LAUSR

T pathogenic role of non-HLA antibodies in antibodymediated rejection (AMR) has been increasingly recognized, with inclusion in the Banff 2017 classification.1 While several non-HLA antibodies have been implicated, it is clear there are additional uncharacterized non-HLA antigenic targets.2 The minor histocompatibility antigens in the Kidd blood group system were first described in the 1950s,3,4 and subsequent reports suggested that antibodies against Jka and Jkb antigens can potentiate renal transplant rejection.5-10 Jka and Jkb are codominant alleles encoding a glycoprotein urea transporter expressed on the surface of red blood cells (RBCs), renal endothelium of the vasa recta, and tubular epithelial cells,7,11,12 providing a plausible pathophysiological mechanism for Kidd-mediated AMR. We report a case of hyperacute rejection that we believe is best explained by preformed donor-specific anti-Jka antibodies. CASE DESCRIPTION