Reasons For Elevated & Low Levels of Complement CH50

Submitted on March 27, 2012

Complement CH50 is a blood test that helps us determine whether protein abnormalities and deficiencies in the complement system are responsible for any increase in autoimmune activity. The test basically helps to closely monitor autoimmune disease activity. The test is also known as CH50, Total Hemolytic Complement activity, Total complement, C3, CH100 and C4. The test also goes by the formal names of Complement Component C3, Complement activity and Complement Component C4. The complement system is composed of a set of blood proteins that circulate and work with each other to boost immunity and to promote inflammatory responses. They primary perform the function of destroying viruses and bacteria. The primary components of the complement system are nine in number and they are designated from C1 to C9.

The complement system is different from the acquired immune system, as it does not generate specific antibodies that can destroy a viral agent on target. The complement system thus need not be exposed to a virus earlier to remember to destroy it. Instead, it forms part of the body's innate immune system which responds to foreign substances very quickly and can identify them by studying the outer membranes of these foreign cells and microorganisms.

Why Is It Conducted?

You should get a Complement CH50 if you suspect that you have a bacterial infection. Other symptoms for which the Hemolytic Complement activity needs to be performed are unexpected edema or inflammation. Any symptoms related to an autoimmune disorder may require a Complement total. Acute chronic illnesses that disturb the normal functioning of the complement system also require a Complement Ch50 test. C4 and C3 are performed to determine whether specific abnormalities or deficiencies of the complement system are causing a chronic condition or disease in a patient. To determine the level of integrity of the classical complement pathway a total complement activity may be prescribed. Total complement activity is also called CH100 or Ch50.

Reasons For High & Low Levels In The Complement System

The levels in the complement system may be low on account of hereditary reasons. It is also possible that they are low on account of a high level of consumption. If one of the proteins of the complement system is deficient on account of hereditary reasons, then it may lead to recurring microbial infections. Deficiency of a complement system protein could also lead to autoimmune disease. Once the underlying chronic condition is treated, then the levels of protein in the complement system will return to normal. A decrease or increase in complement levels measured by the Complement CH50 will not be an adequate indicator of what is wrong. The test however, does help your doctor to be in a position to gauge whether or not the immune system is involved with your ailment in any way.

What are complement CH50 normal levels?

Under normal circumstances, the total level of the blood complement should be 41 to 90 hemolytic units. Given below are the normal readings of some of the blood proteins:

  • C1 Levels: 16 mg/ dl to 33 mg/ dl
  • C3 Levels: 88 mg/ dl to 252 mg/ dl in men and 88 mg/ dl to 206 mg/ dl in women
  • C4 Levels: 12 mg/ dl to 72 mg/ dl in men and 13 mg/ dl to 75 mg/ dl in women

It is important to bear in mind that the complement CH50 normal levels may vary a bit from one lab to the other. Therefore, it is important to refer to a health care provider to determine if the complement CH50 levels are normal or not.

What does elevated complement CH50 levels mean?

In case your test results reveal elevated complement CH50 levels, it could be an indication of certain serious health conditions, which include cancer, ulcerative colitis and infections.

What leads to low complement CH50?

It is a lot more common to see low complement CH50 levels, which is caused by several factors. In fact, low complement CH 50 can also be heredity. The deficiency of even one of the proteins in the body can lead to autoimmune diseases or recurring microbial infections. Given below are some of the conditions that low complement CH50 could be an indication of:

  • Malnutrition
  • Kidney transplant rejection
  • Heredity angioedema
  • Cirrhosis
  • Lupus nephritis
  • Hepatitis
  • Systematic lupus erythematosis
  • Glomerulonephritis

In case of low or elevated complement CH50 levels, the patient will need to undergo treatment, which includes the use of certain drugs. Once the condition causing abnormal levels is treated, the complement system usually returns to normal. However, after initiating the treatment, health care providers may conduct a complement CH50 assay test, to determine the efficiency of drugs.

The increase or decrease in the complement levels assessed by the Complement CH50 test is not always an accurate indicator of what the exact problem is. However, this test enables a doctor to determine if the immune system is involved with the ailment in any way.

It is a very common to see low complement CH50 levels, which is caused by several factors. In case your test results reveal elevated complement CH50 levels, it could be an indication of certain serious health conditions.