Immune System Biomarkers
Guide to testing and understanding — how dysregulated immunity contributes to chronic diseases including autoimmune disorders, cardiovascular disease, and neurodegeneration.
Why Immune Dysfunction Matters
The immune system extends beyond pathogen defense. Low-grade, persistent inflammation — known as inflammaging — drives many chronic illnesses and predicts disability onset. The system influences metabolism, cardiovascular health, neurology, and gut function through complex interactions.
Immune System Architecture
Innate Immunity
The first-line defense via neutrophils, macrophages, and acute-phase proteins like CRP. Fast but non-specific — responds to general threats within hours.
Adaptive Immunity
Slower, highly specific response involving T cells, B cells, and antibodies. Develops targeted defenses and immunological memory for future encounters.
Both branches require monitoring for comprehensive health assessment.
Key Immune Biomarkers
Inflammatory Markers
| Biomarker | Function | Clinical Significance |
|---|---|---|
| CRP | Systemic inflammation indicator | Levels > 2 mg/L significantly increase cardiovascular risk |
| IL-6 | Regulatory cytokine | Linked to frailty and metabolic dysfunction |
| TNF-α | Master inflammatory cytokine | Central to autoimmune disease processes |
Cellular Markers
| Biomarker | Function | Clinical Significance |
|---|---|---|
| WBC count | Overall immune cell activity | Elevated neutrophils = infection; low lymphocytes = immunosuppression |
| CD4/CD8 ratio | Adaptive immune balance | Ratios < 1 suggest immunosenescence |
| NK cell activity | Innate antiviral defense | Reflects innate immunity and tumor surveillance capacity |
Autoimmunity Indicators
- ANA (Antinuclear antibodies) — screening marker for systemic autoimmune conditions
- Rheumatoid factor & anti-CCP — specific to rheumatoid arthritis
- TPO-Ab (Thyroid peroxidase antibodies) — marker for autoimmune thyroid disease
Optimal vs. Normal Ranges
| Biomarker | Normal Range | Optimal Target |
|---|---|---|
| CRP | < 3 mg/L | < 1 mg/L |
| IL-6 | Variable | Persistent levels < 7 pg/mL |
| CD4/CD8 ratio | 1–3 | Balanced mid-range |
Life Stage Considerations
Immune biomarker patterns vary significantly across life stages:
- Children show higher normal lymphocyte counts as the adaptive immune system develops
- Pregnancy shifts immunity toward innate responses to protect the developing fetus
- Menopause increases IL-6 and CRP levels as hormonal protection wanes
- Aging causes immunosenescence — elevated baseline inflammation with reduced adaptive capacity
Longevity Connections
Elevated inflammatory markers predict earlier disability, cognitive decline, and mortality. Maintaining balanced biomarker levels throughout life appears protective for healthspan — the years of active, independent living.
Optimization Strategies
- Omega-3 rich nutrition — reduces inflammatory cytokine production
- Regular physical activity — moderate exercise enhances immune surveillance
- Adequate sleep — sleep deprivation elevates CRP within days
- Micronutrient sufficiency — vitamin D, zinc, and selenium support immune cell function
- Stress management — chronic psychological stress suppresses adaptive immunity while elevating inflammation
Why Testing Matters
Immune biomarker assessment helps identify hidden disease risk and guides preventive interventions — particularly for those with family histories of autoimmunity, cardiovascular disease, unexplained fatigue, or metabolic dysfunction.