Multisystem Inflammatory Syndrome in U.S. Children and Adolescents

Plasma Protein Biomarkers Distinguish Multisystem Inflammatory Syndrome in Children From Other Pediatric Infectious and Inflammatory Diseases

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious hyperinflammatory complication following infection with severe acute respiratory syndrome coronavirus 2. The mechanisms underpinning the pathophysiology of MIS-C are poorly understood. Moreover, clinically distinguishing MIS-C from other childhood infectious and inflammatory conditions, such as Kawasaki disease or severe bacterial and viral infections, is challenging due to overlapping clinical and laboratory features. We aimed to determine a set of plasma protein biomarkers that could discriminate MIS-C from those other diseases.

METHODS

Seven candidate protein biomarkers for MIS-C were selected based on literature and from whole blood RNA sequencing data from patients with MIS-C and other diseases. Plasma concentrations of ARG1, CCL20, CD163, CORIN, CXCL9, PCSK9 and ADAMTS2 were quantified in MIS-C (n = 22), Kawasaki disease (n = 23), definite bacterial (n = 28) and viral (n = 27) disease and healthy controls (n = 8). Logistic regression models were used to determine the discriminatory ability of individual proteins and protein combinations to identify MIS-C and association with severity of illness.

RESULTS

Plasma levels of CD163, CXCL9 and PCSK9 were significantly elevated in MIS-C with a combined area under the receiver operating characteristic curve of 85.7% (95% confidence interval: 76.6%-94.8%) for discriminating MIS-C from other childhood diseases. Lower ARG1 and CORIN plasma levels were significantly associated with severe MIS-C cases requiring inotropes, pediatric intensive care unit admission or with shock.

CONCLUSION

Our findings demonstrate the feasibility of a host protein biomarker signature for MIS-C and may provide new insight into its pathophysiology.

Long-Term effects of COVID-19: a review of current perspectives and mechanistic insights

Although SARS-CoV-2, responsible for COVID-19, is primarily a respiratory infection, a broad spectrum of cardiac, pulmonary, neurologic, and metabolic complications can occur. More than 50 long-term symptoms of COVID-19 have been described, and as many as 80% of patients may develop ≥1 long-term symptom. To summarize current perspectives of long-term sequelae of COVID-19, we conducted a PubMed search describing the long-term cardiovascular, pulmonary, gastrointestinal, and neurologic effects post-SARS-CoV-2 infection and mechanistic insights and risk factors for the above-mentioned sequelae. Emerging risk factors of long-term sequelae include older age (≥65 years), female sex, Black or Asian race, Hispanic ethnicity, and presence of comorbidities. There is an urgent need to better understand ongoing effects of COVID-19. Prospective studies evaluating long-term effects of COVID-19 in all body systems and patient groups will facilitate appropriate management and assess burden of care. Clinicians should ensure patients are followed up and managed appropriately, especially those in at-risk groups. Healthcare systems worldwide need to develop approaches to follow-up and support patients recovering from COVID-19. Surveillance programs can enhance prevention and treatment efforts for those most vulnerable.

Pediatric pulmonary thromboembolism: a 3-year Canadian Pediatric Surveillance Program study

BACKGROUND

Pediatric pulmonary embolism (PE) is a rare event associated with significant morbidity and mortality. Awareness of clinical presentation and practices unique to children may aid clinicians in prompt identification and treatment.

OBJECTIVES

To describe the incidence, risk factors, clinical presentation, diagnostic and therapeutic practices, and short-term outcomes of pediatric PE.

METHODS

We conducted a 3-year national surveillance study through the Canadian Pediatric Surveillance Program. Over 2800 pediatric specialists and subspecialists were contacted monthly from 2020 to 2022 and requested to report all new cases of PE in patients up to 18 years of age. Case-specific data were obtained through voluntary completion of a detailed questionnaire.

RESULTS

Fifty-eight cases (78% female, n = 45) were reported (2.4 cases per million children), with rates highest in adolescents 15 to 18 years (6.6 cases per million). Detailed information, available for 31 (53%) cases, documented at least 1 risk factor in 28 (90%) cases; 24 (77%) patients presented with 2 or more symptoms. Computed tomography pulmonary angiography was used for diagnostic confirmation in 25 (81%) cases. Anticoagulation was initiated in 24 (77%) of 31 cases; fewer than 5 patients underwent thrombolysis or surgical interventions. Of 28 patients who received therapeutic interventions, 8 (29%) experienced treatment-related complications. Fewer than 5 mortalities were reported.

CONCLUSION

Pediatric PE is a rare event, with female adolescents at the highest risk. Although the presentation is often nonspecific, clinicians should maintain a high index of suspicion, particularly in patients with risk factors and when other diagnoses that may explain symptoms have been excluded.

Knowledge framework of intravenous immunoglobulin resistance in the field of Kawasaki disease: A bibliometric analysis (1997-2023)

BACKGROUND

Kawasaki disease (KD) is an autoimmune disease with cardiovascular disease as its main complication, mainly affecting children under 5 years old. KD treatment has made tremendous progress in recent years, but intravenous immunoglobulin (IVIG) resistance remains a major dilemma. Bibliometric analysis had not been used previously to summarize and analyze publications related to IVIG resistance in KD. This study aimed to provide an overview of the knowledge framework and research hotspots in this field through bibliometrics, and provide references for future basic and clinical research.

METHODS

Through bibliometric analysis of relevant literature published on the Web of Science Core Collection (WoSCC) database between 1997 and 2023, we investigated the cooccurrence and collaboration relationships among countries, institutions, journals, and authors and summarized key research topics and hotspots.

RESULTS

Following screening, a total of 364 publications were downloaded, comprising 328 articles and 36 reviews. The number of articles on IVIG resistance increased year on year and the top three most productive countries were China, Japan, and the United States. Frontiers in Pediatrics had the most published articles, and the Journal of Pediatrics had the most citations. IVIG resistance had been studied by 1889 authors, of whom Kuo Ho Chang had published the most papers.

CONCLUSION

Research in the field was focused on risk factors, therapy (atorvastatin, tumor necrosis factor-alpha inhibitors), pathogenesis (gene expression), and similar diseases (multisystem inflammatory syndrome in children, MIS-C). "Treatment," "risk factor," and "prediction" were important keywords, providing a valuable reference for scholars studying this field. We suggest that, in the future, more active international collaborations are carried out to study the pathogenesis of IVIG insensitivity, using high-throughput sequencing technology. We also recommend that machine learning techniques are applied to explore the predictive variables of IVIG resistance.

Gastrointestinal and Hepatic Manifestations of COVID-19 in Children: A Systematic Review and Meta-analysis

Background

Children with COVID-19 may present with gastrointestinal (GI) symptoms and liver dysfunction.

Objective

To determine the type and prevalence of gastrointestinal (GI) and hepatic manifestations of COVID-19 in children and its association with severity of illness.

Methods

A systematic literature search was done from inception until January 4, 2021 using PubMed, Cochrane Library, Google Scholar and prepublication repositories with no language restrictions. Studies that reported the demographic and clinical features of children with COVID-19 and provided data on their GI and hepatic signs and symptoms were included. Prevalence of GI and hepatic manifestations were pooled using Stata14.

Results

We included 58 studies with total of 4497 participants. Overall, one-third of children with COVID-19 presented with at least one GI symptom (33.8%; 95% confidence interval (CI) 23.0, 45.4; I2 97.5%; 42 studies, 3327 participants) with abdominal pain, nausea or vomiting, and diarrhea each occurring in approximately 20%. Children with severe COVID-19 were more likely to present with GI symptoms (odds ratio 2.59; 95% CI 1.35, 4.99; I2 24%; 4 studies, 773 participants). The pooled prevalence of elevated transaminases was 11% for both AST (11.3%, 95% CI 4.9, 19.3; I2 74.7%; 11 studies, 447 participants) and ALT (11.2%, 95% CI 7.1, 16.0; I2 40.8%; 15 studies, 513 participants). Hepatic findings such as jaundice (2-17%), hepatomegaly (2%) or behavioral changes (2%) from hepatic encephalopathy were variably reported by a few studies.The degree of heterogeneity was not improved on exclusion of studies with poor quality, but markedly improved on subgroup analysis according to geographical region and presence of MIS-C. Studies from China showed that children with COVID-19 had significantly lower pooled prevalence for any of the GI symptoms with low degree of heterogeneity, particularly for diarrhea, nausea/vomiting, and abdominal pain, all of which had I2 of 0%. Those with multisystem inflammatory syndrome in children (MIS-C) had significantly more common GI symptoms and increased transaminases than those without.

Conclusion

One-third of children with COVID-19 exhibit at least one GI symptom and more likely present in those with severe disease. Elevated transaminases were present in 10%. Prevalence of GI and hepatic manifestations were higher among children with MIS-C.

The landscape of hot topics and research frontiers in Kawasaki disease: Scientometric analysis

Purpose

Kawasaki disease(KD) is a vascular inflammatory disease that was first identified in 1967. Numerous studies have been conducted on KD and have yielded valuable recent insights. This current bibliometric analysis aimed to determine the intellectual landscape of research interest in KD.

Methods

Publications were collected from the Web of Science Core Collection. Bibliometric tools such as CiteSpace and VOSviewer were utilized to analyze the research focus, emerging trends, frontiers, and hot topics in this specific field.

Results

A total of 6122 articles on KD were retrieved. Pediatric Cardiology, Pediatrics International, and Pediatric Infections Disease Journal were the three most productive journals reporting KD development. The University of California San Diego was the most productive institution, with 230 publications. The USA was the most productive country, with 1661 articles in KD. SARS-CoV-2, diagnostic serum biomarkers, and risk factor prediction models for coronary arterial lesions and subtypes of KD are popular topics in KD research. Factors that induce smooth muscle cell transition to myofibroblastic cell, potentially halting the subacute/chronic vasculitis process and endothelial dysfunction in macrophage activation syndrome associated with KD were the frontiers in the study of KD.

Conclusion

KD has attracted widespread attention worldwide that has continued to increase since 1974. The most productive institution and country are the University of California San Diego and the USA, respectively. SARS-CoV-2, serum biomarkers, and prediction models are hot topics in this field.

Effectiveness of COVID-19 vaccination against school absenteeism in children and adolescents hospitalized with COVID-19

BACKGROUND

COVID-19 vaccination has been recommended for children to protect them and to enable in-person educational and social activities.

METHODS

We estimated COVID-19 vaccination effectiveness (VE) against school absenteeism in children 5-17 years old hospitalized from September 1, 2021 through May 31, 2023. Full vaccination was defined as two vaccine doses.

RESULTS

We studied 231 children admitted to hospital with COVID-19, including 206 (89.2 %) unvaccinated/partially vaccinated and 25 (10.8 %) fully vaccinated. Unvaccinated/partially vaccinated children were absent from school for longer periods compared to fully vaccinated children (median absence: 14 versus 10 days; p-value = 0.05). Multivariable regression showed that full COVID-19 vaccination was associated with fewer days of absence compared to no/partial vaccination on average (adjusted relative risk: 0.77; 95 % CI: 0.61 to 0.98). COVID-19 VE was 50.7 % (95 % CI: -11.3 % to 78.2 %) for school absenteeism above the median duration of absenteeism.

CONCLUSIONS

Full COVID-19 vaccination conferred protection against school absenteeism in hospitalized school-aged children with COVID-19.

The plasma proteome differentiates the multisystem inflammatory syndrome in children (MIS-C) from children with SARS-CoV-2 negative sepsis

BACKGROUND

The Multi-System Inflammatory Syndrome in Children (MIS-C) can develop several weeks after SARS-CoV-2 infection and requires a distinct treatment protocol. Distinguishing MIS-C from SARS-CoV-2 negative sepsis (SCNS) patients is important to quickly institute the correct therapies. We performed targeted proteomics and machine learning analysis to identify novel plasma proteins of MIS-C for early disease recognition.

METHODS

A case-control study comparing the expression of 2,870 unique blood proteins in MIS-C versus SCNS patients, measured using proximity extension assays. The 2,870 proteins were reduced in number with either feature selection alone or with a prior COMBAT-Seq batch effect adjustment. The leading proteins were correlated with demographic and clinical variables. Organ system and cell type expression patterns were analyzed with Natural Language Processing (NLP).

RESULTS

The cohorts were well-balanced for age and sex. Of the 2,870 unique blood proteins, 58 proteins were identified with feature selection (FDR-adjusted P < 0.005, P < 0.0001; accuracy = 0.96, AUC = 1.00, F1 = 0.95), and 15 proteins were identified with a COMBAT-Seq batch effect adjusted feature selection (FDR-adjusted P < 0.05, P < 0.0001; accuracy = 0.92, AUC = 1.00, F1 = 0.89). All of the latter 15 proteins were present in the former 58-protein model. Several proteins were correlated with illness severity scores, length of stay, and interventions (LTA4H, PTN, PPBP, and EGF; P < 0.001). NLP analysis highlighted the multi-system nature of MIS-C, with the 58-protein set expressed in all organ systems; the highest levels of expression were found in the digestive system. The cell types most involved included leukocytes not yet determined, lymphocytes, macrophages, and platelets.

CONCLUSIONS

The plasma proteome of MIS-C patients was distinct from that of SCNS. The key proteins demonstrated expression in all organ systems and most cell types. The unique proteomic signature identified in MIS-C patients could aid future diagnostic and therapeutic advancements, as well as predict hospital length of stays, interventions, and mortality risks.

Treatment of multisystem inflammatory syndrome in children

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C), a relatively uncommon but severe pediatric complication, is associated with coronavirus disease 2019 (COVID-19). A variety of treatment approaches, including intravenous immunoglobulins (IVIGs), glucocorticoids (GCs) and biologic agents, such as anakinra and infliximab, have been described for the management of COVID-19-related MIS-C. Anticoagulant therapy is also important. However, a well-developed treatment system has not been established, and many issues remain controversial. Several recently published articles related to the treatment of MIS-C have been released. Hence, in this review, we identified relevant articles published recently and summarized the treatment of MIS-C more comprehensively and systematically.

DATA SOURCES

We reviewed the literature on the treatment of MIS-C through 20 September 2023. The PubMed/Medline, Web of Science, EMBASE, and Cochrane Library databases were searched with the combination of the terms "multisystem inflammatory syndrome", "MIS-C", "PIMS-TS", "therapy", "treatment", "drug", "IVIG", "GCs", "intravenous immunoglobulin", "corticosteroids", "biological agent", and "aspirin".

RESULTS

The severity of MIS-C varies, and different treatment schemes should be used according to the specific condition. Ongoing research and data collection are vital to better understand the pathophysiology and optimal management of MIS-C.

CONCLUSIONS

MIS-C is a disease involving multiple systems and has great heterogeneity. With the accumulation of additional experience, we have garnered fresh insights into its treatment strategies. However, there remains a critical need for greater standardization in treatment protocols, alongside the pressing necessity for more robust and meticulously conducted studies to deepen our understanding of these protocols. Supplementary file1 (MP4 208044 kb).

Coronary artery dilation in non-hospitalised children with asymptomatic or mild COVID-19

INTRODUCTION

Infection with Sars-CoV-2 is known to cause cardiac injury and coronary artery changes in moderate to severe acute COVID-19 and post-acute multisystem inflammatory syndrome in children (MIS-C). However, little is known about the potential for cardiac involvement, in particular coronary artery dilation, in asymptomatic or mild cases of COVID-19.

METHODS

A retrospective review of children ≤ 18 years of age with a history of asymptomatic or mild COVID-19 disease who underwent echocardiography after Sars-CoV-2 infection is conducted. Patients were excluded if they had been hospitalised for COVID-19/MIS-C or had a history of cardiac disease that could affect coronary artery dimension. Coronary artery dilation was defined as the Boston Z-score greater than 2.0.

RESULTS

One hundred and fifty-seven patients met inclusion criteria with a mean age of 9.4 years (+/- 5.4 years). Eighty-four (54%) patients were identified as having COVID-19 through positive antibody testing. All patients underwent electrocardiogram and echocardiogram as part of their cardiology evaluation. One hundred and thirty-five (86%) patients had a normal evaluation or only a minor variant on electrocardiogram, while 22 patients had abnormalities on echocardiogram, 4 of which demonstrated coronary artery dilation based on the Boston Z-score.

CONCLUSIONS

Much of the literature for post-infectious screening and follow-up focuses on patients with a history of moderate to severe COVID-19 disease, emphasising the need for surveillance for the potential development of myocarditis. In this study, 4 out of 157 (2.5%) children with a history of asymptomatic or mild COVID-19 disease without MIS-C were found to have some degree of coronary artery dilation. The significance of this finding currently remains unknown.

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.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

Myeloid-derived suppressor cells and T cell populations in children with Multisystem Inflammatory Syndrome

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) represents a hyperinflammatory state that can result in multi-organ dysfunction and death. Myeloid-derived suppressor cells (MDSC) are an immunosuppressive cell population that expands under inflammatory conditions and suppresses T cell function. We hypothesized that MDSC would be increased in children with MIS-C and that MDSC expansion would be associated with T cell lymphopenia.

METHODS

We conducted a prospective, observational study. Initial blood samples were collected within 48 h of admission. Age-matched healthy controls underwent sampling once. MDSC and T cell populations were identified by flow cytometric methods.

RESULTS

We enrolled 22 children with MIS-C (12 ICU, 10 ward) and 21 healthy controls (HC). Children with MIS-C demonstrated significantly higher MDSC compared to HC, and MDSC expansion persisted for >3 weeks in the ICU group. Children with MIS-C admitted to the ICU demonstrated significantly lower absolute numbers of T cells and natural killer cells. There were no significant associations between MDSC and cardiac dysfunction, duration of hospitalization, or vasoactive inotrope score.

CONCLUSIONS

Our study suggests that children critically ill with MIS-C have expansion of MDSC and associated decreased T cell and NK cell populations. Our results did not demonstrate associations between MDSC and clinical outcomes.

IMPACT

Multisystem inflammatory syndrome in children (MIS-C) is a dysregulated immune response occurring several weeks after SARS-CoV-2 infection that can result in multi-organ dysfunction and death. Children severely ill with MIS-C demonstrated increased myeloid-derived suppressor cells and decreased absolute numbers of CD4+ and CD8 + T cells and NK cells compared to healthy controls. There was no significant association between MDSC numbers and clinical outcomes; including cardiac dysfunction, length of stay, or requirement of vasoactive support, in children with MIS-C.

Clinical characteristics and outcomes of COVID-19-associated encephalopathy in children

Apart from the typical respiratory symptoms, coronavirus disease 2019 (COVID-19) also affects the central nervous system, leading to central disorders such as encephalopathy and encephalitis. However, knowledge of pediatric COVID-19-associated encephalopathy is limited, particularly regarding specific subtypes of encephalopathy. This study aimed to assess the features of COVID-19-associated encephalopathy/encephalitis in children. We retrospectively analyzed a single cohort of 13 hospitalized children with COVID-19-associated encephalopathy. The primary outcome was the descriptive analysis of the clinical characteristics, magnetic resonance imaging and electroencephalography findings, treatment progression, and outcomes. Thirteen children among a total of 275 (5%) children with confirmed COVID-19 developed associated encephalopathy/encephalitis (median age, 35 months; range, 3-138 months). Autoimmune encephalitis was present in six patients, acute necrotizing encephalopathy in three, epilepsy in three, and central nervous system small-vessel vasculitis in one patient. Eight (62%) children presented with seizures. Six (46%) children exhibited elevated blood inflammatory indicators, cerebrospinal fluid inflammatory indicators, or both. Two (15%) critically ill children presented with multi-organ damage. The magnetic resonance imaging findings varied according to the type of encephalopathy/encephalitis. Electroencephalography revealed a slow background rhythm in all 13 children, often accompanied by epileptic discharges. Three (23%) children with acute necrotizing encephalopathy had poor prognoses despite immunotherapy and other treatments. Ten (77%) children demonstrated good functional recovery without relapse. This study highlights COVID-19 as a new trigger of encephalopathy/encephalitis in children. Autoimmune encephalitis is common, while acute necrotizing encephalopathy can induce poor outcomes. These findings provide valuable insights into the impact of COVID-19 on children's brains.

A Systematic Review and Clinical Presentation of Central Nervous System Complications of Severe Acute Respiratory Syndrome Coronavirus 2 in Hospitalized Pediatric Patients During the Coronavirus Disease 2019 Pandemic in Israel

BACKGROUND

Coronavirus disease-associated central nervous system complications (CNS-C) in hospitalized children, especially during the Omicron wave, and in comparison with influenza associated CNS-C, are not well understood.

METHODS

The study population included 755 children aged <18 years hospitalized with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at Sheba Medical Center, during March 2020 to July 2022. A comparative cohort consisted of 314 pediatric patients with influenza during the 2018-2019 and 2019-2020 influenza seasons.

RESULTS

Overall, 5.8% (n = 44) of patients exhibited CNS-C. Seizures at presentation occurred in 33 patients with COVID-19 (4.4%), with 2.6% (n = 20) experiencing nonfebrile seizures, 1.1% (n = 8) febrile seizures, and 0.7% (n = 5) status epilepticus. More patients with CNS-C experienced seizures during the Omicron wave versus the pre-Omicron period (77.8% vs 41.2%, P = 0.03). Fewer patients were admitted to the intensive care unit in the Omicron wave (7.4%) versus prior waves (7.4% vs 41.2%, P = 0.02). Fewer patients with SARS-CoV-2 experienced CNS-C (5.8%) versus patients with influenza (9.9%), P = 0.03. More patients with SARS-CoV-2 experienced nonfebrile seizures (2.6% vs 0.6%, P = 0.06), whereas more patients with influenza experienced febrile seizures (7.3% vs 1.1%, P < 0.01).

CONCLUSIONS

The Omicron wave was characterized by more seizures and fewer intensive-care-unit admissions than previous waves. Pediatric patients with SARS-CoV-2 experienced fewer CNS-C and more nonfebrile seizures compared with patients with influenza.

Left Atrial Strain in Multisystem Inflammatory Syndrome in Children and Associations with Systemic Inflammation and Cardiac Injury

Multisystem inflammatory syndrome in children (MIS-C) commonly involves cardiac injury with both systolic and diastolic dysfunction. Left atrial strain (LAS) detects subclinical diastolic dysfunction in adults but is infrequently used in children. We evaluated LAS in MIS-C and the associations with systemic inflammation and cardiac injury. In this retrospective cohort study, LAS parameters [reservoir (LAS-r), conduit (LAS-cd), and contractile (LAS-ct)] obtained from admission echocardiograms of MIS-C patients were compared to healthy controls and between MIS-C patients with and without cardiac injury (BNP > 500 pg/ml or troponin-I > 0.04 ng/ml). Correlation and logistic regression analyses were performed to assess LAS associations with admission inflammatory and cardiac biomarkers. Reliability testing was performed. We identified 118 patients with MIS-C and 20 healthy controls. Median LAS parameters were reduced in MIS-C patients compared to controls (LAS-r: 31.8 vs. 43.1%, p < 0.001; LAS-cd: - 28.8 vs. - 34.5%, p = 0.006; LAS-ct: - 5.2 vs. - 9.3%, p < 0.001) and reduced in MIS-C patients with cardiac injury (n = 59) compared to no injury (n = 59) (LAS-r: 29.6 vs. 35.8%, p = 0.001; LAS-cd: - 26.5 vs. - 30.4%, p = 0.036; LAS-ct: - 4.6 vs. - 9.3%, p = 0.008). A discrete LAS-ct peak was absent in 65 (55%) MIS-C patients but present in all controls (p < 0.001). Procalcitonin correlated strongly with averaged E/e' (r = 0.55, p = 0.001). Moderate correlations were found for ESR and LAS-ct (r = - 0.41, p = 0.007) as well as BNP and LAS-r (r = - 0.39, p < 0.001) and LAS-ct (r = 0.31, p = 0.023). Troponin-I had only weak correlations. Intra-rater reliability was good for all LAS parameters, and inter-rater reliability was good to excellent for LAS-r, and fair for LAS-cd and LAS-ct. LAS analysis, particularly the absence of a LAS-ct peak, was reproducible and may be superior to conventional echocardiographic parameters for detecting diastolic dysfunction in MIS-C. No strain parameters on admission were independently associated with cardiac injury.

What the SARS-CoV-2 Pandemic Has Taught Us About Immunosuppression, Vaccinations, and Immune Dysregulation: The Rheumatology Experience

PURPOSE OF REVIEW

This review reflects on the impact of the COVID-19 pandemic on the field of rheumatology, emphasizing resulting insights related to the risks of viral infections in immunosuppressed patients, vaccine immunogenicity in immunocompromised patients, and immune dysregulation in the setting of viral infection.

RECENT FINDINGS

During the pandemic, global patient registries provided real-time insights into the risk factors associated with severe COVID-19 outcomes in rheumatology patients. Updated evidence-based recommendations from the American College of Rheumatology (ACR) guided rheumatology practice during a time of considerable uncertainty. Studies on COVID-19 vaccines in immunocompromised populations enhanced our understanding of specific immunosuppressive therapies on vaccine efficacy. The immune dysregulation seen in severe COVID-19 underscored a role for immunomodulation in this and other severe infections. Furthermore, novel post-infectious conditions, namely multisystem inflammatory syndrome in children (MIS-C) and Long COVID, reshaped our understanding of post-viral syndromes and revealed novel pathological mechanisms. Lessons from the COVID-19 pandemic demonstrate the power of collaborative research. The scientific revelations from this dreadful time will, nonetheless, benefit the practice of rheumatology for years to come.

A bibliometric analysis of Kawasaki disease from 1974 to 2022

Objective

To analyse the research history, development trends and current status of relevant literature in the field of Kawasaki disease, and to provide the basis for future directions in Kawasaki disease (KD) research.

Methods

Literature on Kawasaki disease published between January 1974 and December 2022 was searched for in the Web of Science database, and CiteSpace was used to perform visual analyses.

Results

The search yielded a total of 6950 articles. The number of publications related to Kawasaki disease showed an increasing trend. A collaborative network analysis revealed that the United States, Japan and mainland China were the most influential countries in this field. The University of California system contributed the most publications and the journal with the most publications was Circulation. JW Newburger was an authoritative author in this field. "Coronary artery lesion", "Intravenous immunoglobulin" (IVIG) and "Risk factor" were three prominent keywords. Keyword bursts changed from "TNF" and "IVIG", which focused on aetiology and treatment, to "Long term management", which emphasized the recovery period, and to "Kawasaki-like disease" and "Multisystem inflammatory syndrome" during the novel coronavirus pandemic. Trends of highly cited references indicated that landmark articles in different periods focused on Kawasaki disease guidelines, gene polymorphisms and multisystem inflammatory syndrome caused by the novel coronavirus.

Conclusion

The aetiology of Kawasaki disease remains unclear, but viral infection is likely to play an important role. The combination of evolving sequencing technologies, large-scale epidemiological investigations and prospective cohort studies is likely to be important in exploring Kawasaki disease and improving its prognosis in future.

Cardiac injury progression in children with multisystem inflammatory syndrome associated with SARS-CoV-2 infection: a review

The symptoms and signs of infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are milder in children than in adults. However, in April 2020, British pediatricians first reported that coronavirus disease 2019 (COVID-19) may present as multisystem inflammatory syndrome in children and adolescents (MIS-C), similar to that observed in Kawasaki disease. MIS-C can be associated with multiple systemic injuries and even death in children. In addition to digestive system involvement, cardiac injury is prominent. This article reviews the pathogenesis, clinical manifestations, and treatment of cardiac injury caused by MIS-C, which may help clinicians in early diagnosis and timely commencement of treatment.

Evolution of Cardiovascular Findings in Multisystem Inflammatory Syndrome in Children (MIS-C) Across COVID-19 Variants: Common Trends and Unusual Presentations

Multisystem inflammatory syndrome in children (MIS-C) is a rare condition following COVID-19 infection. Cardiac involvement is common and includes left ventricular systolic dysfunction, cardiac marker elevation, electrocardiogram (ECG) changes, and coronary artery dilation. This single-center retrospective cohort study compares cardiovascular disease between three major SARS-CoV-2 variants and describes the evolution of findings in medium-term follow-up. Of 69 total children (mean age 9.2 years, 58% male), 60 (87%) had cardiovascular involvement with the most common features being troponin elevation in 33 (47%) and left ventricular dysfunction in 22 (32%). Based on presumed infection timing, 61 patients were sorted into variant cohorts of Alpha, Delta, and Omicron. Hospitalization was longer for the Delta group (7.7 days) vs Alpha (5.1 days, p = 0.0065) and Omicron (4.9 days, p = 0.012). Troponin elevation was more common in Delta compared to Alpha (13/20 vs 7/25, p = 0.18), and cumulative evidence of cardiac injury (echocardiographic abnormality and/or troponin elevation) was more common in Delta (17/20) compared with Alpha (12/25, p = 0.013) or Omicron (8/16, p = 0.034). Forty-nine (77%) of the original cohort (n = 69) had no cardiac symptoms or findings beyond 3 months post-hospitalization. Cardiac MRI was performed in 28 patients (between 3 and 6 months post-hospitalization) and was normal in 25 patients (89%). The differences in the variant cohorts may be due to alteration of the immune landscape with higher severity of COVID-19 infection. Despite overall reassuring cardiac outcomes, it is important to note the variability of presentation and remain vigilant with future variants.

Morbidity trend and space-time clusters of COVID-19 occurrence in children and adolescents

OBJECTIVE

To analyze the morbidity trend and space-time distribution clusters of confirmed COVID-19 cases in children and adolescents.

METHOD

An ecological study of COVID-19 cases confirmed in the Information System from 2020 to 2022 in the age group from 0 to 19 years old, residents in Mato Grosso municipalities, Brazilian Midwest region. A trend analysis of the monthly morbidity rate of cases/100,000 inhabitants was used, following Prais-Winsten's regression. A space-time distribution of the Bayesian incidence rate per 100,000 inhabitants was performed, in addition to a space-time scan to identify high-risk clusters.

RESULTS

Of all 79,592 COVID-19 cases studied, 51.6% were in females and 44.21% in people aged 15-19 years old. The mean monthly rate was 265.87 cases per 100,000 inhabitants, with a stationary trend in the period analyzed (Monthly Percentage Variation [MPV]) = 12.15; CI95%[MPV]: -0.73;26.70). The morbidity rate due to COVID-19 was higher in the female gender (283.14/100,000 inhabitants) and in the age group from 15 to 19 years old (485.90/100,000 inhabitants). An increasing trend was observed with a greater monthly time variation of 14.42% (CI95%[MPV]: 1.28;29.28)] among those aged from 10 to 14 years old. The primary cluster, which was also the one with the highest Relative Risk (RR = 5,16, p-value = 0.001), included 19 municipalities located in the North health macro-region.

CONCLUSION

The findings indicated a monthly stationary trend in the study population, an increase in the age group from 10 to 14 years old, and areas at a higher risk for the disease in the North health macro-region of the state.

Multisystem Inflammatory Syndrome in Adults-Related Unstable Angina With Coronary Aneurysm in a Young Female: A Case Report

Multisystem inflammatory syndrome in adults (MIS-A) is a systemic inflammatory disease associated with COVID-19 and follows coronary artery aneurysms similar to Kawasaki disease. In many cases, it is improved by treatments such as high-dose steroids or intravenous immunoglobulin (IVIg). However, the role of untreated coronary artery aneurysms leading to future stenosis remains unknown. Untreated MIS-A may potentially lead to the formation of coronary aneurysms. In cases of COVID-19 where young adults present with angina-like symptoms, an evaluation for angina is considered. Herein, we report a case of a 27-year-old female who developed unstable angina with coronary artery aneurysms six months after COVID-19 infection. She required surgery for unstable angina, which resulted in an improvement in chest pain. Coronary artery lesions are considered to be related to MIS-A, and treatment was conducted in accordance with that for Kawasaki disease. Currently, the pathological differences and prognosis between MIS-A and Kawasaki disease remain unclear, but the elucidation of the conditions is warranted in the future.

Postacute Sequelae of SARS-CoV-2 in Children

The coronavirus disease 2019 (COVID-19) pandemic has caused significant medical, social, and economic impacts globally, both in the short and long term. Although most individuals recover within a few days or weeks from an acute infection, some experience longer lasting effects. Data regarding the postacute sequelae of severe acute respiratory syndrome coronavirus 2 infection (PASC) in children, or long COVID, are only just emerging in the literature. These symptoms and conditions may reflect persistent symptoms from acute infection (eg, cough, headaches, fatigue, and loss of taste and smell), new symptoms like dizziness, or exacerbation of underlying conditions. Children may develop conditions de novo, including postural orthostatic tachycardia syndrome, myalgic encephalomyelitis/chronic fatigue syndrome, autoimmune conditions and multisystem inflammatory syndrome in children. This state-of-the-art narrative review provides a summary of our current knowledge about PASC in children, including prevalence, epidemiology, risk factors, clinical characteristics, underlying mechanisms, and functional outcomes, as well as a conceptual framework for PASC based on the current National Institutes of Health definition. We highlight the pediatric components of the National Institutes of Health-funded Researching COVID to Enhance Recovery Initiative, which seeks to characterize the natural history, mechanisms, and long-term health effects of PASC in children and young adults to inform future treatment and prevention efforts. These initiatives include electronic health record cohorts, which offer rapid assessments at scale with geographical and demographic diversity, as well as longitudinal prospective observational cohorts, to estimate disease burden, illness trajectory, pathobiology, and clinical manifestations and outcomes.

2024 Heart Disease and Stroke Statistics: A Report of US and Global Data From the American Heart Association

BACKGROUND

The American Heart Association (AHA), in conjunction with the National Institutes of Health, annually reports the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, nutrition, sleep, and obesity) and health factors (cholesterol, blood pressure, glucose control, and metabolic syndrome) that contribute to cardiovascular health. The AHA Heart Disease and Stroke Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, brain health, complications of pregnancy, kidney disease, congenital heart disease, rhythm disorders, sudden cardiac arrest, subclinical atherosclerosis, coronary heart disease, cardiomyopathy, heart failure, valvular disease, venous thromboembolism, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The AHA, through its Epidemiology and Prevention Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States and globally to provide the most current information available in the annual Statistical Update with review of published literature through the year before writing. The 2024 AHA Statistical Update is the product of a full year's worth of effort in 2023 by dedicated volunteer clinicians and scientists, committed government professionals, and AHA staff members. The AHA strives to further understand and help heal health problems inflicted by structural racism, a public health crisis that can significantly damage physical and mental health and perpetuate disparities in access to health care, education, income, housing, and several other factors vital to healthy lives. This year's edition includes additional global data, as well as data on the monitoring and benefits of cardiovascular health in the population, with an enhanced focus on health equity across several key domains.

RESULTS

Each of the chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policymakers, media professionals, clinicians, health care administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Effectiveness of Bivalent mRNA COVID-19 Vaccines in Preventing SARS-CoV-2 Infection in Children and Adolescents Aged 5 to 17 Years

Importance

Bivalent mRNA COVID-19 vaccines were recommended in the US for children and adolescents aged 12 years or older on September 1, 2022, and for children aged 5 to 11 years on October 12, 2022; however, data demonstrating the effectiveness of bivalent COVID-19 vaccines are limited.

Objective

To assess the effectiveness of bivalent COVID-19 vaccines against SARS-CoV-2 infection and symptomatic COVID-19 among children and adolescents.

Design, Setting, and Participants

Data for the period September 4, 2022, to January 31, 2023, were combined from 3 prospective US cohort studies (6 sites total) and used to estimate COVID-19 vaccine effectiveness among children and adolescents aged 5 to 17 years. A total of 2959 participants completed periodic surveys (demographics, household characteristics, chronic medical conditions, and COVID-19 symptoms) and submitted weekly self-collected nasal swabs (irrespective of symptoms); participants submitted additional nasal swabs at the onset of any symptoms.

Exposure

Vaccination status was captured from the periodic surveys and supplemented with data from state immunization information systems and electronic medical records.

Main Outcome and Measures

Respiratory swabs were tested for the presence of the SARS-CoV-2 virus using reverse transcriptase-polymerase chain reaction. SARS-CoV-2 infection was defined as a positive test regardless of symptoms. Symptomatic COVID-19 was defined as a positive test and 2 or more COVID-19 symptoms within 7 days of specimen collection. Cox proportional hazards models were used to estimate hazard ratios for SARS-CoV-2 infection and symptomatic COVID-19 among participants who received a bivalent COVID-19 vaccine dose vs participants who received no vaccine or monovalent vaccine doses only. Models were adjusted for age, sex, race, ethnicity, underlying health conditions, prior SARS-CoV-2 infection status, geographic site, proportion of circulating variants by site, and local virus prevalence.

Results

Of the 2959 participants (47.8% were female; median age, 10.6 years [IQR, 8.0-13.2 years]; 64.6% were non-Hispanic White) included in this analysis, 25.4% received a bivalent COVID-19 vaccine dose. During the study period, 426 participants (14.4%) had laboratory-confirmed SARS-CoV-2 infection. Among these 426 participants, 184 (43.2%) had symptomatic COVID-19, 383 (89.9%) were not vaccinated or had received only monovalent COVID-19 vaccine doses (1.38 SARS-CoV-2 infections per 1000 person-days), and 43 (10.1%) had received a bivalent COVID-19 vaccine dose (0.84 SARS-CoV-2 infections per 1000 person-days). Bivalent vaccine effectiveness against SARS-CoV-2 infection was 54.0% (95% CI, 36.6%-69.1%) and vaccine effectiveness against symptomatic COVID-19 was 49.4% (95% CI, 22.2%-70.7%). The median observation time after vaccination was 276 days (IQR, 142-350 days) for participants who received only monovalent COVID-19 vaccine doses vs 50 days (IQR, 27-74 days) for those who received a bivalent COVID-19 vaccine dose.

Conclusion and Relevance

The bivalent COVID-19 vaccines protected children and adolescents against SARS-CoV-2 infection and symptomatic COVID-19. These data demonstrate the benefit of COVID-19 vaccine in children and adolescents. All eligible children and adolescents should remain up to date with recommended COVID-19 vaccinations.

Comparison of Eosinophil Counts in Inflammatory Conditions: Multisystem Inflammatory Syndrome in Children, Kawasaki Disease, and Infectious Mononucleosis

This study examined the distinctions between multisystem inflammatory syndrome associated with coronavirus disease 2019, Kawasaki disease, and infectious mononucleosis. These three inflammatory disorders have commonalities according to clinical and laboratory results, particularly in relation to eosinophil levels. In this retrospective, single-center study, we documented the examination records (acute phase reactants and complete blood count) and clinical and cardiological findings of 130 patients diagnosed with multisystem inflammatory syndrome, Kawasaki disease, and infectious mononucleosis. These patients were treated and received follow-up care in our hospital from March 12, 2020, to September 13, 2022, as per the hospital records. Statistical analyses were performed using NCSS 2007, version 1 software. Eosinopenia was more prevalent in children with multisystem inflammatory syndrome than in those with Kawasaki disease, who showed normal or elevated eosinophil counts. The eosinophil counts in patients with infectious mononucleosis typically fell within the normal range. Our study found no correlation between the eosinophil counts and cardiac involvement in pediatric patients with either condition. These findings indicate a higher prevalence of eosinopenia in patients with multisystem inflammatory syndrome, irrespective of cardiac involvement, than in those with Kawasaki disease. Despite similarities in clinical findings, Kawasaki disease and multisystem inflammatory syndrome in children necessitate further studies for distinct characteristic elucidation.

Assessing pattern of the Pediatric Multisystem Inflammatory Syndrome (PMIS) in children during the COVID-19 pandemic: experience from the emergency department of tertiary care center of a low-middle-income country

BACKGROUND

Pediatric Multisystem Inflammatory Syndrome (PMIS) is a hyperinflammatory condition affecting multiple organs in children, often resembling incomplete Kawasaki Disease during later phases of COVID-19 infection. Data on PMIS in low-middle-income countries, particularly in emergency department settings, is limited.

OBJECTIVES

This prospective observational study at Aga Khan University Hospital, Karachi, aimed to determine the frequency, clinical presentation patterns, and laboratory parameters of children with PMIS visiting the emergency department during the COVID-19 pandemic. Secondary objectives included assessing factors associated with in-hospital mortality.

METHODS

From March 2020 to September 2021, patients meeting World Health Organization PMIS criteria were enrolled. COVID-19 testing included PCR and antibody testing. Data was collected through a questionnaire and analyzed statistically.

RESULTS

Among 56 PMIS patients (85.7% male, mean age 7.67 ± 4.8 years), respiratory symptoms (70%), neurological symptoms (57%), and gastrointestinal symptoms (54%) were common presentations. Signs included delayed capillary refill time (93%), low-volume pulses (89%), and hypotension (68%). COVID-19 antibodies were positive in the majority (78.6%) while PCR was positive in 18%. Risk factors for mortality included prolonged emergency department stay, and high Ferritin and Lactate Dehydrogenase levels.

CONCLUSION

PMIS affects children of all ages. Respiratory and gastrointestinal symptoms are the most frequent presentations. Elevated inflammatory markers, including LDH, Ferritin, D-dimer, and Pro-BNP, correlate with higher mortality risk.

Cardiovascular manifestations and cardiac magnetic resonance follow-up of multisystem inflammatory syndrome in children (MIS-C)

OBJECTIVE

This study aimed to evaluate the cardiovascular manifestations and surveillance of multisystem inflammatory syndrome in children (MIS-C) and to determine the correlation of echocardiographic findings with cardiac magnetic resonance imaging findings.

METHODS

Forty-four children diagnosed as MIS-C with cardiac involvement were enrolled in this observational descriptive study. The diagnosis of MIS-C was made according to the criteria of Centers for Disease Control and Prevention. Clinical findings, laboratory parameters, and electrocardiographic and echocardiographic findings at the time of diagnosis and during follow-up were evaluated. Cardiac magnetic resonance was performed on 28 (64%) cases. The 1-year follow-up imaging was performed in all cases with abnormal initial cardiac magnetic resonance findings.

RESULTS

Forty-four patients (56.8% male) with a mean age of 8.5 ± 4.8 years were enrolled in this study. There was a significant positive correlation between high-sensitivity cardiac troponin T (mean: 162 ± 444.4 pg/ml) and N-terminal pro b-type natriuretic peptide (mean: 10,054 ± 11,604 pg/ml) (p < 0.01). Number of cases with an electrocardiographic and echocardiographic abnormality was 34 (77%) and 31 (70%), respectively. Twelve cases (45%) had left ventricular systolic dysfunction and 14 (32%) cases had pericardial effusion on admission. Three cases (11%) had cardiac magnetic resonance findings that may be attributed to the presence of myocardial inflammation, and pericardial effusion was present in seven (25%) cases. Follow-up cardiac magnetic resonances of all cases were normal. Cardiac abnormalities were completely resolved in all except two cases.

CONCLUSIONS

Myocardial involvement can be seen during acute disease, but MIS-C generally does not lead to prominent damage during a year of surveillance. Cardiac magnetic resonance is a valuable tool to evaluate the degree of myocardial involvement in cases with MIS-C.

One-Year Follow-Up Results of MIS-C Patients with Coronary Artery Involvement: A Multi-center Study

Multisystem inflammatory syndrome (MIS-C) in children is a rare complication of SARS-CoV-2 infection. Knowing the course of the affected or unaffected coronary arteries in the patients under follow-up is important in terms of defining the long-term prognosis of the disease and determining the follow-up plan. This is a multicenter and retrospective study. The data were obtained from nine different centers. Between May 2020 and August 2022, 68 of 790 patients had coronary artery involvement. One-year echocardiographic data of 67 of 789 MIS-C patients with coronary artery involvement were analyzed. Existing pathologies of the coronary arteries were grouped as increased echogenicity, dilatation and aneurysm according to Z scores, and their changes over a 1-year period were determined. The data of all three groups are defined as frequency. SPSS Statistics version 22 was used to evaluate the data. In our study, aneurysm was observed in 16.4%, dilatation in 68.7% and increased echogenicity in 13.4% of the patients. All of the patients with involvement in the form of increased echogenicity recovered without sequelae by the end of the first month. No progression to aneurysm was observed in any of the patients with dilatation. No new-onset involvement was observed in patients with previously healthy coronary arteries during the convalescent period. In addition, from the sixth month follow-up period, there was no worsening in the amount of dilatation in any of the patients. At least 94% of the patients who completed the 12th month control period returned to normal.

Comparing the immune abnormalities in MIS-C to healthy children and those with inflammatory disease reveals distinct inflammatory cytokine production and a monofunctional T cell response

Multisystem inflammatory syndrome in children (MIS-C) is a severe, hyperinflammatory disease that occurs after exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The underlying immune pathology of MIS-C is incompletely understood, with limited data comparing MIS-C to clinically similar paediatric febrile diseases at presentation. SARS-CoV-2-specific T cell responses have not been compared in these groups to assess whether there is a T cell profile unique to MIS-C. In this study, we measured inflammatory cytokine concentration and SARS-CoV-2-specific humoral immunity and T cell responses in children with fever and suspected MIS-C at presentation (n = 83) where MIS-C was ultimately confirmed (n = 58) or another diagnosis was made (n = 25) and healthy children (n = 91). Children with confirmed MIS-C exhibited distinctly elevated serum IL-10, IL-6, and CRP at presentation. No differences were detected in SARS-CoV-2 spike IgG serum concentration, neutralisation capacity, antibody dependant cellular phagocytosis, antibody dependant cellular cytotoxicity or SARS-CoV-2-specific T cell frequency between the groups. Healthy SARS-CoV-2 seropositive children had a higher proportion of polyfunctional SARS-CoV-2-specific CD4+ T cells compared to children with MIS-C and those with other inflammatory or infectious diagnoses, who both presented a largely monofunctional SARS-CoV-2-specific CD4+ T cell profile. Treatment with steroids and/or intravenous immunoglobulins resulted in rapid reduction of inflammatory cytokines but did not affect the SARS-CoV-2-specific IgG or CD4+ T cell responses in MIS-C. In these data, MIS-C had a unique cytokine profile but not a unique SARS-CoV-2 specific humoral or T cell cytokine response.

Outpatient Pediatric Cardiology Follow-Up of Patients with Multisystem Inflammatory Syndrome in Children (MIS-C): A Single-Institution, Medium-Term Follow-Up Study

We are continuing to learn about the multisystem inflammatory syndrome in children (MIS-C) associated with SARS-CoV-2 infection. There are many published studies regarding the acute management of MIS-C; however, there is still much to learn regarding the long-term outcomes of patients with MIS-C. In this study, we report the outcomes of patients admitted at our institution with MIS-C and the follow-up practices in Pediatric Cardiology over the last three years. We included patients who were admitted at Lucile Packard Children's Hospital between January 1, 2020 and October 31, 2022, who met the CDC criteria for MIS-C, and were followed in the Pediatric Cardiology Outpatient Clinic at our institution. There were 25 patients who met our inclusion criteria. Eighteen patients (72%) had their initial follow-up visit within 1-2 weeks of discharge and seven patients (28%) had their initial follow-up visit within 4-6 weeks of discharge. Six patients out of the 25 (24%) had decreased left ventricular ejection fraction (LVEF < 50%) during their hospitalization. No patients had left main coronary artery aneurysm (z-score > 2.5), two patients (8%) had proximal right coronary artery aneurysm (z-score > 2.5), and one patient (4%) had left anterior descending coronary artery aneurysm (z-score > 2.5) during hospitalization. Patients who were admitted with the diagnosis of MIS-C showed normalization of left ventricular dysfunction at their initial follow-up visit as early as 2-4 weeks after discharge. In this cohort of MIS-C patients, a 4-6-week window for the first follow-up visit after discharge seems reasonable.

Elevation of IL-17 Cytokines Distinguishes Kawasaki Disease From Other Pediatric Inflammatory Disorders

OBJECTIVE

Kawasaki disease (KD) is a systemic vasculitis of young children that can lead to development of coronary artery aneurysms. We aimed to identify diagnostic markers to distinguish KD from other pediatric inflammatory diseases.

METHODS

We used the proximity extension assay to profile proinflammatory mediators in plasma samples from healthy pediatric controls (n = 30), febrile controls (n = 26), and patients with KD (n = 23), multisystem inflammatory syndrome in children (MIS-C; n = 25), macrophage activation syndrome (n = 13), systemic and nonsystemic juvenile idiopathic arthritis (n = 14 and n = 10, respectively), and juvenile dermatomyositis (n = 9). We validated the key findings using serum samples from additional patients with KD (n = 37) and febrile controls (n = 28).

RESULTS

High-fidelity proteomic profiling revealed distinct patterns of cytokine and chemokine expression across pediatric inflammatory diseases. Although KD and MIS-C exhibited many similarities, KD differed from MIS-C and other febrile diseases in that most patients exhibited elevation in one or more members of the interleukin-17 (IL-17) cytokine family, IL-17A, IL-17C, and IL-17F. IL-17A was particularly sensitive and specific, discriminating KD from febrile controls with an area under the receiver operator characteristic curve of 0.95 (95% confidence interval 0.89-1.00) in the derivation set and 0.91 (0.85-0.98) in the validation set. Elevation of all three IL-17-family cytokines was observed in over 50% of KD patients, including 19 of 20 with coronary artery aneurysms, but was rare in all other comparator groups.

CONCLUSION

Elevation of IL-17 family cytokines is a hallmark of KD and may help distinguish KD from its clinical mimics.

Elevated High-Sensitivity Troponin and NT-proBNP Values in Febrile Children

OBJECTIVES

The COVID-19 pandemic and subsequent rise of multisystem inflammatory syndrome in children have raised interest in high-sensitivity troponin (hs-TnT) and N-terminal probrain natriuretic peptide (NT-proBNP) because these have been found to be elevated in many cases of multisystem inflammatory syndrome in children. Our aim was to study hs-TnT and NT-proBNP concentrations in febrile children not affected by COVID-19.

METHODS

We retrospectively measured cardiac markers, hs-TnT, and NT-proBNP in leftover blood samples of febrile children (0-18 years) diagnosed and treated in a single-center emergency department (ED) (N = 67) and pediatric intensive care unit (PICU) (N = 19) that participated in a multicenter, prospective study of infection biomarkers (PERFORM).

RESULTS

Concentrations of hs-TnT, median 1.8 ng/L (interquartile range [IQR], 0.0-15.1), and NT-proBNP, 194 pg/mL (IQR, 54.9-706), were higher in febrile children than in controls (N = 25, hs-TnT 0.0 [IQR, 0-0]; NT-proBNP 56.3 [IQR, 29.7-109], both P < 0.001), whereas PICU patients had higher concentrations (hs-TnT 15.1 [IQR, 10.3-102] and NT-proBNP 828 [IQR, 657-4712], both P < 0.001) than ED patients (hs-TnT 0 [IQR, 0-7.4] and NT-proBNP 104 [IQR, 39.5-363]). No differences were found between viral and bacterial infections. Highest concentrations were found in children with either comorbidity predisposing to elevated concentrations (eg, chronic cardiac or renal disease) or children with critical illness or multiorgan failure such as those with septic shock.

CONCLUSIONS

Concentrations of hs-TnT and NT-proBNP are often elevated in febrile children with different causes of fever. Concentrations were higher in children admitted to the PICU than in children attending the ED, and seem to reflect disease severity rather than the underlying cause of fever.

Features of Appendix and the Characteristics of Appendicitis Development in Children with COVID-19

BACKGROUND

Research on the subject of the influence of SARS-CoV-2 mechanisms on human homeostasis remains an actual problem. Particular interest is the study of pathomorphological changes in the appendix in children with COVID-19.

OBJECTIVES

Aim of this study: morphological and molecular biological evaluation of the appendix in children of different age groups with COVID-19.

METHODS

Groups were formed on the basis of anamnestic, clinical, and morphological data: I (n = 42; aged 2 to 18 years, average age-10.8 ± 4.79)-with an established clinical diagnosis: coronavirus infection (COVID-19; PCR+); II (n = 55; aged 2 to 18 years, average age-9.7 ± 4.77)-with a confirmed clinical diagnosis of acute appendicitis; collected before the onset of the COVID-19 pandemic in 2017-2019; and III (n = 38; aged 2 to 18 years, average age-10.3 ± 4.62)-the control group. Histological and immunohistochemical studies were conducted using primary antibodies to CD3, CD4, CD68, CD163, CD20, and CD138 and to pro-inflammatory (IL-1, IL-6) and anti-inflammatory (IL-4, IL-10) cytokines.

RESULTS

In most samples of appendixes in children with COVID-19, signs of destructive phlegmonous-ulcerative and gangrenous appendicitis were discovered. An increase in CD3+, CD4+, CD68+, CD163+, and CD20+ CD138+ immunocompetent cells was found in the appendix of children with COVID-19. As well, there was an increase in pro-inflammatory (IL-1, IL-6) and anti-inflammatory (IL-4, IL-10) cytokines.

CONCLUSIONS

The aforementioned pathological and immunohistochemical changes were more pronounced in the group of children aged 6-12 years (childhood).

Using HScore for Evaluation of Hemophagocytosis in Multisystem Inflammatory Syndrome Associated with COVID-19 in Children

Hemophagocytic syndrome is a key point in the pathogenesis of severe forms of multisystem inflammatory syndrome associated with COVID-19 in children (MIS-C). The factors associated with hemophagocytosis in patients with MIS-C were assessed in the present study of 94 boys and 64 girls ranging in age from 4 months to 17 years, each of whose HScore was calculated. In accordance with a previous analysis, patients with HScore ≤ 91 (n = 79) and HScore > 91 (n = 79) were compared. Patients with HScore > 91 had a higher frequency of symptoms such as cervical lymphadenopathy, dry cracked lips, bright mucous, erythema/swelling of hands and feet, peeling of fingers, edematous syndrome, hepatomegaly, splenomegaly, and hypotension/shock. They also had a higher erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and D-dimer levels, and a tendency to anemia, thrombocytopenia, and hypofibrinogenemia. They more often needed acetylsalicylic acid and biological treatment and were admitted to ICU in 70.9% of cases. Conclusion: The following signs of severe MIS-C were associated with HScore > 91: myocardial involvement, pericarditis, hypotension/shock, and ICU admission.

New insight into the intravenous immunoglobulin treatment in Multisystem Inflammatory Syndrome in children and adults

Within 6 months of the coronavirus pandemic, a new disease entity associated with a multisystem hyperinflammation syndrome as a result of a previous infection with the SARS-CoV-2 virus is increasingly being identified in children termed Multisystem Inflammatory Syndrome in Children (MIS-C) and more recently in adults(MIS-A). Due to its clinical similarity with Kawasaki Disease, some institutions have used intravenous immunoglobulins and steroids as first line agents in the management of the disease. We seek to find how effective intravenous immunoglobulin therapy is across these two disease entities. A comprehensive English literature search was conducted across PubMed, MEDLINE, and EMBASE databases using the keywords multisystem inflammatory syndrome in children/adults and treatment. All major online libraries concerning the diagnosis and treatment of MIS-C and MIS-A were searched. Relevant papers were read, reviewed, and analyzed. The use of intravenous immunoglobulins (IVIG) and steroids for the treatment of multisystemic inflammatory syndrome in children(MIS-C) is well established and recommended by multiple pediatric governing institutions. However, there is still no optimal treatment guideline or consensus on the use of IVIG in adults. The use of IVIG in both the child and adult populations may lower the risk of treatment failure and the need for adjunctive immunomodulatory therapy. Despite the promising results of IVIG use for the management of MIS-C and MIS-A, considering the pathophysiological differences between MIS-C and MIS-A, healthcare professionals need to further assess the differences in disease risk and treatment. The optimal dose, frequency, and duration of treatment are still unknown, more research is needed to establish treatment guidelines.

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.

[Multisystem inflammatory syndrome in children in the context of coronavirus disease 2019 pandemic]

Multisystem inflammatory syndrome in children (MIS-C) is a complex syndrome characterized by multi-organ involvement that has emerged in the context of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak. The clinical presentation of MIS-C is similar to Kawasaki disease but predominantly presents with fever and gastrointestinal symptoms, and severe cases can involve toxic shock and cardiac dysfunction. Epidemiological findings indicate that the majority of MIS-C patients test positive for SARS-CoV-2 antibodies. The pathogenesis and pathophysiology of MIS-C remain unclear, though immune dysregulation following SARS-CoV-2 infection is considered a major contributing factor. Current treatment approaches for MIS-C primarily involve intravenous immunoglobulin therapy and symptomatic supportive care. This review article provides a comprehensive overview of the definition, epidemiology, pathogenesis, clinical presentation, diagnosis, treatment, and prognosis of MIS-C.

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.

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

BACKGROUND

Even 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.

METHODS

Prospective 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.

RESULTS

37 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.

CONCLUSIONS

Despite 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 (MIS-C) of a toddler initially presenting with fever and pyuria

We report a case of multisystem inflammatory syndrome in children (MIS-C) in an East Asian toddler. He presented with a 2-day history of fever and pyuria, 5 weeks before that he had recovered from COVID-19. He was initially treated as urinary tract infection. On day 5 of fever, he was noted to have bilateral non-suppurative limbus-sparing conjunctivitis, red and cracked lips and erythematous extremities. Investigations showed raised inflammatory markers (C-reactive protein and erythrocyte sedimentation rate), thrombocytopenia and a markedly elevated NT-proBNP. He received prompt and appropriate treatment inpatient; however, he still had mild coronary abnormalities at 9 months postdischarge. The aim of this paper is to describe the initial presentation and progress of a case of MIS-C. The unique features of this case are his initial presentation of pyuria and notably, his demography (young age, East Asian) which is more typical of Kawasaki disease than MIS-C.

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.

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 according to evidence of previous SARS-CoV-2 infection.

METHODS

The International Kawasaki Disease Registry (IKDR) enrolled KD and MIS-C patients from sites in North, Central, and South America, Europe, Asia, and the Middle East. Evidence of previous infection was defined as: Positive (household contact or positive polymerase chain reaction [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 for 89 (4%), Negative for 404 (17%) and Unknown for 311 (13%). Clinical outcomes varied significantly among 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, and patients in the Negative and Unknown groups had more severe coronary artery abnormalities.

CONCLUSIONS

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 previous acute SARS-CoV-2 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.

COVID-19-Related Multi-systemic Inflammatory Syndrome in Children (MIS-C)

Multisystem inflammatory syndrome in children (MIS-C) is a severe complication of SARS-CoV-2 infections in children. This syndrome manifests about a month after the initial viral infection and is characterized by fever, multiorgan dysfunction, and systemic inflammation. This chapter will review the emergence, epidemiology, clinical characteristics, diagnosis, pathophysiology, immunomodulatory treatment, prognosis, outcomes, and prevention of MIS-C. While the pathophysiology of MIS-C remains to be defined, it is a post-infection, hyperinflammatory syndrome of childhood with elevated inflammatory cytokines.

Emerging and re-emerging pediatric viral diseases: a continuing global challenge

The twenty-first century has been marked by a surge in viral epidemics and pandemics, highlighting the global health challenge posed by emerging and re-emerging pediatric viral diseases. This review article explores the complex dynamics contributing to this challenge, including climate change, globalization, socio-economic interconnectedness, geopolitical tensions, vaccine hesitancy, misinformation, and disparities in access to healthcare resources. Understanding the interactions between the environment, socioeconomics, and health is crucial for effectively addressing current and future outbreaks. This scoping review focuses on emerging and re-emerging viral infectious diseases, with an emphasis on pediatric vulnerability. It highlights the urgent need for prevention, preparedness, and response efforts, particularly in resource-limited communities disproportionately affected by climate change and spillover events. Adopting a One Health/Planetary Health approach, which integrates human, animal, and ecosystem health, can enhance equity and resilience in global communities. IMPACT: We provide a scoping review of emerging and re-emerging viral threats to global pediatric populations This review provides an update on current pediatric viral threats in the context of the COVID-19 pandemic This review aims to sensitize clinicians, epidemiologists, public health practitioners, and policy stakeholders/decision-makers to the role these viral diseases have in persistent pediatric morbidity and mortality.

Interaction Between Genetic Susceptibility and COVID-19 Pathogenesis in Pediatric Multisystem Inflammatory Disorders: The Role of Immune Responses

Numerous studies have highlighted the emergence of coronavirus disease (COVID-19) symptoms reminiscent of Kawasaki disease in children, including fever, heightened multisystem inflammation, and multiorgan involvement, posing a life-threatening complication. Consequently, extensive research endeavors in pediatric have aimed to elucidate the intricate relationship between COVID-19 infection and the immune system. COVID-19 profoundly impacts immune cells, culminating in a cytokine storm that particularly inflicts damage on the pulmonary system. The gravity and vulnerability to COVID-19 are closely intertwined with the vigor of the immune response. In this context, the human leukocyte antigen (HLA) molecule assumes pivotal significance in shaping immune responses. Genetic scrutiny of HLA has unveiled the presence of at least one deleterious allele in children afflicted with multisystem inflammatory syndrome in children (MIS-C). Furthermore, research has demonstrated that COVID-19 exploits the angiotensin-converting enzyme 2 (ACE-2) receptor, transmembrane serine protease type 2, and various other genes to gain entry into host cells, with individuals harboring ACE-2 polymorphisms being at higher risk. Pediatric studies have employed diverse genetic methodologies, such as genome-wide association studies (GWAS) and whole exome sequencing, to scrutinize target genes. These investigations have pinpointed two specific genomic loci linked to the severity and susceptibility of COVID-19, with the HLA locus emerging as a notable risk factor. In this comprehensive review article, we endeavor to assess the available evidence and consolidate data, offering insights into current clinical practices and delineating avenues for future research. Our objective is to advance early diagnosis, stabilization, and appropriate management strategies to mitigate genetic susceptibility's impact on the incidence of COVID-19 in pediatric patients with multisystem inflammation.

Multisystem Inflammatory Syndrome in Children (MIS-C) in a Low-income Country: What Treatment Should be Adopted in Case of a Lack of Immunoglobulin?

INTRODUCTION

In multisystem inflammatory syndrome (MIS-C), children typically present high-grade fever, gastrointestinal symptoms, Kawasaki-like symptoms, and even a toxic shock-like syndrome days to weeks after recovering from SARS-CoV-2 infection. It is important to raise awareness of this condition in order to have early diagnosis and immediate treatment of patients. We have, herein, reported 44 cases of MIS-C with various risk factors and symptoms. Furthermore, we have emphasized the efficacy of experience in treating children with MIS-C with high-dose corticosteroids as an alternative to immunoglobulin in low-income countries.

METHODS

We conducted a targeted survey of MIS-C from early May 2020 to October 2022 on 44 children and adolescents with characteristics of multisystem inflammatory syndrome admitted to the pediatric department of the university hospital center in Oujda, Morocco, to which patients diagnosed with MIS-C were referred. The case definition included six criteria: serious illness leading to hospitalization, age under 18 years, fever of at least 24 hours, laboratory evidence of inflammation, multi-organ involvement, biological inflammatory syndrome, and evidence of coronavirus infection based on polymerase chain reaction, antibody testing or exposure to people with COVID-19 in the past month. The criteria used to diagnose myocarditis were impaired left ventricular function, central mitral leak, and elevation of BNP or pro-BNP. Coronary involvement was assessed by the z-score and the criteria for its presence was a z-score equal to or greater than 2.5.

RESULTS

Our study included 44 children and adolescents with MIS-C in our hospital, with male predominance (79%) and a median age of six years. Cardiovascular involvement was present in 91%, mucocutaneous in 78%, gastrointestinal in 70%, hematologic in 84%, and respiratory in 2% of patients. Coronary abnormalities (z-score ≥ 2.5) were documented in 21 cases (48%). Glucocorticoids were frequently used in comparison to immunoglobulin, which were uncommonly available and expensive.

CONCLUSION

The therapeutic protocol that was adopted was high doses of short-term prednisone (Cortancyl) at 4mg/kg/day for 4 days. Favorable outcome was noted in all patients over a 2-year period.

Criteria for Cytokine Storm Syndromes

In the past two decades, there has been a great deal of work aimed to devise diagnostic guidelines, classification criteria, and diagnostic scores for cytokine storm syndromes (CSSs). The most notable effort has been the large-scale multinational study that led to the development of the 2016 classification criteria for macrophage activation syndrome (MAS) complicating systemic juvenile idiopathic arthritis (JIA). Future studies should scrutinize the validity of the proposed criteria, particularly in systemic JIA patients treated with biologics, in children with subtle or incomplete forms of MAS, and in patients with MAS complicating other rheumatologic disorders. More generic CSS criteria are also available but often lack sensitivity and specificity in a wide variety of patient populations and CSSs of different etiologies. The coronavirus disease 2019 (COVID-19)-related lung disease led to an evolution of the concept of a "cytokine storm." Emerging and unsolved challenges in the diagnosis of the different forms of CSSs highlight the need for diagnostic tools and well-established classification criteria to enable timely recognition and correct classification of patients.