Rheumatoid Factor

Test Code

Alias/See Also

RF, Rheumatoid, Rheumatoid Factor

CPT Codes
86430

Preferred Specimen

SST (Gold)

Other Acceptable Specimens

Lt Green (PST) plasma
LAV (EDTA) plasma

Specimen Stability

Rheumatoid Factor is stable in serum or plasma for 1 day stored at 20-25°C, 8 days stored at 2 - 8°C, and 3 months stored at <= -20°C. Avoid repeated freezing and thawing of samples.

Setup Schedule

24x7

Reference Range

0-14 IU/mL

Clinical Significance

Rheumatoid factors (RF) are antibodies directed against antigenic determinants on the Fc fragment of IgG. These are usually IgM antibodies, but may be IgG, IgA, or IgE. Rheumatoid factor sensitivity in rheumatoid arthritis varies from 30% in population-based studies to 70-80% in hospital-based studies, where the disease tends to be more severe. Higher titers of RF are more specific for the diagnosis of rheumatoid arthritis (RA) and are more common in patients with rapidly progressive joint destruction.

A positive RF is also seen in autoimmune rheumatic diseases and in non-rheumatic conditions with variable frequency e.g. SLE, Sjogren’s syndrome, subacute bacterial endocarditis, and other bacterial infections, infectious hepatitis, chronic liver diseases, chronic active pulmonary diseases, parasitic infections, and viral infections.

Performing Laboratory
CRMC Laboratory

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.