COMPLEMENT, C4

Message

NOTE: Clotting process requires a total of 30-60 minutes.

Prior to centrifugation, allow sample to clot at room temperature for 15-30 minutes.
Refrigerate sample, allow clotting to continue for a full 30 minutes.
Rim the clot then centrifuge in a refrigerated centrifuge. If a refrigerated centrifuge is not available, aliquot serum and refrigerate immediately.
If sample will not be tested within 4 hours of centrifugation, refrigerate or freeze serum, not the red tube.

Test Code

CPT Codes
86160

Preferred Specimen

1 Red tube

Minimum Volume

0.3 mL

Other Acceptable Specimens

1 Gold tube (SST)

Instructions

NOTE: Clotting process requires a total of 30-60 minutes.

Prior to centrifugation, allow sample to clot at room temperature for 15-30 minutes.
Refrigerate sample, allow clotting to continue for a full 30 minutes.
Rim the clot then centrifuge in a refrigerated centrifuge. If a refrigerated centrifuge is not available, aliquot serum and refrigerate immediately.
If sample will not be tested within 4 hours of centrifugation, refrigerate or freeze serum, not the red tube.

Transport Temperature

Refrigerate

Specimen Stability

2-8°C up to 8 days
15-30°C up to 4 hours
Frozen up to 8 days (thaw only once)

Reject Criteria (Eg, hemolysis? Lipemia? Thaw/Other?)

Hemolyzed

Methodology

Immunoturbidemetric

Setup Schedule

As received, STAT testing is available

Report Available

Within 24 hours of receipt at the performing laboratory.

Reference Range

19 - 52 mg/dL

Clinical Significance

The Complement system is composed of a series of circulating blood proteins that serve as mediators of the inflammatory response. C4 is utilized only by the classical complement pathway, so that it is decreased only when this pathway is activated. In diseases activating the alternate pathway alone, C4 levels will be normal. Measurements of this protein aids in the diagnosis of immunologic disorders, especially those associated with
deficiencies of complement components.

Performed By
Alverno Laboratories

Performing Laboratory
Alverno Central Lab
NCHB1 (Chemistry, Beckman AU)

Last Updated: June 7, 2023

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.