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26166 Rheumatoid Factor, IgM

Rheumatoid Factor, IgM
Test Code: RA-IGM
Synonyms/Keywords

​​RA Factor, FR, Rheumatoid Arthritis

Useful For

​Diagnosis and prognosis of rheumatoid arthritis​

See the Mixed Connective Tissue Disease Panel Algorithm for suggested testing strategy. 

Specimen Requirements
Specimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
Serum​​Red Top Tube (RTT)​Serum Separator Tube (SST)​0.5 mL​0.4 mL​0.3 mL
Specimen Stability Information
Specimen TypeTemperatureTime
​Serum ​​Refrigerated​7 days
​Frozen ​4 weeks
Rejection Criteria
Gross hemolysis
​Gross lipemia
​Plasma samples
Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Marshfield​Monday through Friday​6-8 hours​Turbidimetric Method
Reference Range Information
Performing LocationReference Range
​Marshfield​<13 IU/mL
Interpretation

​Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. The presence of autoantibodies, such as rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA; tested as anti-cyclic citrullinated peptide [anti-CCP]) can precede clinical manifestation of RA by many years. The 2010 ACR rheumatoid arthritis classification criteria focus on the need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent individuals from reaching the chronic, erosive disease state exemplified in the 1987 RA criteria. It defines “definite RA” as a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains:

Number and site of involve joints (score range 0 – 5)
Serologic abnormality (score range 0 – 3)
Elevated acute-phase response (score range 0 – 1)
Symptom duration (2 levels; range score 0 – 1)

Negative: < = 13 IU/mL score = 0
Low Pos: > 13 to 39 IU/mL, score = 2
High Pos: > 40 IU/mL, score = 3

Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​86431​​1​Rheumatoid Factor, Quantitative​
Synonyms/Keywords

​​RA Factor, FR, Rheumatoid Arthritis

Ordering Applications
Ordering ApplicationDescription
COM​Rheumatoid Factor, IgM
If the ordering application you are looking for is not listed, contact your local laboratory for assistance.
Specimen Requirements
Specimen TypePreferred Container/TubeAcceptable Container/TubeSpecimen VolumeSpecimen Minimum Volume
(allows for 1 repeat)		Pediatric Minimum Volume
(no repeat)
Serum​​Red Top Tube (RTT)​Serum Separator Tube (SST)​0.5 mL​0.4 mL​0.3 mL
Specimen Stability Information
Specimen TypeTemperatureTime
​Serum ​​Refrigerated​7 days
​Frozen ​4 weeks
Rejection Criteria
Gross hemolysis
​Gross lipemia
​Plasma samples
Useful For

​Diagnosis and prognosis of rheumatoid arthritis​

See the Mixed Connective Tissue Disease Panel Algorithm for suggested testing strategy. 

Reference Range Information
Performing LocationReference Range
​Marshfield​<13 IU/mL
Interpretation

​Rheumatoid arthritis (RA) is an autoimmune disease characterized by chronic inflammation. The presence of autoantibodies, such as rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA; tested as anti-cyclic citrullinated peptide [anti-CCP]) can precede clinical manifestation of RA by many years. The 2010 ACR rheumatoid arthritis classification criteria focus on the need for earlier diagnosis and institution of effective disease-suppressing therapy to prevent individuals from reaching the chronic, erosive disease state exemplified in the 1987 RA criteria. It defines “definite RA” as a total score of 6 or greater (of a possible 10) from the individual scores in 4 domains:

Number and site of involve joints (score range 0 – 5)
Serologic abnormality (score range 0 – 3)
Elevated acute-phase response (score range 0 – 1)
Symptom duration (2 levels; range score 0 – 1)

Negative: < = 13 IU/mL score = 0
Low Pos: > 13 to 39 IU/mL, score = 2
High Pos: > 40 IU/mL, score = 3

For more information visit:
Performing Laboratory Information
Performing LocationDay(s) Test PerformedAnalytical TimeMethodology/Instrumentation
​Marshfield​Monday through Friday​6-8 hours​Turbidimetric Method
For billing questions, see Contacts
Outreach CPTs
CPTModifier
(if needed)		QuantityDescriptionComments
​86431​​1​Rheumatoid Factor, Quantitative​
For most current information refer to the Marshfield Laboratory online reference manual.