The ANA test is a common test, considered a tool to assist in the detection of autoimmune diseases by taking a blood sample on the patient's body to test and detect antigen ANA existed in the blood. A positive test means an autoimmune response or more specifically, the body's own immune system mistakenly attacks its own tissue.
What Is Autoimmune Disease?
The immune system is also known as the antibody and is responsible for creating proteins that play a role in protecting the body against invasions from pathogens.
Antibodies are produced directly by red blood cells. When there are attacks from viruses, bacteria, and other agents, antibodies recognize and begin to fight these infectious organisms.
When antibodies begin to recognize antigens (foreign proteins of an infectious organism) to fight the infection, the anti-inflammatory system is activated thanks to the mobilization of other immune cells in the body.
Antibodies are not always 100% accurate. Sometimes, confusion occurs when antibodies mistakenly recognize normal proteins in the body for foreign objects that are dangerous to the body. At this time, the new antibody called auto antibody activates a protective regime and a cascade of inflammation leads to self-attack on the body.
These autoantibodies targets are ANA-Antinuclear antibodies. These are normal proteins in the nucleus of the cell.
Most people have autoantibodies in the human body, but only in very small quantities, causing no major concern. However, autoantibodies are present in large amounts or ANA in the body, this becomes a danger causing autoimmune diseases.
Autoimmune diseases are divided into 2 main groups: typical systemic autoimmune diseases such as systemic scleroderma, systemic lupus erythematosus … The other group is organ-specific autoimmune diseases such as autoimmune thyroiditis, autoimmune hepatitis.
What Is The ANA Test?
What is the ANA test? Simply put, the high sensitivity of the ANA (Antinuclear Antibodies) test will detect nuclear antibodies in the blood of the person being tested. Combined with the ANA test, will conduct some other tests such as X-rays and biopsy will help doctors diagnose the most accurately.
When Is The ANA Test Ordered?
When the patient has an autoimmune disease but often has a rather vague and confusing sign. ANA test is ordered by doctors when the patient's body has some symptoms but cannot find the specific cause as follows:
- Frequent feelings of dizziness, headache, fatigue, and unexplained fever.
- Hair loss, light-sensitive skin, numbness of limbs.
- Myositis, polymyositis.
- The nervous system is damaged.
- Inflammation of the pleura, pericardium.
- Have Raynaud's syndrome.
- The appearance of symptoms such as rheumatoid arthritis, hepatitis, polymyositis, unexplained thrombocytopenia, and lupus erythematosus syndrome …
4. Principle of The ANA Test
ANA test is a serum test, taking a blood sample of the patient to conduct tests based on technical principles such as Immunofluorescence, enzyme immunity, and luminescent immunization …
When the antibodies in the test sample react with the specific internal antibody in the reagent containing the tracer, either light absorbance or photometric will detect antibodies.
The sensitivity of the ANA test is quite high, so this is a common test that is often designated as the primary test for determining autoimmune states on the patient's body.
The ANA test is particularly highly specific in the detection of lupus. Because most patients who get Lupus through the ANA test will give positive results up to 95%.
How Is The ANA Test Done?
Before conducting the ANA test, the patient does not need to abstain from too much. Can eat and drink normally. The most important thing is to get adequate rest and stay relaxed for the best possible condition when taking samples. Do not use stimulants such as alcohol, tobacco, and coffee at least 12-24 hours prior to the test.
In addition, it is important to pay attention to information about medications and supplements that are being used, including prescription or non-prescription drugs. It is possible to bring medicine so that the doctor can check the ingredients most accurately. Because these drugs can interfere with test results causing false positives or false negatives.
At the beginning of the sample, the doctor will take about 3-4ml of blood from the vein on the patient's body straight into a test tube that does not contain anticoagulants or contains heparin anticoagulants. After that, plasma/serum centrifugation will be conducted. Serum/plasma samples after being collected will continue to be sent to the laboratory for testing by the following methods:
- Immune enzymes.
- Immunization of luminescent chemistry.
- Indirect immunofluorescence.
ANA test is like other normal blood drawing techniques, so the risk of harm to the body is completely negligible. There are some cases where the patient may feel slight pain or appear small bruises after the blood is drawn. But don't worry, the bruise should go away on its own for about a week.
However, test results can also be affected by a number of factors such as:
- Patients taking drugs or stimulants before taking blood but not informing the doctor causing false positives or false negatives. Especially, the use of blood pressure drugs and antiepileptic drugs.
- The process of preserving blood samples is not good, affecting the results.
- Patients who are infected with diseases caused by viruses such as infections, tuberculosis, and cancer also cause erroneous results.
Depending on where the test is conducted, there will be time to return results to different patients. As quickly as possible within a few hours after the test results. Based on the results, doctors will inform and advise patients.
Meaning of ANA Test Results
After determining the ANA index in the blood plasma through the tests, the following results will be given:
The ANA Test Result Was Negative
A negative result is when the ANA is less than 1.5 Index. This means that the autoantibodies were not found in the human body. If so, at a very low amount, below the threshold the machine can detect.
If symptoms still appear after the test, the test can be done to check again in about 4-6 weeks.
The ANA Test Result Was Positive
When the ANA index surpasses 1.5 Index, the result will be positive. That means finding the presence of autoantibodies in the blood of the patient. It is also unlikely that the patient has an autoimmune disease.
At this time, it is necessary to consult and diagnose by specialist doctors to conduct more specialized tests and exploit more symptoms on the patient's body. Only then can have exact conclusions and treatment regimen for the patient.
In healthy people, the present rate of ANA is at 3 – 15%. However, this rate also varies greatly depending on age. Specifically, the production of autoantibodies will gradually increase from 10 to 37% in people in good health over 65 years old. Usually, the ratio of ANA in women will be higher than in men.
When infected with viruses, even a healthy person is likely to give a positive ANA test result. Although these autoantibodies are only short-lived.
The ANA Test Helps Detect The Cause of Scarlet Fever
Lupus scarlet fever is a disease that is very dangerous to the health of the patient, affecting many organs such as the heart, liver, lungs, brain, blood … This is a disease with a complicated mechanism. Usually when lupus erythematosus is found to have a rate of up to 80 – 90%.
Signs of lupus are often tired, headache, shortness of breath, swelling of the joints, relatively sensitivity to light … Especially, the most noticeable sign is a butterfly-shaped rash on the cheeks.
An ANA test will help find the exact cause of scarlet fever. Since then, there are appropriate treatment regimens such as using immunosuppressants or using biological drugs to reduce the symptoms of the disease.
Besides, having a reasonable diet, regular exercise, limiting the use of stimulants and regular check-ups is also some of the methods to help improve the disease effectively.
Thus, the ANA test is of paramount importance in helping doctors diagnose autoimmune diseases, especially lupus. Since then, there is an active treatment direction to protect the health of the patient before it is too badly affected by the disease.
Not only that, but this is also a common test to monitor common diseases on the human body. When symptoms of an autoimmune disease appear or signs of unknown cause, it is necessary for hospitals to be promptly examined and treated according to a specific and effective regimen.
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