Individual test · Labcorp 001834

Complement C4

This test measures the level of Complement C4, a protein that works with your immune system to fight infections and manage inflammation. It helps show if your body is using up this protein too quickly, which often happens during active inflammation or autoimmune reactions. Results can help doctors evaluate conditions like lupus or kidney disease. However, this test does not diagnose a specific disorder on its own and is usually interpreted alongside other immune system tests.