Interleukin 18 (IL-18) is a cytokine that has been found to be involved in many different biological processes. So what is a cytokine?  A cytokine is protein that is secreted by certain cells and interacts/communicates between cells. And which cells produce IL-18?  IL-18 is produced by dendritic cells, monocytes, macrophages, neutrophils and epithelial cells.  IL-18 is unique in that it has two forms, mature IL-18 and pro IL-18.  IL-18 is first present as proform 24kd precursor and lacks the signal sequence required for secretion1.  However, it is the active form of IL-18 that is present in many different tissue types2.  IL-18 is cleaved so it can be in its active form.  ICE (IL-1β Converting Enzyme) or Caspase 1 cleaves Pro-IL-18 after Asp35, leading to the active form of IL-18, measuring at 18 kDa2.  This activation has shown to be an important aspect of immune defense. 


IL18 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.  IL-18 has a role in various diseases.  High levels of IL-18 are detected in the blood of patient with allergic diseases (bronchial asthma, atopic dermatitis, allergic rhinitis, etc.) and those with autoimmune diseases (rheumatoid arthritis, systemic lupus erythematosus (SLE), Adult Still’s disease, multiple sclerosis, Crohn’s disease, ulcerative colitis, etc.). IL-18 is also 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.  Results can lead to therapeutic remedies since it appears that IL-18 has significant involvement in early immune response. MBL International is the first supplier of antibodies and ELISA kits for IL-18, these reagents have become the gold standard in the IL-18 research area. See how MBL International can help your research in IL-18. Bulk pricing 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, D048-3M2

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)