What is HLA incompatibility?
Introduction. Antibody incompatible transplantation (AiT) is defined as transplantation across an Human Leukocyte Antigen (HLA) antibody barrier, with defined donor-specific antibody being present at the time of transplantation or at the initiation of pre-transplant conditioning.
Why does transplant rejection occur?
Rejection is caused by the immune system identifying the transplant as foreign, triggering a response that will ultimately destroy the transplanted organ or tissue. They are matched based on their blood group, tissue typing, and how the recipient’s blood serum reacts to donor cells.
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.
Can a rejected organ be reused?
Normally if a transplant recipient unexpectedly dies or when the organ is rejected, the donated kidney is discarded. After a kidney is transplanted, scar tissue can form around the organ; that makes reusing it more difficult because the surgeon can’t attach it to vital blood vessels.
When did HLA become a cause of allograft rejection?
By the end of the 1960s, antibodies to HLAs were well recognized as a cause of allograft rejection 9, 10, 11. During the 1970s, the complement-dependent cytotoxicity (CDC) test became standard protocol for determining eligibility for a specific renal allograft (Box 1; Fig. 1a ).
How are non HLA antibodies used in graft screening?
Non-HLA Antibodies reactive with donor endothelial cell antigens have been implicated in rejection and graft loss. The MICA Single Antigen Antibody Screen detects IgG antibodies against the most common MICA alleles and allows high throughput antibody screening and identification using Luminex technology.
How does HLA affect the transplant waiting list?
Pre-transplant sensitization decreases the number of compatible donors and therefore increases transplantation waiting time and the risk of death while on the waiting list. Patients who are not sensitized to HLA molecules can still develop de novo donor-specific antibodies (DSAs) or T cell-mediated rejection after transplantation.
Why are allogeneic HLA antibodies important in transplantation?
Allogeneic HLA-specific antibodies can develop as a result of pregnancy, blood transfusion or transplantation and can result in the rapid rejection of a subsequently transplanted organ or tissue. Thus, detection and avoidance of anti-HLA antibodies was essential to enable meaningful progress in the field of transplantation.