What is a C4 blood test?
C4. Complement component 4 is a blood test that measures the activity of a certain protein. This protein is part of the complement system. The complement system is a group of nearly 60 proteins that are found in the blood plasma or on the surface of some cells.
What is a normal C4 level?
The normal range for a complement C4 blood test is 16 to 48 milligrams per deciliter (mg/dL), or 0.16 to 0.48 grams per liter (g/L). Your complement levels will often shoot up dramatically just after an infection or injury.
What does C3 and C4 test for?
C3 and C4 are the most commonly measured complement components. A complement test may be used to monitor people with an autoimmune disorder. It is done to see if treatment for their condition is working. When the complement system is turned on during inflammation, levels of complement proteins may go down.
What does C4 protein do?
Complement component 4 (C4), in humans, is a protein involved in the intricate complement system, originating from the human leukocyte antigen (HLA) system. It serves a number of critical functions in immunity, tolerance, and autoimmunity with the other numerous components.
What does it mean if your C4 is high?
There are several reasons why you might have high complement C4 levels over 45 milligrams per deciliter. If you have had a recent injury or infection, you’re likely to have more C4 in your blood. High complement C4 levels can also be found in people with cancer or inflammatory bowel disease like ulcerative colitis.
What causes high C4 complement levels?
Answer: Possible causes of elevated complement levels include: cancer, viral infections, non-alcoholic fatty liver disease, metabolic syndrome, obesity, diabetes, heart disease, autoimmunity (psoriasis, ulcerative colitis).
Why is my C4 low?
Low complement C4 levels under 15 milligrams per deciliter might indicate some types of health problems and conditions such as: Malnutrition. Lupus. Liver diseases such as hepatitis and cirrhosis.
What causes low C4?
A low level of C4 is associated with autoimmune diseases, such as lupus and rheumatoid arthritis. The complement C4 test only requires basic preparation and carries few risks. The sample of your blood will be sent to a laboratory for analysis.
Can C3 and C4 be normal with lupus?
Lupus patients usually have low C3 and C4 levels during disease flares because of activation of the complement system by immune complexes (ICs) [1]. However, in remission periods, complement levels reach normal values.
What causes high C4?
Possible causes of elevated complement levels include: cancer, viral infections, non-alcoholic fatty liver disease, metabolic syndrome, obesity, diabetes, heart disease, autoimmunity (psoriasis, ulcerative colitis).
Does low C4 mean lupus?
People with lupus normally have low complement C4 levels, especially when the disease is actively causing inflammation. If you have lupus, high levels of C4 can indicate that your body is responding to treatments or medications you are taking to manage your condition.
What disease can cause a high complement level?
If your results show higher than normal amounts or increased activity of complement proteins, it may mean you have one of the following conditions: Certain types of cancer, such as leukemia or non-Hodgkin lymphoma. Ulcerative colitis, a condition in which the lining of the large intestine and rectum become inflamed.