The C3 C4 blood test combination, which are individual tests that are commonly referred to as “compliment tests,” are used to determine if there is a deficiency or an abnormality in the compliment system.
What is the compliment system? It’s part of the immune system which works to enhance the abilities of phagocytic cells and antibodies to remove damaged cells and microbes. Because it can promote inflammation, the C3 C4 blood test is used to determine if systemic activity is contributing to the physical signs and symptoms a patient might be experienced.
This system can be activated in a wide variety of ways, but the end result is always the same: the formation of an attack complex which targets cell membranes. It may attack pathogens or, in an autoimmune disease, attack healthy parts of the body.
This blood test combination is often the starting point in the diagnostic process to determine what is affecting patient health.
When is the C3 C4 Blood Test Ordered?
The most common reason for ordering these blood tests is for inflammation that does not have an explanation. It may also be ordered for patients who are experiencing edema or may have symptoms that are similar to an autoimmune disorder
It may also be ordered to determine the severity of a diagnosed condition. It is also sometimes ordered as part of an ongoing process of monitoring a diagnosed condition.
The results of complement testing may be used to help diagnose the cause of a microbial infection that is recurring more than it should. It also helps a medical provider be able to diagnose an acute or chronic autoimmune disease, such as rheumatoid arthritis. Complex conditions, including vasculitis and kidney disorders, are also monitored frequently with the C3 and C4 blood tests.
What Do My Test Results Mean?
The C3 and C4 blood tests are generally communicated as having decreased or increased levels, depending on the health condition that is being considered by a medical provider.
Compliment levels are typically decreased when there is an acute or chronic condition that may be due to an infection, disease, or even a hereditary condition. This includes acquired or hereditary angioedema, various types of kidney disease, liver disease, malnutrition, or an immune complex disease.
When compliment levels are increased, then this is an indication that there is either acute or chronic inflammation occurring somewhere in the body. This may be because of sarcoidosis, ulcerative colitis, thyroid conditions, or an acute myocardial infarction. In children, increased compliment activity may be an indication of juvenile rheumatoid arthritis.
In certain cases, increased levels as a test result for the C3 and C4 blood tests may also be an indication of cancer. Leukemia, sarcoma, or Hodgkin’s Lymphoma are all known to produce these compliment results. Simply having an increased test reading is not an indication that cancer is present. Other tests must be performed in order to confirm the diagnosis.
Here’s What You Need to Know
The results of these compliment tests cannot be used as a diagnostic tool. They simply let a medical provider be able to know that the immune system is involved with the signs and symptoms being experienced by the patient.
The C3 and C4 blood tests are generally ordered whenever a patient is experiencing the general symptoms of inflammation, but without a known cause. This may include joint pain and stiffness, a swollen joint that becomes warm to the touch, redness, loss of function, fever, or pain at the inflammation site.
Inflammation is not the same as an infection. Inflammation is the body’s response to the invasion of a fungus, virus, or bacteria. Chronic inflammation can lead to more severe health conditions, which is why it should be examined by a medical provider. Signs of chronic inflammation include an increase in fatigue and depression, common stomach aches and pains, or feeling tired even when you get enough sleep at night.
No test preparation is needed. The blood sample will be taken from the arm on the same day the test is ordered.
The C3 C4 blood test combination is a common and effective way to detect compliment system activity. If you are experiencing the signs and symptoms of acute or chronic inflammation, then use this guide to speak with your medical provider about your personal health.
Although it is not a screening tool, it can help your doctor begin the investigative process that may be able to resolve the underlying condition affecting your health so that you can begin to feel better.