Rheumatoid Factor by Turbidimetry (RDL)
Use
IgM‐RF is the main isotype identified by clinically available diagnostic assays for RF detection. The most consistent serological finding in patients with Rheumatoid Arthritis (RA) is an increase in the concentration of RF IgM in blood and synovial fluid.
Special Instructions
This test is part of ANA 12 Plus Profiles, RAdx3 (RheumAssure), RAdx5, Arthritis Profile (RLD) and ILDdx. Separate serum from cells within one hour of collection and transfer to a plastic tube before shipping. Submit separate frozen specimens for each test requested to avoid delays.
Limitations
This test specifically measures IgM-RF and does not account for other isotypes like IgA or IgG that can also be present in rheumatoid conditions. External factors such as infections or other autoimmune disorders can also elevate RF levels, potentially leading to false positives. Grossly hemolyzed specimens, bacterial contamination, and non-serum specimens are causes for test rejection, which can affect result integrity.
Methodology
Other
Biomarkers
LOINC Codes
- 11572-5
- 11572-5
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.3 mL
Container
Red-top tube or gel-barrier tube
Collection Instructions
Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping.
Storage Instructions
Refrigerate or freeze.
Causes for Rejection
Grossly hemolyzed; bacterial contamination; lipemic specimen; icteric specimen; non-serum specimen types
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 60 days |
Other tests from different labs that may be relevant