Severe COVID-19 multisystem inflammatory syndrome versus severe dengue in children from Indonesia: a cross-sectional study.

INTRODUCTION: Severe multisystem inflammatory syndrome in children (MIS-C) and severe dengue are challenging to identify during the COVID-19 pandemic in dengue-endemic areas. Fever, multiorgan involvement, and shock characterize both severe MIS-C and severe dengue. Distinguishing between the two diseases is beneficial in initiating proper management. METHODS: Medical records of children < 18 years old who were hospitalized at Hasan Sadikin General Hospital's PICU between December 2020 and July 2022 with severe MIS-C or severe dengue were recorded. Differences were assessed using comparative and descriptive analyses. RESULTS: Seventeen severe dengue patients and 4 severe MIS-C were included. The average age of severe MIS-C was 11.5 years (SD ± 2.9, 95% CI), and that of severe dengue patients was 6.2 years (SD ± 4.4, 95% CI) (p value = 0.034, 95%). Fever and abdominal pain were the most common symptoms in both groups (p = 0.471, 95% CI). Rash (p = 0.049) and nonpurulent conjunctivitis (p = 0.035) were two symptoms with significant differences. The highest platelet count (p-value = 0.006, 95% CI), AST (p-value = 0.026, 95% CI), and D-dimer level (p-value = 0.025, 95% CI) were significantly different between the two cohorts. Cardiac abnormalities were found in all (100%) severe MIS-C patients, but only one (5.9%) in severe dengue patients. CONCLUSION: Age, rash, nonpurulent conjunctivitis, platelet count, AST and D-dimer level may distinguish severe MIS-C from severe dengue fever.

Severity predictors for multisystemic inflammatory syndrome in children after SARS-CoV-2 infection in Vietnam.

Multisystemic inflammatory syndrome in children (MIS-C) might manifest in a broad spectrum of clinical scenarios, ranging from mild features to multi-organ dysfunction and mortality. However, this novel entity has a heterogenicity of data regarding prognostic factors associated with severe outcomes. The present study aimed to identify independent predictors for severity by using multivariate regression models. A total of 391 patients (255 boys and 136 girls) were admitted to Vietnam National Children's Hospital from January 2022 to June 2023. The median age was 85 (range: 2-188) months, and only 12 (3.1%) patients had comorbidities. 161 (41.2%) patients required PICU admission, and the median PICU LOS was 4 (2-7) days. We observed independent factors related to PICU admission, including CRP ≥ 50 (mg/L) (OR 2.52, 95% CI 1.39-4.56, p = 0.002), albumin ≤ 30 (g/L) (OR 3.18, 95% CI 1.63-6.02, p = 0.001), absolute lymphocyte count ≤ 2 (× 109/L) (OR 2.18, 95% CI 1.29-3.71, p = 0.004), ferritin ≥ 300 (ng/mL) (OR 2.35, 95% CI 1.38-4.01), p = 0.002), and LVEF < 60 (%) (OR 2.48, 95% CI 1.28-4.78, p = 0.007). Shock developed in 140 (35.8%) patients, especially for those decreased absolute lymphocyte ≤ 2 (× 109/L) (OR 2.48, 95% CI 1.10-5.61, p = 0.029), albumin ≤ 30 (g/L) (OR 2.53, 95% CI 1.22-5.24, p = 0.013), or LVEF < 60 (%) (OR 2.24, 95% CI 1.12-4.51, p = 0.022). In conclusion, our study emphasized that absolute lymphocyte count, serum albumin, CRP, and LVEF were independent predictors for MIS-C severity. Further well-designed investigations are required to validate their efficacy in predicting MIS-C severe cases, especially compared to other parameters. As MIS-C is a new entity and severe courses may progress aggressively, identifying high-risk patients optimizes clinicians' follow-up and management to improve disease outcomes.

Ileocecal Intussusception in the Era of Coronavirus Disease 2019 (COVID-19) Infection and Multisystem Inflammatory Syndrome in Children (MIS-C): A Case Report and Literature Review.

Ileocecal intussusception (ICI) is the most common abdominal emergency and cause of intestinal obstruction in young children, carrying a high risk of mortality and morbidity. Enteric viral infectious and inflammatory syndromes are known triggers for intussusception (ileoileal and ileocolic) by causing mesenteric lymphoid hyperplasia that may act as a leading point allowing the bowel to invaginate into itself. Gastrointestinal (GI) symptoms are common in children with coronavirus disease 2019 (COVID-19) infection, with a subset of patients solely having GI complaints at the time of presentation.  COVID-19 as a trigger for intussusception in children has been hypothesized and suggested in multiple cases reported to date, both during the acute phase of illness and as a part of multisystem inflammatory syndrome in children (MIS-C). We present a seven-month-old male who developed ICI and became a diagnostic dilemma due to viral co-infections and the gradual emergence of MIS-C during the hospital stay. We are describing this presentation in an attempt to expand the understanding of the implications of COVID-19 and MIS-C in this young and unique age group.

MIS-C Treatment: Is glucocorticoid monotherapy enough for mild cases?

BACKGROUND: The effectiveness of using only glucocorticoids (GCs) in mild multisystem inflammatory syndrome (MIS-C) cases was compared with combined treatment [GCs + Intravenous immune globulin (IVIG)]. METHODS: This retrospective cohort study was conducted between June 1, 2020, and June 1, 2022, in a tertiary care center in Istanbul, Turkey. Clinical and investigational data of the MIS-C patients were analyzed. The patients were divided into two groups: those who received only GCs and those who received the GCs + IVIG combination. The primary outcome focused on assessing the deterioration of the patient's clinical condition, the occurrence of shock, admission to the pediatric intensive care unit (PICU), and the need for additional immunosuppressive medication. Secondary outcomes included evaluating the course of cardiovascular and infection-related complications observed at the one-year follow-up. RESULTS: Ninety-seven MIS-C patients with a median age of 41 (3- 214) months were enrolled. Fifty-six (57.7%) patients were male. All the patients had fever at admission with a temperature of 39 °C (37.5 °C-40.1 °C). Thirty-two patients (33%) had cardiac findings on echocardiography [left ventricular dysfunction (n= 13, 13.5%), coronary artery involvement (n= 11, 11.3%), and dilation of cardiac cavities and/or increased cardiac muscle thickness (n= 8, 8.2%)]. Thirteen patients (13.5%) required intensive care. All patients received GCs [only GCs (group I; n= 65, 67%)], and 32 patients (33%) with severe manifestations and/or cardiac involvement received GCs + IVIG (group II). No mortality was observed. None of the patients had any complaints at the one-year follow-up, and all echocardiography findings were normal. CONCLUSION: This study provides preliminary evidence that GC monotherapy is a safe treatment alternative for mild MIS-C cases without cardiac involvement.

Advancing Kawasaki Disease Research in the Arab World: Scoping Literature Review Analysis with Emphasis on Giant Coronary Aneurysms.

To evaluate giant aneurysms (GiAn) prevalence in Arab countries and examine contributing factors; and to review Kawasaki disease (KD) publication trends and collaborations among Arab nations. A scoping literature review was conducted to analyze the publications across the Arab world, spanning 16 countries from 1978 to 2023. The collected articles were a combination of database search with a call on Kawasaki Disease Arab Initiative (Kawarabi) members to share non-PubMed publications. Over 45 years, 50 articles originated from the Arab Countries with a 30% average annual growth rate in KD research output. Publications were evenly split between case reports (42%) and institutional series (52%). Research productivity lagged in developing nations with UAE, KSA and Egypt, contributed to 64% of total publications. Among 26 institutional series, 256 coronary artery aneurysms (CAA) from a total of 1264 KD cases were reported. Of those, 25 CAA were GiAn (prevalence 1.43% [range 0-12.5%]). The initial KD misdiagnosis rate was 4%, and incomplete KD (iKD) averaged 10.6%. Series (38.5%) that did not report iKD correlated with a higher prevalence of CAA, but not of GiAn. Longer fever duration emerged as a pivotal factor for GiAn (OR 5.06, 95%CI 1.51-17). This review unveils the research landscape of KD in the Arab world over 45 years. Initial misdiagnosis, untreated cases, delayed diagnosis and underreporting of iKD are contributing factors for an underestimated epidemiology, explaining the higher GiAn prevalence. This calls for strategic interventions to enhance KD research in these countries, aligning with Kawarabi's mission.

Human Genetic and Immunological Determinants of SARS-CoV-2 Infection and Multisystem Inflammatory Syndrome in Children.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) induces pneumonia and acute respiratory failure in Coronavirus Disease 2019 (COVID-19) patients with inborn errors of immunity to type I interferon (IFN-I). The impact of SARS-CoV-2 infection varies widely, ranging from mild respiratory symptoms to life-threatening illness and organ failure, with a higher incidence in men than in women. Approximately 3 to 5% of critical COVID-19 patients under 60 and a smaller percentage of elderly patients exhibit genetic defects in IFN-I production, including X-chromosome-linked TLR7 and autosomal TLR3 deficiencies. Around 15 to 20% of cases over 70 years old, and a smaller percentage of younger patients, present with preexisting autoantibodies neutralizing type I interferons. Additionally, innate errors affecting the control of the response to type I interferon have been associated with pediatric multisystem inflammatory syndrome (MIS-C). Several studies have described rare errors of immunity, such as XIAP deficiency, CYBB, SOCS1, OAS1/2, and RNASEL, as underlying factors in MIS-C susceptibility. However, further investigations in expanded patient cohorts are needed to validate these findings and pave the way for new genetic approaches to MIS-C. This review aims to present recent evidence from the scientific literature on genetic and immunological abnormalities predisposing individuals to critical SARS-CoV-2 infection through IFN-I. We will also discuss multisystem inflammatory syndrome in children (MIS-C). Understanding the immunological mechanisms and pathogenesis of severe COVID-19 may inform personalized patient care and population protection strategies against future serious viral infections.

Role of Vitamin D and Vitamin D Polymorphisms in COVID-19 Risk and Severity in Children: A Systematic Review.

The role of vitamin D in the susceptibility to coronavirus disease 2019 (COVID-19) disease has been investigated since the beginning of the pandemic, but there is still scarce data on children. We investigated the impact of vitamin D status and the related genetic variants on COVID-19 vulnerability and severity of the disease in children. A systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, to identify reports on vitamin D status and genetic polymorphisms, their association with the susceptibility of children to COVID-19 and multisystem inflammatory syndrome in children (MIS-C), and the effect of supplementation on the clinical course. Of an initial total of 279 articles, 26 studies, published between September 2020 and May 2023, were finally included in this review according to inclusion criteria. Quantitative data provided by 11 studies revealed that 43.05% of pediatric COVID-19 patients had low vitamin D levels. Mean serum 25(OH)D levels were observed to be significantly low in COVID-19 cases, with an estimated pooled mean value of 17 ng/mL, as provided by 16 studies. Vitamin D deficiency and the vitamin D receptor (VDR) FokI polymorphism may suggest independent risk factors for susceptibility to COVID-19 in the pediatric population. The 25(OH)D level may constitute a significant biomarker associated with the COVID-19 severity and MIS-C. While supplementation of COVID-19 cases with vitamin D showed favorable results, the effect on the outcome of the disease remains uncertain.

From multisystem inflammatory syndrome in children to secondary hemophagocytic lymphohistiocytosis a series of misfortunate events: case report and review of literature.

Multisystem inflammatory syndrome of childhood (MIS-C) is a recently described entity in pediatrics post-COVID-19 pandemic. Hemophagocytic lymphohistiocytosis (HLH) is a clinical syndrome caused by an unregulated proliferation of macrophages as well as T lymphocytes. Both entities can be considered overlapping, although distinct criteria for each can be found in the literature. Herein, we report a patient with MIS-C post-COVID-19 infection, complicated with HLH secondary to Plasmodium falciparum malaria from a blood transfusion.

Evolution of the Antigenic Landscape in Children and Young Adults with COVID-19 and MIS-C.

There is minimal knowledge regarding the durability of neutralization capacity and level of binding antibody generated against the highly transmissible circulating Omicron subvariants following SARS-CoV-2 infection in children with acute COVID-19 and those diagnosed with multisystem inflammatory syndrome in children (MIS-C) in the absence of vaccination. In this study, SARS-CoV-2 neutralization titers against the ancestral strain (WA1) and Omicron sublineages were evaluated in unvaccinated children admitted for COVID-19 (n = 32) and MIS-C (n = 32) at the time of hospitalization (baseline) and at six to eight weeks post-discharge (follow-up) between 1 April 2020, and 1 September 2022. In addition, antibody binding to the spike receptor binding domain (RBD) from WA1, BA.1, BA.2.75, and BA.4/BA.5 was determined using surface plasmon resonance (SPR). At baseline, the children with MIS-C demonstrated two-fold to three-fold higher binding and neutralizing antibodies against ancestral WA1 compared to those with COVID-19. Importantly, in children with COVID-19, the virus neutralization titers against the Omicron subvariants at six to eight weeks post-discharge reached the same level as those with MIS-C had at baseline but were higher than titers at 6-8 weeks post-discharge for MIS-C cases. Cross-neutralization capacity against recently emerged Omicron BQ.1, BQ.1.1, and XBB.1 variants was very low in children with either COVID-19 or MIS-C at all time points. These findings about post-infection immunity in children with either COVID-19 or MIS-C suggest the need for vaccinations in children with prior COVID-19 or MIS-C to provide effective protection from emerging and circulating SARS-CoV-2 variants.

The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

Rocky Mountain Spotted Fever Mimicking Multisystem Inflammatory Syndrome in Hospitalized Children, Sonora, Mexico.

We describe 5 children who had Rocky Mountain spotted fever (RMSF) and manifested clinical symptoms similar to multisystem inflammatory syndrome in Sonora, Mexico, where RMSF is hyperendemic. Physicians should consider RMSF in differential diagnoses of hospitalized patients with multisystem inflammatory syndrome to prevent illness and death caused by rickettsial disease.

Describing Elephants: An Update on the Immunopathology of Multisystem Inflammatory Syndrome in Children.

First described in 2020, multi-system inflammatory syndrome in children (MIS-C) is an, initially life-threatening, disease characterised by severe inflammation and following exposure to SARS-CoV-2. The immunopathology of MIS-C involves a hyperinflammation characterised by a cytokine storm and activation of both the innate and adaptive immune system, eventually leading to multi-organ failure. Several etiological theories are described in literature. Firstly, it is suggested that the gut plays an important role in the translocation of microbial products to the systemic circulation. Additionally, the production of autoantibodies that develop after the initial infection with SARS-CoV-2 might lead to many of its broad clinical symptoms. Finally, the superantigen theory where non-specific binding of the SARS-CoV-2 spike glycoprotein to the T-cell receptor leads to a subsequent activation of T cells, generating a powerful immune response. Despite the sudden outbreak of MIS-C and alarming messages, as of 2024, cases have declined drastically and subsequently show a less severe clinical spectrum. However, subacute cases not meeting current diagnostic criteria might be overlooked even though they represent a valuable research population. In the future, research should focus on adjusting these criteria to better understand the broad pathophysiology of MIS-C, aiding early detection, therapy, and prediction.

[Hyperinflammatory immune response syndrome PIMS-TS]. / «Nachwehen¼: Hyperinflammatorisches Immunreaktionssyndrom PIMS-TS.

INTRODUCTION: PIMS-TS is a rare hyperinflammatory immune response syndrome, usually occurring two to six weeks after SARS-CoV-2 infection, which mainly affects schoolchildren and is often associated with the need for intensive care (2). The most common clinical signs are high fever, gastrointestinal symptoms such as abdominal pain, vomiting and diarrhea, cardiovascular dysfunction (impaired LVEF, hypotension, shock) and neurological symptoms such as headache and encephalopathy (1, 2, 4). The definition criteria include various clinical and laboratory parameters, which vary slightly depending on the authors (4, 6, 7). With intensive care treatment with circulatory support and administration of methylprednisolone, mortality and long-term consequences remain low.

Are we overdiagnosing multisystem inflammatory syndrome in children (MIS-C)? A case series of children with bacterial infection mimicking MIS-C.

INTRODUCTION: Multisystem inflammatory syndrome in children (MIS-C) is a serious hyperinflammatory condition associated with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. Usually, the diagnosis of MIS-C is made by criteria defined by international organizations, which include specific clinical features, laboratory findings, and evidence of SARS-CoV-2 infection. We hereby present a case series of three children. The objective of this case series, involving chart review of medical records of children admitted with MIS-C, is to emphasize that the features of MIS-C may overlap with other conditions. CASE PRESENTATION: Three children were presented with MIS-C based on World Health Organization (WHO) criteria and given treatment for the same. However, due to persistent symptoms, they were further worked up and diagnosed to have underlying bacterial infections which included liver abscess, enteric fever, or urinary tract infection. CONCLUSIONS: The criteria for MIS-C may overlap with other conditions, particularly bacterial infection that may lead to overdiagnosis of MIS-C. Therefore, one should be very careful in making an MIS-C diagnosis and other differential diagnoses should be considered when the symptoms persist or worsen.

Cardiovascular involvement in children with COVID-19 temporally related multisystem inflammatory syndrome (MIS-C): can cardiac magnetic resonance arrive to the heart of the problem?

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) shows a significant overlap of symptoms with other hyper-inflammatory diseases such as Kawasaki disease (KD), but the real difference of the two conditions is still matter of debate. Coronary artery lesions (CAL) are the most relevant complication in KD. Nonetheless, CAL, myocarditis, pericarditis, arrhythmia are the main cardiovascular complications in MIS-C. A close clinical assessment is mandatory, both at the diagnosis and during the follow-up, by ECG and echocardiography. Cardiac magnetic resonance (MRI) adds important data to ultrasound findings. However, cardiac MRI studies in MIS-C are limited to a small number of cohorts. METHODS: We enrolled 20 children (age:1-16 years; 11 F; 9 M) with cardiac involvement secondary to MIS-C, all evaluated by cardiac MRI. RESULTS: 8 children showed pathological cardiac MRI: 2 showed pericardial effusion; 2 showed myocardial oedema; 1 showed aortic insufficiency; 3 showed delayed enhancement (one for acute myocarditis with oedema; 2 for myocardial fibrosis). Delayed enhancement was reduced significantly 5.6-9 months after the first MRI evaluation. 25% of patients with pathological MRI had CAL associated with valvular insufficiency of 2 valves. 17% of patients with normal MRI had CAL, associated with valvular insufficiency of 1 valve in 1 patient. The correlations between haematological, clinical, cardiologic parameters, treatment, did not reach the statistical significance. 4 patients were treated with anakinra. Among those, 2 patients showed a normal cardiac MRI. Cardiac lesions resolved in all the patients during the follow-up. Some patients with pathological cardiac MRI could not underwent a control with MRI, for the low compliance. However, echocardiography and ECG, documented the resolution of the pathological data in these cases. CONCLUSIONS: A higher risk of CAL was documented in patients with an association of other cardiac lesions. Cardiac MRI is difficult to perform routinely; however, it is useful for evaluating the acute myocardial damage and the outcome of patients with MIS-C.

Diagnostic testing for chest pain in a pediatric emergency department and rates of cardiac disease before and during the COVID-19 pandemic: a retrospective study.

Objectives: Chest pain is a common chief complaint in pediatric emergency departments (EDs). Coronavirus disease-2019 (COVID-19) has been shown to increase the risk of cardiac disease. It remains unclear how COVID-19 changed how pediatric emergency clinicians approach patients presenting with chest pain. The goal of this study was to characterize the diagnostic testing for chest pain in a pediatric ED before and during the COVID-19 pandemic. Methods: This was a retrospective study of children between the ages of 2-17 years presenting to a pediatric ED from 1/1/2018-2/29/2020 (Pre-COVID-19) and 3/1/2020-4/30/2022 (COVID-19) with chest pain. We excluded patients with a previous history of cardiac disease. Results: Of the 10,721 encounters during the study period, 5,692 occurred before and 5,029 during COVID-19. Patient demographics showed minor differences by age, weight, race and ethnicity. ED encounters for chest pain consisted of an average of 18% more imaging studies during COVID-19, including 14% more EKGs and 11% more chest x-rays, with no difference in the number of echocardiograms. Compared to Pre-COVID-19, 100% more diagnostic tests were ordered during COVID-19, including cardiac markers Troponin I (p < 0.001) and BNP (p < 0.001). During COVID-19, 1.1% of patients had a cardiac etiology of chest pain compared with 0.7% before COVID-19 (p = 0.03). Conclusions: During COVID-19, pediatric patients with chest pain underwent more diagnostic testing compared to Pre-COVID-19. This may be due to higher patient acuity, emergence of multisystem inflammatory syndrome in children (MIS-C) that necessitated more extensive testing and possible changes in ED clinician behavior during COVID-19.

Proteomic mapping identifies serum marker signatures associated with MIS-C specific hyperinflammation and cardiovascular manifestation.

Multisystem inflammatory syndrome in children (MIS-C) shares several clinical and immunological features with Kawasaki Disease (KD) and pediatric hyperinflammation, but the immuno-phenotypic overlap among these clinical mimics is still incompletely understood. Here we analyzed serum samples from treatment-naïve patients with MIS-C (n = 31) and KD (n = 11), pediatric hyperinflammation (n = 13) and healthy controls (HC, n = 10) by proximity extension assay (PEA) to profile 184 blood biomarkers. Collectively, immunophenotypic overlap between MIS-C and hyperinflammation exceeds overlap with KD. Overexpression of IL-17A in MIS-C and KD could best separate these conditions from hyperinflammatory conditions, while those were hallmarked by overabundance of adenosin deaminase and IL-18. Depletion in serum TNF-related subfamily member 9 (TNFRSF9) and apoptosis inducing ligand (TRAIL) linked with cardiovascular manifestations and myocarditis in MIS-C. Altogether, our analysis highlights important differences in molecular marker signatures also across different MIS-C and KD cohorts and suggests several previously unidentified molecular associations in context of cardiovascular inflammation.

Serum proteomics reveals hemophagocytic lymphohistiocytosis-like phenotype in a subset of patients with multisystem inflammatory syndrome in children.

Children with Multisystem Inflammatory Syndrome in Children (MIS-C) can present with thrombocytopenia, which is a key feature of hemophagocytic lymphohistiocytosis (HLH). We hypothesized that thrombocytopenic MIS-C patients have more features of HLH. Clinical characteristics and routine laboratory parameters were collected from 228 MIS-C patients, of whom 85 (37%) were thrombocytopenic. Thrombocytopenic patients had increased ferritin levels; reduced leukocyte subsets; and elevated levels of ASAT and ALAT. Soluble IL-2RA was higher in thrombocytopenic children than in non-thrombocytopenic children. T-cell activation, TNF-alpha and IFN-gamma signaling markers were inversely correlated with thrombocyte levels, consistent with a more pronounced cytokine storm syndrome. Thrombocytopenia was not associated with severity of MIS-C and no pathogenic variants were identified in HLH-related genes. This suggests that thrombocytopenia in MIS-C is not a feature of a more severe disease phenotype, but the consequence of a distinct hyperinflammatory immunopathological process in a subset of children.

Fatal Arrhythmic Complications of Multisystemic Inflammatory Syndrome (MIS-C) in a Pediatric Patient.

In 2019, the emergence of the coronavirus disease 2019 (COVID-19) virus triggered a global pandemic, reminiscent of the magnitude witnessed during the flu pandemic of 1918. Initially, children often presented with either asymptomatic or mild upper respiratory tract infection symptoms. However, in the post-acute phase, a distinct syndrome affecting multiple organ systems emerged, sharing similarities with Kawasaki's disease. This syndrome was later classified as multisystem inflammatory syndrome in children (MIS-C) by the Pediatric Intensive Care Society in April 2020. Notably, cardiac manifestations and complications associated with COVID-19 constitute a significant source of morbidity and mortality, characterized by left ventricular dysfunction, cardiac conduction abnormalities, and arrhythmias. Although cases of arrhythmias with MIS-C are rare in the literature, we present a unique case involving a 14-year-old without known cardiac risk factors who presented with conduction abnormalities and fatal arrhythmias secondary to MIS-C.

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.