Immune System

Complement C4, Serum

Optimal Result: 14 - 44 mg/dL.

What is Complement component 4 (C4):

Complement component 4 (C4) is a blood test that measures the activity of a certain protein. This protein is part of the complement system.

What is the complement system?

The complement system is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promotes inflammation, and attacks the pathogen’s cell membrane.

Complement may also be activated during reactions against incompatible blood transfusions, and during the damaging immune responses that accompany autoimmune disease. Deficiencies of individual complement components or inhibitors of the system can lead to a variety of diseases.

There are nine major complement proteins. They are labeled C1 through C9.

C3 and C4 are the most commonly measured complement components. When the complement system is turned on during inflammation, levels of complement proteins may go down. Complement activity may be measured to determine how severe a disease is or if treatment is working.

What is a complement test being used for?

A complement test may be used to monitor people with an autoimmune disorder. For example, people with active systemic lupus erythematosusmay have lower-than-normal levels of the complement proteins C3 and C4.

Complement activity varies throughout the body. In people with rheumatoid arthritis, complement activity may be normal or higher-than-normal in the blood, but much lower-than-normal in the joint fluid.

More details on C4:

C4 is the most second-most abundant of the 11 complement proteins (after C3). It is also among the best studied. Levels of C4 are known to increase during inflammation and tissue destruction, and decrease during autoimmune disorders. The Complement C4 Blood Test helps determine the levels of C4 in blood. It is used to determine if deficiencies in the complement system are contributing to an immune disorder.

References:

 

What does it mean if your Complement C4, Serum result is too low?

Lower-than-normal complement C4 values could indicate:

- bacterial infections (especially Neisseria)

- hepatitis

- malnutrition

- rejection of a kidney transplant

- systemic lupus erythematosus, which is an autoimmune disease affecting the skin, joints, kidneys, and other organs

- lupus nephritis, which is a kidney disorder that often occurs as a result of systemic lupus erythematosus

- cirrhosis, which indicates significant liver damage

- glomerulonephritis, which is a type of kidney disease

- hereditary angioedema, which is a rare but serious autoimmune disease that causes swelling in various parts of the body

Complement component activity varies throughout the body. People with rheumatoid arthritis, for example, may have high complement levels in their blood but low complement levels in their joint fluid.

What does it mean if your Complement C4, Serum result is too high?

Higher-than-normal complement C4 values may be a sign of cancer or ulcerative colitis.

10 000+ happy clients
100% satisfaction
★ ★ ★ ★ ★ customer support

Understand blood, stool, and urine medical results from all your laboratories.

Get Started With Our Personal Plan

Advanced Plan

  • ✓ Yearly subscription
  • ✓ Five free uploads
  • ✓ Cancel anytime
  • ✓ Instant interpretations
  • ✓ Use the free self-upload form
  • ✓ 3000+ biomarkers explained
  • ✓ Nutrition Recommendations
  • ✓ Dedicated support
  • ✓ Yearly subscription
  • ✓ Five free uploads
  • ✓ Cancel anytime
$79 per year
  • ✓ Instant interpretations
  • ✓ Use the free self-upload form
  • ✓ 3000+ biomarkers explained
  • ✓ Nutrition Recommendations
  • ✓ Dedicated support

Unlimited Plan

  • ✓ No subscription
  • ✓ Ten free uploads
  • ✓ Unlimited access
  • ✓ Instant interpretations
  • ✓ Use the free self-upload form
  • ✓ 3000+ biomarkers explained
  • ✓ Nutrition Recommendations
  • ✓ Dedicated support
  • ✓ No subscription
  • ✓ Ten free uploads
  • ✓ Unlimited access
$250 full version

Are You a Health Professional?

Get started with our professional plan

Welcome to Healthmatters Pro.

Save time on interpreting lab results with the largest database of biomarkers online. In-depth research on any test at your fingertips, all stored and tracked in one place. Learn more

Pro Plan

for health professionals

  • ✓ Track multiple clients results
  • ✓ No setup fees
  • ✓ No hidden costs
  • ✓ Cancel anytime
  • ✓ Instant interpretations
  • ✓ Use the free template forms
  • ✓ 3000+ biomarkers explained
  • ✓ Additional team member $25
  • ✓ Personal training and support

$45 per month

Use promo code to save 10% off any plan.


We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

×

Understand Your Lab Result Now

  • Instant interpretation
  • 3000+ biomarkers explained
  • Science-based recommendations
  • Online support
  • Secure and private portal

Get 10% off with promocode: