C3

Test Code

Alias/See Also

Complement Component 4, Complement C4

CPT Codes
86160

Preferred Specimen

Green

Minimum Volume

0.5 mL

Other Acceptable Specimens

Lithium Heparin Plasma (green top) tube

Transport Container

Serum (gold top) tube or Lithium Heparin Plasma (green top) tube

Transport Temperature

Room Temperature or Refrigeration

Specimen Stability

Room Temperature - 1 day; Refrigerated - 7 days

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

Quantity Not Sufficient, IV contamination

Methodology
Photometric

Setup Schedule

Daily upon receipt

Report Available

Upon completion of analysis

Reference Range

14 - 44 mg/dL

Clinical Significance

C4 is one of the activating enzymes of the complement system. Activation of C4 leads to formation of the C3 convertase in the classical pathway. C4 plays a contributing role in tissue cell damage and inflammation in immunologic disorders. Depressed levels of C4 due to increased consumption may be found in systemic lupus erythematosus (SLE), hereditary angioedema, autoimmune hemolytic anemia, and autoimmune nephritides. A genetic deficiency of C4 is associated with a high prevalence of autoimmune or collagen vascular disease, especially SLE. As an acute-phase reactant, modestly increased levels may occur in inflammation, trauma, and tissue necrosis.

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.