A multi-biomarker blood test for assessing level of 12 key proteins that have been associated with rheumatoid arthritis into one test that produces an objective, quantitative score related to disease activity.
The score ranges from 0-100, with a lower score indicates less disease activity.
The 12 proteins are:
VCAM-1 (vascular cell adhesion molecule-1) plays a role in the interaction between cells, blood vessels, and connective tissues contributing to the build up of inflammatory cells.
EGF (epidermal growth factor) is produced by cells in rheumatoid joint tissue promoting cell growth and inflammation.
VEGF-A (vascular endothelial growth factor A) is produced in inflamed rheumatoid joints promoting blood vessel formation, edema and bone erosion.
IL-6 drives inflammation, cartilage deterioration, and bone erosion associated with rheumatoid arthritis.
TNF-RI (tumor necrosis factor receptor, type 1) is a receptor for TNF-alpha, drives joint inflammation and destruction.
MMP-1 (matrix metalloproteinase-1 or collagenase-1), an enzyme that contributes to cartilage destruction.
MMP-3 (matrix metalloproteinase-3 or stromelysin-1), an enzyme that destroys components of cartilage.
YKL-40, a protein that helps regulate tissue remodeling and destruction.
Leptin, a hormone secreted by fat tissue, cells in the joint tissue, and bone. contributing to inflammation and regulates bone remodeling.
Resistin, hormone secreted by cells in the joint tissue and bone that contributes to inflammation and controls bone remodeling.
SAA (serum amyloid) is a protein produced by the liver and maybe joint tissue in response to inflammation, where it can activate tissue and immune cells.
CRP (C-reactive protein) is produced by the liver in response to inflammation.
A score of 45 to 100 indicates high level of disease activity; 30 to 44 indicates moderate disease activity; and 1 to 29 indicates a low level of disease activity.
The Vectra DA is not used to diagnose arthritis, but it evaluates disease activity.