Graft-versus-host disease (GVHD) is caused by the activity of the donor’s T cells. T cells are a type of white blood cell. The T cells of the donor (graft) react against the cells of the patient (host). Therefore, the condition is called graft (donor)-versus-host(patient) disease.
Accute and chronic GCHD:
+ In general acute GCHD occurs before Day +100 and
+ Chroic GVHD occurs after Day +100.