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.

Diffuse Metastatic Melanoma in the GI Lumen Following Immune Checkpoint Inhibitor Colitis Treatment

We describe the unique case of a 73-year-old man who developed diffuse metastatic melanoma throughout the GI tract following potent immunosuppressive treatment for his immune-mediated colitis. Diagnosis of his metastatic GI luminal disease was confirmed with colonoscopy and EGD biopsies. Immunosuppressive therapy including corticosteroids and vedolizumab is the mainstay treatment for immune-mediated colitis and has generally been thought to have a safe toxicity profile. This unique case of diffuse luminal metastasis of melanoma after intensive immunosuppressant treatment raised the concern of their long-term safety on the cancer outcome and the need for safer alternatives.

Ulcerative colitis exacerbation after the onset of immune checkpoint inhibitor related colitis

Immune checkpoint inhibitors (ICPI) have been reported to be effective in various carcinomas. They excessively activate the immune system, resulting in frequent immune-related adverse events (irAEs). Colitis induced by ICPI is one of the most common and is known as immune-mediated colitis (IMC). Although IMC and inflammatory bowel disease (IBD) are similar in many respects, there are very few reports of IMC in patients with preexisting IBD such as ulcerative colitis (UC) and Crohn's disease (CD). Whether preexisting IBD is concerned with the development of the colitis is not well known. Here, we reported the case who developed severe ulcerative colitis which started from IMC. It is an important case to follow the time course of the colitis developed. Our conclusion indicated that frequent colonoscopy was important for the management of IMC in a patient who has suffered chronic inflammatory disease, such as UC.

Immune-Mediated Colitis

PURPOSE OF REVIEW

This review addresses our current knowledge of immune-mediated colitis (IMC) and offers a practical guide to its management.

RECENT FINDINGS

Due to the similarity in clinical, endoscopic, and histologic findings between IMC and inflammatory bowel disease (IBD), gastroenterologists have tailored their approach to IMC management to that of IBD. Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that augment the T-cell anti-tumor response of the immune system and have demonstrated their importance in the treatment of a wide range of malignancies. With the growing benefits of ICIs, there are immune-related adverse events (irAEs) that mirror many known autoimmune diseases. Diarrhea and IMC are the most common and severe irAEs noted. No standardized guidelines exist in the management of these irAEs.

Nivolumab-induced immune-mediated colitis: an ulcerative colitis look-alike-report of new cases and review of the literature

PURPOSE

Nivolumab, a monoclonal antibody-targeting programmed cell death protein-1, is being increasingly used for the treatment of some advanced neoplasms. Several of its adverse effects are a result of the upregulation of T cells, with colitis as one of the most severe, and a challenging differential diagnosis with ulcerative colitis. However, few real-life clinical practice cases have been reported beyond trials. Our aim was to report a series of new cases, reviewing previously communicated endoscopic-proven nivolumab-induced colitis.

METHOD

All patients treated with nivolumab in three university centers were identified and those who developed immune-mediated colitis (defined as the presence of diarrhea and evidence of colitis demonstrated by colonoscopy) were described. Additionally, a review of case reports of nivolumab-induced colitis reported in the literature up to March 2018 was performed.

RESULTS

Six new cases of nivolumab-induced colitis and 13 previously reported cases out of randomized clinical trials are described. Colonoscopy showed a mucosal pattern mimicking ulcerative colitis in a large proportion of patients. Clostridium difficile superinfection was observed in two out of 19 cases. All but three patients definitively discontinued nivolumab therapy. Most patients were initially managed with oral or intravenous corticosteroids, but five of them required rescue therapy with infliximab.

CONCLUSIONS

Nivolumab-induced colitis may mimic ulcerative colitis. Steroid therapy (oral or intravenously) is often efficient, but one-fourth of patients need rescue therapy with anti-TNF. Intestinal superinfection with Clostridium difficile or cytomegalovirus should be ruled out before starting immunosuppressive therapy.

Immune checkpoint inhibitor-induced colitis: A comprehensive review

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that target down-regulators of the anti-cancer immune response: Cytotoxic T-lymphocyte antigen-4, programmed cell death protein-1, and its ligand programmed death-ligand 1. ICIs have revolutionized the treatment of a variety of malignancies. However, many immune-related adverse events have also been described which mainly occurs as the immune system becomes less suppressed, affecting various organs including the gastrointestinal tract and causing diarrhea and colitis. The incidence of immune-mediated colitis (IMC) ranges from 1%-25% depending on the type of ICI and if used in combination. Endoscopically and histologically there is a significant overlap between IMC and inflammatory bowel disease, however more neutrophilic inflammation without chronic inflammation is usually present in IMC. Corticosteroids are recommended for grade 2 or more severe colitis while holding the immunotherapy. About one third to two thirds of patients are steroid refractory and benefit from infliximab. Recently vedolizumab has been found to be efficacious in steroid and infliximab refractory cases. While in grade 4 colitis, the immunotherapy is permanently discontinued, the decision is controversial in grade 3 colitis.

Pembrolizumab-Induced Immune-Mediated Colitis in a Patient with Concurrent Clostridium Difficile Infection

Pembrolizumab is a programmed death receptor-1 (PD-1) inhibitor that has been approved for treatment of a wide variety of malignancies. Immune-mediated colitis is a known but uncommon adverse effect of pembrolizumab. Symptoms of immune-mediated colitis can be similar to those of many other gastrointestinal illnesses, including Clostridium difficile infection (CDI). If not recognized and treated in a timely fashion, immune-mediated colitis can lead to significant morbidity in cancer patients. We report the case of a 56-year-old woman on pembrolizumab for metastatic non-small cell lung cancer (NSCLC) who presented with severe colitis symptoms and initially tested positive for CDI. Her colitis symptoms worsened despite appropriate treatment for CDI but later improved rapidly after systemic corticosteroid was started for suspected immune-mediated colitis. To our knowledge, this is the first reported case of concurrent pembrolizumab-induced colitis and CDI. Immune-mediated colitis should be considered in the differential diagnoses in patients on pembrolizumab or other immune checkpoint inhibitors who present with colitis symptoms, even when a concurrent infectious etiology is suspected.