HLA (Human Leukocyte Antigens) typing is a sequencing-based test to find the best match for organ and allogeneic bone marrow transplant. If the donor’s HLA is identified as an invader by the recipient, it will lead to rejection. Selecting the donor critically impacts the outcome of transplantation.
Purpose of HLA Typing
HLA typing is usually done to identify those who would be able to offer the safest tissue transplants. Every potential tissue recipient needs to get an HLA typing test done. Anyone willing to donate tissues also needs to get the test done.
Even if you are a relative of the recipient, you will have to get the test done. People who are terminally ill or passed away recently also need to get their HLA test done to become organ donors. The best possible donor will match the HLA patterns of the recipient.
HLA matching reduces the risk of a transplant. It ensures that long-term complications after a transplant can be avoided. Without a good match, organ rejections are quite common.
Some people also need to get the HLA testing done after transplant surgery. It helps determine whether their body is making antibodies to fight the transplanted tissue. It often indicates organ rejection and shows that the transplant may not be successful.
The HLA System
The HLA system comprises a group of genes. They have a crucial role in the immune system of the body. The proteins made by these genes lead to the major histocompatibility complex.
The proteins usually remain attached to most cells inside the body, except the red blood cells. Several variations exist in these proteins, and the cells in the body look for these variations. Your body can also identify which cells are yours by looking at the variations.
HLA Typing Process
The HLA typing test revolves around looking at HLA genes inherited by your body. You can consider them colorful strings. You will come across different HLA genes and their numerous variations.
The variations indicate the possibility of multiple color combinations. All these variations combine to form your specific HLA type. The different components of HLA typing are as follows:
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Antibody Testing
HLA typing looks for antibodies targeted to specific HLA proteins. The immune system is tasked with creating antibodies. If your body has antibodies against an HLA string, it will be prepared to attack that particular color string.
Therefore, the antibodies will also attack the protein when it’s transplanted. Therefore, the transplant will be unsuccessful. You shouldn’t receive an antibody from someone when you have antibodies against their HLA proteins.
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Lymphocyte Crossmatching
Lymphocyte crossmatching is also a part of HLA typing. Lymphocytes are immune cells inside the body. Lymphocyte crossmatching involves checking whether the recipient has antibodies against proteins inside a donor’s lymphocytes.
Interpretation of HLA Typing Results
The reports from your HLA typing test won’t mean much to you because it contains technical terms. But a healthcare provider will be able to determine whether your HLA type is compatible with that of the donor or recipient.
How Many HLA Matches Are Required?
Ideally, the HLA patterns of the donor and recipient must be identical. However, it’s not always possible. The number of matches required depends on the type of the transplant and various other medical conditions.
Finding a good match for a stem cell transplant is more challenging than finding a match for solid organ transplantation. Both procedures involve the risk that the cells of the recipients will start attacking the transplanted tissue. But in stem cell transplant, the donated cells can also attack the recipient. This attack is medically called graft-versus-host-disease.
The percentage of matches is higher for people receiving stem cell donations than for the ones receiving a solid organ. The number of HLA matches you need for successful transplantation often varies across medical institutions and healthcare providers. But some situations permit a transplant with fewer matches.
In some cases, your healthcare provider might allow you to go ahead with the transplant even when you don’t find an exact match. In other cases, doctors will prescribe other treatments while you wait for the perfect match to become available.
Closing Thoughts
The results of HLA typing must be accurate to guarantee the success of the transplant. Therefore, you must get the test done from a reliable pathological lab. Metropolis is one of the best options to get HLA typing done in India.