**6.1 Classification of AMR**

pAMR 0 negative for pathologic AMR: histopathologic and immunologic studies are both negatives [3, 6];

pAMR 1 (H+)—histopathologic AMR alone: histopathologic findings present and immunopathologic findings negative;

pAMR 1 (I+)—immunopathologic AMR alone: immunopathologic AMR alone: histopathologic findings negative and immunopathologic findings positive, that is, CD68+ and/or C4d + for IHC and C4d + with or without C3d + for IF.

pAMR 2—pathologic AMR: histopathologic and immunopathologic findings are both present.

pAMR 3 severe pathologic AMR: interstitial hemorrhage, capillary fragmentation, mixed inflammatory infiltrates, endothelial cell pyknosis, and/or karyorrhexis and marked edema and immunopathologic findings are present.
