Complement C4, Serum
Use
The Complement C4 test is useful for investigating undetectable total complement, confirming hereditary angioedema, and assessing disease activity in conditions like systemic lupus erythematosus, proliferative glomerulonephritis, rheumatoid arthritis, and autoimmune hemolytic anemia. C4 is a protein involved in the activation of the classic complement pathway and plays a crucial role in the immune defense mechanism against infections. The levels of C4 can indicate various health conditions, marked by decreased or increased levels, reflecting underlying autoimmune disorders or congenital deficiencies.
Special Instructions
When ordering this test not electronically, a Kidney Transplant Test Request form or Renal Diagnostics Test Request form must accompany the specimen. Proper specimen transport is crucial for accurate results. The testing is performed Monday through Friday, and a plastic vial should be used to submit the serum.
Limitations
Results may be affected by improper specimen collection and handling. The nephelometry method used may not be possible in lipemic sera due to light scattering properties, which may result in variable analysis. Turbidity and particles in the specimen can also lead to extraneous light scattering signals.
FDA ApprovedNew York Approved
Methodology
Immunoassay (Nephelometry)
Biomarkers
LOINC Codes
- 4498-2
- 4498-2
Result Turnaround Time
1-3 days
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.5 mL
Container
Plastic vial
Collection Instructions
Centrifuge and aliquot serum into a plastic vial.
Causes for Rejection
Gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 hours |
| Refrigerated | 7 days |
| Frozen | 28 days |