Complement 3 (C3) Level, Serum

Complement 3 (C3) Level, Serum

Complement 3 (C3) Level Test

The Complement 3 (C3) Level, Serum test measures the amount of C3 protein in the blood. C3 is an important part of the body’s immune system and plays a key role in fighting infections, inflammation, and autoimmune reactions. This test helps doctors evaluate immune system activity and diagnose conditions related to inflammation or immune disorders.

Why is this test done?

Doctors may recommend a C3 Level test to:

• Diagnose autoimmune diseases such as lupus
• Monitor immune system disorders
• Evaluate recurrent infections
• Assess kidney diseases related to immune activity
• Monitor inflammatory conditions
• Track response to treatment in autoimmune diseases

Symptoms that may require this test

• Joint pain or swelling
• Persistent fatigue
• Skin rashes
• Frequent infections
• Kidney-related symptoms such as swelling or foamy urine
• Unexplained inflammation

Sample Required

• Sample Type: Serum
• Preparation: Usually no special fasting required unless advised by your doctor

Normal Reference Range

Reference ranges may vary slightly between laboratories, but generally:

• C3: 90 – 180 mg/dL

Interpretation of Results

• Low C3 Levels may indicate:
  • Systemic Lupus Erythematosus (SLE)
  • Kidney disease
  • Severe infections
  • Autoimmune disorders
  • Liver disease
• High C3 Levels may indicate:
  • Acute inflammation
  • Certain infections
  • Chronic inflammatory conditions

Benefits of the Test

• Helps diagnose autoimmune diseases early
• Assists in monitoring disease activity
• Supports treatment planning
• Evaluates immune function effectively