**6.2 Classification of acute cellular rejection (ISHLT)**

Grade 0—no rejection [7].

Grade 1R, mild—interstitial and/or perivascular infiltrate with up to one focus of myocyte damage.

Grade 2R, moderate—two or more foci of infiltrate with associated myocyte damage.

Grade 3R, severe—diffuse infiltrate with multifocal myocyte damage, with or without edema, hemorrhage, or vasculitis.
