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HelpTest Code LAB8814 Complement C1q, Serum
Additional Codes
C1Q
Useful For
Assessment of an undetectable total complement (CH50) level
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Diagnosing congenital C1 (first component of complement) deficiency
Diagnosing acquired deficiency of C1 inhibitor
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
SerumSpecimen Required
Patient Preparation: Fasting for 12 hours
Container/Tube:
Preferred: Red top
Acceptable: Serum gel
Submission Container/Tube: Plastic vial
Specimen Volume: 1 mL
Collection Instructions: Centrifuge and aliquot serum into plastic vial
Specimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum | Refrigerated (preferred) | 28 days | |
| Frozen | 28 days | ||
| Ambient | 21 days |
Reference Values
12-22 mg/dL
Day(s) Performed
Monday through Friday
CPT Code Information
86160
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| C1Q | Complement C1q, S | 4478-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| C1Q | Complement C1q, S | 4478-4 |
Interpretation
An undetectable C1q in the presence of an absent total complement (CH50) and normal C2, C3, and C4 suggests a congenital C1 (first component of complement) deficiency.
A low C1q in combination with a low C1 inhibitor and low C4 suggests an acquired C1 inhibitor deficiency.
Method Description
Nephelometry and anti- C1q antiserum are used to quantitate the C1q antigen level.(Instruction manual: Siemens Nephelometer II. Siemens, Inc; Version 2.3, 2008; Addendum to the Instruction Manual 2.3, 08/2017)
Report Available
2 to 5 daysSpecimen Retention Time
14 daysReject Due To
| Gross hemolysis | OK |
| Gross lipemia | Reject |
| Gross icterus | OK |
Method Name
Nephelometry