No abstract

Background: Matrix metalloproteinases (MMPs) contribute to extracellular remodeling in Kawasaki disease (KD). MMP-9 is an essential vasculature-remodeling factor but its role in the vascular lesions of KD is not understood. This study focused on MMP-9 regulation via cytokines in endothelial cells (ECs). Methods and Results:Plasma and peripheral blood mononuclear cells were obtained from 30 KD patients, and 15 non-febrile and 25 febrile children. Plasma MMP-1, -2, -9, and tissue inhibitor of MMP (TIMP)-1 and -2 were measured by 2-step sandwich ELISA. Immunohistology was performed on coronary arterial lesions (CAL) from a patient who died of KD in the acute phase. MMP-9 mRNA expression in human umbilical ECs (HUVECs) treated with plasma or cytokines, and in mononuclear cells was measured by semi-quantitative reverse transcription-polymerase chain reaction. Plasma MMP-1, -2 and TIMP-2 levels were normal for KD. Plasma MMP-9 and TIMP-1 levels increased during the acute phase of the disease (P<0.001 vs each control). MMP-9 stained diffusely in CAL. MMP-9 mRNA levels were higher in HUVECs treated with plasma in the acute and convalescent phases. Interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α stimulated MMP-9 expression, whereas interferon (IFN)-γ suppressed it. There was no MMP-9 mRNA elevation in mononuclear cells. Conclusions:ECs are a source of MMP-9 in the vascular lesions of KD. MMP-9 is regulated by cytokines IL-1β, IL-6, TNF-α and IFN-γ. (Circ J 2010; 74: 1670 - 1675

The results of this study suggested that HMG-CoA reductase inhibitors are useful as an alternative therapeutic strategy for stabilizing continuous post-inflammatory vascular remodeling that results in the development of arteriosclerosis late after KD or early onset of atherosclerosis in the future.

Acute mitral insufficiency due to the rupture of chordae tendinae from papillary muscles is a rare but sometimes fatal condition in neonates and infants. Here, we report a 21-day-old neonate with sudden onset of mitral insufficiency due to rupture of the chordae tendinae. The baby was successfully rescued by appropriate diagnosis and emergency surgical operation with reconstruction of the ruptured chordae using autologous pericardium-reinforced mattress suture. Intraoperative findings revealed fibrous scar formation at the distal end of the posterior papillary muscle, indicating a remnant of a certain inflammatory reaction. Transplacental passage of maternal anti-SSA antibody could account for the fetal inflammation at the ruptured chordae and the papillary muscle.

No abstract