RHEUMATOID FACTOR - serum

---

Specimen: 5 mL blood in plain tube.

Method: Agglutination of gamma globulin-coated latex particles or erythrocytes; nephelometry; turbidimetry.

Reference Interval: <30 IU/L.

Application: Diagnosis and prognosis of rheumatoid arthritis; also positive in other chronic inflammatory conditions and immune complex diseases.

Interpretation: Patients with rheumatoid arthritis and high levels of rheumatoid factor tend to have more aggressive disease with extra-articular manifestations.

Reference: Walker DT. Ann Rheum Dis 1986; 45: 684-690.

---