Complement Components 3 and 4
Also known as: C3C4
Use
This test is used to monitor rheumatologic diseases, including systemic lupus erythematosus (SLE) and IgG4-related disease. It evaluates the levels of complement components C3 and C4, which are significant for assessing disease activity. Low levels of these components may indicate consumption of complement proteins in the circulation or in tissues, and this can be associated with certain autoimmune diseases.
Special Instructions
Allow collected specimens to clot at room temperature and separate serum from cells as soon as possible, or within two hours of collection. Transfer 1 mL serum to an ARUP Standard Transport Tube and freeze. Avoid repeated freeze/thaw cycles for specimen stability. Specimens must not be left to clot at refrigerated temperatures.
Limitations
The test is limited by its inability to fully diagnose specific diseases without correlation with clinical findings and other laboratory tests. This test does not specify which diseases are causing decreased complement levels, and nonspecific inflammatory responses can also alter complement levels.
New York Approved
Methodology
Immunoassay (Quantitative Immunoturbidimetry)
Biomarkers
LOINC Codes
- 4485-9
- 4498-2
- 4485-9
- 4498-2
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Serum
Volume
1 mL
Minimum Volume
0.6 mL
Container
ARUP Standard Transport Tube
Collection Instructions
Allow specimen to clot at room temperature. Separate serum from cells ASAP or within 2 hours of collection.
Causes for Rejection
Specimens left to clot at refrigerated temperature. Specimens exposed to repeated freeze/thaw cycles.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 48 hours |
| Refrigerated | 8 days |
| Frozen | 2 weeks (avoid repeated freeze/thaw cycles) |