Normal Reference Ranges
Adult
80 - 160 mg/dL
Pediatric
80 - 170 mg/dL
Clinical Significance
Major component of the complement cascade. Consumption (low levels) indicates active autoimmune or immune-complex mediated disease.
Causes of High
- Acute inflammation (Acute phase reactant)
Causes of Low
- Systemic Lupus Erythematosus (SLE) flare
- Post-streptococcal glomerulonephritis (PSGN)
- Sepsis
- Hereditary angioedema