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 rheumatoid factor (RF) isotypes has a specificity of 99% for RA. However, RF in any isotype combination may be found in hepatitis C, Sjsyndrome, and other chronic infections.
|
| CPT Code(s): |
86430 x2 RF IgG/IgA; 86431 RF IgM
|
Cross References: |
RF Isotypes (Rheumatoid Factors, IgA, IgG, and IgM by ELISA), RF3 (Rheumatoid Factors, IgA, IgG, and IgM by ELISA) |