Liver damage related to immune checkpoint inhibitors

Inhibition of growth of hepatocellular carcinoma by co-delivery of anti-PD-1 antibody and sorafenib using biomimetic nano-platelets

BACKGROUND

Traditional nanodrug delivery systems have some limitations, such as eliciting immune responses and inaccuracy in targeting tumor microenvironments.

MATERIALS AND METHODS

Targeted drugs (Sorafenib, Sora) nanometers (hollow mesoporous silicon, HMSN) were designed, and then coated with platelet membranes to form aPD-1-PLTM-HMSNs@Sora to enhance the precision of drug delivery systems to the tumor microenvironment, so that more effective immunotherapy was achieved.

RESULTS

These biomimetic nanoparticles were validated to have the same abilities as platelet membranes (PLTM), including evading the immune system. The successful coating of HMSNs@Sora with PLTM was corroborated by transmission electron microscopy (TEM), western blot and confocal laser microscopy. The affinity of aPD-1-PLTM-HMSNs@Sora to tumor cells was stronger than that of HMSNs@Sora. After drug-loaded particles were intravenously injected into hepatocellular carcinoma model mice, they were demonstrated to not only directly activate toxic T cells, but also increase the triggering release of Sora. The combination of targeted therapy and immunotherapy was found to be of gratifying antineoplastic function on inhibiting primary tumor growth.

CONCLUSIONS

The aPD-1-PLTM-HMSNs@Sora nanocarriers that co-delivery of aPD-1 and Sorafenib integrates unique biomimetic properties and excellent targeting performance, and provides a neoteric idea for drug delivery of personalized therapy for primary hepatocellular carcinoma (HCC).

A multicenter retrospective analysis: Factors influencing hepatic adverse events induced by immunotherapy in advanced liver cancer

OBJECTIVES

To analyze the clinical characteristics and influencing factors of hepatotoxicity in patients with advanced hepatocellular carcinoma (HCC) treated with programmed cell death protein-1 (PD-1) inhibitors, and to provide a theoretical basis for the treatment of immune-related hepatotoxicity in patients with advanced HCC.

METHODS

Retrospective analysis of clinical data of patients with advanced HCC from February 2021 to February 2023, in order to summarize and statistically analyze the influencing factors of immune-related liver adverse reactions.

RESULTS

A total of 135 patients met the inclusion criteria, among whom 46 patients experienced varying degrees of immune-related liver adverse reactions, with an incidence rate of 34.1% (46/135). The time range of immune-related liver adverse reactions was 3-26 weeks, with a median time of 4 weeks. The age range of immune-related liver adverse reactions was 34-73 years, with a median age of 62 years. Statistical analysis of the influencing factors and liver adverse reactions showed that age, total bilirubin level, and Child-Pugh (C-P) grading were influencing factors for the occurrence of liver adverse reactions (p < .05), and among these three influencing factors, the proportion of males with ≥2 influencing factors was higher than that of females; liver function C-P B was an independent influencing factor for liver adverse reactions (p < .05).

CONCLUSION

For male patients over 60 years old, with bilirubin levels ≥51 μmol/L and liver function C-P B, close observation of the occurrence of immune-related adverse reactions during treatment is recommended.

Research progress on rodent models and its mechanisms of liver injury

The liver is the most important organ for biological transformation in the body and is crucial for maintaining the body's vital activities. Liver injury is a serious pathological condition that is commonly found in many liver diseases. It has a high incidence rate, is difficult to cure, and is prone to recurrence. Liver injury can cause serious harm to the body, ranging from mild to severe fatty liver disease. If the condition continues to worsen, it can lead to liver fibrosis and cirrhosis, ultimately resulting in liver failure or liver cancer, which can seriously endanger human life and health. Therefore, establishing an rodent model that mimics the pathogenesis and severity of clinical liver injury is of great significance for better understanding the pathogenesis of liver injury patients and developing more effective clinical treatment methods. The author of this article summarizes common chemical liver injury models, immune liver injury models, alcoholic liver injury models, drug-induced liver injury models, and systematically elaborates on the modeling methods, mechanisms of action, pathways of action, and advantages or disadvantages of each type of model. The aim of this study is to establish reliable rodent models for researchers to use in exploring anti-liver injury and hepatoprotective drugs. By creating more accurate theoretical frameworks, we hope to provide new insights into the treatment of clinical liver injury diseases.

Computed tomography findings of hepatobiliary systems in patients with immune checkpoint inhibitor-induced liver injury

PURPOSE

The incidence of immune checkpoint inhibitor (ICI)-induced liver injury has increased recently; however, its imaging characteristics remain unclear. This study aimed to characterize the computed tomography (CT) findings of ICI-induced liver injury.

METHODS

This was a single-center retrospective study of patients with ICI-induced liver injury who underwent CT between January 2020 and December 2021. Two board-certified radiologists independently evaluated the CT findings of the patients before the start of ICI therapy (pre-CT) and at the onset of ICI-induced liver injury (post-CT) to determine the presence or absence of imaging findings suggestive of hepatitis and cholangitis. ICI-induced liver injury was classified into three categories based on the CT findings: hepatitis alone, cholangitis alone, and overlapped (cholangitis plus hepatitis).

RESULTS

A total of 19 patients were included in this study. Bile duct dilatation, bile duct wall thickening, non-edematous gallbladder wall thickening, hepatomegaly, periportal edema, and gallbladder wall edema were observed in the post-CT images of 12 (63.2%), 9 (60%), 11 (57.9%), 8 (42.1%), 6 (31.6%), and 2 (10.5%) patients, respectively. Wall thickening in the perihilar, distal, intrapancreatic bile duct and the cystic duct were observed in 53.3%, 60%, 46.7%, and 26.7% of the study population, respectively. Regarding the classification of ICI-induced liver injury, cholangitis alone was most common (36.8%), followed by overlapped (26.3%) and hepatitis alone (26.3%).

CONCLUSIONS

Patients with ICI-induced liver injury demonstrated a higher incidence of biliary abnormalities than hepatic abnormalities on CT images; nonetheless, future studies with larger sample sizes are needed to validate these findings.

Targeted co-delivery of PD-L1 monoclonal antibody and sorafenib to circulating tumor cells via platelet-functionalized nanocarriers

BACKGROUND

Circulating tumor cells (CTCs) can adsorb and activate platelets to form a microthrombus protective barrier around them, so that therapeutic drugs and immune cells cannot effectively kill CTCs. The platelet membrane (PM) bionic carrying drug system has the powerful ability of immune escape, and can circulate in the blood for a long time.

MATERIALS AND METHODS

we developed platelet membrane coated nanoparticles (PM HMSNs) to improve the precise delivery of drugs to tumor sites and to achieve more effective immunotherapy combined with chemotherapy strategy.

RESULTS

Successfully prepared aPD-L1-PM-SO@HMSNs particles, whose diameter is 95-130 nm and presenting the same surface protein as PM. Laser confocal microscopy and flow cytometry experimental results showed that the fluorescence intensity of aPD-L1-PM-SO@HMSNs was greater than SO@HMSNs that are not coated by PM. Biodistribution studies in H22 tumor-bearing mice showed that due to the combined action of the active targeting effect and the EPR effect, the high accumulation of aPD-L1-PM-SO@HMSNs in the local tumor was more effective in inhibiting tumor growth than other groups of therapeutic agents.

CONCLUSION

Platelet membrane biomimetic nanoparticles have a good targeted therapeutic effect, which can effectively avoid immune clearance and have little side effects. It provides a new direction and theoretical basis for further research on targeted therapy of CTCs in liver cancer.

Efficacy and safety of mycophenolate mofetil in treating immune-related hepatitis induced by immune checkpoint inhibitor use: A retrospective study

Background and Aim

To investigate the outcomes in eight Japanese patients with cancer treated with mycophenolate mofetil (MMF) and corticosteroids for immune checkpoint inhibitor treatment-induced severe immune-related hepatitis (ir-hepatitis) and the efficacy and safety of MMF.

Methods

We retrospectively examined patient background, treatment course, as well as examination and imaging data using electronic medical records.

Results

The ratio of male to female patients was 7:1, and the median age was 60 years (27-72 years). There were five and two cases of kidney cancer and malignant melanoma, respectively, and one case of lung cancer. The median number of days until MMF administration in addition to systemic corticosteroid therapy after the onset of ir-hepatitis was 14.5 (2-42). The patients were categorized as four "good responders" who showed an improvement in the liver function tests following MMF treatment and four "poor responders" who did not. Furthermore, the time from the onset of ir-hepatitis to initial MMF administration was significantly shorter in good responders (median 3 days, range 2-15 days) than in poor responders (median 25.5 days, range 14-42 days) (P = 0.042). No significant intergroup difference was observed in other clinical factors. No serious adverse events caused by MMF were observed in any case.

Conclusions

According to these findings, early recognition of corticosteroid refractoriness and the use of MMF may be beneficial in patients with ir-hepatitis.

3,3',5-triiodo-l-thyronine inhibits drug-induced liver injury through activation of PPARα as revealed by network pharmacology and biological experimental verification

Drug-induced liver injury (DILI) has increased in recent years, leading to acute liver failure. 3,3',5-triiodo-l-thyronine (T3) has been reported to exert a potent hepatoprotective effect. However, the mechanism and efficacy of T3 on DILI remain undocumented. In this study, an MTT assay was used to detect the effect of T3 on hepatotoxicity of acetaminophen (APAP) in L02 cells. Then, we screened key targets and related biological pathways by network pharmacology. Finally, enzyme-linked immunosorbent assay (ELISA) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to verify the mechanism and key targets of T3 on DILI. The results of the MTT assay showed that T3 significantly decreased hepatocellular injury induced by APAP. Network pharmacology and bioinformatics analysis showed that 118 intersection targets of T3 and DILI were identified and the mechanism of T3 on DILI was related to cell proliferation and oxidative stress. ELISA results showed that T3 may be an effective treatment for DILI as biomarkers of hepatocellular injury such as AST, ALP were decreased compared to APAP only treated cells, and the mechanism of T3 may be mediated in part through improving redox balance. The topological parameter screening results suggested 12 key targets of T3 for DILI. Among them, PPARα is associated with DILI, and activation of PPARα can reduce oxidative stress and cell necrosis. Therefore, PPARα was identified as a target for verification. qRT-PCR analysis demonstrated that T3 could reverse the down-regulation of PPARα induced by APAP exposure. Taken together, we demonstrated for the first time that T3 could activate PPARα, promote cell proliferation and reduce oxidative stress, and play a vital role in the treatment of DILI, which provides a reference for T3 as a candidate treatment for DILI.

Mycophenolate mofetil for immune checkpoint inhibitor‐related hepatotoxicity relapsing during dose reduction of corticosteroid: A report of two cases and literature review

Background

Immune checkpoint inhibitors (ICIs) sometimes cause immune‐related liver injury, which can lead to cessation of treatment, hospitalization, and even mortality. Although high‐dose corticosteroids are usually effective in treatment of ICI‐related liver injury, one fifth of affected patients require additional immunosuppressive therapy. It remains uncertain how best to treat ICI‐related liver injury that relapses under corticosteroid therapy after temporary remission.

Case

Here we report two cases of ICI‐related liver injury successfully treated with mycophenolate mofetil (MMF). In the first case, a 74‐year‐old man with stage IIIA lung cancer underwent curative chemoradiotherapy. After the second infusion of durvalumab, grade 3 ICI‐related liver injury (mixed pattern) developed. In the second case, a 46‐year‐old man with stage IVB lung cancer received pembrolizumab‐containing chemotherapy. After the first cycle, grade 2 ICI‐related hepatitis developed. In the both cases, liver injury improved with high‐dose prednisolone but relapsed during tapering of the drug. After liver biopsy was performed to confirm the diagnosis of ICI‐related liver injury, MMF (2000 mg/day) was added. MMF was effective for both patients and permitted discontinuation or reduction of prednisolone.

Conclusion

MMF appears to be an appropriate treatment option for ICI‐related liver injury that respond to high‐dose corticosteroids but relapse during steroid tapering.

Corticosteroid plus glycyrrhizin therapy for chronic drug- or herb-induced liver injury achieves biochemical and histological improvements: a randomised open-label trial

BACKGROUND

Treatment of chronic drug-induced liver injury (DILI) or herb-induced liver injury(HILI) is an important and unresolved challenge. There is no consensus regarding the indications for corticosteroids for chronic DILI/HILI.

AIMS

To investigate the efficacy and safety of corticosteroid plus glycyrrhizin for patients with chronic DILI/HILI.

METHODS

This was a randomised open-label trial. Eligible patients with causality assessment using the updated RUCAM were randomly assigned (1:1) either to the steroid treatment group (48-week stepwise dose reduction of methylprednisolone plus glycyrrhizin) or control group (glycyrrhizin alone). Liver biopsies were performed at baseline and at the end of the 48-week treatment period. The primary outcome was the proportion of patients with sustained biochemical response (SBR). The secondary outcomes were improvement in liver histology, time to biochemical normalisation and safety.

RESULTS

Of 80 participants, 70 (87.5%) completed the trial. The patients were predominantly female (77.5%), aged >40 years (77.5%) and had a hepatocellular injury pattern of DILI (71.2%). Compared to the control group, the treatment group showed a higher proportion of SBR (94.3% vs. 71.4%, p = 0.023), shorter biochemical normalisation time and histological improvements in both histological activity and fibrosis. The DILI and HILI subgroups, as well as the autoimmune hepatitis (AIH)-like DILI and non-AIH-like subgroups, showed comparable responses. No severe adverse events were observed during the trial.

CONCLUSION

This study provides the first clinical evidence that corticosteroid plus glycyrrhizin therapy for chronic DILI with or without AIH-like features can achieve both biochemical response and histological improvements with good safety. (ClinicalTrials.gov, NCT02651350).

Presence of autoantibodies in serum does not impact the occurrence of immune checkpoint inhibitor-induced hepatitis in a prospective cohort of cancer patients

Purpose

Immune checkpoint inhibitor (ICI)-induced hepatitis belongs to the frequently occurring immune-related adverse events (irAEs), particularly with the combination therapy involving ipilimumab and nivolumab. However, predisposing factors predicting the occurrence of ICI-induced hepatitis are barely known. We investigated the association of preexisting autoantibodies in the development of ICI-induced hepatitis in a prospective cohort of cancer patients.

Methods

Data from a prospective biomarker cohort comprising melanoma and non-small cell lung cancer (NSCLC) patients were used to analyze the incidence of ICI-induced hepatitis, putatively associated factors, and outcome.

Results

40 patients with melanoma and 91 patients with NSCLC received ICI between July 2016 and May 2019. 11 patients developed ICI-induced hepatitis (8.4%). Prior to treatment, 45.5% of patients in the hepatitis cohort and 43.8% of the control cohort showed elevated titers of autoantibodies commonly associated with autoimmune liver diseases (p = 0.82). We found two nominally significant associations between the occurrence of ICI-induced hepatitis and HLA alleles associated with autoimmune liver diseases among NSCLC patients. Of note, significantly more patients with ICI-induced hepatitis developed additional irAEs in other organs (p = 0.0001). Neither overall nor progression-free survival was affected in the hepatitis group.

Conclusion

We found nominally significant associations of ICI-induced hepatitis with two HLA alleles. ICI-induced hepatitis showed no correlation with liver-specific autoantibodies, but frequently co-occurred with irAEs affecting other organs. Unlike other irAEs, ICI-induced hepatitis is not associated with a better prognosis.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00432-021-03870-6.

Unraveling the Multifaceted Nature of CD8 T Cell Exhaustion Provides the Molecular Basis for Therapeutic T Cell Reconstitution in Chronic Hepatitis B and C

In chronic hepatitis B and C virus infections persistently elevated antigen levels drive CD8+ T cells toward a peculiar differentiation state known as T cell exhaustion, which poses crucial constraints to antiviral immunity. Available evidence indicates that T cell exhaustion is associated with a series of metabolic and signaling deregulations and with a very peculiar epigenetic status which all together lead to reduced effector functions. A clear mechanistic network explaining how intracellular metabolic derangements, transcriptional and signaling alterations so far described are interconnected in a comprehensive and unified view of the T cell exhaustion differentiation profile is still lacking. Addressing this issue is of key importance for the development of innovative strategies to boost host immunity in order to achieve viral clearance. This review will discuss the current knowledge in HBV and HCV infections, addressing how innate immunity, metabolic derangements, extensive stress responses and altered epigenetic programs may be targeted to restore functionality and responsiveness of virus-specific CD8 T cells in the context of chronic virus infections.

Immunosuppressive Nanoparticles for Management of Immune-Related Adverse Events in Liver

Immune checkpoint blockade (ICB) therapy has been considered as an effective way to boost immune cells to recognize and attack tumors. However, side effects known as immune-related adverse events (irAEs) should be carefully managed. Here, we engineer immunosuppressive nanoparticles by coating PD-L1 overexpressed mesenchymal stem cells (MSCs) plasma membrane on poly lactic-co-glycolic acid nanoparticles (MSC-PD-L1⁺ NPs) for managing and reducing irAEs induced by immune checkpoint inhibitors. The nanoparticles can enrich at liver site after intravenous administration. In the high dose of anti-PD-L1 mAb-induced irAEs clinically relevant mouse model, a low dose of MSC-PD-L1⁺ NPs (2 mg/kg) sufficiently rescues hepatitis by inactivating T cells and macrophages in the liver tissue. More intriguingly, due to the dose threshold for nanoparticles to the tumor site, we unexpectedly find that the injected NPs do not affect the efficiency of ICB therapy to inhibit solid tumor growth. Such a strategy shows potential for managing the various cancer immunotherapy associated irAEs in clinical applications.

Systemic treatment of HCC in special populations

Recent years have seen significant progress in the systemic treatment of hepatocellular carcinoma (HCC), including the advent of immunotherapy. While several large phase III trials have provided the evidence for a multi-line treatment paradigm, they have focused on a highly selected group of patients by excluding potentially confounding comorbidities. As a result, high quality evidence for the systemic treatment of HCC in patients with various comorbidities is missing. This review summarises current knowledge on the use of approved medicines in patients with HIV, autoimmune disease, cardiovascular disease, diabetes, fibrolamellar HCC, mixed HCC-cholangiocarcinoma, decompensated cirrhosis (Child-Pugh B and C), a significant bleeding history, vascular invasion or portal vein thrombosis, as well as the elderly, those on haemodialysis, and those after solid organ transplantation. The article highlights relevant knowledge gaps and current clinical challenges. To improve the safety and efficacy of HCC treatment in these subgroups, future trials should be designed to specifically include patients with comorbidities.

Idiosyncratic Drug-Induced Liver Injury: Mechanistic and Clinical Challenges

Idiosyncratic drug-induced liver injury (IDILI) remains a significant problem for patients and drug development. The idiosyncratic nature of IDILI makes mechanistic studies difficult, and little is known of its pathogenesis for certain. Circumstantial evidence suggests that most, but not all, IDILI is caused by reactive metabolites of drugs that are bioactivated by cytochromes P450 and other enzymes in the liver. Additionally, there is overwhelming evidence that most IDILI is mediated by the adaptive immune system; one example being the association of IDILI caused by specific drugs with specific human leukocyte antigen (HLA) haplotypes, and this may in part explain the idiosyncratic nature of these reactions. The T cell receptor repertoire likely also contributes to the idiosyncratic nature. Although most of the liver injury is likely mediated by the adaptive immune system, specifically cytotoxic CD8+ T cells, adaptive immune activation first requires an innate immune response to activate antigen presenting cells and produce cytokines required for T cell proliferation. This innate response is likely caused by either a reactive metabolite or some form of cell stress that is clinically silent but not idiosyncratic. If this is true it would make it possible to study the early steps in the immune response that in some patients can lead to IDILI. Other hypotheses have been proposed, such as mitochondrial injury, inhibition of the bile salt export pump, unfolded protein response, and oxidative stress although, in most cases, it is likely that they are also involved in the initiation of an immune response rather than representing a completely separate mechanism. Using the clinical manifestations of liver injury from a number of examples of IDILI-associated drugs, this review aims to summarize and illustrate these mechanistic hypotheses.

Drug-induced liver injury: Asia Pacific Association of Study of Liver consensus guidelines

Idiosyncratic drug-induced liver injury mimics acute and chronic liver disease. It is under recognized and underrecognised because of the lack of pathognomonic diagnostic serological markers. Its consequences may vary from being asymptomatic to self-limiting illness to severe liver injury leading to acute liver failure. Its incidence is likely to be more common in Asia than other parts of the world, mainly because of hepatotoxicity resulting from the treatment of tuberculosis disease and the ubiquitous use of traditional and complimentary medicines in Asian countries. This APASL consensus guidelines on DILI is a concise account of the various aspects including current evidence-based information on DILI with special emphasis on DILI due to antituberculosis agents and traditional and complementary medicine use in Asia.

Recent updates on the management of autoimmune hepatitis

Autoimmune hepatitis (AIH) is an immunoinflammatory chronic liver disease with dynamic and rather heterogeneous disease manifestations. A trend of increasing prevalence of AIH has been observed worldwide, along with a relative increase in the percentage of male patients. AIH is characterized and diagnosed based on serum biochemistry and liver histology: elevated aminotransferases and serum immunoglobulin G (IgG), the presence of serum anti-nuclear antibody or anti-smooth muscle antibody, and interface lympho-plasmacytic hepatitis. Clinical manifestations differ among disease subtypes with distinct time-frames, i.e., AIH with a chronic insidious onset, and acute-onset AIH (the diagnosis of which is often challenging due to the lack of typical serum findings). The absence of disease-specific biomarkers or histological findings may expand the disease phenotype into drug-induced AIH-like liver injury. Corticosteroids and azathioprine are recommended first-line treatments for AIH. The complete normalization of aminotransferases and serum IgG is an essential treatment response to ensure long-term overall survival. An incomplete response or intolerance to these drugs is considered an indication for second-line treatment, especially with mycophenolate mofetil. Life-long maintenance treatment is required for the majority of patients, but the few who achieve prolonged and stringent biochemical remission with lower alanine aminotransferase and IgG within the normal range may be able to discontinue the medications. In the future, the quality of life of AIH patients should be managed by personalized medicine, including the appropriate selection and dosing of first-line therapy and perhaps alternating with potential therapeutics, and the prediction of the success of treatment withdrawal.

Approach to the patient with acute severe autoimmune hepatitis

Autoimmune hepatitis is associated with varied clinical presentations and natural history, as well as somewhat unpredictable treatment responses. Understanding how to stratify patients who require further escalation of therapy will help clinicians manage these patients. The presentation of acute severe autoimmune hepatitis (AS-AIH) is relatively uncommon, although its prevalence is potentially greater than currently perceived. Previous studies consist of small retrospective single-centre series and are not directly comparable due to the diversity of presentations, disease definitions and non-standardised treatment regimens. We define AS-AIH as those who present acutely with AIH and are icteric with an international normalised ratio ≥1.5 and no evidence of hepatic encephalopathy. Those with hepatic encephalopathy should be defined as having AS-AIH with acute liver failure. In this review, we provide a structured practical approach for diagnosing and managing this unique group of patients.

Overcoming Immune Evasion in Melanoma

Melanoma is the most aggressive and dangerous form of skin cancer that develops from transformed melanocytes. It is crucial to identify melanoma at its early stages, in situ, as it is "curable" at this stage. However, after metastasis, it is difficult to treat and the five-year survival is only 25%. In recent years, a better understanding of the etiology of melanoma and its progression has made it possible for the development of targeted therapeutics, such as vemurafenib and immunotherapies, to treat advanced melanomas. In this review, we focus on the molecular mechanisms that mediate melanoma development and progression, with a special focus on the immune evasion strategies utilized by melanomas, to evade host immune surveillances. The proposed mechanism of action and the roles of immunotherapeutic agents, ipilimumab, nivolumab, pembrolizumab, and atezolizumab, adoptive T- cell therapy plus T-VEC in the treatment of advanced melanoma are discussed. In this review, we implore that a better understanding of the steps that mediate melanoma onset and progression, immune evasion strategies exploited by these tumor cells, and the identification of biomarkers to predict treatment response are critical in the design of improved strategies to improve clinical outcomes for patients with this deadly disease.

Multidisciplinary Clinical Approach to Cancer Patients with Immune-Related Adverse Events Induced by Checkpoint Inhibitors

Immune-oncology is a major breakthrough in cancer treatment and has become the standard of care for a wide variety of solid organ malignancies. Unfortunately, manipulation of the immune system with checkpoint inhibitors may result in an immune-based attack of normal tissues which can lead to treatment discontinuation. These immune-related adverse events (irAEs) are diverse and affect several organs, constituting a new clinical challenge in the management of cancer patients. The complexity of this scenario requires a multidisciplinary approach that allows the early identification, diagnosis and treatment of specific irAE, ruling out other non-related adverse events. Hospital Clinic has a multidisciplinary team seeking to develop a coordinated strategy to facilitate the access of patients with suspected irAEs to specialised care resulting in harmonised management that guarantees the best patient care. The aim of the manuscript was to describe the current evidence on the management of irAEs reflecting a coordinated multidisciplinary approach to face this clinical challenge regardless of the immunotherapy indication.

Checkpoint Inhibition Causing Complete Remission of Metastatic Combined Hepatocellular-Cholangiocarcinoma after Hepatic Resection

Combined hepatocellular-cholangiocarcinoma (CHC) is a rare type of primary liver cancer, speculated to arise from hepatic progenitor cells, and with a worse prognosis than hepatocellular carcinoma (HCC). Serum alpha-fetoprotein (AFP) levels may be one prognostic factor. It has been suggested that checkpoint inhibition might be useful in the treatment of HCC where there is an increased expression of PD-1 and PD-L1 in the microenvironment. Its effect on CHC is unknown. We report a case with a large CHC, which was radically resected, but the 53-year-old female patient subsequently developed pulmonary metastases. Histology demonstrated low-differentiated CHC without microsatellite instability. Treatment with sorafenib was started but was stopped due to angioedema. Under subsequent gemcitabine/cisplatin treatment, the metastatic disease progressed with rising AFP levels. A third-line treatment with pembrolizumab was then started, 2 mg/kg b.w. i.v. every third week for 6 months. This resulted in a radiologically complete remission of the pulmonary metastases and AFP levels were normalized (<10 μg/L) from a level of 1,790 μg/L before treatment. The patient developed immune-related adverse events (AEs) including diarrhea and hepatitis. These AEs were successfully treated with prednisolone and mycophenolate mofetil, and they were eventually resolved. There are no signs of cancer recurrence neither in the liver nor in the lungs at 33 months after the start of the checkpoint inhibition treatment, and the patient is doing well. Further study is urgently needed on the role of checkpoint inhibition therapy in liver cancer.

Characterization of risk factors and efficacy of medical management of immune-related hepatotoxicity in real-world patients with metastatic melanoma treated with immune checkpoint inhibitors

INTRODUCTION

Immune-related hepatitis (ir-hepatitis) is a common side-effect of checkpoint inhibitors (CPIs). Here, we characterise ir-hepatitis in a large cohort of patients with metastatic melanoma (MM) treated with CPIs and describe potential risk factors and efficacy of medical management.

METHODS

The retrospective study included a large cohort of patients with MM treated with CPIs between 2010 and 2019. Patients were retrieved from the national Danish Metastatic Melanoma Database.

RESULTS

Five hundred twenty one patients were included. Ir-hepatitis was found in 6.8% of patients. Combination therapy was associated with a significantly greater risk than monotherapy. Of all patients, 34.9% with hepatitis had a different hepatitis grading, when based on either alanine transaminase (ALT) or aspartate transaminase (AST) levels. Of all patients, 72.1% with hepatitis received steroid treatment, and two patients received additional second-line immunosuppressants. Of all patients, 35.5% experienced hepatitis relapse during steroid tapering. Of all patients, 18.6% and 25% of patients with grade ≥2 and ≥ III3, respectively, developed hepatitis within 7 days after finishing an antibiotic treatment for infection. Patients (62.5%) who received a cumulative dose of >4000 mg steroid experienced cancer progression, compared with 22.7% of patients treated with <4000 mg.

CONCLUSION

Several observations of clinical importance were made. Infection and antibiotic treatment during CPIs could be a possible risk factor for developing ir-hepatitis. Severity of ir-hepatitis is potentially underestimated in a significant number of patients, if only one liver enzyme is measured. The role of second-line immunosuppressants needs to be further investigated because of the high risk of hepatitis relapse during steroid tapering and the potential negative impact of cumulative steroid dose on response to CPIs.

Examining pathogenic concepts of autoimmune hepatitis for cues to future investigations and interventions

BACKGROUND

Multiple pathogenic mechanisms have been implicated in autoimmune hepatitis, but they have not fully explained susceptibility, triggering events, and maintenance or escalation of the disease. Furthermore, they have not identified a critical defect that can be targeted. The goals of this review are to examine the diverse pathogenic mechanisms that have been considered in autoimmune hepatitis, indicate investigational opportunities to validate their contribution, and suggest interventions that might evolve to modify their impact. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Genetic and epigenetic factors can affect susceptibility by influencing the expression of immune regulatory genes. Thymic dysfunction, possibly related to deficient production of programmed cell death protein-1, can allow autoreactive T cells to escape deletion, and alterations in the intestinal microbiome may help overcome immune tolerance and affect gender bias. Environmental factors may trigger the disease or induce epigenetic changes in gene function. Molecular mimicry, epitope spread, bystander activation, neo-antigen production, lymphocytic polyspecificity, and disturbances in immune inhibitory mechanisms may maintain or escalate the disease. Interventions that modify epigenetic effects on gene expression, alter intestinal dysbiosis, eliminate deleterious environmental factors, and target critical pathogenic mechanisms are therapeutic possibilities that might reduce risk, individualize management, and improve outcome. In conclusion, diverse pathogenic mechanisms have been implicated in autoimmune hepatitis, and they may identify a critical factor or sequence that can be validated and used to direct future management and preventive strategies.

Predictive Factors for Response to PD-1/PD-L1 Checkpoint Inhibition in the Field of Hepatocellular Carcinoma: Current Status and Challenges

Immunotherapies targeting immune checkpoints are fast-developing therapeutic approaches adopted for several tumor types that trigger unprecedented rates of durable clinical responses. Immune checkpoint programmed cell death protein 1 (PD-1), expressed primarily by T cells, and programmed cell death ligand 1 (PD-L1), expressed mainly by tumor cells, macrophages, and dendritic cells, are molecules that impede immune function, thereby allowing tumor cells to proliferate, grow and spread. PD-1/PD-L1 checkpoint inhibitors have emerged as a promising treatment strategy of hepatocellular carcinoma (HCC). However, only a minority of HCC patients benefit from this therapy. To find a niche for immune checkpoint inhibition in HCC patients, future strategies might require predictive factor-based patient selection, to identify patients who are likely to respond to the said therapy and combination strategies in order to enhance anti-tumor efficacy and clinical success. This review provides an overview of the most recent data pertaining to predictive factors for response to PD-1/PD-L1 checkpoint inhibition in the field of HCC.

Checkpoint inhibitor-induced liver injury: A novel form of liver disease emerging in the era of cancer immunotherapy

Liver injury triggered by immune checkpoint inhibitors has been increasingly seen in clinical practice, and the incidence is likely to rise further in the next several years because of expanded indications for cancer immunotherapy. Tissue damage driven by disrupted immune tolerance against self-antigens is called an immune-related adverse event (irAE). irAEs in the liver histologically presents panlobular hepatitis (∼70%), isolated central zonal necrosis (∼20%), primarily granulomatous hepatitis (∼5%), and other minor forms of tissue injury (∼5%). Infiltrating cells are mainly lymphocytes and occasional eosinophils. Unlike classic autoimmune hepatitis (AIH), plasma cell infiltration is not conspicuous. Immunostaining reveals a large number of CD8+ T lymphocytes and a markedly smaller number of CD4+ cells or CD20+ B lymphocytes. The unique CD3+/CD20+ and CD4+/CD8+ ratios shifted in favor of CD8+ cytotoxic T lymphocytes are helpful to discriminate irAEs from other conditions (e.g., AIH, idiosyncratic drug-induced liver injury). Another hepatobiliary manifestation of irAEs is sclerosing cholangitis clinically characterized by elevations of biliary enzymes, diffuse duct wall thickening, and duct dilatation. Lymphocytic infiltration can be observed by endoscopic biopsies from the thick extrahepatic bile ducts, and liver needle biopsies may also show severe lymphocytic cholangitis resembling primary biliary cholangitis. An important differential diagnosis of irAEs is previously asymptomatic or subclinical liver disease unmasked by cancer immunotherapy, which is often challenging and requires close clinicopathological correlations.

Immune inhibitory proteins and their pathogenic and therapeutic implications in autoimmunity and autoimmune hepatitis

Key inhibitory proteins can blunt immune responses to self-antigens, and deficiencies in this repertoire may promote autoimmunity. The goals of this review are to describe the key immune inhibitory proteins, indicate their possible impact on the development of autoimmune disease, especially autoimmune hepatitis, and encourage studies to clarify their pathogenic role and candidacy as therapeutic targets. English abstracts were identified in PubMed by multiple search terms. Full length articles were selected for review, and secondary and tertiary bibliographies were developed. Cytotoxic T lymphocyte antigen-4 impairs ligation of CD28 to B7 ligands on antigen presenting cells and inhibits the adaptive immune response by increasing anti-inflammatory cytokines, generating regulatory T cells, and reducing T cell activation and proliferation. Programed cell death antigen-1 inhibits T cell selection, activation, and proliferation by binding with two ligands at different phases and locations of the immune response. A soluble alternatively spliced variant of this protein can dampen the inhibitory signal. Autoimmune hepatitis has been associated with polymorphisms of the cytotoxic T lymphocyte antigen-4 gene, reduced hepatic expression of a ligand of programed cell death antigen-1, an interfering soluble variant of this key inhibitory protein, and antibodies against it. Findings have been associated with laboratory indices of liver injury and suboptimal treatment response. Abatacept, belatacept, CD28 blockade, and induction of T cell exhaustion are management considerations that require scrutiny. In conclusion, deficiencies in key immune inhibitory proteins may promote the occurrence of autoimmune diseases, such as autoimmune hepatitis, and emerging interventions may overcome these deficiencies. Investigations should define the nature, impact and management of these inhibitory disturbances in autoimmune hepatitis.

HBV Immune-Therapy: From Molecular Mechanisms to Clinical Applications

Chronic hepatitis B virus (HBV) infection represents a worldwide public health concern with approximately 250 million people chronically infected and at risk of developing liver cirrhosis and hepatocellular carcinoma. Nucleos(t)ide analogues (NUC) are the most widely used therapies for HBV infection, but they often require long-lasting administration to avoid the risk of HBV reactivation at withdrawal. Therefore, there is an urgent need to develop novel treatments to shorten the duration of NUC therapy by accelerating virus control, and to complement the effect of available anti-viral therapies. In chronic HBV infection, virus-specific T cells are functionally defective, and this exhaustion state is a key determinant of virus persistence. Reconstitution of an efficient anti-viral T cell response may thus represent a rational strategy to treat chronic HBV patients. In this perspective, the enhancement of adaptive immune responses by a checkpoint inhibitor blockade, specific T cell vaccines, lymphocyte metabolism targeting, and autologous T cell engineering, including chimeric antigen receptor (CAR) and TCR-redirected T cells, constitutes a promising immune modulatory approach for a therapeutic restoration of protective immunity. The advances of the emerging immune-based therapies in the setting of the HBV research field will be outlined.