Immune Checkpoint Inhibitor-Induced Adrenalitis and Primary Adrenal Insufficiency: Systematic Review and Optimal Management

Objective: Immune checkpoint inhibitors (ICIs) targeting cytotoxic T-lymphocyte antigen 4 or programmed death 1 and its ligand (programmed death ligand 1) have been approved for the treatment of a variety of cancers. However, ICI therapy is associated with a risk of immune-related adverse events. In this study, we reviewed reported cases of adrenalitis and primary adrenal insufficiency (PAI)-rare but lethal endocrine immune-related adverse events-in patients who underwent ICI therapy.

Methods: We searched multiple databases (PubMed, Web of Science, Cochrane, and Scopus) up to February 2020 for case reports on adrenalitis and PAI caused by ICIs.

Results: We identified 15 case reports on ICI-induced adrenalitis and PAI and reviewed their clinical presentation, characteristics, immunologic and imaging features, and treatment. We also developed a screening strategy for PAI in patients treated with ICIs.

Conclusion: Given the morbidity and mortality associated with acute adrenal crisis, physicians-especially endocrinologists and oncologists-should be aware of this particular risk. PAI caused by autoimmune adrenalitis predominantly occurs in patients treated with programmed death 1 inhibitor monotherapy. PAI often coexists with other endocrinopathies and requires mineralocorticoid as well as glucocorticoid replacement. Even after withdrawal of ICIs, PAI can persist and requires lifelong replacement therapy.