Cellular Infiltration of the Human Arterial Adventitia Associated with Atheromatous Plaques

Homogeneous collections of cells resembling small lymphocytes have been found in the adventitia of atheromatous arteries, and the prevalence and degree of cellular infiltration have been shown to correlate closely with the severity of the plaques. The cells are found in the aorta, coronary, iliac, and carotid arteries; but in the carotid arteries the infiltration is less marked. Arterial blocks containing recent thrombus show more cellular infiltration than blocks without thrombus and with recanalizing thrombus. The location and significance of the adventitial cellular infiltration is unknown, but it may play a part in the etiology or pathogenesis of arterial plaques.