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:
Measurement of C4 is useful in the diagnosis of suspected SLE, complement deficiency and HAE. Low C4 may indicate a genetic deficiency, active SLE, the presence of a cryoglobin or active HAE. Low levels of both C3 and C4 may indicate complement consumption such as in SLE or Sepsis. However, as they are acute phase proteins their levels may be normal in times of rapid consumption.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
1 mL blood
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated sample:
24 hours
Separated sample:
2 days at 15 to 25°C,
8 days at 2 to 8°C,
3 months at -20°C
Add on test:
All urgent add ons via telephone on 0191 282 4766, and must be confirmed via email to the appropriate email address. [email protected]
Quality assurance:
INSTAND Compliment Analysis, UKNEQAS C1 Inhibitor and Functional Complement
Reference ranges:
Paediatric: Approx. 60% adult level at birth, rising to adult level at about 6m.
Adult: 0.18 – 0.60 g/L
Other info:
Lithium heparin plasma samples also acceptable