Immune checkpoint inhibitor induced colitis and arthritis: A case report.

RATIONALE: As a programmed cell death 1 (PD-1) inhibitor, camrelizumab is used in the treatment of a variety of malignancies. However, a variety of immune-mediated adverse reactions have been reported in a wide range of clinical applications, including immune-related colitis, arthritis, hepatitis, etc.

PATIENT CONCERNS: This 56-year-old male patient experienced diarrhea, bloody stool, and knee pain after receiving camrelizumab for metastatic esophageal squamous cell carcinoma. Colonoscopy showed granular changes in the whole colonic mucosa and blurred or even disappeared vascular texture. Pathology showed chronic inflammation of the colonic mucosa. Magnetic resonance imaging of knee joint showed exudative inflammatory changes in bilateral knee joints.

DIAGNOSIS: Immune checkpoint inhibitor-induced colitis and arthritis.

INTERVENTIONS: Mesalazine oral (extended-release granules, 1000 mg/quarter in die daily). Dexamethasone sodium phosphate (once daily, 5mg in the evening) and compound cypress liquid (once daily, 100ml in the evening) were given by enema. Anti-inflammatory and analgesic treatment of bone pain plaster.

OUTCOMES: The patient had diarrhea reduced to 3 times/day, no more bloody stools, and the knee pain was relieved.

LESSONS: This article describes the cases of immune-related colitis and arthritis caused by camrelizumab, and recommends considering the risk of colitis and arthritis with camrelizumab monotherapy or combination therapy.