Rheumatoid Factor by Turbidimetry, Synovial Fluid (RDL)
Use
The most consistent serologic finding in patients with Rheumatoid Arthritis is an increase in the concentration of RF IgM in blood and synovial fluid. RF by Turbidimetry is 95% IgM.
Special Instructions
The test uses turbidimetric analysis which is predominantly sensitive to the IgM isotype of RF, accounting for approximately 95% of RF detected by this method. Proper aseptic collection of the synovial fluid into an appropriate container is essential for accurate testing. The test requires 1 mL of synovial fluid; however, a minimum volume of 0.3 mL is accepted but does not allow for repeat testing. It is important to store specimens under recommended conditions to preserve stability and accuracy of results.
Limitations
The test is limited to the detection of RF IgM and may not account for RF of other isotypes. RF levels can be influenced by a variety of conditions besides rheumatoid arthritis, such as other autoimmune disorders, chronic infections, or cancers, leading to potential false-positive results. Gross hemolysis, bacterial contamination, and the presence of lipemic, icteric, or non-synovial body fluids in the sample are causes for rejection and can adversely affect test results. Storage conditions must be strictly followed to ensure the integrity and reliability of test results.
Methodology
Other
Biomarkers
LOINC Codes
- 30231-5
- 30231-5
Result Turnaround Time
7-14 days
Related Documents
For more information, please review the documents below
Specimen
Body Fluid
Volume
1 mL
Minimum Volume
0.3 mL
Container
Transport tube or other container
Collection Instructions
Collect synovial fluid aseptically into tube or other container.
Storage Instructions
Store frozen or refrigerated.
Causes for Rejection
Grossly hemolyzed; bacterial contamination; lipemic, icteric, non-synovial body fluids
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 7 days |
| Refrigerated | 14 days |
| Frozen | 60 days |
Other tests from different labs that may be relevant