Complement Component C8
Test Mnemonic
COMPF8
CPT Codes
- 86161 - QTY (1)
LOINC ®
50997-6
Aliases
- (formerly Complement Functional C8)
Performing Laboratory
Mayo Clinic Dpt of Lab Med & Pathology
FDA Category
Laboratory Developed Test
Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 1 mL | Serum | No additive (Red) | Frozen | Patient should be fasting. Do not use serum separator tubes. |
Minimum Specimen Requirements
| Volume | Type | Container | Collect Temperature | Transport Temperature | Special Instructions |
|---|---|---|---|---|---|
| 0.5 mL |
Stability
| Environmental Condition | Description |
|---|---|
| Frozen | 2 weeks |
| Ambient | Unacceptable |
| Refrigerated | Unacceptable |
Days Performed
Mon - Sat
Turnaround Time
2 - 4 days
Methodology
| Name | Description |
|---|---|
| Turbidimetry (TURB) |
Reference Range
| Complement Component C8 | |||||
|---|---|---|---|---|---|
| Sex | Age From | Age To | Type | Range | Range Unit |
| Normal | 33 - 58 | U/mL |
Special Info
Patient should be fasting. Do not use serum separator tubes.
Clinical Info
Low levels of complement may be due to inherited deficiencies, acquired deficiencies, or due to complement consumption (eg, as a consequence of infectious or autoimmune processes). Absent C8 levels in the presence of normal C3 and C4 values are consistent with a C8 deficiency. Absent C8 levels in the presence of low C3 and C4 values suggests complement consumption. Normal results indicate both normal C8 protein levels and normal functional activity. Absent (or low) C8 functional levels in the presence of normal C8 antigen levels should be replicated with a new serum specimen to confirm that C8 inactivation did not occur during shipping.