Interleukin-6, a growth promoting cytokine, is present in human pituitary adenomas: an immunocytochemical study.
OBJECTIVE
The aim of this study was to investigate the presence of interleukin-6 (IL-6) in human pituitary adenomas.


METHODS
Immunocytochemistry was performed in 15 cases of pituitary adenomas obtained at transsphenoidal surgery.


METHODS
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.


METHODS
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.


RESULTS
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.


CONCLUSIONS
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.
Tsagarakis
S
S
Department of Endocrinology, Evangelismos Hospital, Athens, Greece.
Kontogeorgos
G
G
Giannou
P
P
Thalassinos
N
N
Woolley
J
J
Besser
G M
GM
Grossman
A
A
D000236:Adenoma / Q000737:chemistry* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D015850:Interleukin-6 / Q000032:analysis*; D010911:Pituitary Neoplasms / Q000737:chemistry*; D015175:Prolactinoma / Q000737:chemistry
D015850:Interleukin-6; D000324:Adrenocorticotropic Hormone; D013006:Growth Hormone