2004 | Grade 0 R¶ | No rejection | Grade 1 R, mild | Interstitial and/or perivascular infiltrate with up to 1 focus of myocyte damage | Grade 2 R, moderate | 2 or more foci of infiltrate with associated myocyte damage | Grade 3 R, severe | Diffuse infiltrate with multifocal myocyte damage ± edema, ± hemorrhage ± vasculitis | | 1990 | Grade 0 | No rejection | Grade 1, mild | A - Focal | Focal perivascular and/or interstitial infiltrate without myocyte damage | B - Diffuse | Diffuse infiltrate without myocyte damage | Grade 2 moderate (focal) | 1 focus of infiltrate with associated myocyte damage | Grade 3, moderate | A - Focal | Multifocal infiltrate with myocyte damage | B - Diffuse | Diffuse infiltrate with myocyte damage | Grade 4, severe | Diffuse, polymorphous infiltrate with extensive myocyte damage ± edema, ± hemorrhage + vasculitis | |