[Post-transplantation anti-HLA antibodies: which relevance?]

Anti-HLA antibodies formed de novo post-transplantation are involved in the development of acute humoral rejection also known as antibody-mediated rejection. This form of rejection is characterized by histological lesions, a positive C4d-staining of peritubular capillaries and anti-donor antibodies. The presence of anti-HLA antibodies indicates a poor prognosis as it is associated with a highly significant increase of graft loss risk, which might depend on antibody concentration. To prevent acute humoral rejection, antibodies must be systematically detected 3 months after transplantation with sensitive methods using recombinant HLA antigens that allow detecting anti-HLA antibodies by ELISA, flow cytometric panel-reactive antibodies test or immunobead flow cytometric assay, the intensity of fluorescence determining the concentration of anti-HLA antibodies. In case of acute graft dysfunction, antibody-mediated rejection must be treated by a combination of immunosuppressive drugs, antibodies, intra-venous immunoglobulins and/or plasmaphereses.