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Complement C3

What Is Complement C3?

Complement C3 is a key protein in the complement system, an essential part of the immune response that helps the body defend against infections. Produced by the liver and present in the bloodstream, C3 plays a central role in activating the immune cascade that targets and eliminates pathogens.

Function of Complement C3 in the Immune System

Once activated, Complement C3 contributes to several important immune functions, including:

Opsonisation – tagging foreign particles for destruction

Recruitment of immune cells to areas of infection or injury

Formation of the membrane attack complex (MAC), which directly lyses harmful cells

These mechanisms are crucial in controlling infections and supporting immune surveillance.

What Does the Complement C3 Test Measure?

The Complement C3 blood test measures the concentration of C3 protein in the blood. This test is useful for evaluating immune function and can help detect various immune-related or inflammatory disorders.

Medical Conditions Linked to Abnormal C3 Levels

Low C3 levels are frequently seen in autoimmune diseases such as:

Systemic lupus erythematosus (SLE)

Rheumatoid arthritis

Glomerulonephritis
These lower levels may reflect active disease and increased consumption of complement proteins.

High C3 levels may indicate:

Acute infections

Chronic inflammatory conditions

Metabolic disturbances such as obesity or cardiovascular disease

Importance of Clinical Context in Test Interpretation

The results of a Complement C3 test should always be interpreted alongside other clinical findings and diagnostic results. Additional testing may be required to accurately diagnose or monitor complex immune or inflammatory disorders.

Complement C3 Testing in Slough and Surrounding Areas

Private Complement C3 blood testing is available in Slough, Windsor, Langley, Maidenhead, and nearby Berkshire areas. If you're experiencing symptoms related to autoimmune conditions or recurrent infections, local diagnostic services in Slough offer fast, reliable testing to support early detection and effective treatment planning.

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