Interleukin-21 (IL-21) is a regulatory cytokine thought to play a role in the transition between innate and adaptive immunity. It is produced and secreted by a variety of CD4+ T cells, NK cells, and T follicular helper cells. IL-21 is a regulator in the production and proliferation of B cells, T cells, and NK cells. IL-21 activity is mediated by binding its receptor, IL-21R. Elevated levels of T follicular helper cells in rheumatoid arthritis positively correlate with increased IL-21 mRNA expression and IL-21 concentrations in patient plasma. The same phenomenon is observed in collagen-induced arthritis. It has been speculated that the mechanism is indirect regulation of RANKL by IL-21 which promotes production of osteoclasts that causes joint inflammation. In addition, IL-21 is significantly elevated in colitis-associated colon cancer, ulcerative colitis, and Crohn’s disease, along with all inflammatory bowel diseases. This creates a localized environment of inflammatory NK cells and other lymphocytes leading to further pathogenesis of the diseases. IL-21 is a target of novel therapeutic approaches such as the use of IL-21 blockers to prevent inflammation and/or malignancy.


IL-21 Singleplex Products

Our IL-21 immunoassays provide fast, accurate, reproducible, and highly sensitive measurements of IL-21. MSD’s MULTI-ARRAY technology uses simple protocols, requires minimal sample, and quantifies analyte concentration over a wide dynamic range.


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IL-21 Multiplex Products

Our multiplex panels let you process up to 10 analytes simultaneously in each well of a MULTI-SPOT microplate. They provide the same outstanding performance as our singleplex immmunoassays while saving money, sample, and time.


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