Interleukin 18 (IL-18), also known as INFγ-inducing factor, is a cytokine that plays key roles in many physiological functions including immunology and metabolic processing. It serves as a biomarker or therapeutic target for a wide array of disease indications. This protein has been observed to be produced by dendritic cells, monocytes, macrophages, neutrophils, and epithelial cells. 

IL-18 exists in two forms- pro IL-18 and mature IL-18.  It is first present in the pro-form 24 kd precursor and lacks the signal sequence required for secretion1.  ICE (IL-1β Converting Enzyme) or Caspase 1 cleaves Pro-IL-18 after Asp35 activating IL-18. 2 This 18 kD active form is seen in body tissues and carries out IL-18 function, playing a crucial role in the immune defenses.


Biological significance

IL-18 has been shown to have a rapid secretion/activation response.  Induction is observed as early as 1 hour after stimulation with anti-CD40.  Further, IL-18 is indicated in various disease conditions.  High levels of IL-18 are detected in the blood of patients with allergic diseases (bronchial asthma, atopic dermatitis, allergic rhinitis, etc.) and also those with autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus (SLE), Adult Still’s disease, multiple sclerosis, Crohn’s disease, ulcerative colitis, etc.). Additionally it is found in the urine of patients with acute renal disorder3 and appears to mediate the progression of type 2 diabetes4.  The regulation and release of IL-18 is still under investigation. This could unlock the therapeutic potential of IL-18 as a biomarker or a drug target.

 MBL International is the first supplier of antibodies and ELISA kits for IL-18, these reagents are the gold standard in the IL-18 research domain. See how MBL International can help your research in IL-18. Bulk pricing is available.

IL-18 ELISA Kits

 7620 Human IL-18 ELISA Kit
 7625 Mouse IL-18 ELISA Kit

Popular IL-18 Antibody Clones

125-2H D044-3, D044-3M2
159-12BD045-3, D045-6
93-10CD048-3, D048-6

IL-18 Recombinant Proteins

Product CodeProduct Name
B001-5Recombinant human IL-18
B002-5Recombinant mouse IL-18
B003-2Recombinant Human IL-18 (-BSA)
B003-5Recombinant Human Il-18 (-BSA)
B004-2Recombinant Mouse IL-18 (-BSA)
B004-5Recombinant Mouse IL-18 (-BSA)

Data using MBL International Products

7620-Human IL 18 ELISA Kit 

D044-3 Anti-IL-18 (Human) mAb


D046-3 Anti-IL-18 (Mouse) mAb



  1. Okamura, et al. (1995). Cloning of a new cytokine that induces IFN-gamma production by T cells. Nature, 378. 88-91.
  2. Gracie, J., Robertson, S., & McInnes, I. (2003). Interleukin-18. Journal of Leukocyte Biology, 73(2), 213-224. 
  3. Washburn, K., Zappitelli, M., Arikan, A., Loftis, L., Yalavarthy, R., Parikh, C., … Goldstein, S. (2007). Urinary interleukin-18 is an acute kidney injury biomarker in critically ill children. Nephrology Dialysis Transplantation, 23(2), 566-572
  4. Trøseid, M., Seljeflot, I., & Arnesen, H. (2010). The role of interleukin-18 in the metabolic syndrome. Cardiovascular Diabetology, 9(11).
  5. Alsaleh, G., et al., J. Immunol. 182, 5088-5097 (2009)
  6. Thompson, S. R., et al., Clin. Chemist. 53, 2078-2085 (2007)
  7. Omoto, Y., et al., J. Immunol. 177, 8315-8319 (2006)
  8. Vujisic, S., et al., Hum. Reprod. 21, 2650-2655 (2006)
  9. Parikh, C. R., et al., J. Am. Soc. Nephrol. 16, 3046-3052 (2005)
  10. Tada, H., et al., Infect. Immunol. 73, 7967-7976 (2005)
  11. Baratin, M. L., et al., PNAS. 102, 14747-14752 (2005)
  12. Oku, H., et al., Hum. Reprod. 19, 709-714 (2004)
  13. Kaizu, M., et al., Virology 313, 8-12 (2003)
  14. Ahmad, R., et al., J. Virol. 76, 12448-12456 (2002)
  15. Rouabhia, M., et al., Infect. Immunol. 75, 3739-3746 (2002)
  16. Shida, K., et al., J. Immunol. 166, 6671-6679 (2001)
  17. Narita, M., et al., Clin. Diagn. Lab. 7, 909-914 (2000)
  18. Tao, D., et al., Cell Immunol. 173, 230-235 (1998)
  19. Taniguchi, M., et al., J. Immunol. Methods 206, 107-113 (1997)
  20. Micallef, M., et al., Eur. J. Immunol. 26, 1647-1651 (1996)
  21. Ushio, S., et al., J. Immunol. 156, 4274-4279 (1996)