Background: "Acute tubular necrosis (ATN)-like" changes in type I acute antibody- mediated rejection (AAMR) have been proposed since 2005, but the presence of "ATN-like" injury in AAMR has not well been established. The aim of this study was to confirm the presence of acute tubular injury in type I AAMR, using the specific proximal tubular injury marker, kidney injury molecule-1 (KIM-1).
Design: The study included 3 groups of cases, namely, a negative control group (normal nontransplantation renal parenchyma as group 1, n = 11), a positive control group (transplant ATN with negative C4d staining as group 2, n = 12), and study cases (type 1 AAMR as group 3, n = 19).