Medicine & USMLE


  1. TNF-alpha
  2. IL-1
  3. IL-2
  4. IL-3
  5. IL-4
  6. IL-5
  7. IL-6
  8. IL-8
  9. IL-10
  10. IL-12
  11. TGF-beta
  12. IFN-alpha and IFN-beta
  13. IFN-gamma


Interleukin-6 (IL-6) is a cytokine primarily produced by macrophages. IL-6 plays a major role in acute inflammation. IL-6 also acts indirectly on the hypothalamus to cause fever. The inflammatory effects of IL-6 are involved in the pathogenesis of Giant Cell Arteritis.

Key Points

  • Interleukin-6 (IL-6)
    • Secreted by Macrophages
    • Actions
      • Causes fever
        • Via production of PGE2, which acts on hypothalamic nuclei
      • Promotes inflammation
        • Promotes vasodilation and increased capillary permeability
        • Activates endothelium to enhance leukocyte attachment and migration
      • Involved in pathogenesis of Giant Cell Arteritis (GCA)
        • Tociilizumab is a monoclonal antibody against IL-6 effective in treating GCA