Immune System and Pituitary Tumors: TILs Death tears them Apart. A Review

Abstract

Introduction: Pituitary tumors are common in general population, but the study of these tumors confronts some restrictions, including the inaccessibility of the gland for biopsy material. It has also been described that lymphocytic infiltration can be found adjacent to pituitary adenomas. Objective: This article was conceived to collect some information to describe the involvement of immune system on pituitary tumors microenvironment and also to shed light to molecular mechanisms implicated on the pathogenesis of these diseases. Methods: A search of the literature was done in Medline database between 1990 and 2014, using the search terms immune system and pituitary tumors. A review of 88 papers was performed including articles published mainly in English-language and with free access to full paper. The most recent references were used whenever possible. Results: Cell-mediated immunity appears to be predictive of a less favorable clinical outcome. Also sera antipituitary antibodies can be obtained from patients with those tumors. Low sensitivity of individual autoantibodies makes them, at present, a poor diagnostic marker for clinical purposes. Conclusions: Nonetheless, tumors infiltrating lymphocytes (TILs) and anti-pituitary antibodies (APA) still make part of a promising calling for diagnosis and treatment of pituitary tumors; new approaches to further understanding of immune response enrollment on pituitary tumor microenvironment are still needed.