Primary adrenal insufficiency induced by immune checkpoint inhibitors: biological, clinical, and radiological aspects

Immune checkpoint inhibitors (ICI) have become a cornerstone in medical oncology, with evolving therapeutic strategies and applications. These monoclonal antibodies, designed to enhance immune responses, have revealed a spectrum of immune -related adverse events (irAEs). While many irAEs exhibit favorable responses to corticosteroid or immunosuppressive therapy, most ICI -related endocrinopathies necessitate lifelong replacement therapy and pose significant clinical challenges. Adrenal insufficiency (AI), a noteworthy endocrine irAE, can manifest as primary AI (PAI) or secondary AI (SAI), resulting from adrenal or pituitary gland dysfunction, respectively. ICI -induced AI, albeit relatively infrequent, occurs in 1-2% of patients receiving single -agent anti -Programmed Death-1/Programmed Death-Ligand 1 (PD-1/PD-L1) or Cytotoxic T -Lymphocyte Antigen 4 (CTLA-4) therapies and in a higher range of 4-9% when ICIs are used in combinations. Recognizing and addressing ICI -induced PAI is crucial, as it often presents with acute and potentially life -threatening symptoms, especially considering the expanding use of ICI therapy. This review provides an updated overview of ICI -induced PAI, exploring its clinical, diagnostic, and radiological aspects.