COMPLEMENT 4 (C4)

The complement 4 (C4) test measures the level of C4, a protein component of the complement system, in the blood. The C4 test is used to diagnose and monitor autoimmune and inflammatory conditions, such as systemic lupus erythematosus (SLE), rheumatoid arthritis, and kidney diseases. Low levels of C4 can indicate an active immune response, complement system deficiency, or genetic deficiency. The test is valuable for assessing immune function, diagnosing underlying conditions, and guiding treatment decisions for autoimmune and inflammatory diseases. It provides important information for managing immune-related disorders and ensuring appropriate medical intervention.