Maiko Fujii

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.

Non-receptor type, proline-rich protein tyrosine kinase 2 (Pyk2) is a possible therapeutic target for Kawasaki disease

Kawasaki disease (KD) is a paediatric vasculitis whose pathogenesis remains unclear. Based on experimental studies using a mouse model for KD, we report here that proline-rich protein tyrosine kinase 2 (Pyk2) plays a critical role in the onset of KD-like murine vasculitis. The mouse model for KD was prepared by administrating a Candida albicans water-soluble fraction (CAWS). Unlike CAWS-treated WT mice, CAWS-treated Pyk2-Knockout (Pyk2-KO) mice did not develop apparent vasculitis. A sustained increase in MIG/CXCL9 and IP-10/CXCL10, both of which have potent angiostatic activity, was observed in CAWS-treated Pyk2-KO mice. CAWS-induced activation of STAT3, which negatively regulates the expression of these chemokines, was also attenuated in macrophages derived from Pyk2-KO mice. The present study suggests that defects in Pyk2 suppress KD-like experimental vasculitis, presumably through CXCL9- and CXCL10-dependent interference with neo-angiogenesis. Since Pyk2-KO mice show no life-threatening phenotype, Pyk2 may be a promising therapeutic molecular target for KD.

Histopathological Characteristics of Post-inflamed Coronary Arteries in Kawasaki Disease-like Vasculitis of Rabbits

Kawasaki disease (KD) is a systemic vasculitis in infants that develops predominantly in the coronary arteries. Despite the clinically transient nature of active inflammation in childhood albeit rare complications (e.g., coronary artery aneurysm), KD has recently been suggested to increase the incidence of ischemic heart diseases in young adulthood. However, little is known about the histopathology of the coronary artery long after development of the acute KD vasculitis. To address this, we conducted histological studies of rabbit coronary arteries in adolescent phase after induction of the KD-like vasculitis induced by horse serum administration. After a transmural infiltration of inflammatory cells in acute phase at day 7, the artery exhibited a gradual decrease in the number of inflammatory cells and thickening of the intima during the chronic phase up to day 90, where proteoglycans were distinctly accumulated in the intima with abundant involvement of α-smooth muscle actin (α-SMA)-positive cells, most of which accompanied expression of VCAM-1 and NF-κB. Distinct from classical atherosclerosis, inflammatory cells, e.g., macrophages, were barely detected during the chronic phase. These observations indicate that the KD-like coronary arteritis is followed by intimal thickening via accumulation of proteoglycans and proliferation of α-SMA-positive cells, reflecting aberrant coronary artery remodeling.

EXPERIMENTAL IMMUNOHISTOCHEMICAL STUDY ON PERSISTENT VASCULAR REMODELING RELATED TO DEVELOPMENT OF ARTERIOSCLEROSIS OR ATHEROSCLEROSIS IN CHRONIC KAWASAKI DISEASE PATIENTS

Atherosclerotic coronary heart disease has recently emerged as a clinical issue among young individuals with a history of Kawasaki disease (KD), which is a systemic vasculitis unique to children. However, whether or not and how KD promotes atherosclerosis remains unclear. We hypothesized that,

Utility of whole‐blood aggregometry for evaluating anti‐platelet therapy for Kawasaki disease

Anti‐platelet therapy for Kawasaki disease (KD) is often done without monitoring drug efficacy. The aim of this study was to investigate the utility of whole‐blood aggregometry to evaluate the efficacy of anti‐platelet therapy for KD.

P-279 Evaluation of Platelet Activation in Kawasaki Disease by Platelet-Derived Microparticles

retrospectively. Non-responsiveness to IVIG was defined as persistent fever (37.5oC over 1 day) after finishing IVIG. This criterion was met in 38 patients (40%), who were all treated with additional IVIG. WBC, CRP, and sodium concentrations were determined before and within half a day after initial IVIG. Generally, the measurement of these laboratory data has been possible at any time. Results: Multivariate logistic regression analysis selected increased WBC count (p < 0.01), increased CRP (p < 0.05), and low sodium concentration (<135mEq/L, p < 0.01) just after initial IVIG, as independent predictors of non-responsiveness to low-dose IVIG. The criteria for at least one of the three predictors were considered to be useful for detecting non-responsiveness to initial low-dose IVIG for acute KD (Sensitivity = 89%, Specificity = 60%). Conclusion: Using our simple predictive models, we can select non-responder to low-dose IVIG treatment, which decrease a total dosage of IVIG in patients with acute KD.