RF Rapid Quantitative Test (Fluorescence Immunoassay)

The Biotime RF Rapid Quantitative Test is intended to quantify the concentration of RF in human serum, plasma, and whole blood on the Biotime FIA Analyzer by fluorescent immunoassay. The test is used as an aid in the detection of rheumatoid arthritis.

-Fluorescence immunoassay

-Rheumatoid arthritis

For in vitro diagnostic use only. For professional use only.

Specification

Clinical Significance:

Traditional autoantibody marker for Rheumatoid Arthritis

Part of 2010 ACR/EULAR classification criteria for RA

Associated with disease severity and extra-articular manifestations

Key Points:

Sensitivity for RA: ~70–80%

Specificity for RA: Limited (~60–70%) – can be positive in:

Other autoimmune diseases (SLE, Sjögren's syndrome, scleroderma)

Chronic infections (hepatitis, TB, endocarditis)

Malignancies

1–5% of healthy individuals (increases with age)

Higher RF titers correlate with:

More severe disease

Presence of rheumatoid nodules

Vasculitis

Poorer prognosis

Negative RF does not exclude RA (seronegative RA)