Mild acute cardiac allograft rejection is characterized by
predominantly mononuclear perivascular and/or interstitial
inflammation, that is generally mild, and not associated with
myocyte necrosis. Early after transplantation, the mononuclear
cells may be intermixed with fewer eosinophils and neutrophils.
The key features distinguishing mild, or
IHLTS Grade 1
rejection from moderate, or Grade 2 or 3 rejection, are the
severity of the infiltrate and the presence of myocyte damage.