The role of autoimmunity in pituitary dysfunction due to traumatic brain injury

Traumatic brain injury (TBI) is one of the most common causes of mortality and long-term disability and it is associated with an increased prevalence of neuroendocrine dysfunctions. Post-traumatic hypopituitarism (PTHP) results in major physical, psychological and social consequences leading to impaired quality of life. PTHP can occur at any time after traumatic event, evolving through various ways and degrees of deficit, requiring appropriate screening for early detection and treatment. Although the PTHP pathophysiology remains to be elucitated, on the basis of proposed hypotheses it seems to be the result of combined pathological processes, with a possible role played by hypothalamic-pituitary autoimmunity (HPA). This review is aimed at focusing on this possible role in the development of PTHP and its potential clinical consequences, on the basis of the data so far appeared in the literature and of some results of personal studies on this issue.

Scrutinizing the data so far appeared in literature on this topic, we have found only few studies evaluating the autoimmune pattern in affected patients, searching in particular for antipituitary and antihypothalamus autoantibodies (APA and AHA, respectively) by simple indirect immunofluorescence.

The presence of APA and/or AHA at high titers was associated with an increased risk of onset/persistence of PTHP.

HPA seems to contribute to TBI-induced pituitary damage and related PTHP. However, further prospective studies in a larger cohort of patients are needed to define etiopathogenic and diagnostic role of APA/AHA in development of post-traumatic hypothalamic/pituitary dysfunctions after a TBI.