May aid in prognostication for rheumatoid arthritis. Rheumatoid Arthritis Panel (2003277) is preferred for the workup of suspected rheumatoid arthritis or undifferentiated inflammatory arthritides.
Semi-Quantitative Enzyme-Linked Immunosorbent Assay
Mon, Wed, Fri
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)
Contaminated, hemolyzed, icteric, or lipemic specimens.
After separation from cells: Ambient: 48 hours; Refrigerated: 2 weeks; Frozen: 1 year (avoid repeated freeze/thaw cycles)
|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|
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.
|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|
- RF Abs
- RF IgA IgG IgM
- RF Isotypes