Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
C1 esterase inhibitor is an enzyme which controls activation of the classical complement pathway along with inhibition of enzymes in the blood clotting pathway. Genetic deficiencies exist which cause Hereditary Angioedema (HAE). The majority of patients have low levels of C1 esterase inhibitor, with around 20% of patients having normal levels of a non functional inhibitor.
Specimen container paediatric:
Serum-Plain tube
Specimen container adult:
Serum-SST
Minimum volume paediatric:
1 ml
Minimum volume adult:
1 ml
Special requirements:
Samples MUST be separated within 4 hours of venesection. Please ensure that the sample arrives in the laboratory as soon as possible after being taken.
Freq analysis:
Fortnightly
Add on test:
Cannot be added on without discussion with Proteins Laboratory
Quality assurance:
UK NEQAS for C1 Inhibitor and Functional Complement INSTAND Complement EQA scheme
Interpretation:
Low levels are associated with Type I HAE. Normal C1 esterase levels does not rule out HAE and so C1 functional testing is carried out to rule out a problem with enzyme function.
Reference ranges:
Normal Adult Range: >0.18 mg/L
Other info:
Reported as a numerical value