Immune function in hypopituitarism; time to reconsider?

Abstract

Abstract Hypopituitarism is not currently considered as a potential cause of immune disruption in humans. Accumulating data from in-vitro and animal models support a role for the pituitary gland in immune regulation. Furthermore the increased mortality risk noted in patients with adult hypopituitarism remains poorly explained and immune dysfunction could conceivably contribute to this observation. In a recent issue of Clinical & Experimental Immunology we presented new data relating to immune status in adults with treated, severe hypopituitarism. We observed humoral immune deficiency in a significant proportion, despite stable pituitary replacement, including growth hormone (GH). This was especially evident in those with low pre-treatment IGF-I levels and appeared independent of anticonvulsant use or corticosteroid replacement. These observations require substantiation with future studies. In this short review we summarise existing data relating to the effects of pituitary hormones on immune function, and discuss potential clinical implications surrounding the hypothesis of immune dysregulation in severe hypopituitarism.