Ordering Recommendation
May aid in prognostication for rheumatoid arthritis. The Rheumatoid Arthritis Panel (3004055) is preferred for the workup of suspected rheumatoid arthritis or undifferentiated inflammatory arthritides.
Mnemonic
Methodology
Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Performed
Mon, Wed, Fri
Reported
1-4 days
New York DOH Approval Status
Specimen Required
Serum separator tube.
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)
Refrigerated.
Contaminated, hemolyzed, icteric, or lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
Reference Interval
Test Number |
Components |
Reference Interval |
---|---|---|
Rheumatoid Factor, IgG by ELISA | 6 Units or less | |
Rheumatoid Factor, IgM by ELISA | 6 Units or less | |
Rheumatoid Factor, IgA by ELISA | 6 Units or less |
Interpretive Data
The presence of all three rheumatoid factor (RF) isotypes at abnormal levels has high specificity for a diagnosis of rheumatoid arthritis (RA). However, the presence of RF isotypes in any combination may be found in a variety of conditions, including Sjogren syndrome and hepatitis infections.
FDA
Note
Hotline History
CPT Codes
83516 x3
Components
Component Test Code* | Component Chart Name | LOINC |
---|---|---|
0051299 | Rheumatoid Factor, IgG by ELISA | 33314-6 |
0051300 | Rheumatoid Factor, IgM by ELISA | 11573-3 |
0051301 | Rheumatoid Factor, IgA by ELISA | 33313-8 |
Aliases
- RF Abs
- RF IgA IgG IgM
- RF Isotypes
- RF3