ARUP's Laboratory Test Directory

Rheumatoid Factor : 0050465

Mnemonic: RA

Ordering Recommendation: Aids in the workup of suspected rheumatoid arthritis or undifferentiated inflammatory arthritides. Consider ordering this test in conjunction with Cyclic Citrullinated Peptide (CCP) Antibody, IgG (0055256) to increase specificity and sensitivity. Rheumatoid Arthritis Panel (2003277) is preferred test.
Methodology: Quantitative Immunoturbidimetry
Performed: Sun-Sat
Reported: Within 24 hours
Specimen Required: Patient Prep: Fasting specimen preferred.

Collect: Serum separator tube or plasma separator tube. Also acceptable: Green (sodium or lithium heparin), lavender (EDTA), or pink (K2EDTA).

Specimen Preparation: Allow specimen to clot completely at room temperature. Transfer 0.5 mL serum or plasma to an ARUP Standard Transport Tube. (Min: 0.5 mL)

Storage/Transport Temperature: Refrigerated.

Unacceptable Conditions: Body Fluid (refer to Rheumatoid Factor, Body Fluid, ARUP test code 2003347). Hemolyzed specimens.

Stability (collection to initiation of testing): After separation from cells: Ambient: 24 hours; Refrigerated: 1 week; Frozen: 2 weeks (should not be thawed more than once)

Reference Interval:
0-14 IU/mL
CPT Code(s): 86431
Cross References: RA (Rheumatoid Factor)