppressive agents. Despite improvements in our understanding of the pathogenesis and epidemiology of the metabolic and neoplastic complications of orthotopic liver transplantation, remarkably few randomized-controlled studies exist to define their optimal management.

CONCLUSIONS

Orthotopic liver transplantation recipients experience and succumb to the same afflictions of old age as non-transplant patients, but with greater frequency and at an earlier age. Most recommendations regarding surveillance for, and treatment of, medical complications of orthotopic liver transplantation remain based upon expert opinion rather than evidence-based medicine.

A new strategy toward improving immunoprotection in cell therapy for diabetes mellitus: long-functioning PEGylated islets in vivo

Surface modification of islets using poly(ethylene glycol) (PEG) has been studied toward preventing immune responses of host for successful islet transplantation. In this study, we assessed the functionality of PEGylated islets and immune responses of host, as well as the synergistic effects of using PEGylation simultaneously with cyclosporine A (CsA) to prevent immune reactions. The average period of time for which PEGylated islets functioned normally following islets transplantation was 14 days, whereas it was only 5 days for unmodified islets. Host's immune cells did not eliminate the PEGylated islets but were observed to gather around the islets. On the other hand, unmodified islets were completely eliminated. When a low dose of CsA (3 mg/kg/day) was intravenously administered at the same time, the PEGylated islets showed stable activity and survived for 100 days before, that is, the PEGylated islets secreted insulin and were preserved from the immune cells. However, unmodified islets survived for 14 days on the average, even when CsA was administered. Consequently, it can be suggested that the PEGylation of islet surfaces can be an effective approach toward reducing the immunogenecity of islets, thus improving the functionality and survival time of transplanted islets, especially when CsA was simultaneously administered.

Effect of immunosuppressive agents on long-term survival of renal transplant recipients: focus on the cardiovascular risk

In the control of acute rejection, attention is being focused more and more on the long-term adverse effects of the immunosuppressive agents used. Since cardiovascular disease is the main cause of death in renal transplant recipients, optimal control of cardiovascular risk factors is essential in the long-term management of these patients. Unfortunately, several commonly used immunosuppressive drugs interfere with the cardiovascular system. In this review, the cardiovascular adverse effects of the immunosuppressive agents currently used for maintenance immunosuppression are thoroughly discussed. Optimising immunosuppression means finding a balance between efficacy and safety. Corticosteroids induce endothelial dysfunction, hypertension, hyperlipidaemia and diabetes mellitus, and impair fibrinolysis. The use of corticosteroids in transplant recipients is undesirable, not only because of their cardiovascular effects, but also because they induce such adverse effects as osteoporosis, obesity, and atrophy of the skin and vessel wall. Calcineurin inhibitors are the most powerful agents for maintenance immunosuppression. The calcineurin inhibitor ciclosporin (cyclosporine) not only induces these same adverse effects as corticosteroids but is also nephrotoxic. Tacrolimus has a more favourable cardiovascular risk profile than ciclosporin and is also less nephrotoxic. It has little or no effect on blood pressure and serum lipids; however, its diabetogenic effect is more prominent in the period immediately following transplantation, although at maintenance dosages, the diabetogenic effect appears to be comparable to that of ciclosporin. The diabetogenic effect of tacrolimus can be managed by reducing the dose of tacrolimus and early corticosteroid withdrawal. The effect of tacrolimus on endothelial function has not been completely elucidated. The proliferation inhibitors azathioprine and mycophenolate mofetil (MMF) have little effect on the cardiovascular system. Yet, indirectly, by inducing anaemia, they may lead to left ventricular hypertrophy. MMF is an attractive alternative to azathioprine because of its higher potency and possibly lower risk of malignancies. Sirolimus also induces anaemia, but may be promising because of its antiproliferative features. Whether the hyperlipidaemia induced by sirolimus counteracts its beneficial effects is, as yet, unknown. It may be combined with MMF, however, initial attempts resulted in severe mouth ulcers.

A DECADE OF PROGRESS IN KIDNEY TRANSPLANTATION

Kidney transplantation has become the treatment of choice for patients with end-stage renal disease because of better surgical techniques and the availability of more powerful immunosuppressive drugs. Regimens of immunosuppression should combine both short-term outcomes and predictors of long-term safety and survival. The value of tacrolimus for immunosuppression protocols lies in its ability to reduce the immunologic risk to the allograft and its excellent safety profile. Outcomes for kidney-transplant recipients can be further optimized by individualizing therapy to address each patient's risk profile.

Biodegradable microsphere-loaded tacrolimus enhanced the effect on mice islet allograft and reduced the adverse effect on insulin secretion

The adverse effects of tacrolimus have limited the use of this potent immunosuppressive drug in clinical transplantation. To improve the therapeutic effects, we developed a new type of tacrolimus with biodegradable microsphere technology and examined the immunosuppressive effects on allogeneic islet transplantation and the side-effects on insulin secretion in vivo. With a single subcutaneous injection, mouse blood concentrations of tacrolimus (M-FK) carried in biodegradable microspheres remained flat for 2 weeks (only 10 h for conventional tacrolimus). A single subcutaneous administration of 20 mg/kg of M-FK significantly prolonged the survival of islet allografts (MST = 28 days) compared with the control group (MST = 10 days). Series administration of 10 mg/kg of M-FK at 7-day intervals markedly prolonged the survival of islet grafts, and resulted in 60% allograft acceptance. In mice with syngeneic islet transplantations, a single administration of 30 mg/kg of tacrolimus inhibited insulin secretion, whereas a single administration of an equal dosage of M-FK did not. The results suggested that M-FK enhanced the immunosuppressive effects on islet allograft rejection more effectively with reduced side-effects on insulin secretion.

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.

Hypertension after kidney transplantation: impact, pathogenesis and therapy

Hypertension (HTN) contributes to the high incidence of cardiovascular disease mortality as well as chronic allograft nephropathy (CAN) and late graft failure in renal transplant recipients. The mechanisms are complex and may involve pathogenic factors attributable to the host, allograft, and immunosuppressive drugs. Calcium channel blockers should be used to ameliorate the nephrotoxicity of calcineurin inhibitors in the early years after transplantation. Angiotensin-converting enzyme inhibitors and angiotensin-2 type-1 receptor blockers are safe and effective, have antiproteinuric effects, slow the progression of CAN, and may provide survival benefits. Diuretics and/or beta-adrenergic receptor blockers are frequently added in combination regimen. Appropriate adjustment of the immunosuppressive drugs should also be considered for the long-term care of kidney recipients with HTN.

Influence of the new immunosuppressive combinations on arterial hypertension after renal transplantation

Arterial hypertension is highly prevalent after renal transplantation and may contribute to the risk of cardiovascular disease. Also, arterial hypertension has been reported to be an independent risk factor for graft failure. Immunosuppressive drugs such as corticosteroids, cyclosporine and tacrolimus may be important contributing factors to post-transplant hypertension. Recent data from multicenter trials and from conversion studies (cyclosporine to tacrolimus) suggest that renal transplant patients under tacrolimus-based therapy showed less arterial hypertension compared with cyclosporine treated patients. New immunosuppressive drugs, including mycophenolate mofetil and rapamycin, are not nephrotoxic and they do not have any hypertensive effect. New immunosuppressive combinations including mycophenolate mofetil in a triple therapy regimen (associated with corticosteroids and cyclosporine) can reduce blood pressure so that corticosteroids can be stopped or cyclosporine reduced or even eliminated. Non-nephrotoxic regimens using rapamycin (sirolimus) as basic immunosuppression, associated with azathioprine or mycophenolate mofetil, could reduce the incidence of post-transplant arterial hypertension. Also, in renal transplant patients initially immunosuppressed with rapamycin, cyclosporine and corticosteroids, after the elimination of CSA, a lower blood pressure is achieved. In summary, new protocols with mycophenolate mofetil and/or rapamycin may permit several combinations that offer important alternatives to classical immunosuppressive regimens to reduce the incidence and clinical impact of arterial hypertension after renal transplantation.

Different effects of tacrolimus and cyclosporine on renal hemodynamics and blood pressure in healthy subjects

BACKGROUND

The side effects of cyclosporine, nephrotoxicity and hypertension, contribute to long-term renal graft failure and cardiovascular morbidity in graft recipients. It is not clear whether tacrolimus is as nephrotoxic and hypertensive as cyclosporine. Data on this subject are not consistent because of differences in dosage and duration of treatment and the presence of comorbidity in the studied patients. A comparison of both drugs with respect to renal hemodynamics and blood pressure has not been performed yet in healthy subjects.

METHODS

We studied blood pressure, glomerular filtration rate, and effective renal plasma flow in eight healthy subjects at baseline and after 2 weeks administration of cyclosporine and tacrolimus, in randomized order. Trough levels of either drug were within the currently recommended therapeutical range of 100-200 ng/ml for cyclosporine and 5-15 ng/ml for tacrolimus.

RESULTS

Tacrolimus did not influence renal hemodynamic parameters, in contrast to cyclosporine. During cyclosporine, glomerular filtration rate decreased from 98+/-9 ml/min/1.732 to 85+/-10 ml/min/1.732 (P<0.05), and ERPF decreased from 597+/-108 ml/min/1.732 to 438+/-84 ml/min/1.732 (P<0.01). Mean arterial blood pressure increased from 93+/-8 mmHg to 108+/-10 mmHg (P<0.05) during cyclosporine and remained unchanged during tacrolimus.

CONCLUSIONS

We conclude that tacrolimus given during 2 weeks in the currently advised dosage has no unfavorable effects on renal hemodynamics and blood pressure in healthy individuals. The use of tacrolimus in organ transplant recipients may in the long-term lead to better renal function and less cardiovascular morbidity than the use of cyclosporine.

Safety of the new macrolide immunomodulators

With the wide acceptance of cyclosporine in the treatment of skin disease, there has been an effort to find new immunomodulating agents with superior safety profiles for use in dermatology. Among the most promising of the classes are the new macrolide immunomodulators, including tacrolimus and pimecrolimus. Of these, only tocrolimus has had widespread use for nondermatologic indications, primarily solid organ transplantation. Both of these agents have been studied for inflammatory diseases of the skin. In this article, we review the systemic and topical toxicities of these macrolide immunomodulators.

Hypertension after renal transplantation

With current immunosuppression, elevated blood pressure is found in almost 90% of renal graft recipients. Major causes of this are impairment of renal function (secondary to chronic allograft nephropathy or less frequently recurrence of primary renal disease), the use of calcineurin inhibitors as immunosuppressants, uncontrolled renin secretion by the shrunken kidneys of the recipient, stenosing lesions of the transplant artery (or the upstream arteries of the recipient), polycythemia, and genetic predisposition to hypertension of the graft donor. Even minor degrees of blood pressure elevation have a significant impact on survival of the recipient and on graft survival, presumably by amplifying vascular injury to the graft. In this respect, elevation of systolic blood pressure and an abnormal circadian blood pressure profile are of particular relevance. In contrast to previous opinion, angiotensin converting enzyme inhibitors are indicated in treatment, but given the causal role of sodium retention and graft vasoconstriction, diuretics and calcium channel blockers remain mainstays of antihypertensive treatment in the renal allograft recipient.

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.

Low rejection rates with tacrolimus-based dual and triple regimens following liver transplantation

We studied the outcome of 345 liver transplant patients who received tacrolimus-based immunosuppressive therapy either as a dual regimen (with corticosteroids, n=172) or as a triple regimen (with corticosteroids and azathioprine, n=173) for 3 months after transplantation (3-month cohort). A further analysis was conducted for the first 195 patients randomised (dual n=100, triple n=95) who were followed up for 12 months after transplantation (12-month cohort). For the 3-month cohort, patient survival was 90.7% (dual) and 91.9% (triple), graft survival after 3 months was 88.4% (dual therapy) and 89.6% (triple therapy). Acute rejections were experienced by 67/172, 39.0% of patients on dual therapy and by 60/173, 34.7% of patients on triple therapy; corticosteroid-resistant rejections were reported in 9 patients (5.2%) in either treatment group. The overall safety profile was similar for the two treatment groups. Significant differences, however, were found for thrombocytopenia (dual 13/172, 7.6%, triple 37/173, 21.4%, p<0.001) and leukopenia (dual 4/172, 2.3%, triple 24/173, 13.9%, p<0.001). For the 12-month cohort, patient survival was 85.6% (dual) and 88.4% (triple) after 1 year. Graft survival was 81.7% (dual) and 85.2% (triple) 12 months after transplantation. Acute rejections were reported for 38/100, 38.0% of patients on dual therapy and 36/95, 37.9% of patients on triple therapy, corticosteroid-resistant rejections were 7/100, 7.0% (dual) and 7/95, 7.4% (triple) of patients. In the 12-month cohort, no significant differences in the safety profiles of the treatment groups were found. We conclude that both tacrolimus-based dual and triple drug regimens provide effective and safe immunosuppression following orthotopic liver transplantation.

Beneficial effects of converting liver transplant recipients from cyclosporine to tacrolimus on blood pressure, serum lipids, and weight

Hypertension and hyperlipidemia are more prevalent after liver transplantation with cyclosporine as the primary immunosuppressive agent compared with tacrolimus. To determine whether blood pressure, serum lipid level, or weight improves when patients switch immunosuppression therapy, we retrospectively studied 26 liver transplant recipients with stable graft function who had been converted from cyclosporine to tacrolimus therapy with a median follow-up of 8 months. One of the 26 patients developed pruritus necessitating withdrawal of tacrolimus. The results therefore concern the remaining 25 patients. With the exception of a small decrease in bilirubin level (P <.05), there was no difference in graft or renal function after conversion. Mean systolic blood pressure decreased from 158 +/- 25 to 148 +/- 22 mm Hg over a mean of 8 +/- 3 months after conversion to tacrolimus (P =.015), whereas mean serum cholesterol level decreased from 5.3 +/- 0.9 to 4.9 +/- 0.9 mmol/L (P =.01). Sixty-eight percent of the patients lost weight, from a mean of 79.4 +/- 22.6 to 76.1 +/- 20.1 kg, in the 11 months after switching to tacrolimus therapy (P =.024). Serum triglyceride and blood glucose levels did not change, and no patient developed diabetes mellitus after conversion. These results indicate that switching from cyclosporine to tacrolimus can reduce blood pressure, serum cholesterol level, and weight after liver transplantation.

Applications of tacrolimus for the treatment of skin disorders

During the last decades, systemic and topical glucocorticosteroids assumed a dominant role in immunosuppressive therapy in dermatology. However, their administration is limited because of numerous adverse effects. Consequently, there is a large need for alternative non-steroidal anti-inflammatory therapeutics with a superior risk/benefit ratio. In recent years, a new class of anti-inflammatories, the macrolide lactones, has attracted special interest. During the last decade, a member of this class, tacrolimus, proved to be a powerful suppressor of the immune system. Introduced into clinical practice to prevent allograft rejection, it is now routinely used in organ transplantation. Recently, several placebo-controlled multicenter studies showed the therapeutic efficiency of systemic and topical tacrolimus in common inflammatory skin diseases such as psoriasis and atopic eczema.Short-term tacrolimus ointment therapy disclosed significant efficacy vs. placebo and a safety profile with only few local side effects in patients with atopic eczema. Further clinical trials including greater extent of exposure (experienced by children), and comparison between tacrolimus ointment and glucocorticosteroids are being conducted and the results will show whether this drug opens a new era in the treatment of inflammatory skin disorders. The aim of this review is to summarize the current knowledge regarding the pharmacokinetic properties, adverse effects and therapeutic indications of tacrolimus in dermatology.

Mechanisms of hypertension after renal transplantation

Hypertension is extremely prevalent after renal transplantation, affecting up to 70% of all patients. An elevation in blood pressure is associated with an increased cardiovascular risk and may also contribute to chronic allograft failure. Renal transplantation provides interesting insights into the pathogenesis of hypertension. Experimental and human data show that the kidney is an essential organ for blood pressure regulation. In clinical practice a differential diagnosis that is based on excretory allograft function has proved useful.

Role of sympathetic nervous system in cyclosporine-induced rise in blood pressure

To clarify the role of the sympathetic nervous system in the development of cyclosporine A (CsA)-induced rise in blood pressure (BP), the effects of CsA on 24-hour ambulatory BP (ABP) were studied in patients with familial amyloid polyneuropathy (FAP) who underwent a liver transplantation. On the basis of autonomic function tests, patients with absent or mild-to-moderate sympathetic damage (Group A, n=11, age 29 to 43 years, disease duration 2 to 6 years) and patients with severe sympathetic damage (Group B, n=9, age 27 to 38 years, disease duration 3 to 9 years) were identified. Both groups were followed for 1 year. The daily doses of CsA and the CsA whole blood trough levels between the groups did not differ. Pretransplantation values of daytime and nighttime ABP were, respectively, 117+/-8/76+/-7 mm Hg and 108+/-12/68+/-9 mm Hg in group A and 107+/-6/66+/-4 mm Hg (P<0.05 group A versus group B) and 102+/-6/62+/-4 mm Hg in group B. In response to CsA, BP increased in all patients, but more so in patients of group B than in patients of group A. One year after transplantation, daytime and nighttime ABP had increased by 6+/-9/3+/-11% and 12+/-10/14+/-14% in group A and by 12+/-6/13+/-10% (P<0.05) and 21+/-11/27+/-21% (P<0.01) in group B. In both groups, the increase in nighttime ABP was greater than the increase in daytime ABP, which resulted in an attenuation or, even, a reversal of the diurnal BP rhythm. Because the rise in BP was greater in patients with more advanced sympathetic dysfunction, the sympathetic nervous system appears to counteract the CsA-induced rise in BP rather than causing it. This implies involvement of factors other than sympathetic activation in the pathogenesis of CsA-induced rise in BP in patients with familial amyloid polyneuropathy.

Cyclosporin nephrotoxicity: pathophysiology and comparison with FK-506

At the end of an era of almost exclusive use of cyclosporin A, there have been significant advances in the understanding of its immunosuppressive effects, whereas there is still uncertainty about the mechanisms underlying its nephrotoxicity. The recently introduced FK-506, in spite of its undeniable clinical advantages, has subsequently been proved to have rather similar nephrotoxicity. This paper reviews recent data on cyclosporin A and FK-506 nephrotoxicity, with emphasis on: first, the haemodynamic, functional and structural features; second, the potential mediators; and third, the relationship with some immunosuppressive mechanisms involved to give insights into the pathophysiology.

Late hypertension after liver transplantation: a comparison of cyclosporine and tacrolimus (FK 506)

Hypertension frequently develops early after liver transplantation when cyclosporine-based immunosuppression is used. However, initial experience with tacrolimus has suggested that its use leads to a lower early incidence of hypertension. In this study, the blood pressure status of patients treated with cyclosporine (n = 131) and those treated with tacrolimus (n = 28) was compared 24 months after liver transplantation. At this time interval, the prevalence of hypertension in the cyclosporine and tacrolimus groups were 82% and 64%, respectively (P < .05). For those patients who were hypertensive by 24 months, onset was delayed in the tacrolimus group compared with the cyclosporine group: 40% versus 71% and 73% versus 93% at 1 and 12 months, respectively (P < .05). Within the cyclosporine group, patients with hypertension were heavier than those with normal blood pressure, 84.7 +/- 1.8 versus 73.4 +/- 4.0 kg, respectively (P < .05). Within the tacrolimus group, hypertensive patients had lower glomerular filtration rates and higher renal vascular resistances compared with normotensive patients, 74 +/- 12 versus 47 +/- 6 mL/min and 15,711 +/- 2,445 versus 28,830 +/- 4,310 dyne/s/cm5/m2, respectively (P < .05). There were no within-group differences for age, gender, pretransplant history of hypertension, family history of hypertension, graft function, or daily doses of prednisone, cyclosporine, or tacrolimus. These results indicate that, compared with cyclosporine, the onset of hypertension after liver transplantation is delayed and less prevalent with tacrolimus. Additionally, hypertension is associated with increased body weight in cyclosporine-treated patients and with more severe renal dysfunction in patients receiving tacrolimus. The relationships of these findings to the development of posttransplant hypertension requires further study.