Anti-Carbamylated Protein (CarP) Antibody

CPT: 83516
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  • Anti-CarP antigen antibody
  • RA marker

Special Instructions

This test has not been approved for NY state clients.

Expected Turnaround Time

7 - 10 days

Specimen Requirements




1 mL

Minimum Volume

0.5 mL


Red-top tube; serum from red-top tube; serum from a gel tube; or serum gel tube


Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.

Storage Instructions

Refrigerate or freeze.

Stability Requirements



Room temperature

14 days


14 days


14 days

Freeze/thaw cycles

Stable x3

Test Details


Anti-CarP antibodies may be positive in about 10% of early RA patients who are RF-negative and anti-CCP-negative and may be present years before the onset of RA symptoms.1,2 Anti-CarP is associated with more active disease and higher risk of developing joint erosions.1 Anti-CarP levels especially in combination with RF- and Anti-CCP-positivity may predict joint erosion and radiographic progression.1


This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.


Enzyme-linked immunosorbent assay (ELISA)


1. 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: Data From the French ESPOIR Cohort. Arthritis Rheumatol. 2017 Dec;69(12):2292-2302.28853240
2. Brink M, Verheul MK, Rönnelid J,et al. Anti-carbamylated protein antibodies in the pre-symptomatic phase of rheumatoid arthritis, their relationship with multiple anti-citrulline peptide antibodies and association with radiological damage. Arthritis Res Ther. 2015 Feb 7;17(1):25.25889922


Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
520311 Anti-CarP Ab 66445-8 520312 Anti-CarP Ab Units 66445-8
Reflex Table for Anti-CarP Ab
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 000000

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