Complement Protein Test is also known as the C-Reactive Protein (CPR) Test that measures a special type of protein concentration in the blood serum. This protein is produced by the liver and is present when there is acute infection or inflammation in the body. The CPR is important in the immunologic defense mechanism by interacting with the complement system.

 

Types of Complement Protein Test Works           

There are two categories under which the Complement Protein Test or CPR is used to determine the abnormality or deficiency in the complement system that is the cause of the disease in the patient. They are Complement Component 3 (C3) and Complement Component 4 (C4).

Ailments Diagnosed

Complement Protein Test are used by the doctors to diagnose inflammation, angioedema or chronic microbial infections. Apart from these it is also used for testing and monitoring immune complex-related ailments such as rheumatoid arthritis, serum sickness, glomerulonephritis (a kidney disorder) and visculitis. Autoimmune diseases that are chronic or acute like systemic lupus erythematosus (SLE) can also be diagnosed with CPR Test. In the case of the diseases the complement levels drop or get cleared from the blood as the immune complexes form.

When is Complement Protein Test Ordered

A person suffering from unexplained inflammation or having the symptoms of autoimmune disorder can be asked to take the test. Also a doctor can ask to get the test done if he suspects a patient suffering from some kind of immune complex-related disease and needs to check the complement system of the person. Generally C3 and C4 tests are ordered together as it is important to find out the relative levels. The Complement Protein Testing gives the doctor an idea about the severity of the disease by the decrease of the complement levels.

Deducting the Complement Protein Result

There can be increase or decrease in the complement protein level, if there is a decrease in the level due to hereditary cause, the individual is them prone to recurrent microbial infection. Decrease in the Complement Protein can also be linked with development of autoimmune diseases.  The increase in the complement protein generally can be seen during chronic or acute inflammation. In both the cases complement protein can return to normal when the cause of the abnormality is treated.

­Arthritis and Complement Protein Test

The test is used mainly for rheumatic arthritis, where there is inflammation and eventual degeneration too. Doctor uses this test to monitor the flare-up of the disease as well as to evaluate the success of a particular treatment on the arthritic patient.