Synonyms
- 14.3.3η Protein ETA
- Augurex
Expected Turnaround Time
6 - 12 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Related Documents
For more information, please view the literature below.
Rheumatoid Arthritis Testing With Better Performance Brochure
Specimen Requirements
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
Frozen
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 3 days |
Refrigerated | 3 days |
Frozen | 7 days |
Freeze/thaw cycles | Stable x6 |
Causes for Rejection
Hemolysis; lipemia
Test Details
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 determined, by LabCorp. It has not been cleared or approved by the US Food and Drug Administration (FDA).
Methodology
Enzyme-linked immunosorbent assay (ELISA)
Reference Interval
<0.2 ng/mL
Additional Information
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 | ||
Marker Positivity | Early RA | Established RA |
RF+ | 57 | 85 |
Anti-CCP+ | 59 | 79 |
14-3-3η+ | 64 | 77 |
Anti-CCP and RF+ | 72 | 88 |
14-3-3η+ and RF+ | 75 | 94 |
14-3-3η+ and anti-CCP+ | 72 | 96 |
14-3-3η+ and RF+ and anti-CCP+ | 78 | 96 |
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
Footnotes
1. Carrier N, Marotta A, de Brum Fernandes AJ, et al. Serum levels of 14-3-3η protein supplement C-reactive protein and rheumatoid arthritis-associated antibodies to predict clinical and radiographic outcomes in a prospective cohort of patients with recent-onset inflammatory polyarthritis. Arthritis Res Ther. 2016 Feb;18:37.26832367
2. Maksymowych WP, Naides SJ, Bykerk V, et al. Serum 14-3-3η is a novel marker that complements current serological measurements to enhance detection of patients with rheumatoid arthritis. J Rheumatol. 2014 Nov; 41(11):2014-2013.25128504
3. Maysymowych WP, van der Heijde D, Allaart CF, et al. 14-3-3η is a novel mediator associated with the pathogenesis of rheumatoid arthritis and joint damage. Arthritis Res Ther. 2014 Apr;16(2):R99.24751211
LOINC® Map
| Order Code | Order Code Name | Order Loinc | 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 |
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