Regulation of T- and B-cell interactions determines the clinical phenotype associated with donor-specific antibodies

The cellular mechanisms that regulate donor-specific antibody formation and antibody-mediated rejection remain unknown. In this issue, Louis et al. report that specific T-regulatory cell and B-regulatory transitional cell subsets are concomitantly diminished in patients with donor-specific antibody and consequent antibody-mediated rejection and advance alterations in specific cytokines and costimulatory molecules as important mechanisms by which these cells may suppress donor-specific antibody formation and, independently, progression to antibody-mediated rejection.