Rheumatoid Factor (IgA, IgG, IgM)
Test Code
19705
83520 (x3)
Clinical Significance
Rheumatoid Factor (IgA, IgG, IgM) -
The concentration of RF tends to be highest when the disease peaks and tends to decrease during prolonged remission. RF IgM is found in 1 to 4% of the general population. RF is present in 75% of adult RA patients with the highest incidence of RF occurring in persons over 65 years of age. Increased RF levels may also accompany a variety of acute immune responses, particularly viral infections and a number of liver diseases (infectious mononucleosis, tuberculosis, leprosy, various parasitic diseases, liver disease, sarcoidosis, and systemic ...
Test Resources
Test Details
Overnight fasting is preferred
Methodology
Immunoassay (IA)
Reference Range(s)
| Rhematoid Factor (IgA) |
| ≤6 Negative |
| >6 Positive |
| Rhematoid Factor (IgG) |
| ≤6 Negative |
| >6 Positive |
| Rhematoid Factor (IgM) |
| ≤6 Negative |
| >6 Positive |
Alternative Name(s)
RF,RA,Rheumatoid arthritis
Preferred Specimen(s)
1.8 mL serum
Minimum Volume
0.9 mL
Transport Container
Transport tube
Transport Temperature
Refrigerated (cold packs)
Specimen Stability
- Room temperature: 48 hours
- Refrigerated: 8 days
- Frozen: 28 days
Reject Criteria
Gross hemolysis • Grossly lipemic • Grossly icteric • Heat treated samples
Setup Schedule
1.8 mL serum
0.9 mL
Transport tube
Refrigerated (cold packs)
Room temperature: 48 hours
Refrigerated: 8 days
Frozen: 28 days
Refrigerated: 8 days
Frozen: 28 days
Gross hemolysis • Grossly lipemic • Grossly icteric • Heat treated samples