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Test Code Billings Clinic: 4090 C4 (Fourth Component of Complement), Serum

Performing Laboratory

Billings Clinic Laboratory: Chemistry

Useful For

  • Investigating an undetectable total complement (CH50)
  • Confirming hereditary angioedema (with low C1 inhibitor)
  • Assessing disease activity in systemic lupus erythematosus, proliferative glomerulonephritis, rheumatoid arthritis, and autoimmune hemolytic anemia

Methodology

Immunoturbidimetric

Specimen Requirements

Serum should be physically separated from cells as soon as possible with a maximum limit of two hours from the time of collection.

 

Serum

  • Draw blood in a plain, red-top tube(s) or a serum gel tube(s).
  • Spin down and send 1.0 mL of serum frozen

Storage/Stability

Specimen Type Temperature Time
Serum Refrigerated 7 days
  Frozen (preferred) 3 months

 

Reject Due To

  • Specimens received outside of the required storage and stability requirements

Reference Values

10.0 - 40.0 mg/dL

Day(s) Test Set Up

Daily

Test Classification and CPT Coding

86160 - Complement; antigen, each component

LOINC Code Information

Reporting Name LOINC Code
Comp, C4 4498-2