Fatal cardiac dysfunction in a child with Williams syndrome.

Williams syndrome (WS) is a rare genetic disorder caused by a microdeletion of chromosome 7q11.23. Although the mortality rate of patients with WS is not very high, sudden cardiac death can occur, particularly in cases complicated by coronary artery stenosis. A 3-month-old female infant with supravalvular aortic stenosis and peripheral pulmonary stenosis was discovered unconscious in bed by her mother. She was immediately transferred to an emergency hospital but succumbed despite multiple attempts as resuscitation. DNA microarray analysis revealed microdeletions of 7q11.23 and 16p11.2, confirming WS and unexpectedly identifying 16p11.2 deletion syndrome which is known to be associated with neurodevelopmental disorders. Postmortem computed tomography revealed a severely enlarged heart, indicative of cardiac dysfunction. External examination revealed moderate-to-severe developmental delays in height and body weight. The heart, on internal examination, revealed whitish-discolored lesions; histologically severe fibrotic changes and thickening of the intima in the coronary arteries and aorta. In the brain, the dentate gyrus of the hippocampus appeared malformed. Taken together, these findings suggest that the cause of death was cardiac dysfunction due to WS. In addition, it could be possible that 16p11.2 deletion syndrome and dentate gyrus malformation contributed to her death. Future autopsy studies are warranted to clarify the precise role of microdeletion disorders in sudden death to reduce future preventable deaths in children.

Changes in cerebral oxygen saturation and blood flow during hypoxic gas ventilation therapy in HLHS and CoA/IAA complex with markedly increased pulmonary blood flow.

BACKGROUND: Hypoxic gas ventilation therapy has recently been performed to prevent post-birth increased pulmonary blood flow in cases of congenital heart diseases with increased pulmonary blood flow. However, how the oxygen supply to the tissues changes during breathing a hypoxic gas mixture, remains unknown. The changes in cerebral oxygen saturation and blood supply during hypoxic gas ventilation therapy using a nitrogen gas mixture were studied. METHODS AND RESULTS: Cerebral regional oxygen saturation (cerebral rSO(2)) was measured by near-infrared spectroscopy, and changes in middle cerebral artery (MCA) blood flow and an index of vascular resistance (RI) were assessed in 8 consecutive patients having congenital heart diseases with increased pulmonary blood flow. In all patients, urinary volume increased significantly, and the respiratory rate showed a clear decrease. Percutaneous oxygen saturation showed no significant change. The average of cerebral rSO(2) was 67.3% before hypoxic gas ventilation, but increased to 69.4%, 69.1%, and 70.7% within 1, 12, and 24 h after initiation of treatment, respectively. MCA blood flow significantly increased in the diastolic phase, and RI significantly improved from 0.80 to 0.68 within 12 h after initiation of therapy. CONCLUSIONS: These results indicate that hypoxic gas ventilation therapy does not decrease cerebral oxygen saturation, but safely improves the cerebral blood supply in cases of congenital heart diseases with increased pulmonary blood flow.

Matrix metalloproteinase-9 in vascular lesions and endothelial regulation in Kawasaki disease.

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)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha stimulated MMP-9 expression, whereas interferon (IFN)-gamma 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-1beta, IL-6, TNF-alpha and IFN-gamma.

Neutropenia in the acute phase of Kawasaki disease and prevention of coronary artery aneurysm.

BACKGROUND: The significance of neutropenia in Kawasaki disease (KD) has not been fully elucidated as yet. METHODS: Subjects were retrospectively sampled from two clinical trials. These patients treated with aspirin alone (ASA) and PolyglobinN-Bayel (PolyN) given as i.v. immunoglobulin were categorized as ASA-early (n = 0), ASA-late (n = 8), PolyN-early (n = 18), or PolyN-late (n = 27) based on the therapy administered and the incidence of neutropenia before the 10th day of illness (DI) and after 11 DI. Data regarding the time of onset of neutropenia, and incidence of coronary artery lesion (CAL) formation were obtained. P < 0.05 was considered statistically significant. RESULTS: No patients in the ASA group exhibited neutropenia within 10 DI. The time of onset of neutropenia in the PolyN-early group was 8 +/- 1.3 DI. That in the PolyN-late group (19.8 +/- 8 DI) was earlier than in the ASA-late group (26.6 +/- 14 DI; P < 0.025). PolyN-early patients had a lower incidence of CAL formation than ASA-non patients (patients without neutropenia in the ASA group; P = 0.00019) and ASA-late patients (P = 0.04). That in the PolyN-early group tended to be lower than in the PolyN-late group (P < 0.1). CONCLUSION: Early neutropenia indicated that circulating neutrophils within 10 DI may play an indispensable role in the following sequence to CAL formation in KD.

[Kawasaki disease and atherosclerosis].

The existence of endothelial damage in impaired coronary arteries, both aneurysms and regressed aneurysms, even during the chronic stage of Kawasaki disease (KD) has been reported by morphologic and functional studies. In addition, based on our results of endothelial-dependent dilatation in systemic arteries or the pathological findings in weaning rabbits in the chronic stage of KD-like allergic coronary arteritis by administering a hypercholesterol diet, it is suggested that vascular endothelial dysfunction, not only in coronary arteries but also in systemic arteries, could exist in the KD patients even in a chronic stage, and also suggested that a history of KD was possible to be one of the risk factor for the early onset of atherosclerosis.

The role of apelin on the alleviative effect of Angiotensin receptor blocker in unilateral ureteral obstruction-induced renal fibrosis.

BACKGROUND: Apelin is a selective endogenous ligand of the APJ receptor, which genetically has closest identity to the angiotensin II type 1 receptor (AT-1). The effects of the apelin/APJ system on renal fibrosis still remain unclear. METHODS: We examined the effects of the apelin/APJ system on renal fibrosis during AT-1 blockade in a mouse unilateral ureteral obstruction (UUO) model. RESULTS: WE OBTAINED THE FOLLOWING RESULTS: (1) At UUO day 7, mRNA expressions of apelin/APJ and phosphorylations of Akt/endothelial nitric oxide synthase (eNOS) in the UUO kidney were increased compared to those in the nonobstructed kidney. (2) AT-1 blockade by the treatment with losartan resulted in a further increase of apelin mRNA as well as phosphorylations of Akt/eNOS proteins, and this was accompanied by alleviated renal interstitial fibrosis, decreased myofibroblast accumulation, and a decreased number of interstitial macrophages. (3) Blockade of the APJ receptor by the treatment with F13A during losartan administration completely abrogated the effects of losartan in the activation of the Akt/eNOS pathway and the amelioration of renal fibrosis. (4) Inhibition of NOS by the treatment with L-NAME also resulted in a further increase in renal fibrosis compared to the control group. CONCLUSION: These results suggest that increased nitric oxide production through the apelin/APJ/Akt/eNOS pathway may, at least in part, contribute to the alleviative effect of losartan in UUO-induced renal fibrosis.

Effects of HMG-CoA reductase inhibitors on continuous post-inflammatory vascular remodeling late after Kawasaki disease.

BACKGROUND: In Kawasaki disease (KD), it has been clinically and experimentally reported that post-inflammatory vascular remodeling would induce the development of arteriosclerosis or early onset of atherosclerosis in the future. The effects of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors on continuous vascular remodeling late after Kawasaki disease were clinically evaluated. PATIENTS AND METHODS: We enrolled and treated a total of 11 KD patients (age range, 7-25 years) with fluvastatin (0.5-0.7 mg/kg/day) for 12 months. All of them had significant coronary aneurysmal or stenotic lesions and more than 3 of the following 5 abnormal findings: reduced %flow-mediated dilatation (%FMD), reduced urinary NOx, elevated high-sensitivity C-reactive protein (hs-CRP), reduced urinary 8-isoprostane, and elevated brachial-ankle pulse wave velocity (baPWV; control, ≤1400 cm/s). RESULTS: A statistically significant improvement was observed in each biomarker after fluvastatin treatment: %FMD, from 9.29% (3.41)% to 10.55% (3.27)% (p=0.003) after 3 months; NOx/creatinine (cre), from 1.16 (0.54) µmol/mg cre to 1.30 (0.50) µmol/mg cre (p=0.038) after 12 months; baPWV, from 1175.4 (277.3) cm/s to 1031.8 (155.6) cm/s (p=0.009) after 3 months; hs-CRP, from 0.073 (0.035) mg/dl to 0.028 (0.014) mg/dl (p=0.0002) after 3 months; and 8-iso/cre, from 751.8 (241.8) pg/mg cre to 660.0 (198.5) pg/mg cre (p=0.018) after 3 months. No adverse events were clinically observed in the patients. CONCLUSIONS: 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.

Linear shadows inside coronary arterial lesions on two-dimensional echocardiograhpy in Kawasaki disease patients.

BACKGROUND: Conventional two-dimensional echocardiography (2DE) is not adequately sensitive enough for the detection of stenotic or occlusive coronary lesions that occur in Kawasaki disease. Recently, linear shadows have been detected inside large- or moderate-sized coronary artery lesions (CALs) by high-resolution 2DE at a convalescent or chronic stage. PURPOSE AND METHODS: We evaluated the clinical significance of the linear shadows detected by 2DE and compared the findings with those obtained using coronary angiography (CAG), magnetic resonance imaging (MRI), and intravascular ultrasound (IVUS). RESULTS: From December 2001 to November 2006, linear shadows were detected in 11 out of 18 CALs in 9 patients at our institution. The outer diameters of the CALs by 2DE were larger than the diameters of CALs by CAG, while the inner diameters between the linear shadows by 2DE correlate with the diameters of CALs by CAG. Remarkably thickened intima was confirmed in 7 out of 9 CALs by MRI, and in every lesion that was examined using IVUS. CONCLUSIONS: The results of this study suggest that linear shadows by 2DE would indicate the existence of a thickened intima. We consider that linear shadows may be useful to estimate the development of stenotic lesions during the process of regression or remodeling of CALs.

MMP-2 inhibition reduces renal macrophage infiltration with increased fibrosis in UUO.

We examined the role of matrix metalloproteinase-2 (MMP-2) in renal fibrosis and its effect on interstitial macrophage infiltration in a mouse model of unilateral ureteral obstruction (UUO). TISAM, a selective inhibitor of MMP-2, was administered during early stage (day -2 to 4; protocol A) and late stage (day 7 to 13; protocol B) after UUO. Treatment with TISAM accelerated fibrosis both at day 5 (A) and at day 14 (B). The degree of macrophage infiltration was decreased by the treatment with TISAM at day 14, but not at day 5. In vitro macrophage migration assay showed a greater migration to renal tissue of control UUO kidney (day 14) than to TISAM-treated kidney, which was suppressed by preincubating macrophages with RGDS, a fibronectin degradation peptide. These results suggest that MMP-2 acts to accelerate macrophage infiltration in the late stage of UUO, possibly by degrading extracellular matrix components.

A randomized prospective study on the use of 2 g-IVIG or 1 g-IVIG as therapy for Kawasaki disease.

A single, 2 g/kg dose of immune globulin (IG), denoted 2 g-intravenous (IV)IG, has become a standard regimen for treating Kawasaki disease (KD) because of its highly preventive effect on coronary arterial lesions (CAL). However, IG is obtained from blood specimens, a drawback to many patients, and is also very expensive. This randomized prospective study reported here was carried out with the aim of developing a treatment regimen that would reduce the total dose of IG. The study tested two protocols (A: 2 g-IVIG; B: 1 g-IVIG) that included the strategy of administering additional IVIG to IVIG-resistant patients based on the criteria we described previously. In protocol A, an additional 2 g-IVIG was administered only once; in protocol B, the first additional IVIG was 1 g-IVIG and the second was 2 g-IVIG. One hundred and nine patients who were admitted before the seventh day of illness and had no CAL at the time of admission were enrolled in the study (protocol A: 54 patients; B: 55 patients). In the protocol A group, 7.4% (4/54) of the patients received 4 g/kg IG. In protocol B, 41.8% (23/55) were treated only with 1 g/kg IG, and 10.9% (6/55) received 4 g/kg IG. No significant differences were observed between the patients of the two subgroups receiving 4 g/kg IG in each protocol group. Discriminate analysis also suggested that 52.4% of the patients in the protocol A group could be treated only with 1 g/kg IG. On the other hand, no significant difference was observed in the incidence of aneurysms between patients in the protocol A group (1/54) and those in the protocol B group (4/55). Our protocol based on 1 g-IVIG, including additional IVIG, was assessed to be an effective treatment and to provide a considerably useful means to reduce the total dose of IG.

Long-term changes in coronary artery aneurysms in patients with Kawasaki disease: comparison of therapeutic regimens.

BACKGROUND: There are few studies of the therapeutic regimens for the prevention of stenotic transformation of aneurysms in Kawasaki disease (KD). The aim of this study was to assess the prophylactic effect of combined therapy in the acute stage and convalescent- to chronic-stage against the formation of stenotic lesions. METHODS AND RESULTS: In 85 patients, 103 giant aneurysms (ANl), 46 medium-sized aneurysms (ANm), and 13 small aneurysms (ANs) were analyzed. With respect to therapy in the acute stage, no localized stenosis of ANl in the left coronary artery was noted in patients who received high-dose gamma globulin therapy (G). For ANm, the group (G) showed a significantly higher regression rate than the aspirin group and steroids group. Furthermore, no coronary artery occlusion/recanalization of ANl occurred with the prophylactic regimen of aspirin and warfarin {aw}. Prophylaxis {aw} and the prophylactic regimen of aspirin alone {a} significantly lowered the incidence compared with either the prophylactic regimen of warfarin {w} or no prophylaxis {n}. However, no significant differences were noted between prophylaxis {w} and {n}. CONCLUSIONS: High-dose gamma globulin therapy in the acute stage of KD is the first choice for the prevention of stenotic transformation. Prophylaxis {aw} is recommended for ANl.