Ipilimumab associated hepatitis: imaging and clinicopathologic findings

Review article: Contemporary management of gastrointestinal, pancreatic and hepatic toxicities of immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) are effective oncologic agents which frequently cause immune-related adverse events (irAEs) which can impact multiple organ systems. Onco-Gastroenterology is a novel and emerging subspecialty within gastroenterology focused on cancer treatment-related complications. Gastroenterologists must be prepared to identify and manage diverse immune-mediated toxicities including enterocolitis, hepatitis, pancreatitis and other ICI-induced toxicities.

AIM

To provide a narrative review of the epidemiology, diagnostic evaluation and management of checkpoint inhibitor-induced gastrointestinal and hepatic toxicities.

METHODS

We searched Cochrane and PubMed databases for articles published through August 2023.

RESULTS

Gastrointestinal and hepatic irAEs include most commonly enterocolitis and hepatitis, but also pancreatitis, oesophagitis, gastritis, motility disorders (gastroparesis) and other rarer toxicities. Guidelines from the National Comprehensive Cancer Network, American Society of Clinical Oncology and European Society for Medical Oncology, in combination with emerging cohort and clinical trial data, offer strategies for management of ICI toxicities. Evaluation of irAEs severity by formal classification and clinical stability, and a thorough workup for alternative etiologies which may clinically mimic irAEs underlie initial management. Treatments include corticosteroids, biologics and other immunosuppressive agents plus supportive care; decisions on dosing, timing and choice of steroid adjuncts and potential for subsequent checkpoint inhibitor dosing are nuanced and toxicity-specific.

CONCLUSIONS

Expanding clinical trial and cohort data have clarified the epidemiology and clinical characteristics of gastrointestinal, pancreatic and hepatic toxicities of ICIs. Guidelines, though valuable, remain based principally on retrospective cohort data. Quality prospective, controlled studies may refine algorithms for treatment and potential immunotherapy rechallenge.

Imaging of hepato-pancreato-biliary emergencies in patients with cancer

Hepato-pancreato-biliary (HPB) emergencies in patients with cancer encompass an extensive array of various conditions, including primary malignancies that require prompt treatment, associated severe complications, and life-threatening consequences arising from treatment. In patients with cancer, the liver can be affected by chemotherapy-induced hepatotoxicity, veno-occlusive disease, Budd-Chiari syndrome, liver hemorrhage, and other complications arising from cancer therapy with all these complications requiring timely diagnosis and prompt treament. Cholecystitis induced by systemic anticancer therapies can result in severe conquences if not promptly identified and treated. The application of immunotherapy in cancer therapy is associated with cholangitis. Hemobilia, often caused by medical interventions, may require arterial embolization in patients with severe bleeding and hemodynamic instability. Malignant biliary obstruction in patients with biliary cancers may necessitate palliative strategies such as biliary stenting. In pancreatic cancer, patients often miss surgical treatment due to advanced disease stages or distant metastases, leading to potential emergencies at different treatment phases. This comprehensive review underscores the complexities of diagnostic and treatment roles of medical imaging in managing HPB emergencies in patients with cancer. It illustrates the crucial role of imaging techniques, including magnetic resonance imaging, computed tomography and ultrasound, in diagnosing and managing these conditions for timely intervention. It provides essential insights into the critical nature of early diagnosis and intervention in cancer-related HPB emergencies, ultimately impacting patient outcomes and survival rates.

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.

Epidemiology and Management of Drug-induced Liver Injury: Importance of the Updated RUCAM

Drug-induced liver injury (DILI) is a major cause of acute liver injury, liver failure, and liver transplantation worldwide. In recent years, immune checkpoint inhibitors have become widely used. This has led to an increase in DILI, for which pathophysiology and management methods differ significantly from the past. As the number of cases of acute liver injury and liver transplantation due to DILI is expected to increase, information about a DILI is becoming more valuable. DILI is classified into two types according to its etiology: intrinsic DILI, in which the drug or its metabolites cause liver damage that is dose-dependent and predictable; and idiosyncratic DILI, in which liver damage is also dose-independent but unpredictable. In addition, depending on the course of the disease, chronic DILI or drug-induced autoimmune hepatitis may be present. The number of DILI cases caused by antimicrobial agents is decreasing, whereas that caused by drugs for malignant tumors and health foods is increasing. The Roussel Uclaf Causality Assessment Method is widely used to assess causality in DILI. Liver injury is a type of immune-related adverse event. The pattern of hepatic injury in immune-related adverse events is mostly hepatocellular, but mixed type and bile stasis have also been reported. Sclerosing cholangitis caused by immune checkpoint inhibitors has also been reported as a unique type of injury. Treatment mainly comprises withdrawal of immune checkpoint inhibitors and steroid administration; however, mycophenolate mofetil may be considered if the disease is refractory to steroids.

Tacrolimus for the Management of Delayed Onset and Treatment-Refractory Immune-Related Hepatitis

Immune checkpoint inhibitors, such as pembrolizumab, are effective in the management of metastatic malignancies, such as melanoma, and are associated with a spectrum of immune-related organ toxicities, including immune-related hepatitis (ir-hepatitis). The clinical presentation of ir-hepatitis varies in onset and severity, and management involves immunosuppression with corticosteroids and mycophenolate mofetil as first and second-line agents. Several agents have been proposed as third-line options for treatment-refractory disease. We report the successful use of tacrolimus for delayed onset and treatment-refractory ir-hepatitis secondary to pembrolizumab.

Anlotinib combined with Sintilimab is win-win cooperation for primary squamous cell carcinoma of the thyroid: A case report and literature review

Background

Primary squamous cell carcinoma of the thyroid (PSCCT) is a rare malignant tumor. The incidence rate of PSCCT is less than 1%. However, the diagnosis and treatment of PSCCT are limited. Surgical resection is considered to be one of the few effective intervention methods. In this article, we reported a case of taking tyrosine kinase inhibitors (TKIs) combined with immune checkpoint inhibitors (ICIs) for PSCCT.

Case summary

An 80-year-old male was admitted to our hospital with dyspnea, cough, wheezing, and hoarseness for a giant thyroid mass. He underwent bronchoscopy and tracheal stent implantation to alleviate the respiratory obstruction. Then he accepted right partial thyroid and right lymph node biopsy. Postoperative pathology revealed squamous cell carcinoma. Subsequently, he underwent an endoscopy to exclude upper gastrointestinal squamous cell carcinoma. Finally, he was diagnosed with PSCCT. The patient was tentatively treated with a combination of Anlotinib and Sintilimab. After two courses, the tumor volume significantly reduced in MRI images and shrank further after five courses of combined treatment. Unfortunately, the patient died of fulminant liver failure and autoimmune liver disease after 5-month-treatment.

Conclusion

TKIs combined with ICIs may be an effective and novel way for PSCCT treatment, but immune-related complications, especially liver damage, should be cared.

The radiological appearances of lung cancer treated with immunotherapy

Therapy and prognosis of several solid and hematologic malignancies, including non-small cell lung cancer (NSCLC), have been favourably impacted by the introduction of immune checkpoint inhibitors (ICIs). Their mechanism of action relies on the principle that some cancers can evade immune surveillance by expressing surface inhibitor molecules, known as "immune checkpoints". ICIs aim to conceal tumoural checkpoints on the cell surface and reinvigorate the ability of the host immune system to recognize tumour cells, triggering an antitumoural immune response.In this review, we will focus on the imaging patterns of different responses occurring in patients treated by ICIs. We will also discuss imaging findings of immune-related adverse events (irAEs), along with current and future perspectives of metabolic imaging. Finally, we will explore the role of radiomics in the setting of ICI-treated patients.

Outcomes of immunotherapy-related hepatotoxicity from a multi-disciplinary toxicity team

BACKGROUND

Despite the efficacy of immune checkpoint inhibitors (ICIs), adverse events including hepatotoxicity limit their ongoing use. We investigated the outcomes and management of patients with immune-mediated hepatitis (IMH) and clinical predictors of toxicity resolution.

METHODS

Patients referred to our multidisciplinary immunotherapy-related toxicity group from August 2017 to December 2020 for IMH were evaluated. Toxicity was defined according to CTCAEv4.0. IMH resolution was defined as liver enzyme normalization after steroid initiation.

RESULTS

Thirty-three patients were included in the study, 62% female, and 71% Caucasian. The most common ICI used was PD-1/PD-L1 (76%). Peak IMH occurred at a median of 89 [45,193] days, for which most patients received 1-2 mg/kg/day prednisone equivalent with 35% requiring MMF. Median follow-up was 123 [33,472] days with IMH resolution seen in 48% of patients at a median of 111 [41,214] days. While high-dose steroid use was not associated with IMH resolution, liver enzyme improvement one week after steroids predicted resolution in univariate analysis (p = 0.041). All 11 patients without IMH resolution died from cancer progression or complications with three patients having acute liver failure. Available liver biopsies showed bile duct injury, with varying degrees of portal and lobular inflammation.

CONCLUSION

IMH improvement one week after steroid initiation may predict ultimate IMH resolution.

Immune-mediated hepatitis induced by immune checkpoint inhibitors: Current updates and future perspectives

In recent years, cancer immunotherapy has made remarkable achievements. Immune checkpoint inhibitors (ICIs) have been used successfully in several types of cancer in the past decade. However, expanded indication and increased use of Immune checkpoint inhibitors have resulted in increased reports of toxicity called immune-related adverse events (irAEs). Due to the unique immunological characteristics of the liver, a hepatic immune-related adverse events has also been reported, which is usually termed Immune-mediated hepatitis (IMH). So far, it is generally considered that the mechanism of IMH induced by Immune checkpoint inhibitors is mainly the overactivation of T cells. It has been reported that the incidence of IMH ranges from 1% to 15%. Because of the lack of specific markers, a diagnosis of exclusion of IMH is critical. Although most IMH is mild and recoverable, several death cases have been reported, which has been increasingly concerned. This review summarizes the current understanding of the pathophysiology, epidemiology, diagnosis, management and prognosis of IMH caused by Immune checkpoint inhibitors. It also discusses the controversial issues in IMH, such as the role of liver biopsy, grading criteria, risk factors, rational treatment strategies with steroids, and the timing of Immune checkpoint inhibitors rechallenging, which may provide helpful information for IMH in future clinical practice.

Application of Immune Checkpoint Inhibitors in Gynecological Cancers: What Do Gynecologists Need to Know before Using Immune Checkpoint Inhibitors?

Standard treatments for gynecological cancers include surgery, chemotherapy, and radiation therapy. However, there are limitations associated with the chemotherapeutic drugs used to treat advanced and recurrent gynecological cancers, and it is difficult to identify additional treatments. Therefore, immune checkpoint inhibitor (ICI) therapy products, including PD-1/PD-L1 inhibitors and CTLA-4 inhibitors, are in the spotlight as alternatives for the treatment of advanced gynecological cancers. Although the ICI monotherapy response rate in gynecological cancers is lower than that in melanoma or non-small cell lung cancer, the response rates are approximately 13-52%, 7-22%, and 4-17% for endometrial, ovarian, and cervical cancers, respectively. Several studies are being conducted to compare the outcomes of combining ICI therapy with chemotherapy, radiation therapy, and antiangiogenesis agents. Therefore, it is critical to determine the mechanism underlying ICI therapy-mediated anti-tumor activity and its application in gynecological cancers. Additionally, understanding the possible immune-related adverse events induced post-immunotherapy, as well as the appropriate management of diagnosis and treatment, are necessary to create a quality environment for immunotherapy in patients with gynecological cancers. Therefore, in this review, we summarize the ICI mechanisms, ICIs applied to gynecological cancers, and appropriate diagnosis and treatment of immune-related side effects to help gynecologists treat gynecological cancers using immunotherapy.

Imaging assessment of toxicity related to immune checkpoint inhibitors

In recent years, a wide range of cancer immunotherapies have been developed and have become increasingly important in cancer treatment across multiple oncologic diseases. In particular, immune checkpoint inhibitors (ICIs) offer promising options to improve patient outcomes. However, a major limitation of these treatments consists in the development of immune-related adverse events (irAEs) occurring in potentially any organ system and affecting up to 76% of the patients. The most frequent toxicities involve the skin, gastrointestinal tract, and endocrine system. Although mostly manageable, potentially life-threatening events, particularly due to neuro-, cardiac, and pulmonary toxicity, occur in up to 30% and 55% of the patients treated with ICI-monotherapy or -combination therapy, respectively. Imaging, in particular computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography (¹⁸F-FDG-PET/CT), plays an important role in the detection and characterization of these irAEs. In some patients, irAEs can even be detected on imaging before the onset of clinical symptoms. In this context, it is particularly important to distinguish irAEs from true disease progression and specific immunotherapy related response patterns, such as pseudoprogression. In addition, there are irAEs which might be easily confused with other pathologies such as infection or metastasis. However, many imaging findings, such as in immune-related pneumonitis, are nonspecific. Thus, accurate diagnosis may be delayed underling the importance for adequate imaging features characterization in the appropriate clinical setting in order to provide timely and efficient patient management. ¹⁸F-FDG-PET/CT and radiomics have demonstrated to reliably detect these toxicities and potentially have predictive value for identifying patients at risk of developing irAEs. The purpose of this article is to provide a review of the main immunotherapy-related toxicities and discuss their characteristics on imaging.

Effectiveness of immunosuppressant use for the treatment of immune checkpoint inhibitor-induced liver injury: A systematic review and meta-analysis

Background

Immune-mediated liver injury caused by checkpoint inhibitors (ILICI) is a challenging clinical management issue. Although immunosuppressants are widely used to manage ILICI, no large-scale studies have proved definitive evidence for the most effective form of patient management.

Aim

Analysis of the effectiveness of immunosuppression for immune-related liver injury.

Methods

We performed a systematic review and meta-analysis of the clinical outcomes of immunosuppressive treatment of ILICI patients. A literature search of PubMed, Ovid, and Cochrane Library was completed for dates from 2000 to January 1, 2022. The primary outcome was the response rate to immunosuppressive therapy for ILICI, with subgroup analysis based on the type of cancer, immune checkpoint inhibitor regimen, and severity of liver injury. The secondary outcome was the median time to recovery from ILICI with immunosuppressive therapy.

Results

A total of 30 studies that included 1120 patients were collected. The pooled ILICI response rate was 79% (95% CI 0.73-0.84) for treatment with corticosteroids and 93% (95% CI 0.79-1.0) for treatment with mycophenolate mofetil. For ILICI treated with corticosteroids, the median recovery time was 47.59 (95% CI 39.79-55.40) days compared to 37.74 (95% CI 31.12-44.35) days for all forms of immunosuppression.

Conclusion

Findings support the effectiveness of corticosteroids and mycophenolate mofetil for the treatment of ILICI. The identified median time to recovery is a beneficial guide for patients and physicians, allowing for realistic expectations and appropriate treatment management. Future prospective randomized controlled trials are required to define a standardized management approach to immunosuppressive therapy of ILICI.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022313454.

Immunotherapy and Gastrointestinal Toxicities

Gastrointestinal toxicities secondary to immune checkpoint inhibitors are very frequent. Because in some instances this can be severe or fatal, it is essential to be able to identify immune-related adverse events rapidly. Prompt initiation of systemic immunosuppression can improve outcomes. A biopsy is often necessary to confirm the diagnosis of immune-related adverse events. Moderate or severe irAEs need an interruption of ICI. After the resolution of the toxicities, the rechallenge of immune checkpoint inhibitors must be discussed case by case.

Emerging Trends in Radionuclide Imaging of Infection and Inflammation in Pediatrics: Focus on FDG PET/CT and Immune Reactivity

The most common indication for ¹⁸F-FDG PET/CT is tumor imaging, which may be performed for initial diagnosis, staging, therapeutic response monitoring, surveillance, or suspected recurrence. In the routine practice of pediatric nuclear medicine, most infectious, inflammatory, and autoimmune processes that are detected on ¹⁸F-FDG PET/CT imaging - except for imaging in fever or inflammation of unknown origin - are coincidental and not the main indication for image acquisition. However, interpreting these "coincidental" findings is of utmost importance to avoid erroneously attributing these findings to a neoplastic process. We review the recent literature on fever of unknown origin as well as inflammation of unknown origin in pediatrics and then focus on the ¹⁸F FDG PET/CT imaging findings seen in two specific entities with increased immune reactivity: hemophagocytic lymphohistiocytosis syndrome and the immune-related adverse events associated with checkpoint inhibitors. We will subsequently close with two sections highlighting related topics and relevant references for further reading.

Immune checkpoint inhibitor-related cholangiopathy: Novel clinicopathological description of a multi-centre cohort

BACKGROUND AND AIMS

Cholestatic liver dysfunction is common in immune-related hepatitis (irH) during treatment with immune checkpoint inhibitors (CPI) for malignancy. We investigated the spectrum of bile duct injury and associated natural history in this cohort.

METHOD

Clinical, laboratory, radiological and histopathological data in patients with evidence of bile duct injury during CPI treatment from 2018 to 2020 was collected in three tertiary hospitals.

RESULTS

In this study, ten patients with confirmed bile duct disease were identified. Pembrolizumab was most commonly implicated (8/10). Median CPI cycles prior to bile duct injury was 6. Median alanine aminotransferase and alkaline phosphatase were 225 U/L and 1549 U/L respectively. Clinical jaundice was seen in 6/10 and radiological evidence of bile duct pathology in 8/10. Of five patients, who had liver biopsy, three cases (including two cases with normal MRCP) showed primary sclerosing cholangitis (PSC) like changes with periductal fibrosis. All patients were treated first-line with prednisolone following cessation of CPI, three with mycophenolate mofetil and one with tacrolimus, with clinical response in four patients. Five patients died after a mean follow-up of 27 weeks; cause of death was primarily related to progression of malignancy.

CONCLUSION

Within this heterogeneous cohort, we identified that CPI-related cholangiopathy responded poorly to immunosuppression and potentially progressed to bile duct loss. Thorough radiological and histological assessment is recommended, as identification of the cholangiopathy-associated phenotype may permit more informed advice regarding prognosis. Further data is required to determine detailed immunological characterisation in order to identify individuals at an increased risk of developing cholangiopathy.

Immunotherapy-induced Hepatotoxicity: A Review

Immune checkpoint inhibitors (ICIs) suppress the function of immune checkpoints, which are involved in downregulating immune responses. These lead to an increased activation of the function of T cells, increased release of cytokines, and decreased activity of regulatory T cells. This allows for a more significant and less regulated immune response and subsequent enhanced cytotoxic activity against cancer cells. A number of cancers are now being treated with these agents and this increased use has resulted in more reports of toxicity. While almost every organ can be affected, the skin, gastrointestinal tract, liver, and endocrine glands are most commonly involved. It is necessary that gastroenterologists and hepatologists familiarize themselves with diagnostic steps and management plan in patients with these undesirable outcomes. When assessing for possible ICIs induced hepatotoxicity, it is of utmost importance to use a formal scoring system such as the Roussel Uclaf causality assessment method (RUCAM) to assess for risk factors, alternative causes, and response to cessation and re-exposure of a given drug. While this review is based on studies with and without RUCAM, the conclusions were carefully established mainly from studies that used RUCAM. The aim of this review is to provide information on the epidemiology, risk factors, clinical presentation, diagnostic tools, and management plan based on the most recent studies of immunotherapy-induced hepatotoxicity.

Checkpoint Inhibitor Immune-Related Adverse Events: A Multimodality Pictorial Review

Cancer immunotherapies are drugs that modulate the body's own immune system as an anticancer strategy. Checkpoint inhibitor immunotherapies interfere with cell surface binding proteins that function to promote self-recognition and tolerance, ultimately leading to upregulation of the immune response. Given the striking success of these agents in early trials in melanoma and lung cancer, they have now been studied in many types of cancer and have become a pillar of anticancer therapy for many tumor types. However, abundant upregulation results in a new class of side effects, known as immune-related adverse events (IRAEs). It is critical for the practicing radiologist to be able to recognize these events to best contribute to care for patients on checkpoint inhibitor immunotherapy. Here, we provide a comprehensive system-based review of immune-related adverse events and associated imaging findings. Further, we detail the best imaging modalities for each as well as describe problem solving modalities. Given that IRAEs can be subclinical before becoming clinically apparent, radiologists may be the first provider to recognize them, providing an opportunity for early treatment. Awareness of IRAEs and how to best image them will prepare radiologists to make a meaningful contribution to patient care as part of the clinical team.

Imaging of Immune Checkpoint Inhibitor Immunotherapy for Non-Small Cell Lung Cancer

The normal immune system identifies and eliminates precancerous and cancerous cells. However, tumors can develop immune resistance mechanisms, one of which involves the exploitation of pathways, termed immune checkpoints, that normally suppress T-cell function. The goal of immune checkpoint inhibitor (ICI) immunotherapy is to boost T-cell-mediated immunity to mount a more effective attack on cancer cells. ICIs have changed the treatment landscape of advanced non-small cell lung cancer (NSCLC), and numerous ICIs have now been approved as first-line treatments for NSCLC by the U.S. Food and Drug Administration. ICIs can cause atypical response patterns such as pseudoprogression, whereby the tumor burden initially increases but then decreases. Therefore, response criteria have been developed specifically for patients receiving immunotherapy. Because ICIs activate the immune system, they can lead to inflammatory side effects, termed immune-related adverse events (irAEs). Usually occurring within weeks to months after the start of therapy, irAEs range from asymptomatic abnormal laboratory results to life-threatening conditions such as encephalitis, pneumonitis, myocarditis, hepatitis, and colitis. It is important to be aware of the imaging appearances of the various irAEs to avoid misinterpreting them as metastatic disease, progressive disease, or infection. The basic principles of ICI therapy; indications for ICI therapy in the setting of NSCLC; response assessment and atypical response patterns of ICI therapy, as compared with conventional chemotherapy; and the spectrum of irAEs seen at imaging are reviewed. An invited commentary by Nishino is available online. ^©RSNA, 2022.

Imaging features of toxicities associated with immune checkpoint inhibitors

The past decade has witnessed a change in landscape of cancer management with the advent of precision oncology. Immune checkpoint inhibitors (ICIs) have revolutionized cancer treatment and have played an important role in improving patient survival. While the patients are living longer, treatment with ICIs are sometimes associated with adverse effects, some of which could be fatal. Radiologists can play a crucial role by early identification of some of these adverse effects during restaging scans. Our paper focuses on the imaging features of commonly occurring ICI toxicities based on organ system.

Clinical Significance of Transient Asymptomatic Elevations in Aminotransferase (TAEAT) in Oncology

Monitoring for liver injury remains an important aspect of drug safety assessment, including for oncotherapeutics. When present, drug-induced liver injury may limit the use or result in the discontinuation of these agents. Drug-induced liver injury can exhibit with a wide spectrum of clinical and biochemical manifestations, ranging from transient asymptomatic elevations in aminotransferases (TAEAT) to acute liver failure. Numerous oncotherapeutics have been associated with TAEAT, with published reports indicating a phenomenon in which patients may be asymptomatic without overt liver injury despite the presence of grade ≥3 aminotransferase elevations. In this review, we discuss the occurrence of TAEAT in the context of oncology clinical trials and clinical practice, as well as the clinical relevance of this phenomenon as an adverse event in response to oncotherapeutics and the related cellular and molecular mechanisms that may underlie its occurrence. We also identify several gaps in knowledge relevant to the diagnosis and the management of TAEAT in patients receiving oncotherapeutics, and identify areas warranting further study to enable the future development of consensus guidelines to support clinical decision-making.

Immune-Mediated Hepatitis During Immune Checkpoint Inhibitor cancer Immunotherapy: Lessons From Autoimmune Hepatitis and Liver Immunology

Immune checkpoint inhibitors (ICI) are being increasingly used to successfully treat several types of cancer. However, due to their mode of action, these treatments are associated with several immune-related adverse events (irAEs), including immune-mediated autoimmune-like hepatitis in 5 to 10% of cases. The specific immune mechanism responsible for the development of immune-mediated liver injury caused by immune checkpoint inhibitors (ILICI) is currently unknown. This review summarizes the current knowledge on hepatic irAEs during cancer immunotherapy. It also addresses the clinical management of ILICI and how it is becoming an increasingly important clinical issue. Clinical, histological, and laboratory features of autoimmune hepatitis (AIH) and ILICI are compared, and their shared and distinctive traits are discussed in an effort to better understand the development of hepatic irAEs. Finally, based on the current knowledge of liver immunology and AIH pathogenesis, we propose a series of events that could trigger the observed liver injury in ICI-treated patients. This model could be useful in the design of future studies aiming to identify the specific immune mechanism(s) at play in ILICI and improve immune checkpoint inhibitor cancer immunotherapy.

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.

Immune Checkpoint Inhibitors Induced Hepatotoxicity; Gastroenterologists' Perspectives

BACKGROUND: Immune checkpoint inhibitors (ICIs) have promising clinical activity and are essential medications for patients with several malignancies. However, by deranging the immune system, these novel agents could lead to immune-related adverse events (IRAEs). Hepatotoxicity with checkpoint inhibitors usually results in acute hepatitis or drug-induced liver injury. METHODS: This review article discusses the recent clinical evidence available regarding checkpoint inhibitor-induced hepatitis and reviews an approach to their diagnosis and management. CONCLUSION: ICIs have improved patients' outcomes with different forms of malignancy; however, ICIs-related liver damage is a clinically significant entity in these patients. All patients should be monitored carefully for IRAEs while undergoing treatment with ICIs.

Review of Immune-Related Adverse Events (irAEs) in Non-Small-Cell Lung Cancer (NSCLC)—Their Incidence, Management, Multiorgan irAEs, and Rechallenge

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of advanced malignancies, including non-small cell lung cancer (NSCLC). These agents have improved clinical outcomes and have become quite an attractive alternative alone or combined with other treatments. Although ICIs are tolerated better, they also lead to unique toxicities, termed immune-related adverse events (irAEs). A reconstituted immune system may lead to dysregulation in normal immune self-tolerance and cause inflammatory side effects (irAEs). Although any organ system can be affected, immune-related adverse events most commonly involve the gastrointestinal tract, endocrine glands, skin, and liver. They can occur anytime during the treatment course and rarely even after completion. Owen and colleagues showed that approximately 30% of patients with NSCLC treated with ICIs develop irAEs. Kichenadasse et al. conducted a thorough evaluation of multiorgan irAEs, which is of particular interest because information regarding these types of irAEs is currently sparse. It is important to delineate between infectious etiologies and symptom progression during the management of irAEs. Close consultation with disease-specific subspecialties is encouraged. Corticosteroids are the mainstay of treatment of most irAEs. Early intervention with corticosteroids is crucial in the general management of immune-mediated toxicity. Grade 1–2 irAEs can be closely monitored; hypothyroidism and other endocrine irAEs may be treated with hormone supplementation without the need for corticosteroid therapy. Moderate- to high-dose steroids and other additional immunosuppressants such as tocilizumab and cyclophosphamide might be required in severe, grade 3–4 cases. Recently, increasing research on irAEs after immunotherapy rechallenge has garnered much attention. Dolladille and colleagues assessed the safety in patients with cancer who resumed therapy with the same ICIs and found that rechallenge was associated with about 25–30% of the same irAEs experienced previously (4). However, such data should be carefully considered. Further pooled analyses may be required before we conclude about ICIs’ safety in rechallenge.

The modern therapeutic & imaging landscape of metastatic prostate cancer: a primer for radiologists

Prostate cancer represents one of the leading causes of cancer-related mortality in the United States and the most common cancer among men. Treatment paradigms for the management of advanced stages of prostate cancer have continued to evolve in recent years. These advancements in the therapeutic landscape of metastatic prostate cancer and diagnostic imaging modalities have fundamentally changed the treatment of patients with prostate cancer. In this review article we provide a primer for radiologists highlighting the most recent developments in treatment options and imaging techniques utilized in the modern oncologic management of metastatic prostate cancer. We will examine current therapy options and associated toxicities with an emphasis on relevant imaging findings commonly encountered by radiologists. We also summarize the role of modalities including CT, MRI, PET, bone scintigraphy, and PET in the diagnosis and follow-up of patients with metastatic prostate cancer.

Immunotherapy-Induced Acute Hepatitis in the Elderly: The Case of a Patient with Urothelial Carcinoma and a Review of the Literature

Cancer immunotherapy is an emerging beneficial treatment for cancer that acts by activating the immune system to produce antitumour effects. In particular, immune checkpoint therapy has recently provided novel strategies for cancer treatments. Nevertheless, these new therapeutic approaches have introduced immune-related adverse events to clinical practice. In the elderly, checkpoint inhibitors might have limited efficacy because of immunosenescence. Limited literature data demonstrate a higher incidence of irAEs and an earlier discontinuation of immunotherapy in these patients. We report the case of an 89-year-old male patient with metastatic urothelial carcinoma, who presented with Grade 4 immune-related hepatitis after receiving pembrolizumab treatment.

Hepatobiliary and Pancreatic Adverse Events

The expanded approval of immune checkpoint inhibitors (ICIs) for the treatment of multiple cancer types has offered patients more opportunities in treatment selection and survival.Hepatotoxicity is a well-recognized immune-related adverse event (irAE) associated with treatment with ICI. It is considered a type of drug-induced liver injury (DILI). Depending on the specific ICI and whether the patient receives single- or dual-drug therapy, the incidence of hepatotoxicity in general could be as high as 30%. As more patients receive treatment with ICI, more cases of hepatotoxicity are expected to occur. Clinicians must exercise close pharmacovigilance to recognize liver-related irAEs early.ICI-mediated hepatobiliary toxicity (or "IMH") generally presents as asymptomatic elevations of alanine transaminase and aspartate transaminase, with or without alkaline phosphatase elevation. Some patients may present with jaundice, fever, or malaise. Rarely, it may cause liver failure and death. The diagnosis of IMH is made after careful exclusion of other causes of acute hepatitis based on medical history, laboratory evaluation, imaging, and liver histological findings. In clinically significant cases of IMH, the management involves discontinuation of ICI followed by close monitoring and the initiation of immunosuppression. Current society guidelines, which are not based on robust evidence, specify treatment recommendations depending on the grade of liver injury, according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. However, our clinical experience suggests possible alternatives, including lower corticosteroid dosing with adjunct therapies. Whereas current guidelines endorse permanent cessation of future ICI treatment in patients diagnosed with grades 3-4 IMH, published clinical experience suggests potential for flexibility when assessing for candidacy of resuming ICI.Because histologic bile duct injury has been observed in cases ascribed to IMH, ICI-mediated cholangiopathic disease probably exists on a spectrum within IMH. Even extrahepatic bile duct involvement has been observed. This phenotype warrants special considerations in treatment and surveillance.ICI-related cholecystitis has been rarely reported in the literature. Management follows current standards of care for typical cases of cholecystitis. No relationship with ICI-mediated cholangiopathic disease has been observed.Assessing for and managing ICI-associated pancreatic injury remain challenging to the clinician. Many cases of asymptomatic serum lipase elevation are detected on routine labs without clinical signs or symptoms of typical acute pancreatitis. However, symptomatic patients should be initially managed like traditional cases of acute pancreatitis requiring hospitalization for evaluation and inpatient management.

Pathogenesis of Autoimmune Hepatitis-Cellular and Molecular Mechanisms

Pediatric autoimmune liver disorders include autoimmune hepatitis (AIH), autoimmune sclerosing cholangitis (ASC), and de novo AIH after liver transplantation. AIH is an idiopathic disease characterized by immune-mediated hepatocyte injury associated with the destruction of liver cells, causing inflammation, liver failure, and fibrosis, typically associated with autoantibodies. The etiology of AIH is not entirely unraveled, but evidence supports an intricate interaction among genetic variants, environmental factors, and epigenetic modifications. The pathogenesis of AIH comprises the interaction between specific genetic traits and molecular mimicry for disease development, impaired immunoregulatory mechanisms, including CD4+ T cell population and Treg cells, alongside other contributory roles played by CD8+ cytotoxicity and autoantibody production by B cells. These findings delineate an intricate pathway that includes gene to gene and gene to environment interactions with various drugs, viral infections, and the complex microbiome. Epigenetics emphasizes gene expression through hereditary and reversible modifications of the chromatin architecture without interfering with the DNA sequence. These alterations comprise DNA methylation, histone transformations, and non-coding small (miRNA) and long (lncRNA) RNA transcriptions. The current first-line therapy comprises prednisolone plus azathioprine to induce clinical and biochemical remission. Further understanding of the cellular and molecular mechanisms encountered in AIH may depict their impact on clinical aspects, detect biomarkers, and guide toward novel, effective, and better-targeted therapies with fewer side effects.

Pearls and Pitfalls in the Imaging of Targeted Therapy and Immunotherapy in Lung Cancer

Most lung cancers are diagnosed at advanced stage when the cancer has metastasized outside the lung. These patients are not eligible for curative surgery or radiation therapy and treated with systemic therapy. Advances in the understanding of the biology of lung cancer has resulted in the development of targeted therapy aimed at specific genetic mutations identified with non-small cell lung cancer and immunotherapy that helps the immune system recognize tumors as foreign, stimulates the immune system, and removes the inhibition that allows growth and spread of cancer cells. Tumors treated with targeted or immunotherapies respond differently when compared with traditional chemotherapy and not captured by conventional response criteria such as the World Health Organization criteria and Response Evaluation Criteria in Solid Tumors. Therefore, several modified criteria have been developed to appropriately address the treatment response when using these novel agents. Numerous treatment-related side effects have been described that are important to recognize to avoid misinterpretation as worsening tumor and to ensure appropriate management.

Response criteria for immunotherapy and the radiologic patterns of immune-related adverse events

Immunotherapy has revolutionized clinical outcomes in both early-stage and advanced-stage malignancies. Immunotherapy has improved patient survival in both solid and hematologic disorders with the potential added benefit of less toxicity compared to conventional cytotoxic chemotherapy. Imaging plays a fundamental role in monitoring treatment response and assessment of immune-related adverse events, e.g. pneumonitis, colitis, etc. Familiarity with the current strategies of immune-related response evaluation and their limitations is essential for radiologists to guide clinicians with their treatment decisions. Radiologists should be aware of the wide spectrum of immune-related adverse events and their various radiological features as well as the patterns of treatment response associated with immunotherapies.

Steatosis, Steatohepatitis and Cancer Immunotherapy: An Intricate Story

Immune checkpoint inhibitors represent one of the most significant recent advances in clinical oncology, since they dramatically improved the prognosis of deadly cancers such as melanomas and lung cancer. Treatment with these drugs may be complicated by the occurrence of clinically-relevant adverse drug reactions, most of which are immune-mediated, such as pneumonitis, colitis, endocrinopathies, nephritis, Stevens Johnson syndrome and toxic epidermal necrolysis. Drug-induced steatosis and steatohepatitis are not included among the typical forms of cancer immunotherapy-induced liver toxicity, which, instead, usually occurs as a panlobular hepatitis with prominent lymphocytic infiltrates. Nonetheless, non-alcoholic fatty liver disease is a risk factor for immunotherapy-induced hepatitis, and steatosis and steatohepatitis are frequently observed in this condition. In the present review we discuss how these pathology findings could be explained in the context of current models suggesting immune-mediated pathogenesis for steatohepatitis. We also review evidence suggesting that in patients with hepatocellular carcinoma, the presence of steatosis or steatohepatitis could predict a poor therapeutic response to these agents. How these findings could fit with immune-mediated mechanisms of these liver diseases will also be discussed.

Imaging evaluation of lung cancer treated with PD-1/PD-L1 inhibitors

Immunotherapy (PD-1/PD-L1 inhibitors) has attracted attention for lung cancer treatment and recasted the administration of immunotherapeutics to patients who have advanced/metastatic diseases. Whether in combination or as monotherapy, these medications have become common therapies for certain patients with lung cancer. Moreover, their usage is expected to expand widely in the future. This review aims to discuss the imaging evaluation of lung cancer response to PD-1/PD-L1 therapy with focus on new radiological criteria for immunotherapy response. Abnormal radiological responses (pseudoprogression, dissociative responses, and hyperprogression) and immune-related adverse events are also described.

Review of the recent clinical trials for PD-1/PD-L1 based lung cancer immunotherapy

INTRODUCTION

Lung cancer is known for its high mortality rate and prevalence in the world today. For decades, chemotherapy has been used as the main treatment for this cancer, but this has changed over time. Immune checkpoint inhibitors (ICIs) such as programmed death 1 and programmed death-ligand 1 (PD-1/PD-L1) blocking agents have been assessed in numerous clinical trials as single or combination therapy and have shown overall promising results. Nevertheless, various challenges have been encountered, which cast doubts over this method.

AREAS COVERED

We provide an introduction to the mechanisms underlying the PD-1/PD-L1 pathway. Then, we discuss the latest results from the most leading-edge studies evaluating PD-1/PD-L1 inhibitors in different lines of lung cancer therapy (some of which have gained FDA approval), potential biomarkers, and major challenges of ICI therapy.

EXPERT OPINION

Currently, the standard of care (SoC) for lung cancer consists mostly of chemotherapeutics. With further studies and ongoing trials evaluating novel ICI therapy, FDA has been approving specific ICI therapeutics, including PD-1/PD-L1 inhibitors, for particular types of lung cancer. However, for ICIs to play a key role in SoC, we need to overcome the major challenges of ICI therapy.

Immune checkpoint inhibitor-related hepatotoxicity: A review

The application of immune checkpoint inhibitors (ICI) in advanced cancer has been a major development in the last decade. The indications for ICIs are constantly expanding into new territory across different cancers, disease stages and lines of therapy. With this increased use, adverse events including immune checkpoint inhibitor-related hepatotoxicity (ICH) have emerged as an important clinical problem. This along with the introduction of ICI as first- and second-line treatments for advanced hepatocellular carcinoma makes ICH very relevant to gastroenterologists and hepatologists. The incidence of ICH varies between 1%-20% depending on the number, type and dose of ICI received. Investigation and management generally involve excluding differential diagnoses and following a stepwise escalation of withholding or ceasing ICI, corticosteroid treatment and adding other immunosuppressive agents depending on the severity of toxicity. The majority of patients with ICH recover and some may even safely recommence ICI therapy. Guideline recommendations are largely based on evidence derived from retrospective case series which highlights a priority for future research.

Post-immunotherapy imaging in lung cancer

By boosting the immune system, immunotherapy with immune checkpoint inhibitors (ICIs) has altered the management of patients with various cancers including those with metastatic non-small cell lung cancer (NSCLC). As a result of immune system activation, ICIs are associated with unique response patterns (that are not addressed by traditional response criteria) and inflammatory side effects termed immune-related adverse events. In this article, we will review the role of immunotherapy in cancer treatment, specifically ICIs used in NSCLC treatment, radiological response criteria of immunotherapy, and the imaging spectrum of immune-related adverse events.

Managing toxicities associated with immune checkpoint inhibitors

ABSTRACT

Recent development of immunotherapy has led to remarkable advancement in cancer therapy. Drugs that inhibit the cytotoxic T-lymphocyte-associated protein (CTLA-4) and programmed death-1 (PD-1) immune checkpoint pathways have shown improved patient survival. However, by altering the immune response to fight cancer, a new class of adverse reactions has emerged, known as immune-related adverse events. These adverse events are due to overactivation of the immune system in almost any organ of the body, can occur at any point in a patient's treatment course, and may become life-threatening. This article describes how to promptly recognize and manage these toxicities.

CT, MRI and PET/CT features of abdominal manifestations of cutaneous melanoma: a review of current concepts in the era of tumor-specific therapies

Abdominal manifestations in patients with cutaneous melanoma include involvement due to metastatic spread and immune checkpoint inhibitor induced adverse events. The purpose of this review is to provide a critical overview of abdominal manifestations in patients with cutaneous melanoma and highlight the current imaging challenges in the era of tumor-specific therapies. Immune checkpoint inhibitors represent a treatment with demonstrated efficacy in the treatment of advanced cutaneous melanoma but are associated with several abdominal adverse events that must be recognized. CT has a role in the identification of colitis, enteritis and pancreatitis, whereas MRI has an important role in the diagnosis of autoimmune pancreatitis. Current evidence demonstrates that MRI should be the preferred imaging technique for the detection and characterization of hepatic and splenic metastases from cutaneous melanoma. The role of ¹⁸F-FDG-PET/CT should be further evaluated but current literature suggests an efficacy in the detection of pancreatic metastases not seen on CT and MRI.

Immune-Mediated Drug-Induced Liver Injury: Immunogenetics and Experimental Models

Drug-induced liver injury (DILI) is a challenging clinical event in medicine, particularly because of its ability to present with a variety of phenotypes including that of autoimmune hepatitis or other immune mediated liver injuries. Limited diagnostic and therapeutic tools are available, mostly because its pathogenesis has remained poorly understood for decades. The recent scientific and technological advancements in genomics and immunology are paving the way for a better understanding of the molecular aspects of DILI. This review provides an updated overview of the genetic predisposition and immunological mechanisms behind the pathogenesis of DILI and presents the state-of-the-art experimental models to study DILI at the pre-clinical level.

Fatal immune-related hepatitis with intrahepatic cholestasis and pneumonia associated with camrelizumab: A case report and literature review

Camrelizumab (SHR-1210), a human monoclonal antibody against programmed death receptor 1 (PD-1), blocks the binding of PD-1 to PD-L1, consequently inhibiting immune system evasion by tumor cells. A 65-year-old man underwent radical esophagectomy 5 months ago following the diagnosis of esophageal cancer by gastroscopy. Approximately 40 days later, capecitabine was administered at a dosage of 1.5 g Po bid for 14 days, and anti-PD-1 (camrelizumab 200 mg) was administered twice. Around 20 days later, abnormal liver function was detected. He received a diagnosis of drug-induced liver injury. Chest computed tomography scanning revealed interstitial inflammatory lesions in both lower lungs. Liver biopsy revealed immune injury with ductopenia. Therefore, the diagnosis was revised as immune-related pneumonia and hepatitis associated with camrelizumab. The treatment regimen of methylprednisolone was adjusted to 40 mg/day and gradually increased to 80 mg/day. Mycophenolate mofetil was administered at a dose of 2 g/day. Consequently, chest tightness and shortness of breath resolved, and pulmonary inflammation improved. However, jaundice did not improve and continued to exacerbate. The last measured prothrombin time was 41 s, prothrombin activity was 19%, and the international normalized ratio was 4.03. The cause of death was diagnosed as liver failure, cardiopulmonary failure, and septic shock.

Severe immune-related hepatitis induced by immune checkpoint inhibitors: Clinical features and management proposal

BACKGROUND

Immune-related hepatitis (IRH) occurs in 1 to 18% of immune checkpoint inhibitor (ICI)-treated patients. Steroids are usually recommended for grade≥3 IRH, but their impact on IRH resolution and patient survival remains unclear.

METHODS

We retrospectively analyzed a prospective cohort of 339 patients treated at Saint-Louis Hospital (Paris, France) with ICIs for advanced melanoma. Cases of grade≥3 IRH were collected and analyzed. Two groups were compared for their biological features and time for IRH resolution and survival: patients who received steroids (steroids group: SG) and patients who did not (nonsteroids group: NSG).

FINDINGS

Grade≥3 IRH was observed in 21 patients. Thirteen were treated with steroids (SG), and 8 were not (NSG). The median time for toxicity resolution was 49 days in SG and 24 days in NSG (P=0.62). All but one patient showed a favorable outcome. Two-year survival was 56% in SG and 54% in NSG (P=0.83). Higher transaminase (P=0.002) and bilirubin (P=0.008) and lower prothrombin (P=0.035) levels were observed in SG than in NSG. For 8 (4 SG/4 NSG) patients, ICI was resumed without any hepatitis relapse.

INTERPRETATION

Favorable outcomes may be achieved spontaneously and with no steroids in patients with severe IRH. Steroid initiation should be discussed in cases of high bilirubin levels and decreased prothrombin levels. ICI could be resumed without hepatitis relapse. We propose a management algorithm for grade≥3 IRH that should be validated in larger and prospective cohorts.

Checkpoint inhibitor induced hepatitis and the relation with liver metastasis and outcome in advanced melanoma patients

Background

Checkpoint inhibitor-induced hepatitis is an immune-related adverse event of programmed cell death protein 1 (PD-1) inhibition, cytotoxic T-lymphocyte associated 4 (CTLA-4) inhibition or the combination of both. Aim of this study was to assess whether checkpoint inhibitor-induced hepatitis is related to liver metastasis and outcome in a real-world nationwide cohort.

Methods

Data from the prospective nationwide Dutch Melanoma Treatment Registry (DMTR) was used to analyze incidence, risk factors of checkpoint inhibitor-induced grade 3–4 hepatitis and outcome.

Results

2561 advanced cutaneous melanoma patients received 3111 treatments with checkpoint inhibitors between May 2012 and January 2019. Severe hepatitis occurred in 30/1620 (1.8%) patients treated with PD-1 inhibitors, in 29/1105 (2.6%) patients treated with ipilimumab and in 80/386 (20.7%) patients treated with combination therapy. Patients with hepatitis had a similar prevalence of liver metastasis compared to patients without hepatitis (32% vs. 27%; p = 0.58 for PD-1 inhibitors; 42% vs. 29%; p = 0.16 for ipilimumab; 38% vs. 43%; p = 0.50 for combination therapy). There was no difference in median progression free and overall survival between patients with and without hepatitis (6.0 months vs. 5.4 months progression-free survival; p = 0.61; 17.0 vs. 16.2 months overall survival; p = 0.44).

Conclusion

Incidence of hepatitis in a real-world cohort is 1.8% for PD-1 inhibitor, 2.6% for ipilimumab and 20.7% for combination therapy. Checkpoint inhibitor-induced hepatitis had no relation with liver metastasis and had no negative effect on the outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12072-021-10151-4.

Very Delayed Acute Hepatitis after Pembrolizumab Therapy for Advanced Malignancy: How Long Should We Watch?

Immune checkpoint inhibitors (ICIs) have led to major therapeutic advances in the management of malignancy. Despite promising outcomes for some cancers, ICIs are linked to unique side-effects known as immune-related adverse events (IrAEs). These may affect a wide array of organ systems. In particular, ICI-induced hepatitis is diagnostically challenging given its variable natural history and clinical manifestations. The onset of ICI-induced hepatitis often occurs between 6 and 14 weeks after treatment initiation and rarely exhibits delayed presentations or manifests after treatment cessation. We present a case of very delayed-onset ICI-induced hepatitis, stressing the importance of long-term surveillance for immune-indued hepatitis in patients initiated on ICIs even long after treatment cessation.

Abdominal immune-related adverse events: detection on ultrasonography, CT, MRI and 18F-Fluorodeoxyglucose positron emission tomography

Immune checkpoint inhibitor and chimeric antigen receptor T-cell therapies are associated with a unique spectrum of complications termed immune-related adverse events (irAEs). The abdomen is the most frequent site of severe irAEs that require hospitalization with life-threatening consequences. Most abdominal irAEs such as enterocolitis, hepatitis, cholangiopathy, cholecystitis, pancreatitis, adrenalitis, and sarcoid-like reaction are initially detected on imaging such as ultrasonography (US), CT, MRI and fusion 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)-CT during routine surveillance of cancer therapy. Early recognition and diagnosis of irAEs and immediate management with cessation of immune modulator cancer therapy and institution of immunosuppressive therapy are necessary to avert morbidity and mortality. Diagnosis of irAEs is confirmed by tissue sampling or by follow-up imaging demonstrating resolution. Abdominal radiologists reviewing imaging on patients being treated with anti-cancer immunomodulators should be familiar with the imaging manifestations of irAEs.

Gastrointestinal adverse events of immunotherapy

Cancer immunotherapy with immune-checkpoint inhibitors (ICIs) has emerged as an effective treatment for different types of cancer. ICIs are monoclonal antibodies that inhibit the signaling pathway that suppress antitumor T-cell activity. Patients benefit from increased overall and progression-free survival, but the enhancement of normal immunity can result in autoimmune manifestations, called immune-related adverse events (IRAEs), which may lead to a discontinuation of cancer therapy and to severe also life-threating events. IRAEs may affect any organs or system in the human body, being the gastrointestinal (GI) tract one of the most involved districts. Imaging plays an important role in recognizing GI IRAEs and radiologist should be familiar with the main spectrum of radiological appearance. Indeed, early detection of GI IRAEs is crucial for proper patient management and reduces morbidity and mortality. The purpose of this review is to present the most relevant imaging manifestation of GI IRAEs.

Imaging spectrum of adverse events of immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs), a form of immunotherapy, are increasingly used for a variety of malignancies and have been linked to numerous treatment-related side effects known as immune-related adverse events (irAEs). IrAEs can affect multiple organ systems and are important to recognise in order to avoid misinterpretation as progressive tumour and to ensure appropriate management. In this pictorial review, we will briefly discuss radiological response criteria of immunotherapy and describe the imaging appearances of the wide spectrum of these ICI-associated toxicities.

Acute cytokine release syndrome after a first dose of pembrolizumab as second-line treatment for metastatic, programmed death-ligand 1-positive, non-small-cell lung cancer

INTRODUCTION

The use of programmed death-ligand 1 (PD-L1) checkpoint inhibitor therapy is expanding, although its adverse effects are not completely known. We report on a rare case of acute cytokine release syndrome related to pembrolizumab use in a patient with lung cancer.

CASE REPORT

A 79-year-old man with metastatic, PD-L1-positive, non-small-cell lung cancer developed a febrile condition associated with a systemic inflammatory response syndrome and suffered haemodynamic compromise four hours after the first intravenous administration of pembrolizumab. A thorough medical workup found no alternative cause and a grade 2 cytokine release syndrome (CRS) was diagnosed.Management and outcome: Aggressive fluid resuscitation and supportive therapy led to restitutio ad integrum.

DISCUSSION

Acute CRS after the administration of a PD-L1 inhibitor is infrequent but could be a fatal condition. Supportive treatment and, if necessary, corticosteroids should be considered.

Novel human immunomodulatory T cell receptors and their double-edged potential in autoimmunity, cardiovascular disease and cancer

In the last decade, approaches based on T cells and their immunomodulatory receptors have emerged as a solid improvement in treatments for various types of cancer. However, the roles of these molecules in the therapeutic context of autoimmune and cardiovascular diseases are still relatively unexplored. Here, we review the best known and most commonly used immunomodulatory T cell receptors in clinical practice (PD-1 and CTLA-4), along with the rest of the receptors with known functions in animal models, which have great potential as modulators in human pathologies in the medium term. Among these other receptors is the receptor CD69, which has recently been described to be expressed in mouse and human T cells in autoimmune and cardiovascular diseases and cancer. However, inhibition of these receptors individually or in combination by drugs or monoclonal antibodies generates a loss of immunological tolerance and can trigger multiple autoimmune disorders in different organs and immune-related adverse effects. In the coming decades, knowledge on the functions of different immunomodulatory receptors will be pivotal for the development of new and better therapies with less harmful side effects. In this review, we discuss the roles of these receptors in the control of immunity from a perspective focused on therapeutic potential in not only cancer but also autoimmune diseases, such as systemic lupus erythematosus, autoimmune diabetes and rheumatoid arthritis, and cardiovascular diseases, such as atherosclerosis, acute myocardial infarction, and myocarditis.

Pembrolizumab-Induced Immune-Mediated Hepatitis and Concurrent Hepatitis B Reactivation in a Patient With Non-Small Cell Lung Cancer

New immuno-therapeutic agents like pembrolizumab used in cancer treatment are known to cause immune-mediated hepatitis. Most of these cases are straightforward when the onset of transaminitis correlates with the introduction of the medication. This agent causing hepatitis B reactivation has been reported only once. To have both these adverse effects occurring at the same time in a patient is uncommon and presents a clinical challenge. Our patient was a 49-year-old gentleman diagnosed with metastatic adenocarcinoma of the lung seven months ago. He was started on pembrolizumab, as the malignant tissue obtained during biopsy had high program death-ligand 1 (PDL1) expression. On reviewing the labs ordered during the time of cancer diagnosis, this man has evidence of chronic hepatitis B with positive hepatitis B surface antigen and positive hepatitis B core immunoglobulin G (IgG) antibody. He presented with acute hepatitis, and workup showed features of hepatitis B reactivation, but the extent of reactivation was not adequate to explain the presentation, hence investigations were pursued. This led the way to the diagnosis of a combined hepatitis B reactivation and drug-induced immune hepatitis in this case. He responded promptly to the withdrawal of the agent and steroids. On follow-up, his liver function panel had significantly improved.  This case is very unique in two aspects. First, to our knowledge, there is only one case reported of pembrolizumab-induced hepatitis B reactivation. In addition, our patient also had immune-mediated hepatitis induced by pembrolizumab. It is very rare to have a combination of these two presentations to be seen in a patient at the same time. Pembrolizumab-induced immune hepatitis can coexist with hepatitis B reactivation following therapy with this agent.