Importance of endoscopic and histological evaluation in the management of immune checkpoint inhibitor-induced colitis

Identification and impact of microbiota-derived metabolites in ascites of ovarian and gastrointestinal cancer

BACKGROUND

Malignant ascites is a common complication of advanced ovarian cancer (OC) and gastrointestinal cancer (GI), significantly impacting metastasis, quality of life, and survival. Increased intestinal permeability can lead to blood or lymphatic infiltration and microbial translocation from the gastrointestinal or uterine tract. This study aimed to identify microbiota-derived metabolites in ascites from OC (stages II-III and IV) and GI patients, assessing their roles in tumor progression.

METHODS

Malignant ascites samples from 18 OC and GI patients were analyzed using a four-dimensional (4D) untargeted metabolomics approach combining reversed-phase (RP) and hydrophilic interaction liquid chromatography (HILIC) with trapped ion mobility spectrometry time-of-flight mass spectrometry (timsTOF-MS). Additonally, a targeted flow cytometry-based cytokine panel was used to screen for inflammatory markers. Non-endogenous, microbiota-derived metabolites were identified through the Human Microbial Metabolome Database (MiMeDB).

RESULTS

OC stage IV exhibited metabolic profiles similar to GI cancers, while OC stage II-III differed significantly. Stage IV OC patients exhibited higher levels of 11 typically microbiome-derived metabolites, including 1-methylhistidine, 3-hydroxyanthranilic acid, 4-pyridoxic acid, biliverdin, butyryl-L-carnitine, hydroxypropionic acid, indole, lysophosphatidylinositol 18:1 (LPI 18:1), mevalonic acid, N-acetyl-L-phenylalanine, and nudifloramide, and lower levels of 5 metabolites, including benzyl alcohol, naringenin, o-cresol, octadecanedioic acid, and phenol, compared to stage II-III. Correlation analysis revealed positive associations between IL-10 and metabolites such as glucosamine and LPCs, while MCP-1 positively correlated with benzyl alcohol and phenol.

CONCLUSION

4D metabolomics revealed distinct metabolic signatures in OC and GI ascites, highlighting microbiota-derived metabolites involved in lipid metabolism and inflammation. Metabolites like 3-hydroxyanthranilic acid, indole, and naringenin may serve as markers of disease progression and underscore the microbiota's role in shaping malignant ascites and tumor biology.

Pathological characteristics of inflammatory bowel diseases

Inflammatory bowel disease (IBD) is an inflammatory disorder in which intestinal homeostasis is disrupted for some reason. Among them, ulcerative colitis (UC) and Crohn's disease (CD) are frequently referred to as IBD in the narrow sense, characterized by relapse episodes and remission periods. The differential diagnosis of IBD involves a broad spectrum of inflammatory or infectious diseases that mimic UC and/or CD, as well as others that may complicate existing IBD. Accordingly, these differential diseases and modifying factors should be considered in their pathological diagnosis, and a careful diagnosis should be made in close collaboration with clinicians. Here, we provide a pathological overview of UC, CD, and their differential diseases, as well as IBD-associated cancers, demonstrating their typical gross and histological features. Further, we introduce a pathological scoring system for biopsy specimens to diagnose IBD that may potentially be integrated into clinical practice.

Differential Disease Behavior of Immune-Mediated Colitis Among Different Types of Immune Checkpoint Inhibition

BACKGROUND

Immune-checkpoint inhibitors (ICIs) enhance the immune response against cancer but can cause immune-related adverse events, with immune-mediated colitis (IMC) being among the most common.

OBJECTIVE

We investigated variations in gastrointestinal disease behavior and outcomes among patients receiving different ICI regimens.

METHODS

This retrospective chart review included patients who received ICIs and developed IMC. Groups were categorized by their last ICI regimen before IMC onset into either programmed cell death protein-1/ligand-1 monotherapy or cytotoxic T-lymphocyte antigen 4 (CTLA-4) monotherapy/combination immunotherapy. Demographic and IMC-related clinical information was collected.

RESULTS

There were 414 patients included in this study: 169 treated with programmed cell death protein-1/ligand-1 monotherapy and 245 treated with CTLA-4 mono/combination therapy. Patients treated with CTLA-4 therapy had an earlier onset of IMC (median 46 days vs 123 days, p < 0.001). They were more likely to present with fever (p = 0.02), abdominal pain (p = 0.049), or hematochezia (p < 0.001). They also had more severe colitis with 47.3% of patients in the CTLA-4 group presenting with grade ≥3 colitis versus 20.2% in the programmed cell death protein-1/ligand-1 group (p < 0.05). On endoscopy, CTLA-4 mono/combination therapy was associated with increased ulcerative findings (24.4 vs 8.4%, p = 0.002). On histology, the programmed cell death protein-1/ligand-1 group was more likely to have microscopic colitis (13.9 vs 5.8%, p < 0.045).

CONCLUSIONS

This study provides insight into the effect of ICI type on IMC disease course. Cytotoxic T-lymphocyte antigen 4 inhibition leads to an earlier and more severe IMC onset with distinct endoscopic and histologic features. Further research is needed to refine treatment algorithms and identify the mechanisms underlying the variability in IMC presentation among different ICI regimens.

Gastrointestinal toxicities associated with immune checkpoint inhibitors therapy: risks and management

Immune checkpoint inhibitors (ICIs) have greatly improved cancer treatment by boosting the immune system's ability to target tumors. However, they can also cause serious side effects, particularly in the digestive system. These include immune-related diarrhea, inflammation of the intestines and, less commonly, inflammation of the stomach or esophagus. This review underscores the importance of early detection, accurate diagnosis, and timely treatment to improve patient outcomes. It also highlights the need for further research to develop strategies to reduce gastrointestinal toxicities and enhance the overall effectiveness of ICIs in cancer therapy.

Early identification and multidisciplinary management of immune checkpoint inhibitors associated colitis can improve patient outcomes

Currently, the use of immune checkpoint inhibitors (ICIs) has shown notable clinical efficacy in treating various malignant tumors, significantly improving patient prognosis. However, while ICIs enhance the body's anti-tumor effects, they can also trigger immune-related adverse events (irAEs), with ICI-associated colitis being one of the more prevalent forms. This condition can disrupt treatment, necessitate drug discontinuation, and adversely affect therapeutic outcomes. In severe cases, irAEs may even become life-threatening. A recent case report by Hong et al highlights the importance of vigilance for ICI-associated colitis in patients experiencing symptoms such as diarrhea and abdominal pain, which can arise both during and even after completion of ICI treatment. Early identification, multidisciplinary management, and continuous monitoring of patients are essential steps to further improve outcomes.

Predictive Value of FDG Uptake on PET for Future Immune Checkpoint Inhibitor-Mediated Colitis: A Case Series

Objectives: Immune-mediated colitis (IMC) is a common immune-related adverse event during immune checkpoint inhibitor (ICI) therapy. This case series and review aimed to highlight atypical cases of IMC and explore the potential of PET/CT to predict imminent ICI colitis. Methods: Through a descriptive, retrospective study at a tertiary cancer center, we identified adult patients receiving ICIs for any cancer between 2010 and 2022 who also underwent PET/CT for routine cancer surveillance during this time. We included patients who had signs and symptoms of colitis and reviewed their surveillance PET/CT scans obtained 2 to 6 weeks before and up to 3 months after diagnosis. Results: For the 33 included patients, surveillance scans were reviewed in collaboration with a nuclear radiologist. A total of 17 patients (51.5%) received combination therapy, while 14 (42.4%) received anti-PD-1/PD-L1 monotherapy. While ICI therapy has a median duration of 6.5 months, most patients (72.7%) had negative surveillance PET/CT for colitis. Diarrhea and colitis severity were similar among those with positive and negative findings for colitis on surveillance PET/CT. The outcomes of colitis were similar, with an 81.8% resolution in patients with negative PET/CT and 71.4% in patients with positive PET/CT. Conclusions: PET/CT imaging did not appear to assist in predicting IMC. This may be due to the long interval between clinical IMC and surveillance PET/CT imaging. The continued use of clinical criteria combined with laboratory markers, e.g., lactoferrin and calprotectin, and endoscopy/histology will enable more accurate detection and timely treatment of IMC.

Treatment of immune checkpoint inhibitor-related colitis: a narrative review

Background and Objective

Cancer is one of the most difficult diseases facing modern medicine, and increasing amounts of research and clinical treatments are being applied to the treatment of cancer. Immunotherapy, particularly immune checkpoint inhibitor (ICI) therapy, has revolutionized the treatment and overall survival of patients with several different types of cancer. Approximately one-third of patients treated with ICIs may experience immune-related adverse events (irAEs). Immune checkpoint inhibitor-associated colitis (ICIC) is the most common irAE with an incidence of approximately 8-10%, ICIC usually presents as watery or bloody diarrhea, and if the symptoms are severe, ICI treatment must be interrupted or even terminated. This review summarizes the epidemiology, pathogenesis, clinical characteristics, and therapies of ICIC, focusing on the use of biologics, in order to propose treatment options in different situations to control immune checkpoint inhibitor-related colitis as soon as possible.

Methods

To find relevant articles for this narrative review paper, a combination of keywords such as immune checkpoint inhibitor-related colitis, corticosteroids, biologics were searched for in PubMed databases.

Key Content and Findings

The pathogenesis of ICIC is complex and primarily involves antitumor effects and indirect damage to colonic tissues, as well as the activation of specific proinflammatory pathways. Corticosteroids (CSs) are the first line of treatment for ICIC, but steroid-refractory or steroid-resistant cases often occur. Patients with irAE colitis respond favorably to biologics, and patients with CS-resistant/refractory enterocolitis can benefit from the early use of biologics.

Conclusions

Biologics are currently recommended for the treatment of ICIC but are usually used as a supplement after the failure of first-line CS therapy. Patients with irAE colitis respond favorably to biologics, and patients with CS-resistant/refractory enterocolitis can benefit from the early use of biologics. Biologics (alone or in combination with CS) should be considered as an early therapy option for high-risk patients rather than just an escalation after a failure to respond to CS.

CD8+ cell dominance in immune checkpoint inhibitor-induced colitis and its heterogeneity across endoscopic features

Background

Immune checkpoint inhibitor (ICI)-induced colitis is a significant adverse event associated with ICI therapy, known to be linked to increased cytotoxic T-cell activity.

Objectives

To compare T-cell subsets based on the endoscopic features of ICI-induced colitis and to compare these findings with those of inflammatory bowel disease (IBD).

Design

Prospective cohort study.

Methods

We analyzed patients with ICI-induced colitis, confirmed through both endoscopic and histological evaluation. Biopsy specimens were examined using multiplex immunohistochemistry to assess their immune cell profile. Clinical outcomes were analyzed. Immune cell profiles were compared based on their endoscopic features and contrasted with those of patients with IBD.

Results

Seventeen patients with ICI-induced colitis were included in the study. All patients showed clinical improvement after treatment, and steroids were administered to 11 patients (64.7%). Based on endoscopic features, the patients were classified as Crohn's disease (CD)-like (n = 3, 17.6%), ulcerative colitis (UC)-like (n = 9, 52.9%), or microscopic colitis (MC)-like (n = 5, 29.4%). In ICI-induced colitis, cytotoxic T cells (Tc cells) were more predominant than helper T cells (Th cells) (p = 0.053), and this trend was most pronounced in the MC-like subtype (p = 0.020). When comparing the number of CD8+ cells infiltrating the crypts, both the UC-like and MC-like subtypes had significantly more infiltrating cells than the CD-like subtype (p = 0.008 and p = 0.016, respectively). In comparison to IBD, IBD exhibited a Th-dominant profile, whereas CD-like ICI-induced colitis had a lower Th cell density than CD (p = 0.032) and UC-like ICI-induced colitis had a higher Tc density than UC (p = 0.045).

Conclusion

Analysis of T-cell subsets of ICI-induced colitis revealed a Tc-dominant profile, contrasting with the Th dominance observed in patients with IBD. The Tc-dominant profile was evident in UC-like and MC-like subtypes, with significant crypt infiltration by CD8+ cells. Tc may play an important role in the pathophysiology of ICI-induced colitis.

Systematic review of immune checkpoint inhibitor-related gastrointestinal, hepatobiliary, and pancreatic adverse events

Gastrointestinal immune-related adverse events (GI irAEs) are common manifestations of immune checkpoint inhibitor (ICI) toxicity. We present a comprehensive systematic review of the incidence, management, and clinical course of irAEs across the entire GI system, including the luminal GI tract, liver, and pancreas. MEDLINE, Embase, Web of Science Core Collection, and Cochrane Library were used to conduct this review. All studies pertaining to GI irAEs were included. Both abstracts and full manuscripts were eligible if they included human subjects and were written in the English language. Articles not available in English, animal studies, or research not specific to GI toxicity of immunotherapy were excluded. We excluded certain article types depending on whether stronger evidence was available in the literature for a specific toxicity, for example, if prospective studies were available on a topic, retrospective studies and case reports were excluded. We extracted a final 166 articles for our review and followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for data reporting. Risk of bias tools were not used to evaluate the extracted studies given the narrative nature of this manuscript, but each study was critically appraised by the manuscript writer. We detail the incidence, presentation, evaluation, management, and outcomes of the various GI toxicities that may arise with ICI therapy. Specifically, we discuss the characteristics of upper GI toxicity (esophagitis and gastroenteritis), lower GI toxicity (colitis), hepatobiliary inflammation, pancreatitis, and rarer forms of GI toxicity. We hope this review serves as a useful and accessible clinical tool that helps physicians familiarize themselves with the nuances of gastrointestinal/hepatic/pancreatic ICI toxicity diagnosis and management.

Endoscopic findings of immune checkpoint inhibitor-related gastrointestinal adverse events

The use of immune checkpoint inhibitors (ICIs) for the treatment of various malignancies is increasing. Immune-related adverse events can occur after ICI administration, with gastrointestinal adverse events constituting a significant proportion of these events. When ICI-related diarrhea/colitis is suspected, endoscopic evaluation is recommended to differentiate it from other etiologies and assess the severity of colitis. The distribution of intestinal inflammation in ICI-related colitis demonstrates a high frequency of extensive colitis (23-86%). However, isolated right-sided colitis (3-8%) and ileitis (2-16%) are less prevalent. Endoscopic findings vary and predominantly encompass features indicative of inflammatory bowel disease, including aphthae, ulcers, diffuse or patchy erythema, mucosal edema, loss of vascular pattern, and friability. The presence of ulcers and extensive intestinal inflammation are associated with a reduced response to treatment. Microscopic inflammation can be observed even in endoscopically normal mucosa, underscoring the need for biopsies of seemingly normal mucosa. Histological findings present with acute/chronic inflammation and occasionally exhibit characteristics observed in inflammatory bowel disease, microscopic colitis, or ischemic colitis. The first-line therapeutic choice for ICI-related diarrhea/colitis with a common terminology criteria for adverse events grade of 2 or above is corticosteroids, whereas infliximab and vedolizumab are recommended for refractory cases.

Immune checkpoint inhibitor-induced diarrhea and colitis: an overview

Immune checkpoint inhibitors (ICIs) have emerged as an integral component of the management of various cancers and have contributed to significant improvements in overall survival. Most available ICIs target anti-cytotoxic T-lymphocyte-associated protein 4 (anti-CTLA4), and anti-programmed cell death 1/programmed cell death ligand 1 (anti-PD1/PDL1). Gastrointestinal immune-related adverse events remain a common complication of ICIs. The predominant manifestations include diarrhea and colitis, which often manifest concurrently as immune-mediated diarrhea and colitis (IMDC). Risk factors for developing these side effects include baseline gut microbiota, preexisting autoimmune disorders, such as inflammatory bowel disease, and type of neoplasm. The hallmark symptom of colitis is diarrhea which may be accompanied by mucus or blood in stools. Patients may also experience abdominal pain, fever, vomiting, and nausea. If not treated rapidly, ICI-induced colitis can lead to serious life-threatening complications. Current management is based on corticosteroids as first-line, and immunosuppressants like infliximab or vedolizumab for refractory cases. Microbiota transplantation and specific cytokines and lymphocyte replication inhibitors are being investigated. Optimal patient care requires maintaining a balance between treatment toxicity and efficacy, hence the aim of this review is to enhance readers' comprehension of the gastrointestinal adverse events associated with ICIs, particularly IMDC. In addition to identifying the risk factors, we discuss the incidence, clinical presentation, workup, and management options of IMDC.

Fulminant immune-related colitis after dual checkpoint inhibitor therapy: case report

Aim: Immune-related (IR) colitis is a potentially life-threatening complication of checkpoint inhibitors. Its presentation often includes diarrhea, abdominal pain and rectal bleeding and the median time to onset is 6-10 weeks post initiation of immunotherapy.Case study: We report an unusual case of fulminant IR-colitis beginning 3 days after the first dose of dual checkpoint blockade. IR-colitis was refractory to high-dose corticosteroids and was further complicated by sigmoid diverticulum perforation.Conclusion: Early-onset IR-colitis can occur, particularly in the context of combined anti-PD1 and anti-CTLA4 blockade, and clinicians should maintain a high-index of suspicion even when timing of symptom onset is atypical. Further research is needed to elucidate risk factors for early-onset IR-colitis.

Novel endoscopic scoring system for immune mediated colitis: a multicenter retrospective study of 674 patients

BACKGROUND AND AIMS

No endoscopic scoring system has been established for immune-mediated colitis (IMC). This study aimed to establish such a system for IMC and explore its utility in guiding future selective immunosuppressive therapy (SIT) use compared to clinical symptoms.

METHODS

This retrospective, international, 14-center study included 674 patients who developed IMC after immunotherapy and underwent endoscopic evaluation. Ten endoscopic features were selected by group consensus and assigned 1 point each to calculate an IMC endoscopic score (IMCES). IMCES cutoffs were chosen to maximize specificity for SIT use. This specificity was compared between IMCESs, and clinical symptoms were graded according to a standardized instrument.

RESULTS

A total of 309 (45.8%) patients received SIT. IMCES specificity for SIT use was 82.8% with a cutoff of 4. The inclusion of ulceration as a mandatory criterion resulted in higher specificity (85.0% for a cutoff of 4). In comparison, the specificity of a Mayo endoscopic subscore of 3 was 74.6%, and the specificity of clinical symptom grading was much lower at 27.4% and 12.3%, respectively. Early endoscopy was associated with timely SIT use (P < .001; r = 0.4084).

CONCLUSIONS

This is the largest multicenter study to devise an endoscopic scoring system to guide IMC management. An IMCES cutoff of 4 has a higher specificity for SIT use than clinical symptoms, supporting early endoscopic evaluation for IMC.

Gastrointestinal toxicities of proteasome inhibitor therapy

PURPOSE

Proteasome inhibitors (PIs), which cause cell death via tumor suppressor and pro-apoptotic proteins, are integral to treatment of many hematologic malignancies but are limited by their gastrointestinal adverse effects. Evidence regarding these PI-related adverse effects is scant. In this study, we evaluated gastrointestinal adverse events caused by PIs and compared gastrointestinal toxicities between bortezomib, carfilzomib, and ixazomib.

METHODS

We conducted a retrospective study of cancer patients treated with PIs at a tertiary care cancer center to investigate the clinical characteristics of PI-related gastrointestinal adverse events.

RESULTS

Our sample comprised 973 patients with PI exposure and stool studies ordered between January 2017 and December 2022. Of these, 193 patients (20%) had PI-related gastrointestinal toxicity based on clinical symptoms and stool study results. The most common symptom was diarrhea, present in 169 (88% of those with gastrointestinal toxicity). Twenty-two (11%) required hospitalization, and 71 (37%) developed recurrence of symptoms. Compared to bortezomib or carfilzomib, ixazomib had a longer interval from PI initiation to the onset of gastrointestinal symptoms (313 days vs 58 days vs 89 days, p = 0.002) and a significantly lower percentage of diarrhea-predominant presentation of gastrointestinal toxicity (71% vs 96% vs 91%, p = 0.048).

CONCLUSION

While PI-related gastrointestinal toxicities have various presentations and courses based on different regimens, the vast majority of patients presented with milder disease behavior. Despite a considerably high rate of hospitalization and recurrence after treatment necessitating optimization of clinical management, our cohort demonstrates favorable outcomes without long-term consequences.

Focus on Immune Checkpoint Inhibitors-related Intestinal Inflammation: From Pathogenesis to Therapeutical Approach

Recently, antitumor immunotherapies have witnessed a breakthrough with the emergence of immune checkpoint inhibitors (ICIs) including programmed cell death-1 (PD-1), programmed cell death-ligand 1 (PD-L1), and cytotoxic T lymphocyte antigen 4 (CTLA-4) inhibitors. Unfortunately, the use of ICIs has also led to the advent of a novel class of adverse events that differ from those of classic chemotherapeutics and are more reminiscent of autoimmune diseases, the immune-related adverse events (IRAEs). Herein, we performed an insight of the main IRAEs associated with ICIs, focusing on gastroenterological IRAEs and specifically on checkpoint inhibitor colitis, which represents the most widely reported IRAE to date. We comprehensively dissected the current evidence regarding pathogenesis, diagnosis, and management of ICIs-induced colitis, touching upon also on innovative therapies.

Studying Outcomes after Steroid-Sparing Immunosuppressive Agent vs. Steroid-Only Treatment for Immune-Related Adverse Events in Non-Small-Cell Lung Cancer (NSCLC) and Melanoma: A Retrospective Case-Control Study

BACKGROUND

The effects of steroid-sparing immunosuppressive agents (SSIAs), used for the treatment of immune-related adverse events (irAEs), on immune checkpoint inhibitor (ICI) antitumor activity is not well known. We compared tumor outcomes of patients who received corticosteroid monotherapy (CS) versus a corticosteroid plus SSIA (CS-SSIA) for irAE treatment, using statistical methods to address immortal time bias.

METHODS

We conducted a retrospective case-control study on patients ≥ 18 years with melanoma or non-small-cell lung cancer (NSCLC) treated with ≥1 ICI at a quaternary care center between 1 January 2016 and 11 January 2021. Patients were divided into two cohorts: CS or CS-SSIA. We used propensity score nearest-neighbor matching to match on tumor type, stage, and prior lines of therapy. Primary outcomes were progression-free survival (PFS) and overall survival (OS). Secondary outcomes included the time from the start of the irAE treatment to the irAE resolution. Hazard ratios (HRs) for PFS and OS were calculated using the Cox proportional hazard regression method with both (1) the time to the steroid and SSIA as time-varying covariates and (2) a binary exposure classification not accounting for the time to the treatment.

RESULTS

A total of 167 patients were included after matching (132 in the CS cohort and 35 in the CS-SSIA cohort). Sixty-six percent of all the patients had melanoma. The most common irAEs requiring treatment were gastroenterocolitis and hepatitis. In an adjusted analysis not accounting for immortal time bias, there were no significant differences in PFS (HR 0.75, 95% CI [0.46-1.23]) or OS (HR 0.82, 95% CI [0.46-1.47]). In analyses using a time-varying treatment indicator, there was a trend toward improved PFS in patients treated with SSIAs (HR 0.54, CI 0.26-1.10). There was no difference in OS (HR 1.11, CI 0.55-2.23). Patients with melanoma who specifically received infliximab had improved PFS compared to patients with CS only, after adjusting for immortal time bias (HR 0.32, CI 0.24-0.43).

CONCLUSIONS

The use of SSIAs with CS did not have worse outcomes than CS monotherapy. In melanoma, our findings showed improved PFS for the use of infliximab versus steroid monotherapy for irAEs. Large, prospective, randomized controlled trials are needed to confirm these findings and guide the optimal treatment of irAEs.

Anti-integrin αvβ6 autoantibodies are a potential biomarker for ulcerative colitis-like immune checkpoint inhibitor-induced colitis

BACKGROUND

No specific biomarker for immune checkpoint inhibitor (ICI)-induced colitis has been established. Previously, we identified anti-integrin αvβ6 autoantibodies in >90% of patients with ulcerative colitis (UC). Given that a subset of ICI-induced colitis is similar to UC, we aimed to clarify the relationship between such autoantibodies and ICI-induced colitis.

METHODS

Serum anti-integrin αvβ6 autoantibody levels were compared between 26 patients with ICI-induced colitis and 157 controls. Endoscopic images of ICI-induced colitis were centrally reviewed. Characteristics of anti-integrin αvβ6 autoantibodies in the ICI-induced colitis patients were compared with those of UC patients.

RESULTS

Anti-integrin αvβ6 autoantibodies were found in 8/26 (30.8%) patients with ICI-induced colitis and 3/157 (1.9%) controls (P < 0.001). Patients with anti-integrin αvβ6 autoantibodies had significantly more typical UC endoscopic features than those without the autoantibodies (P < 0.001). Anti-integrin αvβ6 autoantibodies in ICI-induced colitis patients were associated with grade ≥3 colitis (P = 0.001) and steroid resistance (P = 0.005). Anti-integrin αvβ6 autoantibody titers correlated with ICI-induced colitis disease activity. Anti-integrin αvβ6 autoantibodies of ICI-induced colitis exhibited similar characteristics to those of UC.

CONCLUSIONS

Anti-integrin αvβ6 autoantibodies may serve as potential biomarkers for the diagnosis, classification, risk management, and monitoring the disease activity, of ICI-induced colitis.

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.

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.

New strategies in the diagnosis and treatment of immune-checkpoint inhibitor-mediated colitis

Immune-checkpoint inhibitor-mediated colitis (IMC) is an increasingly recognized adverse event in cancer immunotherapy, particularly associated with immune checkpoint inhibitors (ICIs) such as anti-cytotoxic T-lymphocyte antigen-4 and anti-programmed cell death protein-1 antibodies. As this revolutionary immunotherapy gains prominence in cancer treatment, understanding, diagnosing, and effectively managing IMC becomes paramount. IMC represents a unique challenge due to its immune-mediated nature and potential for severe complications. However, a precise picture of IMC pathophysiology is currently unavailable. Therefore, we aimed to summarize the existing data while acknowledging the need for further research. This comprehensive review explores the mechanisms underlying ICIs, gastrointestinal adverse effects, and, in particular, IMC's incidence, prevalence, and features. Our review also emphasizes the importance of recognizing IMC's distinct clinical and histopathological features to differentiate it from other forms of colitis. Furthermore, this paper highlights the urgent need for evolving diagnostic methods, therapeutic strategies, and a multidisciplinary approach to effectively manage IMC.

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.

The JAK-STAT Pathway as a Therapeutic Strategy in Cancer Patients with Immune Checkpoint Inhibitor-Induced Colitis: A Narrative Review

Immunotherapy has emerged as a pivotal component in the treatment of various malignancies, encompassing lung, skin, gastrointestinal, and head and neck cancers. The foundation of this therapeutic approach lies in immune checkpoint inhibitors (ICI). While ICIs have demonstrated remarkable efficacy in impeding the neoplastic progression of these tumours, their use may give rise to substantial toxicity, notably in the gastrointestinal domain, where ICI colitis constitutes a significant aspect. The optimal positioning of Janus kinase (JAK)-signal transducer and activator of transcription (STAT) pathway inhibitors in the therapeutic management of ICI colitis remains unclear. Numerous reports have highlighted notable improvements in ICI colitis through the application of pan-JAK-STAT inhibitors, with tofacitinib, in particular, reporting evident clinical remission of colitis. The precise mechanism by which JAK-STAT inhibitors may impact the pathogenetic process of ICI colitis remains inadequately understood. However, there is speculation regarding their potential role in modulating memory resident CD8+ T lymphocytes. The elucidation of this mechanism requires further extensive and robust evidence, and ongoing JAK-STAT-based trials are anticipated to contribute valuable insights.

Practice Changes in Checkpoint Inhibitor-Induced Immune-Related Adverse Event Management at a Tertiary Care Center

Understanding of immune-related adverse events (irAEs) has evolved rapidly, and management guidelines are continually updated. We explored temporal changes in checkpoint inhibitor-induced irAE management at a tertiary cancer care center to identify areas for improvement. We conducted a single-center retrospective study of patients who developed a gastrointestinal, pulmonary, renal, or cardiac irAE between July and 1 October in 2019 or 2021. We collected patient demographic and clinical information up to 1 year after toxicity. Endoscopic evaluation and specialty follow-up after discharge for patients with gastrointestinal irAEs declined between the 2019 and 2021 periods. Symptom duration and steroid taper attempts also declined. For pulmonary irAEs, rates of specialty consultation, hospital admission and readmission, and mortality improved in 2021 compared with 2019. Follow-up rates after hospital discharge were consistently low (<50%) in both periods. For cardiac irAEs, consultation with a cardiologist was frequent and prompt in both periods. Outpatient treatment and earlier specialty consultation improved outcomes with gastrointestinal irAEs. Our study exploring irAE practice changes over time identified areas to improve management; specifically, timely specialty consultation was associated with better outcomes for gastrointestinal irAEs. These findings can help improve the quality of management algorithms at our institution and may inform policies in other institutions.

Prevalence of Enteric Infections in Patients on Immune Checkpoint Inhibitors and Impact on Management and Outcomes

BACKGROUND

Stool pathogen testing is recommended as part of the initial evaluation for patients with new-onset diarrhea on immune checkpoint inhibitors (ICIs), yet its significance has not been well-studied. We aimed to determine the impact of multiplex gastrointestinal (GI) pathogen PCR testing on the clinical course and use of immunosuppressive therapy in patients who develop diarrhea on ICIs.

METHODS

This retrospective cohort included individuals who underwent GI pathogen panel PCR for diarrhea on ICIs at Memorial Sloan Kettering between 7/2015 and 7/2021. The primary outcome was use of immunosuppressive therapy for suspected immunotherapy-related enterocolitis (irEC). Secondary outcomes included diarrhea severity and endoscopic and histologic disease patterns.

RESULTS

Among 521 ICI-treated patients tested for GI pathogens, 61 (11.7%) had a positive PCR. Compared to patients without detectable infections, patients with infections had more frequent grades 3-4 diarrhea (37.7% vs. 19.6%, P < .01) and colitis (39.3% vs. 14.7%, P < .01). However, patients with infections did not have higher rates of persistent or recurrent diarrhea and were less likely to receive steroids (P < .01) and second-line immunosuppressive agents (P = .03). In 105 patients with lower endoscopy, similar trends were observed and no differences in endoscopic severity or histologic patterns were noted between groups.

CONCLUSIONS

GI infections in ICI-treated patients presenting with diarrhea are linked to more severe but self-limited clinical presentations and may be optimally treated with observation and supportive care alone. Routine and timely stool pathogen testing may help avert unnecessary empiric immunosuppression for suspected irEC, which has been linked to blunted antitumor responses and numerous adverse effects.

Immunotherapy in Gastrointestinal Cancers

Immunotherapy has revolutionised cancer treatment over the past decade. Long-term durable responses can be achieved in some cancer patient populations that were previously facing terminal disease. In this chapter, we summarise current phase 3 clinical trial evidence for the use of immunotherapy in gastrointestinal cancers (oesophageal squamous cell carcinoma, oesophago-gastric adenocarcinoma, pancreatic cancer, biliary cancer, hepatocellular carcinoma, colorectal cancer, and squamous cell cancer of the anus). We discuss meaningful biomarkers used in clinical trials to select patients most likely to benefit from immunotherapy, such as mismatch-repair deficiency (MMRd)/microsatellite instability (MSI) and programmed-death-ligand-1 (PD-L1) immunohistochemistry (IHC) expression. Clinical questions are arising regarding the role of immunotherapy in the adjuvant/perioperative setting, optimal timing of surgery in patients who respond to immunotherapy, and toxicities specific to patients with gastrointestinal malignancies. We outline the current landscape and future horizon of immunotherapy in gastrointestinal cancers, such as strategies to increase effectiveness of checkpoint blockade through combinations with other checkpoint inhibitors, cytotoxic chemotherapy, targeted agents, radiotherapy, CAR-T therapy, and cancer vaccines.

Enterocolitis and other immunotherapy and targeted therapy-related gastrointestinal manifestations: A review for gastroenterologist

New oncologic treatments, particularly immunotherapy (IT), have revolutionized the treatment of advanced-stage malignant tumors. Immune checkpoint inhibitors are the main form of IT and act by increasing T cell activity and the organism's immune response against neoplastic cells. Targeted therapy is another form of IT that acts by inhibiting oncogenes or inflammation signaling and tumor angiogenesis pathways. However, these mechanisms of tumor destruction can interfere with the host's immune self-tolerance or with the mechanisms of epithelial tissue repair and predispose to immune system-mediated adverse events that can affect multiple organs, including the digestive tract. The gastrointestinal manifestations of damage caused by IT can range from low-grade mucositis to ulceration, and in some cases, necrosis and perforation. Any part of the gastrointestinal tract can be affected, but there is greater involvement of the small bowel and colon, with a pattern similar to that seen in inflammatory bowel disease. The most common clinical manifestation is chronic diarrhea. The differential diagnosis includes enteropathogenic infections, especially those caused by opportunistic microorganisms; adverse drug reactions; and other inflammatory and malabsorption disorders. Treatment is guided by damage severity. Mild cases can be treated with antidiarrheals and rehydration in the outpatient setting; moderate cases with hospitalization, systemic steroids, and temporary suspension of IT; and severe cases with immunosuppressants or biologic agents and definitive suspension of IT.

The colitis may be microscopic, but the diarrhea is not: update on the treatment of microscopic colitis and immune checkpoint inhibitor colitis

PURPOSE OF REVIEW

Microscopic colitis is an inflammatory disease of the colon that presents as watery diarrhea with minimal to normal endoscopic changes on colonoscopy. It encompasses two common subtypes, lymphocytic colitis and collagenous colitis, which are both treated similarly.Immune checkpoint inhibitor colitis is among the most common immune-related adverse events. Endoscopic and histological findings range from normal colonic mucosa to inflammatory bowel like changes. This review article provides update in treatment and management of microscopic colitis and immune checkpoint inhibitor colitis (ICPi colitis).

RECENT FINDINGS

Recent studies on microscopic colitis have focused on the successful use of immunomodulators such as biologics for treatment of budesonide refractory microscopic colitis cases. Microscopic colitis does not confer an added risk for colorectal cancer.With the increasing usage of immunotherapy agents, immune checkpoint inhibitor colitis is becoming more common. ICPi colitis can be successfully managed with steroids, with treatment stepped up to biologics for moderate to severe cases or for mild cases that do not respond to steroids. Immunotherapy agents can be carefully re-introduced in mild cases, after treatment of ICPi colitis.

SUMMARY

Biologics can be used to treat budesonide refractory microscopic colitis. ICPi colitis can be managed with steroids and biologics in moderate to severe cases.

Pathogenesis, pathological characteristics and individualized therapy for immune-related adverse effects

Immune checkpoint inhibitors (ICIs) are a class of antitumor medications that target immune checkpoints, which induce the activation of lymphocytes. These treatments effectively prolong the survival of patients with advanced tumors, especially lung cancer. However, in addition to tumor killing effects, ICIs may also cause an imbalance between immune tolerance and immunity. Over-activated lymphocytes may cause various types of damage to multiple organs throughout the body, called immune-related adverse events. In this review, we summarize the pathogenesis, pathological characteristics, biomarkers, and therapeutic agents for immune-related adverse events.

Treatment and outcomes of immune checkpoint inhibitors-associated colitis/diarrhea: A systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICIs) have improved the outcomes of cancer patients. However, ICIs often lead to colitis/diarrhea. This study aimed to assess the treatment of ICIs-associated colitis/diarrhea and outcomes.

METHODS

PubMed, EMBASE, and Cochrane Library databases were searched for eligible studies which investigated the treatment and outcomes of colitis/diarrhea developing in patients who received ICIs. The pooled incidences of any-grade colitis/diarrhea, low-grade colitis, high-grade colitis, low-grade diarrhea, and high-grade diarrhea as well as the pooled rates of response to treatment, mortality, and ICIs permanent discontinuation and restarts in patients with ICIs-associated colitis/diarrhea were estimated using a random-effects model.

RESULTS

Among the 11,492 papers initially identified, 27 studies were included. The pooled incidences of any-grade colitis/diarrhea, low-grade colitis, high-grade colitis, low-grade diarrhea, and high-grade diarrhea were 17%, 3%, 17%, 13%, and 15%, respectively. The pooled rates of overall response, response to corticosteroid therapy, and response to biological agents were 88%, 50%, and 96%, respectively. The pooled short-term mortality in patients with ICIs-associated colitis/diarrhea was 2%. The pooled incidences of ICIs permanent discontinuation and restarts were 43% and 33%, respectively.

CONCLUSION

ICIs-associated colitis/diarrhea is common, but rarely lethal. Half of them are responsive to corticosteroid therapy. There is a fairly high rate of response to biological agents in steroid-refractory colitis/diarrhea patients.

Key Determinants of Immune-Mediated Adverse Reactions to Oncology Drugs

To overcome the epidemiological severity of cancer, developing effective treatments is urgently required. In response, immune checkpoint inhibitors (ICIs) have been revealed as a promising resolution for treatment-resistant cancers across the world. Yet, they have both advantages and disadvantages, bringing therapeutic benefits while simultaneously inducing toxicity, and in particular, immune-mediated adverse drug reactions (imADRs), to the human body. These imADRs can be pathogenic and sometimes lethal, hampering health prediction and monitoring following the provision of ICI treatment. Therefore, it is necessary to collectively identify the determinant factors that contribute to these imADRs induced by ICIs. This article evaluated treatment-, tumor-, and patient-related determinants, and indicated a research gap for future investigations on the pathogenic mechanism of imADRs and translational conversion of determinants into clinical biomarkers to aid pharmacovigilance and cancer therapies.

IL12/23 Blockade for Refractory Immune-Mediated Colitis: 2-Center Experience

INTRODUCTION

Immune checkpoint inhibitor-mediated colitis (IMC) is commonly managed with steroids and biologics. We evaluated the efficacy of ustekinumab (UST) in treating IMC refractory to steroids plus infliximab and/or vedolizumab.

RESULTS

Nineteen patients were treated with UST for IMC refractory to steroids plus infliximab (57.9%) and/or vedolizumab (94.7%). Most of them had grade ≥3 diarrhea (84.2%), and colitis with ulceration was present in 42.1%. Thirteen patients (68.4%) attained clinical remission with UST, and mean fecal calprotectin levels dropped significantly after treatment (629 ± 101.5 mcg/mg to 92.0 ± 21.7 mcg/mg, P = 0.0004).

DISCUSSION

UST is a promising therapy for the treatment of refractory IMC.

Colon Adenoma After Diagnosis of Immune Checkpoint Inhibitor-mediated Colitis

Purpose: While the occurrence of colitis during immune checkpoint inhibitor (ICI) treatment is recognized as a sign of robust immune activation and correlates with better oncological outcomes, the long-term impact of ICI-mediated colitis on the colonic mucosa has not been studied. We thus aim to describe the colonoscopy and histology findings in patients at a follow-up time of ≥ 6 months post initial colitis event. Methods: This retrospective analysis included adult cancer patients diagnosed with ICI colitis at a tertiary cancer center between October 2013 and June 2020. The study group included patients diagnosed with immune mediated colitis who had also undergone a follow up colonoscopy or flex sigmoidoscopy. The control group was patients exposed to ICI without immune mediated colitis. We reported patients' colitis clinical course, treatment, outcomes, and endoscopic and histologic features at diagnosis and at follow-up time of ≥ 6 months. Results: Total 39 patients met the study criteria, with 82% being male, and 35.8% having melanoma. Most patients received a combination of CTLA-4 and PD-1/L1 inhibitors (82%). On initial endoscopic evaluation, inflammation without ulceration was reported in 76.9% of patients and active inflammation on histologic examination in 79.3% of patients. Most patients (79.4%) received corticosteroids, and 56.4% received add-on selective immunosuppressive therapy. Four patients received fecal microbiota transplantation. On follow-up, new incidence of colonic polyps was reported in 51.2% of patients, including adenomas in 33.3% among the colitis patients with median follow up duration of 12 months. The incidence of adenoma polyps 12 months after the colitis event was significantly higher compared to the control group without colitis based on the time-to-event analysis (p=0.041). Conclusion: At a median follow up of 12 months after their initial colitis diagnosis, 51.2% of the patients had new incidence of colonic polyps, including a third with adenoma, at a significantly higher incidence than the control group without colitis. Studies with larger sample sizes are needed to further define the long-term impact of colitis and its treatments on colon health and to refine recommendations for surveillance of colonic adenomas and colorectal cancer.

Implementing an immunotherapy toxicity (IOTOX) GI service improves outcomes in patients with immune-mediated diarrhea and colitis

PURPOSE

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but can lead to GI toxicity, termed immune-mediated diarrhea and colitis (IMDC). Standardization of IMDC management and early GI consultation is imperative to control symptoms and prevent delays in cancer care. Therefore, we implemented an inpatient algorithm and a focused IOTOX GI service to measure outcomes.

METHODS

Patients who received ICIs and were hospitalized with severe IMDC were grouped into a pre-interventional cohort in 2017, followed by implementation of the standardized algorithm in 2018, and then a post-interventional cohort of patients in 2019. Clinical data and patient outcomes were compared using univariate and multivariate analysis to determine the morbidity, and overall survival.

RESULTS

Our sample comprised 126 hospitalized patients with IMDC, with 59 patients in the pre-interventional 2017 cohort, and 67 patients in the post-interventional 2019 cohort. We found no significant differences in the clinical severity of IMDC symptoms between the two cohorts (p = 1.03) or median time from ICI exposure to development of IMDC (p = 0.495, respectively). After implementing the standardized algorithm, we observed higher rates of GI consultation (p < 0.001) in the post-treatment group. Patients in the post-treatment cohort showed decreased time to clinical remission (4 vs 10 days, p = 0.046), higher rate of GI follow-up after hospital discharge (p = 0.038), fewer hospital re-admissions (p = 0.002), and significantly fewer recurrences of IMDC symptoms (p = 0.002). Overall survival was significantly higher for at least 2 years in patients who followed with GI post-discharge compared to those without follow-up (p = 0.003).

CONCLUSION

Prompt GI consultation and monitoring of IMDC using a regimented approach can provide efficacious management, decrease time to clinical remission of symptoms, decrease re-admissions to the hospital, and improve overall patient outcomes.

Severe Immune-Mediated Colitis Induced by Checkpoint Inhibitors in an Adolescent With Lynch Syndrome

Lynch syndrome is a hereditary colorectal cancer caused by mutations in DNA mismatch repair genes. Immune checkpoint therapies have shown promise in treating Lynch syndrome-associated cancers but can lead to immune-related adverse events, such as colitis. In this report, we present a severe case of immune-mediated colitis (IMC) induced by checkpoint inhibitors in a young patient with Lynch syndrome. This 20-year-old male with Lynch syndrome and a history of glioblastoma underwent dual checkpoint therapy, after initial treatment with systemic steroids. Despite this, his condition worsened, resulting in complications, such as toxic megacolon and small bowel obstruction. He was subjected to various treatments, including infliximab and vedolizumab, but ultimately required total abdominal colectomy with J-pouch creation. This case highlights the challenges of managing severe IMC in patients with Lynch syndrome. The patient's suboptimal response to standard treatments and the development of complications emphasizes the need for a better understanding and alternative therapeutic options for IMC. This case also calls into question whether a subset of patients with IMC should be "treated to target," even though the current standard of care for IMC is guided by symptom response, and if so, further research is necessary to identify potential therapeutic targets. Further research is also required to understand the mechanisms of IMC and develop effective treatment strategies tailored to patients with Lynch syndrome and immune-related adverse events.

Checkpoint Inhibitor-Induced Colitis: From Pathogenesis to Management

The advent of immunotherapy, specifically of immune checkpoint inhibitors (ICIs), for the treatment of solid tumors has deeply transformed therapeutic algorithms in medical oncology. Approximately one-third of patients treated with ICIs may de velop immune-related adverse events, and the gastrointestinal tract is often affected by different grades of mucosal inflammation. Checkpoint inhibitors colitis (CIC) presents with watery or bloody diarrhea and, in the case of severe symptoms, requires ICIs discontinuation. The pathogenesis of CIC is multifactorial and still partially unknown: anti-tumor activity that collaterally effects the colonic tissue and the upregulation of specific systemic inflammatory pathways (i.e., CD8+ cytotoxic and CD4+ T lymphocytes) are mainly involved. Many questions remain regarding treatment timing and options, and biological treatment, especially with anti-TNF alpha, can be offered to these patients with the aim of rapidly resuming oncological therapies. CIC shares similar pathogenesis and aspects with inflammatory bowel disease (IBD) and the use of ICI in IBD patients is under evaluation. This review aims to summarize the pathogenetic mechanism underlying CIC and to discuss the current evidenced-based management options, including the role of biological therapy, emphasizing the relevant clinical impact on CIC and the need for prompt recognition and treatment.

Position statement on the management of the immune checkpoint inhibitor-induced colitis via multidisciplinary modified Delphi consensus

INTRODUCTION

The use of immune checkpoint inhibitors (ICIs) in cancer immunotherapy has shown increased overall survival in a wide range of cancer types with the associated risk of developing severe immune-mediated adverse events, commonly involving the gastrointestinal tract.

AIM

The aim of this position statement is to provide an updated practice advice to the gastroenterologists and oncologists on the diagnosis and management of ICI-induced gastrointestinal toxicity.

METHODOLOGY

The evidence reviewed in this paper includes a comprehensive search strategy of English language publications. Consensus was reached using a three-round modified Delphi methodology and approved by the members of the Belgian Inflammatory Bowel Disease Research and Development Group (BIRD), Belgian Society of Medical Oncology (BSMO), Belgian group of Digestive Oncology (BGDO), and Belgian Respiratory Society (BeRS).

CONCLUSIONS

The management of ICI-induced colitis requires an early multidisciplinary approach. A broad initial assessment is necessary (clinical presentation, laboratory markers, endoscopic and histologic examination) to confirm the diagnosis. Criteria for hospitalisation, management of ICIs, and initial endoscopic assessment are proposed. Even if corticosteroids are still considered the first-line therapy, biologics are recommended as an escalation therapy and as early treatment in patients with high-risk endoscopic findings.

Clinical Features and Management of Acute and Chronic Radiation-Induced Colitis and Proctopathy

BACKGROUND

RICAP is a recognized adverse effect of radiation therapy (RT) that can adversely affect cancer patients' quality of life. Data on the clinical characteristics and outcomes of RICAP are scarce. We aimed to analyze the clinical and endoscopic characteristics of acute or chronic radiation-induced colitis and proctopathy (ARICAP and CRICAP) based on symptom onset after RT (≤ or >45 days, respectively).

METHODS

This is a retrospective observational study of a single tertiary cancer center, from January 2010 and December 2018, of cancer patients with endoscopically confirmed ARICAP and CRICAP. We conducted univariate and multivariate logistic regression analyses to associate clinical variables with endoscopic and medical outcomes.

RESULTS

One hundred and twelve patients were included (84% Caucasian; 55% female; median age of 59 years); 46% had ARICAP with non-bloody diarrhea as the predominant symptom, whereas 55% had CRICAP with mostly bloody diarrhea. Neovascularization was the most frequent finding on endoscopy, followed by bleeding. ARICAP patients more often received medical management (p < 0.001), whereas CRICAP patients with bleeding more often received argon plasma coagulation (APC) (p = 0.002). Female sex and undergoing less-intense RT treatments were more associated with medical treatment; bleeding clinically and during the endoscopy was more associated with APC treatment. However, APC treatment did not significantly reduce bleeding recurrence or RICAP symptoms.

CONCLUSION

Patients with ARICAP and CRICAP experience different symptoms. Medical management should be considered before endoscopic therapy. APC may be useful in patients with endoscopically apparent bleeding.

Calprotectin in Patients with Rheumatic Immunomediated Adverse Effects Induced by Checkpoints Inhibitors

BACKGROUND

this is an exploratory study to evaluate calprotectin serum levels in patients with rheumatic immune-related adverse events (irAEs) induced by immune checkpoint inhibitor (ICI) treatment.

METHODS

this is a retrospective observational study including patients with irAEs rheumatic syndromes. We compared the calprotectin levels to those in a control group of patients with RA and with a control group of healthy individuals. Additionally, we included a control group of patients treated with ICI but without irAEs to check calprotectin levels. We also analysed the performance of calprotectin for the identification of active rheumatic disease using receiver operating characteristic curves (ROC).

RESULTS

18 patients with rheumatic irAEs were compared to a control group of 128 RA patients and another group of 29 healthy donors. The mean calprotectin level in the irAE group was 5.15 μg/mL, which was higher than the levels in both the RA group (3.19 μg/mL) and the healthy group (3.81 μg/mL) (cut-off 2 μg/mL). Additionally, 8 oncology patients without irAEs were included. In this group, calprotectin levels were similar to those of the healthy controls. In patients with active inflammation, the calprotectin levels in the irAE group were significantly higher (8.43 μg/mL) compared to the RA group (3.94 μg/mL). ROC curve analysis showed that calprotectin had a very good discriminatory capacity to identify inflammatory activity in patients with rheumatic irAEs (AUC of 0.864).

CONCLUSIONS

the results suggest that calprotectin may serve as a marker of inflammatory activity in patients with rheumatic irAEs induced by treatment with ICIs.

Checkpoint Inhibitor-Induced Colitis: An Update

Immunotherapy with immune checkpoint inhibitors (ICIs) nowadays has indications for several solid tumors. The current targets for ICIs are CTLA-4, PD-1, and PD-L1 receptors. Despite the clinical advantages derived from ICIs, a variety of side effects are linked to overstimulation of the immune system. Among these, ICI-related colitis is one of the most common, with a disabling impact on the patient. Diarrhea, abdominal pain, abdominal distension, cramping, and hematochezia are the most common ICI enterocolitis presenting symptoms. The most frequently used grading system for assessment of the severity of ICI enterocolitis is called the Common Terminology Criteria for Adverse Events (CTCAE) grading. With regard to the histological picture, there is no specific feature; however, microscopic damage can be classified into five types: (1) acute active colitis, (2) chronic active colitis, (3) microscopic colitis-like, (4) graft-versus-host disease-like, and (5) other types. Supportive therapy (oral hydration, a bland diet without lactose or caffeine, and anti-diarrheal agents) is indicated in mild colitis. Symptomatic treatment alone or with loperamide, a low-fiber diet, and spasmolytics are recommended for low-grade diarrhea. In more severe cases, corticosteroid treatment is mandatory. In refractory cases, off-label use of biological therapies (infliximab or vedolizumab) was proposed.

Immune Checkpoint Inhibitor Enterocolitis vs Idiopathic Inflammatory Bowel Disease

Immune checkpoint inhibitors have revolutionized management of advanced malignancies. However, their use is frequently complicated by immune related adverse events (irAEs), immune checkpoint inhibitor enterocolitis (IMEC) being the most common toxicity. IMEC is a distinct form of bowel inflammation that is highly reminiscent of idiopathic inflammatory bowel disorders (Crohn's disease, ulcerative colitis, and microscopic colitis). In this review, we highlight the similarities and differences in the pathophysiology, clinical presentation, evaluation, and management of these overlapping immune inflammatory bowel disorders. IMEC is an inflammatory bowel disease-like irAE that occurs as an outcome of disruption of intestinal immune surveillance and gut dysbiosis. Clinical and endoscopic presentation of both entities is strikingly similar, which often guides management. Though well established in inflammatory bowel disease, little is known about the long term outcomes of IMEC.

Immunotherapy Resumption/Rechallenge in Melanoma Patients after Toxicity: Do We Have Another Chance?

Introduction: Immune checkpoint inhibitors (ICIs) have radically changed the prognosis of several neoplasias, among them metastatic melanoma. In the past decade, some of these new drugs have appeared together with a new toxicity spectrum previously unknown to clinicians, until now. A common situation in daily practice is that a patient experiences toxicity due to this type of drug and we need to resume or rechallenge treatment after resolving the adverse event. Methods: A PubMed literature review was carried out. Results: The published data regarding the resumption or rechallenge of ICI treatment in melanoma patients is scarce and heterogeneous. Depending on the study reviewed, the recurrence incidence of grade 3–4 immune-related adverse events (irAEs) ranged from 18% to 82%. Conclusion: It is possible to resume or rechallenge, but each patient should be evaluated by a multidisciplinary team for close monitoring and assessment of the risk/benefit ratio before initiating treatment.

Immune-related adverse events in checkpoint blockade: Observations from human tissue and therapeutic considerations

Checkpoint inhibitors (CPIs) are monoclonal antibodies which, by disrupting interactions of immune checkpoint molecules with their ligands, block regulatory immune signals otherwise exploited by cancers. Despite revolutionary clinical benefits, CPI use is associated with an array of immune-related adverse events (irAEs) that mirror spontaneous autoreactivity. Severe irAEs necessitate pausing or stopping of CPI therapy and use of corticosteroids and/or other immunomodulatory interventions. Despite increasingly widespread CPI use, irAE pathobiology remains poorly understood; its elucidation may point to targeted mitigation strategies and uncover predictive biomarkers for irAE onset in patients, whilst casting new light on mechanisms of spontaneous immune-mediated disease. This review focuses on common CPI-induced irAEs of the gut, skin and synovial joints, and how these compare to immune-mediated diseases such as ulcerative colitis, vitiligo and inflammatory arthritis. We review current understanding of the immunological changes reported following CPI therapy at the level of peripheral blood and tissue. Many studies highlight dysregulation of cytokines in irAE-affected tissue, particularly IFNγ and TNF. IrAE-affected tissues are also predominantly infiltrated by T-cells, with low B-cell infiltration. Whilst there is variability between studies, patients treated with anti-programmed cell death-1 (PD-1)/PDL-1 therapies seem to exhibit CD8+ T-cell dominance, with CD4+ T-cells dominating in those treated with anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) monotherapy. Interestingly, CD8+CXCR3+ T-cells have been reported to be elevated in gastrointestinal, dermatological and musculoskeletal -irAE affected tissues. These findings may highlight potential opportunities for therapeutic development or re-deployment of existing therapies to prevent and/or improve the outcome of irAEs.

Immune-Related Adverse Events of the Gastrointestinal System

Immune checkpoint inhibitors (ICI) are a form of immunotherapy that have revolutionized the treatment of a number of cancers. Specifically, they are antibodies targeted against established and emerging immune checkpoints, such as cytotoxic T-cell antigen 4 (CTLA4), programmed cell death ligand 1 (PD-L1) and programmed cell death 1 protein (PD-1) on CD8-positive T cells, which promote the destruction of tumor cells. While the immune checkpoint inhibitors are very effective in the treatment of a number of cancers, their use is limited by serious and in some cases life-threatening immune-related adverse events. While these involve many organs, one of the most prevalent serious adverse events is immune checkpoint inhibitor colitis, occurring in a significant proportion of patients treated with this therapy. In this review, we aim to broadly describe the immune-related adverse events known to occur within the gastrointestinal system and the potential role played by the intestinal microbiome.

Characteristics and usefulness of transabdominal ultrasonography in immune-mediated colitis

BACKGROUND/AIMS

The usefulness of ultrasonography (US) in diseases of the gastrointestinal tract has been reported recently. This prospective study aimed to determine the features of US findings in immune-mediated colitis (IMC), an adverse event induced by immune checkpoint inhibitor, and examine the correlation between US findings, colonoscopy (CS) findings, and severity of colitis.

METHODS

We studied patients examined using CS and US upon suspicion of IMC in Hokkaido University Hospital between April 2018 and February 2021. Endoscopic findings of IMC were assessed using the Ulcerative Colitis Endoscopic Index of Severity (UCEIS). The severity of US findings in IMC was evaluated using US grade, which is the ultrasonographic grading scale in ulcerative colitis. Bowel wall thickness and the intensity of the color Doppler signal were also analyzed. Severity of colitis was evaluated using Common Terminology Criteria for Adverse Events (CTCAE) grade version 5.

RESULTS

Fourteen patients with IMC were enrolled. The US findings were bowel wall thickening, loss of stratification, ulceration and increased blood flow signal. The US grade was moderately correlated with the UCEIS (r=0.687, p=0.009) and CTCAE grade (r=0.628, p=0.035). Bowel wall thickness and UCEIS (r=0.628, p=0.020), as well as color Doppler signal grade and CTCAE grade (r=0.724, p=0.008), were significantly correlated.

CONCLUSIONS

US findings in IMC were mainly similar to those of ulcerative colitis, but there were some findings that were characteristic only of IMC. Significant correlation was found between US findings, CS findings, and severity of colitis. Hence, US could be useful for the evaluation of IMC.

Implementing an immunotherapy toxicity (IOTOX) GI service improves outcomes in patients with immune-mediated diarrhea and colitis

PURPOSE

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy but can lead to GI toxicity, termed immune-mediated diarrhea and colitis (IMDC). Standardization of IMDC management and early GI consultation is imperative to control symptoms and prevent delays in cancer care. Therefore, we implemented an inpatient algorithm and a focused IOTOX GI service to measure outcomes.

METHODS

Patients who received ICIs and were hospitalized with severe IMDC were grouped into a pre-interventional cohort in 2017, followed by implementation of the standardized algorithm in 2018, and then a post-interventional cohort of patients in 2019. Clinical data and patient outcomes were compared using univariate and multivariate analysis to determine the morbidity, and overall survival.

RESULTS

Our sample comprised 126 hospitalized patients with IMDC, with 59 patients in the pre-interventional 2017 cohort, and 67 patients in the post-interventional 2019 cohort. We found no significant differences in the clinical severity of IMDC symptoms between the two cohorts (p = 1.03) or median time from ICI exposure to development of IMDC (p = 0.495, respectively). After implementing the standardized algorithm, we observed higher rates of GI consultation (p < 0.001) in the post-treatment group. Patients in the post-treatment cohort showed decreased time to clinical remission (4 vs 10 days, p = 0.046), higher rate of GI follow-up after hospital discharge (p = 0.038), fewer hospital re-admissions (p = 0.002), and significantly fewer recurrences of IMDC symptoms (p = 0.002). Overall survival was significantly higher for at least 2 years in patients who followed with GI post-discharge compared to those without follow-up (p = 0.003).

CONCLUSION

Prompt GI consultation and monitoring of IMDC using a regimented approach can provide efficacious management, decrease time to clinical remission of symptoms, decrease re-admissions to the hospital, and improve overall patient outcomes.