What is the Complement C2 Test?

The Complement C2 Test measures the concentration of Complement Component 2 (C2), a protein involved in the body’s immune defense. C2 plays a key role in activating the classical complement pathway, which helps destroy bacteria, viruses, and immune complexes. Low C2 levels may be associated with inherited complement deficiencies, autoimmune diseases such as Systemic Lupus Erythematosus (SLE), or recurrent bacterial infections.

Who should take this test?

• Individuals with recurrent bacterial infections.
• Patients suspected of having complement deficiency disorders.
• Individuals being evaluated for Systemic Lupus Erythematosus (SLE) or other autoimmune diseases.
• Patients with unexplained immune system disorders.
• Individuals with a family history of inherited complement deficiencies.
• Doctor-recommended investigation of immune function abnormalities.

Preparation & Test Process

Understanding Your Results

Low Complement C2 levels may indicate inherited C2 deficiency, autoimmune disorders, or increased complement consumption during active immune disease.

Normal Complement C2 levels generally suggest normal activity of the classical complement pathway, although additional testing may still be required depending on clinical symptoms.

Results should always be interpreted together with clinical findings, other complement tests, autoimmune markers, and your medical history.

FAQs – Complement C2 Test