Reference Interval:
| Test Number
| Components
| Reference Interval
| | | Rheumatoid Factor, IgG by EIA
| Less than 21 U/mL
| | | Rheumatoid Factor, IgM by EIA
| Less than 26 IU/mL
| | | Rheumatoid Factor, IgA by EIA
| Less than 36 U/mL
|
|
| Interpretive Data: |
The presence of abnormal levels of all three RF isotypes has a specificity of 99% for RA. However, RF in any isotype combination may be found in hepatitis C, Sjögren's syndrome and other chronic infections.
|
| CPT Code(s): |
86430 x2 RF IgG/IgA; 86431 RF IgM
|
|