Rheumatoid Factor (RF)
Also known as: RA Latex, Turbidimetry, RF Titer, Rheumatoid Factor (RF)
Use
Help in the differential diagnosis and prognosis of arthritic disorders
Special Instructions
The presence of rheumatoid factor, particularly in low titer, is not definitive for rheumatoid arthritis diagnosis. The presence of IgM RFs is reported in up to 10% of the normal population without clinical illness.
Limitations
Markedly lipemic or contaminated specimens may yield false-positive results. Other chronic inflammatory processes can also produce rheumatoid factors, which might be detected in synovial, pleural, and pericardial fluids but add little to serum test results. False-positives might also occur with assays using latex beads coated with human IgG.
Methodology
Immunoassay (Turbidimetry)
Biomarkers
LOINC Codes
- 11572-5
- 11572-5
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Red-top tube, gel-barrier tube, lavender-top (EDTA) tube, or green-top (heparin) tube
Storage Instructions
Maintain specimen at room temperature.
Causes for Rejection
Hemolysis; lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 14 days |
| Refrigerated | 14 days |
| Frozen | 14 days |
Other tests from different labs that may be relevant