New Molecular, Biological, and Immunological Agents Inducing Hypophysitis

Hypophysitis is a relatively rare disease that exerts a strong autoimmune component encompassing different etiologies. Immunomodulatory drugs, such as interferon-α, are known to rarely induce hypophysitis. In recent years, a large number of new biological and immunomodulatory agents have been introduced into clinical practice. Although immune-suppressing agents used for the treatment of autoimmune disorders only rarely are associated with hypophysitis, it is commonly encountered with immunomodulatory agents used for the treatment of cancer. Hypophysitis related to anti-cytotoxic T-lymphocyte-associated antigen-4 antibodies (anti-CTLA-4 Abs) occurs with a prevalence ranging from 0 to 18% and is considered a distinctive side effect of anti-CTLA-4 Abs treatment. Hypophysitis due to the programmed cell death protein-1 antibodies and their ligand is less common, its frequency ranging from 0 to 0.8%. No cases of hypophysitis have been described with molecular targeted agents. Diagnosis of hypophysitis still remains clinical since anti-pituitary antibodies are not a sensitive marker and thus its true prevalence is probably underestimated. The pathophysiology of hypophysitis induced by anticancer agents is not fully clarified. In most cases, treatment requires dose adjustment of the offending drug and pituitary hormone replacement. This mini-review aims to present currently available information regarding hypophysitis related to new molecular, biological, and immunological agents.