Interleukin-6, a growth promoting cytokine, is present in human pituitary adenomas: an immunocytochemical study

• Published in: Clinical endocrinology (Oxford) Vol. 37; no. 2; p. 163
• Main Authors: Tsagarakis, S, Kontogeorgos, G, Giannou, P, Thalassinos, N, Woolley, J, Besser, G M, Grossman, A
• Format: Journal Article
• Language: English
• Published: England 01-08-1992
• Subjects: Adenoma - chemistry; Adenoma - metabolism; Adrenocorticotropic Hormone - metabolism; Growth Hormone - metabolism; Humans; Immunohistochemistry; Interleukin-6 - analysis; Pituitary Neoplasms - chemistry; Prolactinoma - chemistry
• ISSN: 0300-0664
• DOI: 10.1111/j.1365-2265.1992.tb02301.x

The aim of this study was to investigate the presence of interleukin-6 (IL-6) in human pituitary adenomas.
Immunocytochemistry was performed in 15 cases of pituitary adenomas obtained at transsphenoidal surgery.
Fifteen cases of pituitary adenomas were examined; these included five GH-secreting adenomas, four prolactinomas, four ACTH-secreting adenomas and two null-cell ('functionless') adenomas.
Each tumour was stained for the presence of IL-6 by means of the avidin-biotin-peroxidase complex (ABC) technique, and was also stained for GH, prolactin, ACTH and alpha-subunit by conventional immunocytochemistry.
Fourteen of the 15 tumours examined, excepting one GH-secreting tumour, demonstrated clusters of IL-6 positively stained cells; the specificity of the staining was established by a significant decrease in staining in parallel sections of all tumours studied when the anti IL-6 antibody was preabsorbed with recombinant human IL-6.
It is concluded that IL-6 immunoreactivity is present in human pituitary tumours, and is independent of the specific secretory cell product. The role of this cytokine in the pathogenesis of such tumours requires further investigation.