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Specimen Type: Serum, Inquire for additional option(s)
Optimum Volume: 0.5mL
|5 days||6 months||2.3 years|
Reporting units: pg/mL
Biological or Clinical Significance:
The biological activities of IL-2 are mediated by its binding to a multi-molecular cellular receptor complex. The receptor consists of three glycoprotein chains, an alpha chain (IL-2 Rα), a beta chain (IL-2 Rβ), and a gamma chain (IL-2 R α) which act together to form a high affinity receptor that transduce the IL-2 signal. The gamma chain has only more recently been shown to be necessary for high affinity binding, ligand internalization and signaling. A model of the IL-2 receptor complex would describe the high affinity receptor as an aß? trimer, in which all three chains are in contact with the ligand. Alone, IL-2 Ra binds IL-2 with low affinity, but is unable to transduce a signal. A soluble form of IL-2 Rα appears in serum, concomitant with its increased expression on cells. The function of the soluble IL-2 Rα is unclear , but increased levels of the soluble IL-2 Rα in biological fluids reportedly correlate with increased immune system activation. Results of a number of studies suggest a correlation of levels of IL-2 sRα in serum with activity of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosis (SLE).
Principle of Test Method:
The IL-2ra method is a solid phase ELISA designed to measure IL-2ra in cell culture supernates, serum and plasma. This assay employs the quantitative sandwich enzyme immunoassay technique.
1. Aziz N, Nishanian P, Mitsuyasu R, Detels R, Fahey JL. Variables that affect assays for plasma cytokines and soluble activation markers. Clin Diagn Lab Immunol 1999; 6:89-95