Multisystem Inflammatory Syndrome In Children Research Articles

Mortality and its correlation with diagnostic tests and treatment modalities in multisystem inflammatory syndrome in children admitted in tertiary care hospital of North India

Background: The present study aimed to describe mortality and its correlation with diagnostic tests and treatment modalities among children admitted as a case multisystem inflammatory syndrome in children (MIS-C) in Indira Gandhi Medical College, Shimla. Materials and Methods: We conducted a cross-sectional study for MIS-C from January to July 2021, in the pediatric ward of a tertiary care hospital in North India. All children admitted with the diagnosis of MIS-C were included in the study. Data regarding sociodemographic factors and mortality were extracted and analyzed using Epi Info V7 software. Results: In the present study, a total of 31 children admitted as a case of MIS-C were included in the study. Of these, 23 (74.2%) were discharged after full recovery, 5 (16.1%) died during treatment, and 3 (9.7%) left the hospital against medical advice. Children presenting with severe illness, acidosis, azotemia, Hb<10gm%, Leukocytosis, abnormal RFTs, lipid profile, thrombocytopenia, deranged coagulogram, abnormal ECG, required pediatric intensive care, inotropic support, IVIG, Aspirin, LMWH, had a shorter hospital stay and a higher mortality. Statistical significance was seen with deranged renal function, thrombocytopenia, abnormal ECG, use of LMWH, and respiratory support. Conclusion: Mortality was significantly higher in children having shorter hospital stay <1 week, presenting with severe illness and deranged RFTs, thrombocytopenia, abnormal ECG, and requiring respiratory support, ventilatory support, and taking LMWH.

Assessing autonomic activity and prognostic risk factors comparing multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis.

In pediatric multisystem inflammatory syndrome and isolated viral myocarditis/myopericarditis, autonomic nervous system function can be evaluated by a non-invasive method called heart rate variability. This study aims to evaluate heart rate variability in these two groups by comparing them with each other. This is the first study assessing these values in these two groups of patients. Patients who are diagnosed with multisystem inflammatory syndrome in children and isolated viral myocarditis/myopericarditis at a university hospital from September 2021 to February 2023 are screened by electrocardiography, echocardiography, and 24-hour Holter monitoring. A healthy control group, compatible in age and gender with the patient groups, was selected from healthy subjects that applied to the hospital for palpitation, murmur, and/or chest pain. Heart rate variability parameters and related laboratory markers were analyzed and compared among the three groups. There were 30 patients with multisystem inflammatory syndrome in children, 43 patients with isolated viral myocarditis/myopericarditis, and 109 participants in the healthy control group. Statistically significant differences were found in most of the heart rate variability parameters: standard deviation of normal to normal intervals (SDNN), the mean of the 5- minute RR interval standard deviations (SDNNİ), the standard deviation of 5-minute R wave to R wave(RR) interval means (SDANN), the root mean square of successive RR interval differences (RMSSD), and the percentage of the beats with a consecutive RR interval difference of more than 50 ms (pNN50%), very low frequency, high frequency, low frequency, triangular index, and low frequency/high-frequency ratio. Multisystem inflammatory syndrome in children patients had impaired and declined heart rate variability values compared to the other two groups. In patients with myocarditis/myopericarditis, we couldn't find a significant difference in these parameters with the control group. Heart rate variability can be used as an important non-invasive autonomic function parameter in determining prognosis and treatment plans, especially in patients diagnosed with multisystem inflammatory syndrome in children. This impairment of autonomic activity could be more prominent in patients with decreased left ventricular systolic functions.

Impact of "Long Covid" on Children: Global and Hong Kong Perspectives.

The coronavirus disease (COVID-19) pandemic spares no nation or city, and the virus is responsible for the escalating incidence and mortality worldwide. This article reviews the impact of "Long Covid" on Children. A PubMed search was conducted in December 2021 in Clinical Queries using the key terms "COVID-19" OR "long COVID". The search was restricted to children and adolescent aged < 18 years and English literature. Many large-scale studies have provided strong scientific evidence as to the detrimental and irreversible sequelae of COVID-19 on the health, psychology, and development of affected children. Many insights into managing this disease can be obtained from comparing the management of influenza. COVID-19 is generally a mild respiratory disease in children. Several syndromes, such as multisystem inflammatory syndrome in children (MIS-C) and COVID toe, are probably not specific to SARS-CoV-2. "Long COVID", or the long-term effects of SARS-CoV-2 infection, or the prolonged isolation and containment strategies on education and psychosocial influences on children associated with the pandemic, are significant. Healthcare providers must be aware of the potential effects of quarantine on children's mental health. More importantly, healthcare providers must appreciate the importance of the decisions and actions made by governments, non-governmental organizations, the community, schools, and parents in reducing the possible effects of this situation. Multifaceted age-specific and developmentally appropriate strategies must be adopted by healthcare authorities to lessen the negative impact of quarantine on the psychological well-being of children.

404 - Reported case of recurrence of fever in a patient with multisystem inflammatory syndrome in children due to COVID-19 infection after initial successful treatment

404 - Reported case of recurrence of fever in a patient with multisystem inflammatory syndrome in children due to COVID-19 infection after initial successful treatment

Advances in researches on long coronavirus disease in children: a narrative review.

In the context of the global pandemic of coronavirus disease 2019 (COVID-19), more than 700 million infections and millions of deaths have occurred in countries around the world. Currently, two main sequelae of this disease are considered to occur in children, namely, multi-system inflammatory syndrome in children and long COVID. Among these two, the incidence of long COVID is higher and its impact on the population is more extensive, which is the focus of us. However, due to the lack of relevant studies and the limitations of most studies, the studies on sequelae of COVID-19 infection lag behind those of adults, but they have begun to attract the attention of some clinicians and researchers. We aim to summarize the current knowledge of long COVID in children, helping pediatricians and researchers to better understand this disease and providing guidance on research and clinical treatment of it. We reviewed all the studies on "long COVID", pediatric, children, adolescent, post-COVID syndrome in PubMed published after 2019. This review summarizes the latest researches on epidemiology, pathogenesis, clinical manifestations, prevention and treatment of long COVID in children. Based on the existing research data, we summarized and analyzed the characteristics of long COVID in children, discovering the means to decipher the diagnosis of COVID-19 in children and some potential therapeutic treatments. We aim to summarize existing research on long COVID in children and help pediatricians and government agencies quickly understand the disease so that it can be used for clinical diagnosis, treatment and prevention in the population. In addition, providing a research basis for further researches on the cellular and even molecular level to explain the occurrence and development of diseases, and has a guiding role for future research direction.

Emergency Myelopoiesis Distinguishes Multisystem Inflammatory Syndrome in Children From Pediatric Severe Coronavirus Disease 2019.

Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory condition caused by recent infection with severe acute respiratory syndrome coronavirus 2, but the underlying immunological mechanisms driving this distinct syndrome are unknown. We utilized high-dimensional flow cytometry, cell-free (cf) DNA, and cytokine and chemokine profiling to identify mechanisms of critical illness distinguishing MIS-C from severe acute coronavirus disease 2019 (SAC). Compared to SAC, MIS-C patients demonstrated profound innate immune cell death and features of emergency myelopoiesis (EM), an understudied phenomenon observed in severe inflammation. EM signatures were characterized by fewer mature myeloid cells in the periphery and decreased expression of HLA-DR and CD86 on antigen-presenting cells. Interleukin 27 (IL-27), a cytokine known to drive hematopoietic stem cells toward EM, was increased in MIS-C, and correlated with immature cell signatures in MIS-C. Upon recovery, EM signatures decreased and IL-27 plasma levels returned to normal levels. Despite profound lymphopenia, we report a lack of cfDNA released by adaptive immune cells and increased CCR7 expression on T cells indicative of egress out of peripheral blood. Immune cell signatures of EM combined with elevated innate immune cell-derived cfDNA levels distinguish MIS-C from SAC in children and provide mechanistic insight into dysregulated immunity contributing toward MIS-C, offering potential diagnostic and therapeutic targets.

PECULIARITIES OF THE CORONAVIRUS INFECTION CLINICAL COURSE CAUSED BY SARS-COV2 IN CHILDREN POPULATION (LITERARY REVIEW)

The coronavirus SARS has been known since 2002. In 2019 the rapid spread of the virusSARS-CoV-2 caused a global pandemic. The article provides an analysis of informationon the origin and structure of the virus, discusses the epidemiological aspects ofcoronavirus infection and the main links of pathogenesis, describes data on the mainclinical manifestations of SARS-CoV-2 in children and the long-term consequences ofthe disease, such as multisystem inflammatory syndrome in children and adolescents(MIS-C), focused attention on diagnostic tools, methods of treatment and prevention.The purpose – to analyze and summarize information about the peculiarities of thecourse of the coronavirus infection caused by the SARS-CoV-2 virus among children, itsepidemiological characteristics and means of prevention.Conclusions. 1. Knowledge of the epidemiological and clinical features of the novelcoronavirus disease COVID-19 in the child population needs constant updating, as manyaspects of the clinical course of infection in children remain unclear. 2. CoV-2 affectschildren less frequently and less aggressively than adults, with very low mortality, whichmay be due to a rarer exposure to major sources of transmission (e. g. nosocomial) anda predisposition to significantly milder disease symptoms. 3. Laboratory and radiologicalfindings in sick children with symptoms are mostly non-specific, but they can help identifypatients in severe conditions. 4. Due to mutations of the virus, scientific studies of theclinical and pathogenetic features of the course and prevention of COVID-19 continue,because the consequences of the transferred disease require further study. 5. Vaccinationof children today is one of the important preventive measures to prevent the complicatedcourse of acute respiratory disease associated with SARS-CoV-2.

Clinical prediction model: Multisystem inflammatory syndrome in children versus Kawasaki disease.

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious complication of severe acute respiratory syndrome coronavirus 2 infection. Features of MIS-C overlap with those of Kawasaki disease (KD). The study objective was to develop a prediction model to assist with this diagnostic dilemma. Data from a retrospective cohort of children hospitalized with KD before the coronavirus disease 2019 pandemic were compared to a prospective cohort of children hospitalized with MIS-C. A bootstrapped backwards selection process was used to develop a logistic regression model predicting the probability of MIS-C diagnosis. A nomogram was created for application to individual patients. Compared to children with incomplete and complete KD (N = 602), children with MIS-C (N = 105) were older and had longer hospitalizations; more frequent intensive care unit admissions and vasopressor use; lower white blood cell count, lymphocyte count, erythrocyte sedimentation rate, platelet count, sodium, and alanine aminotransferase; and higher hemoglobin and C-reactive protein (CRP) at admission. Left ventricular dysfunction was more frequent in patients with MIS-C, whereas coronary abnormalities were more common in those with KD. The final prediction model included age, sodium, platelet count, alanine aminotransferase, reduction in left ventricular ejection fraction, and CRP. The model exhibited good discrimination with AUC 0.96 (95% confidence interval: [0.94-0.98]) and was well calibrated (optimism-corrected intercept of -0.020 and slope of 0.99). A diagnostic prediction model utilizing admission information provides excellent discrimination between MIS-C and KD. This model may be useful for diagnosis of MIS-C but requires external validation.

Sex-specific differences in systemic immune responses in MIS-C children

Multisystem Inflammatory Syndrome in Children (MIS-C) is a rare manifestation of Severe Acute Respiratory Syndrome-CoronaVirus-2 (SARS-CoV-2) infection that can result in increased morbidity and mortality. Mounting evidence describes sex disparities in the clinical outcomes of coronavirus disease 2019 (COVID-19). However, there is a lack of information on sex-specific differences in immune responses in MIS-C. This study is an observational and cross-sectional study and we wanted to examine immune parameters such as cytokines, chemokines, acute phase proteins (APPs), growth factors, microbial translocation markers (MTMs), complement components and matrix metalloproteinases (MMPs) in MIS-C children, based on sex. Male children were associated with heightened levels of pro-inflammatory cytokines—IFNγ, IL-2, TNFα, IL-1α, IL-1β, IL-6, IL-12, G-CSF and GM-CSF, chemokines-CCL2, CCL11, CXCL1, CXCL8 and CXCL10, acute phase proteins-α-2M, CRP, growth factors VEGF and TGFα, microbial translocation markers- iFABP, LBP, EndoCAb, complement components—C1q, MBL and C3 and matrix metalloproteinases MMP-8 and MMP-9 compared to female children with MIS-C. These results indicate that the heightened immune response in males is a characteristic feature of MIS-C. These findings might explain the differential disease pathogenesis in males compared to females with MIS-C and facilitate a deeper understanding of this disease.

Long-Term Microvascular Changes in Multisystem Inflammatory Syndrome in Children

This case-control study investigates changes in microcirculation and endothelial function in the acute phase of multisystem inflammatory syndrome in children and 3 to 6 months after onset.

COVID-19 Vaccine Acceptance Among Parents of Children With Multisystem Inflammatory Syndrome in Children.

Data on COVID-19 vaccine acceptability among parents of children with multisystem inflammatory syndrome (MIS-C) are limited. In this cohort of children with MIS-C, enrolled in the Swissped RECOVERY trial (NCT04826588), comparing intravenous immunoglobulins or methylprednisolone, who, in accordance with Swiss guidelines, were recommended for SARS-CoV-2 vaccination, 65% (73/112) of parents reported being vaccinated against SARS-CoV-2 before the MIS-C, while 70% were vaccinated after the MIS-C episode of their child. None of the children were vaccinated before the occurrence of the MIS-C, and only 9% (5/56) received the COVID-19 vaccine after the MIS-C. The predominant barriers to COVID-19 vaccination were concerns over potential side effects and insufficient support from their doctors. This emphasizes the crucial role of health care providers in promoting COVID-19 vaccination among children.

Multisystem inflammatory syndrome in children (MIS-C): A nationwide collaborative study in the Greek population

Multisystem inflammatory syndrome in children (MIS-C) is a rare but severe hyperinflammatory condition that may occur following SARS-CoV-2 infection. This retrospective, descriptive study of children hospitalized with multisystem inflammatory syndrome in children (MIS-C) in 12 tertiary care centers from 3/11/2020 to 12/31/2021. Demographics, clinical and laboratory characteristics, treatment and outcomes are described. Among 145 patients (95 males, median age 8.2 years) included, 123 met the WHO criteria for MIS-C, while 112 (77%) had serological evidence of SARS-CoV-2 infection. Fever was present in 99%, gastrointestinal symptoms in 77%, mucocutaneous involvement in 68% and respiratory symptoms in 28%. Fifty-five patients (38%) developed myocarditis, 29 (20%) pericarditis and 19 (13%) coronary aneurysms. Among the above cases 11/55 (20%), 1/29 (3.4%) and 5/19 (26.3%), respectively, cardiac complications had not fully resolved at discharge. Underlying comorbidities were reported in 18%. Median CRP value was 155 mg/l, ferritin 535 ng/ml, PCT 1.6 ng/ml and WBC 14.2 × 109/mm3. Most patients had elevated troponin (41.3%) and/or NT-pro-BNP (49.6%). Intravenous immunoglobulin plus corticosteroids were used in 117/145 (80.6%), monotherapy with IVIG alone in 13/145 (8.9%) and with corticosteroids alone in 2/145 (1.3%). Anti-IL1 treatment was added in 15 patients (10.3%). Thirty-three patients (23%) were admitted to the PICU, 14% developed shock and 1 required ECMO. Mortality rate was 0.68%. The incidence of MIS-C was estimated at 0.69/1000 SARS-CoV-2 infections. Patients who presented with shock had higher levels of NT-pro-BNP compared to those who did not (p < 0.001). Acute kidney injury and/or myocarditis were associated with higher risk of developing shock. Conclusion: MIS-C is a novel, infrequent but serious disease entity. Cardiac manifestations included myocarditis and pericarditis, which resolved in most patients before discharge. Timely initiation of immunomodulatory therapy was shown to be effective. NT-pro-BNP levels may provide a better prediction and monitoring of the disease course. Further research is required to elucidate the pathogenesis, risk factors and optimal management, and long-term outcomes of this clinical entity.What is Known:• MIS-C is an infrequent but serious disease entity.• Patients with MIS-C present with multi-organ dysfunction, primarily involving the gastrointestinal and cardiovascular systems.What is New:• NT-pro-BNP levels may provide a better prediction and monitoring of the disease course.• Acute kidney injury and/or myocarditis were associated with higher risk of developing shock.

Overview of COVID-19 Infection, Treatment, and Prevention in Children.

Coronavirus disease 2019 (COVID-19), caused by the novel respiratory virus-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-was declared a global pandemic by the World Health Organization on 11 March 2020. Since then, substantial gains have been made in our understanding of COVID-19 epidemiology, disease presentation, and management. While children tend to have less severe disease courses compared to adults, children can still develop severe COVID-19 infections, particularly in those with underlying medical conditions such as obesity, chronic lung disease, or prematurity. In addition, children are at risk of severe complications of COVID-19 infection, such as multisystem inflammatory syndrome in children (MIS-C) or long COVID. The case definitions of MIS-C and long COVID have continued to evolve with the increased understanding of these new entities; however, improved methods of diagnosis and determination of the optimal management are still needed. Furthermore, with the continued circulation of SARS-CoV-2 variants, there remains a need for clinicians to remain up-to-date on the latest treatment and prevention options. The purpose of this review is to provide an evidence-based review of what we have learned about COVID-19 in children since the start of the pandemic and how best to counsel children and their families on the best methods of prevention.

Late presentation of multisystem inflammatory syndrome in children associated with SARS-CoV-2 infection, Kawasaki disease, pancarditis, and great vessels arteritis.

Late presentation of multisystem inflammatory syndrome in children associated with SARS-CoV-2 infection, Kawasaki disease, pancarditis, and great vessels arteritis.

Resurgence of influenza A after SARS-CoV-2 omicron wave and comparative analysis of hospitalized children with COVID-19 and influenza A virus infection.

The highly infectious Omicron variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have caused large-scale transmission from Dec 2022 to Feb 2023 in China. After this event, a remarkable surge of influenza A (Flu A) occurred from March to May 2023, especially in pediatric patients. This study aimed to investigate the differences between pediatric patients infected with COVID-19 Omicron and Flu A virus. A total of 1,063 hospitalized children who admitted into two tertiary general hospital of Guangdong province of China were included. Medical records were compared retrospectively in these patients during the pandemic periods of SARS-CoV-2 omicron and Flu A. A total of 592 Patients with Flu A were mostly preschool and school-aged (>3y, 76.0%), they showed higher ratio of high fever (≥39°C), cough, rhinorrhea, and vomiting than patients with SARS-CoV-2 omicron. Most of the 471 Omicron patients were young children (0-3y, 74.5%) and had more poor appetite and dyspnea symptom. Benign acute children myositis (BACM) was only observed in patients with Flu A, and a significant male predominance. Multisystem inflammatory syndrome in children (MIS-C) was only found in patients with SARS-CoV-2 Omicron. Compared to the SARS-CoV-2 Omicron group, for both age groups (0-3 years and > 3 years), the Flu A group showed significantly reduced lymphocyte (Lym) counts (P < 0.001), and elevated levels of aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and creatinine kinase-MB (CK-MB) in laboratory indexes (all P < 0.001). Additionally, it was found that more children hospitalized with COVID-19 had increased C-reactive protein (CRP) levels compared to those with Flu A. Influenza A infections have notably surged in children, coinciding with the relaxation of COVID-19 related social restrictions. During the epidemic periods of Omicron and Flu A virus infection, different clinical and laboratory characteristics were observed in hospitalized children.

Short-term and medium-term clinical outcomes of multisystem inflammatory syndrome in children: a prospective observational cohort study

BackgroundEven though the incidence of Multisystem Inflammatory Syndrome in children (MIS-C) is decreasing cases are still reported across the world. Studying the consequences of MIS-C enhances our understanding of the disease’s prognosis. The objective of this study was to assess short- and medium-term clinical outcomes of MIS-C.MethodsProspective observational cohort study at Municipal Children’s Hospital Morozovskaya, Moscow, Russia. All children meeting the Royal College of Paediatrics and Child Health (RCPCH), Centers for Disease Control and Prevention (CDC), or the World Health Organization (WHO) MIS-C case definition admitted to the hospital between 17 May and 26 October 2020 were included in the study. All survivors were invited to attend a clinic at 2 and 6 weeks after hospital discharge.Results37 children median age 6 years (interquartile range [IQR] 3.3–9.4), 59.5% (22/37) boys were included in the study. 48.6% (18/37) of patients required ICU care. One child died. All children had increased levels of systemic inflammatory markers during the acute event. Echocardiographic investigations identified abnormal findings in 35.1% (13/37) of children. 5.6% (2/36) of children were presenting with any symptoms six weeks after discharge. By six weeks the inflammatory markers were within the reference norms in all children. The echocardiographic evaluation showed persistent coronary dilatation in one child.ConclusionsDespite the severity of their acute MIS-C, the majority of children in our cohort fully recovered with none having elevated laboratory markers of inflammation at 6 weeks, few (< 10%) reporting persistent symptoms at 6 weeks, and only one with persistent echocardiographic abnormalities.

Multisystem Inflammatory Syndrome in Children during the COVID-19 Pandemic: A Review of Clinical Manifestations, Cardiac Complications and Medical Management.

The SARS-CoV-2 pandemic has led to widespread research on associated clinical syndromes. While pediatric patients were initially deemed as a low-risk population for severe COVID-related disease, an increasing number of case reports have revealed a rare but potentially life-threatening syndrome, multisystem inflammatory syndrome in children (MIS-C). MIS-C is hypothesized to be due to hyperactivation of the immune system via a cytokine storm which leads to end-organ damage via endothelial dysfunction and changes in vascular permeability. Laboratory studies have displayed increased inflammatory markers such as C-reactive protein, erythrocyte sedimentation rate, D-dimer, tumor necrosis factor-alpha, and various interleukins. Studies have reported a wide range of clinical manifestations, including but not limited to fever, hypotension, shock, rash, coagulopathy, and gastrointestinal distress. Cardiac imaging and screening tests have revealed several complications, such as left ventricular failure, arrhythmias, and pericardial effusions. Medical management of MIS-C and cardiac sequelae have included supportive care, intravenous immunoglobulins, and corticosteroids, as well as immunomodulators, monoclonal antibodies, aspirin, and therapeutic anticoagulation, which have prevented serious outcomes in the majority of pediatric patients. Future multicenter and large-scale research is required for precise risk-stratification of MIS-C as well as long-term monitoring of sequelae. In this review, we aim to (1) outline the laboratory findings and clinical manifestations of MIS-C, and (2) describe cardiac complications and medical management of MIS-C.

Clinical analysis of 11 cases multisystem inflammatory syndrome associated with SARS-CoV-2 Omicron variant infection in children

Objective: To explore the clinical characteristics, diagnosis, treatment, and follow-up of multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 Omicron variant infection. Methods: A retrospective analysis was conducted on clinical data of 11 children with MIS-C, who were admitted to the Department of Pediatrics of Peking University First Hospital from December 2022 to January 2023. Clinical characteristics, treatment, and follow-up of MIS-C were summarized in this study. Results: The 11 cases contained 7 boys and 4 girls, with an age of 4.4 (2.0, 5.5) years on admission. All the patients had fever, with a duration of 7(5, 9) days. Other clinical manifestations included rash in 7 cases, conjunctival hyperemia in 5 cases, red lips and raspberry tongue in 3 cases, lymphadenopathy in 3 cases, and swollen fingers and toes in 2 cases. There were 8 cases of digestive symptoms, 8 cases of respiratory symptoms, and 3 cases of nervous system symptoms. Eight patients had multi-system injuries, and one of them had shock presentation. All 11 patients were infected with SARS-CoV-2 Omicron BF.7 variant. The laboratory examination results showed that all cases had elevated inflammatory indicators, abnormal coagulation function and myocardial damage. Six patients had elevated white blood cell counts, 5 cases had liver function abnormalities, 3 cases had kidney function abnormalities, and 8 cases had coronary artery involvement. All 11 patients received anti-infection treatment, of which 3 cases received only 2 g/kg intravenous immunoglobulin (IVIG), while the remaining 8 cases received a combination of IVIG and 2 mg/(kg·d) methylprednisolone. Among the 8 cases with coronary artery disease, 6 cases received low molecular weight heparin anticoagulation therapy. All patients were followed up in 2 weeks after being discharged, and their inflammatory markers had returned to normal by that time. The 8 cases with coronary artery disease and 3 cases with pneumonia showed significant improvement or back to normal at the 4-week follow-up. All patients had no new complications or comorbidities during follow-up of more than 3 months. Conclusions: MIS-C may present with Kawasaki disease-like symptoms, with or without gastrointestinal, neurological, or respiratory symptoms. Elevated inflammatory markers, abnormal coagulation function, and cardiac injury contribute to the diagnosis of MIS-C. IVIG and methylprednisolone were the primary treatments for MIS-C, and a favorable short-term prognosis was observed during a follow-up period of more than 3 months.

Cell-free DNA reveals distinct pathology of multisystem inflammatory syndrome in children.

Cell-free DNA reveals distinct pathology of multisystem inflammatory syndrome in children.

Updated Case Definition of MIS-C and Implications for Clinical Care.

A broad, surveillance case definition was implemented when multisystem inflammatory syndrome in children (MIS-C) emerged in 2020. In 2023, a revised MIS-C case definition was constructed to improve specificity and reduce misclassification with other pediatric inflammatory conditions. This study aims to describe the impact of the updated definition on the classification of patients with MIS-C and Kawasaki Disease (KD). Patients hospitalized from March 2020 to November 2022 with clinician-diagnosed KD and MIS-C at a single center were studied retrospectively. Specificity and positive predictive value were assessed; McNemar test was used to compare specificity. Among 119 patients with MIS-C per the 2020 definition, 20 (17%) did not fulfill the 2023 definition. Six of these 20 (30%) had shock or cardiac involvement. Of 59 KD patients, 10 (17%) met the 2020 MIS-C definition. Five patients (8%) met the 2023 MIS-C definition. Specificity for the 2020 and 2023 MIS-C definitions among KD patients were 83.1% and 91.5% respectively (McNemar, P = .0736). Positive predictive value was higher for the 2023 MIS-C case definition compared with the 2020 MIS-C case definition (95.2% vs 92.2%). Approximately 1 in 5 patients diagnosed with MIS-C using the 2020 case definition did not meet the 2023 definition, including patients with cardiovascular dysfunction. Overlap persisted between patients meeting KD and 2023 MIS-C case definitions, with a false positive rate of 8%. Implications for treatment should be considered, particularly in settings where presumed MIS-C may be treated with corticosteroid monotherapy.