Table of contents:
- Definition
- What is a tissue type test?
- When do I need to take a tissue type test?
- Precautions & warnings
- What should I know before undergoing a tissue type test?
- Process
- What should I do before undergoing a tissue type test?
- How is the tissue type test process?
- What should I do after undergoing a tissue type test?
- Explanation of the Test Results
- What do my test results mean?
Definition
What is a tissue type test?
The tissue type test is a blood test that identifies substances called antigens on the surface of body cells and tissues. By checking for antigens, it can be seen whether your donor's tissue is safe (compatible) for transplantation to another person. This test can also be called HLA Typing. Antigens can differentiate between normal body tissue or foreign tissue (for example, tissue from another person's body). This type of tissue helps find the most suitable tissue for a particular tissue or blood cells (such as platelets). In some cases, a tissue type test can be done to see if a person is at risk for certain diseases that cause the body to attack its own cells, such as autoimmune diseases.
A special pattern of antigens (called a tissue type) is present on each person's cells and tissues. Half of each person's antigen comes from (is inherited by) the mother and half from the father. Identical twins have the same pattern, but other people have their own special patterns. Siblings have a 1 in 4 chance of having identical antigens. Each person's antigen pattern can be “fingerprinted” through a tissue type test.
- the more suitable the antigen, the more likely the organ or tissue transplant will be successful
- the more similar the antigen patterns of two different people, the more likely the two antigens are related to one another
- Some diseases (such as multiple sclerosis or ankylosing spondylitis) are more common in people who have certain antigenic patterns. It is not known why
Two main antigen groups are used for the tissue type test. Class I has three classes of antigens (HLA-A, HLA-B, HLA-C) that are found on several types of blood cells. Class II has one class of antigen (HLA-D) which is found only on certain cells in the body. There are different types of antigens in each category.
When do I need to take a tissue type test?
This tissue type test is done for:
- see if the antigen pattern matches a particular tissue or organ donor (including blood platelet transfusions or bone marrow transplants). The success of the transplant depends on how closely the antigen pattern matches. The antigen pattern is most likely to be similar when the donated organ or tissue comes from a close relative
- see how close the blood ties are between two people. If the antigen patterns are very similar, it is possible that the two people are related by blood. But this type of tissue cannot prove definitively that the two people are related by blood. A tissue type test can be done as part of a DNA test to check the relationship between the father and the biological child
- find people who may have a high risk of developing autoimmune diseases
Precautions & warnings
What should I know before undergoing a tissue type test?
Although the type of tissue cannot prove that two people are related by blood, this test can show how likely the two people are related. This type of tissue may be used as part of a lawsuit when there are problems related to blood relations.
Having an antigen pattern associated with a particular disease does not mean that it is present or will definitely appear in you. Your doctor will talk with you about the possibility of developing this disease.
Process
What should I do before undergoing a tissue type test?
You don't need to prepare for this test. If you donate tissue or blood cells, your doctor may want to talk about your medical history such as a history of cancer, infections, high-risk behavior, drug use, exposure to toxins, and traveling abroad. So it's important to understand whether your donor network can be used.
How is the tissue type test process?
Your doctor will clean a small area of the arm or elbow with an antiseptic or alcohol. In some cases, the doctor will wrap an elastic band around the top of your arm to increase blood flow. This makes collecting blood from your veins easier.
Your arm will then be pierced with a syringe which will then enter your vein. Blood will collect in a tube attached to the tip of the needle. After enough blood has been drawn, the doctor will remove the needle. Then the doctor will apply a cotton swab and a bandage to stop the bleeding where the syringe was injected.
What should I do after undergoing a tissue type test?
You will be promised time to get the test results. Your doctor will explain the test results that are meaningful to you. You must follow the doctor's instructions.
Explanation of the Test Results
What do my test results mean?
Specific HLA genes or antigens will be identified during HLA classification for the compatibility of the transplanted organ and tissue. The genes and / or antigens of the transplant recipient will be compared with potential donor genes / antigens. The results showed the number of suitable and unsuitable antigens. The greater the number of matches, the greater the chance of a successful transplant. "Zero mismatch" indicates a high probability that the organ or tissue will not be rejected by the recipient.
The absence of HLA receptive antibodies to the HLA antigen donor is very important. Matching donors with recipients who have developed antibodies should be considered carefully because the more developed a person's HLA antibodies, the more likely they are to reject them.
A positive cross result is usually interpreted as a high-risk transplant. These people are at risk for refusing a transplant, which may or may not be treated with various immunosuppressant drugs.
