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Epic Test Code LAB206 Rheumatoid Factor

Performing Location(s)

BMC

Synonyms

RA, RF

Specimen Type

Serum

Preferred Container

Gold top tube

Alternate Container

Red top tube

Minimum Volume to Submit for Testing

1 mL Serum

  • Multiple test can be performed from this volume. For question please contact the lab at 547-3975.  

Storage Requirements

Sample tubes should be centrifuged within 2 hour of collection followed by transfer of the serum (red) or plasma (green top) to a labeled plastic, aliquot tube.

Gold tops do not need to be aliquoted

See Causes of Rejection for temperature requirements.

Transportation Needs

Deliver specimen to laboratory within 1 hour of collection if unspun. If not possible see "storage Requirements". 

Causes for Rejection

Mislabeled or unlabeled specimen
Less than 50% draw for Vacutainer tubes
> 8 days Refrigerated (Serum tubes are routinely stored at the lab for only 7 days therefore, an add-on may not be possible after 7 days.)
> 24 hours Room Temp
> 3 months Frozen
Hemolysis > 500 mg/dL HgB
Lipemia > 750 mg/dL Trig
Bilirubin > 40 mg/dL Bili

Limitations

Although a positive Rheumatoid Factor is highly suggestive of rheumatoid arthritis, it is not diagnostic for this condition since RF also appears in a small percentage of helathy individuals and in some patients with other disorders
Fresh serum is the best specimen type. Although plasma can be used, it is not optimal

Reference Values

Population Units Reference Range
All Populations IU/mL 0 <14

A negative result does not exclude rheumatoid arthritis. Conversely, certain non-rheumatoid 
conditions may elicit a positive results. Interpret in conjunction with other clinical findings.

Days of Analysis

All

Available STAT

Yes

Additional Information

Please refer to Rheumatoid Factor Test Change Memo March 25, 2014

Methodology

Beckman AU/Dx Series

CPT Code

86431

Last Updated

27-NOV-24 MS