C1 Esterase Inhibitor
Diagnosis of hereditary angioedema (HAE). C1 esterase inhibitor
deficiency is the commonest of the inherited complement
deficiencies (approx. 1:50,000) and is autosomal dominant. Several
members of a family are usually affected.
Functional C1 esterase
inhibitor, C3 and C4 levels.
Request on ICE
Analysed by referral laboratory if specific criteria met.
Investigation of hereditary angioedema. Usually C1 esterase
inhibitor analysis will only be undertaken C4 levels are low with
normal C3 levels.
The request form should show:
- Site, duration, frequency and clinical nature of attacks
- Details of relatives similarly affected
The sample WILL NOT be analysed if insufficient clinical
information is provided or if the clinical details provided suggest
an inappropriate request. Samples not analysed will be stored
for 1 month and the laboratory must be contacted if there is a
specific reason for requiring the test.
Sent to referral lab (Barts & Royal London)
Causes for Rejection
Unlabelled or incorrectly labelled sample; not meeting specific
criteria for analysis; inadequate clinical information.
Adult: 0.15 - 0.35 g/L