Fig. 5

Histopathology of Rhesus monkey lungs showed no findings attributable to CDP7657. Representative hematoxylin and eosin stained sections of pulmonary arteries/arterioles from Rhesus monkeys that received hu5c8 (a-b), vehicle control (c) or CDP7657 (d). In a and b arterial thrombus formation is accompanied by marked, irregular thickening of the intimal layer (arrows). Intimal thickening is mediated by in-migration of smooth muscle, deposition of pale basophilic fibrillar extracellular matrix and cleft formation. Vessel lumina contain fibrinocellular debris and entrapped red blood cells. In c and d fibrin microthrombi adhere to the endothelial lining of thin-walled arterioles (arrows). Under normal conditions, microthrombi are formed and lysed continually within the venous circulatory system. Small pulmonary arterial vessels and capillaries trap thrombi and prevent them from obstructing the vital coronary, cerebral and renal arteries. These observations were isolated, infrequent findings