Complement C1 esterase inhibitor – antigenic
| Category | Immunology |
|---|---|
| Test background |
C1 inhibitor deficiency causes hereditary angioedema (HAE). Patients present with acute deep tissue oedema, typically of the face, larynx or abdomen, which can be life threatening if respiratory obstruction occurs. 85 % of HAE patients have low antigenic C1 esterase inhibitor levels (type I HAE). The C4 level is low, especially during attacks. Request alongside C3 and C4 levels, plus C1 functional activity. |
| Clinical Indications |
Recurrent angioedema, laryngeal oedema, or abdominal pain in the absence of urticaria Family history |
| Reference range | 0.22-0.38 g/L |
| Sample & container required | RST (rust top) Separate and freeze immediately Transport frozen |
| Sample volume | 5-10 mL (1 mL serum) |
| Turnaround time | 21 days |