The sick euththyroid syndrome (SES): Focusing on the role of cytokines

In elderly patients with nonthyroidal illnesses (NTl), a reduction in T3 plasma concentrations
and an increase in reverse T3 (rT3) levels are frequently observed. This condition is
usually referred to as "low T3 syndrome", "sick euthyroid syndrome" (SES), or "nonthyroidal
illness syndrome". The pathophysiology and the clinical significance of this syndrome are
still largely unknown. ln this review of the literature, we focused on the putative role of
cytokines (such as tumor necrosis factor-o, interleukin-O, transforming growth factor-p1 and
others) as mediators of the SES. Finally, the interpretation and clinical significance of the
syndrome, and its therapeutic approach is discussed.