The JOINTstat® test measures the levels of 14-3-3η protein in the blood.
The 14-3-3η (eta) protein is present in everyone, inside of cells. In RA, it moves from being inside of cells to the outside environment, known as the “extracellular space”, where it can be measured in the blood. When 14-3-3η is present in blood, it is believed to “switch on” immune cells causing them to release factors that are involved in promoting inflammation and joint destruction.
A positive JOINTstat® test complements a clinical assessment for the diagnosis of RA. Studies have shown that higher 14-3-3η levels correspond with more aggressive disease, because it induces inflammation and joint damage factors. Your 14-3-3η protein levels can change during the disease course and studies indicate that low or decreasing levels correspond with a more favorable outcome.