What is a C3 complement blood test?
A C3 complement blood test measures the levels of a specific type of protein in your blood (C3 proteins). As part of your immune system, C3 proteins destroy microbes (germs) that can make you sick. Sometimes, C3 proteins launch an attack against healthy cells by mistake.
The results of this blood test give your healthcare provider information about how your immune system is working. By measuring the amount of C3 proteins, your healthcare provider can diagnose infection, disease, immune deficiency and other health conditions, like autoimmune disorders. This test also helps your healthcare provider monitor treatment for autoimmune disease.
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What is the complement system?
C3 proteins are part of the complement system, which is part of your immune system. The complement system includes more than 30 different proteins. They work together in a sequence to protect you from infection and illness.
When your immune system identifies a harmful substance or recognizes signs of an infection, it activates a protein in the complement system to launch an attack. That protein activates another protein, which activates another and another. Healthcare providers call this process a complement cascade. The proteins, like C3, are consumed in this process.
Proteins in the complement system have many jobs, including:
- Helping your immune system create antibodies (proteins that respond to specific germs) and making antibodies more effective.
- Helping your body get rid of dead cells and other waste.
- Neutralizing viruses (making them less harmful).
- Recognizing and killing viruses, bacteria and other germs.
- Working with other parts of the immune system to help them destroy bacteria.
Sometimes, complement proteins like C3 mistakenly attack tissues that aren’t dangerous. Autoimmune disorders cause the body to believe its own tissues are foreign and harmful. The complement system responds by making antibodies to fight its own tissues.
When is a C3 complement blood test performed?
Your healthcare provider may order this test if you have:
- Bacterial infections that don’t go away or keep coming back.
- Edema (swelling) or inflammation.
- Symptoms of an autoimmune disorder, like lupus.
Your healthcare provider might also recommend a C3 complement blood test to monitor:
FAQs
Summary. A C3 complement test is used to measure a protein called C3 which is part of the body's immune response. High or low values may indicate medical problems ranging from autoimmune diseases and immune disorders to infections and chronic kidney or liver disease.
What is C3 complement test results? ›
The normal range for a complement C3 blood test is 75 to 175 milligrams per deciliter (mg/dL), or 0.75 to 1.75 grams per liter (g/L). Your complement levels will often rise very high just after an infection or injury. When your complement system responds to ongoing disease such as lupus, levels usually go down.
What diseases cause low C3? ›
Decreased complement activity may be seen in:
- Bacterial infections (especially Neisseria)
- Cirrhosis.
- Glomerulonephritis.
- Hepatitis.
- Hereditary angioedema.
- Kidney transplant rejection.
- Lupus nephritis.
- Malnutrition.
Complement component 3, often called C3, is an essential protein of the immune system. This protein plays a vital role in the body's innate immune system, providing: the first line of defense against diseases. The complement C3 blood test measures the activity of this protein in your blood.
What causes C3 to be high? ›
What do high levels of C3 mean? Higher-than-normal levels of C3 proteins can indicate that you've just had an infection and your immune system is responding to it. If you're getting treatment for lupus or another autoimmune disease, higher levels of C3 proteins usually mean that treatment is working.
What is C3 deficiency disease? ›
Disease definition
Complement component 3 deficiency is a rare, genetic, primary immunodeficiency characterized by susceptibility to infection (mainly by gram negative bacteria) due to extremely low C3 plasma levels.
Why is C3 important in the complement system? ›
Complement component C3 plays a particularly versatile role in this process by keeping the cascade alert, acting as a point of convergence of activation pathways, fueling the amplification of the complement response, exerting direct effector functions, and helping to coordinate downstream immune responses.
What infections are caused by C3 deficiency? ›
Inherited C3 deficiency results in repeated, severe infections starting from birth, especially those of the respiratory tract. Organisms such as Streptococcus pneumoniae and Hemophilus influenzae are the most frequent causes of infection.
Is C3 an inflammatory marker? ›
Serum C3 Is a Stronger Inflammatory Marker of Insulin Resistance Than C-Reactive Protein, Leukocyte Count, and Erythrocyte Sedimentation Rate: Comparison study in an elderly population.
How do you treat complement deficiency? ›
Treatment depends on the type of complement deficiency. C1 inhibitor deficiencies may be treated by a range of different medications, including C1 inhibitor replacement, Lanadelumab; tranexamic acid; hormones; and drugs such as icatibant that block the action of bradykinin.
Chlorpromazine Hydrochloride Strength 50 mg Imprint C3 Color Yellow Shape Round View details.
What is the blood test for inflammation? ›
What is the C-reactive protein (CRP) blood test? The C-reactive protein (CRP) test is a blood test that checks for inflammation in your body. CRP is a protein that is made in your liver and released into your bloodstream. Levels of CRP start to increase very soon after any inflammation or infection affects your body.
What is the blood test for lupus? ›
98% of all people with systemic lupus have a positive ANA test, making it the most sensitive diagnostic test for confirming diagnosis of the disease. The test for anti-nuclear antibodies is called the immunofluorescent antinuclear antibody test. In this test, a blood sample is drawn and sent to a laboratory.
What is a normal C3 blood level? ›
Understanding the test results of the complement C3 Test
88 to 201 milligrams per deciliter (mg/dL) or 0.88 to 2.01 grams per litre is considered the normal range.
What is C3 disease? ›
The C3 glomerulopathies are a group of rare kidney diseases characterized by complement dysregulation occurring in the fluid phase and in the glomerular microenvironment, which results in prominent complement C3 deposition in kidney biopsy samples.
Does C3 trigger inflammation? ›
C3a is an anaphylatoxin that modulates the production of inflammatory factors such as IL-1 and stimulates respiratory burst such as macrophages and the chemotaxis of mast cells [18,19].
What is complement C3 kidney disease? ›
In C3 glomerulopathy, the complement system becomes overactive or doesn't work as it should. The overactive complement system leads to damage and inflammation of the glomeruli (which help the kidneys filter toxins out of your blood).
What does normal C3 and low C4 mean? ›
Answer: The low C4 and normal C3 would suggest additional diagnoses of SLE, mixed cryoglobulinemia, and membranoproliferative glomerulonephritis. If the cryoglobulins are positive, then could consider hepatitis B and C.
What do complement levels indicate? ›
If your results show increased levels or activity of complement proteins, it may mean that your body has acute or chronic inflammation. Increased levels may be a sign of the following conditions: Certain types of cancer, such as leukemia or non-Hodgkin lymphoma.
