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14.3.3 eta, Rheumatoid Arthritis
- 14.3.3η Protein ETA
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.
This test was developed, and its performance characteristics determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).
Enzyme-linked immunosorbent assay (ELISA)
14-3-3 eta is highly specific for RA. Serum 14-3-3 eta may be especially helpful in identifying patients with early RA where it provides a 15% incremental benefit to the diagnostic sensitivity of markers, Rheumatoid Arthritis (RA) Factor and Cyclic Citrullinated Peptide (CCP) Antibodies.1 See table.
Diagnostic sensitivity: Complementarity between diagnostic markers (14-3-3η, RF and anti-CCP) in patients with early and established RA. Table 3A2
RF: rheumatoid factor, anti-CCP: anticitrullinated protein antibodies, RA: rheumatoid arthritis
Anti-CCP and RF+
14-3-3η+ and RF+
14-3-3η+ and anti-CCP+
14-3-3η+ and RF+ and anti-CCP+
Positive serum 14-3-3 eta levels are associated with higher rates of joint damage as measured by radiographic assessments (Sharp/van der Heijde Score).3
0.5 mL (Note: This volume does not allow for repeat testing).
Serum must be separated from cells within 45 minutes of venipuncture. Send serum in a plastic transfer tube.
Causes for Rejection
|Order Code||Order Code Name||Result Code||Result Code Name||UofM||Result LOINC|
|504550||14.3.3 ETA, Rheum. Arthritis||504551||14.3.3 ETA, Rheum. Arthritis||ng/mL||75880-5|
|504550||14.3.3 ETA, Rheum. Arthritis||504552||14.3.3 ETA, Rheum. Arthritis||N/A|