Kawasaki Disease (KD) is a childhood disease leading to coronary arteritis. Elevated numbers of CD40L+ platelets in circulation is correlated with risk of heart damage. CD40L is a tumor necrosis family member that binds to CD40 and αIIbβ3, receptors which are also expressed on platelets. A single injection of Lactobacillus casei Cell Wall Extract (LCWE) induces a disease similar to KD in mice, where LCWE superantigen (SAg) reactive T-cells persist in the coronary artery. This phenotype is inconsistent with the fate of SAg-stimulated cells and is likely mediated by co-stimulation. This work shows that stimulation with a SAg induces platelet activation and CD40L expression in vitro. Furthermore, enhanced survival of SAg-reactive T-cells is demonstrated following antibody-mediated CD40L cross-linking. This effect is mediated via inhibition of the extrinsic apoptosis pathway. In addition, CD40 cross-linking is also reported to enhance SAg-reactive T-cell survival by enhancing CD86 expression on APCs and CD28 co-stimulation.

Kawasaki Disease (KD) is a childhood disease leading to coronary arteritis. Elevated numbers of CD40L+ platelets in circulation is correlated with risk of heart damage. CD40L is a tumor necrosis family member that binds to CD40 and αIIbβ3, receptors which are also expressed on platelets. A single injection of Lactobacillus casei Cell Wall Extract (LCWE) induces a disease similar to KD in mice, where LCWE superantigen (SAg) reactive T-cells persist in the coronary artery. This phenotype is inconsistent with the fate of SAg-stimulated cells and is likely mediated by co-stimulation. This work shows that stimulation with a SAg induces platelet activation and CD40L expression in vitro. Furthermore, enhanced survival of SAg-reactive T-cells is demonstrated following antibody-mediated CD40L cross-linking. This effect is mediated via inhibition of the extrinsic apoptosis pathway. In addition, CD40 cross-linking is also reported to enhance SAg-reactive T-cell survival by enhancing CD86 expression on APCs and CD28 co-stimulation.

Kawasaki disease (KD) is a multisystem vasculitis that results in localized coronary artery elastin breakdown and aneurysm formation. It is the leading cause of acquired heart disease of children in North America. Despite conventional treatment, a significant proportion of patients continue to develop coronary sequelae. The mechanisms of arterial aneurysm formation in KD are not known. Using a murine model of KD, Lactobacillus casei cell wall extract-induced coronary arteritis, the processes leading to coronary aneurysm formation were examined. Vessel damage occurred as a result of the increased enzymatic activity of the elastase, matrix metalloproteinase (MMP)-9. MMP-9 protein and activity levels were elevated in the heart post-disease induction. Expression and activity were specific for and localized to inflamed coronary arteries. The pro-inflammatory cytokine, tumour necrosis factor (TNF)-α, was required for increasing local MMP-9 expression. Importantly, MMP-9-deficient animals had a significantly reduced incidence of elastin breakdown. Furthermore, in a cohort of KD patients, serum MMP-9 did not correlate with coronary outcome, highlighting the importance of local expression of this elastase. Intravenous immunoglobulin (IVIG) and aspirin/salicylate are therapeutic agents in current use for the treatment of KD, though their exact mechanisms of action in KD are not known. The biologic effects of IVIG and salicylate on critical stages of disease development were examined. IVIG and salicylate had differential effects on TNF-α expression, with therapeutic concentrations of IVIG inhibiting, and salicylate inducing, TNF-α expression leading to an indirect modulation of MMP-9 expression. Interestingly, TNF-α expression and MMP-9 activity were both directly inhibited by the metal-chelating drug doxycycline. Treatment of affected mice with doxycycline significantly improved coronary outcome. Inhibiting both the inflammatory response as well as the downstream effects of inflammation were of therapeutic value in this model of KD. These results taken together demonstrate the importance of MMP-9 in the pathogenesis of coronary artery aneurysms in KD. Targeting MMP activity holds the promise of transforming KD from the leading cause of acquired heart disease to a self-limited febrile illness.

Presentation: A 3 month-old male is referred for admission with a 2-day history of fever, having been diagnosed with pneumonia and prescribed a cephalosporin on the previous day. A blood culture obtained at that time is positive for coagulase negative Staphyloccocus. On exam, he is ill-appearing. He has bilateral conjunctivitis that spares the limbus, non-exudative pharyngitis, and a polymorphic truncal rash. There is no appreciable cervical lymphadenopathy or extremity involvement. A chest x-ray demonstrates a round infiltrate of the left upper lobe, and initial labs reveal a white blood count of 17.5, a C-reactive protein (CRP) of 23.9 mg/dL, and a normal comprehensive metabolic panel. His positive blood culture is deemed a contaminant, and antibiotic coverage for community-acquired pneumonia is given with ampicillin. Diagnostic evaluation: On day 5 of illness, his fevers persist despite broadened antibiotic coverage. Further work-up has ruled out viral respiratory pathogens and Epstein-Barr virus as a cause of persistent fevers. Incomplete Kawasaki disease is suspected due to continued fevers, the presence of three clinical criteria, and further increase in his CRP. He lacks other supplemental laboratory criteria, so an echocardiogram is obtained that shows mild dilation of the left anterior descending artery (LAD) of indeterminate significance. A repeat echocardiogram 2 days later reveals progressive dilation of left main coronary artery (LMCA), LAD, and right coronary artery (RCA). Diagnosis: Dilation of the LAD and RCA confirm a diagnosis of incomplete Kawasaki disease. Within 48 hours of treatment with IVIG and high-dose aspirin, the patient is afebrile with resolving symptoms and a declining CRP. He is discharged on the 9th day of illness on low dose aspirin and a cephalosporin to complete an antibiotic course for concurrent pneumonia. Conclusion & Discussion: This case illustrates the importance of maintaining a high index of suspicion for an incomplete presentation of Kawasaki disease, particularly among infants. The American Heart Association’s guidelines were updated in 2017 to improve recognition of incomplete Kawasaki disease, particularly among infants who are more likely to have an incomplete presentation, abnormalities of the coronary arteries, and a delayed diagnosis. The key to this patient’s diagnosis was the presence of a bilateral conjunctivitis that spared the limbus. A bilateral, non-exudative conjunctivitis that spares the limbus has been recognized as a feature suggestive of Kawasaki disease for the better part of four decades; our review of the literature suggests this feature is highly specific to the diagnosis of Kawasaki disease.

Nesta dissertação, estudou-se um modelo tipo gás de rede em três dimensões para simular sistemas líquidos macroscópicos. Aplicou-se o modelo para o estudo das energias e forças envolvidas durante o processo de formação e ruptura de pontes líquidas entre duas placas planas. Esse estudo foi motivado por processos fisiológicos que acontecem no interior dos pulmões dos mamíferos. Além disso, foi feito um estudo das propriedades termodinâmicas do modelo. Com relação a aplicação fisiológica, observou-se que, no processo da formação da ponte líquida, a energia livre da ponte líquida é menor que a energia livre da gota, para diferentes sistemas líquidos. Com este resultado, fez a hipótese de que parte dessa energia é dissipada na forma de energia acústica. A emissão do som também deve ocorrer na ruptura da ponte líquida. Comparando a energia livre no processo de formação e ruptura da ponte líquida observou-se uma curva de histerese. Também foi verificado que para sistemas pequenos, a ponte líquida no modelo computacional se forma antes da previsão analítica. Para a análise termodinâmica, o modelo foi simplificado removendo as placas planas. Foi estudado o caso mais simples desse modelo que continha apenas duas partículas de líquido. Neste caso, calculou-se o calor específico e a energia interna numericamente, e esses resultados foram comparados com cálculos analíticos, validando o modelo numérico. Posteriormente, realizou-se um estudo da transição de fase desse sistema. Em seguida, a energia livre e a força da ponte líquida sobre as placas foram estudadas para diferentes temperaturas utilizando duas metodologias. Na primeira metodologia a entropia foi desprezada, na segunda metodologia, foi utilizando o método ``Overlapping Distribution\'\' que considera a entropia do sistema. Foi concluído que a entropia tem um efeito muito pequeno nas condições estudadas. O modelo é viável para a modelagem de fluidos a nível macroscópico e que portanto pode ser utilizado para quantificar não só as forças internas de estruturas pulmonares como também avaliar as energias liberadas após o processo de ruptura ou formação dessas pontes. / This work studied a three dimension lattice gas model to simulate macroscopic liquid systems. We used the model to study the energy and the forces involved during the process of liquid bridge formation and rupture between two parallel planes. The motivarion of this study was a physiological processes which occur inside the mammals lungs. Furthermore, a study was made to elucidate thermodynamic properties of the model. Concerning to physiological application, it was observed that the free energy of liquid bridge is smaller than the free energy of the droplet, for different liquid systems. With this observation, was proposed that this energy is dissipated as an acoustic energy. This sound should also exist in the rupture of liquid bridge. Comparing the free energy of liquid bridge in the formation and rupture process was observed a hysteresis curve. It was also found an effect of finite size in the formation of small size of the liquid bridge. In the numerical model, the liquid bridge is always formed earlier than expected from the analytical model. In the thermodynamic study, the model was simplified removing both parallel planes. First, the simplest case of this model was studied, only two liquid particles in a large gas lattice. In this case, the specific heat and internal energy was numerically studied and the results was compared with analytical calculation. Subsequently, we carried out a study of the phase transition of this system. Then, the free energy and the force generated between two parallel planes due the presence of the liquid bridge. This studied was performed using two different temperatures and two distinct methods. In the first method the entropy was neglected, and in the second method not. The second method was the ``Overlapping Distribution\'\'. It was concluded that the entropy has a very small effect in the studied conditions. The model is viable for modeling fluids at macroscopic level and therefore can be used to quantify not only the internal forces of the lung structures, but evaluate the energies released after the rupture process of the formation of these bridges.

Nesta dissertação, estudou-se um modelo tipo gás de rede em três dimensões para simular sistemas líquidos macroscópicos. Aplicou-se o modelo para o estudo das energias e forças envolvidas durante o processo de formação e ruptura de pontes líquidas entre duas placas planas. Esse estudo foi motivado por processos fisiológicos que acontecem no interior dos pulmões dos mamíferos. Além disso, foi feito um estudo das propriedades termodinâmicas do modelo. Com relação a aplicação fisiológica, observou-se que, no processo da formação da ponte líquida, a energia livre da ponte líquida é menor que a energia livre da gota, para diferentes sistemas líquidos. Com este resultado, fez a hipótese de que parte dessa energia é dissipada na forma de energia acústica. A emissão do som também deve ocorrer na ruptura da ponte líquida. Comparando a energia livre no processo de formação e ruptura da ponte líquida observou-se uma curva de histerese. Também foi verificado que para sistemas pequenos, a ponte líquida no modelo computacional se forma antes da previsão analítica. Para a análise termodinâmica, o modelo foi simplificado removendo as placas planas. Foi estudado o caso mais simples desse modelo que continha apenas duas partículas de líquido. Neste caso, calculou-se o calor específico e a energia interna numericamente, e esses resultados foram comparados com cálculos analíticos, validando o modelo numérico. Posteriormente, realizou-se um estudo da transição de fase desse sistema. Em seguida, a energia livre e a força da ponte líquida sobre as placas foram estudadas para diferentes temperaturas utilizando duas metodologias. Na primeira metodologia a entropia foi desprezada, na segunda metodologia, foi utilizando o método ``Overlapping Distribution\'\' que considera a entropia do sistema. Foi concluído que a entropia tem um efeito muito pequeno nas condições estudadas. O modelo é viável para a modelagem de fluidos a nível macroscópico e que portanto pode ser utilizado para quantificar não só as forças internas de estruturas pulmonares como também avaliar as energias liberadas após o processo de ruptura ou formação dessas pontes. / This work studied a three dimension lattice gas model to simulate macroscopic liquid systems. We used the model to study the energy and the forces involved during the process of liquid bridge formation and rupture between two parallel planes. The motivarion of this study was a physiological processes which occur inside the mammals lungs. Furthermore, a study was made to elucidate thermodynamic properties of the model. Concerning to physiological application, it was observed that the free energy of liquid bridge is smaller than the free energy of the droplet, for different liquid systems. With this observation, was proposed that this energy is dissipated as an acoustic energy. This sound should also exist in the rupture of liquid bridge. Comparing the free energy of liquid bridge in the formation and rupture process was observed a hysteresis curve. It was also found an effect of finite size in the formation of small size of the liquid bridge. In the numerical model, the liquid bridge is always formed earlier than expected from the analytical model. In the thermodynamic study, the model was simplified removing both parallel planes. First, the simplest case of this model was studied, only two liquid particles in a large gas lattice. In this case, the specific heat and internal energy was numerically studied and the results was compared with analytical calculation. Subsequently, we carried out a study of the phase transition of this system. Then, the free energy and the force generated between two parallel planes due the presence of the liquid bridge. This studied was performed using two different temperatures and two distinct methods. In the first method the entropy was neglected, and in the second method not. The second method was the ``Overlapping Distribution\'\'. It was concluded that the entropy has a very small effect in the studied conditions. The model is viable for modeling fluids at macroscopic level and therefore can be used to quantify not only the internal forces of the lung structures, but evaluate the energies released after the rupture process of the formation of these bridges.

Kawasaki disease (KD) is characterized by a systemic vasculitis of unknown etiology. More research indicates that KD is related to genetic. In 2003, Sekiya et al. studied the correlation of Th2-related genes and the KD in Japan. They found out that -431T allele would increase the concentration of Thymus and activation-regulated chemokine (TARC)/ CCL17 protein in serum by single nucleotide polymorphism (SNP) -431 C>T of chemokine TARC/ CCL17 operon 5¡¦-flanking region , which suggests that SNP has functionality. Therefore, this study explored the polymorphism and relationship between the regulation of chemokine of TARC/ CCL17 and KD. Firstly, we performed polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) to detect TARC/CCL17 -431 C>T genotype. Then enzyme immunoassay was used to detect TARC/CCL17 chemokine¡¦s expression. The results showed that the performance of TARC -431 C/T SNP, the alleles from KD patients with -431 T, were significantly less than the non-KD control group. It was observed that the -431 T alleles had a lower chance to occur in KD with aneurysms, but independent with coronary artery lesions (CAL). In addition, the acute stage of KD has a higher TARC protein expression, which gradually decreases during IVIG treatment period. However, the up-regulation of TARC protein may not be the direct consequence caused by the single nucleotide polymorphism of TARC -431 C>T.

Background: Kawasaki disease (KD) affects mainly children younger than five years of age, leading to coronary artery lesions, and even to life-threatening myocardial infarctions. Since 1976, Kawasaki disease has occurred among thousands of children in Taiwan. Evidence suggests that inflammation plays a key role in the pathogenesis of atherosclerosis. Significant determinants of high sensitivity C-reactive protein (hs-CRP), which is a sensitive indicator of inflammation, as well as white blood cell (WBC) count, and high-density lipoprotein cholesterol (HDLc) and coronary artery lesion were identified. The relationships between these factors¡¦ concentration and arterial lesion were likewise investigated and had reported. The aim of this study was to determine the serum levels of the hs-CRP, WBC count, and plasma HDLc levels in patients with later phase of KD. Methods and Materials: From July 2005 to June 2006, 97 children with Kawasaki disease at least 1 year after diagnosis were recruited in this study. These participated children had been diagnosed as KD and collected at the interval of 2001 to 2004. Diagnosis was based on the 1984 revised by the KD Research Committee in Japan. The participants were grouped into 45 patients with KD and coronary aneurysms (Group I), 52 patients with KD and normal coronary arteries (Group II), and 50 healthy age-matched children (Control Group III). Their WBC count, systemic and diastolic blood pressures, body mass index, age, sex, fasting total cholesterol concentrations, triglyceride, high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol, serum hs-CRP levels, and coronary artery lesion by cardioechography were recorded and compared. The analytical differences between hs-CRP, WBC count, and plasma HDLc levels and the coronary artery events in KD were examined. Results: Serum hs-CRP levels of Group I patients (mean 0.264 mg/dl) was significantly greater than that of Group II (mean 0.155 mg/dl, p=0.006) and Group III patients (mean 0.116 mg/dl, p =0.017). Similarly, the WBC count of Group I patients (mean 6,543.11/mm3) was significantly greater than that of Group II (mean 5,720.19/mm3, p=0.029), and Group III patients (mean 5,611.27/mm3, p =0.012). However, plasma HDLc levels of Group I patients (mean 41.42 mg/dl) was significantly lesser than that of Group II (mean 44.79 mg/dl, p=0.035), and Control Group III patients (mean 46.58 mg/dl, p=0.027). There was a positive association between hs-CRP and WBC count levels (r = 0.641, p < 0.05), but none between hs-CRP and plasma HDLc levels. Conclusions: There is the possibility of ongoing low-grade inflammation late after the convalescent phase of Kawasaki disease in children with coronary aneurysms, which may have a role in increasing coronary artery dysfunction. These results also suggest that hs-CRP, WBC count, and plasma HDLc levels are useful parameters for predicting formation of coronary artery lesion even in children after onset of KD.

INTRODUCTION: With the emergence of the COVID 19 pandemic, a new disease, Multisystem Inflammatory Syndrome in Children (MIS-C), had evolved. Increasing number of children are being reported to have MIS-C in the U.S. & worldwide. In the U.S. there are currently 2617 MISC cases reported. MIS-C & Kawasaki Disease (KD), have almost the same presentation, making clinical differentiation difficult. This study aims at differentiating KD & MIS-C which could assist clinicians to determine which one they could be dealing with in their practices. METHODS: Clinical features & laboratory values were collected from published studies found by queries on PubMed & other websites. Reported values were selected from published systemic reviews, meta-analyses, & large retrospective chart studies. RESULTS: In KD, the most prevalent clinical features are fever (100%) & the 5 KD-defining clinical features: oral mucosal changes (96.5%), rash (96%), non-purulent conjunctivitis (89%), extremity changes (75.6%), and cervical lymphadenopathy (62.7%). MIS-C also presents with fever (100%) but has lower prevalence of oral mucosal changes (23%), rash (38.2%), non-purulent conjunctivitis (44.0%), extremity changes (2.5%), & cervical lymphadenopathy (4%). MIS-C leads to higher rates of ventricular dysfunction (39.3%), myocarditis (23%), & shock. For cardiac biomarkers, MIS-C has elevated troponin I (x6 normal) & Beta Natriuretic Peptide (BNP) (x414 normal), while KD has elevations of troponin I (x1.9 normal) & BNP (x15 normal). MIS-C has higher elevations in ESR, CRP, and D-Dimer at x6, x30, and x40 from the normal values, respectively, while KD has elevations of x2.8, x2.1, x7.3 from the normal values, respectively. MIS-C is associated with neutrophilia, thrombocytopenia, & anemia in 22% of cases. KD is associated with mild neutrophilia & anemia. KD has thrombocytosis in the subacute phase (x1.46 normal). CONCLUSION: Our results demonstrated that there are overlaps & differences in clinical and laboratory features. Fever is present in both KD & MIS-C, however the 5 KD defining clinical features of KD are less frequent in MIS-C. MIS-C induces higher levels of troponin I & BNP, findings that could potentially explain for higher rates of ventricular dysfunction & myocarditis. MIS-C causes higher elevations in inflammatory markers & D-Dimers compared to KD. Uniquely, thrombocytopenia is commonly present in MISC rather than in KD. Differentiating KD & MIS-C can be challenging, but by focusing closely on the clinical & laboratory features, clinicians may be able to distinguish between the two &, therefore, deliver the most appropriate care to patients in their practices.

京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第21456号 / 社医博第90号 / 新制||社医||10(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 滝田 順子, 教授 小杉 眞司, 教授 三森 経世 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM