Immune-mediated colitis after immune checkpoint inhibitor therapy

Autoimmune-related adverse events induced by immune checkpoint inhibitors

Targeted immunotherapies, particularly immune checkpoint inhibitors (ICIs), have transformed cancer treatment by significantly improving patient response and survival rates. However, ICIs could disrupt self-tolerance, inducing the development of immune-related adverse events (irAEs). Most irAEs are classified as autoimmune conditions mediated by ICI-activated CD8+ cytotoxic T cells or activated B cells producing pathogenic autoantibodies. These irAEs phenotypically resemble spontaneous autoimmune disease and lead to considerable morbidity, health care costs, and compromised treatment efficacy. With the widespread use and new emergence of ICIs, the spectrum of ICI-induced irAEs has become increasingly extensive and complex. Concurrently, research in this field is advancing rapidly, a review summarizing the latest progress on irAEs is timely and essential. In this review, we highlight numerous recent research advances, covering the epidemiology, immune mechanisms, and diverse manifestations of irAEs, with a particular focus on organ-specific autoimmunity. We also discuss current strategies, challenges, and future directions for the prevention and therapeutic management of these adverse events.

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.

A Case Report of Metastatic Melanoma in the Transverse Colon

Colonic metastasis from melanoma is extremely rare and is often asymptomatic, complicating detection. Diagnosis requires imaging and endoscopic evaluation. Treatment typically involves surgical resection with systemic therapies like immunotherapy and targeted therapy. However, immunotherapy has increased immune-related adverse events, including gastrointestinal perforation, a rare but serious complication. This report details a case of a Caucasian male patient in his 60s with a history of excised scalp melanoma eight years prior, who developed metastatic melanoma in the transverse colon. After initiating combination immunotherapy with ipilimumab/nivolumab, he suffered a bowel perforation, necessitating palliative care. The case underscores the need for vigilant monitoring for asymptomatic gastrointestinal tract metastases in melanoma patients and careful risk assessment when considering immunotherapy. It emphasizes the challenge of balancing aggressive treatment with managing potentially severe adverse events.

Yeast paves the way for cancer immunotherapy

In this issue of Cell Chemical Biology, Rebeck et al.1 construct a system that enables Saccharomyces cerevisiae var. boulardii (Sb) to secrete immune checkpoint inhibitors, reducing intestinal tumor load. This safe and effective delivery platform using engineered yeast demonstrates potential for enhancing the efficacy of biologics.