Laboratory Test Information Guide

Details for Complement C4, Plasma

Test Name: Complement C4, Plasma
Alternate Name(s): C4
Laboratory: Core
Specimen Type: Adult:
4.5 mL Green (Lithium Heparin) top Vacutainer

Pediatric:
0-2 years: 0.5 mL Light Green top (Li-Heparin) Microtainer
2-10 years: 3 mL Light Green top (Li-Heparin) Vacutainer tube
Collection Information: Fasting specimen preferred.

Collect blood aseptically in a Vacutainer tube.

Avoid hemolysis.

Serum from a 5 mL Gold top or 6 mL Red top is also acceptable.
Requisition: GENERAL LABORATORY REQUISITION
Test Schedule: Daily
Turnaround time from when specimen
is received in testing laboratory:
 
Routine
4 hours
Stat
N/A
 
Reference Range: 0.10-0.40 g/L
Effective Date: 2009-02-27
Revised Date: 2018-03-06
Critical Value:  
Interpretive Comments: This test quantitates the amount of C4 in the plasma but does not test C4 function.
Decreased levels are associated with complement classical pathway activation, decreased or dysfunctional C1 esterase inhibitor or genetic deficiency.
Major clinical manifestations include SLE, glomerulonephritis, and pyogenic infections.
Special Processing:  
Comments: Normally run in conjunction with C3
C4 degrades in storage.
Turbidimetric assays not suitable for measurement of highly lipemic or hemolytic samples or samples containing high levels of circulating immune complexes.
Method of Analysis: Turbidimetry
Critical Information Required:  
Storage & Shipment: Specimen is stable for 2 days at 20-25C and 8 days at 4-8C.
System Codes: 
Cerner
C4
C3C4
 
Referred To:  

Questions? Comments? Contact Laura Gopaul