Why Is HLA Close Match Important for a Transplant?
March 03, 2021
Every year, a number of new diseases and infections come to the fore. And so does the need to find effective ways of treatment. In such testing times, stem cell transplant has fast emerged as an effective treatment option with life-saving benefits. However, this process can be truly beneficial to those seeking it only if the receiver finds a donor who is a perfect match. Today, we discuss Human Leukocyte antigen (HLA) typing and matching, and how a good match can make a difference.
What are HLA-proteins?
HLA stands for Human Leukocyte Antigen. HLA are proteins, or markers, are found on most cells of the body. They are located on the while blood cells as well other tissues of the body. The human immune system uses these HLA markers to differentiate between those cells that belong to your body and those that do not. There are four general groups of HLA - HLA-A, HLA-B, HLA-C and HLA-DR. Each of these four groups consist of further sub-categorized HLA proteins with different numerical designation. When two people have the same type of HLA proteins, including the subcategories, then they are considered to be a “good match.” This means that the immune system of these two people is compatible with each other 1 2.
Children often inherit HLAs from their parents. If two siblings inherit the same type of HLA from their parents, they are called an ‘identical match’. However, this isn’t as simple as it sounds. There is always a possibility of siblings from the same family inheriting different combinations of HLA. Because, when we say inheriting, it means inheriting HLA in sets of four HLA groups - A, B, C and DR. These sets are known as haplotype, which means “half set of proteins”. Each parent contributes one haplotype to the children. Eventually, children receive four different haplotype combinations from their parents.
There is a 25% chance that a child may inherit the same HLA haplotype as that of another sibling
25% chance that the child may ‘not’ inherit any of the same HLA haplotype as that of another sibling
50% chance that a child might share 1 haplotype with another sibling
Thus, there is a 1 in 4 chance of finding a perfect match with a sibling2
Role of HLA proteins
What is HLA?
HLA = Human Leukocyte Antigen
Immune cells Leukocyte HLA- barcode on cells to help identify Selv vs. Non self cells or uninfected vs. infected cells
HLA proteins play an important role in helping the body’s immune system to recognize and differentiate between the body’s healthy protein cells from that of infectious foreign body cells. Thus, helping the body avoid killing its own healthy cells. A similar situation arises when a transplant is required for treatment of a disease. The immune system can assume the donor organ/cells as a foreign body and reject it. Thus, it is important to find a donor whose HLA type matches that of the receiver in order to avoid a rejection of the transplant. As we have already discussed, finding a ‘good match’ may not be easy at all, even among siblings. In such situations, the HLA proteins typing and matching beforehand helps in determining the chances of a rejection3.
HLA Typing: Purpose and Process
An HLA Typing test, like LifeCell’s StemMatch, is a genetic test the purpose of which is to identify an individual’s HLA antigens in the immune system. This test is important to determine if a person can safely use stem cells for transplant. StemMatch not only provides you with this information, but also goes a step ahead by helping you find the right match in LifeCell’s cord blood registry. StemMatch instantly gives you the exact number of matching stem cell units.
The process of LifeCell’s StemMatch test is quite simple. All you need to do is
Sample collection -Child’s cord blood and adult’s peripheral blood
Quick Results - You’ll receive comprehensive test results within 15 working days!
Role of HLA Matching in a successful transplant
There are quite a few hurdles when it comes to finding a donor who is a good match, especially for Indians. Due to India’s diverse population, there is a 1 in 10,000 to 1 in 1,000,000 chance of finding a donor with the right genetic match. There are other problems as well such as a high rate of donor drop-outs, public bank limitations, low inventories, and lack of funds for the functioning of the registry. Also, there is <10% probability of finding a matching donor in a public bank.
However, with LifeCell’s StemMatch, such hurdles are eliminated at an early stage. As you can see in the image, Esha, who suffers from blood cancer, needs a matching HLA type. The instant access to vital information about matching donors helps Esha find one in Dev, thus ensuring a successful transplant.
Finding a ‘good match’ via HLA-typing before a transplant offers benefits such as:
Improved chances of a successful transplant
Reduced risk of graft rejection (probability of stem cell rejection)
Promotes engraftment (growth & development of healthy blood cells)
Reduces the risk of complications including graft-versus-host disease (GVHD)
As stem cell transplant continues to break new grounds in effective treatment of diseases, there is a greater need for us to recognize the importance of HLA-typing and the role it plays in a successful transplant. In the midst of this, LifeCell’s StemMatch offers you a quick and hassle-free opportunity to help you make the right decisions regarding stem cell transplant.
Your family’s healthy future is now in your hands. Become a LifeCell member and avail numerous benefits such as pocket-friendly plans, financial assistance unlimited retrievals and double the protection for your baby’s previous stem cells. If you have any further questions, we would love to hear from you!