Test Includes
14-3-3 eta protein; Anti-CEP1 (citrullinated alpha-enolase 1) Ab; Anti-Sa (citrullinated vimentin) Ab; Anti-CarP (carbamylated protein) Ab
Expected Turnaround Time
7 - 10 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: Novel Serologic Markers White Paper
Rheumatoid Arthritis Testing With Better Performance Brochure
Specimen Requirements
Specimen
Serum
Volume
3 mL
Minimum Volume
1.5 mL (Note: This volume does not allow for repeat testing.)
Container
Red-top tube or gel-barrier tube
Collection
Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.
Storage Instructions
Refrigerate.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 7 days |
Refrigerated | 14 days |
Frozen | 60 days |
Freeze/thaw cycles | Stable x1 |
Causes for Rejection
Grossly hemolyzed; bacterial contamination; lipemic, icteric, non-serum specimen types
Test Details
Use
SeroNeg RAdx4 is a diagnostic and prognostic panel for Rheumatoid Arthritis designed to complement traditional RF and Anti-CCP testing.
This profile, consisting of 14-3-3 eta protein, Anti-CEP1 (citrullinated alphaenolase 1) Ab, Anti-Sa (citrullinated vimentin) Ab, and the novel Anti-CarP (carbamylated protein) Ab, enhances the diagnosis of established or early RA (especially in individuals seronegative for RF and Anti-CCP Ab) and may also help predict disease severity.
Decrease in 14-3-3 eta and/or Anti-Sa Ab with treatment is associated with less radiographic progression. The presence of Anti-CEP1 and Anti-CCP Antibodies suggests the imminent progression of pre-clinical RA into clinical RA. Anti-CarP may predict the development of RA independently of Anti-CCP and may be present years before the onset of symptoms in RA. Anti-CarP may confer a 10% incremental benefit in identify early RA and is associated with more active disease and higher risk of developing joint erosions.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Methodology
Enzyme-linked immunosorbent assay (ELISA)
References
Truchetet ME, Dublanc S, Barnetche T, et al. Association of the Presence of Anti- Carbamylated Protein Antibodies in Early Arthritis with a Poorer Clinical and Radiologic Outcome. Arthritis Rheumatol. 2017 Dec;69(12):2292-2302.28853240
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 520305 | SeroNeg RAdx4 Profile | 520206 | 14.3.3 ETA, Rheum. Arthritis | ng/mL | 75880-5 | |
| 520305 | SeroNeg RAdx4 Profile | 520207 | Anti-CEP-1 Ab, IgG (RDL) | Units | 96561-6 | |
| 520305 | SeroNeg RAdx4 Profile | 520208 | Anti-Sa Ab, IgG (RDL) | Units | 54022-9 | |
| 520305 | SeroNeg RAdx4 Profile | 520317 | Anti-CarP Ab | Units | 66445-8 |
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