Working Forumulation ISHLT 1990

          Working Forulation ISHLT 2004

Grade 0 (No Acute Rejection)

Grade 0R (No Acute Cellular Rejection)

Grade 1A (Focal, Mild Acute Rejection)

Grade 1R (Mild, Low-grade, Acute Cellular Rejection) - Interstitial and/or peri-
 vascular infiltrate with up to 1 focus of myocyte damage

Grade 1B (Diffuse, Mild Acute Rejection)

Grade 2 (Focal, Moderate Acute Rejection)

Grade 3A (Multifocal Moderate Rejection)

Grade 2R (Moderate, Intermediate-grade, Acute Cellular Rejection) - Two or more foci of infiltrate with associated myocyte
damage

Grade 3B (Diffuse, Borderline Severe Acute Rejection)

Grade 3R (Severe, High-grade, Acute Cellular Rejection) - Diffuse infiltrate with multifocal myocyte damage ± edema, ± hemorrhage ± vasculitis

Grade 4 (Severe Acute Rejection)