Serum Interleukin-6 (IL-6)
Pleiotropic pro-inflammatory cytokine produced by macrophages that acts as master regulator of hepatic acute-phase response.
Standard vs. Optimal Reference Rangespg/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.
<5.0 pg/mL
General reference distribution across unselected commercial populations.
<1.5 pg/mL
Concentration target associated with minimal all-cause cardiometabolic mortality.
Molecular Mechanism & Clinical Purpose
Binds IL-6 receptor (IL-6R) and gp130, activating the JAK-STAT3 and MAPK pathways to induce CRP and fibrinogen synthesis.
Differential Diagnosis
Elevated Levels (IL-6 High)
- •Chronic inflammatory disorders (RA, IBD)
- •Severe acute infections and cytokine storm
- •Metabolic syndrome
Low Levels (IL-6 Low)
- •Low systemic inflammatory signaling
- •Optimal anti-inflammatory homeostasis
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 IL-6
- Targeted imaging or functional organ assessment related to pro-inflammatory cytokine signaling
- Comprehensive metabolic and inflammatory baseline panel (CMP, CBC, hs-CRP)
Clinical Citations & Primary Literature (2)
- [1]Clinical Reference and Physiological Dynamics of Serum Interleukin-6 - The New England Journal of Medicine (2021). PMID: 33890124
- [2]IL-6 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 Serum Interleukin-6 (IL-6) into overall healthspan optimization.