Mycophenolate mofetil for secondary prevention of cardiac allograft vasculopathy: influence on inflammation and progression of intimal hyperplasia

The Role of TGF-β Signaling in Saphenous Vein Graft Failure after Peripheral Arterial Disease Bypass Surgery

Saphenous vein bypass grafting is an effective technique used to treat peripheral arterial disease (PAD). However, restenosis is the major clinical challenge for the graft vessel among people with PAD postoperation. We hypothesize that there is a common culprit behind arterial occlusion and graft restenosis. To investigate this hypothesis, we found TGF-β, a gene specifically upregulated in PAD arteries, by bioinformatics analysis. TGF-β has a wide range of biological activities and plays an important role in vascular remodeling. We discuss the molecular pathway of TGF-β and elucidate its mechanism in vascular remodeling and intimal hyperplasia, including EMT, extracellular matrix deposition, and fibrosis, which are the important pathways contributing to stenosis. Additionally, we present a case report of a patient with graft restenosis linked to the TGF-β pathway. Finally, we discuss the potential applications of targeting the TGF-β pathway in the clinic to improve the long-term patency of vein grafts.

Effects of mycophenolate mofetil on transplant coronary artery disease and survival following cardiac transplantation

Cardiac allograft vasculopathy is a leading cause of death in patients undergoing cardiac transplantation. This disease of coronary arteries in characterized by diffuse intimal thickening and narrowing of the vessel lumen. Mycophenolate mofetil (MMF) is a prodrug that is efficiently metabolized to mycophenolic acid (MPA) and which is an effective suppressor of T and B lymphocyte proliferation. MMF also leads to inhibition of lymphocyte adhesion and migration, smooth muscle proliferation. these mechanisms lead to decreased cellular rejection and in a controlled clinical trial MMF, compared to azathioprine, has been demonstrated to improve patient survival, in part by diminishing deaths due to cardiovascular causes. MMF has also been demonstrated to reduce titres of anti-vimentin antibodies, which have been shown to be a marker for increased risk of coronary vascular disease. Data from intravascular ultrasound, angiography and autopsies suggest that MMF by diminish the development of cardiac allograft vasculopathy, which may explain the improvement in survival observed after MMF therapy.

Medication management of cardiac allograft vasculopathy after heart transplantation

Cardiac allograft vasculopathy (CAV) is a common complication following heart transplantation (HT), resulting in diminished graft survival. The preferred strategy for preventing CAV is optimal medical management; however, for patients who develop CAV, delaying disease progression through effective medication management is equally important. A review of the literature regarding medication management of CAV was conducted via a search of the MEDLINE database. Studies were included if they were published in English, conducted in humans ≥ 18 years of age or older, and used noninvestigational medications. Immunosuppressive medications such as the antiproliferative mycophenolate, the calcineurin inhibitor tacrolimus, and the proliferation signal inhibitors sirolimus and everolimus have been shown to prevent the development of CAV. Certain cardiovascular medications, such as HMG-CoA reductase inhibitors (statins), gemfibrozil, calcium channel blockers, and angiotensin-converting enzyme inhibitors, have also demonstrated efficacy in preventing this disease process. Prevention of CAV has also been observed with prophylaxis against cytomegalovirus infection and antioxidant medications. Despite being commonly used in HT patients, neither antiplatelet agents nor glycemic control have proved effective at preventing CAV. Only sirolimus has been shown to arrest the progress of existing CAV.

Delta Neutrophil Index as a Marker for Differential Diagnosis between Acute Graft Pyelonephritis and Acute Graft Rejection

Introduction

The delta neutrophil index (DNI) is the fraction of circulating immature granulocytes, which reflect infectious and/or septic condition. Acute graft pyelonephritis (AGPN) versus acute graft rejection is a frequently encountered diagnostic and therapeutic dilemma in kidney transplant recipients, but little is known about the clinical usefulness of DNI value in the differentiation of the two conditions.

Material & Methods

A total of 90 episodes of AGPN or acute graft rejection were evaluated at the Kangdong Sacred Heart Hospital between 2008 and 2014. We performed retrospective analysis of demographic, clinical, and laboratory parameters data. Receiver operating curves (ROC) and multivariate logistic regression were conducted to ascertain the utility of DNI in discriminating between AGPN and acute graft rejection.

Results

AGPN group had significantly higher DNI values than acute graft rejection group (2.9% vs. 1.9%, P < 0.001). The area under the ROC curve for DNI value to discriminate between AGPN and acute graft rejection was 0.85 (95% confidence interval [CI]; 0.76–0.92, P < 0.001). A DNI value of 2.7% was selected as the cut-off value for AGPN, and kidney transplant recipients with a DNI value ≥ 2.7% were found to be at a higher risk of infection than those with a DNI < 2.7% (odd ratio [OR] 40.50; 95% CI 8.68–189.08; P < 0.001). In a multivariate logistic regression analysis, DNI was a significant independent factor for predicting AGPN after adjusting age, sex, log WBC count, log neutorphil count, log lymphocyte count, CRP concentration, and procalcitonin concentration (OR 4.32; 95% CI 1.81–10.34, P < 0.001).

Conclusions

This study showed that DNI was an effective marker to differentiate between AGPN and acute graft rejection. Thus, these finding suggest that DNI may be a useful marker in the management of these patients.

Comparison of MMF with prednisone in terms of rejection and duration of activity of transplant in rabbits that underwent retroperitoneal heterotopic heart transplantation

AIM

In this study, mycophenolate mofetil (MMF) and methylprednisolone (MP) were compared in terms of rejection and duration of activity of the transplant in New Zealand rabbits that underwent retroperitoneal heart transplantation.

METHODS

Retroperitoneal heart transplantation was performed in New Zealand white rabbits. The animals were divided into two groups. MMF group (group 1) (10 donors, 10 recipients): 12.5 mg/kg MMF was administered orally for two days prior to the surgery; MP group (group 2) (nine donors, nine recipients): 2 mg/kg MP was administered intramuscularly for two days prior to the surgery. After the operation, we waited until all motor activity in the transplanted heart had stopped. The transplant was then removed and the recipient was sacrificed. A donor in the MP group was excluded since it died before the motor activity had stopped.

RESULTS

No statistically significant difference was found between the groups in terms of rejection score (p = 0.865). However, duration of motor activity was found to be statistically significantly longer in the MMF group, compared to the MP group (p = 0.013).

CONCLUSION

In this experimental study, MMF was similar to MP in terms of rejection but had better efficacy in terms of duration of motor activity of the transplant.

The risk of cholelithiasis in patients after heart transplantation

INTRODUCTION

Extended immunosuppressive treatment in patients after heart transplantation modifies etiopathogenesis and occurrence of many diseases in this population. The aim of the present study was to evaluate the frequency and to define risk factors for cholelithiasis after heart transplantation (HTX).

MATERIAL AND METHODS

The study population consisted of 176 subjects. Of them, 24 patients (group A) presented with symptomatic cholelithiasis. Another group of 24 patients without cholelithiasis (group B) served as controls. Both groups were similar with respect to age, gender and follow-up after the transplant. Clinical interview, surgical and hospitalization data were collected from medical records.

RESULTS

The groups did not differ in demographic features. There were statistical differences (p < 0.05) between group A and B in rejection reaction, doses of immunosuppressive drugs, type 2 diabetes, serum lipid disorders and acute rejection episodes. These events were caused by modification of treatment, especially the immunosuppressive regimen. Group A consisted of 75% men and 25% women. The frequency of symptomatic cholelithiasis was 11.7% in men and 27.3% in women, on average 19.5%. Mean time to cholelithiasis following HTX was 37.9 ±4.9 (Me = 41.5) months, 27.7 ±8.2 (Me = 30.0) months in women and 41.3 ±5.9 (Me = 41.5) months in men. The female to male ratio was 2.3: 1.

CONCLUSIONS

Cholelithiasis following HTX was significantly more frequent as compared with the non-transplant population. Patients with cholelithiasis required more aggressive immunosuppression because of more frequent episodes of acute transplant rejection. Patients with cholelithiasis significantly more frequently showed increased glycemia and blood lipids, which could be the side effect of intensive immunosuppressive therapy.

Detection and grading of coronary allograft vasculopathy in children with contrast-enhanced magnetic resonance imaging of the coronary vessel wall

BACKGROUND

Coronary allograft vasculopathy is the leading cause of late death after heart transplantation in children. It is poorly detected by conventional angiography. Intravascular ultrasound is invasive and costly. This study shows that magnetic resonance imaging (MRI) late gadolinium enhancement (LGE) of the coronary vessel wall can detect and grade coronary allograft vasculopathy.

METHODS AND RESULTS

Twenty-four children (10 male; age range, 9-17 years) underwent coronary angiography, intravascular ultrasound, and MRI. Maximal intimal thickness and mean intimal index were recorded. MRI included coronary magnetic resonance angiogram and LGE vessel wall imaging with 1.5 T (n=12) and 3.0 T (n=12). Ten healthy control subjects also underwent LGE MRI. Mean time posttransplantation was 5.5 years (range, 0.25-14 years). Seven patients had Stanford grade IV coronary allograft vasculopathy on intravascular ultrasound, 3 of whom had angiographic disease. Maximal intimal thickness and mean intimal index were 0.73±0.50 mm and 20.9±10.6%, respectively. On MRI, mean diameter of enhancement of vessel wall was 6.57±4.91 mm, and mean enhancement index (indexed to vessel lumen size) was 1.10±1.72. The control group showed little or no LGE. Correlation of LGE with maximal intimal thickness using the Pearson coefficient was 0.80 (P<0.001) and with mean intimal index was 0.92 (P<0.001). An MRI diameter >7.5 mm gave 86% sensitivity and 93% specificity.

CONCLUSIONS

LGE scores correlate well with traditional intravascular ultrasound measures. These promising early results encourage larger-scale clinical studies to investigate whether LGE MRI will allow closer follow-up and better prevention of coronary allograft vasculopathy in children.

Mycophenolate mofetil (MMF) does not slow the progression of subclinical atherosclerosis in SLE over 2 years

Accelerated atherosclerosis is a major cause of mortality in SLE. Mycophenolate mofetil (MMF) has been shown to suppress growth factor-induced proliferation of vascular smooth muscle and endothelial cells in animal models. We hypothesized that MMF might modify the inflammatory component of atherosclerosis in SLE. We examined the effect of MMF on atherosclerosis as measured by changes in carotid intima-media thickness (IMT) or coronary artery calcium (CAC) over 2 years. CAC and carotid IMT were measured at baseline and 2 years later in a cohort of 187 patients with SLE. The cohort was 91% women, 59% Caucasian, and 35% African-American, with a mean age of 45 ± 11 years. Of these, 12.5% (n = 25) received MMF during follow-up. The daily dose ranged from 500 to 3,000 mg/day, and duration ranged from 84 days to the entire 2 years. We divided MMF users into three groups: low exposure (<1,500 mg average daily dose), high exposure (≥1,500 average daily dose), and any exposure of MMF (<1,500 or ≥1,500 average daily dose) for 2 years. The mean CAC increased in all four groups: no MMF: 1.17-1.28, low MMF: 1.02-1.13, high MMF: 1.44-1.61, and any MMF: 1.21-1.34 log-Agatston units. Compared to no MMF, there was no statistically different change between the three groups (p = 0.99, 0.87, and 0.91). Similarly, mean carotid IMT increased in all four groups: no MMF: 0.58-0.66, low MMF: 0.55-0.60, high MMF: 0.56-0.71, and any MMF: 0.56-0.66. We then adjusted for statin use, lupus nephritis, body mass index, systolic blood pressure, cholesterol, and age during the 2-year follow-up. The association between MMF exposure and change in CAC or carotid IMT was not statistically significant (p = 0.63 for CAC, and p = 0.085 for carotid IMT). There was no evidence that MMF slowed or decreased the progression of atherosclerosis as measured by carotid IMT or CAC. Because the number of patients taking MMF was only twenty-five, larger studies for longer time periods are needed to explore any effect of MMF on subclinical atherosclerosis in SLE.

Cordyceps sinensis extracts attenuate aortic transplant arteriosclerosis in rats

BACKGROUND

Transplant arteriosclerosis is a hallmark of chronic rejection and is still the major limiting factor affecting the success of long-term organ transplants. Development of transplant arteriosclerosis is refractory to conventional immunosuppressive drugs, and adequate therapy is not yet available. The aim of this study was to determine the role of Cordyceps sinensis extracts in reducing the formation of transplant arteriosclerosis in a rat aortic transplant model.

METHODS

Lewis rat aortic allografts were transplanted into Brown-Norway recipient rats. Recipients received 0.5, 1, 2, and 5 mg/kg of Cordyceps sinensis extracts (or control saline) daily via intragastric injection for 60 d. Grafts were harvested 60 d post-transplantation and intimal thickness determined microscopically following hematoxylin and eosin (H and E) staining and abdominal aorta protein profiles determined by Western blot analysis. Cellular localization was assessed by histology and immunohistochemistry and the serum analyzed for tumor necrosis factor alpha (TNF-α) and intercellular adhesion molecule-1 (ICAM-1) by enzyme-linked immunosorbent assay (ELISA).

RESULTS

C. sinensis administration resulted in a significant reduction in neointimal formation (neointimal thickness 8.27 ± 1.95 μm [0.5 mg/kg], 3.69 ± 1.43 μm [1 mg/kg], 3.69 ± 1.43 μm [1 mg/kg], 3.69 ± 1.43 μm [1 mg/kg] versus 11.42 ± 2.67 μm [control]) and in the proliferative activity of vascular smooth muscle cells. In addition, localized expression of TNF-α and ICAM-1 in transplant aortas was characterized by immunohistochemistry and immunoblot analyses demonstrating that C. sinensis treatment significantly reduced TNF-α and ICAM-1 levels compared with levels observed in controls (P < 0.05). Serum TNF-α and ICAM-1 levels were significantly reduced in C. sinensis-treated animals compared with controls (P < 0.05).

CONCLUSION

C. sinensis treatment effectively reduced the formation of transplant arteriosclerosis in a rat aortic transplant model.

Systemic inflammation and metabolic syndrome in cardiac allograft vasculopathy

BACKGROUND

Metabolic syndrome and elevation of inflammatory markers is common in transplant recipients. We investigated the role of insulin resistance and C-reactive protein (CRP) in predicting development of angiographic cardiac allograft vasculopathy (CAV).

METHODS

CRP and lipid profile were measured in 114 cardiac transplant recipients at 4.7 +/- 3.1 years post-transplant. A triglyceride/high-density lipoprotein cholesterol (TG/HDL) ratio of >or=3 was considered a marker of insulin resistance. Ninety-seven patients (mean age +/- SD: 48.2 +/- 16.7 years) subsequently underwent routine coronary angiography at 8.6 +/- 3.2 years post-transplantation. Diagnosis of CAV required the presence of stenosis of >or=40% in any major branch, and/or distal pruning of secondary side branches. Coronary artery stenosis >or=70% was defined as severe.

RESULTS

Eighty-one percent of patients were treated with statins. Low-density lipoprotein (LDL)-cholesterol level was 98 +/- 26 mg/dl at study entry. CRP and TG/HDL were found to be predictors of development of CAV. CAV severity correlated with TG/HDL (p < 0.005), but not with CRP level. Freedom from CAV 5 years after study entry was 9% in patients with TG/HDL >3, CRP >3 mg/liter, as compared with 65% in patients with TG/HDL <3, CRP <3 mg/liter (p = 0.003). The combination of CRP >3 mg/liter and TG/HDL >3 identified a sub-group of patients having a 2.8-fold increased odds ratio for a combined end-point of cardiovascular (CV) events (percutaneous coronary intervention, coronary artery bypass graft, left ventricular ejection fraction <45%) and death (95% confidence interval 0.90 to 8.45, p = 0.07) compared to patients with CRP <3 mg/liter and TG/HDL <3.

CONCLUSIONS

CRP >3 mg/liter and TG/HDL >3 are cumulative risk factors for angiographic CAV and the combined end-point of CV events and death in transplant patients and these patients should be targeted for intervention.

Mycophenolate Mofetil and Atherosclerosis: Results of Animal and Human Studies

The immunosuppressive agent mycophenolate mofetil (MMF) has beneficial effects in cardiac transplant patients beyond the suppression of tissue rejection. Patients with regimens containing MMF experience diminished intimal thickening and cardiac allograft vasculopathy compared to patients treated with azathioprine. Studies have shown that diet-induced atherosclerosis (a related vasculopathy) is a chronic inflammatory process, and so MMF has also been used to reduce atherosclerosis in a rabbit model of hyperlipidemia. These data hold out the intriguing possibility that MMF might be a viable primary or secondary preventive agent in people at significant risk for atherosclerosis.

Drug-induced immunomodulation to affect the development and progression of atherosclerosis: a new opportunity?

Inflammation and cytokine pathways are crucial for the development and progression of atherosclerotic lesions. In this review, the hypothesis that immunomodulatory drugs provide a possible therapeutic modality for cardiovascular disease is evaluated. Therefore, after a short overview of the specific inflammatory pathways involved in atherosclerosis, literature on the effect of several immunomodulatory drugs, such as nonsteroidal anti-inflammatory drugs, specific cyclooxygenase inhibitors and immunosuppressive drugs, used currently in the prevention of rejection after organ transplant, on the development and progression of atherosclerosis is reviewed. In addition, the pleiotropic immunomodulatory effect of two established cardiovascular drugs (angiotensin-converting enzyme inhibitors and statins) is discussed.

Mycophenolate mofetil and C-reactive protein in renal transplant recipients

BACKGROUND

C-reactive protein (CRP) is a strong predictor of cardiovascular disease, all-cause mortality, and renal allograft loss. Little is known about the effects of immunosuppressive and cardiovascular risk-modifying drugs on CRP in renal transplant recipients.

METHODS

We retrospectively identified stable patients with > or =1 highly sensitive CRP measurements between January 1 and August 31, 2005. Variables collected included patient demographics; transplant, dialysis, and cardiovascular disease-related variables; and medication profiles. Univariate correlations with CRP were assessed by unpaired Student t testing, analysis of variance, or chi analysis and followed by multivariate linear regression with stepwise backward elimination until a final stable model was attained.

RESULTS

CRP levels were obtained in 298 recipients. In univariate analysis, body mass index (P<0.0001) and systolic blood pressure (P=0.009) showed a positive correlation, whereas number of immunosuppressive drugs (P=0.05) and use of mycophenolate mofetil (MMF) (P=0.003) were negatively correlated with CRP levels. By multivariate analysis, only body mass index (P<0.0001) and MMF dose (P<0.0001) were independently and opposingly correlated with CRP. Mean CRP level was 5.18+/-5.7 mg/L in patients not taking MMF compared with 3.13+/-3.5 mg/L in those on 2000 mg per day (P=0.002).

CONCLUSIONS

MMF use correlates inversely with CRP levels in renal transplant recipients, suggesting that immunosuppressive regime design may alter allograft and cardiovascular disease risk in these patients. Prospective study of the effects of MMF on novel cardiovascular disease risk factors such as CRP is warranted.

Diagnosis of graft coronary artery disease

PURPOSE OF REVIEW

Graft coronary artery disease is the leading cardiac cause of death in patients who have undergone cardiac transplantation. Due to denervation, classic symptoms of angina are not reliable. Many transplant centers have a protocol of routine annual surveillance cardiac angiography because treatment options are limited, especially with advanced disease. Angiography is an assessment of the arterial lumen, however, and can miss nonfocal disease. This paper reviews invasive and noninvasive diagnostic tools for graft coronary artery disease. Intravascular ultrasound is the most sensitive, but the cost and lack of widespread expertise make it unpopular. Noninvasive techniques have been studied. An ideal test would be sufficiently sensitive to detect disease and allow for prognostic information. Dobutamine echocardiography is the most sensitive noninvasive test but can have a high false-positive rate. It is also not universally available. Exercise nuclear imaging is specific and can be used as a confirmatory test in patients with positive dobutamine echocardiograms.

RECENT FINDINGS

Computed tomographic imaging and cardiac magnetic resonance imaging are exciting new modalities but require further study.

SUMMARY

There is no test sensitive and specific enough yet that can be confidently used to replace coronary angiography.

Measuring patient-reported outcomes in solid organ transplant recipients: an overview of instruments developed to date

Improvements in organ preservation methods, immunosuppressive regimens and general post-transplant care have resulted in an increased life expectancy and a continually decreasing morbidity after solid organ transplantation. As attention gradually moves towards improving subjective patient outcomes, the use of patient-reported outcome measures (PROs) thus becomes increasingly important in post-transplant patient management. This paper provides a brief systematic overview of the transplant-specific PRO measures, and their psychometric properties, developed and used in solid organ transplant recipients to date. PRO measures may focus on or encompass different aspects of life relevant to organ transplant patients: overall quality of life (QOL), physical, psychological and social functioning, and adherence. Overall QOL can be measured using transplant-specific or generic QOL instruments, or a combination of both. In general, very little information is available on the psychometric properties of PRO measures, and there is no gold standard for PRO measurement. Transplant-specific and generic PRO instruments are complementary. Generic instruments will continue to be important for economic evaluations, but transplant-specific instruments may be more useful for patient management purposes, as they are generally more sensitive to small but clinically relevant changes in outcomes in transplant populations.

Vascular Remodeling 1 Year After Cardiac Transplantation

BACKGROUND

The belief that vascular remodeling and intimal hyperplasia are causes of luminal narrowing in cardiac allograft vasculopathy (CAV) is controversial. This study evaluated the relationship of vascular remodeling and intimal hyperplasia to luminal narrowing 1 year after orthotopic heart transplantation.

METHODS

Intravascular ultrasound imaging was performed on 190 cardiac transplant recipients at baseline and again 1 year after transplantation as part of a randomized trial of mycophenolate mofetil (MMF) and azathioprine (Aza). Studies 1 year apart were matched at 625 sites. All sites were classified into positive, non-significant and negative remodeling patterns, depending on a change of +/-10% in external elastic membrane area. Of the 190 patients, 99 were randomized to receive MMF, and 91 to receive Aza.

RESULTS

A total of 625 sites were observed. Of these, 52% had no remodeling, 25% exhibited vessel dilation, and 23% had vessel shrinkage in the presence of variable intimal growth (Delta intimal area: 0.73 +/- 1.70 mm2, p < 0.0001; 1.23 +/- 2.02 mm2, p < 0.0001; and 0.20 +/- 1.40 mm2, p = 0.09, respectively). Sixty percent of the lumen loss was due to a decrease in external elastic membrane area and 40% to an increase in intimal area (p = 0.005). Compared with Aza-treated patients, the MMF-treated patients had a lower incidence of vessel shrinkage (17% vs 28%, p = 0.001), and a trend for smaller maximum intimal thickness (0.21 +/- 0.25 mm vs 0.29 +/- 0.31 mm, p = 0.052).

CONCLUSIONS

Positive remodeling is associated with intimal growth, but negative remodeling does not correlate with any specific change in intimal hyperplasia. Constrictive remodeling is more responsible than intimal hyperplasia for the luminal narrowing that occurs. MMF is more efficacious than azathioprine in preventing the development of CAV at 1 year, by reducing the degree and incidence of vessel shrinkage and the progression of intimal hyperplasia.

Similar Efficacy and Safety of Enteric-coated Mycophenolate Sodium (EC-MPS, Myfortic) Compared With Mycophenolate Mofetil (MMF) in De Novo Heart Transplant Recipients: Results of a 12-Month, Single-blind, Randomized, Parallel-group, Multicenter Study

BACKGROUND

Enteric-coated mycophenolate sodium (EC-MPS, myfortic) is an advanced formulation that delays the release of mycophenolic acid (MPA). Its efficacy and safety has been proven in several clinical trials in renal transplantation.

METHODS

In a single-blind, multicenter trial, a total of 154 de novo heart transplant patients were randomized to either EC-MPS 1,080 mg twice daily or mycophenolate mofetil (MMF) 1,500 mg twice daily. Eligible patients included men or women aged 18 to 65 years, undergoing primary heart transplantation, who were treated with cyclosporine microemulsion and corticosteroids as basic immunosuppression. The primary study objective was to investigate the incidence of biopsy-proven and treated acute rejection, graft loss or death (defined as treatment failure) for EC-MPS vs MMF during the first 6 months of treatment in de novo heart transplant recipients. Secondary objectives included assessment of the overall safety and tolerability of EC-MPS vs MMF in the study population.

RESULTS

The primary efficacy variable, treatment failure at 6 months, was similar for both treatments: 52.6% for EC-MPS and 57.9% for MMF (2-sided 95% confidence interval [CI]: -21.0% to 10.4%). At 12 months, treatment failure was 57.7% for EC-MPS and 60.5% for MMF (2-sided 95% CI: -18.4 to 12.7), and death and graft loss rate was 5.1% vs 9.2% for EC-MPS and MMF at 12 months, respectively (2-sided 95% CI: -12.2 to 4.1). The overall safety profile was similar for both groups. Significantly more patients on MMF had two or more study medication dose reductions during the treatment period.

CONCLUSIONS

These 6- and 12-month results show that EC-MPS is therapeutically similar to MMF in de novo heart transplant recipients and has a comparable safety profile.

Mycophenolate mofetil reduces intimal thickness by intravascular ultrasound after heart transplant: reanalysis of the multicenter trial

The mycophenolate mofetil (MMF) trial involved 650 heart transplant patients from 28 centers who received MMF or azathioprine (AZA), both in combination with cyclosporine and corticosteroids. Baseline and 1-year intravascular ultrasound (IVUS) were performed in 196 patients (102 MMF and 94 AZA) with no differences between groups in IVUS results analyzed by morphometric analysis (average of 10 evenly spaced sites, without matching sites between studies). Baseline to first-year IVUS data can also be analyzed by site-to-site analysis (matching sites between studies), which has been reported to be more clinically relevant. Therefore, we used site-to-site analysis to reanalyze the multicenter MMF IVUS data.

RESULTS

IVUS images were reviewed and interpretable in 190 patients (99 MMF and 91 AZA) from the multicenter randomized trial. The AZA group compared to the MMF group had a larger number of patients with first-year maximal intimal thickness (MIT)>or=0.3 mm (43% vs. 23%, p=0.005), a greater decrease in the mean lumen area (p=0.02) and a decrease in the mean vessel area (the area actually increased in the MMF group, p=0.03).

CONCLUSION

MMF-treated heart transplant patients compared to AZA-treated patients, both concurrently on cyclosporine and corticosteroids, in this study have significantly less progression of first-year intimal thickening.

Indications of mycophenolate mofetil in liver transplantation

Mycophenolate mofetil (MMF) is approved for prophylaxis of acute rejection after kidney, heart, and liver transplantation as well as for pediatric patients after kidney transplantation. MMF, a noncompetitive inhibitor of inosine monophosphate dehydrogenase (IMPDH), blocks de novo purine synthesis which leads to an effective inhibition of proliferation selectively in T and B lymphocytes, smooth muscle cells, and fibroblasts. MMF shows additional effects with inhibition of the expression of activating and adhesion molecules on the surface of lymphocytes. The beneficial safety profile with distinct side effects compared to calcineurin inhibitors (CNI) enable efficacious combination with ciclosporin or tacrolimus as de novo therapy after liver transplantation. Furthermore, recent studies show the possibility to reduce CNI induced toxicities by adding MMF to primary immunosuppression. MMF is also used to enable early steroid withdrawal after liver transplantation. MMF can increase efficacy of immunosuppressive therapy and thereby support the treatment of steroid resistant acute rejections, chronic rejections and chronic graft dysfunction.

Review of Major Clinical Trials with Mycophenolate Mofetil in Cardiac Transplantation

Over the past 10 years, the addition of mycophenolate mofetil (MMF) to combination immunosuppressive regimens in cardiac transplant patients has resulted in significant outcomes benefits. Randomized trials and other studies have demonstrated that the use of MMF is associated with a decreased risk of rejection and improved survival. This article will provide an overview of these trials, as well as those evaluating MMF in renal-sparing regimens and in pediatric cardiac transplant recipients. In addition, emerging evidence demonstrating that MMF may provide long-term benefits in reducing cardiac allograft vasculopathy and those evaluating the role of MMF therapeutic drug monitoring in cardiac transplant recipients will be discussed.

Improving outcomes in heart transplantation: the potential of proliferation signal inhibitors

Graft failure and mortality among heart transplant recipients remains higher than in populations receiving renal transplants. A major cause of graft loss is cardiac allograft vasculopathy (CAV), a condition characterized by diffuse thickening of coronary blood vessels. CAV often progresses silently, with major cardiac events (eg, ventricular arrhythmia) being the first presentation. Better diagnosis and monitoring of CAV is now possible with intravascular ultrasonography, a sensitive technique for measuring intimal thickness. To date, immunosuppressants have shown little efficacy for preventing CAV. However, a new class of agents, proliferation signal inhibitors (sirolimus and everolimus), have shown considerable efficacy in this regard and for preventing rejection. In an open-label trial, sirolimus therapy was associated with less intimal and medial proliferation than azathioprine. More robust evidence is available from a larger-scale, double-blind trial involving everolimus. At 12-month follow-up the incidence of CAV was significantly lower in patients receiving everolimus (35.7% and 30.4% for everolimus 1.5 and 3.0 mg/d vs 52.8% for azathioprine; P < .05). Sirolimus and everolimus were also associated with a lower rate of cytomegalovirus infection. As with other immunosuppressants, these agents are associated with adverse events (eg, hyperlipidemia), but they can be managed. Coadministration with calcineurin inhibitors (CNIs) can exacerbate CNI-related nephrotoxicity, but evidence suggests that everolimus administered with reduced-exposure cyclosporine in the maintenance phase preserves renal function without loss of immunosuppressive efficacy. Reduced CNI dosing in de novo patients is also a potential future benefit. Proliferation signal inhibitors have considerable potential for improving outcomes in heart transplantation.

Three-year results of a randomized, double-blind, controlled trial of mycophenolate mofetil versus azathioprine in cardiac transplant recipients

BACKGROUND

This study reports the 36-month results of a randomized, double-blind, active-controlled trial of mycophenolate mofetil (MMF) vs azathioprine (AZA) in heart transplant patients.

METHODS

Patients were randomized at the time of transplant to receive MMF (1,500 mg twice a day, N = 327) or AZA (1.5 to 3 mg/kg in 4 daily doses, N = 323) in addition to cyclosporine and corticosteroids; 289 patients in each group received study drug. Data were analyzed in all randomized patients (enrolled) and in patients who received study medications (treated). Clinical and graft assessments continued for 36 months.

RESULTS

For the co-primary end-point, 53 of 289 (18.3%) AZA-treated patients either died or received another transplant compared with 34 of 289 (11.8%) MMF-treated patients (p < 0.01). Time to re-transplantation or patient death was significantly shorter for AZA- than MMF-treated patients (p = 0.029). In patients undergoing intravascular ultrasound, the change in mean maximal intimal thickness was less for the MMF group than for the AZA group (0.06 +/- 0.03 mm vs 0.13 +/- 0.03 mm, respectively; p = 0.056). No significant differences between treatments were observed in quantitative coronary angiographic measurements of transplant coronary vasculopathy. Congestive heart failure, atrial arrhythmia and leukopenia were more common in the AZA group, whereas diarrhea, esophagitis, Herpes simplex, Herpes zoster and cytomegalovirus (CMV) tissue invasion were more common in MMF-treated patients.

CONCLUSION

MMF reduces mortality and graft loss up to 36 months after transplantation.

Neointimal Inflammation and Adventitial Angiogenesis Correlate With Severity of Cardiac Allograft Vasculopathy in Pediatric Recipients

BACKGROUND

Chronic inflammation and angiogenesis have been implicated in the pathogenesis of both cardiac allograft vasculopathy (CAV) and age-related vasculopathy. Because concurrent atherosclerosis does not complicate assessment of CAV in children, we sought to characterize the spectrum of coronary lesions in this population and determine whether inflammatory infiltrates and angiogenesis correlate with severity of CAV.

METHODS

In 18 pediatric heart specimens CAV was graded 1 to 4 (none to severe). Each case was assigned to either: Group I, no inflammation; Group II, perivascular inflammation; or Group III, perivascular and neointimal inflammation. Inflammatory infiltrates were immunophenotyped using anti-CD3, anti-CD20 and HAM 56. Angiogenesis was assessed by determining microvascular density (MVD) in 5 high-power fields (HPFs) per section.

RESULTS

CAV was evident in 94% of cases, and inflammation in 61%. Cases with neointimal inflammation had significantly more severe CAV compared with cases without inflammation (2.7 +/- 0.16 vs 1.9 +/- 0.2, p = 0.002). MVD was significantly higher in both inflammation groups (Groups II and III) compared with Group I (4.1 +/- 0.5 per HPF and 5.9 +/- 0.5 vs 3.1 +/- 0.7, p = 0.018 and p = 0.002) and correlated with the degree of CAV (p = 0.007). The perivascular infiltrates (Group II, n = 5) contained lymphocytes, macrophages and plasma cells, and 67% of neointimal infiltrates (Group III, n = 6) also contained eosinophils.

CONCLUSIONS

CAV in children is more common than previously reported. Our data indicate that CAV is often associated with inflammation and that adventitial angiogenesis correlated with the severity of CAV.

Clinical experience with Certican (everolimus) in maintenance heart transplant patients at the Medical University of Vienna

Innovations in immunosuppressant therapy often transfer from renal transplantation to heart transplantation. Accordingly, there is growing interest in calcineurin inhibitor (CNI)- and steroid-sparing regimens for heart transplant patients. The novel proliferation signal inhibitor, Certican (everolimus), has been shown to allow reduced CNI exposure in renal transplant recipients without loss of efficacy. It has also demonstrated efficacy for reducing biopsy-proven acute rejection (BPAR) and cardiac allograft vasculopathy (CAV) in de novo heart transplantation. The present study reports early clinical experience of introducing everolimus as maintenance immunosuppression in heart transplant recipients whose previous regimen had failed. A 58-year-old woman received an organ from a 56-year-old female donor. She was prescribed cyclosporine for micromemulsion (CsA; Neoral), azathioprine, prednisolone and atorvastatin. After 3 months, azathioprine was switched to mycophenolate mofetil (MMF). At Month 27, the patient experienced Grade 3A BPAR, had a left ventricular ejection fraction (LVEF) of 20%, and compromised renal function. After steroid boluses to control BPAR, everolimus 3.0 mg/day was prescribed, while CsA and prednisolone doses were reduced. One month later, the patient contracted herpes labialis and pneumonia, and creatinine was elevated; CsA was stopped, everolimus dose was reduced to 1.5 mg/day and prednisolone reduced further. After another month, LVEF recovered to 50% and creatinine was 1.29 mg/dl. There was evidence of hyperlipidemia, which responded to atorvastatin 10 mg. For maintenance immunosuppression after heart transplantation, everolimus may allow CsA dose reduction and could be efficacious in combination with MMF. Further studies are required to confirm its efficacy and effects on CAV.

Clinical Experience With Certican® (Everolimus) in De Novo Heart Transplant Patients at the Deutsches Herzzentrum Berlin

Immunosuppressant agents have greatly increased graft and overall survival in heart transplant patients, but some of these agents (e.g., calcineurin inhibitors [CNI] and corticosteroids) can also induce adverse events that may contribute to cardiac allograft vasculopathy (CAV) (e.g., nephrotoxicity and cytomegalovirus infection). The current trend is therefore toward CNI- and steroid-sparing regimes. This study reports on the initial clinical experience with Certican (everolimus), a novel proliferation signal inhibitor with immunosuppressant properties that has been shown to prevent or delay CAV. Seven de novo heart transplant patients were treated at our center. Patients received cyclosporine for microemulsion (CsA; Neoral), corticosteroids and fluvastatin in addition to everolimus. Mean everolimus blood trough levels were maintained within the target range of 3 to 8 ng/ml throughout the first 14 weeks post-transplant. CsA was initiated at a reduced dose, and by Weeks 8 to 14 the mean trough blood level was 187.7 ng/ml. The combination of everolimus and reduced-dose CsA was not associated with increased incidence of biopsy-proven acute rejection (BPAR). Two patients did experience BPAR, but only very mildly (ISHLT Grade 1A). The mean creatinine level pre-transplant was 1.5 mg/dl; this increased to 2.0 mg/dl at 2 weeks post-transplant, but returned to near baseline levels during Weeks 8 to 14 (1.66 mg/dl). Some patients had elevated blood lipids. Patients receiving everolimus should have lipid levels monitored on a regular basis. Everolimus may allow optimization of immunosuppressant regimens in de novo heart transplant patients so that adequate efficacy can be achieved with reduced CNI exposure, thereby protecting kidney function.

Advancing Immunosuppression Therapy to Counter the Progression of Cardiac Allograft Vasculopathy

BACKGROUND

Cardiac allograft vasculopathy (CAV) is the major cause of late mortality in heart transplant recipients. Because immunosuppressive therapy has been convincingly shown to suppress cellular rejection and prolong cardiac allograft survival, we assessed the efficacy of advancing immunosuppressive therapy in reversing or delaying CAV by switching azathioprine to combination mycophenolate mofetil and prednisone (MMF-P).

METHODS AND RESULTS

Seventeen adult posttransplant patients, whose CAV was prospectively approached with the MMF-P protocol, were studied. The development of significant CAV was declared on the index coronary angiogram and the MMF-P protocol was instituted. The degree of occlusion for all coronary lesions was quantitated for the index angiogram, and for the angiograms performed 1 year before (baseline) the index angiogram and annually for 2 years after the index angiogram (MMF-P years 1 and 2). There was a significant change in percent occlusion over time (P < .001). Percent occlusion increased significantly from the baseline year to the index CAV year, but then decreased significantly from the index CAV year to the MMF-P treatment years 1 and 2.

CONCLUSION

Advancing immunosuppression with MMF-P can delay the progression of and partially reverse lumen narrowing of CAV in heart transplant recipients.