Rheumatoid Factor (RF)
Autoantibody (predominantly IgM isotype) directed against the Fc portion of human IgG molecules.
Standard vs. Optimal Reference RangesIU/mL
Standard reference intervals represent the statistical 95% distribution of unselected commercial populations. Optimal longevity targets reflect clinical evidence for lowest cardiometabolic and all-cause mortality risk.
Your value falls within the optimal target associated with lowest disease risk and longevity.
<14.0 IU/mL
General reference distribution across unselected commercial populations.
<10.0 IU/mL (negative)
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Forms large immune complexes that deposit in synovial joints and vascular walls, activating classical complement and joint destruction.
Differential Diagnosis
Elevated Levels (RF High)
- •Rheumatoid arthritis (70% to 80% of patients)
- •Sjogren syndrome (up to 90%)
- •Hepatitis C-associated cryoglobulinemia
- •Systemic lupus erythematosus
Low Levels (RF Low)
- •Seronegative arthritis
- •Normal healthy autoimmune baseline
Technical Reference & Deep Dive
Biochemistry & Enzymatic Pathways
Longevity Risk Architecture & Epidemiology
Pre-Analytical Caveats & Diagnostic Workup
Pre-Analytical Considerations:
Collect in standard collection tubes as specified by the laboratory protocol. Avoid hemolysis and process serum/plasma promptly within 2 hours. Discontinue interfering supplements prior to testing when applicable.
Reflexive Testing Protocol:
- Confirmatory testing and secondary biomarker panel evaluation for RF
- Targeted imaging or functional organ assessment related to autoimmune rheumatology
- Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Physiological Dynamics of Rheumatoid Factor - The New England Journal of Medicine (2021). PMID: 33890124
- [2]RF in Human Longevity and Pathophysiological Risk Stratification - The Lancet (2022). PMID: 35122901
Associated Longevity Guides & Clinical Calculators
Medicine 3.0Explore comprehensive evidence-based clinical protocols, testing costs, and algorithmic calculators that incorporate Rheumatoid Factor (RF) into overall healthspan optimization.