Immunoglobulin deposition in atherosclerotic aortocoronary saphenous vein grafts

Aortocoronary saphenous vein grafts develop a rapidly progressive atherosclerosis that is diffuse, concentric, and histologically distinct from that in native coronary arteries. To explore a possible role of immunologic injury in this form of atherosclerosis, frozen sections of saphenous vein grafts and normal saphenous vein controls were examined for deposits of immunoglobulins, C3, and fibrinogen by direct immunofluorescence. Immunoglobulins were found in 19 of 24 grafts, all with diffuse concentric intimal fibroplasia or atherosclerosis. No immunoglobulins were found in 5 grafts with focal eccentric atherosclerosis or organized thrombi or in the five controls. C3 and fibrinogen were also found in the majority of grafts and controls. Immunoglobulins were distributed concentrically throughout the intima or associated with atheromatous debris. The amount of immunoglobulin correlated with the amount of atheromatous debris.