This test measures the level of Complement C3, a protein involved in immune defense and inflammation.
Diagnostic Value: Low C3 levels may indicate immune complex–mediated kidney disease, such as lupus nephritis or glomerulonephritis, while elevated levels can occur with acute inflammation or infection.
Clinical Significance: Persistent reduction in C3 may signal ongoing immune activation against kidney structures, contributing to progressive renal damage.
Symptom Correlation: Patients may present with swelling, dark urine, or elevated blood pressure linked to renal inflammation.
Because it reflects immune activity within the kidneys, C3 testing helps identify and monitor autoimmune or inflammatory renal disorders.