Fatal Kawasaki disease with coronary arteritis and no coronary aneurysms

Autoptic Findings in Cases of Sudden Death Due to Kawasaki Disease

Kawasaki disease (KD) is the second-most-common childhood vasculitis, and its etiology is still unknown today. Even though the acute illness is usually self-limiting, sometimes, it can generate complications, such as coronary artery aneurysms (CAA), acute myocardial infarction (AMI), heart failure, or arrhythmias, and can rarely cause sudden or unexpected deaths. We present a review of the literature, which collects autoptic and histopathological data relating to many of the cases of these deaths. On the basis of the titles and abstracts, we selected 54 scientific publications for a total of 117 cases. Among them, as expected, the majority of the deaths were due to AMI (41.03%), arrhythmia (8.55%), acute coronary syndrome (8.55%), and CAA rupture (11.97%), involving mostly 20-year-olds or younger individuls (69.23%). This is not surprising since the CAs are the most involved arteries. Gross autoptic and histopathological findings are reported in the paper. Our work revealed that, when compared with the incidence of KD, only a few cases suffered from sudden death, underwent an autoptic examination, and were then described in the literature. We suggest that researchers should perform autopsies to gain a better understanding of the molecular pathways involved in KD so as to propose further innovative therapeutic protocols or implement more appropriate prevention schemes.

Mechanistic Target of Rapamycin Inhibition Prevents Coronary Artery Remodeling in a Murine Model of Kawasaki Disease

OBJECTIVE

Remodeling of the coronary arteries is a common feature in severe cases of Kawasaki disease (KD). This pathology is driven by the dysregulated proliferation of vascular fibroblasts, which can lead to coronary artery aneurysms, stenosis, and myocardial ischemia. We undertook this study to investigate whether inhibiting fibroblast proliferation might be an effective therapeutic strategy to prevent coronary artery remodeling in KD.

METHOD

We used a murine model of KD (induced by the injection of the Candida albicans water-soluble complex [CAWS]) and analyzed patient samples to evaluate potential antifibrotic therapies for KD.

RESULTS

We identified the mechanistic target of rapamycin (mTOR) pathway as a potential therapeutic target in KD. The mTOR inhibitor rapamycin potently inhibited cardiac fibroblast proliferation in vitro, and vascular fibroblasts up-regulated mTOR kinase signaling in vivo in the CAWS mouse model of KD. We evaluated the in vivo efficacy of mTOR inhibition and found that the therapeutic administration of rapamycin reduced vascular fibrosis and intimal hyperplasia of the coronary arteries in CAWS-injected mice. Furthermore, the analysis of cardiac tissue from KD fatalities revealed that vascular fibroblasts localizing with inflamed coronary arteries up-regulate mTOR signaling, confirming that the mTOR pathway is active in human KD.

CONCLUSION

Our findings demonstrate that mTOR signaling contributes to coronary artery remodeling in KD, and that targeting this pathway offers a potential therapeutic strategy to prevent or restrict this pathology in high-risk KD patients.

Allograft Inflammatory Factor-1 Links T-Cell Activation, Interferon Response, and Macrophage Activation in Chronic Kawasaki Disease Arteritis

BACKGROUND

Kawasaki disease (KD) is widely viewed as an acute arteritis. However, our pathologic studies show that chronic coronary arteritis can persist long after disease onset and is closely linked with arterial stenosis. Transcriptome profiling of acute KD arteritis tissues revealed upregulation of T lymphocyte, type I interferon, and allograft inflammatory factor-1 (AIF1) genes. We determined whether these immune responses persist in chronic KD arteritis, and we investigated the role of AIF1 in these responses.

METHODS

Gene expression in chronic KD and childhood control arteries was determined by real-time reverse-transcriptase polymerase chain reaction, and arterial protein expression was determined by immunohistochemistry and immunofluorescence. Allograft inflammatory factor-1 small-interfering ribonucleic acid macrophage treatment was performed to investigate the role of AIF1 in macrophage and T lymphocyte activation.

RESULTS

Allograft inflammatory factor-1 protein was highly expressed in stenotic KD arteries and colocalized with the macrophage marker CD68. T lymphocyte and interferon pathway genes were significantly upregulated in chronic KD coronary artery tissues. Alpha interferon-induced macrophage expression of CD80 and major histocompatibility complex class II was dependent on AIF1, and macrophage expression of AIF1 was required for antigen-specific T lymphocyte activation.

CONCLUSIONS

Allograft inflammatory factor-1, originally identified in posttransplant arterial stenosis, is markedly upregulated in KD stenotic arterial tissues. T lymphocyte and type I interferon responses persist in chronic KD arteritis. Allograft inflammatory factor-1 may play multiple roles linking type I interferon response, macrophage activation, and antigen-specific T lymphocyte activation. These results suggest the likely importance of lymphocyte-myeloid cell cross-talk in the pathogenesis of KD arteritis and can inform selection of new immunotherapies for clinical trials in high-risk KD children.

Kawasaki disease: insights into pathogenesis and approaches to treatment

This Review summarizes recent advances in understanding of the pathologic processes and pathophysiologic mechanisms leading to coronary arteritis in Kawasaki disease, and describes current approaches to its treatment. Kawasaki disease is the most common cause of acquired heart disease among children in developed countries, in whom the resulting coronary artery abnormalities can cause myocardial ischaemia, infarction and even death. Epidemiologic data strongly suggest an infectious aetiology, although the causative agent has yet to be identified. Genetic factors also increase susceptibility to Kawasaki disease, as indicated by its strikingly high incidence rate in children of Asian ethnicity and by an increased incidence in first-degree family members. The treatment of Kawasaki disease is based on timely administration of intravenous immunoglobulin and aspirin. However, the management of patients who do not respond to this standard therapy remains challenging; although several options are available, comparative data on which to base treatment decisions are scarce. The added value of adjunctive therapy with corticosteroids in patients at particularly high risk of coronary complications has been demonstrated in Japanese populations, but identification of high-risk patients has proven to be difficult in ethnically diverse populations.

Vascular health late after Kawasaki disease: implications for accelerated atherosclerosis

Kawasaki disease (KD), an acute vasculitis that primarily affects young children, is the most common acquired paediatric cardiovascular disease in developed countries. While sequelae of arterial inflammation in the acute phase of KD are well documented, its late effects on vascular health are increasingly unveiled. Late vascular dysfunction is characterized by structural alterations and functional impairment in term of arterial stiffening and endothelial dysfunction and shown to involve both coronary and systemic arteries. Further evidence suggests that continuous low grade inflammation and ongoing active remodeling of coronary arterial lesions occur late after acute illness and may play a role in structural and functional alterations of the arteries. Potential importance of genetic modulation on vascular health late after KD is implicated by associations between mannose binding lectin and inflammatory gene polymorphisms with severity of peripheral arterial stiffening and carotid intima-media thickening. The changes in cholesterol and lipoproteins levels late after KD further appear similar to those proposed to be atherogenic. While data on adverse vascular health are less controversial in patients with persistent or regressed coronary arterial aneurysms, data appear conflicting in individuals with no coronary arterial involvements or only transient coronary ectasia. Notwithstanding, concerns have been raised with regard to predisposition of KD in childhood to accelerated atherosclerosis in adulthood. Until further evidence-based data are available, however, it remains important to assess and monitor cardiovascular risk factors and to promote cardiovascular health in children with a history of KD in the long term.

Three linked vasculopathic processes characterize Kawasaki disease: a light and transmission electron microscopic study

BACKGROUND

Kawasaki disease is recognized as the most common cause of acquired heart disease in children in the developed world. Clinical, epidemiologic, and pathologic evidence supports an infectious agent, likely entering through the lung. Pathologic studies proposing an acute coronary arteritis followed by healing fail to account for the complex vasculopathy and clinical course.

METHODOLOGY/PRINCIPAL FINDINGS

Specimens from 32 autopsies, 8 cardiac transplants, and an excised coronary aneurysm were studied by light (n=41) and transmission electron microscopy (n=7). Three characteristic vasculopathic processes were identified in coronary (CA) and non-coronary arteries: acute self-limited necrotizing arteritis (NA), subacute/chronic (SA/C) vasculitis, and luminal myofibroblastic proliferation (LMP). NA is a synchronous neutrophilic process of the endothelium, beginning and ending within the first two weeks of fever onset, and progressively destroying the wall into the adventitia causing saccular aneurysms, which can thrombose or rupture. SA/C vasculitis is an asynchronous process that can commence within the first two weeks onward, starting in the adventitia/perivascular tissue and variably inflaming/damaging the wall during progression to the lumen. Besides fusiform and saccular aneurysms that can thrombose, SA/C vasculitis likely causes the transition of medial and adventitial smooth muscle cells (SMC) into classic myofibroblasts, which combined with their matrix products and inflammation create progressive stenosing luminal lesions (SA/C-LMP). Remote LMP apparently results from circulating factors. Veins, pulmonary arteries, and aorta can develop subclinical SA/C vasculitis and SA/C-LMP, but not NA. The earliest death (day 10) had both CA SA/C vasculitis and SA/C-LMP, and an "eosinophilic-type" myocarditis.

CONCLUSIONS/SIGNIFICANCE

NA is the only self-limiting process of the three, is responsible for the earliest morbidity/mortality, and is consistent with acute viral infection. SA/C vasculitis can begin as early as NA, but can occur/persist for months to years; LMP causes progressive arterial stenosis and thrombosis and is composed of unique SMC-derived pathologic myofibroblasts.

Cardiac ischemia in pediatric patients

Cardiac ischemia in children is usually not an isolated disease in an otherwise normally formed coronary artery but is part of more complex congenital or acquired diseases. Although cardiac ischemia is not a frequent occurrence, it must be recognized as a serious, life-threatening event. This article lists and characterizes major causes of cardiac ischemia in children, describes signs and symptoms of each, and provides therapeutic considerations.

Kawasaki disease with severe cardiac sequelae: lessons from recent New Zealand experience

OBJECTIVES

To review recent cases of Kawasaki disease (KD) with significant cardiac sequelae in New Zealand. It is known that intravenous immunoglobulin (IVIG) reduces the risk of coronary artery aneurysm formation if given within 8-10 days of onset of KD.

METHODS

Retrospective review of medical course, criteria for KD, laboratory and cardiac findings for six children identified with KD and significant coronary artery sequelae.

RESULTS

There was delay in diagnosis of KD in three of the six children. Three cases were atypical by extremes of age (2 months, 10 years, 14 years). By definition all six children had significant coronary artery involvement. One patient had a thrombus detected in a coronary aneurysm 3 weeks after KD. One patient underwent coronary artery bypass grafting for unstable angina 2 years after KD. One patient developed coronary artery aneurysms after an initial 'toxic shock' type illness evolving to KD. Three patients died, one due to rupture of a coronary artery aneurysm, two from rapid early coronary artery obstruction occurring at three and 4 months after initial KD.

CONCLUSIONS

Kawasaki disease remains an important cause of mortality and morbidity for children. Diagnostic delay beyond 8 days reduces the chances of successful IVIG therapy in KD. Current studies supported by the Paediatric Surveillance Unit should establish the epidemiology of KD in New Zealand.

Longstanding obliterative panarteritis in Kawasaki disease: lack of cyclosporin A effect

Kawasaki disease is a childhood vasculitis of medium-sized vessels, affecting the coronary arteries in particular. We have treated a therapy-resistant child who met all diagnostic criteria for Kawasaki disease. After the boy was given intravenous immunoglobulins and salicylates, as well as several courses of pulsed methylprednisolone, disease recurred and coronary artery lesions became progressively detectable. Cyclosporin A was started and seemed clinically effective. In contrast to the positive effect on inflammatory parameters, ie, C-reactive protein and white blood cell counts, a novel plasma marker for cytotoxicity (granzyme B) remained elevated. Coronary disease progressed to fatal obstruction and myocardial infarction. Echocardiography, electrocardiograms, and myocardial creatine phosphokinase did not predict impending death. At autopsy an obliterative panarteritis was observed resulting from massive fibrointimal proliferation, affecting the aorta and several large and medium-sized arteries. Immunophenotypic analysis of the inflammatory infiltrates in arteries revealed mainly granzyme-positive cytotoxic T cells and macrophages in the intima and media, as well as nodular aggregates of T cells, B cells, and plasma cells in the adventitia of affected arteries. These findings further endorse the role of specific cellular and humoral immunity in Kawasaki disease. Unremitting coronary arteritis and excessive smooth muscle hyperplasia resulted in coronary occlusion despite the use of cyclosporin A.