EXPRESSION OF CYTOKINES IN THE THYROID - THYROCYTES AS POTENTIAL CYTOKINE PRODUCERS

The unstimulated and stimulated thyrocyte is able to produce more diff erent cytokines in vitro than any other endocrine cell. Cytokines prod uced by thyrocytes may play a role in the local stimulation and mainte nance of immune responses against autoantigens in the thyroid, in the modulation of goiter size in response to TSH, and in the clinical cour se of patients with thyroid tumors. This paper tries to summarize the results of relevant studies investigating cytokine production by thyro cytes. Although there is an agreement in published work that thyrocyte s secrete a number of cytokines such Il-1, Il-6, Il-8 and TGF-beta in vitro it is unclear whether these factors are produced also by thyrocy tes in vivo. By the example of GM-CSF in vitro secretion by stimulated anaplastic thyroid carcinoma cell lines and stimulated thyrocytes, th e relevance of these findings during the clinical course of patients w ith anaplastic thyroid tumours is discussed.