Everolimus in different combinations as maintenance immunosuppressive therapy in heart transplant recipients

Predictors of Improvement in Renal Function After Heart Transplant

OBJECTIVES

Moderate chronic renal insufficiency is often found in patients evaluated for heart transplant. Recovery of cardiac output after heart transplant might lead to improvement of renal function. In this study, our aim was to identify predictors of improvement of renal function after heart transplant.

MATERIALS AND METHODS

Our study included a cohort of heart transplant patients treated from 2011 to 2016 whose main outcome was improved renal function, defined as glomerular filtration rate at 6 months after heart transplant of ≥ 10% compared with baseline (before transplant). Univariate and multivariate logistic regression was used to identify independent predictors.

RESULTS

Our study included 83 patients, with 29% having improvement in renal function. Multivariate analyses identified baseline glomerular filtration rate (odds ratio of 0.95; 95% confidence interval, 0.93-0.98; P = .005), absence of hypertension (odds ratio of 4.94; 95% confidence interval, 1.37-17.8; P = .015), and elective heart transplant (odds ratio of 13.71; 95% confidence interval, 1.33-141; P = .028) as independent predictors. A scale developed with independent predictors showed good accuracy (area under the curve of 0.76). The probability for improvement in renal function was 7%, 23%, and 58% in patients with low, medium, and high scores, respectively (P < .001).

CONCLUSIONS

In patients with heart transplant, baseline glomerular filtration rate, absence of hypertension, and elective heart transplant were independent predictors of improvement in renal function after heart transplant.

Targeted and global pharmacometabolomics in everolimus-based immunosuppression: association of co-medication and lysophosphatidylcholines with dose requirement

INTRODUCTION

The immunosuppressive therapy with everolimus (ERL) after heart transplantation is characterized by a narrow therapeutic window and a substantial variability in dose requirement. Factors explaining this variability are largely unknown.

OBJECTIVES

Our aim was to evaluate factors affecting ERL metabolism and to identify novel metabolites associated with the individual ERL dose requirement to elucidate mechanisms underlying ERL dose response variability.

METHOD

We used liquid chromatography coupled with mass spectrometry for quantification of ERL metabolites in 41 heart transplant patients and evaluated the effect of clinical and genetic factors on ERL pharmacokinetics. Non-targeted plasma metabolic profiling by ultra-performance liquid chromatography and high resolution quadrupole-time-of-flight mass spectrometry was used to identify novel metabolites associated with ERL dose requirement.

RESULTS

The determination of ERL metabolites revealed differences in metabolite patterns that were independent from clinical or genetic factors. Whereas higher ERL dose requirement was associated with co-administration of sodium-mycophenolic acid and the CYP3A5 expressor genotype, lower dose was required for patients receiving vitamin K antagonists. Global metabolic profiling revealed several novel metabolites associated with ERL dose requirement. One of them was identified as lysophosphatidylcholine (lysoPC) (16:0/0:0). Subsequent targeted analysis revealed that high levels of several lysoPCs were significantly associated with higher ERL dose requirement.

CONCLUSION

For the first time, this study describes distinct ERL metabolite patterns in heart transplant patients and detected potentially new drug-drug interactions. The global metabolic profiling facilitated the discovery of novel metabolites associated with ERL dose requirement that might represent new clinically valuable biomarkers to guide ERL therapy.

Effect of everolimus on the immunomodulation of the human neutrophil inflammatory response and activation

The primary cause of mortality at 5 years following a cardiac transplantation is the development of atherosclerosis, termed coronary allograft vasculopathy (CAV). This pathology is characterized by diffused intimal hyperplasia and emanates from coronary arterial injuries caused by immune inflammatory cells. Neutrophils play an important role in this inflammatory process; however, their potential participation in the pathogenesis of CAV is poorly understood. Despite their essential contribution to the prevention of graft rejection, immunosuppressive drugs could have detrimental effects owing to their pro-inflammatory activities. Thus, we investigated the impact of different immunosuppressive drugs on the inflammatory response of neutrophils isolated from the blood of healthy volunteers. Under basal conditions, mammalian target of rapamycin (mTOR) inhibitors (sirolimus and everolimus) had the most potent anti-inflammatory effect, decreasing both IL-8 release (≈−80%) and vascular endothelial growth factor (VEGF) release (≈−65%) and preserving the release of the anti-inflammatory cytokine interleukin-1 receptor antagonist (IL-1RA). In TNF-α-treated neutrophils, pre-incubation with everolimus provided the most potent effect, simultaneously reducing the release of both VEGF and IL-8 while doubling the release of IL-1RA. This latter effect of everolimus was maintained even when administered in combination with other immunosuppressive drugs. Sirolimus and everolimus decreased the tumor necrosis factor (TNF)-α-induced adhesion of neutrophils to human endothelial cells and human extracellular matrix. This effect was largely dependent on the ability of these compounds to alter β₂-integrin/CD18 activation. Our results suggest a potential mechanism for the beneficial effect of everolimus in the prevention of CAV in heart transplant recipients.