Rheumatoid Factors, IgA, IgG, and IgM by ELISA
Also known as: RF PAN
Use
This test may aid in the prognostication for rheumatoid arthritis. The presence of all three rheumatoid factor (RF) isotypes at abnormal levels indicates high specificity for a diagnosis of rheumatoid arthritis. However, RF isotypes in any combination may also be present in various other conditions, such as Sjogren syndrome and hepatitis infections.
Special Instructions
Separate serum from cells as soon as possible or within 2 hours of collection. Transfer 0.5 mL serum to an ARUP Standard Transport Tube. Minimum volume required is 0.3 mL.
Limitations
The test may yield false negatives in cases where rheumatoid factors are not present at sufficiently high levels to be detected. False positives can occur due to cross-reactive conditions such as Sjogren syndrome or hepatitis infections, which can also present with abnormal RF isotype levels.
New York Approved
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 33314-6
- 11573-3
- 33313-8
Result Turnaround Time
1-4 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
0.5 mL
Minimum Volume
0.3 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Separate serum from cells ASAP or within 2 hours of collection. Transfer to the appropriate transport tube.
Storage Instructions
Refrigerated.
Causes for Rejection
Contaminated, hemolyzed, icteric, or lipemic specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 2 weeks |
| Frozen | 1 year |