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Specimen Type: Heparin Plasma, Inquire for additional option(s)
Optimum Volume: 0.5 mL
|2 days||11 days||11 months|
Reporting units: mg/dL
Biological or Clinical Significance:
E-Selectin (Endothelial Leukocyte Adhesion Molecule-1, ELAM-1, CD62E) is a 115 kDa, type-1 transmembrane glycoprotein expressed only on endothelial cells and only after activation by inflammatory cytokines (IL-1 P, TNF-a) or endotoxin. Expression is transitory, reaching a maximum within about 6 hours after stimulation and then declining, with shedding of soluble E-Selectin. Cell-surface E-Selectin is a mediator of the rolling attachment of leukocytes to the endothelium, an essential step in extravasation of leukocytes at the site of inflammation, thereby playing a key role in localized inflammatory response. E-Selectin is believed to be particularly important in inflammation involving the skin.
The extracellular part of E-Selectin includes a calcium-dependent C2-type lectin domain, an epidermal growth factor (EGF) domain, and six repeats of a complement-regulatory-protein-like sequence. E-Selectin binds sialyl Lewis X (sLex), a sialic acid-galactose-Nacetylglucosamine-fructose tetrasaccharide, but the actual recognition is thought to be for a specific presentation of those glycosyl units in a precise three-dimensional configuration on a specific glycoprotein rather than for that particular carbohydrate.
Soluble E-Selectin is found in the blood of healthy individuals, probably arising from proteolytic cleavage of the surface-expressed molecule. Elevated levels of sE-Selectin in serum have been reported in a variety of pathological conditions. Although it might be anticipated that sE-Selectin would suppress leukocyte migration by competing with surface-associated E-Selectin, it may actually activate neutrophils and act as a pro-inflammatory agent.
Principle of Test Method: The e-selectin assay is a solid phase ELISA designed to measure soluble e-selectin in cell culture supernates, serum, and plasma.
1. Hartweg J, Gunter M, Perera R, Farmer A, Cull C, Schalkwijk C, Kok A, Twaalfhoven H, Holman R, Neil A. Stability of soluble adhesion molecules, selectins, and C-reactive protein at various temperatures: Implications for epidemiological and large-scale clinical studies. Clin Chem. 2007; 53:1858-60.