What You Need to Know About the CH50 Test

What is the CH50 test?

CH50 stands for the complement blood test. This test measures the activity and the amount of the complement protein in the blood. The complement proteins are part of the complement system. A complement system consists of proteins that work with the immune system to find and fight disease-causing bacteria and viruses. 

Complement proteins have nine major proteins labeled as C1 to C9. The tests can be done on individual proteins or all together, and the most commonly tested individual complement proteins are C3 and C4. A CH50 or CH100 test measures the activity and amount of significant complement proteins. 

If the result shows that your complement protein level is not average or the proteins are not active with the immune system, it might indicate autoimmune disease or other health issues. The nine major complement proteins labeled as C1 to C9 are measured with the CH50 test.

What is CH50 used for?

A complement blood test is done to diagnose or monitor autoimmune disorders like

• Lupus- a disease that affects multiple parts of the body and is chronic. 
• Rheumatoid arthritis – is a disease that causes swelling and pain in the joints, commonly in the feet and hands. 

It even helps diagnose viral, fungal, and bacterial infections. 

Why do you need the CH50 test?

Total complement activity, also known as CH100 or CH50, is thought to represent your entire complement system. The tests are performed to discover a specific disease, or the doctor might prescribe the test to detect suspected underlying conditions. A complement blood test is necessary when you have these symptoms of an autoimmune disorder, mainly Lupus, or to check if the ongoing treatment is working or not. The symptoms are

• A butterfly-shaped rash over your nose and cheeks. 
• Mouth sores
• Hair loss
• Sensitivity to sunlight
• Fatigue
• Swollen lymph
• Chest pain
• Fever
• Joint pain

This test is also used to monitor patients under treatment for autoimmune disorders. If they have active lupus erythematosus, they may have lower-than-normal levels of C3 and C4 complement proteins. For those with rheumatoid arthritis, the activity of complement proteins may be regular or higher than average but lower than usual in the joint fluids. Those diagnosed with bacterial infections and shock have very low C3 and components known as alternate pathways. C3 is also low when someone is diagnosed with fungal infections or parasitic infections like malaria.  

What happens during the test?

 A healthcare professional collects blood samples from your arm with a needle and extracts the blood. The sample is collected in a vial. 

How does the test feel?

The blood sample is extracted through a needle; some might feel a slight pain, whereas others might feel a prick. Later, there might be a little stinging feeling. 

How should you prepare for the test?

There is no specification on how you should be prepared, so there is no special preparation for the test. 

What do the results mean?

After the test, if your result shows a low amount and decreased activity of your complement proteins, then it may indicate: 

• Lupus nephritis 
• Lupus erythematosus
• Rheumatoid arthritis
• Cirrhosis
• Kidney disease and kidney transplant rejection 
• Hereditary angioedema
• Malnutrition 
• A recurrent infection 
• Glomerulonephritis
• Hepatitis

If the result shows the increased activity of complement proteins or a higher amount of the same, then it means

• Kind of cancer, like leukemia. 
• Ulcerative colitis 
• Infections

Normal Results 

The result is said to be normal when,

• Total blood complement level: 41 to 90 hemolytic units. 
• C1 levels: 14.9 to 22.1 mg/dL
• C3 levels: 88 to 201 mg/dL
• C4 levels: 15 to 45 mg/dL

mg/dL = milligrams per deciliter.

The measurements are common measurements of results, and they may vary when different measurements or tests are taken. 

The Risks 

The risks when having your blood drawn include 

• Excessive bleeding
• Feeling lightheaded
• Hematoma- when blood accumulates under the skin.
• Infection- which is typical whenever skin is broken. 

The CH50 blood test analyzes all the activity of the complement system and evaluates the activity path of the complement system. This test is often performed to evaluate the complement activity when complex immune diseases, inflammation of the kidney, or abnormal proteins get thick in cold temperatures. Also, read other health blogs on this site.

A complement system is a group of almost 60 proteins in the blood or on the surface of cells. The proteins work with the immune system to protect the body by removing dead cells, foreign materials, and infections. People may rarely get a deficiency of these complementary proteins, and those with these deficiencies are prone to disease and autoimmune disorders.

Read: A Brief Choghadiya in Astrology and time calculation