Significance of anti-HLA and donor-specific antibodies in long-term renal graft survival.

Numerous studies have demonstrated an association of posttransplant HLA antibodies with decreased long-term graft survival. The presence of C4d deposition in these cases supports the hypothesis that antibody and complement deposition are involved in the pathogenesis of graft failure. Development of HLA antibodies may predate the clinical manifestation of chronic rejection (CR). However, frequency of donor-specific antibody is low when all patients are screened regardless of their graft function, and it may be more valuable to look for antibody only in patients with mild dysfunction. Effective treatment for CR has not been identified, although increased immunosuppression has been shown to decrease antibody levels and stabilize graft function. Many patients have been identified with good graft function despite the presence of circulating donor-specific HLA antibody. Additional studies focusing on the mechanism behind the apparent protection from the detrimental effects of antibody in such patients are needed.