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Dr. Shreya Gupta

BDS, MDS - Oral and Maxillofacial Pathology

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Complement 4

Also known as Complement component 4, C4 Complement Blood Test

₹629~~₹800~~ 21% Off

You need to provide

Blood

This test is for

Male, Female

Test Preparation

Overnight fasting is preferred but not mandatory.

Understanding Complement 4

What is Complement 4?

The Complement 4 test is a blood test that assesses levels of complement component 4 (C4), a protein involved in the immune system's complement cascade. This test helps detect autoimmune diseases, infections, and other conditions with dysfunction in the immune system.

Complement component 4 (C4) is a protein in the blood that plays a crucial role in the complement system, which is part of the immune system. It helps fight infections by inducing the destruction of pathogens and damaged cells.It plays an important role in the immune system, facilitating immune reactions such as inflammation.

The activity of the complement system may be altered (can become overactive or underactive) in various autoimmune diseases like systemic lupus erythematosus (SLE) or rheumatoid arthritis, which leads to abnormal inflammation or underreactive immune responses.

The Complement 4 test is especially helpful in identifying and monitoring autoimmune disorders, where changes in C4 levels are indicative of disease flare-ups or remission phases. Doctors may also advise the Complement 4 test to individuals who have unexplained symptoms of autoimmune or inflammatory conditions, such as joint pain, renal issues, skin rashes, recurrent infections, or if there is a family history of autoimmune diseases. It is also used to assess disease activity and effectiveness of treatment in patients with SLE or other conditions that involve complement system dysregulation.

High or low C4 levels can indicate different health conditions. Low C4 levels are often associated with autoimmune diseases such as lupus, conditions that represent an overactive and depleted complement system. It may also be seen in conditions like glomerulonephritis and inflammation due to kidney infections. High C4 concentrations are less common but can be associated with acute inflammation, certain infections, or conditions like rheumatoid arthritis. C4 levels, therefore, can vary with the severity of the disease and its stage.

Although fasting for 8 to 12 hours before blood sample collection is preferred, but is not absolutely essential. Remember to inform the doctor about all the medications or supplements being taken, and tell the complete medical history, including existing health conditions, to rule out any influence of these factors on test results.

Lab test results may vary across laboratories due to differences in methodologies and reference ranges. Abnormal test results require expert interpretation. Do not self-medicate based solely on the results. Always consult a doctor to understand the test results correctly.

What is Complement 4 used for?

The Complement 4 test is done:

To assist in diagnosing autoimmune diseases such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), vasculitis, etc.
To find the cause of unexplained symptoms such as joint pain, swelling, skin rashes, and fatigue, which might suggest autoimmune or inflammatory diseases.
To monitor the functioning of the immune system, especially in chronic infections or inflammation.
To assess disease progression or remission in patients with autoimmune disease.
To check for renal involvement of lupus nephritis or other autoimmune disorders.
To check whether either an infection or inflammation is lowering complement protein levels.
To investigate any family history of complement deficiencies or autoimmune diseases.

What does Complement 4 measure?

The Complement 4 test measures the complement protein C4 level in the blood, which is an important part of the immune system. C4 has an important role in the complement system that fights infections, triggers inflammation, and clears out damaged cells. By determining C4 levels in the blood, this test offers crucial insights into the activity and functionality of the complement system. Abnormal (lower or higher than healthy range) results may point toward autoimmune conditions, inflammatory diseases, or infections, helping doctors diagnose and monitor various health issues related to the immune system.

Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Complement 4

Frequently Asked Questions about Complement 4

Q. What is the Complement 4 test?

The Complement 4 test is a blood test for determining the levels of C4, a protein found in the complement cascade of the immune system. It helps in the diagnosis of various autoimmune diseases, infections, or some immune deficiencies.

Q. Why would my doctor recommend the Complement 4 test?

Your doctor may recommend the Complement 4 test to aid in diagnosing autoimmune diseases such as lupus or rheumatoid arthritis and to track the progression of these diseases, to identify significant inflammation or infection in the body, or to evaluate the functioning of your immune system, especially if there are unexplained symptoms such as joint pain, fatigue, or skin rashes.

Q. Do I need to fast before undertaking the Complement 4 test?

Fasting for 8 to 12 hours before the test is preferred but not mandatory. However, it is advised to follow your doctor’s instructions closely to ensure accurate results.

Q. How is the Complement 4 test performed?

A phlebotomist (a trained professional to perform blood draws) will clean your skin using an antiseptic alcohol cotton swab or wipe and take blood samples from your vein using a needle. The blood sample will be stored safely and transported to the laboratory for analysis.

Q. Is the Complement 4 test safe?

Yes, the Complement 4 test is generally safe with minimal risks. However, you may feel slight discomfort during blood sample collection, but chances of serious complications are extremely rare.

Q. What do the results of the Complement 4 test mean?

Low levels of C4 can indicate autoimmune diseases, such as lupus or other inflammatory conditions. High levels may suggest an acute inflammatory response or infection. The results should be interpreted by your doctor, who will consider other factors and tests to determine the cause of any abnormalities.

Q. Are the tests of complement 3 (C3) and Complement 4 (C4) different?

Yes, while the C3 and Complement 4 tests measure complement proteins. The complement 3 test measures the levels of C3, which is involved in both the recognition of pathogens and the inflammatory process. C4 is involved in the early activation of the immune system. Both tests can be useful in diagnosing autoimmune conditions but may be used for different aspects of the immune system.

Q. How often should I get tested for the Complement 4 test?

The frequency of testing is based on different factors such as one's medical history, any clinical symptoms, and the doctor’s recommendation. Your doctor will guide you best on how frequently you should get the Complement 4 test done.

Q. What other tests might I have along with this test?

Complement 4 is frequently taken together with Complement 3 (C3), another protein in the complement system, to help with diagnosing and evaluating conditions such as systemic lupus erythematosus (SLE). Other associated tests include kidney function tests, autoantibody tests, and markers of inflammation to assess the overall functioning of the immune system.

Q. What other complement proteins are there besides C4?

The complement system comprises several proteins involved in immune defense, including C4, C1, C2, C3, C5, C6, C7, C8, and C9.

Q. What is the complement system?

The complement system is a part of the immune system made up of a group of proteins that work together to defend the body against infections, remove dead cells, and promote inflammation. It plays a key role in identifying and attacking pathogens, like bacteria, viruses, and fungi, and helps in the body's overall immune response.

Q. How does Tata 1mg ensure accurate lab test results?

Tata 1mg ensures accurate lab test results through certified laboratories that use advanced technology and adhere to stringent quality control measures. This commitment to high standards guarantees reliable results.

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