Rheumatoid Factor (RF)

Rheumatology

Normal Reference Ranges

Adult

< 14 IU/mL

Pediatric

< 14 IU/mL

Clinical Significance

Autoantibody typically targeting the Fc portion of IgG. Used to help diagnose Rheumatoid Arthritis, though anti-CCP is more specific.

Causes of High

  • Rheumatoid Arthritis
  • Sjögren's syndrome
  • Lupus (SLE)
  • Chronic infections (Hepatitis C, Endocarditis)

Causes of Low

  • Normal finding