Use: 14-3-3 eta protein is a joint-derived, proinflammatory mediator that is implicated in the joint erosion process and pathogenesis of RA. Serum 14-3-3 eta is elevated in both early and established RA.

Limitations: This test was developed, and its performance characteristics were determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).

Methodology: Enzyme-linked immunosorbent assay (ELISA)

Specimen: Serum, frozen

Volume: 1 mL

Minimum Volume: 0.5 mL (Note: This volume does not allow for repeat testing).

Container: Red-top tube or gel-barrier tube

Collection: Serum must be separated from cells within 45 minutes of venipuncture. Send serum in a plastic transfer tube.

Storage Instructions: Refrigerate. Stable at room temperature or refrigerated for three days. Frozen for seven days. Freeze/thaw cycles x6.

Causes for Rejection: Hemolysis; lipemia