Abstract : The evaluation of anti-HLA immunization in organ transplantation has evolved dramatically since the first lymphocytotoxic crossmatch between donor and recipient was described. The same is true for HLA typing, which can now be performed by high-resolution sequencing. Nevertheless, the transplantation of a totally compatible organ remains an exception and the appearance of anti-HLA antibodies during the transplantation is inevitable, which conditions the long-term survival of the graft. New computer tools are currently being developed to evaluate and quantify the degree of incompatibility between donor and recipient, with a view to predicting the risk of rejection and adapting immunosuppressive therapy in a targeted manner for each patient.