Inflammatory gastrointestinal diseases associated with PD-1 blockade antibodies

Cellular interactions in self-directed immune-mediated liver diseases

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

Next-generation probiotics Alistipes onderdonkii enhances the efficacy of anti-PD-1 therapy in colorectal cancer

Despite significant breakthroughs of therapeutic antibodies targeting PD-1 in cancer treatment, most colorectal cancer (CRC) patients respond poorly to anti-PD-1 immunotherapy. The combination therapy strategies are used to overcome the limitations mentioned above. Alistipes (A.) onderdonkii has anti-cancer effects. This study aimed to examine A. onderdonkii's effects and the related mechanisms in the anti-PD-1 treatment for CRC. In this study, anti-PD-1 therapy notably affected gut microbiota community composition in mice, particularly upregulating A. onderdonkii abundance. A. onderdonkii supplementation markedly promoted anti-PD-1 therapy's effectiveness on CRC treatment, as manifested by the elevated CD8+ T cell infiltration, promoted intestinal barrier integrity, and affected serum metabolomics. A. onderdonkii showed similar effects to the identified next-generation probiotics (NGP) Akkermansia (A.) muciniphila. Additionally, the combination therapy of anti-PD-1 and probiotics supplementation reduced PD-1 level and elevated IL-2 level, indicating that anti-PD-1 combined with A. onderdonkii efficiently restored T cell functions by inhibiting suppressive checkpoints. In conclusion, anti-PD-1 plus A. onderdonkii supplementation could account for a potential method for CRC therapy. These results provide strong evidence for A. onderdonkii as a potential NGP.

An updated review on immune checkpoint inhibitor-induced colitis: epidemiology, pathogenesis, treatment strategies, and the role of traditional Chinese medicine

Immune checkpoint inhibitor-induced colitis (irColitis) is a common and severe adverse reaction to immune checkpoint inhibitors (ICIs), significantly impacting the treatment outcomes and quality of life of cancer patients. Epidemiological studies indicate that the incidence of irColitis is associated with factors such as the type of ICIs, the patient's gender, age, and medical history. Although the exact pathophysiology remains unclear, irColitis is thought to be related to immune system activation and dysregulation, gut microbiota imbalance, and impaired epithelial barrier function. This review summarized the epidemiology, clinical presentation, diagnostic criteria, and pathogenesis of irColitis. Additionally, the standard and novel therapeutic strategies of irColitis, including corticosteroids, biologics, and gut microbiota interventions, more importantly the potential and application of Traditional Chinese Medicine (TCM). Future researches call for deeper mechanistic investigations, the development of biomarkers, and reveal the integration of TCM therapies within individual immunotherapy frameworks.

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.

Anti-PD1-/PDL1-induced chronic intestinal pseudo-obstruction: three cases treated with vedolizumab after corticosteroid failure with mixed results

Immune checkpoint inhibitors (ICI), i.e., anti-PD1/PDL1 and anti-CTLA-4, have reshaped the prognosis of many cancers. Increased use of ICI has led to the onset of new adverse events. Neurological immune-related adverse events are rare, heterogenous, and potentially life-threatening. Chronic intestinal pseudo-obstruction (CIPO) is an immune-related autonomic plexus neuropathy that may be caused by infiltration of the myenteric plexus by CD8 + T cells. It is a rare and potentially fatal side effect that can be difficult to diagnose early because of initial nonspecific clinical presentation including vomiting, nausea, diarrhea, and constipation. Some rare cases have been described in the literature reporting a frequent resistance to corticosteroids making it necessary to use other immunosuppressive therapy. Vedolizumab is an antibody (Ab) blocking integrin α4-β7 used to treat inflammatory bowel disease. We report the first three cases of ICI-induced CIPO-treated with vedolizumab after corticosteroid failure, with very limited benefits (only one patient with transitory improvement). Based on our results in three cases, vedolizumab does not currently appear to be a therapeutic option. Earlier administration with a standardized dose and frequency schedule may provide better outcomes.

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.

Identification of risk factors for gastrointestinal immune-related adverse events associated with immune check point inhibitors

BACKGROUND

Gastrointestinal (GI) toxicities are among the most common and potentially severe immune-related adverse events (irAEs), and data on risk factors remain limited. This study aimed to identify risk factors for GI-irAEs in patients treated with ICIs.

RESEARCH DESIGN AND METHODS

We conducted a retrospective analysis of patients with any type of malignant tumor who received ICIs between January 2020 and January 2022. GI-irAEs were defined as the onset of diarrhea during the observation period. Univariate analysis was employed to explore associations between GI-irAEs and patient characteristics.

RESULTS

Of the 485 patients screened, 361 were eligible for analysis. GI-irAEs occurred in 29 patients (8.03%). Patients with GI cancer demonstrated shorter event-free survival (EFS) compared to those with non-GI cancer (2.33, 95% CI: 1.03-4.95; p = 0.0275). Additionally, ≥ grade 2 GI-irAEs were observed in 14 patients (3.88%). Patients with GU cancer had a significantly higher incidence of GI-irAEs (odds ratio: 3.26, 95%CI 1.21-8.71, p = 0.0497) and exhibited shorter EFS (hazard ratio: 3.07, 95%CI: 1.05-8.96; p = 0.0273) compared to those with non-GU cancer.

CONCLUSION

Our findings suggest that GI cancer may be a risk factor for developing GI-irAEs, while GU cancer may predispose patients to ≥ grade 2 GI-irAEs.

The growing potential of tofacitinib in immune checkpoint inhibitor-induced colitis: identifying remaining puzzle pieces

Immunotherapy, a primary anti-neoplastic treatment, exploits the patient’s immune system to kill neoplastic cells by modulating immune checkpoints such as cytotoxic T-lymphocyte antigen 4 and programmed cell death 1. Despite an apparent anti-neoplastic efficacy, immunotherapeutic agents are often accompanied by multiorgan toxicity, including gastrointestinal ones. This particular class of immunotherapy-related adverse events, mainly represented by diarrhea and colitis, necessitates a nuanced treatment strategy. Current treatments are primarily based on standardized severity grading systems to guide and proportion therapeutic interventions, ranging from simple behavioral modifications or conventional molecules (such as anti-diarrheal) to advanced biological treatments. Tofacitinib, a pan-Janus kinase inhibitor, emerged as a potential option for managing immune-related (IR) colitis by targeting hyperactivated T cells within the colic microenvironment. However, evidence supporting the use of tofacitinib in IR colitis is primarily derived from case reports and small case series, lacking robust randomized clinical trial data. While preliminary findings demonstrate encouraging clinical control of IR colitis with tofacitinib, further research is warranted to elucidate its efficacy, safety, optimal dosage, and treatment duration. Although there are some worries about its effects on cancer response and safety, current evidence indicates that tofacitinib could be seen as a possible treatment choice if other therapies with more robust evidence profiles have not been successful.

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.

Gastrointestinal adverse events associated with immune checkpoint inhibitors: a pharmacovigilance analysis of the EudraVigilance and VigiAccess databases

BACKGROUND

This study aimed to provide an overview of gastrointestinal (GI) adverse events associated with immune checkpoint inhibitors (ICIs) using two pharmacovigilance databases, EudraVigilance and VigiAccess.

RESEARCH DESIGN AND METHODS

Data was collected from the date of ICI's marketing authorization until 30 November 2023. Reporting odds ratio (ROR) was used as a measure of ADR reporting disproportionality for signal detection.

RESULTS

Overall, across both databases, EudraVigilance and VigiAccess, a total of 76,606 ADR reports were analyzed. In EudraVigilance, colitis (12,581) and diarrhea (12,108) were the most reported GI adverse events, with similar findings in VigiAccess. Furthermore, in both databases, the most ADR reports were associated with nivolumab and pembrolizumab. Durvalumab (ROR:3.96,95%CI:3.65-4.28), ipilimumab (ROR:1.95,95%CI:1.89-2.01), nivolumab (ROR:1.05,95%CI:1.02-1.07), and atezolizumab (ROR:1.04,95%CI:1.01-1.07) demonstrated higher risks of GI events compared to other ICIs. EudraVigilance analysis identified dysphagia, ascites, hematochezia, and gastroesophageal reflux disease as potential signals associated with ICI therapy. Majority of ADR reports (87.2%) comprised serious GI adverse events, a portion of which was associated with fatal outcomes (14.5%). Atezolizumab (14.9%) and pembrolizumab (11.9%) were linked to a higher incidence of fatal outcomes compared to other ICIs.

CONCLUSION

The differential risk profiles of ICIs-associated-GI adverse events underscore the importance of personalized therapy in oncology.

Biomarkers associated with immune-related adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) constitute a pivotal class of immunotherapeutic drugs in cancer treatment. However, their widespread clinical application has led to a notable surge in immune-related adverse events (irAEs), significantly affecting the efficacy and survival rates of patients undergoing ICI therapy. While conventional hematological and imaging tests are adept at detecting organ-specific toxicities, distinguishing adverse reactions from those induced by viruses, bacteria, or immune diseases remains a formidable challenge. Consequently, there exists an urgent imperative for reliable biomarkers capable of accurately predicting or diagnosing irAEs. Thus, a thorough review of existing studies on irAEs biomarkers is indispensable. Our review commences by providing a succinct overview of major irAEs, followed by a comprehensive summary of irAEs biomarkers across various dimensions. Furthermore, we delve into innovative methodologies such as machine learning, single-cell RNA sequencing, multiomics analysis, and gut microbiota profiling to identify novel, robust biomarkers that can facilitate precise irAEs diagnosis or prediction. Lastly, this review furnishes a concise exposition of irAEs mechanisms to augment understanding of irAEs prediction, diagnosis, and treatment strategies.

Cytomegalovirus gastritis as a rare adverse event during combined ipilimumab and nivolumab in a patient with melanoma

Immunotherapy has improved survival outcomes of patients with advanced melanoma. Lower gastrointestinal tract immune-related adverse events (irAEs) are common during treatment; however, gastritis is not frequently observed. Herein, we report a case of severe cytomegalovirus (CMV)-related gastritis in a patient treated with ipilimumab and nivolumab for metastatic melanoma. This report presents a 60-year-old woman with stage IV BRAF wild-type melanoma. After the second course of ipilimumab-nivolumab, the patient reported epigastric discomfort after meals, anorexia, and subsequent nausea, vomiting, epigastric pain, and weight loss. Disease staging with PET/CT scan showed very good partial response and diffuse gastroduodenitis. The patient underwent esophagogastroduodenoscopy, showing severe esophageal candidiasis and diffuse hemorrhagic, edematous, and ulcerative mucosa in the whole gastric wall. Biopsies of the gastric wall were obtained. Before receipt of the final pathology report, the patient was empirically started on corticosteroids based on the clinical suspicion of immune-related gastritis, without improvement of symptoms. The hematoxylin-eosin staining demonstrated active gastritis with diffuse nuclear cytopathic viral inclusions in epithelial and interstitial cells; CMV infection was confirmed with immunohistochemical staining. The patient started ganciclovir and fluconazole, with rapid improvement of symptoms. This case presents a rare instance of CMV gastritis in a patient receiving combined anti-PD1 and anti-CTLA4 , in the absence of immune-suppression to manage an irAE. In the case of suggestive symptoms of irAEs, a high index of clinical suspicion is required to rule out concomitant or isolated infective disease. Guidelines for prophylaxis and treatment of these patients are needed, to optimize treatment results.

Open-capsule budesonide for the treatment of immune-related enteritis from checkpoint inhibitors

BACKGROUND

Limited data exist for management strategies targeting immunotherapy-related enteritis (irEnteritis). Systemic corticosteroids are commonly used but often are limited by adverse events. Enteric corticosteroids such as budesonide offer an attractive alternative; however, the ileocolonic release of enteric-coated budesonide has limited utility for diffuse enteritis. Open-capsule budesonide (OCB) is a novel therapeutic approach that offers drug delivery throughout the small bowel. We report outcomes in patients treated with OCB for confirmed or suspected irEnteritis.

METHODS

This retrospective cohort included all individuals treated with OCB for irEnteritis at Memorial Sloan Kettering from July 2018 to August 2023. Primary outcomes included clinical response, clinical remission, and corticosteroid-free remission following OCB. Secondary outcomes were OCB-related adverse events and efficacy by gastrointestinal toxicity location.

RESULTS

19 patients (53% female) with irEnteritis were treated with OCB. All patients presented with diarrhea; 15 (79%) reported anorexia with median 6 kg weight loss. 17 patients (89%) underwent esophagogastroduodenoscopy with biopsies revealing enteritis in all; 8 (42%) had concomitant colitis. 15 (79%) patients were treated previously with systemic corticosteroids: 8 (53%) were corticosteroid-dependent while 7 (47%) demonstrated non-response. 18 patients (95%) achieved clinical response, 15 (79%) attained clinical remission, and 11 (58%) had corticosteroid-free remission. Response to OCB was rapid with improvement noted after a median 4 days. 14 (74%) patients restored their pre-irEnteritis weight by OCB cessation. One mild, self-resolving adverse event was reported.

CONCLUSIONS

OCB is a safe and effective therapy for irEnteritis. OCB avoids systemic immunosuppression and successfully achieves clinical response and remission even in patients previously nonresponsive to systemic corticosteroids. Future studies are needed to optimize indications and duration.

Management of immune check-point inhibitor-associated colitis in patients with advanced metastatic cancers: A review article

Immune check-point inhibitors (ICPi) are immunomodulating agents, which have revolutionized the management of advanced metastatic cancers. Being immunomodulating agents, they are predisposed to causing colitis. This descriptive review article emphasized on the management of ICPi-associated colitis in advanced metastatic cancers. We used PubMed, Google Scholar, Scopus, and Embase databases for literature review, and terminologies commonly searched were "management," "immune check-point inhibitors," "colitis," "metastatic," "cancers," "literature," and "review." We reviewed a total of 11 articles done in the last 15 years relevant to ICPi colitis and its management; all the articles showed that diarrhea and colitis are the most common adverse effects observed in patients on ICPi, but prior to establishing the diagnosis of ICPi-causing colitis, possibility of Clostridium difficle or cytomegalovirus infections should be ruled out. Once the diagnosis of ICPi colitis is established, treatment should be started depending upon the severity of colitis. In mild severity, discontinuation of ICPi can resolve the symptoms but, in most of the patients with moderate to high severity of colitis, corticosteroids are considered a cornerstone treatment. Patients unresponsive to steroid treatment should be re-evaluated for infections after which anti-TNF therapy-infliximab or vedolizumab, cyclosporine, mycophenolate mofetil-can be considered.

Follow-up biopsies in gastrointestinal immune checkpoint inhibitor toxicity may show markedly different inflammatory patterns than initial injury

Colitis is a common manifestation of immune checkpoint inhibitor (ICI) toxicity and can present with varied histologic patterns of inflammation, some of which have been shown to be associated with specific ICI drug types. Although the histologic features of ICI colitis seen at the time of diagnosis have been described, there have been few reports following these patients over time. We evaluated initial and follow-up biopsies in 30 patients with ICI colitis and found that 37% of patients developed a different pattern of injury on follow-up biopsy compared to the initial biopsy. Patients with a different inflammatory pattern were more likely to have restarted ICI therapy before their follow-up biopsy (64%) compared to those without a change in inflammatory pattern (11%; P < 0.01). The majority of these patients had changed ICI drug types (86%). Additionally, many cases changed to an inflammatory bowel disease (IBD)-like pattern (36%), raising a question of de novo IBD. However, all of our patients with an IBD-like pattern experienced sustained resolution of symptoms without steroids or other immunosuppressive medications following discontinuation of ICI therapy, consistent with a diagnosis of ICI toxicity. Our findings suggest that follow-up biopsies in patients with ICI colitis may show a different histology and that this does not necessarily warrant a change in the histologic diagnosis to another disease.

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.

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.

Gut microbiome for predicting immune checkpoint blockade-associated adverse events

BACKGROUND

The impact of the gut microbiome on the initiation and intensity of immune-related adverse events (irAEs) prompted by immune checkpoint inhibitors (ICIs) is widely acknowledged. Nevertheless, there is inconsistency in the gut microbial associations with irAEs reported across various studies.

METHODS

We performed a comprehensive analysis leveraging a dataset that included published microbiome data (n = 317) and in-house generated data from 16S rRNA and shotgun metagenome samples of irAEs (n = 115). We utilized a machine learning-based approach, specifically the Random Forest (RF) algorithm, to construct a microbiome-based classifier capable of distinguishing between non-irAEs and irAEs. Additionally, we conducted a comprehensive analysis, integrating transcriptome and metagenome profiling, to explore potential underlying mechanisms.

RESULTS

We identified specific microbial species capable of distinguishing between patients experiencing irAEs and non-irAEs. The RF classifier, developed using 14 microbial features, demonstrated robust discriminatory power between non-irAEs and irAEs (AUC = 0.88). Moreover, the predictive score from our classifier exhibited significant discriminative capability for identifying non-irAEs in two independent cohorts. Our functional analysis revealed that the altered microbiome in non-irAEs was characterized by an increased menaquinone biosynthesis, accompanied by elevated expression of rate-limiting enzymes menH and menC. Targeted metabolomics analysis further highlighted a notably higher abundance of menaquinone in the serum of patients who did not develop irAEs compared to the irAEs group.

CONCLUSIONS

Our study underscores the potential of microbial biomarkers for predicting the onset of irAEs and highlights menaquinone, a metabolite derived from the microbiome community, as a possible selective therapeutic agent for modulating the occurrence of irAEs.

Histopathologic Manifestations of Immune Checkpoint Inhibitor Therapy-Associated Gastrointestinal Tract Injury: A Practical Review

Immune checkpoint inhibitors have revolutionized the management of many advanced cancers by producing robust remissions. They mostly target two immune regulatory pathways: cytotoxic T lymphocyte antigen-4 and programmed death-1 or its ligand. However, a flip side is the immune-related adverse events (irAEs) commonly affecting the gastrointestinal (GI) tract that can cause treatment interruptions or discontinuation. This practical review discusses the clinical and histopathologic findings of irAEs encountered in the luminal GI tract, along with histopathologic differentials that can mimic varied inflammatory, infectious, or other medication-associated etiologies and the importance of clinico-pathologic correlation for an accurate diagnosis.

Serious immune-related upper gastrointestinal toxicity of immune checkpoint inhibitors: a multicenter case series

BACKGROUND

Immune checkpoint inhibitors (ICI) improve the prognosis of many cancers but cause immune-related adverse events (IrAEs). Limited data are available on upper gastrointestinal (UGI) IrAEs. We describe the clinical characteristics, prognosis, and efficacy of medical therapy in patients with UGI IrAEs.

METHODS

This is a retrospective, multicenter cohort study of patients with UGI symptoms and moderate to severe endoscopic UGI lesions, occurring after ICI. Efficacy of induction medical therapy and at the most recent follow-up was assessed.

RESULTS

Forty patients were included; of these, 34 (85%) received anti-PD(L)1, either alone (n = 24) or combined with anti CTLA-4 (n = 10). Eighteen patients (45%) had concomitant enterocolitis. All patients had severe endoscopic lesions (erosions, ulcerations, hemorrhage, or necrotic lesions). Three patients who received an inefficient initial medical treatment had a complicated course: One patient died of enterocolitis, one had a pneumomediastinum, and one developed an ulcerated stricture of the pylorus. Thirty-five patients (88%) were treated with corticosteroids; 28 patients (80%) responded, and 20 (57%) reached clinical remission. Eight patients were treated with infliximab, and six responded (75%). After a median follow-up of 11 months, 36 patients (90%) were in corticosteroid-free clinical remission for their UGI symptoms. Endoscopic lesions persisted in 68% of patients.

CONCLUSIONS

ICI cause severe UGI IrAEs, which are associated with enterocolitis in approximately half of the patients. Most patients with UGI IrAEs respond to corticosteroids or infliximab. These data support the recommendation to treat these patients without delay and in the same way as those with enterocolitis.

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.

Perianal rhabdomyosarcoma in an adult: A case report and review of the literature

Perianal/perineal rhabdomyosarcomas (PRMS) is rare, and the outcome is poor. A 29-year-old female presented with perineal rhabdomyosarcomas revealed metastases to inguinal lymph nodes on the bilateral side. Disease progression was discovered when the patient got adjuvant epirubicin, ifosfamide, and bevacizumab for 2 cycles. After 3 cycles of nivolumab, dacarbazine, cisplatin, and vinblastine therapy, a partial response was identified in the patient. The surgical resection was performed. The patient received neoadjuvant chemotherapy before surgery and was weak after surgery, so he did not receive chemoradiotherapy. The patient succumbed after 11 months postoperatively due to widespread intraabdominal metastasis.

Severe Immune-Related Enteritis after In Utero Exposure to Pembrolizumab

Immune checkpoint blockade has become standard treatment for many types of cancer. Such therapy is indicated most often in patients with advanced or metastatic disease but has been increasingly used as adjuvant therapy in those with early-stage disease. Adverse events include immune-related organ inflammation resembling autoimmune diseases. We describe a case of severe immune-related gastroenterocolitis in a 4-month-old infant who presented with intractable diarrhea and failure to thrive after in utero exposure to pembrolizumab. Known causes of the symptoms were ruled out, and the diagnosis of pembrolizumab-induced immune-related gastroenterocolitis was supported by the results of histopathological assays, immunophenotyping, and analysis of the level of antibodies against programmed cell death protein 1 (PD-1). The infant's condition was successfully treated with prednisolone and infliximab.

Immunotherapy in hematologic malignancies: achievements, challenges and future prospects

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

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.

Review of the Immune Checkpoint Inhibitors in the Context of Cancer Treatment

Checkpoint proteins are an integral part of the immune system and are used by the tumor cells to evade immune response, which helps them grow uncontrollably. By blocking these proteins, immune checkpoint inhibitors can restore the capability of the immune system to attack cancer cells and stop their growth. These findings are backed by adequate clinical trial data and presently, several FDA-approved immune checkpoint inhibitors exist in the market for treating various types of cancers, including melanoma, hepatocellular, endometrial, lung, kidney and others. Their mode of action is inhibition by targeting the checkpoint proteins CTLA-4, PD-1, PD-L1, etc. They can be used alone as well as in amalgamation with other cancer treatments, like surgery, radiation or chemotherapy. Since these drugs target only specific immune system proteins, their side effects are reduced in comparison with the traditional chemotherapy drugs, but may still cause a few affects like fatigue, skin rashes, and fever. In rare cases, these inhibitors are known to have caused more serious side effects, such as cardiotoxicity, and inflammation in the intestines or lungs. Herein, we provide an overview of these inhibitors and their role as biomarkers, immune-related adverse outcomes and clinical studies in the treatment of various cancers, as well as present some future perspectives.

An updated review of gastrointestinal toxicity induced by PD-1 inhibitors: from mechanisms to management

PD-1 inhibitors, as one of commonly used immune checkpoint inhibitors, enable T-cell activation and prevent immune escape by blocking the PD-1/PD-L1 signaling pathway. They have transformed the treatment landscape for cancer in recent years, due to the advantages of significantly prolonging patients' survival and improving their life quality. However, the ensuing unpredictable immune-related adverse effects (irAEs) plague clinicians, such as colitis and even potentially fatal events like intestinal perforation and obstruction. Therefore, understanding the clinical manifestations and grading criteria, underlying mechanisms, available diverse therapies, accessible biomarkers, and basis for risk stratification is of great importance for the management. Current evidence suggests that irAEs may be a marker of clinical benefit to immunotherapy in patients, so whether to discontinue PD-1 inhibitors after the onset of irAEs and rechallenge after remission of irAEs requires further evaluation of potential risk-reward ratios as well as more data from large-scale prospective studies to fully validate. At the end, the rare gastrointestinal toxicity events caused by PD-1 inhibitors are also sorted out. This review provides a summary of available data on the gastrointestinal toxicity profile caused by PD-1 inhibitors, with the aim of raising clinicians' awareness in daily practice, so that patients can safely benefit from therapy.

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

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

Drug-induced digestive tract injury: decoding some invisible offenders

There is an ever-growing list of pharmacological agents, several of which are attributed to cause clinically significant gastrointestinal (GI) injury. Many patients present with significant but nonspecific symptoms, that in conjunction with the absence of relevant drug history on the requisition slip can make the histopathologic diagnosis challenging. To complicate this, although some drugs have relatively characteristic histopathologic features (such as doxycycline), there exist many other drugs that exhibit wide and varying spectra of histopathologic findings (such as immune checkpoint inhibitors or olmesartan) and have histomorphologic overlap with many other commonly encountered disease entities. This review discusses the histopathologic features of some relatively recently described drugs causing GI tract injury, namely doxycycline, tacrolimus, mycophenolate, immune checkpoint inhibitors, and olmesartan. We also discuss the common mimics in histopathologic differential and some pearls that can help distinguish GI tract injury induced by the aforementioned drugs from its mimics. Awareness of the wide spectra of histopathologic changes associated with these drugs is crucial for practicing pathologists, to avoid misdiagnosis and guiding the clinician for an optimal patient management, which usually involves modifying or discontinuing the offending drug. Needless to say, once a diagnosis of drug-induced injury is suspected, clinicopathologic correlation including corroboration with the drug history is of utmost importance as is the exclusion of dual pathology in these patients.

[Cytomegalovirus reactivation in patients with immune-mediated gastritis]

INTRODUCTION

Reactivation of cytomegalovirus can complicate the evolution of patients with gastritis induced by immune checkpoint inhibitors.

METHODS

The experience in our center is described and a review of the literature is performed.

RESULTS

A case of severe gastritis induced by treatment with a programmed cell death receptor-1 (anti-PD1) inhibitor, associated with reactivation of cytomegalovirus (CMV) is described. In the systematic review, we identified 5 cases of immune-related gastritis associated with CMV reactivation. Ganciclovir treatment contributed to clinical improvement in most patients.

CONCLUSION

The early identification of a CMV infection in patients with severe or refractory immune-related gastritis will allow the initiation of targeted treatment, and may avoid increasing immunosuppressive therapy.

Cadonilimab, a tetravalent PD-1/CTLA-4 bispecific antibody with trans-binding and enhanced target binding avidity

Clinical studies have shown that combination therapy of antibodies targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4) and programmed cell death-1 (PD-1) significantly improves clinical benefit over PD-1 antibody alone. However, broad application of this combination has been limited by toxicities. Cadonilimab (AK104) is a symmetric tetravalent bispecific antibody with a crystallizable fragment (Fc)-null design. In addition to demonstrating biological activity similar to that of the combination of CTLA-4 and PD-1 antibodies, cadonilimab possess higher binding avidity in a high-density PD-1 and CTLA-4 setting than in a low-density PD-1 setting, while a mono-specific anti-PD-1 antibody does not demonstrate this differential activity. With no binding to Fc receptors, cadonilimab shows minimal antibody-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, and interleukin-6 (IL-6)/IL-8 release. These features all likely contribute to significantly lower toxicities of cadonilimab observed in the clinic. Higher binding avidity of cadonilimab in a tumor-like setting and Fc-null design may lead to better drug retention in tumors and contribute to better safety while achieving anti-tumor efficacy.

Deaths and adverse events from adjuvant therapy with immune checkpoint inhibitors in solid malignant tumors: A systematic review and network meta-analysis

Background

By prolonging overall survival and reducing disease recurrence rates, immune checkpoint inhibitors (ICIs) are an emerging adjuvant therapy option for patients with resectable malignant tumors. However, the safety profile (deaths and adverse events [AEs]) of adjuvant ICIs has not been fully described.

Methods

We searched the literature for phase III randomized clinical trials that compared PD-1, PD-L1, and CTLA-4 inhibitors in solid malignant tumors. Incidences of death, discontinuation, AEs of any cause, treatment-related adverse events (TRAEs), and immune-related adverse events (IRAEs) were extracted for the network meta-analysis. Network meta-analyses with low incidence and poor convergence are reported as incidences with 95% confidence intervals (95% CIs).

Results

Ten randomized clinical trials that included 9243 patients who received ICI adjuvant therapy were eligible. In total, 21 deaths due to TRAEs were recorded, with an overall incidence of 0.40% (95% CI: 0.26-0.61). The treatment-related mortality rates for ipilimumab (0.76%, 95% CI: 0.31-1.55) and atezolizumab (0.56%, 95% CI: 0.18-1.31) were higher than for pembrolizumab (0.24%, 95% CI: 0.10-0.56) and nivolumab (0.30%, 95% CI: 0.08-0.77). The most frequent causes of death were associated with the gastrointestinal (0.10%, 95% CI: 0.04-0.24) and pulmonary (0.08%, 95% CI: 0.03-0.21) systems. Compared with the control arm, we found that nivolumab (odds ratio [OR]: 2.73, 95% CI: 0.49-15.85) and atezolizumab (OR: 12.43, 95% CI: 2.42-78.48) caused the fewest grade ≥3 TRAEs and IRAEs. Commonly reported IRAEs of special interest were analyzed, and two agents were found to have IRAEs with incidences >10%, i.e., hepatitis for atezolizumab (14.80%, 95% CI: 12.53-17.32) and hypophysitis for ipilimumab (13.53%, 95% CI: 11.38-15.90).

Conclusions

Ipilimumab and atezolizumab were correlated with higher treatment-related death rates than pembrolizumab and nivolumab, in which the gastrointestinal and pulmonary systems were mostly involved. Regarding severe TRAEs and IRAEs, nivolumab and atezolizumab are likely to be the safest agent, respectively. This study will guide clinical practice for ICI adjuvant therapies.

Curcumin alleviates experimental colitis via a potential mechanism involving memory B cells and Bcl-6-Syk-BLNK signaling

BACKGROUND

Immune dysfunction is the crucial cause in the pathogenesis of inflammatory bowel disease (IBD), which is mainly related to lymphocytes (T or B cells, incl-uding memory B cells), mast cells, activated neutrophils, and macrophages. As the precursor of B cells, the activation of memory B cells can trigger and differentiate B cells to produce a giant variety of inducible B cells and tolerant B cells, whose dysfunction can easily lead to autoimmune diseases, including IBD.

AIM

To investigate whether or not curcumin (Cur) can alleviate experimental colitis by regulating memory B cells and Bcl-6-Syk-BLNK signaling.

METHODS

Colitis was induced in mice with a dextran sulphate sodium (DSS) solution in drinking water. Colitis mice were given Cur (100 mg/kg/d) orally for 14 con-secutive days. The colonic weight, colonic length, intestinal weight index, occult blood scores, and histological scores of mice were examined to evaluate the curative effect. The levels of memory B cells in peripheral blood of mice were measured by flow cytometry, and IL-1β, IL-6, IL-10, IL-7A, and TNF-α expression in colonic tissue homogenates were analyzed by enzyme-linked immunosorbent assay. Western blot was used to measure the expression of Bcl-6, BLNK, Syk, and other signaling pathway related proteins.

RESULTS

After Cur treatment for 14 d, the body weight, colonic weight, colonic length, colonic weight index, and colonic pathological injury of mice with colitis were ameliorated. The secretion of IL-1β, IL-6, TNF-α, and IL-7A was statistically decreased, while the IL-35 and IL-10 levels were considerably increased. Activation of memory B cell subsets in colitis mice was confirmed by a remarkable reduction in the expression of IgM, IgG, IgA, FCRL5, CD103, FasL, PD-1, CD38, and CXCR3 on the surface of CD19+ CD27+ B cells, while the number of CD19+ CD27+ IL-10+ and CD19+ CD27+ Tim-3+ B cells increased significantly. In addition, Cur significantly inhibited the protein levels of Syk, p-Syk, Bcl-6, and CIN85, and increased BLNK and p-BLNK expression in colitis mice.

CONCLUSION

Cur could effectively alleviate DSS-induced colitis in mice by regulating memory B cells and the Bcl-6-Syk-BLNK signaling pathway.

Immune checkpoint inhibitor-mediated colitis is associated with cancer overall survival

BACKGROUND

Immune checkpoint inhibitor-mediated colitis (IMC) is a common adverse event following immune checkpoint inhibitor (ICI) therapy for cancer. IMC has been associated with improved overall survival (OS) and progression-free survival (PFS), but data are limited to a single site and predominantly for melanoma patients.

AIM

To determine the association of IMC with OS and PFS and identify clinical predictors of IMC.

METHODS

We performed a retrospective case-control study including 64 ICI users who developed IMC matched according to age, sex, ICI class, and malignancy to a cohort of ICI users without IMC, from May 2011 to May 2020. Using univariate and multivariate logistic regression, we determined association of presence of IMC on OS, PFS, and clinical predictors of IMC. Kaplan-Meier curves were generated to compare OS and PFS between ICI users with and without IMC.

RESULTS

IMC was significantly associated with a higher OS (mean 24.3 mo vs 17.7 mo, P = 0.05) but not PFS (mean 13.7 mo vs 11.9 mo, P = 0.524). IMC was significantly associated with OS greater than 12 mo [Odds ratio (OR) 2.81, 95% confidence interval (CI) 1.17-6.77]. Vitamin D supplementation was significantly associated with increased risk of IMC (OR 2.48, 95%CI 1.01-6.07).

CONCLUSION

IMC was significantly associated with OS greater than 12 mo. In contrast to prior work, we found that vitamin D use may be a risk factor for IMC.

Clinical Characteristics and Outcomes of Gastritis Associated With Immune Checkpoint Inhibitors: Scoping Review

Among immune-related adverse events associated with immune checkpoint inhibitors, immune-mediated gastritis (IMG) has been rarely described in the literature and has not yet been well characterized. This scoping review aimed to characterize IMG in terms of precipitating agents, clinical presentations, and prognosis. After the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including "gastritis," "immune checkpoint inhibitor," and "immune-related adverse event" from their inception to December 28, 2021. Twenty-two articles, including 5 observational studies and 17 case reports and case series, were included. Nivolumab, pembrolizumab, and combination therapy with those and cytotoxic T-lymphocyte-associated antigen-4 inhibitor (ipilimumab) were commonly used in those with IMG. 59.8% had epigastric pain, and 50% had erosive gastritis. 87.5% had Common Terminology Criteria for Adverse Events (CTCAE) grade 3 gastritis, and 91.2% received corticosteroids. Recurrence was noted in 16.7%, and only 1 expiration was noted. 4.3% had positive helicobacter pylori and cytomegalovirus from the gastric specimen. Similar to immune-related colitis, patients with IMG may have a favorable prognosis with a better response to immune checkpoint inhibitors if treated appropriately. The diagnosis of IMG is made by exclusion, and a thorough workup is necessary to rule out concurrent helicobacter pylori and cytomegalovirus involvement. Further studies are critical for a better understanding of this complication.

Risk of irAEs in patients with autoimmune diseases treated by immune checkpoint inhibitors for stage III or IV melanoma: results from a matched case-control study

OBJECTIVE

To quantify the risk of immune-related adverse events (irAEs) in patients with pre-existing autoimmune disease (pAID) treated by immune checkpoint inhibitors (ICIs) for stage III or IV melanoma.

METHODS

Case-control study performed on a French multicentric prospective cohort of patients with melanoma, matched for irAE risk factors and oncological staging. Risk of irAE was assessed by logistic regression.

RESULTS

110 patients with pAID were included and matched with 330 controls, from March 2013 to October 2020. Over a median follow-up period of 7.2 months for cases and 6.9 months for controls, the ORs of developing all-grade and grade ≥3 irAEs among cases compared with controls were 1.91 (95% CI (1.56 to 2.27)) and 1.44 (95% CI (1.08 to 1.82)), respectively. Patients with pAID had an increased risk of multiple irAEs (OR 1.46, 95% CI (1.15 to 2.67)) and a shorter time to irAE onset. In contrast, there were no difference in irAE-related mortality nor in the rate of treatment discontinuation, and a landmark analysis revealed a better survival at 24 months among cases (p=0.02). Thirty per cent of cases experienced a pAID flare during follow-up, and baseline immunosuppression did not prevent irAE occurrence. Last, we report associations between the pAID clinical subsets and organ-specific irAEs.

CONCLUSION

In our study, patients with pAID were at greater risk of all-grade, severe and multiple irAEs, yet had a better 24-month survival than controls. Thus, patients with pAID should be eligible for ICI therapy but benefit from a close monitoring for irAE occurrence, especially during the first months of therapy.

Immune-Related Uncommon Adverse Events in Patients with Cancer Treated with Immunotherapy

Immunotherapy has dramatically changed the therapeutic landscape of oncology, and has become standard of care in multiple cancer types in front or late lines of therapy, with some longstanding responses and outstanding results. Notwithstanding, its use has brought a totally unique spectrum of adverse events, characterized by a myriad of diverse manifestations affecting nearly every organ and system of the body, including the endocrine, nervous, cardiac, respiratory and gastrointestinal systems. Uncommon adverse events, defined as those occurring in less than 1% of patients, comprise an even more heterogeneous group of diseases that are being seen more recurrently as the use of immune check-point inhibitors increases and indications spread in different tumor types and stages. Here, we comprehensively review some uncommon, but exceedingly important, immune-related adverse events, with special emphasis in the clinical approach and diagnostic workup, aiming to reunite the evidence published previously, allowing an increase in awareness and knowledge from all specialists implicated in the diagnosis, treatment, and care of cancer patients treated with immunotherapy.

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

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

Severe immune checkpoint inhibitor-associated gastritis: A case series and literature review

Background and study aims  Recent advances in cancer treatment have involved the clinical application of immune checkpoint inhibitors (ICIs) for various type of cancers. The adverse events associated with ICIs are generally referred to as immune-related adverse events (irAEs). Gastrointestinal irAEs are a major disorder, but gastritis is not frequently observed. The aims of this study were to elucidate the clinical, endoscopic, and histological characteristics of irAE gastritis. Patients and methods  Information on patients treated with ICIs were collected from a single institute over 3 years. IrAE gastritis was identified based on the clinical course and endoscopic and histopathological findings. Of the 359 patients treated with ICIs, four cases of irAE gastritis were identified in clinical records from the endoscopy unit. The endoscopic and histopathological findings were analyzed, and further immunohistochemical studies with immune subtype markers and programmed cell death ligand-1 (PD-L1) antibody were conducted. Results  Among four patients with irAE gastritis, the remarkable endoscopic characteristics were network-pattern erosion, erythematous and edematous mucosa with thick purulent discharge, and fragile mucosa. Corresponding histological features were fibrinopurulent exudate, severe inflammatory cell infiltration, and epithalaxia, respectively. The PD-L1 expression rate was ≥ 1 % in the gastric tissue of all patients with gastritis. These patients were treated with prednisolone (PSL) and their symptoms improved within a few days to 2 weeks. Conclusions  IrAE gastritis were characterized by specific endoscopic findings. The appropriate endoscopic diagnosis may lead to effective treatment with PSL.

Pharmacological Treatments Available for Immune-Checkpoint-Inhibitor-Induced Colitis

Immune checkpoint inhibitor treatment has shown revolutionary therapeutic effects in various carcinomas. However, immune-related adverse events (irAE) following this treatment can sometimes lead to treatment discontinuation. One such frequently encountered adverse event is immune-related colitis (irAE colitis). Corticosteroids (CS) are the first-line treatment for irAE colitis, but we often encounter CS-refractory or -resistant cases. The application of multiple biologics has been proposed as a therapy to be administered after CS treatment; however, the efficacy and safety of biologics for patients with irAE colitis who do not respond to CS have not been established. This review summarizes the treatment regimens available for irAE colitis, focusing on the mechanism of action of corticosteroids, infliximab, vedolizumab, and other drugs.

Neutrophil-lymphocyte ratio predicts early outcomes in patients with unresectable hepatocellular carcinoma treated with atezolizumab plus bevacizumab: a multicenter analysis

OBJECTIVE

To investigate whether neutrophil-to-lymphocyte ratio (NLR) can predict outcomes in patients with unresectable hepatocellular carcinoma (HCC) treated with atezolizumab plus bevacizumab (Atez/Bev).

METHODS

A total of 249 patients with unresectable HCC treated with Atez/Bev were included. We analyzed survival and discontinuation of this therapy in this cohort.

RESULTS

Cumulative overall survival at 2, 4, 6, and 8 months was 97.6%, 94.9%, 88.9%, and 82.8%, respectively. Cumulative overall survival differed significantly between patients with low (<3.0) versus high (≥3.0) NLR (P = 0.001). Conversely, cumulative progression-free survival did not differ between patients with low versus high NLR. The distribution of response was 1.5% for complete response, 17.1% for partial response, 60.5% for stable disease, and 21.0% for progressive disease. Responses were not different between patients with low and high NLR. Regarding adverse events, immune-related liver injury of any grade and grade of at least 3, decreased appetite of any grade, grade of at least 3 proteinuria, and other adverse events of any grade differed significantly between patients with low and high NLR. There were 56, 18, and 2 patients who discontinued Atez/Bev therapy due to progression of disease, adverse event, and other reasons, respectively. The cumulative discontinuation rate for Atez/Bev therapy due to adverse events differed significantly between patients with low versus high NLR (P = 0.022). Cox proportional hazards modeling analysis with inverse probability weighting showed that NLR of at least 3.0 was significantly associated with overall survival (hazard ratio, 3.369; 95% confidence interval, 1.024-11.080).

CONCLUSIONS

NLR can predict outcomes in patients with unresectable HCC treated with Atez/Bev.

Diagnostic impact of 18F-FDG PET/CT imaging on the detection of immune-related adverse events in patients treated with immunotherapy

INTRODUCTION

Immunotherapy is an effective treatment method for cancer cells with humoral and cellular immune mechanisms of action but triggers an inflammatory response and disrupts standard protective immune tolerance. Early detection of immune-related adverse events (irAEs) on PET/CT is crucial for patient management and subsequent therapy decisions. In this study, we aimed to evaluate the impact of ¹⁸F-FDG PET/CT on detecting of irAEs in patients receiving immunotherapy.

PATIENTS AND METHODS

Forty-six patients with advanced RCC (n: 32), malign melanoma (n: 9), lung cancer (n: 4), and laryngeal carcinoma (n: 1), who underwent ¹⁸F-FDG PET/CT imaging for response assessment after immunotherapy, were enrolled in the study. Newly detected findings associated with irAEs on posttreatment PET/CT images were compared with the pretreatment PET/CT, both qualitatively and semi-quantitatively.

RESULTS

Twenty-eight (61%) patients developed irAEs as observed on PET/CT. Enteritis/colitis was the most frequent irAE visualized on PET/CT with 13 patients (28.2%), followed by gastritis (17.3%), thyroiditis (13%), and myositis/arthritis (13%). Hepatitis (6.5%), pneumonitis (6.5%), sarcoid-like reaction (4.3%), and hypophysitis (4.3%) were observed to a lesser extent. The median time between the appearance of irAEs on PET/CT and the initiation of immunotherapy was 4.3 months. There were no significant differences in age, sex, and treatment response status of patients with and without irAEs.

CONCLUSION

¹⁸F-FDG PET/CT plays a fundamental role in cancer immunotherapy with the potential to show significant irAEs both in the diagnosis and in follow-up of irAEs. IrAEs were present on PET/CT images of more than half of the patients who received immunotherapy in our study.

Sex Differences in Immunity

Strong epidemiological evidence now exists that sex is an important biologic variable in immunity. Recent studies, for example, have revealed that sex differences are associated with the severity of symptoms and mortality due to coronavirus disease 2019 (COVID-19). Despite this evidence, much remains to be learned about the mechanisms underlying associations between sex differences and immune-mediated conditions. A growing body of experimental data has made significant inroads into understanding sex-influenced immune responses. As physicians seek to provide more targeted patient care, it is critical to understand how sex-defining factors (e.g., chromosomes, gonadal hormones) alter immune responses in health and disease. In this review, we highlight recent insights into sex differences in autoimmunity; virus infection, specifically severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection; and cancer immunotherapy. A deeper understanding of underlying mechanisms will allow the development of a sex-based approach to disease screening and treatment.

Pharmacological Interventions for the Prevention and Treatment of Immune Checkpoint Inhibitor-Associated Enterocolitis: A Systematic Review

BACKGROUND

Patients treated with immune checkpoint inhibitors (ICIs) may develop ICI-associated enterocolitis, for which there is no approved treatment.

AIMS

We aimed to systematically review the efficacy and safety of medical interventions for the prevention and treatment of ICI-associated enterocolitis.

METHODS

MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomized controlled trials (RCTs), cohort and case-control studies, and case series/reports, evaluating interventions (including corticosteroids, biologics, aminosalicylates, immunosuppressants, and fecal transplantation) for ICI-associated enterocolitis. Clinical, endoscopic, and histologic efficacy endpoints were evaluated. The Grading of Recommendations, Assessment, Development, and Evaluation criteria were used to assess overall quality of evidence.

RESULTS

A total of 160 studies (n = 1514) were included (one RCT, 3 retrospective cohort studies, 156 case reports/case series). Very low quality evidence from one RCT suggests budesonide is not effective for prevention of ICI-associated enterocolitis in ipilimumab-treated patients (relative risk 0.93 [95% confidence interval 0.56, 1.56]). Very low quality evidence suggests that corticosteroids, infliximab, and vedolizumab may be effective for treatment of ICI-associated enterocolitis by inducing clinical response and remission. No validated indices for measuring disease activity were used. Biologic treatment was used in 42% (641/1528) of patients, as reported in 97 studies. ICIs were discontinued in 65% (457/702) of patients, as reported in 63 studies.

CONCLUSIONS

Current treatment recommendations for ICI-associated enterocolitis are based on very low quality evidence, primarily from case reports and case series. Large-scale prospective cohort studies and RCTs are needed to develop prophylactic and therapeutic treatments to minimize interruption or discontinuation of oncological therapies.