HLA antibody testing: a tool to facilitate not to prevent organ transplantation.

The introduction of very sensitive HLA antibody screening assays has destroyed the old dogma that pre-existence of donor specific HLA antibodies in the patient is a contra-indication for transplantation. The challenge is now to reach consensus on the parameters which predict the clinical relevance of donor specific HLA antibodies. Antibody screening assays should not only be used to prevent transplantation of patients with donor specific antibodies but also to facilitate transplantation of highly sensitized patients, both by defining acceptable HLA mismatches and non-detrimental donor specific HLA antibodies.