Overview

Complement Levels - C3, C4 are blood tests that measure the levels of two proteins, C3 and C4, that are part of the complement system. This system plays a role in the bodys immune response by helping to destroy foreign invaders such as bacteria and viruses. The test is performed by taking a blood sample from the patient and analyzing it in a laboratory. Abnormal levels of C3 and C4 can indicate certain autoimmune diseases or infections.

Who should do this test?

Patients with suspected autoimmune diseases: Complement levels such as C3 and C4 are typically measured in patients with suspected autoimmune diseases such as lupus, rheumatoid arthritis, and vasculitis. These tests can help diagnose and monitor disease activity in these patients.

Patients with recurrent infections: Complement deficiencies can increase the risk of recurrent infections, particularly with encapsulated bacteria such as Streptococcus pneumoniae. Patients with recurrent infections may require complement level testing to identify any deficiencies that could be contributing to their infections.

Patients with kidney disease: Complement activation can contribute to the development and progression of kidney disease. Complement level testing may be used to monitor the activity of complement in patients with kidney disease and to guide treatment decisions.

What to do if the test is abnormal?

Schedule an appointment with a healthcare provider: If someones complement levels (C3, C4) are abnormal, they should schedule an appointment with their healthcare provider to discuss the results and determine the underlying cause of the abnormality.

Undergo further testing: Depending on the individuals medical history, symptoms, and physical examination, the healthcare provider may recommend further testing to determine the underlying cause of the abnormal complement levels.

Follow the treatment plan: Once the underlying cause of the abnormal complement levels has been identified, the healthcare provider will develop a treatment plan. It is essential to follow the treatment plan as prescribed to manage the underlying condition and restore the complement levels to normal levels.

What is the normal range of C3 and C4?

The normal range for adult males is *,the normal range for adult females is *