Table of contents:
- Definition
- What is an anticentromere antibody?
- When should I take anticentromere antibodies?
- Precautions & warnings
- What should I know before taking anticentromere antibodies?
- Process
- What should I do before taking anticentromere antibodies?
- How is the anticentromere antibody process?
- What should I do after taking anticentromere antibodies?
- Explanation of the Test Results
- What do my test results mean?
Definition
What is an anticentromere antibody?
This test is used to diagnose CREST syndrome.
The centromere is the main part of the chromosome which divides the chromosome into sections. The centromere is attached to the mitotic spindle at the time of cell division.
Centromere antibody is a type of antinuclear antibody. These antibodies were detected in patients with CREST syndrome, a variant of scleroderma. CREST syndrome shows infiltration lime syndrome, Raynaud's phenomenon, esophageal paralysis, finger stiffness and telangiectasias. In contrast, anti-centromere antibodies are rarely found in patients with scleroderma, a disease that is difficult to distinguish from CREST syndrome.
Approximately 50% - 90% of anti-centromere antibodies are found to be positive in patients with scleroderma and 82% - 96% in patients with CREST syndrome. The sensitivity level of this test is 95%.
When should I take anticentromere antibodies?
This test is needed if you get positive results from the antinuclear antibodies (ANA) test and have more than one symptom of CREST syndrome.
Symptoms include:
- calcification - accumulation of calcium in the body
- Raynauld's phenomenon - narrowed blood flow in the fingers and toes, causing them to become pale and purplish
- esophageal dysfunction - difficulty swallowing, acid reflux and heartburn
- scleroderma - the fingers and skin on the hands are tightened, thickened and shiny
- vasodilation - red patches on the skin caused by angioedema.
Precautions & warnings
What should I know before taking anticentromere antibodies?
There was no correlation between antibody levels and the severity of CREST syndrome.
There may be a positive ACA result in some diseases such as systemic lupus erythematosus, rheumatoid arthritis, or primary biliary fibrosis.
Usually, only patients with CREST symptoms are screened for. However, some people may also be ACA positive before experiencing symptoms. ACA can be checked at the same time as tests for other autoimmune diseases.
It is important that you understand the above warning before running this test. If you have any questions, consult your doctor for further information and instructions.
Process
What should I do before taking anticentromere antibodies?
Things that need to be considered before undergoing the test:
- pay attention to the doctor's explanation of the test process
- fasting before the test is not required
How is the anticentromere antibody process?
The medical personnel in charge of drawing your blood will take the following steps:
- wrap an elastic belt around your upper arm to stop blood flow. This makes the blood vessel under the bundle enlarge making it easier to insert the needle into the vessel
- clean the area to be injected with alcohol
- inject a needle into a vein. More than one needle may be required.
- Put the tube into the syringe to fill it with blood
- untie the knot from your arm when enough blood is drawn
- attaching gauze or cotton to the injection site, after the injection is complete
- apply pressure to the area and then put a bandage on
What should I do after taking anticentromere antibodies?
While you generally won't feel any pain, some people can feel pain when a new needle is injected. However, when the needle is in the blood vessel, the pain is usually not felt. Pain depends on the skills of the nurse, the condition of the blood vessels and your sensitivity to pain.
After the blood draw, it is recommended that you wrap it with a bandage and apply light pressure to your vein to stop the bleeding. You can do your normal activities after the test.
If you have any questions about this test process, please consult with your doctor to understand more.
Explanation of the Test Results
What do my test results mean?
Normal result:
Negative (If the result is positive, a serum count will be performed)
Abnormal results:
- weak positive: positive is combined with titer (1:40 for human epithelial cell types, 1:20 for kidney cells).
- medium positive: detectable when diluted once compared to benchmark.
- strong positive: detectable when diluted twice compared with benchmark.
If your result is positive: You have CREST syndrome.
Consult your doctor if you have questions about test results
