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Test Code RHUTSO Rheumatoid Factor, Serum

Important Note

This is the alternative test to replace the current inhouse tests CTDP and RA-IGM which are temporarily unavailable due to a reagent backorder.

Additional Codes

Mayo Test Code:  RHUT

Reporting Name

Rheumatoid Factor, S

Useful For

Diagnosis and prognosis of rheumatoid arthritis

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Serum


Additional Testing Requirements


An alternative or complementary assay to rheumatoid factor (RF) that has demonstrated utility in the diagnosis and assessment of rheumatoid arthritis (RA) is CCP / Cyclic Citrullinated Peptide Antibodies, IgG, Serum. Utilization of both tests can provide clinical value in the diagnosis of RA. RF is not specific and may be present in other inflammatory rheumatic diseases and nonrheumatic diseases as well as in nonaffected individuals, especially in those 60 years of age or older.



Specimen Required


Supplies: Sarstedt Aliquot Tube, 5 mL (T914)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL serum

Collection Instructions: Centrifuge and aliquot serum into a plastic vial.


Specimen Minimum Volume

Serum: 0.75 mL

Specimen Stability Information

Specimen Type Temperature Time
Serum Refrigerated (preferred) 14 days
  Ambient  14 days
  Frozen  14 days

Reference Values

<15 IU/mL

Day(s) Performed

Monday through Friday

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

LOINC Code Information

Test ID Test Order Name Order LOINC Value
RHUT Rheumatoid Factor, S 11572-5

 

Result ID Test Result Name Result LOINC Value
RHUT Rheumatoid Factor, S 11572-5

Cautions

Nonrheumatoid and rheumatoid arthritis (RA) populations are not clearly separate with regard to the presence of rheumatoid factor (RF) (15% of RA patients have a nonreactive titer and 8% of nonrheumatoid patients have a positive titer). Patients with various nonrheumatoid diseases characterized by chronic inflammation may test positive for RF. These diseases include systemic lupus erythematosus, polymyositis, tuberculosis, syphilis, viral hepatitis, infectious mononucleosis, and influenza. RF factor antibodies have been observed in non-affected individuals, particularly in patients aged 60 years or older.

Report Available

1 to 3 days

Specimen Retention Time

14 days

Reject Due To

Gross hemolysis Reject
Gross lipemia OK
Gross icterus OK

Method Name

Turbidimetry

Forms

If not ordering electronically, complete, print, and send 1 of the following forms with the specimen:

-Kidney Transplant Test Request

-Renal Diagnostics Test Request (T830)

Testing Algorithm

For more information see Connective Tissue Disease Cascade.

Special Instructions