Immune Checkpoint Inhibitor-Induced Colitis Presenting As Lymphocytic Colitis

Area of Science:

• Oncology
• Immunology
• Gastroenterology

Background:

• Checkpoint inhibitors (CPIs) represent a significant advancement in cancer therapy, enhancing survival rates in advanced malignancies.
• CPIs modulate the immune system, targeting pathways like CTLA-4, PD-1, and PD-L1, with examples including ipilimumab, pembrolizumab, nivolumab, avelumab, and atezolizumab.

Observation:

• A 45-year-old woman with BRAF-positive metastatic melanoma (V600 mutation) received nivolumab and denosumab.
• The patient developed chronic watery diarrhea, a gastrointestinal symptom.
• Colon and terminal ileum biopsies showed lymphocytic colitis-like changes.

Findings:

• The clinical presentation and biopsy results, in the context of nivolumab treatment, led to a diagnosis of checkpoint inhibitor-induced colitis.
• This case illustrates a specific adverse event associated with programmed cell death protein 1 (PD-1) inhibitor therapy.

Implications:

• Recognizing CPI-induced colitis is crucial for timely management and to prevent severe complications.
• This case underscores the importance of considering immune-related adverse events in patients receiving immunotherapy.
• Further research into the mechanisms and management of CPI-induced gastrointestinal toxicities is warranted.