CORONARY-ARTERY ANEURYSMS DEVELOP IN WEANLING RABBITS WITH SERUM SICKNESS BUT NOT IN MATURE RABBITS - AN EXPERIMENTAL-MODEL FOR KAWASAKI-DISEASE IN HUMANS

The involvement of the cardiovascular system in rabbits with serum sic kness is similar of that in Kawasaki disease, both with respect to the histologic changes of the myocardium, the valves, the coronary arteri es, and the aorta and to the sequence with which they appear. Although coronary arteritis appears the same histologically, aneurysms did not occur in mature rabbits, even in case of necrosis of an arterial segm ent with deletion of muscle and elastic tissue. On the other hand, wea nling rabbits with serum sickness had a tendency to develop aneurysms of coronary arteries, despite little cellular infiltration and reactiv e fibrocellular hyperplasia. The age factor thus appears to play an im portant role in the development of coronary aneurysms in Kawasaki dise ase, irrespective of the underlying mechanism, be it a markedly increa sed permeability to mediators through degenerated endothelial cells, o r primary degenerated muscle cells with marked thinning of the media w ithout much inflammatory cellular reaction. Furthermore, this study pr ovides an insight into the long-term prognosis of transient dilatation of coronary arteries in the acute stage of Kawasaki disease.