C1 esterase inhibitor functional test
Specimen transport: All samples from outside
the hospital should be transported on an ice pack. Transport at
temperature is acceptable within this hospital if the sample is
delivered to the Immunology laboratory within 3 hours.
Repeat frequency: At significant change of
clinical symptoms, monitoring of treatment.
Special precautions: The correct sample tube
must be used (sodium citrate). It is important that the sample is
transported to the immunology lab correctly.
Normal reference range: 70 - 130% Normal
Volume and sample type: 5ml sodium citrate
Method: Enzyme immunoassay
Turnaround time (calendar days from sample
receipt to authorised result): Median - 2, 95th percentile - 17
Indications for the test: Angioedema associated
with low C4 when C1-esterase inhibitor is normal or high.
Factors affecting the test: Also seen in
acquired C1-inhibitor deficiency in older patients where it is
associated with myeloma/lymphoma.
Clinical workstation reference: C1 INH FUNC
(Last updated October 7th