Effects of acute and chronic interleukin-6 administration on thyroid hormone metabolism in humans

J Clin Endocrinol Metab. 1994 Nov;79(5):1342-6. doi: 10.1210/jcem.79.5.7962327.


Cytokines, such as tumor necrosis factor-alpha and interleukin-1 beta (IL-1 beta), alter thyroid hormone metabolism, and may be involved in the pathogenesis of the euthyroid sick syndrome. Both cytokines also induce the production of IL-6. To assess whether IL-6 itself modulates thyroid hormone metabolism, we studied the acute and chronic effects of recombinant human IL-6 (rhIL-6) on thyroid hormone concentrations in patients with renal cell cancer. In the first study protocol, plasma thyroid hormone concentrations were measured during a 4-h infusion of rhIL-6 (150 micrograms) or, on another day, during infusion of saline (control; n = 8). There were no effects of rhIL-6 infusion on T4, free T4, or thyroid hormone-binding index. However, rhIL-6 induced a significant decrease in the plasma concentrations of TSH (P < 0.001) and T3 (P < 0.001) compared with those in the control study, associated with an increase in rT3 concentrations (P < 0.001). In the second study, a dose of 150 micrograms rhIL-6 was administered sc for 42 consecutive days (n = 8). Weekly assessment of thyroid hormone and TSH concentrations showed a decrease in the T3 concentration (P < 0.001) and a transient increase in rT3 (P < 0.01) and free T4 concentrations (P < 0.01). There were no changes in T4 concentrations during chronic administration of rhIL-6. It is concluded that IL-6 induces major changes in thyroid hormone metabolism and may be another pathogenetic factor in the euthyroid sick syndrome.

Publication types

  • Clinical Trial
  • Clinical Trial, Phase II
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Renal Cell / blood
  • Carcinoma, Renal Cell / drug therapy
  • Carcinoma, Renal Cell / metabolism
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Interleukin-6 / administration & dosage*
  • Interleukin-6 / blood
  • Interleukin-6 / therapeutic use
  • Kidney Neoplasms / blood
  • Kidney Neoplasms / drug therapy
  • Kidney Neoplasms / metabolism
  • Male
  • Middle Aged
  • Recombinant Proteins / administration & dosage
  • Recombinant Proteins / blood
  • Recombinant Proteins / therapeutic use
  • Thyroid Gland / metabolism*
  • Thyrotropin / blood
  • Thyrotropin / metabolism
  • Thyroxine / blood
  • Thyroxine / metabolism
  • Triiodothyronine / blood
  • Triiodothyronine / metabolism


  • Interleukin-6
  • Recombinant Proteins
  • Triiodothyronine
  • Thyrotropin
  • Thyroxine