C6 Complement, Functional, Serum
Use
The C6 Complement, Functional, Serum test is crucial for diagnosing C6 deficiency and investigating patients with an undetectable total complement level. The complement system is part of the innate immune system, consisting of various pathways for activation. The primary pathway involved is the classical pathway, which is activated in the presence of immune complexes. Accurate diagnosis and measurement of C6 levels are essential as deficiencies are linked with systemic meningococcal infections and, in some cases, invasive gonococcal infections. Functional testing is recommended, as normal C6 antigen levels can occur alongside dysfunctional C6 lytic activity.
Special Instructions
Fasting for 12 hours is preferred but not required before specimen collection. Proper specimen handling is critical to ensuring that the complement system is not activated inadvertently before clinical testing. If C6 functional levels are low in the presence of normal C6 antigen levels, the test should be replicated with a new serum specimen to rule out inactivation during shipping.
Limitations
The complement proteins are prone to activation if not handled correctly; thus, careful specimen collection is necessary to ensure validity. Errors in specimen handling, such as failure to keep the sample on ice or improper centrifugation and freezing, can lead to inaccurate results. Gross hemolysis or lipemia are causes for specimen rejection, which underscores the importance of precise sample processing.
New York Approved
Methodology
Other
Biomarkers
LOINC Codes
- 60459-5
- 60459-5
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
1. Immediately after specimen collection, place the tube on wet ice. 2. Allow the specimen to clot on wet ice and then centrifuge at 4 degrees C. 3. Aliquot serum into a plastic vial. 4. Freeze specimen within 30 minutes of centrifugation. Dry ice is required if the specimen is not frozen immediately.
Patient Preparation
Fasting: 12 hours, preferred but not required
Storage Instructions
Frozen: 14 days
Causes for Rejection
Gross hemolysis, gross lipemia
Stability Requirements
| Temperature | Period |
|---|---|
| Frozen | 14 days |