Hepatotoxicity of immune checkpoint inhibitors: a histology study of seven cases in comparison with autoimmune hepatitis and idiosyncratic drug-induced liver injury

Cellular interactions in self-directed immune-mediated liver diseases

The lymphocyte population must traverse a complex path throughout their journey to the liver. The signals which these cells must detect, including cytokines, chemokines and other soluble factors, steer their course towards further crosstalk with other hepatic immune cells, hepatocytes and biliary epithelial cells. A series of specific chemokine receptors and adhesion molecules drive not only the recruitment, migration, and retention of these cells within the liver, but also their localisation. Perturbation of these interactions and failure of self-recognition drive the development of several autoimmune liver diseases. We also describe check point-induced liver injury. Immune cell internalisation into hepatocytes (emperipolesis) in autoimmune hepatitis and into biliary epithelial cells (intra-epithelial lymphocyte) in primary biliary cholangitis are typical features in autoimmune liver diseases. Finally, we describe emerging immune-based therapies, including regulatory T cell, anti-cytokine and anti-chemokine therapies, cytokine supplementation (e.g. interleukin-2), as well as co-inhibitory molecule manipulation, including T-cell engagers, and discuss their potential application in the treatment of autoimmune liver diseases.

Antigen presentation potential is variable among human ovarian tumour and syngeneic murine models and dictates pre-clinical outcomes of immunotherapy

High grade serous ovarian carcinoma (HGSC) is a fatal gynaecological malignancy with limited therapeutic options. Immunotherapies targeting MHC-I-dependent antigen presentation offer potential. Currently, the antigen presentation machinery (APM) of widely used syngeneic murine HGSC models remains poorly characterised, limiting translational relevance. Here, we systematically evaluate APM gene expression in syngeneic murine and patient samples. Tap1 and Psmb8 were identified as critical APM markers, deficient in murine models and strongly correlating with MHC-I expression. Hierarchical clustering correlation analysis using these markers revealed that ID8-p53⁻/⁻BRCA1⁻/⁻ was the most strongly correlated model and aligned with the largest patient subset. Moreover, ID8-ip1 correlated to the smaller second patient subset strongly. The low MHC-I expressing IG10 model was unique clustering alongside patient derived LP28 tumour and not fitting either patient subset. In vivo test of a novel combination immune therapy consisting of Flt3L, Poly(I:C), and paclitaxel therapy demonstrated significantly reduced tumour burden in high APM models (p53⁻/⁻BRCA1⁻/⁻, ID8-ip1; p < 0.01), but not IG10. Furthermore, high expressing MHC-I models were linked to enhanced DC expansion, CD8⁺ T-cell infiltration, and effector differentiation (131 % increase in ID8-ip1), alongside improved CD8⁺ T-cell activation and CD86⁺ B-cell co-stimulation. These findings establish MHC-I as a predictive biomarker for immunotherapy response and underscore the need for APM-enhancing strategies in antigen-poor tumours. By bridging murine models to human APM heterogeneity, this work provides a framework for optimising preclinical immunotherapy evaluation and patient stratification, advancing tailored therapeutic approaches for HGSC.

Transcriptomic and proteomic characterization of cell and protein biomarkers of checkpoint inhibitor-induced liver injury

Immune checkpoint inhibitors (ICI) targeting CTLA-4 and PD-1 have shown remarkable antitumor efficacy, but can also cause immune-related adverse events, including checkpoint inhibitor-induced liver injury (ChILI). This multi-omic study aimed to investigate changes in blood samples from treated cancer patients who developed ChILI. PBMCs were sequenced for by transcriptomic and T cell receptor repertoire (bulk and single-cell immune profiling), and extracellular vesicle (EV) enrichment from plasma was analyzed by mass spectroscopy proteomics. Data were analyzed by comparing the ChILI patient group to the control group who did not develop ChILI and by comparing the onset of ChILI to pre-ICI treatment baseline. We identified significant changes in T cell clonality, gene expression, and proteins in peripheral blood mononuclear cells (PBMCs) and plasma in response to liver injury. Onset of ChILI was accompanied by an increase in T cell clonality. Pathway analysis highlighted the involvement of innate and cellular immune responses, mitosis, pyroptosis, and oxidative stress. Single-cell RNA sequencing revealed that these changes were primarily found in select T cell subtypes (including CD8 + effector memory cells), while CD16 + monocytes exhibited enrichment in metabolic pathways. Proteomic analysis of plasma extracellular vesicles showed enrichment in liver-associated proteins among differentially expressed proteins. Interestingly, an increase in PBMC PD-L1 gene expression and plasma PD-L1 protein was also found to be associated with ChILI onset. These findings provide valuable insights into the immune and molecular mechanisms underlying ChILI as well as potential biomarkers of ChILI.Trial registration number NCT04476563.

Secondary Sclerosing Cholangitis due to Drugs With a Special Emphasis on Checkpoint Inhibitors

BACKGROUND

Secondary sclerosing cholangitis (SSC), is one of the phenotypes of DILI first described in the 1980s. Check point inhibitors (CPIs) are currently the most frequent cause of SCC.

AIMS

To describe the epidemiology, clinical and biochemical features at presentation, differential diagnoses, pathophysiology, imaging, histological characteristics and management associated with SSC.

MATERIALS AND METHODS

A language and date-unrestricted Medline literature search was conducted to identify case reports and clinical series on SSC with special emphasis on CPIs (2007-2023).

RESULTS

We identified 19 different drugs that have been shown to induce SSC. A total of 64 cases with SSC due to CPIs are presented. This was mostly seen in patients treated with anti-Programmed cell death (PD)-1/PD-L1 inhibitors. The most frequent presenting signs and symptoms were abdominal pain and jaundice. Large-duct cholangitis induced by CPIs is a very rare condition while small-duct cholangitis is more common. Nivolumab and pembrolizumab were the most commonly implicated agents. Biopsies have revealed predominant CD8+ T cell infiltration in biliary strictures. Corticosteroids is linked to a low frequency of success and is the only agent recommended to begin the treatment.

CONCLUSIONS

CPIs-induced SSC seems to affect the entire biliary system. Clinicians should consider and suspect SSC when a probable CPIs-induced hepatitis does not respond to corticosteroids. Additionally, further randomized, controlled trials should prospectively investigate alternative therapies for treatment.

Clinical features and pathological findings by liver biopsy in patients with immune-related sclerosing cholangitis induced by immune checkpoint inhibitors

BACKGROUND

Immune-related sclerosing cholangitis (irSC) induced by immune checkpoint inhibitors (ICIs) is relatively rare, and its clinical and pathological features are not well known.

AIMS

We aimed to compare the clinical course and pathological findings of irSC with those of non-irSC liver injury.

METHODS

Clinical data were retrospectively collected from 2416 patients with advanced malignancies treated with ICIs between September 2014 and October 2023. The data of patients with severe ICI-induced liver injury who underwent liver biopsy were analyzed and compared between patients with irSC and non-irSC.

RESULTS

Ninety-three (3.8 %) patients had severe ICI-induced liver injury, and 38 underwent liver biopsy. Of these, five were diagnosed with irSC. The irSC group had a significantly longer time to onset of ICI-induced liver injury and a lower rate of improvement of liver injury than did the non-irSC group (irSC, 3/5; non-irSC, 32/33). Liver biopsies revealed more moderate-to-severe pathological cholangitis in the irSC group than in the non-irSC group (irSC, n = 5/5; non-irSC, n = 16/33). Other pathological findings were similar between the two groups.

CONCLUSION

Appropriate management of irSC requires an understanding of its characteristics of late onset and steroid resistance, and liver biopsy, in addition to imaging, may be useful for diagnosing irSC.

Role of liver biopsy in the management of idiosyncratic DILI

Drug-induced liver injury (DILI) presents unique challenges in clinical practice. While some types of DILI are mild and resolve quickly after removing the drug, other situations are more complex, with competing aetiologies or underlying liver disease. Guidelines from professional societies agree that the liver biopsy retains a role in understanding and managing DILI in certain situations. Liver biopsy allows characterization of the histological pattern of injury as well as assessment of severity. Inflammatory infiltrates, bile duct injury or loss and vascular injury are all revealed by liver biopsy. Communication between the hepatopathologist and clinical team with clinicopathological correlation of the findings is necessary for the best determination of causality and differentiation from other diseases of exclusion, like autoimmune hepatitis and graft-versus-host disease. This review highlights important aspects of the role of liver biopsy in DILI evaluation.

Real-world pharmacovigilance study of drug-induced autoimmune hepatitis from the FAERS database

This study aims to identify and evaluate the most common drugs associated with the risks of autoimmune hepatitis (AIH) using the FDA Adverse Event Reporting System (FAERS) database. Adverse drug events (ADEs) associated with drug-induced AIH (DI-AIH) were retrieved from the FAERS database (January 2004-June 2024). Disproportionality analysis was performed to identify drugs significantly linked to DI-AIH, and time-to-onset (TTO) analyses were conducted to evaluate the timing and risk profiles of DI-AIH adverse reactions. Our study identified 2,511 ADEs linked to autoimmune hepatitis. Disproportionality analysis identified 22 drugs significantly associated with AIH risk, including 4 antibiotics, 3 antivirals, 4 cardiovascular drugs, 5 antitumor agents, 2 immunomodulators, 2 nonsteroidal anti-inflammatory drugs, and 1 drug each from the respiratory and nervous system categories. The highest DI-AIH risks were observed with minocycline (ROR = 53.97), nitrofurantoin (ROR = 57.02), and doxycycline (ROR = 16.12). Antitumor drugs had the shortest median TTO (77.00 days), whereas cardiovascular drugs exhibited the longest (668.30 days). Through a comprehensive analysis of the FAERS database, our study identified drugs strongly associated with AIH. Preventing DI-AIH requires careful drug selection and monitoring. This study provides evidence-based insights into implicated drugs, aiming to optimize clinical management and mitigate risks.

Drug-Induced Liver Injury Associated With Emerging Cancer Therapies

Targeted therapies and immunotherapies have shown great promise as best-in-class treatments for several cancers with respect to efficacy and safety. While liver test abnormalities are rather common in patients treated with kinase inhibitors or immunotherapy, events of severe hepatotoxicity in these patients are rare in comparison with those associated with chemotherapeutics. The underlying mechanisms and risk factors for severe hepatotoxicity with novel oncology therapies are not well understood, complicating the drug-induced liver injury (DILI) risk assessment in the preclinical and clinical phases of drug development. The epidemiological and clinical characteristics, as well as mechanisms of liver toxicity, are described here to the current state of knowledge. Tools to study and assess the risk of DILI during drug development are concisely summarised, focusing on caveats thereof for novel oncology treatments. Emerging tools to optimise safety assessments and gather additional mechanistic insights into DILI are introduced. Particularly in oncology, where standard liver signals during drug development are tolerated to a marginally higher degree than in other indications due to the life-saving, life-extending and quality-of-life improvements for patients with severe or advanced cancers versus previous standard-of-care therapeutics, safety assessments must be tailored to the drug and indication. Trends in patient safety-centred drug development programmes and regulatory approval processes must continually be revisited and streamlined via obtaining an overall greater understanding of DILI and the tools available to assess mechanisms of injury, frequency, severity and prognosis.

Single cell profiling of circulating autoreactive CD4 T cells from patients with autoimmune liver diseases suggests tissue imprinting

Autoimmune liver diseases (AILD) involve dysregulated CD4 T cell responses against liver self-antigens, but how these autoreactive T cells relate to liver tissue pathology remains unclear. Here we perform single-cell transcriptomic and T cell receptor analyses of circulating, self-antigen-specific CD4 T cells from patients with AILD and identify a subset of liver-autoreactive CD4 T cells with a distinct B-helper transcriptional profile characterized by PD-1, TIGIT and HLA-DR expression. These cells share clonal relationships with expanded intrahepatic T cells and exhibit transcriptional signatures overlapping with tissue-resident T cells in chronically inflamed environments. Using a mouse model, we demonstrate that, following antigen recognition in the liver, CD4 T cells acquire an exhausted phenotype, play a crucial role in liver damage, and are controlled by immune checkpoint pathways. Our findings thus suggest that circulating autoreactive CD4 T cells in AILD are imprinted by chronic antigen exposure to promote liver inflammation, thereby serving as a potential target for developing biomarkers and therapies for AILD.

Hepatotoxicity in Cancer Immunotherapy: Diagnosis, Management, and Future Perspectives

Cancer immunotherapy, particularly immune checkpoint inhibitors, has positively impacted oncological treatments. Despite its effectiveness, immunotherapy is associated with immune-related adverse events (irAEs) that can affect any organ, including the liver. Hepatotoxicity primarily manifests as immune-related hepatitis and, less frequently, cholangitis. Several risk factors, such as pre-existing autoimmune and liver diseases, the type of immunotherapy, and combination regimens, play a role in immune-related hepatotoxicity (irH), although reliable predictive markers or models are still lacking. The severity of irH ranges from mild to severe cases, up to, in rare instances, acute liver failure. Management strategies require regular monitoring for early diagnosis and interventions, encompassing strict monitoring for mild cases to the permanent suspension of immunotherapy for severe forms. Corticosteroids are the backbone of treatment in moderate and high-grade damage, alone or in combination with additional immunosuppressive drugs for resistant or refractory cases. Given the relatively low number of events and the lack of dedicated prospective studies, much uncertainty remains about the optimal management of irH, especially in the most severe cases. This review presents the main features of irH, focusing on injury patterns and mechanisms, and provides an overview of the management landscape, from standard care to the latest evidence.

Granulomatous inflammatory responses are elicited in the liver of PD-1 knockout mice by de novo genome mutagenesis

Introduction

Programmed death-1 (PD-1) is a negative regulator of immune responses. Upon deletion of PD-1 in mice, symptoms of autoimmunity developed only after they got old. In a model experiment in cancer immunotherapy, PD-1 was shown to prevent cytotoxic T lymphocytes from attacking cancer cells that expressed neoantigens derived from genome mutations. Furthermore, the larger number of genome mutations in cancer cells led to more robust anti-tumor immune responses after the PD-1 blockade. To understand the common molecular mechanisms underlying these findings, we hypothesize that we might have acquired PD-1 during evolution to avoid/suppress autoimmune reactions against neoantigens derived from mutations in the genome of aged individuals.

Methods

To test the hypothesis, we introduced random mutations into the genome of young PD-1-/- and PD-1+/+ mice. We employed two different procedures of random mutagenesis: administration of a potent chemical mutagen N-ethyl-N-nitrosourea (ENU) into the peritoneal cavity of mice and deletion of MSH2, which is essential for the mismatch-repair activity in the nucleus and therefore for the suppression of accumulation of random mutations in the genome.

Results

We observed granulomatous inflammatory changes in the liver of the ENU-treated PD-1 knockout (KO) mice but not in the wild-type (WT) counterparts. Such lesions also developed in the PD-1/MSH2 double KO mice but not in the MSH2 single KO mice.

Conclusion

These results support our hypothesis about the physiological function of PD-1 and address the mechanistic reasons for immune-related adverse events observed in cancer patients having PD-1-blockade immunotherapies.

IL-2-mediated hepatotoxicity: knowledge gap identification based on the irAOP concept

Drug-induced hepatotoxicity constitutes a major reason for non-approval and post-marketing withdrawal of pharmaceuticals. In many cases, preclinical models lack predictive capacity for hepatic damage in humans. A vital concern is the integration of immune system effects in preclinical safety assessment. The immune-related Adverse Outcome Pathway (irAOP) approach, which is applied within the Immune Safety Avatar (imSAVAR) consortium, presents a novel method to understand and predict immune-mediated adverse events elicited by pharmaceuticals and thus targets this issue. It aims to dissect the molecular mechanisms involved and identify key players in drug-induced side effects. As irAOPs are still in their infancy, there is a need for a model irAOP to validate the suitability of this tool. For this purpose, we developed a hepatotoxicity-based model irAOP for recombinant human IL-2 (aldesleukin). Besides producing durable therapeutic responses against renal cell carcinoma and metastatic melanoma, the boosted immune activation upon IL-2 treatment elicits liver damage. The availability of extensive data regarding IL-2 allows both the generation of a comprehensive putative irAOP and to validate the predictability of the irAOP with clinical data. Moreover, IL-2, as one of the first cancer immunotherapeutics on the market, is a blueprint for various biological and novel treatment regimens that are under investigation today. This review provides a guideline for further irAOP-directed research in immune-mediated hepatotoxicity.

Severe acute liver disease in adults: Contemporary role of histopathology

Liver biopsies have consistently contributed to our understanding of the pathogenesis and aetiologies of acute liver disease. As other diagnostic modalities have been developed and refined, the role of biopsy in the management of patients with acute liver failure (ALF), acute-on-chronic liver failure (ACLF) and acute hepatitis, including acute liver injury (ALI), has changed. Liver biopsy remains particularly valuable when first-line diagnostic algorithms fail to determine aetiology. Despite not being identified as a mandatory diagnostic tool in recent clinical guidelines for the management of ALF or ACLF, many centres continue to undertake biopsies given the relative safety of transjugular biopsy in this setting. Several studies have demonstrated that liver biopsy can provide prognostic information, particularly in the context of so-called indeterminate hepatitis, and is extremely useful in excluding conditions such as metastatic tumours that would preclude transplantation. In addition, its widespread use of percutaneous biopsies in cases of less severe acute liver injury, for example in the establishment of a diagnosis of acute presentation of autoimmune hepatitis or confirmation of a probable or definite drug-induced liver injury (DILI), has meant that many centres have seen a shift in the ratio of specimens they are receiving from patients with chronic to acute liver disease. Histopathologists therefore need to be equipped to deal with these challenging specimens. This overview provides an insight into the contemporary role of biopsies (as well as explant and autopsy material) in diagnosing acute liver disease. It outlines up-to-date clinical definitions of liver injury and considers recent recommendations for the diagnosis of AIH and drug-induced, autoimmune-like hepatitis (DI-AIH).

The role of the microbiome in immune checkpoint inhibitor colitis and hepatitis

Immune checkpoint inhibitors have revolutionised management for a variety of different types of malignancies. However, gastrointestinal adverse effects, in particular colitis and hepatitis, are relatively common with up to 30 % of patients being affected. The gut microbiome has emerged as a potential contributor to both the effectiveness of immune checkpoint inhibitors and their side effects. This review will attempt to examine the impact the microbiome has on adverse effects as a result of immune checkpoint inhibitors as well as the potential for manipulation of the microbiome as a form of management for immune mediated colitis.

Difficulty in differentiating liver injury from an immune checkpoint inhibitor from chemotherapy

This study investigated the potential of immune checkpoint inhibitors (ICIs) combined with chemotherapy as a promising treatment approach for malignancies. This report focuses on a patient with drug-induced liver injury (DILI) following the administration of chemotherapy and ICIs. A 63-year-old patient with non-small cell lung adenocarcinoma (NSCLC) initially underwent γ-knife treatment and subsequently received a combination of chemotherapy comprising bevacizumab and camrelizumab. Due to liver abnormalities, both chemotherapy and ICIs were stopped on day 21. The patient's liver function improved within a month after methylprednisolone treatment. Subsequently, the patient received carboplatin, pemetrexed, and bevacizumab without complications. This finding supported the notion that DILI was likely triggered by the ICI. This case series details a complex instance of DILI resulting from the use of ICIs and pemetrexed/carboplatin. The alignment of the pathological findings and clinical presentation strongly suggested ICI-induced DILI, which was further supported by the definitive response to steroid treatment. This information is important for clinicians, as it emphasizes the importance of closely monitoring liver function and being aware of potential adverse effects associated with ICIs. Such insights contribute to more effective patient care.

Hepatobiliary complications of immune checkpoint inhibitors in cancer

Immune checkpoint inhibitors (ICIs) have dramatically changed the landscape of cancer therapy. Over the last decade, both their primary focus in trials and clinical application have exponentially risen, with repeated demonstrations of their efficacy in improving survival in various cancer types. The adverse effects of these drugs on various organ systems were recognised in early phase studies. Given their relatively new emergence on the market, there has been increasing interest into short- and long-term effects and management of ICIs in real-world settings. ICI-related hepatobiliary toxicities are often challenging to diagnose and difficult to distinguish from other causes of deranged liver biochemical tests. The aim of this review is to provide an up-to-date and detailed exploration of the hepatobiliary complications of ICIs, including pathogenesis and approaches to diagnosis and management.

Establishment of an animal model of immune-related adverse events induced by immune checkpoint inhibitors

OBJECTIVE

Immunotherapy, specifically immune checkpoint inhibitors (ICIs), has revolutionized cancer treatment. However, it can also cause immune-related adverse events (irAEs). This study aimed to develop a clinically practical animal model of irAEs using BALB/c mice.

METHODS

Subcutaneous tumors of mouse breast cancer 4T1 cells were generated in inbred BALB/c mice. The mice were treated with programmed death-1 (PD-1) and cytotoxic t-lymphocyte antigen 4 (CTLA-4) inhibitors once every 3 days for five consecutive administration cycles. Changes in tumor volume and body weight were recorded. Lung computed tomography (CT) scans were conducted. The liver, lungs, heart, and colon tissues of the mice were stained with hematoxylin-eosin (H&E) staining to observe inflammatory infiltration and were scored. Serum samples were collected, and enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of ferritin, glutamic-pyruvic transaminase (ALT), tumor necrosis factor-α (TNF-α), interferon-gamma (IFN-γ), and interleukin-6 (IL-6). Mouse liver and lung cell suspensions were prepared, and changes in macrophages, T cells, myeloid-derived suppressor cells (MDSCs), and regulatory (Treg) cells were detected by flow cytometry.

RESULTS

Mice treated with PD-1 and CTLA-4 inhibitors showed significant reductions in tumor volume and body weight. The tissue inflammatory scores in the experimental group were significantly higher than those in the control group. Lung CT scans of mice in the experimental group showed obvious inflammatory spots. Serum levels of ferritin, IL-6, TNF-α, IFN-γ, and ALT were significantly elevated in the experimental group. Flow cytometry analysis revealed a substantial increase in CD3+T cells, Treg cells, and macrophages in the liver and lung tissues of mice in the experimental group compared with the control group, and the change trend of MDSCs was opposite.

CONCLUSIONS

The irAE-related animal model was successfully established in BALB/c mice using a combination of PD-1 and CTLA-4 inhibitors through multiple administrations with clinical translational value and practical. This model offers valuable insights into irAE mechanisms for further investigation.

Advances in Foxp3+ regulatory T cells (Foxp3+ Treg) and key factors in digestive malignancies

Foxp3+ regulatory T cells (Foxp3+ Treg) play a role in regulating various types of tumors, but uncertainty still exists regarding the exact mechanism underlying Foxp3+ Treg activation in gastrointestinal malignancies. As of now, research has shown that Foxp3+ Treg expression, altered glucose metabolism, or a hypoxic tumor microenvironment all affect Foxp3+ Treg function in the bodies of tumor patients. Furthermore, it has been demonstrated that post-translational modifications are essential for mature Foxp3 to function properly. Additionally, a considerable number of non-coding RNAs (ncRNAs) have been implicated in the activation of the Foxp3 signaling pathway. These mechanisms regulating Foxp3 may one day serve as potential therapeutic targets for gastrointestinal malignancies. This review primarily focuses on the properties and capabilities of Foxp3 and Foxp3+Treg. It emphasizes the advancement of research on the regulatory mechanisms of Foxp3 in different malignant tumors of the digestive system, providing new insights for the exploration of anticancer treatments.

Therapeutic inhibition of monocyte recruitment prevents checkpoint inhibitor-induced hepatitis

BACKGROUND

Checkpoint inhibitor-induced hepatitis (CPI-hepatitis) is an emerging problem with the widening use of CPIs in cancer immunotherapy. Here, we developed a mouse model to characterize the mechanism of CPI-hepatitis and to therapeutically target key pathways driving this pathology.

METHODS

C57BL/6 wild-type (WT) mice were dosed with toll-like receptor (TLR)9 agonist (TLR9-L) for hepatic priming combined with anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) plus anti-programmed cell death 1 (PD-1) ("CPI") or phosphate buffered saline (PBS) control for up to 7 days. Flow cytometry, histology/immunofluorescence and messenger RNA sequencing were used to characterize liver myeloid/lymphoid subsets and inflammation. Hepatocyte damage was assessed by plasma alanine transaminase (ALT) and cytokeratin-18 (CK-18) measurements. In vivo investigations of CPI-hepatitis were carried out in Rag2-/- and Ccr2rfp/rfp transgenic mice, as well as following anti-CD4, anti-CD8 or cenicriviroc (CVC; CCR2/CCR5 antagonist) treatment.

RESULTS

Co-administration of combination CPIs with TLR9-L induced liver pathology closely resembling human disease, with increased infiltration and clustering of granzyme B+perforin+CD8+ T cells and CCR2+ monocytes, 7 days post treatment. This was accompanied by apoptotic hepatocytes surrounding these clusters and elevated ALT and CK-18 plasma levels. Liver RNA sequencing identified key signaling pathways (JAK-STAT, NF-ΚB) and cytokine/chemokine networks (Ifnγ, Cxcl9, Ccl2/Ccr2) as drivers of CPI-hepatitis. Using this model, we show that CD8+ T cells mediate hepatocyte damage in experimental CPI-hepatitis. However, their liver recruitment, clustering, and cytotoxic activity is dependent on the presence of CCR2+ monocytes. The absence of hepatic monocyte recruitment in Ccr2rfp/rfp mice and CCR2 inhibition by CVC treatment in WT mice was able to prevent the development and reverse established experimental CPI-hepatitis.

CONCLUSION

This newly established mouse model provides a platform for in vivo mechanistic studies of CPI-hepatitis. Using this model, we demonstrate the central role of liver infiltrating CCR2+ monocyte interaction with tissue-destructive CD8+ T cells in the pathogenesis of CPI-hepatitis and highlight CCR2 inhibition as a novel therapeutic target.

An algorithm based on immunotherapy discontinuation and liver biopsy spares corticosteroids in two thirds of cases of severe checkpoint inhibitor-induced liver injury

BACKGROUND

There are few data on corticosteroids (CS)-sparing strategies for checkpoint inhibitor (ICI)-induced liver injury (ChILI).

AIM

We aimed to assess the performance of a 2-step algorithm for severe ChILI, based on ICI temporary discontinuation (step-1) and, if lack of biochemical improvement, CS based on the degree of necroinflammation at biopsy (step-2).

METHODS

Prospective study that included all subjects with grade 3/4 ChILI. Peripheral extended immunophenotyping was performed. Indication for CS: severe necroinflammation; mild or moderate necroinflammation with later biochemical worsening.

RESULTS

From 111 subjects with increased transaminases (January 2020 to August 2023), 44 were diagnosed with grade 3 (N = 35) or grade 4 (N = 9) ChILI. Main reason for exclusion was alternative diagnosis. Lung cancer (13) and melanoma (12) were the most common malignancies. ICI: 23(52.3%) anti-PD1, 8(18.2%) anti-PD-L1, 3(6.8%) anti-CTLA-4, 10(22.7%) combined ICI. Liver injury pattern: hepatocellular (23,52.3%) mixed (12,27.3%) and cholestatic (9,20.5%). 14(32%) presented bilirubin >1.2 mg/dL. Overall, 30(68.2%) patients did not require CS: 22(50.0%) due to ICI discontinuation (step-1) and 8/22 (36.4%) based on the degree of necroinflammation (step-2). Biopsy mainly impacted on grade 3 ChILI, sparing CS in 8 out of 15 (53.3%) non-improvement patients after ICI discontinuation. CD8+ HLA-DR expression (p = 0.028), central memory (p = 0.046) were lower in CS-free managed subjects, but effector-memory cells (p = 0.002) were higher. Time to transaminases normalisation was shorter in those CS-free managed (overall: p < 0.001, grade 3: p < 0.001). Considering our results, a strategy based on ICI discontinuation and biopsy for grade 3 ChILI is proposed.

CONCLUSIONS

An algorithm based on temporary immunotherapy discontinuation and biopsy allows CS avoidance in two thirds of cases of severe ChILI.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2% to 40%, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Histologically Proven Recurrent Synovitis after Nivolumab Treatment

A 58-year-old woman with rheumatoid arthritis was diagnosed with methotrexate-associated Hodgkin lymphoma. After receiving several chemotherapy regimens, she started nivolumab treatment. Two weeks later, she was hospitalized with worsening finger, wrist, and elbow joint pain. A synovial biopsy of the wrist joint showed villous synovial proliferation and linear infiltration of CD68-/CD3-positive T cells (with more CD8 than CD4 T cells) but no CD20-positive B cells or CD138-positive macrophages. These findings corresponded to synovitis associated with immune-related adverse events, which are induced mainly by T cells and are different from typical rheumatoid arthritis (RA), in which B cells play a central role.

Immune Checkpoint Inhibitor-induced Pancreatitis with Pancreatic Enlargement Mimicking Autoimmune Pancreatitis: A Case Report and Review of the Literature

A 61-year-old woman was administered 35 cycles of pembrolizumab for the treatment of recurrent endometrial cancer, achieving a complete response. She presented with asymptomatic pancreatic enlargement and elevated hepatobiliary enzymes, but amylase and lipase levels were within the normal ranges. Intrapancreatic bile duct stenosis due to pancreatic enlargement was present, mimicking autoimmune pancreatitis on computed tomography performed before the onset of clinical manifestations. A histological examination of a biopsy specimen showed lymphocyte and plasma cell infiltration with dense fibrosis in the stroma. The patient was successfully treated with oral prednisolone. There were no manifestations of recurrent pancreatitis after tapering the prednisolone dose.

Rapid identification of inflammatory arthritis and associated adverse events following immune checkpoint therapy: a machine learning approach

Introduction

Immune checkpoint inhibitor-induced inflammatory arthritis (ICI-IA) poses a major clinical challenge to ICI therapy for cancer, with 13% of cases halting ICI therapy and ICI-IA being difficult to identify for timely referral to a rheumatologist. The objective of this study was to rapidly identify ICI-IA patients in clinical data and assess associated immune-related adverse events (irAEs) and risk factors.

Methods

We conducted a retrospective study of the electronic health records (EHRs) of 89 patients who developed ICI-IA out of 2451 cancer patients who received ICI therapy at Northwestern University between March 2011 to January 2021. Logistic regression and random forest machine learning models were trained on all EHR diagnoses, labs, medications, and procedures to identify ICI-IA patients and EHR codes indicating ICI-IA. Multivariate logistic regression was then used to test associations between ICI-IA and cancer type, ICI regimen, and comorbid irAEs.

Results

Logistic regression and random forest models identified ICI-IA patients with accuracies of 0.79 and 0.80, respectively. Key EHR features from the random forest model included ICI-IA relevant features (joint pain, steroid prescription, rheumatoid factor tests) and features suggesting comorbid irAEs (thyroid function tests, pruritus, triamcinolone prescription). Compared to 871 adjudicated ICI patients who did not develop arthritis, ICI-IA patients had higher odds of developing cutaneous (odds ratio [OR]=2.66; 95% Confidence Interval [CI] 1.63-4.35), endocrine (OR=2.09; 95% CI 1.15-3.80), or gastrointestinal (OR=2.88; 95% CI 1.76-4.72) irAEs adjusting for demographics, cancer type, and ICI regimen. Melanoma (OR=1.99; 95% CI 1.08-3.65) and renal cell carcinoma (OR=2.03; 95% CI 1.06-3.84) patients were more likely to develop ICI-IA compared to lung cancer patients. Patients on nivolumab+ipilimumab were more likely to develop ICI-IA compared to patients on pembrolizumab (OR=1.86; 95% CI 1.01-3.43).

Discussion

Our machine learning models rapidly identified patients with ICI-IA in EHR data and elucidated clinical features indicative of comorbid irAEs. Patients with ICI-IA were significantly more likely to also develop cutaneous, endocrine, and gastrointestinal irAEs during their clinical course compared to ICI therapy patients without ICI-IA.

Delayed immune-related hepatitis after 24 months of pembrolizumab treatment: a case report and literature review

Immune checkpoint inhibitors targeting the programmed cell death protein 1 (PD-1) pathway have revolutionized cancer immunotherapy by enhancing the immune system's ability to combat cancer cells. However, this innovative approach comes with a distinctive set of challenges, as these therapies can lead to immune-related adverse events (irAEs) due to their mechanism of action. The most common irAEs involve the skin, gastrointestinal tract, liver, endocrine system, and lungs. These events can range from mild skin rashes to severe colitis, pneumonitis, or even autoimmune organ damage. These adverse effects usually appear with an average of 5-15 weeks from the start of treatment depending on the affected organ. This article presents a case report of a delayed related-mediated hepatitis, after 24 months of treatment with pembrolizumab and almost 3 months after its termination, and a review of the scientific literature on cases of delayed immune-related hepatitis caused by anti-PD1. This case highlights the importance of monitoring patients treated with immune checkpoint inhibitors after cessation as a growing number of patients stop treatment due to achieving durable responses.

Updates in the pathogenesis and management of immune-related enterocolitis, hepatitis and cardiovascular toxicities

Immune checkpoint inhibitors (ICIs) have become a cornerstone of treatment for many solid organ malignancies. Alongside increasing use, the occurrence of immune-related adverse events (irAEs) has also increased and remains a significant challenge when treating patients with ICI. The underlying pathophysiology of irAE development for many organ systems is yet to be elucidated, but may involve unmasking of latent autoimmunity, increased T-cell recognition of shared antigens on cancer and normal tissue and ICI-triggered immune dysregulation with overactivation of proinflammatory pathways and suppression of immune control pathways. Management strategies for irAEs have historically been borrowed from paradigms for conventional autoimmune conditions such as inflammatory bowel disease and autoimmune hepatitis; however, recent translational efforts have clearly demonstrated key differences in underlying immune signalling pathways. As we begin to understand these differences, we must adapt a more targeted approach to immunosuppression and exercise a more nuanced approach with the multiple biologic agents available to mitigate ICI-related toxicity without reversing the antitumour effect of ICI. In this review, we focus on three key immune-related toxicities where recent clinical and translational work has provided nuanced insights into pathogenesis and treatment strategies: enterocolitis, hepatitis and cardiovascular toxicity including myocarditis.

Clinical Management of Gastrointestinal and Liver Toxicities of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors have transformed the treatment paradigm for various types of cancer. Nonetheless, with the utilization of these groundbreaking treatments, immune-related adverse events (irAEs) are increasingly encountered. Colonic and hepatic involvement are among the most frequently encountered irAEs. Drug-induced side effects, infectious causes, and tumor-related symptoms are the key differentials for irAE complications. Potential risk factors for the development of irAEs include combination use of immune checkpoint inhibitors, past development of irAEs with other immunotherapy treatments, certain concomitant drugs, and a pre-existing personal or family history of autoimmune illness such as inflammatory bowel disease. The importance of early recognition, timely and proper management cannot be understated, as there are profound clinical implications on the overall cancer treatment plan and prognosis once these adverse events occur. Herein, we cover the clinical management of the well-established gastrointestinal irAEs of enterocolitis and hepatitis, and also provide an overview of several other emerging entities.

The ABC of Immune-Mediated Hepatitis during Immunotherapy in Patients with Cancer: From Pathogenesis to Multidisciplinary Management

Immune-mediated hepatotoxicity (IMH) is not-so-rare complication during treatment with immune checkpoint inhibitors (ICIs). This narrative review aims to report the current knowledge on hepatic immune-related adverse events (irAEs) during immunotherapy from pathogenesis to multidisciplinary management. The majority of cases of IMH are asymptomatic and only a few patients may have clinical conditions. The severity of IMH is usually stratified according to Common Terminology for Clinical Adverse Events (CTCAE) criteria, but these scores may overestimate the clinical severity of IMH compared to the Drug-Induced Liver Injury Network (DILIN) scale. The differential diagnosis of IMH is challenging because the elevated liver enzymes can be due to a number of etiologies such as viral infection, autoimmune and metabolic diseases, liver metastases, biliary diseases, and other drugs. The cornerstones of IMH management are represented by withholding or delaying ICI administration and starting immunosuppressive therapy. A multidisciplinary team, including oncologists, hepatologists, internists, and emergency medicine physicians, is essential for the management of IMH.

HBV reactivation and clinical resolution in an isolated anti-HBc-positive patient during immune checkpoint inhibition

BACKGROUND

Immune checkpoint inhibitor (ICI)-related liver injury is a growing concern as ICIs are increasingly used in cancer treatment regimens. Interestingly, ICIs have exhibited antiviral effects among patients with chronic hepatitis B virus (HBV). However, the underlying mechanisms remain unclear, and clinical data on patients with previous HBV infection/exposure and isolated anti-HBV core antibodies (IAHBcs) are lacking.

METHODS

We report a case illustrating the dual effects of ICIs in a patient experiencing panlobular hepatitis and concurrent HBV reactivation.

FINDINGS

A 68-year-old male patient positive for IAHBcs was admitted with panlobular hepatitis and HBV reactivation after receiving systemic chemotherapy (several months before admission) and ICI treatment (4 weeks before admission) subsequent to metastatic primary lung cancer (NSCLC stage IV). This was followed by a rapid and significant decrease of HBV DNA viral load before and during antiviral treatment.

CONCLUSIONS

This unique case sheds light on the dynamics of ICI therapy in IAHBc-positive patients experiencing HBV reactivation during chemotherapy and underscores the dual impact of ICIs. Moreover, it emphasizes the need for assessment of HBV serology and prophylaxis in IAHBc-positive patients undergoing chemotherapy and ICI treatment.

FUNDING

R.T.C. was supported by the MGH Research Scholars Program.

Morphology of immune-mediated hepatitis: A comparison between immune checkpoint inhibitor therapy and combined immune checkpoint inhibitor/anti-angiogenic therapy

BACKGROUND

The combination of immune checkpoint inhibitors (ICIs) with anti-angiogenic drugs has shown promising anticancer effects. However, ICIs can trigger immune-mediated hepatitis (IMH). We aimed to clarify whether the combined use of anti-angiogenic drugs and ICIs would increase the severity of IMH.

METHODS

One hundred IMH patients (ICI monotherapy vs. ICI plus anti-angiogenic therapy 30 vs. 70) were retrospectively enrolled. Clinicopathological parameters were compared between the two groups.

RESULTS

IMH mainly showed variable degrees of panlobular hepatitis (84 %), while some cases presented mixed cholangio-hepatitic (14 %) or cholangitic (2 %) pattern. The incidence of moderate-severe injury was not significantly different between the two groups (combination vs. monotherapy 38.6 % vs. 20.0 %, p = 0.109). Specifically, the rates of marked lobular injury and portal inflammation were higher in the combination group than in the monotherapy cohort (p < 0.005), while the frequencies of interface hepatitis, bile duct injury, histiocytosis aggregates, and endothelialitis were comparable between the two groups (p > 0.05). Compared to mild IMH cases, severe IMH cases showed higher immunostaining expression levels of PD-L1 (60.7 % vs. 19.4 %, p < 0.0001). Treatments and outcomes of IMH were not significantly different between the two groups (p > 0.05).

CONCLUSIONS

Compared to ICI monotherapy, the administration of anti-angiogenic drugs in combination with ICIs was not associated with increased hepatotoxicity.

Management of liver and gastrointestinal toxicity induced by immune checkpoint inhibitors: Position statement of the AEEH-AEG-SEPD-SEOM-GETECCU

The development of the immune checkpoint inhibitors (ICI) is one of the most remarkable achievements in cancer therapy in recent years. However, their exponential use has led to an increase in immune-related adverse events (irAEs). Gastrointestinal and liver events encompass hepatitis, colitis and upper digestive tract symptoms accounting for the most common irAEs, with incidence rates varying from 2 % to 40 %, the latter in patients undergoing combined ICIs therapy. Based on the current scientific evidence derived from both randomized clinical trials and real-world studies, this statement document provides recommendations on the diagnosis, treatment and prognosis of the gastrointestinal and hepatic ICI-induced adverse events.

Immune-mediated hepatitis: Basic concepts and treatment

Immunotherapy with immune checkpoint inhibitors (ICIs) has revolutionized advanced cancer management. Nevertheless, the generalized use of these medications has led to an increase in the incidence of adverse immune-mediated events and the liver is one of the most frequently affected organs. Liver involvement associated with the administration of immunotherapy is known as immune-mediated hepatitis (IMH), whose incidence and clinical characteristics have been described by different authors. It often presents as mild elevations of amino transferase levels, seen in routine blood tests, that spontaneously return to normal, but it can also manifest as severe transaminitis, possibly leading to the permanent discontinuation of treatment. The aim of the following review was to describe the most up-to-date concepts regarding the epidemiology, diagnosis, risk factors, and progression of IMH, as well as its incidence in different types of common cancers, including hepatocellular carcinoma. Treatment recommendations according to the most current guidelines are also provided.

Immuno-inflammatory in vitro hepatotoxicity models to assess side effects of biologicals exemplified by aldesleukin

Introduction

Hepatotoxicity induced by immunotherapeutics is an appearing cause for immune-mediated drug-induced liver injury. Such immuno-toxic mechanisms are difficult to assess using current preclinical models and the incidence is too low to detect in clinical trials. As hepatotoxicity is a frequent reason for post-authorisation drug withdrawal, there is an urgent need for immuno-inflammatory in vitro models to assess the hepatotoxic potential of immuno-modulatory drug candidates. We developed several immuno-inflammatory hepatotoxicity test systems based on recombinant human interleukin-2 (aldesleukin).

Methods

Co-culture models of primary human CD8+ T cells or NK cells with the hepatocyte cell line HepaRG were established and validated with primary human hepatocytes (PHHs). Subsequently, the HepaRG model was refined by increasing complexity by inclusion of monocyte-derived macrophages (MdMs). The main readouts were cytotoxicity, inflammatory mediator release, surface marker expression and specific hepatocyte functions.

Results

We identified CD8+ T cells as possible mediators of aldesleukin-mediated hepatotoxicity, with MdMs being implicated in increased aldesleukin-induced inflammatory effects. In co-cultures of CD8+ T cells with MdMs and HepaRG cells, cytotoxicity was induced at intermediate/high aldesleukin concentrations and perforin was upregulated. A pro-inflammatory milieu was created measured by interleukin-6 (IL-6), c-reactive protein (CRP), interferon gamma (IFN-γ), and monocyte chemoattractant protein-1 (MCP-1) increase. NK cells responded to aldesleukin, however, only minor aldesleukin-induced cytotoxic effects were measured in co-cultures. Results obtained with HepaRG cells and with PHHs were comparable, especially regarding cytotoxicity, but high inter-donor variations limited meaningfulness of the PHH model.

Discussion

The in vitro test systems developed contribute to the understanding of potential key mechanisms in aldesleukin-mediated hepatotoxicity. In addition, they may aid assessment of immune-mediated hepatotoxicity during the development of novel immunotherapeutics.

Peptide aggregation-induced immunogenic cell death in a breast cancer spheroid model

Utilizing multicellular aggregates (spheroids) for in vitro cancer research offers a physiologically relevant model that closely mirrors the intricate tumor microenvironment, capturing properties of solid tumors such as cell interactions and drug resistance. In this research, we investigated the Peptide-Aggregation Induced Immunogenic Response (PAIIR), an innovative method employing engineered peptides we designed specifically to induce immunogenic cell death (ICD). We contrasted PAIIR-induced ICD with standard ICD and non-ICD inducer chemotherapeutics within the context of three-dimensional breast cancer tumor spheroids. Our findings reveal that PAIIR outperforms traditional chemotherapeutics in its efficacy to stimulate ICD. This is marked by the release of key damage-associated molecular patterns (DAMPs), which bolster the phagocytic clearance of dying cancer cells by dendritic cells (DCs) and, in turn, activate powerful anti-tumor immune responses. Additionally, we observed that PAIIR results in elevated dendritic cell activation and increased antitumor cytokine presence. This study not only showcases the utility of tumor spheroids for efficient high-throughput screening but also emphasizes PAIIR's potential as a formidable immunotherapeutic strategy against breast cancer, setting the stage for deeper exploration and potential clinical implementation.

Immune Checkpoint Inhibitor-Induced Liver Injury

In recent years cancer treatment has been revolutionized by the development and wide application of checkpoint inhibitor (CPI) drugs, which are a form of immunotherapy. CPI treatment is associated with immune-related adverse events, off-target tissue destructive inflammatory complications, which may affect a range of organs, with liver inflammation (hepatitis) being one of the more commonly noted events. This is a novel form of drug-induced liver injury and a rapidly evolving field, as our understanding of both the basic immunopathology of CPI hepatitis (CPI-H) and optimal clinical management, races to catch up with the increasing application of this form of immunotherapy in clinical practice. In this review, we summarize current evidence and understanding of CPI-H, from fundamental immunology to practical patient management.

Effectiveness of tacrolimus in a case of immune checkpoint inhibitor-induced hepatotoxicity that was refractory to steroids and mycophenolate mofetil

Immune checkpoint inhibitors (ICIs) sometimes induce immune-mediated hepatotoxicity (IMH), and corticosteroids and mycophenolate mofetil (MMF) are recommended for the treatment of IMH. However, there is no consensus on the treatment of IMH refractory to these drugs. Here, we report a case of refractory IMH that was successfully treated with tacrolimus. A 69-year-old man presented with liver injury after receiving durvalumab, an ICI, for lung cancer. He was diagnosed with IMH and received corticosteroids including methylprednisolone pulses and MMF, but his liver damage did not improve. Liver histology showed infiltration of inflammatory cells, mainly CD8 + T cells, in the portal area. Tacrolimus was added to corticosteroid and MMF to suppress mainly T cells. After the tacrolimus administration, the liver damage promptly improved. Since IMH is thought to be caused by activated CD8 + T-cell infiltration, T-cell suppression may be an effective treatment. This case suggests that tacrolimus may be an effective option for IMH refractory to corticosteroids or MMF if CD8 + T-cell infiltration is confirmed in the liver tissue.

Efficacy, safety, and biomarker analysis of nivolumab in combination with abemaciclib plus endocrine therapy in patients with HR-positive HER2-negative metastatic breast cancer: a phase II study (WJOG11418B NEWFLAME trial)

BACKGROUND

Hormone receptor (HR)-positive breast cancer is a disease for which no immune checkpoint inhibitors have shown promise as effective therapies. Cyclin-dependent kinase 4 and 6 (CDK4/6) inhibitors synergistically increased the effectiveness of antiprogrammed cell death protein-1 (anti-PD-1)/programmed death-ligand 1 (PD-L1) antibodies in preclinical studies.

METHODS

This non-randomized, multicohort, phase II study evaluated the efficacy and safety of the anti-PD-1 antibody nivolumab 240 mg administered every 2 weeks in combination with the CDK4/6 inhibitor abemaciclib 150 mg twice daily and either fulvestrant (FUL) or letrozole (LET) as a first-line or second-line treatment for HR-positive HER2-negative metastatic breast cancer. The primary end point was the objective response rate (ORR), and secondary end points were toxicity, progression-free survival, and overall survival. Blood, tissue, and fecal samples were collected at multiple points for correlative studies to evaluate immunity biomarkers.

RESULTS

From June 2019 to early study termination due to safety concerns on July 2020, 17 patients were enrolled (FUL: n=12, LET: n=5). One patient with a prior treatment history in the FUL cohort was excluded. ORRs were 54.5% (6/11) and 40.0% (2/5) in the FUL and LET cohorts, respectively. Treatment-emergent (TE) adverse events (AEs) of grade ≥3 occurred in 11 (92%) and 5 (100%) patients in the FUL and LET cohorts, respectively. The most common grade ≥3 TEAEs were neutropenia (7 (58.3%) and 3 (60.0%) in the FUL and LET cohorts, respectively), followed by alanine aminotransferase elevation (5 (41.6%) and 4 (80.0%)). One treatment-related death from interstitial lung disease occurred in the LET cohort. Ten patients developed liver-related grade ≥3 AEs. Liver biopsy specimens from 3 patients showed hepatitis characterized by focal necrosis with predominant CD8+ lymphocyte infiltration. Marked elevation of tumor necrosis factor-related cytokines and interleukin-11, and a decrease in peripheral regulatory T cells (Tregs), were observed in patients with hepatotoxicity. These findings suggest that treatment-related toxicities were immune-related AEs likely caused by proinflammatory cytokine production and suppression of Treg proliferation due to the addition of abemaciclib to nivolumab therapy.

CONCLUSIONS

Although the combination of nivolumab and abemaciclib was active, it caused severe and prolonged immune-related AEs.

TRIAL REGISTRATION NUMBER

JapicCTI-194782, jRCT2080224706, UMIN000036970.

Liver Pathology Related to Onco-Therapeutic Agents

Oncotherapeutic agents can cause a wide range of liver injuries from elevated liver functions tests to fulminant liver failure. In this review, we emphasize a newer generation of drugs including immune checkpoint inhibitors, protein kinase inhibitors, monoclonal antibodies, and hormonal therapy. A few conventional chemotherapy agents are also discussed.

Immune Checkpoint Inhibitor-related Pancreatitis: A Case Series, Review of the Literature and an Expert Opinion

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of various malignancies, but are associated with serious adverse events like pancreatitis. Current guidelines are limited to the first step in treating acute ICI-related pancreatitis with steroids but lack treatment advices for steroid dependent pancreatitis. We describe a case series of 3 patients who developed ICI-related pancreatitis with chronic features such as exocrine insufficiency and pancreatic atrophy at imaging. Our first case developed after treatment with pembrolizumab. The pancreatitis responded well after discontinuation of immunotherapy but imaging showed pancreatic atrophy and exocrine pancreatic insufficiency persisted. Cases 2 and 3 developed after treatment with nivolumab. In both, pancreatitis responded well to steroids. However during steroid tapering, pancreatitis recurred and the latter developed exocrine pancreatic insufficiency and pancreatic atrophy at imaging. Our cases demonstrate resemblances with autoimmune pancreatitis based on clinical and imaging findings. In line, both diseases are T-cell mediated and for autoimmune pancreatitis azathioprine is considered as maintenance therapy. Guidelines of other T-cell mediated diseases like ICI-related hepatitis suggest tacrolimus. After adding tacrolimus in case 2 and azathioprine in case 3, steroids could be completely tapered and no new episodes of pancreatitis have occurred. These findings support the idea that the treatment modalities for other T-cell mediated diseases are worthwhile options for steroid dependent ICI-related pancreatitis.

Nomenclature, diagnosis and management of drug-induced autoimmune-like hepatitis (DI-ALH): An expert opinion meeting report

Drug-induced liver injury (DILI) can mimic almost all other liver disorders. A phenotype increasingly ascribed to drugs is autoimmune-like hepatitis (ALH). This article summarises the major topics discussed at a joint International Conference held between the Drug-Induced Liver Injury consortium and the International Autoimmune Hepatitis Group. DI-ALH is a liver injury with laboratory and/or histological features that may be indistinguishable from those of autoimmune hepatitis (AIH). Previous studies have revealed that patients with DI-ALH and those with idiopathic AIH have very similar clinical, biochemical, immunological and histological features. Differentiating DI-ALH from AIH is important as patients with DI-ALH rarely require long-term immunosuppression and the condition often resolves spontaneously after withdrawal of the implicated drug, whereas patients with AIH mostly require long-term immunosuppression. Therefore, revision of the diagnosis on long-term follow-up may be necessary in some cases. More than 40 different drugs including nitrofurantoin, methyldopa, hydralazine, minocycline, infliximab, herbal and dietary supplements (such as Khat and Tinospora cordifolia) have been implicated in DI-ALH. Understanding of DI-ALH is limited by the lack of specific markers of the disease that could allow for a precise diagnosis, while there is similarly no single feature which is diagnostic of AIH. We propose a management algorithm for patients with liver injury and an autoimmune phenotype. There is an urgent need to prospectively evaluate patients with DI-ALH systematically to enable definitive characterisation of this condition.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

The immune-cell origin of hematologic malignancies provides a unique avenue for the understanding of both the mechanisms of immune responsiveness and immune escape, which has accelerated the progress of immunotherapy. Several categories of immunotherapies have been developed and are being further evaluated in clinical trials for the treatment of blood cancers, including stem cell transplantation, immune checkpoint inhibitors, antigen-targeted antibodies, antibody-drug conjugates, tumor vaccines, and adoptive cell therapies. These immunotherapies have shown the potential to induce long-term remission in refractory or relapsed patients and have led to a paradigm shift in cancer treatment with great clinical success. Different immunotherapeutic approaches have their advantages but also shortcomings that need to be addressed. To provide clinicians with timely information on these revolutionary therapeutic approaches, the comprehensive review provides historical perspectives on the applications and clinical considerations of the immunotherapy. Here, we first outline the recent advances that have been made in the understanding of the various categories of immunotherapies in the treatment of hematologic malignancies. We further discuss the specific mechanisms of action, summarize the clinical trials and outcomes of immunotherapies in hematologic malignancies, as well as the adverse effects and toxicity management and then provide novel insights into challenges and future directions.

Fulminant Liver Failure after Treatment with a Checkpoint Inhibitor for Gastric Cancer: A Case Report and Review of the Literature

Nivolumab is a promising monoclonal antibody inhibitor of programmed death-1, a protein on the surface of T-cells. As such, it is approved for use in patients with multiple advanced malignancies and can significantly elongate progression-free survival. However, monoclonal antibody inhibitors can lead to adverse hepatic reactions, which in rare cases result in further hepatic damage. Herein, we present a case of a patient with locally advanced gastric carcinoma treated with fluorouracil, oxaliplatin, docetaxel and the checkpoint inhibitor nivolumab. Five months after her first dosage of nivolumab and without a preexisting liver disease, she presented with transaminitis. During the course of her stay, the patient developed status epilepticus, which required mechanical ventilation followed by fulminant hepatic failure. A subsequent liver biopsy revealed severe liver damage with extensive confluent parenchymal necrosis corresponding to checkpoint-inhibitor-induced hepatitis. Alternative reasons for this hepatic failure were ruled out. Despite aggressive therapeutic interventions including corticosteroids and plasma exchange, the patient died due to liver failure. Although hepatic failure is rarely seen in patients with checkpoint inhibitor therapy, it requires early awareness and rapid intervention.

Successful treatment of severe immune checkpoint inhibitor associated autoimmune hepatitis with basiliximab: a case report

Immune checkpoint inhibitors (ICIs) targeting programmed cell death-1 (PD-1) and its corresponding ligand PD-L1 are being increasingly used for a wide variety of cancers, including refractory sarcomas. Autoimmune hepatitis is a known side effect of ICIs, and is typically managed with broad, non-specific immunosuppression. Here, we report a case of severe autoimmune hepatitis occurring after anti-PD-1 therapy with nivolumab in a patient with osteosarcoma. Following prolonged unsuccessful treatment with intravenous immunoglobulin, steroids, everolimus, tacrolimus, mycophenolate, and anti-thymoglobulin, the patient was eventually treated with the anti-CD25 monoclonal antibody basiliximab. This resulted in prompt, sustained resolution of her hepatitis without significant side effects. Our case demonstrates that basiliximab may be an effective therapy for steroid-refractory severe ICI-associated hepatitis.

Development and Recovery of Liver Injury in Piglets by Incremental Injection of LPS

This study aimed to explore the effects of the incremental injection of lipopolysaccharide (LPS) on liver histopathology, inflammation, oxidative status, and mitochondrial function in piglets. Forty healthy Duroc × Landrace × Yorkshire castrated boars (21 ± 2 days old, weight 6.84 ± 0.11 kg) were randomly assigned to five groups (n = 8) and then slaughtered on days 0 (group 0, without LPS injection), 1 (group 1), 5 (group 5), 9 (group 9), and 15 (group 15) of LPS injection, respectively. The results showed that, compared to the piglets without LPS injection, LPS injection caused liver injury in the early phase, as manifested by the increased activities of serum liver injury-related parameters (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase, cholinesterase, and total bile acid) on day 1, and impaired liver morphology (disordered hepatic cell cord arrangement, dissolved and vacuolized hepatocytes, karyopycnosis, and inflammatory cell infiltration and congestion) on days 1 and 5. Meanwhile, LPS injection caused liver inflammation, oxidative stress, and mitochondrial dysfunction on days 1 and 5, as reflected by the upregulated mRNA expression of TNF-α, IL-6, IL-1β, TLR4, MyD88, and NF-κB; increased MPO and MDA content; and impaired mitochondrial morphology. However, these parameters were ameliorated in the later phase (days 9~15). Taken together, our data indicate that the incremental injection of the LPS-induced liver injury of piglets could be self-repaired.

Gastrointestinal and Hepatobiliary Immune-related Adverse Events: A Histopathologic Review

Immune checkpoint inhibitors have been increasingly used to treat various malignant neoplasms. Despite their superior efficacy in treating certain ones, their global immune-activation effect leads to systemic side effects, referred to as immune-related adverse events. Immune-related adverse events affect a variety of organs, including the skin, gastrointestinal, hepatobiliary, and endocrine organs. Gastrointestinal tract immune-related adverse events present with a wide range of symptoms with variable severity, which may lead to treatment interruption and administration of immunosuppression therapy in many cases. Histopathologic changes are diverse, overlapping with many other conditions. Therefore, recognizing these changes is crucial in diagnosing immune-related adverse events. This review discusses the pathologic manifestations of gastrointestinal immune-related adverse events and discusses the primary differential diagnoses.

Mortality associated with the development of acute liver failure after a single dose of nivolumab

AIM

Immune-related adverse events (irAEs) caused by immune checkpoint inhibitors are reported in all organs; however, the frequency of liver injury is low compared to irAEs in other organs. We describe a case of fulminant hepatitis after administration of the first dose of nivolumab for the management of esophageal cancer.

METHODS

A man in his 80s was treated with nivolumab as a second-line therapy after his overall health worsened during preoperative chemotherapy for esophageal cancer. He was admitted to the hospital as an emergency case 30 days later with complaints of vomiting, following which acute liver failure was diagnosed.

RESULTS

The patient developed hepatic encephalopathy on the third day after admission and died on the seventh day. The pathological results showed sub-extensive spread hepatocellular necrosis throughout the liver, and immunostaining confirmed the presence of CD8-positive cells, which is consistent with irAEs.

CONCLUSIONS

Immune checkpoint inhibitors have proven to be effective for the treatment of malignant tumors, and although fatalities due to acute liver failure are extremely rare, such cases have been reported previously. Among the immune checkpoint inhibitors, anti-programmed death-1 receptor is associated with less hepatotoxicity. However, even a single dose of this treatment can cause acute liver failure, which could be fatal.

Engineering a HER2-CAR-NK Cell Secreting Soluble Programmed Cell Death Protein with Superior Antitumor Efficacy

A new therapy strategy for relapsing patients who have received trastuzumab treatment urgently needs to be explored. HER2-specific chimeric antigen receptor (CAR)-expressing NK cells are being rapidly developed for solid tumor therapy, as they have many advantages over HER2-CAR-T cells. Endogenous soluble PD-1 (sPD-1) from the PD-1 extracellular domain blocks PD-1/PD-L1 interaction to promote cancer immunology. Herein, we engineered a new HER2-CAR-NK cell that co-expresses sPD-1 (designed as sPD-1-CAR-NK cells) and assessed its cytotoxic activities toward various cancer cells, activation of immunity and sPD-1 release in vitro and in mouse models bearing breast cancer cells with high HER2 expression, with or without trastuzumab resistance. We demonstrated that sPD-1-CAR-NK cells were able to release bioactive sPD-1, thereby enhancing the cytolytic activities of HER2-CAR-NK cells against HER2 and PD-L1 highly expressing target cells accompanied by increases in the secretion of perforin, granzyme B and IFN-γ. In vivo, sPD-1-CAR-NK cells had superior immunological anticancer efficacy compared to HER2-CAR-NK cells, and they had advantages over HER2-CAR-NK cells in the intraperitoneal injection of sPD-1. Moreover, the infiltration and activation of NK and T cells into tumor tissue were increased in mice with sPD-1-CAR-NK cells. There was no significant change in the body temperature, organ tissue and body weight in all groups except for the group with the PD-1 injection. Together, these data indicate that HER2-specific sPD-1-CAR-NK cells can transport sPD-1 into cancer tissues with high HER2 expression, further improving the efficacy of HER-CAR-NK cells without obvious side effects. sPD-1-CAR-NK is a promising cytotherapeutic agent for patients bearing HER2-positive breast cancer, including those with trastuzumab resistance.

An Immunological Perspective on the Mechanism of Drug Induced Liver Injury: Focused on Drugs for Treatment of Hepatocellular Carcinoma and Liver Transplantation

The liver is frequently exposed to potentially toxic materials, and it is the primary site of clearance of foreign agents, along with many innate and adaptive immune cells. Subsequently, drug induced liver injury (DILI), which is caused by medications, herbs, and dietary supplements, often occurs and has become an important issue in liver diseases. Reactive metabolites or drug-protein complexes induce DILI via the activation of various innate and adaptive immune cells. There has been a revolutionary development of treatment drugs for hepatocellular carcinoma (HCC) and liver transplantation (LT), including immune checkpoint inhibitors (ICIs), that show high efficacy in patients with advanced HCC. Along with the high efficacy of novel drugs, DILI has become a pivotal issue in the use of new drugs, including ICIs. This review demonstrates the immunological mechanism of DILI, including the innate and adaptive immune systems. Moreover, it aims to provide drug treatment targets, describe the mechanisms of DILI, and detail the management of DILI caused by drugs for HCC and LT.

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.