Oct 24, 2024 · Information about your C4 levels can tell your healthcare provider how well your immune system is working. Low C4 levels mean you have a higher risk of developing an autoimmune …

A low serum C4 level in patients with autoimmune disease may be due to ongoing disease activity associated with the consumption caused by complement activation and or it may be due to genetic …

If only your C4 complement level is low, and all other complement components are normal, it is usually because of an inherited component deficiency. More often, you will have lowered levels of several …

If the blood sample is mishandled, your C4 levels may be falsely low. If the C4 test is done as part of a total complement activity test, the test should be repeated if low levels are found.

Low complement levels, particularly C4, may be observed in severe or systemic forms of Sjögren’s syndrome. Complement testing helps identify patients at higher risk of complications, such as …

Feb 25, 2024 · If you have lupus, your doctor might order a C4 test to see how well your body is responding to treatment. People with lupus will have low levels of complement C4 protein during flare …

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...

If the test shows that your complement protein levels are not normal or that the proteins aren't working with the immune system as well as they should, it can be a sign of an autoimmune disease or other …

Individuals with a complement deficiency, including people with hereditary angioedema, can have clinical problems that are a result of the role that the specific complement protein plays in the normal …

Jul 23, 2025 · When reviewing C3 and C4 test results, low levels are the most common and clinically significant finding. Low levels indicate that these complement proteins are being consumed by an …