Normal Reference Ranges
Adult
70 - 130 %
Pediatric
70 - 130 %
Clinical Significance
Measures functional activity of C1 inhibitor. Low functional activity leads to uncontrolled bradykinin release, resulting in recurrent life-threatening attacks of angioedema.
Causes of High
- Acute phase reactant (inflammation)
Causes of Low
- Hereditary Angioedema (Type I and II)
- Acquired angioedema (associated with lymphoproliferative disorders)