Organ transplants are a widely known topic. Organ transplants and research over growing new organs receive lots of hype from media outlets. However, there is a very important step in the organ transplant process that not many people know about or ever hear about. It’s the process of actually finding an organ that will match up with organ recipient’s immune system.
HLA (Human Leukocyte Antigen) is an important molecule used in cancer research and organ donations. It’s important for organ donations because HLA typing is necessary to make sure an organ will cooperate with the organ receiver’s body. HLA typing identifies the different HLA genes a person has as well as the antigens located on those molecules. The antigens are incredibly important to the body’s immune system. They help the body recognize what cells belong and what cells are foreign. The foreign cells trigger an immune response that produces antibodies, which can be fatal if an organ recipient has an immune response to their new organ.
HLA typing is similar to blood typing for blood transfusions because it is done to ensure the donor organ and the organ receiver have similar HLA types. However, HLA is hundred times more complex than blood because there are over hundreds of different types of HLA molecules. Every person has a unique arrangement of HLA alleles. You might be asking yourself then “How is it possible for someone’s body to accept an organ if everyone has a different HLA combination?” After all, there are around 1122 different HLA alleles.
While there are many different types of HLA, there are around 11 major HLA molecules that are present in a huge majority of the population. In fact, one of the molecules is present in 60% of the population. Thus, by matching the most prevalent HLA molecules, organ donation matches can be successfully made.
However, along with matching the HLA molecules, HLA antibodies must also be screened for as another step in the process of ensuring donor-recipient compatibility. HLA antibodies associated with the dominant HLA molecules for an individual will definitely be present but there are surprise antibodies. Sometimes people will develop immunities to certain HLA antigens that are not from within their own body; usually from circumstances like pregnancy, blood or platelet transfusions, or previous organ transplants . Thus these antibodies must also be taken into consideration.
The process of organ transplants is complicated and it all starts with HLA typing to find the best possible match.