Endocrine Abstracts

Introduction: Cytokines have been suggested to be involved in modulating anti-tumor responses and promoting tumor growth. Some studies have indicated that cytokines could also be involved in the pathogenesis of pituitary tumors. Th17 cells, characterized by expression of several cytokines as interleukin 22 (IL 22), might have a role in tumor immune-surveillance. IL-22 is a cytokine involved in the modulation of tissue responses during inflammation and, through activation of Stat3-signaling cascades, in the proliferative and anti-apoptotic pathways. Moreover, IL 22 expression requires the ligand-dependent transcription factor aryl hydrocarbon receptor. The aim of our study was to evaluate serum IL 22 levels in patients with tumors involving hypothalamic-pituitary region.

Design: Serum IL 22 levels were measured by a quantitative enzyme immunoassay technique in 38 consecutive patients (27 with secreting or non functioning pituitary macroadenomas; six with craniopharyngiomas; five with meningiomas or disgerminomas; 26 M, mean age 50.3±17.7 years) and in 37 healthy subjects (C: 23 M, mean age 44.9±11.72 years). Other diseases, causing increased IL 22 levels, were excluded in all cases.

Results: Serum Il 22 levels were significantly higher in patients overall than in C (28.6±13.8 vs 7.2±5.7 pg/ml, P<0.001). No differences were observed between patients with pituitary macroadenomas and those with other brain tumors. No correlation was found between serum IL 22 levels and age, gender and positive family history of autoimmune disease. Multivariate analysis did not demonstrate significant association of increased IL 22 levels with hormone hypersecretion (in pituitary adenomas), hypopituitarism or concomitant hormone replacement.

Conclusion: Patients with pituitary tumors show increased serum IL 22 levels, suggesting its hypothetical role in tumor proliferation. Nevertheless, further studies need to elucidate the involvement of this intriguing cytokine in pituitary tumorigenesis.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.