Proliferation signal inhibitor toxicities after thoracic transplantation

Everolimus Based Immunosuppression Strategies in Adult Lung Transplant Recipients: Calcineurin Inhibitor Minimization Versus Calcineurin Inhibitor Elimination

Everolimus (EVE) provides an alternative to maintenance immunosuppression when conventional immunosuppression cannot be tolerated. EVE can be utilized with a calcineurin inhibitor (CNI) minimization or elimination strategy. To date, clinical studies investigating EVE after lung transplant (LTx) have primarily focused on the minimization strategy to preserve renal function. The primary aim was to determine the preferred method of EVE utilization for lung transplant recipients (LTR). To undertake this aim, we compared the safety and efficacy outcomes of EVE as part of minimization and elimination immunosuppressant regimens. Single center retrospective study of 217 LTR initiated on EVE (120 CNI minimization and 97 CNI elimination). Survival outcomes were calculated from the date of EVE commencement. On multivariate analysis, LTR who received EVE as part of the CNI elimination strategy had poorer survival outcomes compared to the CNI minimization strategy [HR 1.61, 95% CI: 1.11-2.32, p=0.010]. Utilization of EVE for renal preservation was associated with improved survival compared to other indications [HR 0.64, 95% CI: 0.42-0.97, p=0.032]. EVE can be successfully utilized for maintenance immunosuppression post LTx, particularly for renal preservation. However, immunosuppressive regimens containing low dose CNI had superior survival outcomes, highlighting the importance of retaining a CNI wherever possible.

Rescue Everolimus Post Lung Transplantation is Not Associated With an Increased Incidence of CLAD or CLAD-Related Mortality

Everolimus (EVE) has been used as a calcineurin inhibitor (CNI) minimization/ elimination agent or to augment immunosuppression in lung transplant recipients (LTR) with CNI-induced nephrotoxicity or neurotoxicity. The long-term evidence for survival and progression to chronic lung allograft dysfunction (CLAD) is lacking. The primary aim was to compare survival outcomes of LTR starting EVE-based immunosuppression with those remaining on CNI-based regimens. The secondary outcomes being time to CLAD, incidence of CLAD and the emergence of obstructive (BOS) or restrictive (RAS) phenotypes. Single center retrospective study of 91 LTR starting EVE-based immunosuppression matched 1:1 with LTR remaining on CNI-based immunosuppression. On multivariate analysis, compared to those remaining on CNI-based immunosuppression, starting EVE was not associated with poorer survival [HR 1.04, 95% CI: 0.67-1.61, p = 0.853], or a statistically significant faster time to CLAD [HR 1.34, 95% CI: 0.87-2.04, p = 0.182]. There was no difference in the emergence of CLAD (EVE, [n = 57, 62.6%] vs. CNI-based [n = 52, 57.1%], p = 0.41), or the incidence of BOS (p = 0.60) or RAS (p = 0.16) between the two groups. Introduction of EVE-based immunosuppression does not increase the risk of death or accelerate the progression to CLAD compared to CNI-based immunosuppression.

Everolimus Use in Lung Transplant Recipients

BACKGROUND

Most lung transplantation centers prefer triple immunosuppressive therapy with tacrolimus, mycophenolate mofetil, and corticosteroids. However, to prevent complications and comorbidities caused by tacrolimus, replacing the drug with everolimus has been considered.

METHODS

This is a retrospective observational study investigating everolimus switch for different reasons. The population was divided into 3 groups: chronic lung allograft dysfunction (CLAD), kidney impairment, and malignant neoplasm groups. We investigated whether we achieved the goal of the switch and the frequency of rejection, cytomegalovirus and fungal infections, and everolimus adverse effects.

RESULTS

Nineteen patients received everolimus therapy, and 5 of these were for CLAD, 7 for tacrolimus nephrotoxicity, and 7 for explant/de novo malignant neoplasm. The patients were followed up for a mean (SD) of 30 (16.7) months under the therapy. The number of acute cellular rejection, cytomegalovirus infection, and aspergillosis infection cases before switch were 7, 13, and 2, respectively, and 7, 2, and 3 after that. The mean values of creatinine and estimated glomerular filtration rate of the whole population after the switch improved with no statistical significance, whereas it was significant in tacrolimus nephrotoxicity group. Three patients in the CLAD group remained stable after switching, whereas 2 progressed. Only 1 of the 7 patients with malignant neoplasms had a recurrence during 31.1 (16.5) months of median follow-up. Eleven cases of everolimus adverse effects occurred in 9 patients (47.3%), with 2 (10.5%) withdrawal events. Kidney impairment (P = .02) and age (P = .05) stood out as significant risk factors for drug adverse effects.

CONCLUSIONS

After lung transplant, everolimus can be a safe alternative for immunosuppression with acceptable adverse effects.

Twelve-month effects of everolimus on renal and lung function in lung transplantation: differences in chronic lung allograft dysfunction phenotypes

Background:

Chronic lung allograft dysfunction (CLAD), a complication affecting the survival of lung transplanted patients, includes two clinical phenotypes: bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). Everolimus is used in CLAD because of its antiproliferative mechanism. In lung transplant patients treated with everolimus, the clinical course of renal and lung function has not yet been assessed systematically in CLAD, BOS and RAS patients for more than 6 months.

Methods:

We retrospectively evaluated the 12-month follow-up of renal and lung function of lung-transplanted patients switched to everolimus and evaluated the reduction in immunosuppressant dosage (ISD) and mortality. Subgroups were based on indication for everolimus treatment: CLAD and non-CLAD patients, BOS and RAS among CLAD patients.

Results:

We included 26 patients, 17 with CLAD (10 BOS, seven RAS). After 1 year from the everolimus switch, we observed renal function improvement (serum creatinine −17%, estimated glomerular filtration rate +24%) and stable pulmonary function [forced expiratory volume in the first second (FEV₁) −0.5%, forced vital capacity (FVC) +0.05%]. RAS patients had progressive functional loss, whereas BOS patients had FEV₁ improvement and FVC stability. All-cause mortality was higher in the CLAD versus non-CLAD group (41% versus 11%), without differences between BOS and RAS patients (p > 0.05). All patients had significant and persistent ISD reduction.

Conclusion:

Lung transplant patients treated with everolimus had improvements in renal function and reduced ISD. We observed sustained improvements in lung function for CLAD related to BOS subgroup results, whereas RAS confirmed the 1-year worsening functional trend. Data seem to suggest one more piece of the puzzle in CLAD phenotyping.

Modulation of Immunologic Response by Preventive Everolimus Application in a Rat CPB Model

Everolimus (EVL) is widely used in solid organ transplantation. It is known to have antiproliferative and immunosuppressive abilities via inhibition of the mTOR pathway. Preventive EVL administration may lower inflammation induced by cardiopulmonary bypass (CPB) and reduce systemic inflammatory response syndrome (SIRS). After oral loading with EVL 2.5 mg/kg/day (n = 11) or placebo (n = 11) for seven consecutive days, male Wistar rats (400-500 g) were connected to a miniaturised heart-lung-machine performing a deep hypothermic circulatory arrest protocol. White blood cells (WBC) were significantly reduced in EVL-pretreated animals before start of CPB with a preserved reduction by trend at all other time points. Ischemia/reperfusion led to decreased glucose levels. Application of EVL significantly increased glucose levels after reperfusion. In addition, potassium levels were significantly lower in EVL-treated animals at the end of reperfusion. Immunoblotting revealed increased S6 levels after CPB. EVL decreased phosphorylation of S6 in the heart and kidney, which indicates an inhibition of mTOR pathway. Moreover, EVL significantly modified phosphorylation of AKT, while decreasing IL2, IL6, RANTES, and TNFα (n = 6). Preventive application of EVL may modulate inflammation by inhibition of mammalian target of rapamycin (mTOR) pathway and reduction of proinflammatory cytokines. This may be beneficial to evade SIRS-related morbidities after CPB.

Design and rationale of the HITTS randomized controlled trial: Effect of High-intensity Interval Training in de novo Heart Transplant Recipients in Scandinavia

There is no consensus on how, when, and at what intensity exercise should be performed and organized after heart transplantation (HTx). Most rehabilitation programs are conducted in HTx centers, which might be impractical and costly. We have recently shown that high-intensity interval training (HIT) is safe, well tolerated, and efficacious in maintenance HTx recipients, but there are no studies among de novo patients, and whether HIT is feasible and superior to moderate training in HTx recipients is unclear. A total of 120 clinically stable HTx recipients older than 18 years will be recruited from 3 Scandinavian HTx centers. Participants are randomized to HIT or moderate training, shortly after surgery. All exercises are supervised in the patients' local communities. Testing at baseline and follow-up includes the following: VO2peak (primary end point), muscle strength, body composition, quality of life, myocardial performance, endothelial function, biomarkers, and progression of cardiac allograft vasculopathy. A subgroup (n = 90) will also be tested at 3-year follow-up to assess long-term effects of exercise. So far, the HIT intervention is well tolerated, without any serious adverse events. We aim to test whether decentralized HIT is feasible, safe, and superior to moderate training, and whether it will lead to significant improvement in exercise capacity and less long-term complications.

Influence of proliferation signal inhibitors on vascular endothelial growth factor production in heart transplant recipients - preliminary report

Proliferation signal inhibitors (PSI) are especially beneficial for heart transplant recipients, but are rarely used due to frequent side effects. As they may be caused by vascular endothelial growth factor (VEGF), we performed a prospective cross-sectional pilot study to assess the influence of PSI and/or calcineurin inhibitors (CNI) presence in immunosuppressive protocols of heart transplant recipients on VEGF secretion. All electively screened heart transplant recipients willing to participate were enrolled in the study. The preliminary report was based on the results of the first 89 serum samples. The study group (n = 84) consisted of the PSI group (n = 14) further divided into the PSI + CNI subgroup (n = 10) and PSIw/oCNI subgroup (n = 4) based on concomitant CNI use, and the CNIw/oPSI group (n = 70) receiving CNI without PSI. The control group (n = 5) consisted of patients not requiring immunosuppression. VEGF was present in serum of 70 (83%) study group patients: median (range) 18 (0-316) pg/mL, mean 35 ± 57 pg/mL; in 13 (93%) PSI group patients: 22 (0-110) pg/mL, 28 ± 28 pg/mL, with 19 (8-20) pg/mL, 16 ± 6 pg/mL in the PSI + CNI subgroup, and 29 (0-110) pg/mL, 32 ± 32 pg/mL in the PSIw/oCNI subgroup. In the CNIw/oPSI group VEGF was present in 57 (81%) patients: 16 (0-316) pg/mL, 37 ± 62 pg/mL, and in the control group in 3 (60%) patients: 4 (0-110) pg/mL, 32 ± 48 pg/mL. None of the differences observed between any compared groups and/or subgroups was significant (χ² and Mann-Whitney U test). In conclusion, differences of VEGF concentration observed among groups imply the influence of PSI and CNI on VEGF production, but further studies involving higher numbers of participants are needed to prove it.