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Test Code 1433E 14-3-3 eta, Serum


Specimen Required


Supplies: Sarstedt Aliquot Tube 5 mL (T914)

Collection Container/Tube: Serum gel

Submission Container/Tube: Plastic vial

Specimen Volume: 0.5 mL Serum

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Useful For

A potentially improved approach for the early identification of patients at-risk for or with early and established rheumatoid arthritis (RA) in combination with specific autoantibody tests

 

This test is intended to be used as an aid in the early diagnosis of RA and management of the disease.

Method Name

Enzyme-Linked Immunosorbent Assay (ELISA)

Reporting Name

14-3-3 eta, S

Specimen Type

Serum SST

Specimen Minimum Volume

Serum: 0.4 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum SST Refrigerated (preferred) 14 days
  Frozen  100 days
  Ambient  48 hours

Reference Values

< 0.19 ng/mL

Interpretation

Serum 14-3-3 eta was tested in a clinically characterized rheumatoid arthritis (RA) and early RA patient Mayo Clinic patient cohort, where 275 of 446 patients (82.6%) were seropositive (defined as having 3rd generation anti-CCP IgG antibody [CCP3] >20 U and/or rheumatoid factor [RF] >14 IU/mL). A 14-3-3 eta cutoff of ≥0.19 ng/mL for both early and established RA patients was used to calculate the sensitivity and specificity of 14-3-3 eta for RA (n=113) and early RA (n=95).

 

Serum 14-3-3 eta slightly increased sensitivity for RA (87.0%) and early RA (75.8%) when used in concert with anti-CCP3 IgG and RF, versus the use of a combination of anti-CCP3 IgG and RF alone (RA sensitivity 82.6%, and early RA sensitivity 74.7%).

 

The addition of 14-3-3 eta offers an increase in specificity for RA (99.1%), and early RA (99.1%), relative to observed positivity with RF and anti-CCP3 IgG antibodies without the use of 14-3-3 eta (RA specificity 94.7%, and early RA specificity 94.7%).

 

Serum 14-3-3 eta concentration (ng/mL)

Qualitative Interpretation

<0.19

Negative

≥0.19-0.39

Mild positive

≥0.40-0.79

Moderate positive

≥0.80

Strong positive

Clinical Reference

1. Kilani RT, Maksymowych WP, Aitken A, et al. Detection of high levels of 2 specific isoforms of 14-3-3 proteins in synovial fluid from patients with joint inflammation. J Rheumatol. 2007;34(8):1650-1657

2. Maksymowych WP, Naides SJ, Bykerk V, et al. Serum 14-3-3 eta is a novel marker that complements current serological measurements to enhance detection of patients with rheumatoid arthritis. J Rheumatol. 2014;41(11):2104-2113

3. Guan SZ, Yang YQ, Bai X, et al. Serum 14-3-3 eta Could Improve the Diagnostic Rate of Rheumatoid Arthritis and Correlates to Disease Activity. Ann Clin Lab Sci. 2019;49(1):57-62

4. Subedi R, Misbah A, Najada AA, Ocon AJ. Evaluation of 14-3-3eta protein as a diagnostic biomarker in the initial assessment of inflammatory arthritis. J Rheum Dis. 2025;32(2):130-135

5. Shovman O, Gilburd B, Watad A, et al. The diagnostic value of 14-3-3 eta protein levels in patients with rheumatoid arthritis. Best Pract Res Clin Rheumatol. 2018;32(4):610-617

6. Maksymowych WP, Boire G, van Schaardenburg D, et al. 14-3-3? Autoantibodies: Diagnostic Use in Early Rheumatoid Arthritis. J Rheumatol. 2015;42(9):1587-1594

7. Carrier N, Marotta A, de Brum-Fernandes AJ, et al. Serum levels of 14-3-3 eta 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;18:37

8. Hammam N, Salah S, Kholef EF, Moussa EM, Marotta A. 14-3-3 eta Protein in serum and synovial fluid correlates with radiographic damage and progression in a longitudinal evaluation of patients with established rheumatoid arthritis. Mod Rheumatol. 2020;30(4):664-670

9. Nelson HA, Martins TB, Saadalla A, Nandakumar V. Evaluation of the clinical performance of anti-mutated citrullinated vimentin antibody and 14-3-3 eta testing in rheumatoid arthritis. Clin Chem Lab Med. 2024;63:790-796

Day(s) Performed

Wednesday

Report Available

3 to 9 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83520

LOINC Code Information

Test ID Test Order Name Order LOINC Value
1433E 14-3-3 eta, S 75880-5

 

Result ID Test Result Name Result LOINC Value
624066 14-3-3 eta, S 75880-5