HLA or Human Leukocyte Antigen is a process through which antibodies are detected before any organ or bone marrow transplantation. In other words, it can be explained as an essential procedure to compare the tissues of both the donor and the recipient post transplantation. HLA can also be termed as a defence system against diseases and in many cases it plays a major role in the rejection of organs or bone marrow after transplantation. The immune system in human body has a very large number of genes that aids in the function of the immune system. Since, it is difficult to detect identical molecules of HLA in two individuals, transplantation becomes almost impossible. HLA identification and matching is compulsory for organ transplantation between two individuals.
HLA typing can be a really time consuming process and is also very much expensive with very less possibilities in discriminating the alleles at a very High-Resolution level. The NGS or Next Generation Sequencing is proven to be very effectively testing the HLA. The process is normally done for exon 2 and 3 of HLA-A and HLA-B and in most of the cases samples from two individuals are analysed as HLA-A, B and C and HLA-DQB1 and running the same in one sequence with 2 x 300 bp. This process is very much cost effective compared to earlier versions of testing.
The most basic uses of HLA or Human Leukocyte Antigen Typing is to check if the Recipients and the Donor's blood matches the requirement of the Recipient’s Immune system is friendly or rejects the donated organ, bone marrow or cord blood transplanted. It is also used most commonly to identify the most important Genes of HLA in a person which he/she has inherited and if the antigens or more commonly known as proteins are present in the cells or not.
In HLA high resolution typing which also known as Human Leukocyte Antigen is done through HLA A and B, HLA-DR and HLADQ antigens and this process is followed with the mentioned antigens for the purpose of Organ transplantation and Bone Marrow. Most important is the tissue typing which is meant to detect the presence the any antibodies against the antigens of the HLA. In case if any antibody is detected in the antigens it will result in binding with the cells. In other words it is to detect antigens on the WBC or White Blood Cells and is most commonly known as histocompatibility testing.