Posttransplant Human Leukocyte Antigen Antibodies in Stable Kidney Transplant Recipients.

Detection of donor-specific antibodies represents a major criterion of antibody-mediated rejection. This type of rejection, a leading cause of long-term allograft failure, may be the consequence of a multistep process initiated by the formation of donor-specific antibodies, which may subsequently trigger microcirculation inflammation and tissue damage followed by graft dysfunction and loss. At first sight this concept is in strong support of implementing a per-protocol longitudinal antibody monitoring in all kidney transplant recipients. One may speculate that early detection of donor-specific antibody occurrence could guide timely anti-humoral treatment, preventing subsequent irreversible graft damage. However, recent studies have revealed controversial results. In contrast to recipients with graft dysfunction, a considerable proportion of patients with normal function at the time of antibody testing were shown to maintain excellent long-term survival despite detectable de novo donor-specific antibodies. Moreover, the persistence of detectable antibodies following desensitization in immunological high-risk patients was described to be not necessarily associated with inferior transplant performance. For donor-specific antibody positive stable patients, a role of transplant accommodation, a state of acquired resistance to immune injury, was speculated. The present review focuses on the still controversial issue of donor-specific antibody monitoring in kidney transplant recipients, putting a special focus on stable patients who present without clinical signs of ongoing rejection. [ABSTRACT FROM AUTHOR]