Kawasaki Disease in the Time of COVID-19 and MIS-C - The International Kawasaki Disease Registry.

BACKGROUND: Patients with Multisystem Inflammatory Syndrome in Children (MIS-C) and Kawasaki disease (KD) have overlapping clinical features. We compared demographics/clinical presentation, management, and outcomes of patients by evidence of prior SARS-CoV-2 infection. METHODS: The International KD Registry (IKDR) enrolled KD and MIS-C patients from sites from North, Central and South America, Europe, Asia and Middle East. Evidence of prior infection was defined as: Positive (+ve household contact or positive PCR/serology), Possible (suggestive clinical features of MIS-C and/or KD with negative PCR or serology but not both), Negative (negative PCR and serology and no known exposure), and Unknown (incomplete testing and no known exposure). RESULTS: Of 2345 enrolled patients SARS-CoV-2 status was Positive for 1541 (66%) patients, Possible 89 (4%), Negative 404 (17%) and Unknown for 311 (13%) patients. Clinical outcomes varied significantly between the groups, with more patients in the Positive/Possible groups presenting with shock, having admission to Intensive Care, receiving inotropic support, and having longer hospital stays. Regarding cardiac abnormalities, patients in the Positive/Possible groups had a higher prevalence of left ventricular dysfunction, while patients in the Negative and Unknown groups had more severe coronary artery abnormalities. results CONCLUSION: : There appears to be a spectrum of clinical features from MIS-C to KD with a great deal of heterogeneity, and one primary differentiating factor is evidence for prior acute SARS CoV2 infection/exposure. SARS-CoV-2 Positive/Possible patients had more severe presentations and required more intensive management, with a greater likelihood of ventricular dysfunction but less severe coronary artery adverse outcomes, in keeping with MIS-C.

Paediatric inflammatory multisystem syndrome in Canada: population-based surveillance and role of SARS-CoV-2 linkage.

BACKGROUND: Paediatric inflammatory multisystem syndrome (PIMS) is a rare condition temporally associated with SARS-CoV-2 infection. Using national surveillance data, we compare presenting features and outcomes among children hospitalized with PIMS by SARS-CoV-2 linkage, and identify risk factors for intensive care (ICU). METHODS: Cases were reported to the Canadian Paediatric Surveillance Program by a network of >2800 pediatricians between March 2020 and May 2021. Patients with positive versus negative SARS-CoV-2 linkages were compared, with positive linkage defined as any positive molecular or serologic test or close contact with confirmed COVID-19. ICU risk factors were identified with multivariable modified Poisson regression. RESULTS: We identified 406 children hospitalized with PIMS, including 49.8% with positive SARS-CoV-2 linkages, 26.1% with negative linkages, and 24.1% with unknown linkages. The median age was 5.4 years (IQR 2.5-9.8), 60% were male, and 83% had no comorbidities. Compared to cases with negative linkages, children with positive linkages experienced more cardiac involvement (58.8% vs. 37.4%; p < 0.001), gastrointestinal symptoms (88.6% vs. 63.2%; p < 0.001), and shock (60.9% vs. 16.0%; p < 0.001). Children aged ≥6 years and those with positive linkages were more likely to require ICU. CONCLUSIONS: Although rare, 30% of PIMS hospitalizations required ICU or respiratory/hemodynamic support, particularly those with positive SARS-CoV-2 linkages. IMPACT: We describe 406 children hospitalized with paediatric inflammatory multisystem syndrome (PIMS) using nationwide surveillance data, the largest study of PIMS in Canada to date. Our surveillance case definition of PIMS did not require a history of SARS-CoV-2 exposure, and we therefore describe associations of SARS-CoV-2 linkages on clinical features and outcomes of children with PIMS. Children with positive SARS-CoV-2 linkages were older, had more gastrointestinal and cardiac involvement, and hyperinflammatory laboratory picture. Although PIMS is rare, one-third required admission to intensive care, with the greatest risk amongst those aged ≥6 years and those with a SARS-CoV-2 linkage.

Emerging Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome Associated With COVID-19 in Children.

Multisystem inflammatory syndrome in children (MIS-C) has emerged as a rare delayed hyperinflammatory response to SARS-CoV-2 infection and causes severe morbidity in the pediatric age group. Although MIS-C shares many clinical similarities to Kawasaki disease (KD), important differences in epidemiologic, clinical, immunologic, and potentially genetic factors exist and suggest potential differences in pathophysiology and points to be explored and explained. Epidemiologic features include male predominance, peak age of 6 to12 years, and specific racial or ethnicity predilections. MIS-C is characterized by fever, prominent gastrointestinal symptoms, mucocutaneous manifestations, respiratory symptoms, and neurologic complaints, and patients often present with shock. Cardiac complications are frequent and include ventricular dysfunction, valvular regurgitation, pericardial effusion, coronary artery dilation and aneurysms, conduction abnormalities, and arrhythmias. Emerging evidence regarding potential immunologic mechanisms suggest that an exaggerated T-cell response to a superantigen on the SARS-CoV-2 spike glycoprotein-as well as the formation of autoantibodies against cardiovascular, gastrointestinal, and endothelial antigens-are major contributors to the inflammatory milieu of MIS-C. Further studies are needed to determine both shared and distinct immunologic pathway(s) that underlie the pathogenesis of MIS-C vs both acute SARS-CoV-2 infection and KD. There is evidence to suggest that the rare risk of more benign mRNA vaccine-associated myopericarditis is outweighed by a reduced risk of more severe MIS-C. In the current review, we synthesize the published literature to describe associated factors and potential mechanisms regarding an increased risk of MIS-C and cardiac complications, provide insights into the underlying immunologic pathophysiology, and define similarities and differences with KD.

COVID-19 Positive Versus Negative Complete Kawasaki Disease: A Study from the International Kawasaki Disease Registry.

To determine clinical differences for children with complete Kawasaki disease (KD) with and without evidence of preceding SARS-CoV-2 infection. From January 2020, contemporaneous patients with complete KD criteria were classified as either SARS-CoV-2 positive (KDCOVID+; confirmed household exposure, positive PCR and/or serology) or SARS-CoV-2 negative (KDCOVID-; negative testing and no exposure) and compared. Of 744 patients in the International Kawasaki Disease Registry, 52 were KDCOVID- and 61 were KDCOVID+. KDCOVID+ patients were older (median 5.5 vs. 3.7 years; p < 0.001), and all additionally met diagnostic criteria for multisystem inflammatory syndrome in children (MIS-C). They were more likely to have abdominal pain (60% vs. 35%; p = 0.008) and headache (38% vs. 10%; p < 0.001) and had significantly higher CRP, troponin, and BUN/creatinine, and lower hemoglobin, platelets, and lymphocytes. KDCOVID+ patients were more likely to have shock (41% vs. 6%; p < 0.001), ICU admission (62% vs. 10%; p < 0.001), lower left ventricular ejection fraction (mean lowest LVEF 53% vs. 60%; p < 0.001), and to have received inotropic support (60% vs. 10%; p < 0.001). Both groups received IVIG (2 doses in 22% vs. 18%; p = 0.63), but KDCOVID+ were more likely to have received steroids (85% vs. 35%; p < 0.001) and anakinra (60% vs. 10%; p = 0.002). KDCOVID- patients were more likely to have medium/large coronary artery aneurysms (CAA, 12% vs. 0%; p = 0.01). KDCOVID+ patients differ from KDCOVID-, have more severe disease, and greater evidence of myocardial involvement and cardiovascular dysfunction rather than CAA. These patients may be a distinct KD phenotype in the presence of a prevalent specific trigger.

Review of MIS-C Clinical Protocols and Diagnostic Pathways:Towards a Consensus Algorithm

Background The emergence of Multisystem Inflammatory Syndrome in Children (MIS-C) during the SARS-CoV-2 pandemic led to the development of institutional clinical pathways based on expert opinion. We assessed North American pediatric centers’ adaptation to MIS-C and analysed the degree of agreement between algorithms on tiered clinical investigations. Methods This study evaluated MIS-C diagnostic algorithms from 50 tertiary centers developed between May 2020 and December 2021 in the United States and Canada obtained online and through colleagues in various institutions. Descriptive statistics were used to analyse results. Results All clinical pathways used a tiered approach and most required COVID-19 polymerase chain reaction testing on presentation. Over one quarter used a 24-hour fever to initiate investigations and another quarter used 3 days. Basic biochemical work up was performed in all centers on presentation (complete blood count, inflammatory markers, hepatic and renal functions). Specialized investigation was generally reserved for secondary testing (cardiac biomarkers, electrocardiogram and echo, and coagulation panel). Institutions were divided on several investigations for tier distribution, including urine studies, blood cultures, chest radiograph and SARS-CoV-19 serology. Subspecialty consultations were reserved for second-line testing, including cardiology, infectious disease, and rheumatology. Finally, we propose a composite algorithm representative of the consulted pathways. Conclusions Faced with an unprecedented clinical challenge, pediatric institutions responded swiftly with evaluation standardization, adapting to evolving knowledge. Most pathways agreed on initial basic screening tests followed by secondary workup including cardiac investigations. These protocols, developed during a high level of uncertainty, require comparative assessment on efficacy and superiority.

Kawasaki Disease Shock Syndrome vs Classical Kawasaki Disease: A Meta-analysis and Comparison With SARS-CoV-2 Multisystem Inflammatory Syndrome.

BACKGROUND: The emergence of increasing reports worldwide of a severe inflammatory process and shock in pediatric patients resembling Kawasaki disease (KD)-and, more specifically, Kawasaki disease shock syndrome (KDSS)-prompted us to explore KDSS in a preamble of a systematic comparison between the 2 conditions. METHODS: We completed a systematic review of KDSS and performed a meta-analysis comparison between reported KDSS cases and KD controls. RESULTS: A total of 10 case-control series were included in the meta-analysis. Patients with KDSS were older (38.4 ± 30.6 vs 21.9 ± 19.5 months; P < 0.001) compared with standard KD with equal sex distribution and completeness of clinical diagnostic criteria. KDSS present higher C-reactive protein (59.4 ± 29.2 mg/dL vs 20.8 ± 14.8 mg/dL; P < 0.001), lower albumin (2.7 ± 0.5 g/dL vs 3.3 ± 0.5 g/dL; P < 0.01), and lower platelets (255 ± 149 109/L vs 394 ± 132 109/L; P < 0.001) but only borderline higher white blood cells (P = 0.06). Differences in alanine transaminase, aspartate aminotransferase, and erythrocyte sedimentation rate were nonsignificant. The odds of intravenous immunoglobulin resistance (44.4% vs 9.6%; (P < 0.001) and the hospital length of stay (10.9 ± 5.8 vs 5.0 ± 3.0 days; P < 0.001) were higher in KDSS, as were the odds of coronary-artery abnormalities (33.9% vs 8.6%; P < 0.001). CONCLUSIONS: This first meta-analysis on KDSS vs KD represents a basis for future works on KDSS and opens the opportunity for future multicentre studies in the search of causal relationships between presenting elements and the eventual complications of KDSS. The similarities between SARS-CoV-2 multisystem inflammatory syndrome in children and KDSS open new horizons to the understanding of the etiology and pathophysiology related to KDSS.

Myocarditis and Pericarditis After COVID-19 mRNA Vaccination: Practical Considerations for Care Providers.

The mRNA vaccines against COVID-19 infection have been effective in reducing the number of symptomatic cases worldwide. With widespread uptake, case series of vaccine-related myocarditis/pericarditis have been reported, particularly in adolescents and young adults. Men tend to be affected with greater frequency, and symptom onset is usually within 1 week after vaccination. Clinical course appears to be mild in most cases. On the basis of the available evidence, we highlight a clinical framework to guide providers on how to assess, investigate, diagnose, and report suspected and confirmed cases. In any patient with highly suggestive symptoms temporally related to COVID-19 mRNA vaccination, standardized workup includes serum troponin measurement and polymerase chain reaction testing for COVID-19 infection, routine additional lab work, and a 12-lead electrocardiogram. Echocardiography is recommended as the imaging modality of choice for patients with unexplained troponin elevation and/or pathologic electrocardiogram changes. Cardiovascular specialist consultation and hospitalization should be considered on the basis of the results of standard investigations. Treatment is largely supportive, and myocarditis/pericarditis that is diagnosed according to defined clinical criteria should be reported to public health authorities in every jurisdiction. Finally, we recommend COVID-19 vaccination in all individuals in accordance with the Health Canada and National Advisory Committee on Immunization guidelines. In patients with suspected myocarditis/pericarditis after the first dose of an mRNA vaccine, deferral of a second dose is recommended until additional reports become available.

Management of Multisystem Inflammatory Syndrome in Children Associated With COVID-19: A Survey From the International Kawasaki Disease Registry.

BACKGROUND: Since April 2020, there have been numerous reports of children presenting with systemic inflammation, often in critical condition, and with evidence of recent infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This condition, since defined as the multisystem inflammatory syndrome in children (MIS-C), is assumed to be a delayed immune response to coronavirus disease 2019 (COVID-19), and there are frequently cardiac manifestations of ventricular dysfunction and/or coronary artery dilation. METHODS: We surveyed the inpatient MIS-C management approaches of the members of the International Kawasaki Disease Registry across 38 institutions and 11 countries. RESULTS: Among the respondents, 56% reported using immunomodulatory treatment for all MIS-C patients, regardless of presentation. Every respondent reported use of intravenous immunoglobulin (IVIG), including 53% administering IVIG in all patients. Steroids were most often used for patients with severe clinical presentation or lack of response to IVIG, and only a minority used steroids in all patients (14%). Acetylsalicylic acid was frequently used among respondents (91%), including anti-inflammatory and/or antiplatelet dosing. Respondents reported use of prophylactic anticoagulation, especially in patients at higher risk for venous thromboembolism, and therapeutic anticoagulation, particularly for patients with giant coronary artery aneurysms. CONCLUSIONS: There is variation in management of MIS-C patients, with suboptimal evidence to assess superiority of the various treatments; evidence-based gaps in knowledge should be addressed through worldwide collaboration to optimize treatment strategies.

CONTEXTE: Depuis avril 2020, de nombreux cas d'enfants présentant une inflammation généralisée, se trouvant souvent dans un état critique et montrant des signes d'une infection récente au coronavirus du syndrome respiratoire aigu sévère 2 (SRAS-CoV-2), ont été signalés. On pense que cet état, désigné depuis sous le nom de syndrome inflammatoire multisystémique de l'enfant (SIME), pourrait être une réponse immunitaire tardive au virus de la maladie à coronavirus 2019 (COVID-19); les patients présentent souvent des manifestations cardiaques associées à une dysfonction ventriculaire ou à une dilatation des artères coronaires. MÉTHODOLOGIE: Nous avons mené un sondage sur les stratégies de prise en charge du SIME en milieu hospitalier auprès des membres du registre international de la maladie de Kawasaki, qui sont rattachés à 38 établissements répartis dans 11 pays. RÉSULTATS: Au total, 56 % des répondants ont déclaré opter pour un traitement immunomodulateur pour tous les patients présentant un SIME, quelles qu'en soient les manifestations. Tous les répondants ont déclaré avoir recours à l'administration d'immunoglobulines par voie intraveineuse, 53 % d'entre eux utilisant ce traitement chez tous les patients. Les stéroïdes étaient plus souvent utilisés chez les patients présentant des symptômes cliniques graves ou ne répondant pas aux immunoglobulines administrées par voie intraveineuse; seule une minorité de répondants ont déclaré utiliser des stéroïdes chez tous les patients (14 %). Les répondants utilisaient aussi fréquemment l'acide acétylsalicylique (91 %), à des doses anti-inflammatoires ou antiplaquettaires. Ils ont en outre déclaré avoir recours à des anticoagulants en prophylaxie, en particulier chez les patients présentant un risque élevé de thromboembolie veineuse, et à une anticoagulothérapie chez les patients présentant des anévrismes coronaires géants. CONCLUSIONS: La prise en charge des patients présentant un SIME varie d'un médecin à l'autre, et les données permettant d'évaluer la supériorité des divers traitements employés sont insuffisantes; il conviendrait donc de mettre en place des initiatives de collaboration afin de combler les lacunes des connaissances et d'optimiser les stratégies thérapeutiques.