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
Clinical Focus
Autoimmune Rheumatic and Related DiseasesTest 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