Test/Investigation
C1 Inhibitor Functional
Site(s) or Laboratory offering Test/Investigation
Referral laboratory (Immunology)
Units
U/mL
Also Known as/Frequency of Test
C1 Inhibitor Functional
Indications
C1 esterase inhibitor deficiency is the most common complement deficiency resulting in hereditary angioedema. 85% of HAE results from a reduced level of the C1Inhibitor. Acquired C1 inhibitor deficiency may occur with B-cell lymphomas and some autoimmune diseases. Samples collected during an acute attack of angioedema due to C1 inhibitor deficiency are characterised by a low C4. A normal C4 level virtually excludes all forms of C1 inhibitor deficiency. Referred outside of EPA
Comments/Precautions
Referred outside of EPA
Sample type
EDTA
Turnaround times (TAT) Urgent/Routine/GP or OPD
2 weeks
Reference intervals (adult unless stated)
46 – 130 U/mL