Coronavirus disease 2019 (COVID-19): A systematic review of 133 Children that presented with Kawasaki-like multisystem inflammatory syndrome.

Kawasaki-like disease (KLD) and multisystem inflammatory syndrome in children (MIS-C) are considered as challenges for pediatric patients under the age of 18 infected with coronavirus disease 2019 (COVID-19). A systematic search was performed on July 2, 2020, and updated on December 1, 2020, to identify studies on KLD/MIS-C associated with COVID-19. The databases of Scopus, PubMed, Web of Science, Embase, and Scholar were searched. The hospitalized children with a presentation of Kawasaki disease (KD), KLD, MIS-C, or inflammatory shock syndromes were included. A total number of 133 children in 45 studies were reviewed. A total of 74 (55.6%) cases had been admitted to pediatric intensive care units (PICUs). Also, 49 (36.8%) patients had required respiratory support, of whom 31 (23.3%) cases had required mechanical ventilation/intubation, 18 (13.5%) cases had required other oxygen therapies. In total, 79 (59.4%) cases had been discharged from hospitals, 3 (2.2%) had been readmitted, 9 (6.7%) had been hospitalized at the time of the study, and 9 (6.7%) patients had expired due to the severe heart failure, shock, brain infarction. Similar outcomes had not been reported in other patients. Approximately two-thirds of the children with KLD associated with COVID-19 had been admitted to PICUs, around one-fourth of them had required mechanical ventilation/intubation, and even some of them had been required readmissions. Therefore, physicians are strongly recommended to monitor children that present with the characteristics of KD during the pandemic as they can be the dominant manifestations in children with COVID-19.

Kawasaki disease shock syndrome: Unique and severe subtype of Kawasaki disease.

BACKGROUND: Kawasaki disease shock syndrome (KDSS) is an uncommon presentation of Kawasaki disease (KD). KDSS has been associated with more severe markers of inflammation, coronary abnormalities and i.v. immunoglobulin (IVIG) resistance. METHODS: A retrospective, descriptive study of children with KDSS in two hospitals was performed. Relevant articles about KD and shock were collected, and demographic data, clinical presentation, laboratory variables, echocardiogram findings, treatment and special features were analyzed when available. Twelve patients diagnosed with KDSS were retrospectively reviewed from two centers in Mexico, along with 91 additional cases from the literature. RESULTS: Seventy-two patients presented with complete KD (69.9%), and 30.1% (31/103) had unusual KD manifestations. The most frequent diagnosis at the time of admission was toxic shock syndrome (TSS; n = 20). Sixteen of the 20 had coronary artery abnormalities. Overall, abnormalities in the coronary arteries were documented in 65% of the patients. The mortality rate was 6.8%. CONCLUSION: The presence of coronary aneurysms was significantly and positively correlated with male gender, IVIG resistance, inotrope treatment, cardiac failure, abdominal pain and neurological symptoms. IVIG-resistant patients had higher neutrophil : lymphocyte ratio. Abdominal symptoms, hypoalbuminemia and elevated C-reactive protein were present in almost all of the patients. Multisystem involvement with atypical presentation in KDSS is frequent. An important differential diagnosis is TSS. Mechanical ventilation, gastrointestinal and neurological symptoms were associated with IVIG resistance and the presence of coronary aneurysms. The first line of treatment includes IVIG and pulse corticosteroids; in severe cases, infliximab, anakinra, cyclosporine or plasmapheresis are alternative treatment options.

Arterial immune protein expression demonstrates the complexity of immune responses in Kawasaki disease arteritis.

A more complete understanding of immune-mediated damage to the coronary arteries in children with Kawasaki disease (KD) is required for improvements in patient treatment and outcomes. We recently reported the transcriptional profile of KD coronary arteritis, and in this study sought to determine protein expression of transcriptionally up-regulated immune genes in KD coronary arteries from the first 2 months after disease onset. We examined the coronary arteries of 12 fatal KD cases and 13 childhood controls for expression of a set of proteins whose genes were highly up-regulated in the KD coronary artery transcriptome: allograft inflammatory factor 1 (AIF1), interleukin 18 (IL-18), CD74, CD1c, CD20 (MS4A1), Toll-like receptor 7 (TLR-7) and Z-DNA binding protein 1 (ZBP1). Immunohistochemistry and immunofluorescence studies were performed to evaluate protein expression and co-localization, respectively. AIF1 was expressed transmurally in KD arteritis and localized to macrophages and myeloid dendritic cells. CD74, which interacts with major histocompatibility complex (MHC) class II on antigen-presenting cells, localized to the intima-media. CD1c, a marker of myeloid dendritic cells, was expressed in a transmural pattern, as were IL-18 and CD20. ZBP1 and TLR-7 were up-regulated compared to controls, but less highly compared to the other proteins. These findings provide evidence of antigen presentation and interferon response in KD arteritis. In combination with prior studies demonstrating T lymphocyte activation, these results demonstrate the complexity of the KD arterial immune response.

Cardiac Events and the Maximum Diameter of Coronary Artery Aneurysms in Kawasaki Disease.

OBJECTIVES: To clarify the occurrence of cardiac events based on the maximal diameter of the maximal coronary artery aneurysm (CAA) in Kawasaki disease (KD). STUDY DESIGN: Two hundred fourteen patients (160 male and 54 female) who had had at least 1 CAA in the selective coronary angiogram less than 100 days after the onset of KD were studied. We measured the maximal CAA diameters in the major branches of the initial coronary angiograms. Death, myocardial infarction and coronary artery revascularization were included as cardiac events in this study. We divided the patients into three groups based on the maximal CAA diameter (large ≥8.0 mm; medium ≥6.0 mm and <8.0 mm; small <6.0 mm). Further, we also analyzed the cardiac events based on laterality of maximal CAA (bilateral, unilateral) and body surface area (BSA). RESULTS: Cardiac events occurred in 44 patients (21%). For BSA < 0.50 m2, the 30-year cardiac event-free survival in the large and medium groups was 66% (n = 38, 95% CI, 49-80) and 62% (n = 27, 95% CI, 38-81), respectively. For BSA ≥ 0.50 m2, that in large group was 54% (n = 58, 95% CI, 40-67). There were no cardiac events in the medium group for BSA ≥0.50 m2 (n = 36) and the small group (n = 56). In the large analyzed group, the 30-year cardiac event-free survival in the bilateral and unilateral groups was 40% (n = 48, 95% CI, 27-55) and 78% (n = 48, 95% CI, 63-89), respectively (P < .0001). CONCLUSIONS: The group with the highest risk of cardiac events was the patient group with the maximal CAA diameter ≥6.0 mm with BSA < 0.50 m2 and the maximal CAA diameter ≥8.0 mm with BSA ≥ 0.50 m2. At 30 years after the onset of KD, cardiac event-free survival was about 60%. Given the high rate of cardiac events in this patient population, life-long cardiovascular surveillance is advised.

Mortality in children with Kawasaki disease: 20 years of experience from a tertiary care centre in North India.

Kawasaki disease (KD) is a common vasculitic disorder of childhood. Reported mortality in KD in Japan is 0.014%. We report the clinical and laboratory profile of 4 children who succumbed to KD during the period January 1994 to March 2015 at the Paediatric Allergy Immunology Unit, Advanced Paediatrics Centre, Post Graduate Institute of Medical Education and Research Centre, Chandigarh, India. A total of 460 children were diagnosed with KD based on the American Heart Association criteria. Male to female ratio was 1.96:1 and 106 children were aged 2 years or less. Children with KD received 2 g/kg of intravenous immunoglobulin (IVIg). In addition, aspirin was administered in doses of 30-50 mg/kg/day during the acute phase and 3-5 mg/kg/day thereafter. 2-D echocardiography was carried out once during the acute phase and approximately 6-8 weeks later on follow-up. Four children (2 boys, 2 girls) died during this period and their details were analysed from their clinical records. All 4 were under 2 years of age and had had significant delays in diagnosis and referral. Symptomatic myocarditis was noted in 2 children, while 2 of them had thrombocytopenia. We report a mortality of 0.87% in children with KD. Delays in diagnosis and referral contributed significantly to this mortality. To the best of our knowledge, this is the first report on mortality in KD from any developing nation.

Cardiac Complications in 38 Cases of Kawasaki Disease with Coronary Artery Aneurysm Diagnosed by Echocardiography.

BACKGROUND: The long-term prognosis of patients with Kawasaki disease (KD) complicated by coronary artery aneurysm (CAA) is unclear. The aim of this study was to evaluate the complications of KD with CAAs. METHOD: We retrospectively analyzed the clinical data and complications of 38 KD patients with CAAs who were treated and underwent regular follow-up with echocardiography between January 1989 and May 2013. RESULTS: During a period of 29 days to 19 years after disease onset, complications seen included coronary stenosis and occlusion (six patients), thrombosis (17 patients), myocardial infarction (six patients), and calcification of CAAs (seven patients). Rupture of giant CAAs occurred in two patients and caused sudden death in one of these patients at 29 days and in the other patient at 5 months after disease onset. A total of seven deaths occurred, with five deaths caused by myocardial infarction. Three of these had undiagnosed incomplete KD or had not received regular treatment, while two experienced sudden death after several asymptomatic myocardial infarctions. CONCLUSION: Cardiac complications of KD with CAAs include thrombosis, coronary stenosis, myocardial infarction, sudden death, and calcification. Although rare, rupture of giant CAAs is fatal and might occur earlier after the onset of disease. Mortality occurred primarily in the earlier cases when anticoagulant therapy was insufficient and in patients who did not receive regular treatment. Echocardiography can provide reliable information for assessing the progression and prognosis of this condition.

Mortality among Japanese with a history of Kawasaki disease: results at the end of 2009.

BACKGROUND: The long-term outcomes of Kawasaki disease (KD) are unknown. METHODS: Fifty-two collaborating hospitals collected data on all patients who had received a new definite diagnosis of KD between July 1982 and December 1992. Patients were followed until December 31, 2009 or death. Standardized mortality ratios (SMRs) were calculated based on Japanese vital statistics data. RESULTS: Of the 6576 patients enrolled, 46 (35 males and 11 females) died (SMR: 1.00; 95% CI: 0.73-1.34). Among persons without cardiac sequelae, SMRs were not high after the acute phase of KD (SMR: 0.65; 95% CI: 0.41-0.96). Among persons with cardiac sequelae, 13 males and 1 female died during the observation period (SMR: 1.86; 95% CI: 1.02-3.13). CONCLUSIONS: In this cohort, the mortality rate among Japanese with cardiac sequelae due to KD was significantly higher than that of the general population. In contrast, the rates for males and females without sequelae were not elevated.

The fate and observed management of giant coronary artery aneurysms secondary to Kawasaki disease in the Province of Quebec: the complete series since 1976.

Most population-based series reporting on the coronary artery complications after Kawasaki disease (KD) originate from Japan. This study aimed to describe the complete series of KD patients from the province of Quebec in Canada, a predominantly Caucasian population. This retrospective case series was conducted by the Quebec Kawasaki Disease Registry, a multi-institutional collaboration reviewing 89.8 % of all KD cases identified by the Ministry of Health records of hospitalization for KD from the first recognized case in 1976 until 2008. This report describes the course of 38 patients (95 % Caucasians) with a diagnosis of giant coronary artery aneurysms, which represent 1.9 % of all reviewed cases and 26.2 % of those with a coronary aneurysm 5 mm or larger. The age at diagnosis was 5.52 ± 4.04 years, and the follow-up period was 9.26 ± 6.9 years. The KD diagnosis was retrospective at autopsy in two cases and via echocardiography in four cases. The overall freedom from coronary thrombi, coronary intervention, or death was respectively 63.9, 67.5, and 85.1 %. Five deaths occurred as follows: 21 days after onset of fever (2 cases), 1.8 months after onset of fever (1 case), 1 year after retrospectively presumed but previously undiagnosed KD (1 case), and 5.7 years after a KD diagnosis (1 case of sudden cardiac death). Percutaneous transluminal coronary revascularization was attempted in four cases (1 requiring cardiac transplantation), and two other cases underwent primary bypass graft surgery. Whereas this study investigated cases of KD with severe coronary sequelae in the Province of Quebec, larger collaborative studies should be conducted for further understanding of the disease in predominantly non-Asian populations.

Long-term prognosis of patients with Kawasaki disease complicated by giant coronary aneurysms: a single-institution experience.

BACKGROUND: Some patients with Kawasaki disease develop giant coronary aneurysms and coronary stenosis, leading to ischemic heart disease. The aim of this study was to determine the long-term prognosis of patients with Kawasaki disease with giant aneurysms. METHODS AND RESULTS: From our institutional database, 76 patients (57 men and 19 women) who developed giant aneurysms after January 1, 1972, were identified. Information on patient demographics, catheter and surgical interventions, and most recent status was collected from medical charts and patients' contacts. From these data, we calculated the survival rate and cumulative coronary intervention rate. The average age at onset was 2.9±2.9 years, and the median observational period was 19 years. During this period, 7 patients died and 1 patient underwent a heart transplantation, resulting in 95%, 88%, and 88% survival rates at 10, 20, and 30 years after the onset of KD, respectively. On the other hand, catheter and surgical coronary interventions (median, 1 intervention; range, 1 to 7 interventions) were performed to alleviate coronary ischemia in 46 patients (61%) at 1 month to 21 years (mode at 1 month) after onset, resulting in 28%, 43%, and 59% cumulative coronary intervention rates at 5, 15, and 25 years after onset, respectively. CONCLUSIONS: The long-term survival of patients with Kawasaki disease complicated by giant coronary aneurysms is moderately good with multiple catheter and surgical interventions. Further research should focus on the prevention of coronary vascular remodeling and on the indications for and effectiveness of percutaneous and surgical coronary interventions.

The 30-year outcome for patients after myocardial infarction due to coronary artery lesions caused by Kawasaki disease.

This study determined the long-term outcome for patients after myocardial infarction (MI) due to Kawasaki disease (KD). Retrospective analysis was performed for 60 patients who had experienced MI between 1976 and 2007. Their ages at the initial MI ranged from 3 months to 33 years (median, 2 years). The maximum follow-up period after the initial MI was 33 years (median, 16 years). Coronary angiography, left ventriculography, and radioisotope myocardial perfusion imaging (MPI) had been performed for 56 patients more than 2 months after MI when all were in stable condition. The survival rate and ventricular tachycardia (VT)-free survival rate were calculated after the initial MI by the Kaplan-Meier method. Both sustained and nonsustained VT were included. Furthermore, the Cox proportional hazards model was used to analyze which factors influenced the post-MI outcome and which influenced the appearance of VT. The 30-year survival rate was 62.7% (95% confidence interval [CI], 44.6-77.9%), and the 25-year VT-free survival rate after MI was 28.5% (95% CI 15.4-46.5%). The postinfarction left ventricular ejection fraction (LVEF) was related to the outcome in this population (hazard ratio 0.86; 95% CI 0.75-0.95; P = 0.002), whereas the development of VT was related to the post-LVEF and to perfusion abnormalities in MPI (P = 0.0002). The 30-year survival rate after MI was poor for the patients with a low LVEF. With aging, the existence of nonviable myocardium in the infarct area can induce fatal ventricular arrhythmia more than 10 years after the original MI.

The pathology of Kawasaki disease aortitis: a study of 37 cases.

BACKGROUND: Kawasaki disease (KD) is a systemic vasculitis syndrome that occurs most frequently in children. Most clinical and pathological studies have focused on its coronary artery lesions. To date, no detailed studies of the aorta have been conducted. We studied KD autopsy cases with the aims of clarifying the time-course of changes in aortic lesions, the differences in the inflammatory cells and degree of inflammation at various aortic sites, and the progression of the inflammation. MATERIALS AND METHODS: The study materials were aortic specimens taken from 37 KD autopsy cases (acute phase: 19; remote phase: 18). Twenty-seven of the cases also had coronary aneurysms. We chose 3 aortic sites, i.e., the thoracic aorta, aortic root and aortic bifurcation, and we histologically observed and compared those sites in regard to the changes with time, the kinds of infiltrating cells and the number of inflammatory cells. We also observed the relationship between the vasa vasorum and inflammatory cell localization in the tunica media, and examined the progression of inflammation in the tunica media. RESULTS: Destruction of the vascular architecture was not seen in any of the 37 cases, but inflammatory cell infiltration was observed in 90% of the acute-phase cases. The inflammatory cell infiltration involved the tunica intima and tunica adventitia of the aorta on the 6th disease-day, and all layers of the aorta on the 13th disease-day; the infiltration peaked on the 18th disease-day. The infiltration gradually disappeared thereafter, and no significant infiltration was seen in the remote phase. The infiltrating inflammatory cells consisted mainly of CD163-positive macrophages. Comparison of the 3 sites of the aorta showed that the inflammatory cell infiltration was more severe in the aortic root and aortic bifurcation than in the thoracic aorta. The progression of inflammation to the aortic tunica media from the adventitia showed 2 patterns: 1 in which macrophages were aggregated around the vasa vasorum; and a second in which there was no such aggregation around the vasa vasorum, but there was diffuse inflammatory cell infiltration of the tunica media. In addition to this, there were findings of direct infiltration of cells from the tunica intima into the tunica media. CONCLUSION: Inflammation in KD occurs in the aorta. The changes with time and the kinds of infiltrating cells were the same as reported to date for coronary arteries in KD. There were differences in the degree of inflammation among the 3 aortic sites. It can be thought that the inflammation from the adventitia to the media progresses via the vas vasorum, and also, there is a possibility of spreading directly. From the intima to the media, inflammation spreads directly. However, formation of aneurysms and destruction of the vascular architecture of the aorta were absent in this study, unlike in coronary arteries.

Twenty-five-year outcome of pediatric coronary artery bypass surgery for Kawasaki disease.

BACKGROUND: The long-term outcome of pediatric coronary artery bypass for patients with severe inflammatory coronary sequelae secondary to Kawasaki disease is unknown. METHODS AND RESULTS: One hundred fourteen children and adolescents ranging in age from 1 to 19 (median, 10) years at operation were followed up for as long as 25 years with a median of 19 years. The number of distal anastomoses was 1.7+/-0.8 per patient, and the internal thoracic artery was used in all but 3, most frequently for left anterior descending artery lesions. Saphenous vein grafts were used in 24 patients, mostly for non-left anterior descending artery lesions. Patients underwent multiple angiograms to evaluate their coronary and graft status. There was no operative or hospital mortality. Both 20- and 25-year survival rates were 95% (95% confidence interval [CI], 88 to 98). Five deaths occurred, all cardiac in origin. Cardiac event-free rates at 20 and 25 years were 67% and 60% (95% CI, 46 to 72), respectively. Percutaneous coronary intervention and reoperation were the most common events. Overall, the 20-year graft patency rate was 87% (95% CI, 78 to 93) for internal thoracic artery grafts (n=154) and 44% (95% CI, 26 to 61) for saphenous vein grafts (n=30) (P<0.001), and the rate for non-left anterior descending artery lesions was also significantly better for arterial grafts (87% [95% CI, 73 to 94]; n=59) than for saphenous vein grafts (42% [95% CI, 23 to 60]; n=27) (P=0.002). Eighty-eight patients (77%) remain on medications, but all 109 survivors are presently symptom free in their daily activities. CONCLUSIONS: Although the 25-year survival was excellent after pediatric coronary bypass for Kawasaki disease, the event-free rate declined progressively. This reality mandated continued follow-up. Reinterventions successfully managed most cardiac events. An internal thoracic artery graft was the most favorable for children.

Multisystem Inflammatory Syndrome Associated With Coronavirus Disease in Children: A Multi-centered Study in Belém, Pará, Brazil.

We described the characteristics of 11 children with pediatric multisystem inflammatory syndrome-temporally associated with SARS-CoV-2. The main clinical indications for hospital admission were vasogenic toxic shock (n = 2), Kawasaki disease (n = 4), and Kawasaki disease shock syndrome (n = 5). The echocardiography findings were abnormal in 63% of cases. All patients had 2 or more organ dysfunctions, and the mortality rate was 18%.

Kawasaki Syndrome in Texas.

The authors examined hospitalization rates of Kawasaki Syndrome (KS) among Texas children to isolate clusters, identify demographic disparities, and suggest possible causative factors. Using a retrospective cross-sectional study design, they studied 330 KS cases from 2,818,460 hospital discharges. The majority of the cases (61.5%) occurred within the 1-4-years-old category, representing the highest hospitalization rate (14.3 per 100,000 children). Almost 75% of the KS population was less than 5 years old, with hospitalization rates approximately 8 times higher than that of all other children (p < .05). KS diagnosis occurred for only 49.4% of all KS cases upon admission. Along with high-density clusters identified in major metropolitan areas, the authors found the highest rates of KS among Asian and Pacific Islander and non-Hispanic black children. Genetic predispositions and access to healthcare issues may explain the results. The authors recommend improving educational initiatives with healthcare providers and establishing KS as a reportable condition.

[Pediatric coronary artery bypass grafting for Kawasaki disease: 20-years' outcome].

The 20-year clinical outcome is excellent for the children with Kawasaki disease who underwent a bypass operation using the internal thoracic artery. This operation is feasible from 1 year-old children and in our experience with more than 110 patients, the operative and hospital mortality was 0%, and the 20-year survival was 98.4%. The recent patency rate was nearly 95% for the internal thoracic artery graft regardless of the patient's age, and the 20-year patency was 87.1%. Moreover, the wall characteristics of the internal thoracic artery was quite smooth and apparently well adapting to the somatic growth of children over 20 years after the operation. In contrast, vein grafts had a lower patency of 57% at 20 years. In addition, patent vein grafts showed irregularity of the wall and in some, atherosclerotic changes were observed. Pediatric coronary bypass operation utilizing the internal thoracic artery is proved to be a golden standard treatment modality for complicated coronary artery obstructive disease due to Kawasaki disease, based upon the 20-year clinical and angiographic follow-ups.

Histopathological aspects of cardiovascular lesions in Kawasaki disease.

Kawasaki disease (KD) is the commonest vasculitic syndrome. It affects medium-sized arteries, principally the coronary arteries. Histologically, coronary arteritis begins at 6 to 8 days after the onset of KD and the inflammation rapidly involves all layers of the artery. This results in severe damage to the structural components of the artery leading to arterial dilation. The inflammatory infiltrate in KD arteritis is characterized predominantly by infiltration of monocytes and macrophages. Activated neutrophils, monocytes and macrophages are believed to be involved in the initial stage of coronary arteritis. Inflammatory cell infiltration may continue for up to 25 days of disease following which the inflammatory cells gradually decline in number. Inflammatory lesions in the arteries are relatively synchronous as they evolve from an acute to the chronic stage. If a giant aneurysm remains or vessel recanalization occurs after thrombotic occlusion of an aneurysm, the remodeling of vascular structures may continue for a much longer time.

Kawasaki Disease in India, Lessons Learnt Over the Last 20 Years.

Over the last 20 years, Kawasaki disease is being increasingly recognized in India and it may soon replace acute rheumatic fever to become the commonest cause of acquired heart disease amongst children. However, the vast majority of children with Kawasaki disease in India are still not being diagnosed. Diagnosis of Kawasaki disease is based on a constellation of clinical findings which have a typical temporal sequence. All pediatricians must we familiar with the nuances involved in arriving at a diagnosis of Kawasaki disease. With early diagnosis and prompt treatment, the risk of coronary artery abnormalities can be significantly reduced.

Kawasaki disease in infants below 6 months: a clinical conundrum?

AIM: Kawasaki disease (KD) is a medium vessel vasculitis of childhood. In infancy KD is often characterized by incomplete and atypical forms. There is paucity of literature on KD in children below 6 months and there are no data from any developing country. This study defines the profile of children with KD below 6 months at our centre. METHODS: During January 1994 to March 2015, 460 children were diagnosed with KD and 17 (3.6%) were below 6 months. Diagnosis was based on American Heart Association (AHA) criteria. All children were treated with intravenous immunoglobulin and aspirin; three also received infliximab. RESULTS: Mucosal changes were present in 11 patients (64%); extremity changes in 11 (64%); rash in nine (53%); conjunctival injection in eight (47%); and cervical lymphadenopathy in three (17%). Irritability was noted in 15 patients (88%); four (23%) had respiratory symptoms; and two (11%) had bacille Calmette-Guérin scar reactivation. Fifteen (88%) had incomplete KD. Twelve patients were diagnosed beyond day 10 of illness. Thrombocytopenia was seen in four. Coronary artery abnormalities were present in six (35%) patients. Two children died from disease-related complications - one of these had giant coronary artery aneurysms. CONCLUSION: Our data show that incomplete forms of KD are commonly seen in children below 6 months of age, thereby resulting in delayed diagnoses. Pediatricians need to have a high index of suspicion of KD when dealing with a young infant with unexplained fever beyond 5 days. The AHA criteria appear to be inadequate for diagnosing KD in infants below 6 months.

CD8 T lymphocytes do not express cytotoxic proteins in coronary artery aneurysms in acute Kawasaki disease.

Coronary arterial inflammation in acute Kawasaki disease (KD) is characterized by transmural infiltration of CD8 T lymphocytes, suggesting that CD8 T lymphocyte cytotoxic activity may be important in the pathogenesis of coronary arterial damage in acute KD. We performed immunohistochemistry for the cytotoxic proteins perforin and granzyme B on paraffin-embedded, formalin-fixed coronary artery aneurysm tissue from 6 children who died in the acute stage of KD. Neither perforin nor granzyme B was detected in the KD coronary aneurysm wall. We speculate that the etiologic agent of KD interferes with expression of these cytotoxic proteins by CD8 T lymphocytes, prolonging inflammation in the arterial wall and leading to coronary artery aneurysm formation.