Abstract
Kawasaki disease affects children under four years of age and is an acute inflammatory disease with systemic vasculitis. Kawasaki disease is associated with a high incidence of cardiovascular complications such as thrombotic occlusion and aneurysm of the coronary arteries. Thromboxane A2 has the action of vasoconstriction, and increases platelet aggregability. Thromboxane A2 is readily metabolized to the inactive thromboxane B2. The authors measured the levels of plasma thromboxane B2 in the initial stage of Kawasaki disease. Plasma thromboxane B2 level in nomal subjects was 0.28±0.19ng/ml (mean±SD; n=10). Plasma thromboxane B2 level in patients with Kawasaki disease before treatment, was 0.33±0.21ng/ml (mean±SD; n=27). Patients with coronary aneurysm had markedly increased plasma thromboxane B2 levels (2.02±0.84ng/ml; n=7). Elevation of plasma thromboxane B2 levels indicates that there is the possibility of endothelial injury and aneurysm formation.
It is possible that the endothelial injury caused by angitis in Kawasaki disease leads to cardiovascular complications and juvenile atherosclerosis. We measured the serum elastase activity which has antiarteriosclerotic action and its beneficial effect on cholesterol and lipoprotein. We measured the serum elastase activity in nineteen patients with Kawasaki disease during twenty-eight days after the onset of illness. The enzyme activity was measured by the spectrophotometric measurement of elastase using succinyl-trialanyl-p-nitroanilide as a substrate, and by the immunoreactivity Elastase-I RIA kit (Dainabot).
Patients were classified into two types which were based on enzyme activity; namely, one type with increasing serum elastase activity, another type with decreasing serum elastase activity with the passage of time. The latter type tended to the development of coronary aneurysm.
These results suggested that the cases of decreasing serum elastase activity were associated with vascular wall weakness and abnormal lipid metabolism in Kawasaki disease.
