Oct 24, 2024 · A C4 complement blood test measures the levels of a certain protein in your blood. The test tells your healthcare provider how well your immune system is working.

Feb 25, 2024 · A complement C4 (also known as a complement component 4, or simply C4) is a test to measure the level of C4 proteins you have in your blood.

The normal range for a complement C4 blood test is 16 to 48 milligrams per deciliter (mg/dL), or 0.16 to 0.48 grams per liter (g/L). Your complement levels will often shoot up dramatically just after an infection or injury.

Jan 7, 2021 · Complement C4 plays an important role in eliminating certain infections. The complement component 4 (C4) test is a simple blood test that measures the amount of complement C4 circulating in...

Dec 15, 2022 · Normal complement C4 levels in the blood are between 16 and 47 mg/dL (milligrams per deciliter), or 0.16 to 0.47 g/L (grams per liter). Levels may vary slightly between laboratories. Your healthcare provider will recommend …

Jul 6, 2021 · WHAT DOES IT MEAN IF YOUR COMPLEMENT C4A RESULT IS TOO LOW? Lower-than-normal complement C4 values could indicate: – bacterial infections. – hepatitis. – malnutrition. – rejection of a kidney transplant. – systemic lupus erythematosus, which is an autoimmune disease affecting the skin, joints, kidneys, and other organs.

What Is the Complement System? The C4 complement blood test helps medical providers take a look at a person’s immune system. The complement system helps the immune system eliminate pathogens that may have invaded the body. C4 levels are just one of the complement measures that are looked at.

Jul 3, 2019 · Complement C4 test result greater than the upper limit (more than 48 mg/dl) mentioned in the reference range is considered to be abnormal. Low complement C4 levels are often seen in autoimmune disorders or when there is an interference with C4 complement production such as liver diseases.

Abnormal levels of C4 can help identify conditions such as lupus, rheumatoid arthritis, and certain kidney disorders. Understanding the test results is essential for accurate diagnosis: Normal levels: Suggest a healthy immune system with no significant abnormalities.

Feb 4, 2025 · Doctors use the C4 complement blood test to measure C4 protein levels in the blood. Since C4 plays a key role in immunity, its assessment remains essential. This test evaluates complement system activity. Because C4 helps regulate immune responses, abnormal levels suggest immune dysfunction.