Ordering Recommendation

May aid in the workup of suspected rheumatoid arthritis or undifferentiated inflammatory arthritides. The preferred test is Rheumatoid Arthritis Panel (3016634).

New York DOH Approval Status

This test is New York state approved.

Specimen Required

Patient Preparation
Collect

Serum separator tube.

Specimen Preparation

Separate serum from cells ASAP or within 2 hours of collection. Transfer 0.5 mL serum to an ARUP standard transport tube. (Min: 0.3 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions

Contaminated, heat-inactivated, hemolyzed, icteric, or lipemic specimens.

Remarks
Stability

After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 month (avoid repeated freeze/thaw cycles)

Methodology

Semi-Quantitative Enzyme-Linked Immunosorbent Assay

Performed

Mon, Wed, Fri

Reported

1-4 days

Reference Interval

0-19 Units

Interpretive Data

Anti-carbamylated protein (anti-CarP) IgG antibodies are present in about 34-53 percent of patients with RA, have specificities of greater than 90 percent and can occur in RA patients seronegative for both rheumatoid factor and anti-CCP. These autoantibodies may be present in the preclinical phase of disease, are associated with future RA development, and may predict radiographic joint destruction. Patients with weak positive results should be monitored and testing repeated.

Compliance Category

Analyte Specific Reagent (ASR)

Note

Hotline History

N/A

CPT Codes

83516

Components

Component Test Code* Component Chart Name LOINC
3003993 Carbamylated Protein Antibody, IgG
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Aliases

  • CarP IgG
  • Carbamylated protein IgG
Carbamylated Protein (CarP) Antibody, IgG