Humoral effectors and cellular targets of chronic-allo rejection in the arterial wall

Contrasting with acute rejection, chronic rejection of arterial allograft d on't involve leukocyte passengers from the graft to the host. Chronic rejec tion involves the proteins of the major hiscompatibility complexes. Experim ental studies in rats shelved that the process evolved in three stages : a first stage of histo-incompatibility recognition mediated by the graft endo thelium, a second stage of immune antibody-dependent injury of allogenic sm ooth muscle cells of the media associated with inflammatory infiltration of the adventitia, lastly a third stage of scarring process including intimal proliferation and adventitial fibrosis.