Compare this test’s laboratory options
Complement C4
Quest Diagnostics1 test optionFrom $30.62
Complement C4
Quest DiagnosticsCatalog information reviewed: August 24, 2026 by the Sunridge Medical clinical team.
What this laboratory test evaluates
DetailsComplement Component C4c – Decreased C4 level is associated with acute systemic lupus erythematosis, glomerulonephritis, immune complex disease, cryoglobulinemia, congenital C4 deficiency and generalized autoimmune disease.
What type of sample is required for this test?1 mL serum
Test ResourcesFor more information, please consult your healthcare provider.
Additional test information
Complement Component C4c – Decreased C4 level is associated with acute systemic lupus erythematosis, glomerulonephritis, immune complex disease, cryoglobulinemia, congenital C4 deficiency and generalized autoimmune disease.
Collection and processing
- Sample type: Serum
- Fasting: No
- Estimated laboratory processing: Results should be available in 2 – 5 business days after the sample is collected
How Sunridge uses laboratory information
Sunridge considers the medical question, symptoms, history, medications, prior results, and whether the finding could change care before recommending testing. A laboratory result is not interpreted in isolation and does not establish a diagnosis by itself.
Before requesting this test
Availability, collection requirements, eligibility, and processing estimates can change. Sunridge reviews each request and, when appropriate, creates the order through Fullscript. Follow the current instructions supplied with the approved order.
Common questions about this laboratory test
- What sample does this test require?
- The listed sample type is Serum. Confirm current collection instructions in the approved order.
- Does this test require fasting?
- The current catalog record lists fasting as: No. Follow the instructions supplied with the approved order.
- How long does laboratory processing usually take?
- Results should be available in 2 – 5 business days after the sample is collected. Timing can change after collection or if a laboratory requires additional review.
About this test
DetailsComplement Component C4c - Decreased C4 level is associated with acute systemic lupus erythematosis, glomerulonephritis, immune complex disease, cryoglobulinemia, congenital C4 deficiency and generalized autoimmune disease.
What type of sample is required for this test?1 mL serum
Test ResourcesFor more information, please consult your healthcare provider.
Additional details
Complement Component C4c - Decreased C4 level is associated with acute systemic lupus erythematosis, glomerulonephritis, immune complex disease, cryoglobulinemia, congenital C4 deficiency and generalized autoimmune disease.
Highlighted health areas
- Immune System
Biomarkers and report focus
The exact analytes and report format can change. Confirm the current contents in the Fullscript order before payment.
- Complement Component C4c