Complement C1q (C1q) Antibodies, Serum

Complement C1q (C1q) Antibodies, Serum

Test Overview

The Complement C1q (C1q) Antibodies, Serum test detects IgG autoantibodies directed against the C1q component of the complement system, an important part of the body's immune defense mechanism. Anti-C1q antibodies are associated with certain autoimmune and inflammatory disorders, particularly lupus-related kidney disease.

Why is this Test Ordered?

This test may be recommended for:

• Evaluation of Systemic Lupus Erythematosus (SLE)
• Assessment of Lupus Nephritis (kidney involvement in lupus)
• Investigation of Hypocomplementemic Urticarial Vasculitis Syndrome (HUVS)
• Monitoring disease activity in autoimmune disorders
• Evaluation of unexplained low complement levels

Specimen Required

• Sample Type: Serum
• Container: Plain Red Top / Serum Separator Tube (SST)
• Patient Preparation: No special preparation required

Clinical Significance

Anti-C1q antibodies bind to the C1q protein and can activate the classical complement pathway, leading to inflammation and tissue damage. Elevated levels are commonly associated with:

• Systemic Lupus Erythematosus (SLE)
• Active Lupus Nephritis
• Hypocomplementemic Urticarial Vasculitis
• Certain infectious conditions such as HIV and Hepatitis C infections

Interpretation of Results

A positive result supports the presence of anti-C1q antibodies but should always be interpreted along with clinical findings and other laboratory tests such as C3 and C4 complement levels.

Symptoms That May Prompt Testing

• Persistent rash or hives
• Joint pain and swelling
• Kidney disease symptoms
• Blood in urine
• Unexplained inflammation
• Suspected autoimmune disease

Reporting Time

Approximately 3–7 working days (may vary by laboratory).

SEO Meta Description

Complement C1q (C1q) Antibodies, Serum test measures autoantibodies against C1q to aid in the diagnosis and monitoring of lupus nephritis, systemic lupus erythematosus (SLE), and hypocomplementemic urticarial vasculitis. #Dermafact #gynofact