Specimen transport: At room temperature
Repeat frequency: At significant change of
Special precautions: None
Normal reference range: < 20 kIU/L
Volume and sample type: 7ml clotted blood
Turnaround time (calendar days from sample
receipt to authorised result): Median - 1, 95th percentile - 5
Indications for the test: Aid for the prognosis
of RA and Sjögren's syndrome in the presence of an erosive
Rheumatoid factor is not useful in the diagnosis of rheumatoid
arthritis, it has a limited role in predicting the risk of
complications particularly vasculitis.
Factors affecting the test: Disease activity:
only 70-80% of patients with confirmed RA have positive rheumatoid
factor. Detected in 2-10% of general population.
Elevated titres may also accompany a variety of acute immune
responses particularly infections (50%), liver disease,
Sarcoidosis, and SLE.
Clinical workstation reference: RH FACTOR
(Last updated October 7th