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HelpOrder Code C341Q Complement C3 and C4 with Anti-C1q Antibodies, Serum
Specimen Required
Supplies: Sarstedt Aliquot Tube, 5 mL (T914)
Collection Container/Tube:
Preferred: Serum gel
Acceptable: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 1.5 mL
Collection Instructions: Centrifuge and aliquot serum into a plastic vial
Useful For
Evaluating patients with suspected anti-C1q vasculitis
Predicting renal involvement in patients with systemic lupus erythematosus
Profile Information
| Test ID | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| C3 | Complement C3, S | Yes | Yes |
| C4 | Complement C4, S | Yes | Yes |
| AC1Q | Anti-C1q Antibodies, IgG, S | Yes | Yes |
Method Name
AC1Q: Enzyme-Linked Immunosorbent Assay (ELISA)
C3, C4: Nephelometry
Reporting Name
C3 and C4 with Anti-C1q, IgG, SSpecimen Type
SerumSpecimen Minimum Volume
0.9 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum | Refrigerated (preferred) | 7 days |
| Frozen | 21 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | Reject |
| Gross icterus | Reject |
Reference Values
C3:
75-175 mg/dL
C4:
14-40 mg/dL
AC1Q:
<20 U/mL (Negative)
20-39 U/mL (Weak Positive)
40-80 U/mL (Moderate Positive)
>80 U/mL (Strong Positive)
Method Description
C3:
C3 is measured by immunonephelometry. Antiserum to C3 is mixed with patient serum, the light scatter resulting from the antibody interaction with C3 is measured, and the signal is compared to standard concentrations of C3.(Instruction manual: Siemens Nephelometer II Operations. Siemens, Inc; Version 2.4, 07/2019; Addendum to the Instruction Manual 2.3, 08/2017)
C4:
C4 is measured by immunonephelometry. Antiserum to C4 is mixed with patient serum, the light scatter resulting from the antibody interaction with C4 is measured, and the signal is compared to standard concentrations of C4.(Instruction manual: Siemens Nephelometer II Operations. Siemens, Inc; Version 2.4, 07/2019; Addendum to the Instruction Manual 2.3, 08/2017)
Anti-C1q antibodies, IgG:
Testing for antibodies to C1q is accomplished using a laboratory-developed immunoassay.(Unpublished Mayo method)
Day(s) Performed
C3, C4: Monday through Friday
AC1Q: Wednesday
Performing Laboratory
Mayo Clinic Laboratories in Rochester
CPT Code Information
86160 x2
83520