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HelpTest ID RFPN Rheumatoid Factor Panel, Serum
Additional Testing Requirements
Rheumatoid factor (RF) IgA and RF IgM should be tested in combination with CCP / Cyclic Citrullinated Peptide Antibodies, IgG, Serum; or following positive or equivocal results for either RHUT / Rheumatoid Factor, Serum; or RAPAN / Rheumatoid Arthritis Panel, Serum.
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial.
Useful For
Evaluating patients at-risk of rheumatoid arthritis (RA) or features of inflammatory arthritis
Differentiating the antibody isotype profile in patients positive for rheumatoid factor (RF)
Aid in the risk stratification of RF-seropositive patients with RA
Highlights
This test is useful for the differentiation of rheumatoid factor (RF) antibodies based on the presence of IgM or IgA antibody isotypes in patients with or at-risk for rheumatoid arthritis (RA).
The combination of RF IgM and RF IgA results provides the highest sensitivity for RA while IgA isotype results provide the highest specificity and positive likelihood ratio for RA diagnosis. The presence of RF IgA isotype may also be relevant in the risk stratification of RA for erosive joint disease.
Together with anti-citrullinated peptide/protein IgG antibody testing, isotype analysis may be an alternative to RF testing.
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| RFA | Rheumatoid Factor IgA, S | No | Yes |
| RFM | Rheumatoid Factor IgM, S | No | Yes |
Method Name
Chemiluminescent Immunoassay
Reporting Name
Rheumatoid Factor Panel, SSpecimen Type
SerumSpecimen Minimum Volume
0.3 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 14 days | |
| Frozen | 28 days | ||
| Ambient | 48 hours |
Reference Values
RHEUMATOID FACTOR, IgA
Negative: <20 CU
Positive: ≥20 CU
Reference values apply to all ages.
RHEUMATOID FACTOR, IgM
Negative: <5.0 IU/mL
Positive: ≥5.0 IU/mL
Reference values apply to all ages.
Day(s) Performed
Wednesday
Report Available
2 to 7 daysPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86431 x2
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| RFPN | Rheumatoid Factor Panel, S | 106053-2 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| RFM | Rheumatoid Factor IgM, S | 9338-5 |
| RFA | Rheumatoid Factor IgA, S | 33313-8 |