Immune checkpoint inhibitor therapy-induced autoimmune polyendocrine syndrome type II and Crohn's disease: A case...

The development of immune checkpoint inhibitors (ICIs) has heralded a new era in cancer treatment, enabling the possibility of long-term survival in patients with metastatic disease. Unfortunately, ICIs are increasingly implicated in the development of autoimmune diseases.

We present a man with squamous cell carcinoma of the oropharynx on a combination of teriprizumab, docetaxel, and cisplatin therapy who developed autoimmune polyendocrine syndrome type II (APS-2) including thyroiditis and type 1 diabetes mellitus and Crohn's disease (CD). He developed thirst, abdominal pain, and fatigue after two-week treatment with the protein 1 ligand inhibitor teriprizumab. Biochemistry confirmed APS-2 and thyrotoxicosis. He was commenced on an insulin infusion. However, his abdominal pain persisted. Follow-up surgery confirmed CD and his abdominal pain was relieved by mesalazine. He was continued on insulin and mesalazine therapy.

Immunotherapy can affect all kinds of organs. When clinical symptoms cannot be explained by a single disease, clinicians should consider the possibility of multisystem damage.