CPT: 83520; 86200; 86431
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  • 14-3-3
  • 14-3-3 η Protein
  • ACPA
  • Anti-CCP
  • Anticitrullinated Protein Antibody
  • Augurex
  • CCP
  • eta
  • IdentRA
  • RF
  • RF Titer
  • Rheumatoid Factor

Expected Turnaround Time

8 - 12 days

Related Information

Specimen Requirements




2 mL

Minimum Volume

0.8 mL


Red-top or gel-barrier tube

Storage Instructions

Frozen preferred, refrigerate acceptable

Stability Requirements



Room temperature

3 days


3 days


14 days

Freeze/thaw cycles

Stable x3

Test Details


Aid in the diagnosis of rheumatoid arthritis (RA)1,2


Results of this panel should be used in conjunction with clinical findings and other laboratory tests.

"It is acknowledged that an individual patient may meet the definition of RA without requiring that all tests be performed. For example, patients with a sufficient number of joints involved and longer duration of symptoms will meet criteria regardless of their serologic or acute-phase response status. The classification criteria can be applied to any patient or otherwise healthy individual, as long as 2 mandatory requirements are met: First, there must be evidence of currently active clinical synovitis (i.e., swelling) in at least 1 joint as determined by an expert assessor. Second, the criteria may be applied only to those patients in whom the observed synovitis is not better explained by another diagnosis."6


RA Factor: Immunoturbidimetry

CCP Antibodies: ELISA

14-3-3 eta protein: ELISA

Reference Interval

• RA Factor:<14 IU/mL

• CCP Antibodies IgG, IgA: Units

Negative: <20

Weak positive: 20 - 39

Moderate positive: 40 - 59

Strong positive: >59

• 14-3-3 eta protein: <0.2 ng/mL

Additional Information

This RheumAssure panel is comprised of three tests: RA Factor, CCP Antibodies, and 14-3-3 eta protein.

Used together, these three markers are able to diagnose established RA with a sensitivity of 88-96% and early RA with a sensitivity of 78- 92%.1,2

RA factor (also called RF) is elevated in established RA (sensitivity 72-85%)2,3 and in early RA (sensitivity 44-63%).1,4 Its specificity for RA is 80%.3

CCP Antibodies have similar sensitivities for established RA (66-79%) and early RA (59%)2,3 but higher specificity (90-96%).3,5

Serum 14-3-3 eta protein is elevated in both established RA (sensitivity 77%) and early RA (sensitivity 59-64%).1,2 It may provide a 15-20% incremental benefit in identifying early RA.1,4

Therefore, elevation of one or more markers of RheumAssure is consistent with a diagnosis of rheumatoid arthritis. When all three markers are negative, an RA diagnosis is less likely.


1. Maksymowych WP, Boire G, van Schaardenburg D, et al. 14-3-3η Autoantibodies: Diagnostic Use in Early Rheumatoid Arthritis. J Rheumatol 2015;42(9):1587-1594.26178283
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;41(11):2104-2113.25128504
3. Lee DM, Schur PH. Clinical utility of the anti-CCP assay in patients with rheumatic diseases. Ann Rheum Dis 2003 Sep;62(9):870-874.12922961
4. 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 1;18:37.26832367
5. Dubucquoi S, Solau-Gervais E, Lefranc D, et al. Evaluation of anti-citrullinated filaggrin antibodies as hallmarks for the diagnosis of rheumatic diseases. Ann Rheum Dis 2004 Apr;63(4):415-419.15020336
6. American College of Rheumatology. The 2010 ACR-EULAR Classification Criteria for Rheumatoid Arthritis. http://www.rheumatology.org/practice/clinical/classification/ra/ra_2010.asp. Accessed June 20, 2014.


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
504509 RheumAssure 504560 Rheumatoid Arthritis Factor Units/mL 11572-5
504509 RheumAssure 504554 CCP Antibodies IgG/IgA Units 57093-7
504509 RheumAssure 504551 14.3.3 ETA, Rheum. Arthritis ng/mL 75880-5

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