[Endocrinopathies Associated with Immune Checkpoint Inhibitors]

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that increase the efficiency of the immune system in the destruction of neoplastic cells. In recent years, these drugs have been increasingly used in the treatment of many neoplasms in advanced stages. However, the change in the regulation of the immune system induced by these drugs has the potential adverse effect of inducing autoimmunity in practically all organ systems. Endocrinopathies are one of the most common autoimmune adverse eventsof these drugs.

Non-systematic review of endocrinopathies reported in the context of treatment with ICIs. A search was carried out on PubMed until January 31st, 2020, and articles were selected based on their relevance and excluded in case of redundant content. The following search terms were used: "immune checkpoint inhibitor" and "endocrinopathy" / "endocrine system diseases" / "pituitary" / "thyroid" / "diabetes" / "adrenal" / "parathyroid".

Endocrinopathies with all classes of ICIs (anti-CTLA-4, anti-PD-1, anti-PD-L1) have been reported. Thyroid dysfunction is the most frequently reported endocrinopathy, mainly with anti-PD-1 and anti-PD-L1. Hypophysitis is the most prevalent with anti-CTLA-4. The incidence of autoimmune diabetes in this context is increasing, mainly with anti-PD-1 and anti-PD-L1. Rare cases of primary adrenal insufficiency, Graves' disease and primary hypoparathyroidism have also been reported.

Knowing the spectrum of endocrinopathies triggered by ICI, as well as their clinical features, diagnosis and treatment criteria is essential, given its high prevalence and the increasing number of cancer patients treated with these new drugs.