What is HLA crossmatch?

What is a crossmatch? The crossmatch is thought to be a miniature test transplant performed in the laboratory. To complete this test a sample of blood is taken from the donor and recipient. The blood must be drawn at the same time. In the laboratory, the donor blood cells are mixed with the recipient serum.

What are cross reactive epitope groups?

Some polymorphisms on HLA molecules are shared by different HLA types, which allows us to group HLA molecules into ‘families’ or groups based on the shared epitope. These cross-reactive epitope groups (CREGs) can be used as a basis for matching donors to recipients for renal transplantation.

Are there different types of HLA antibodies?

There are three general groups of HLA, they are HLA-A,HLA-B and HLA-DR. There are many different specific HLA proteins within each of these three groups. (For example, there are 59 different HLA-A proteins, 118 different HLA-B and 124 different HLA-DR!)

What is Flow crossmatch?

The flow cytometric lymphocyte crossmatch is a standard technique for evaluating the compatibility of potential kidney transplant recipients and donors. Recipient serum is incubated with donor lymphocytes and the latter are analysed in a flow cytometer for the presence of bound IgG antibodies.

What is HLA matchmaker?

Background: HLA Matchmaker is a computer algorithm developed to evaluate donor/receptor compatibility comparing sequences of polymorphic aminoacids (eplets) present in human leukocyte antigen (HLA) molecules.

What are private epitopes?

Epitopes are present on a single HLA (private epitope) or shared by multiple antigens (public epitope). The phenomenon of cross-reactivity in HLA testing, often explained as cross-reactive groups (CREGs) of antigens with antibody, can be clearly explained now by public epitopes.

What are HLA class 1 and 2 antibodies?

HLA class I molecules are expressed on the surface of almost all nucleated cells. Class II molecules are expressed only on B lymphocytes, antigen-presenting cells (monocytes, macrophages, and dendritic cells), and activated T lymphocytes.

Which dye is used in HLA typing?

If the antibodies recognize their epitope on the donor’s HLA then complement activation occurs leads to cell lysis and death, allowing the cells to take up a dye (trypan blue). This allows for identification of the cells’ HLA based indirectly on the specificity of the known antibodies in the serum.

How is a cross matching test similar to a blood typing test?

Blood typing focuses on the antigens on the surface of the red cell. Crossmatching focuses on antibodies in the plasma. In a crossmatch, donor red cells are mixed with the plasma of the recipient.

How do I interpret HLA typing results?

The typing result of the recipient is compared to those of the potential donor. Results indicate how many antigens match and how many antigen mismatches are present. “0 mismatches” indicates a high probability that the organ or tissue will not be rejected by the recipient.