Rheumatoid Factor Isotypes, IgG, IgA, and IgM by EIA (RDL)
Use
EIA methods have the added advantage of being able to simultaneously detect RF of IgG and IgA subclasses in addition to RF IgM and are not susceptible to prozone. It has become apparent that the specificity and predictive value of the RF test is substantially increased by the detection of all three RF isotypes.
Special Instructions
Ensure to separate serum from cells within one hour of collection and transfer the serum to a plastic transport tube before shipping. This step is crucial to maintain the integrity of the specimen to yield accurate results. It is important to follow the collection and transport instructions meticulously to prevent any pre-analytical errors.
Limitations
The test may not detect all RF positive samples, as the presence of rheumatoid factor is not exclusive to rheumatoid arthritis and may be present in other conditions or in healthy individuals. Prozone effect is not a concern with this EIA method, unlike other methods which can miss high antibody titers.
Methodology
Immunoassay (ELISA)
Biomarkers
LOINC Codes
- 33313-8
- 33314-6
- 9338-5
- 33314-6
- 33313-8
- 9338-5
Result Turnaround Time
14-21 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
4 mL
Minimum Volume
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.
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 |
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