The role of anti-HLA antibodies in renal transplantation

renal transplantation Human leukocyte antigens (HLA) are a highly polymorphic system of glycoproteins that have a functional role in the presentation of peptides to the immune system.1,2 HLA class I molecules are expressed on most nucleated cells, while HLA class II antigens are generally found on professional antigen-presenting cells.3 HLA class II antigens can also be upregulated on kidney cells.4 As a highly polymorphic system, however, specific HLA alleles can become the targets of antibody responses in people sensitised to foreign HLA molecules during pregnancy, transfusion of blood products, or organ transplantation.1,5,6 Humoral responses or sensitisation to HLA are major barriers to solid organ transplantation.1,7 Sensitised patients are more likely to crossmatch positive with potential donors and have a reduced chance of receiving a renal transplant.8 The detection of anti-HLA antibodies helps to predict both the function and survival of transplant allografts.9 Most allograft damage is mediated though the activation of complement; C4d deposition is widely accepted as a marker for antibody-mediated rejection in renal allografts.10