Study protocol: a pilot study to determine the safety and efficacy of induction-therapy, de novo MPA and delayed mTOR-inhibition in liver transplant recipients with impaired renal function. PATRON-study

Evidence-based medicine in daily surgical decision making: a survey-based comparison between the UK and Germany

BACKGROUND

Evidence-based medicine (EbM) is a vital part of reasonable and conclusive decision making for clinicians in daily clinical work. To analyze the knowledge and the attitude of surgeons towards EbM, a survey was performed in the UK and Germany.

METHODS

A web-based questionnaire was distributed via mailing lists from the Royal College of Surgeons of England (RCSE) and the Berufsverband Deutscher Chirurgen (BDC). Our primary aim was to get information about knowledge of EbM amongst German and British surgeons.

RESULTS

A total of 549 individuals opened the questionnaire, but only 198 questionnaires were complete and valid for analysis. In total, 40,000 recipients were approached via the mailing lists of the BDC and RCSE. The response rate was equally low in both countries. On a scale from 1 (unimportant) to 10 (very important), all participants rated EbM as very important for daily clinical decision making (7.3 ± 1.9) as well as for patients (7.8 ± 1.9) and the national health system (7.8 ± 1.9). On a scale from 1 (unimportant) to 5 (very important), systematic reviews (4.6 ± 0.6) and randomized controlled trials (4.6 ± 0.6) were identified as the highest levels of study designs to enhance evidence in medicine. British surgeons considered EbM to be more important in daily clinical work when compared to data from German surgeons (7.9 ± 1.6 vs. 6.7 ± 2.1, p < 0.001). Subgroup analysis showed different results in some categories; however, a pattern to explain the differences was not evident. Personal requirements expressed in a free text field emphasized the results and reflected concerns such as broad unwillingness and lack of interdisciplinary approaches for patients (n = 59: 25 in the UK and 34 in Germany).

CONCLUSION

The overall results show that EbM is believed to be important by surgeons in the UK and Germany. However, perception of EbM in the respective health system (UK vs. Germany) may be different. Nonetheless, EbM is an important tool to navigate through daily clinical problems although a discrepancy between the knowledge of theoretical abstract terms and difficulties in implementing EbM in daily clinical work has been detected. The provision of infrastructure, courses and structured education as a permanent instrument will advance the knowledge, application and improvement of EbM in the future.

Overview of the indications and contraindications for liver transplantation

Liver transplantation is the only definitive treatment option for patients with irrevocable acute or chronic liver failure. In the last four decades, liver transplantation has developed from an experimental approach with a very high mortality to an almost routine procedure with good short- and long-term survival rates. Here, we present an up-to-date overview of the indications and contraindications for liver transplantation. It is shown how the evaluation of a candidate and finally listing for transplantation has to be performed in a multidisciplinary setting. Meticulous listing, timing, and organ allocation are the crucial factors to achieve an optimal outcome for the individual patient on the one hand, and reasonably using the limited deceased donor pool on the other hand. Living-donor liver transplantation is demanding but necessarily increasing. Because patients after liver transplantation need lifelong aftercare, it is important for primary care clinicians to understand the basic medical problems and risks.

Induction immunosuppression in liver transplantation: a review

Antibody therapy for induction is seldom used in liver transplantation in the United States, but continues to be used in approximately 10% of patients. The most commonly used antibody at the current time is basiliximab (Simulect, Novartis) and is used in adults with renal dysfunction at the time of liver transplantation with the intention of delaying introduction of calcineurin-inhibitors. In children, the same antibody is commonly used in order to reduce rates of acute rejection. Most patients, adult and pediatric, are treated with initially higher levels of tacrolimus rather than antibody induction.

Calcineurin inhibitors in liver transplantation - still champions or threatened by serious competitors?

Current strategies for immunosuppression in liver transplant (LT) recipients include the design of protocols targeting a more individualized approach to reduce risk factors such as renal failure, cardiovascular complications and malignancies. Renal injury in LT recipients may be often multifactorial and is associated with increased risk of post-transplant morbidity and mortality. The quest for low toxicity immunosuppressive regimens has been challenging and resulted in CNI minimization protocols or CNI withdrawal and conversion to mycophenolate mofetil (MMF) and/or mammalian target of rapamycin inhibitor-based immunosuppressive regimens. Use of antibody induction to delay CNI administration may be an option in particular in immunocompromized, critically ill patients with high MELD scores. Protocols including MMF introduction and concomitant CNI minimization have the potential to recover renal function even in the medium and long term after LT. We review on hot topics in the prevention and management of acute and chronic renal injury in LT patients. For this purpose, we present and critically discuss results from immunosuppressive studies published in the current literature or presented at recent LT meetings.

Present state of immunosuppressive therapy in liver transplant recipients

1. Our increasing understanding of the signaling pathways and cellular interactions in transplant immunobiology has facilitated targeted strategies using novel immunosuppressive agents. 2. The pattern of immunosuppressive drug use in the United States continues to change, and the changes include the use of antibody induction therapy and the agents used in maintenance therapy. 3. The driving forces behind the development of new immunosuppressive regimens are the long-term complications of current immunosuppressive regimens (particularly renal dysfunction and metabolic disturbances).

Neuroprotective, immunosuppressant and antineoplastic properties of mTOR inhibitors: current and emerging therapeutic options

The acronym mTOR defines a family of serine-threonine protein kinase called mammalian target of rapamycin. The major role of these kinases in the cell is to merge extracellular instructions with information about cellular metabolic resources and to control the rate of anabolic and catabolic processes accordingly. In mammalian cells mTOR is present in two distinct heteromeric protein complexes commonly referred to as mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), involved in the control of a wide variety of cellular processes. It has been recently reported that compounds acting modulating mTOR activity, beside mediating the well recognized processes exploited in the anticancer and immunosuppressant effects, are provided with neuroprotective properties. In fact, mTOR is involved in the mechanism of PI3K/Akt-induced upregulation of glutamate transporter 1, GLT1, that is linked to several neuronal disorders such as stroke, Alzheimer's disease, and amyotrophic lateral sclerosis. Furthermore, in adult brain mTOR is crucial for numerous physiological processes such as synaptic plasticity, learning, memory, and brain control of food uptake. Moreover, the activation of mTOR pathway is involved in neuronal development, dendrite development and spine morphogenesis.

Indications and effectiveness of the mammalian target of rapamycin in liver transplantation

BACKGROUND

The mammalian target of rapamycin (mTOR) inhibitors are new immunosuppressive drugs for organ transplantation. They are interesting for liver transplantation because of their absence of nephrotoxicity and potential antitumor effects, because calcineurin inhibitors (CNI) are associated with renal dysfunction post-CNI and tumors. We sought to analyze the indications, safety, and efficacy of mTOR among liver transplant patients at our center.

METHODS

We retrospectively identified patients who were treated with mTOR for their indications for liver transplantation, type of immunosuppressive therapy, acute rejection episodes, and evolution of kidney function.

RESULTS

We identified 43 (19.02%) patients treated with mTOR including 35 (81.4%) males and 8 (18.6%) females of overall average age of 56.7 (range, 44-68). In 30% of patients, the drug was introduced for kidney failure, and in 23% for actual or a high risk of hepatocellular carcinoma (HCC) recurrence. The average time to introduction of the mTOR was 6.4 months (range, 1-46). The final immunosuppressive regimen was mTOR alone (73%), or mTOR plus CNI (23%), or mTOR plus mycophenolate mofetil (4%). The average values of creatinine and urea were lower after conversion to mTOR (P < .05) with a 6.9% incidence of acute rejection episodes.

CONCLUSION

The mTOR immunosuppressive drugs are safe for liver transplant patients, effectively controlling renal dysfunction. They can be used in other indications, such as neurotoxicity, de novo tumors, and high risk of HCC recurrence. More studies are needed to clarify their long-term effectiveness.

Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)

BACKGROUND

Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.

METHODS

Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).

DISCUSSION

If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.