Using a weaning immunosuppression protocol in liver transplantation recipients with hepatocellular carcinoma: a compromise between the risk of recurrence and the risk of rejection?

Immunosuppression protocols for emerging oncological indications in liver transplantation: A systematic review and pooled analysis

The evolving field of liver transplant (LT) oncology calls for tailored immunosuppression protocols to minimize the risk of tumor recurrence. We systematically reviewed the available evidence from inception to May 2023 regarding immunosuppression protocols used in patients undergoing LT for cholangiocarcinoma, neuroendocrine tumors (NET), hepatic-endothelial hemangioendothelioma, and colorectal liver metastases (CRLM) to identify common practices and to evaluate their association with oncological outcomes. Studies not involving humans, case reports, and short case series (ie, n < 10) were excluded. Among 3374 screened references, we included 117 studies involving 6797 patients distributed as follows: cholangiocarcinoma (58.1%), NETs (18.8%), hepatic-endothelial hemangioendothelioma (7.7%), CRLM (6.8%), mixed neoplasms (6.8%), or others (1.7%). Only 41% of the studies disclosed details of the immunosuppression protocol, and 20.8% of studies provided drug trough concentrations during follow-up. The immunosuppression protocols described were heterogeneous and broadly mirrored routine practices for nontumoral indications. The only exception was CRLM, where tacrolimus minimization-or even withdrawal-in combination with inhibitors of the mammalian target of rapamycin (mTORi) were consistently reported. None of the studies evaluated the relationship between the immunosuppression protocol and oncological outcomes. In conclusion, based on low-quality and indirect scientific evidence, patients with tumoral indications for LT should receive the lowest tacrolimus level tolerated under close surveillance. The combination with mTORi titrated to achieve the top therapeutic range of trough concentrations could allow complete tacrolimus withdrawal. This approach may be particularly useful in patients with cholangiocarcinoma and CRLM, in whom tumor recurrence is the main cause of death. We propose a tool for reporting immunosuppression protocols, which could be implemented in future transplant oncology studies.

Challenges in Liver Transplantation for Hepatocellular Carcinoma: A Review of Current Controversies

Liver transplantation (LT) remains one of the most effective treatments for hepatocellular carcinoma (HCC) and significantly enhances patient survival. However, the application of LT for HCC faces challenges owing to advancements in cancer-specific treatment modalities and the increased burden of patients' comorbidities. This narrative review explores current controversies and advancements in LT for HCC. Key areas of focus include the management of comorbidities and patient education by advanced practice nurses, impacts of frailty on waitlists and post-LT outcomes, selection criteria for LT in the era of new downstaging tools, role of radiology in patient selection, and implications of potential immunotherapy use both before and after LT. Additionally, the importance of immunosuppression management with strategies aimed at minimizing rejection while considering the risk of HCC recurrence and the role of surveillance for HCC recurrence is highlighted. This review also underscores the importance of a multidisciplinary approach for optimizing outcomes in patients with HCC undergoing LT.

Basics and Art of Immunosuppression in Liver Transplantation

Liver transplantation is one of the most challenging areas in the medical field. Despite that, it has already been established as a standard treatment option, especially in decompensated cirrhosis and selected cases of hepatocellular carcinoma and acute liver failure. Complications due to graft rejection, including mortality and morbidity, have greatly improved over time due to better immunosuppressive agents and management protocols. Currently, immunosuppression in liver transplant patients makes use of the best possible combinations of effective agents to achieve optimal immunosuppression for long-term graft survival. Induction agents are no longer used routinely, and the aim is to provide minimal immunosuppression in the maintenance phase. Currently available immunosuppressive agents are mainly classified as biological and pharmacological agents. Though the protocols may vary among the centers and over time, the basics of effective use usually remain similar. Most protocols use the combination of multiple agents with different mechanisms of action to reduce the dose and minimize the side effects. Along with the improvement in operative and perioperative techniques, this art of immunosuppression has contributed to the recent progress made in the outcomes of liver transplants. In this review, we will discuss the various types of immunosuppressive agents currently in use, the different protocols of immunosuppression used, and the art of optimal use for achieving maximum immunosuppression without increasing toxicity. We will also discuss the practical aspects of various immunosuppression regimens, including drug monitoring, and briefly discuss the concepts of immunosuppression minimization and withdrawal.

Liver Transplantation from a Human Leukocyte Antigen-Matched Sibling Donor: Effectiveness of Direct-Acting Antiviral Therapy against Hepatitis C Virus Infection

Through living-donor liver transplantation (LDLT) from a human leukocyte antigen (HLA)-matched sibling donor, it may be possible to stop the use of immunosuppressants. It is possible that acute antibody-mediated rejection and chronic active antibody-mediated rejection through the positivity of donor-specific anti-HLA antibodies and/or T cell-mediated rejection may affect the prognosis of liver transplantation. The etiologies of liver diseases of the recipient may also affect the post-transplantation course. Herein, we report on the successful re-treatment with direct-acting antiviral (DAA) therapy against hepatitis C virus (HCV) infection in a patient who underwent a LDLT from HLA-matched sibling donor. After liver transplantation for HCV-related liver diseases, it is easy for HCV to re-infect the graft liver under a lack of immunosuppressants. DAA therapy against HCV re-infection immediately after transplantation should be commenced, and it is important to eradicate HCV for better prognosis of the recipients in LDLT for HCV-related liver diseases.

Mitochondria and Cancer Recurrence after Liver Transplantation—What Is the Benefit of Machine Perfusion?

Tumor recurrence after liver transplantation has been linked to multiple factors, including the recipient’s tumor burden, donor factors, and ischemia-reperfusion injury (IRI). The increasing number of livers accepted from extended criteria donors has forced the transplant community to push the development of dynamic perfusion strategies. The reason behind this progress is the urgent need to reduce the clinical consequences of IRI. Two concepts appear most beneficial and include either the avoidance of ischemia, e.g., the replacement of cold storage by machine perfusion, or secondly, an endischemic organ improvement through perfusion in the recipient center prior to implantation. While several concepts, including normothermic perfusion, were found to reduce recipient transaminase levels and early allograft dysfunction, hypothermic oxygenated perfusion also reduced IRI-associated post-transplant complications and costs. With the impact on mitochondrial injury and subsequent less IRI-inflammation, this endischemic perfusion was also found to reduce the recurrence of hepatocellular carcinoma after liver transplantation. Firstly, this article highlights the contributing factors to tumor recurrence, including the surgical and medical tissue trauma and underlying mechanisms of IRI-associated inflammation. Secondly, it focuses on the role of mitochondria and associated interventions to reduce cancer recurrence. Finally, the role of machine perfusion technology as a delivery tool and as an individual treatment is discussed together with the currently available clinical studies.

The Revolution in Indication for Liver Transplantation: Will Liver Metastatic Disease Overcome the End-Stage Liver Disease in the Next Future?

Indications for liver transplantation (LT) have constantly been evolving during the last few decades due to a better understanding of liver diseases and innovative therapies. Likewise, also the underlying causes of liver disease have changed. In the setting of transplant oncology, recent developments have pushed the boundaries of oncological indications for LT outside hepatocellular carcinoma (HCC), especially for secondary liver tumors, such as neuroendocrine and colorectal cancer. In the next years, as more evidence emerges, LT could become the standard treatment for well-selected metastatic liver tumors. In this manuscript, we review and summarize the available evidence for LT in liver tumors beyond HCC with a focus on metastatic liver malignancies, highlighting the importance of these new concepts for future implications.

Focus on Very Late Hepatocellular Carcinoma Recurring After Liver Transplantation: A Case Report and Literature Review

Hepatocellular carcinoma (HCC) recurring after liver transplantation (LT) is a major clinical concern, occurring in up to 20% and being the most frequent cause of death in this setting. Usually recurrence occurs within the first 2 years, whereas late and very late recurrences are rare. We report a 71-year-old woman with HCC recurrence after 25 years from LT, an event never reported before. Diagnosis was achieved with a progressive increase of alpha-fetoprotein (AFP) followed by a computed tomography scan, showing a mediastinal, upper diaphragmatic, right paracaval mass of 5 cm in size. The lesion was treated with a surgical approach involving a multidisciplinary team including hepatobiliary, thoracic, and cardiovascular surgeons. A sternotomy and mass removal was performed without the need of an extracorporeal bypass. A complete resection of the tumor was achieved, with a drop in AFP and without signs of recurrence after 1-year follow up. In conclusion, the possibility of late HCC recurrences after LT, despite being rare, underlines the need of a standardized, cost-benefit, optimal strategy of a long-term surveillance. From a surgical point of view, our case is unusual for the site and the character of the lesion, and for the absence of the need of an extracorporeal bypass during the operation.

De novo malignancies after liver transplantation: The effect of immunosuppression-personal data and review of literature

BACKGROUND

Immunosuppression has undoubtedly raised the overall positive outcomes in the post-operative management of solid organ transplantation. However, long-term exposure to immunosuppression is associated with critical systemic morbidities. De novo malignancies following orthotopic liver transplants (OLTs) are a serious threat in pediatric and adult transplant individuals. Data from different experiences were reported and compared to assess the connection between immunosuppression and de novo malignancies in liver transplant patients.

AIM

To study the role of immunosuppression on the incidence of de novo malignancies in liver transplant recipients.

METHODS

A systematic literature examination about de novo malignancies and immunosuppression weaning in adult and pediatric OLT recipients was described in the present review. Worldwide data were collected from highly qualified institutions performing OLTs. Patient follow-up, immunosuppression discontinuation and incidence of de novo malignancies were reported. Likewise, the review assesses the differences in adult and pediatric recipients by describing the adopted immunosuppression regimens and the different type of diagnosed solid and blood malignancy.

RESULTS

Emerging evidence suggests that the liver is an immunologically privileged organ able to support immunosuppression discontinuation in carefully selected recipients. Malignancies are often detected in liver transplant patients undergoing daily immunosuppression regimens. Post-transplant lymphoproliferative diseases and skin tumors are the most detected de novo malignancies in the pediatric and adult OLT population, respectively. To date, immunosuppression withdrawal has been achieved in up to 40% and 60% of well-selected adult and pediatric recipients, respectively. In both populations, a clear benefit of immunosuppression weaning protocols on de novo malignancies is difficult to ascertain because data have not been specified in most of the clinical experiences.

CONCLUSION

The selected populations of tolerant pediatric and adult liver transplant recipients greatly benefit from immunosuppression weaning. There is still no strong clinical evidence on the usefulness of immunosuppression withdrawal in OLT recipients on malignancies. An interesting focus is represented by the complete reconstitution of the immunological pathways that could help in decreasing the incidence of de novo malignancies and may also help in treating liver transplant patients suffering from cancer.

Feasibility of a protocol to wean patients from continuous renal replacement therapy: A retrospective pilot observation

PURPOSE

To evaluate the feasibility of a protocol-based algorithm to wean acute kidney injury (AKI) patients from continuous renal replacement therapy (CRRT).

METHODS

The protocol was introduced on one of two similarly equipped ICUs, while on the other (reference) ICU, CRRT discontinuation was based on clinical judgement. Patients were allocated to either ICU and were subjected to physician- or protocol-directed weaning, respectively. According to the algorithm, periodical withdrawal trials (WTs) were mandatory. Interventions were recommended (administration of diuretics, fluid, vasopressors, inotropes, or human albumin) to achieve specific goals (sufficient urine output, balanced fluid status, adequate renal perfusion pressure, optimal oxygen delivery, normoalbuminemia). Clearly stated criteria defined when to abort a WT and to resume RRT for one cycle, followed by another WT.

RESULTS

Urine output and S_cvO₂ during WTs were higher with protocol-directed weaning, as well as the amount of administered fluids. WT abort ratio was 48% with a tendency to prolonged WT duration, compared to 64% in the reference patients. No relevant adverse side effects were observed.

CONCLUSION

Our data show the feasibility of a structured approach to wean AKI patients from RRT that bundles established interventions and brings the weaning into the physician's focus.

Liver transplantation for hepatocellular carcinoma: Where do we stand?

Hepatocellular carcinoma represents an important cause of morbidity and mortality worldwide. It is the sixth most common cancer and the fourth leading cause of cancer death. Liver transplantation is a key tool for the treatment of this disease in human therefore hepatocellular carcinoma is increasing as primary indication for grafting. Although liver transplantation represents an outstanding therapy for hepatocellular carcinoma, due to organ shortage, the careful selection and management of patients who may have a major survival benefit after grafting remains a fundamental question. In fact, only some stages of the disease seem amenable of this therapeutic option, stimulating the debate on the appropriate criteria to select candidates. In this review we focused on current criteria to select patients with hepatocellular carcinoma for liver transplantation as well as on the strategies (bridging) to avoid disease progression and exclusion from grafting during the stay on wait list. The treatments used to bring patients within acceptable criteria (down-staging), when their tumor burden exceeds the standard criteria for transplant, are also reported. Finally, we examined tumor reappearance following liver transplantation. This occurrence is estimated to be approximately 8%-20% in different studies. The possible approaches to prevent this outcome after transplant are reported with the corresponding results.