Cardiac involvement is a key prognostic factor in multisystem inflammatory syndrome in children (MIS-C), a rare but serious inflammatory condition that typically occurs 2-6 weeks after SARS-CoV-2 infection and is characterized by fever, systemic inflammation, and multiorgan involvement. Biomarkers may aid in early detection, severity assessment, and treatment stratification.

To evaluate the diagnostic utility of established and emerging serum biomarkers in MIS-C, with an emphasis on cardiac dysfunction and disease severity.

A systematic search was conducted in PubMed, Scopus, and Web of Science up to April 2025. Eligible studies included pediatric MIS-C cases with reported serum biomarkers. Meta-analyses were performed for NT-proBNP and troponin using random-effects models. Descriptive profiling was applied to emerging biomarkers. Subgroup comparisons were explored between severe and moderate MIS-C. Quality assessment followed the Newcastle-Ottawa Scale, and publication bias was assessed via funnel plots and Egger's test.

A total of 67 studies were included, comprising >4000 pediatric MIS-C cases. NT-proBNP and troponin were consistently elevated (pooled means: 9697 pg/mL and 0.384 ng/mL, respectively), with a low risk of publication bias. Emerging biomarkers such as CXCL9, angiopoietin-2, and vitamin D revealed high inter-study variability but potential prognostic value. Subgroup analyses for selected studies (n = 5) suggested higher biomarker levels in severe MIS-C.

NT-proBNP and troponin are robust indicators of cardiac injury in MIS-C. Emerging biomarkers show promise but require validation. Future studies should include copeptin and adopt standardized reporting to refine biomarker-guided management.

Multisystem inflammatory syndrome in children (MIS-C) is a potentially life-threatening condition associated with cardiac involvement. Cardiac point-of-care ultrasound (POCUS) can be performed at the bedside in the pediatric emergency department (PED) to identify cardiac pathology. There is limited data on cardiac POCUS findings in children with MIS-C in the PED. The main outcome objective of our study was to describe the cardiac POCUS findings in MIS-C patients in the PED.

This is a multicenter, retrospective, cohort study between February 15, 2021 and March 31, 2022, during the alpha, delta, and omicron severe acute respiratory syndrome coronavirus 2 waves in 6 PEDs in Israel. We included patients diagnosed with MIS-C who received a cardiac POCUS examination in the PED. All POCUS clips were analyzed by a PED POCUS expert.

We included 32 MIS-C patients who underwent cardiac POCUS during the study period. The median age was 8 years (interquartile range = 6 to 10 y), and 20 (63%) were males. The median time from onset of symptoms upon PED visit was 5 days (interquartile range = 4 to 5 d). Overall, 27 patients (84%) were diagnosed with normal cardiac function and 5 patients with decreased cardiac function (16%). No patients were diagnosed with pathologic cardiac effusion. Three patients were diagnosed with plethoric inferior vena cava. Among the patients, 17 (53%) were admitted to the pediatric wards and 15 (47%) to the pediatric intensive care unit. There was no mortality.

Cardiac POCUS by PEM physicians is an applicable tool for the evaluation of MIS-C patients in the PED. In our study, 16% of MIS-C patients who underwent POCUS had decreased cardiac function per POCUS on their PED presentation. Future studies are needed to evaluate the impact of cardiac POCUS in the PED of patients with MIS-C.

Pediatric Inflammatory Multisystem Syndrome (PIMS-TS), associated with SARS-CoV-2 infection, is a severe complication after COVID-19 in children. It is caused by the immune reaction to SARS-CoV-2, and usually appears three to six weeks after the infection. Unfortunately, PIMS causes non-specific symptoms, which makes its diagnosis and treatment difficult. In this paper, we propose Fourier Transform InfraRed spectrometry (FTIR) to identify chemical changes in blood serum of children induced by PIMS and caused by subsequent treatment of the syndrome. The results suggest that although the Principal Component Analysis (PCA) of FTIR data did not allow for differentiation of healthy children and children with PIMS before and after the treatment, the implementation of Support Vector Machine (SVM) showed that the accuracy of the FTIR region between 800 cm- 1 and 1800 cm- 1 in PIMS detection is as high as 92% with a sensitivity of 100%. The difference in the chemical compositions of sera from the control group and the children after the treatment was detected in 54%, indicating that the treatment was effective. Indeed, the obtained medical data clearly showed a decrease of C-reactive protein (CRP) and Procalcitonin (PCT) concentration in serum after the treatment. The decision tree showed that peak 1455 cm- 1 could be used as a potential FTIR PIMS marker. Importantly, FTIR data correlates well with medical parameters, however the correlation differs with respect to the groups before and after the treatment.

The etiology of multisystem inflammatory syndrome in children (MIS-C), frequently observed following COVID-19 infection, remains elusive. This study unveils insights derived from cytokine analysis in the sera of MIS-C patients, both before and after the administration of intravenous immunoglobulin (IVIG) and glucocorticosteroids (GCS). In this study, we employed a comprehensive 45-cytokine profile encompassing a spectrum of widely recognized proinflammatory and antiinflammatory cytokines, as well as growth factors, along with other soluble mediators. The analysis delineates three principal cytokine-concentration patterns evident in the patients' sera. Pattern no.1 predominantly features proinflammatory cytokines (IL-6, IL-15, IL-1ra, granulocyte-macrophage colony-stimulating factor (GM-CSF), tumor necrosis factor α (TNFα), C-X-C motif chemokine ligand 10 (CXCL10/ IP-10), and IL-10) exhibiting elevated concentrations upon admission, swiftly normalizing post-hospital treatment. Pattern no. 2 includes cytokines (IL-17 A, IL-33, IFNγ, vascular endothelial growth factor (VEGF), and programmed death ligand (PD-L1)) with moderately elevated levels at admission, persisting over 7-10 days of hospitalization despite the treatment. Pattern no. 3 comprises cytokines which concentrations escalated after 7-10 days of hospitalization and therapy, including IL-1α, IL-1β, IL-2, IL-13, platelet-derived growth factor AA/BB (PDGF AA/BB). The observed in cytokine profile of MIS-C patients showed a transition from acute inflammation to sustaining inflammation which turned into induction of humoral memory mechanisms and various defense mechanisms, contributing to recovery.

Our aim was to investigate all children admitted to paediatric intensive care units (ICU) in the Republic of Ireland between January 2020 and August 2022 with an admitting diagnosis of acute COVID-19 infection or paediatric inflammatory multi-system syndrome, temporally associated with SARS-CoV-2 (PIMS-TS) or associated illness. The patients were identified to catalogue the severity of illness, analyse cardiovascular manifestations of their disease, and short-term outcomes.

This is a retrospective multi-centre observational study.

127 children were admitted to paediatric ICU in Ireland with a COVID-19- related illness between January 2020 and August 2022. 87 (68.5%) of patients had acute COVID-19 infection, 39 (30.7%) had PIMS-TS and 1 (0.8%) patient had post-COVID vaccine-related myocarditis. Ventilatory support was required for 47/87 (54%) in the COVID-19 group comparative to 9/39 (23%) of patients with PIMS-TS. Inotropic support was required for 13/87 (14.9%) children with COVID-19 and 29/39 (74.3%) with PIMS-TS. Evidence of any cardiac disease on ECHO was identified in 23/38 (60.5%) of the PIMS-TS cohort comparative to only 5/36 (13.9%) of patients with COVID-19. 38/39 (97.4%) of patients with PIMS-TS-related cardiac disease and 100% with COVID-19 had a normal echo at the time of discharge from hospital. Overall survival of patients was 100%.

The burden of cardiac disease in children requiring paediatric ICU care for COVID-19-related disease was high in the acute phase; however, all children survived, and all cardiac investigations had normalised by short-term follow-up.

Multisystem inflammatory syndrome associated to Covid-19 (MIS-C) is one of the most severe outcomes of SARS-CoV-2 in children. Covid-19 vaccines were successfully implemented in Chile for the pediatric population since 2021, using both mRNA and inactivated platforms. Effectiveness against MIS-C has been reported for mRNA vaccines. The aim of this study was to describe the epidemiologic trend of MIS-C in Chile during Covid-19 pandemic, both before and after the availability of vaccination for children.

Analytic study of MIS-C cases from April 2020 to December 2022. Epidemiological data, SARS-CoV-2 variants and vaccination uptake information were obtained from the Epidemiology Department-Ministry of Health, Institute of Public Health and the National Immunization Program, respectively.

496 cases of MIS-C were reported, 58 % males. Median age was 5 years and most frequent age-cohorts were 6-11 and 0-2 years old with a 33 % each. After the introduction of the Covid-19 vaccine, most cases occurred in children aged 0-2 years. Incidence rates were 3.8, 5.4 and 1.7 per 100,000 inhabitants in 2020, 2021 and 2022, respectively. 97 % of cases (481) occurred in unvaccinated subjects. On those previously vaccinated (15), all but one case occurred in children receiving the inactivated vaccine. No association among circulating variants and incidence was observed. Incidence rate reduction (IRR) comparison between 2020 and 2021-2022 periods was 0.72 (CI 95 % 0.65-0.81, p < 0.05) overall; 0.86 for 0-2 years (CI 95 %:0.71-1; p = 0.12); 0.88 for 3-5 years (CI 95 %:0.69-1.11; p = 0.28); 0.61 for 6-11 years (CI 95 %: 0.50-0.75; p < 0.05); and 0.64 for 12-17 years (CI 95 %:0.47-0.89; p < 0.05), consistent with vaccination uptake during the studied period: 63 % for 3-5 years, 91 % for 6-11 years, and 99 % for 12-17 years.

A decline of MIS-C incidence and a shift to younger, unvaccinated population overtime was observed. IRR decreased in age-cohorts which achieved high vaccination rates.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a secondary immune manifestation of COVID-19 involving multiple organ systems in the body, resulting in fever, skin rash, abdominal pain, nausea, shock, and cardiac dysfunction that often lead to hospitalization. Although many of these symptoms resolve following anti-inflammatory treatment, the long-term neurological and psychiatric sequelae of MIS-C are unknown. In this review, we will summarize two domains of the MIS-C disease course, 1) Neuroinflammation in the MIS-C brain and 2) Psychosocial disruptions resulting from stress and hospitalization. In both domains, we present existing clinical findings and hypothesize potential connections to psychiatric outcomes. This is the first review to conceptualize a holistic framework of psychiatric risk in MIS-C patients that includes neuroinflammatory and psychosocial risk factors. As cases of severe COVID-19 and MIS-C subside, it is important for clinicians to monitor outcomes in this vulnerable patient population.

Knowledge about multisystem inflammatory syndrome in children (MIS-C) is evolving, and evidence-based standardised diagnostic and management protocols are lacking. Our review aims to summarise the clinical and diagnostic features, management strategies and outcomes of MIS-C and evaluate the variances in disease parameters and outcomes between high-income countries (HIC) and middle-income countries (MIC).

We searched four databases from December 2019 to March 2023. Observational studies with a sample size of 10 or more patients were included. Mean and prevalence ratios for various variables were pooled by random effects model using R. A mixed generalised linear model was employed to account for the heterogeneity, and publication bias was assessed via funnel and Doi plots. The primary outcome was pooled mean mortality among patients with MIS-C. Subgroup analysis was conducted based on the income status of the country of study.

A total of 120 studies (20 881 cases) were included in the review. The most common clinical presentations were fever (99%; 95% CI 99.6% to 100%), gastrointestinal symptoms (76.7%; 95% CI 73.1% to 79.9%) and dermatological symptoms (63.3%; 95% CI 58.7% to 67.7%). Laboratory investigations suggested raised inflammatory, coagulation and cardiac markers. The most common management strategies were intravenous immunoglobulins (87.5%; 95% CI 82.9% to 91%) and steroids (74.7%; 95% CI 68.7% to 79.9%). Around 53.1% (95% CI 47.3% to 58.9%) required paediatric intensive care unit admissions, and overall mortality was 3.9% (95% CI 2.7% to 5.6%). Patients in MIC were younger, had a higher frequency of respiratory distress and evidence of cardiac dysfunction, with a longer hospital and intensive care unit stay and had a higher mortality rate than patients in HIC.

MIS-C is a severe multisystem disease with better mortality outcomes in HIC as compared with MIC. The findings emphasise the need for standardised protocols and further research to optimise patient care and address disparities between HIC and MIC.

CRD42020195823.

Coronavirus is an important pathogen causing disease in humans and animals. At the end of 2019, an investigation into an increase in pneumonia cases in Wuhan, Hubei Province, China, found that the cause was a new coronavirus. This disease, which spread rapidly across China and caused an outbreak worldwide, resulted in a pandemic. Although this virus has previously been referred to as 2019-nCoV, which causes coronavirus disease 2019 (COVID-19), later it was named severe acute respiratory syndrome coronavirus 2. Children were usually asymptomatic and rarely severely affected. In April 2020, reports from the United Kingdom indicated that children may have Kawasaki disease or a clinical condition similar to toxic shock syndrome. This clinical picture was later defined as multisystem inflammatory syndrome in children. Since then, similarly affected children as well as cases with other cardiac complications have been reported in other parts of the world. In this review, we aimed to evaluate COVID-19 in terms of cardiac involvement by reviewing the literature.

The clinical features of Multisystem Inflammatory Syndrome in Children (MIS-C) have been well documented, but there is limited data regarding the short term and longitudinal outcomes of children living in rural areas. We report the demographic and clinical features, as well as the multi-specialty follow-up of patients with MIS-C served by a large tertiary care rural health system.

Patients that met the Centers for Disease Control (CDC) case definition of MIS-C admitted between March 1, 2020, and March 31, 2021, were included in this case series. Manual chart review was used to report demographic characteristics, clinical, laboratory and radiologic features during acute hospitalization and multispecialty follow-up, and adherence to follow-up 6-10 weeks after hospital discharge.

Twenty-one patients with MIS-C were admitted at our center during the review period. Ninety percent of the cohort required intensive care during hospitalization. Of 19 patients with measured ejection fractions, 52 % had some degree of left ventricular dysfunction on admission; nine patients had electrocardiogram changes on admission. The majority of patients had elevated inflammatory markers during hospitalization. Most patients had resolution of symptoms, improvement in inflammatory markers, and normal cardiac function at the time of discharge. Follow-up with pediatric cardiology, hematology-oncology and infectious disease was indicated for most patients at discharge. Of these, 100 % of patients kept initial follow-up appointments with pediatric cardiology and infectious disease, while 94 % kept initial follow-up appointments with pediatric hematology-oncology.

Though most patients were critically ill during hospitalization, the majority had resolution of cardiac abnormalities and inflammatory markers at discharge and timely follow-up with multiple subspecialists after admission with MIS-C.

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

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

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.

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.

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 global COVID-19 pandemic forced changes in everyday life of children and adolescents due to government containment measures, an altered healthcare accessibility and utilization, and public concern about SARS-CoV-2 transmission. Data on the challenges and impact on children and their families with chronic diseases are limited. The primary objectives of this study were to assess (i) concerns for SARS-CoV-2 infection, (ii) perceived effects on health-related and overall quality of life (HRQoL and QoL), and (iii) accessibility and utilization of healthcare, comparing families with chronically ill children to families with healthy children during the second SARS-CoV-2 infection wave in Germany. A caregiver questionnaire was designed and participation offered in the emergency department and outpatient clinic of a German tertiary care children's hospital. 45.9% of the 205 participants were majorly concerned about their children contracting a SARS-CoV-2 infection. Caregivers of chronically ill children (128/205, 62.4%) stated significantly more often a negative impact on their child's QoL (w = 0.17; p = 0.014), while caregivers of chronically ill adolescents over the age of 13 expressed significantly more frequent a negative impact on their child's HRQoL (w = 0.21; p = 0.016). Outpatient appointments for chronically ill children were significantly more often canceled (w = 0.17; p = 0.025). Caregivers of chronically ill children were significantly more likely to report that they would actively delay hospital visits for emerging health issues due to the pandemic (w = 0.12; p = 0.049).     Conclusion: Our findings underscore the importance of identifying families with chronically ill children as a vulnerable patient group with higher burdens during the COVID-19 pandemic and potential future pandemics. Healthcare providers may mitigate such burdens by ensuring reliable appointment allocation, offering contactless healthcare options, and providing tailored advice regarding vulnerabilities and preventive measures specific to their chronically ill children. What is Known: • The SARS-CoV-2 pandemic has led to significant restrictions in everyday life and both accessibility and utilization of healthcare for children and adolescents. • Chronically ill children faced exceptional challenges as they depend on regular and functioning medical care, but data comparing the pandemic's impact between chronically ill and healthy children are lacking. What is New: • The perceived impact of the SARS-CoV-2 pandemic on quality of life is more negative for chronically ill children and their health-related quality of life is more often affected compared to healthy children. • Caregivers of chronically ill children would more often delay a visit to their child's doctor during the SARS-CoV-2 pandemic and their medical appointments are more often postponed which both could increase health burdens for such vulnerable patients.

Transthoracic echocardiography is an essential and widely available diagnostic tool for assessing individuals reporting cardiovascular symptoms, monitoring those with established cardiac conditions and for preparticipation screening of athletes. While its use is well-defined in hospital and clinic settings, echocardiography is increasingly being utilised in the community, including in the rapidly expanding sub-speciality of sports cardiology. There is, however, a knowledge and practical gap in the challenging area of the assessment of coronary artery anomalies, which is an important cause of sudden cardiac death, often in asymptomatic athletic individuals. To address this, we present a step-by-step guide to facilitate the recognition and assessment of anomalous coronary arteries using transthoracic echocardiography at the bedside; whilst recognising the importance of performing dedicated cross-sectional imaging, specifically coronary computed tomography (CTCA) where clinically indicated on a case-by-case basis. This guide is intended to be useful for echocardiographers and physicians in their routine clinical practice whilst recognising that echocardiography remains a highly skill-dependent technique that relies on expertise at the bedside.

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.

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).

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.

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.

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 (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.

Objectives In the setting of the recent global pandemic, children infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus causing the coronavirus disease 2019 (COVID-19) presented to our hospital with a variety of symptoms ranging from mild to severe disease including multiorgan dysfunction. Our objective was to study the clinical profile, risk factors, complications, and outcomes in pediatric patients admitted to our center with SARS-CoV-2 infection. Methods This retrospective observational study was conducted at a large quaternary center in Riyadh between May 2020 and September 2021. The study population was comprised of children between 0 and ≤14 years with SARS-CoV-2 suspicion or positivity. Results One hundred and fifty-six children were included in the study, the majority of whom were 1-10 years old. One hundred and twenty of them (76.93%) were SARS-CoV-2 positive. Fifty-nine patients (37.18%) were labelled as multisystem inflammatory syndrome in children (MIS-C) based on clinical and lab criteria, of whom 35 (22.44%) tested SARS-CoV-2 positive. Hematological disease was found to be the most common comorbidity, followed by neurological and chronic lung diseases. The most common symptoms encountered were fever, cough, vomiting, fatigue, and diarrhea. Eighty patients (51%) required pediatric intensive care unit (PICU) admission (length of stay: 5-12 days), among whom 32 (40%) required ventilation, 26 (32.5%) needed hemodynamic support, and three patients (3.75%) underwent continuous renal replacement therapy (CRRT). The overall mortality rate was 4.5% (seven patients) among the studied population. The most frequent lab abnormalities were found to be elevated serum ferritin, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and lactate dehydrogenase (LDH) levels. Ninety-one percent received antibiotics, and prophylactic anticoagulant was used in 32%. In the MIS-C subset, 80.5% received steroids, 71.43% intravenous immunoglobulin (IVIG), and 5.17% (three patients) tocilizumab. Conclusion The SARS-CoV-2 infection presented with a range of severity among our cohort of children; however, most of the patients responded well to appropriate supportive treatment. A slight male preponderance was noted. The most common symptoms encountered were fever, cough, vomiting, fatigue, and diarrhea. Inflammatory markers such as ESR, CRP, serum ferritin, and LDH levels were found to be elevated in nearly all patients. Raised serum lactate and serum creatinine and lymphopenia were of significant note in patients with MIS-C. Higher mortality rates were observed in patients with MIS-C and those requiring respiratory support. In addition to these two factors, the presence of comorbidities and the need for CRRT were associated with prolonged PICU length of stay.

Several studies have reported a higher frequency and greater morbidity and mortality of multisystem inflammatory syndrome in children (MIS-C) of black African descent.

We aimed to describe the clinical, laboratory and echocardiographic characteristics as well as outcomes of children with MIS-C requiring admission to a pediatric intensive care unit (PICU) in the French West Indies (FWI), where the majority of the population is Afro-Caribbean.

Ambidirectional observational cohort study between April 1, 2020 and August 31, 2022. Children (age ≤18 years) with MIS-C and organ failure were included. Every patient was monitored and treated following the same protocol, with repeated biological tests, echocardiography, intravenous steroids and polyvalent immunoglobulins. The primary outcomes were clinical, laboratory and echocardiography characteristics.

Forty children (median age 7 years, range: 5-11) were included. The majority (77 %) were included prospectively. Thirty-five (87 %) had gastrointestinal symptoms, 30 (75 %) presented initial heart failure (with persisting diastolic dysfunction at day 7) and 18 (45 %) had pericarditis. Sixteen (40 %) were in cardiogenic shock and required inotropic support. Median duration of inotropic support and hospitalization in PICU were respectively 4 and 5 days. The evolution curves of the inflammatory variables matched after treatment. The clinical outcomes were favorable. The Delta variant was associated with the highest incidence of MIS-C.

This is the first description of MIS-C course among children of Afro-Caribbean descent. The outcomes were good, without any death or cardiac sequelae. Our work does not support an ethnic susceptibility for severity of MIS-C in Afro-Caribbean population.

Between November 2020 and June 2021, twelve children were treated at a university hospital in western France for pediatric multisystem inflammatory syndrome (PIMS). While the clinical presentation may have been reminiscent of Kawasaki disease, PIMS, a new nosological entity, was mentioned in the media in the context of the Covid-19 pandemic. In 2023, research into this syndrome will continue in France and Europe.

This systematic review and meta-analysis were conducted to evaluate the prevalence of cardiac manifestations associated with multisystem inflammatory syndrome in children worldwide. We conducted electronic searches in Ovid MEDLINE, Ovid EMBASE, and the World Health Organization COVID-19 Literature Database from the inception of the SARS-CoV-2 pandemic to 1 January, 2022. Three authors independently screened the abstracts to determine eligibility, assessed methodology in the full texts, and extracted the data.We identified 2848 citations; 94 studies (14,932 patients) were included. The prevalence of vasopressors was 48.2% (95% CI 45.1%, 51.3%), left ventricular systolic dysfunction occurred in 37.2% (95% CI 34.1%, 40.3%), myocarditis in 34.1% (95% CI 30.5%, 37.8%), electrocardiographic dysrhythmias and abnormalities detected in 23.1% (95% CI 18.8%, 27.6%), coronary abnormalities identified in 18% (95% CI 16%, 20%), extracorporeal membrane oxygenation deployed in 2.2% (95% CI 1.7%, 2.8%), and mortality rate of 2.2% (95% CI 1.7%, 2.7%). A sensitivity analysis was performed after removing eleven studies with high bias, and the adjusted prevalence was not different than the original evaluation.In this meta-analysis of the largest cohort of multisystem inflammatory syndrome in children patients to date, we established the most accurate prevalence of the most common cardiac manifestations. Providers will subsequently have more precise data to anticipate patient outcomes and approach discussions concerning the frequency of monitoring outside the acute hospital period.

Paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) may occur 4 to 8 weeks after SARS-CoV-2 infection. The acute presentation of PIMS-TS has been well described, but data on longer-term outcomes, particularly cardiac, is scarce.

This prospective nationwide surveillance study included children and adolescents less than 18 years of age who were hospitalised with PIMS-TS in Switzerland between March 2020 and March 2022. Data was collected from all 29 paediatric hospitals through the Swiss Paediatric Surveillance Unit (SPSU) during hospitalisation and approximately six weeks after discharge. The data was analysed after categorising the participants into three groups based on their admission status to the intensive care unit (ICU) (non-ICU, ICU-moderate) and the requirement for invasive ventilatory and/or inotropic support (ICU-severe).

Overall, 204 children were included of whom 194 (95.1%) had follow-up data recorded. Median age was 9.0 years (interquartile range [IQR] 6.0-11.5) and 142 (69.6%) were male. In total, 105/204 (51.5%) required ICU admission, of whom 55/105 (52.4%) received inotropic support and 14/105 (13.3%) mechanical ventilation (ICU-severe group). Echocardiography was performed in 201/204 (98.5%) children; 132 (64.7%) had a cardiac abnormality including left ventricular systolic dysfunction (73 [36.3%]), a coronary artery abnormality (45 [22.4%]), pericardial effusion (50 [24.9%]) and mitral valve regurgitation (60 [29.9%]). Left ventricular systolic dysfunction was present at admission in 62/201 (30.8%) children and appeared during hospitalisation in 11 (5.5%) children. A coronary artery abnormality was detected at admission in 29/201 (14.2%) children and developed during hospitalisation or at follow-up in 13 (6.5%) and 3 (1.5%) children, respectively. None of the children had left ventricular systolic dysfunction at follow-up, but a coronary abnormality and pericardial effusion were found in 12 (6.6%) and 3 (1.7%) children, respectively. School absenteeism at the time of follow-up was more frequent in children who had been admitted to the ICU (2.5% in the non-ICU group compared to 10.4% and 17.6% in the ICU-moderate and ICU-severe group, respectively) (p = 0.011).

Cardiac complications in children presenting with PIMS-TS are common and may worsen during the hospitalisation. Irrespective of initial severity, resolution of left ventricular systolic dysfunction is observed, often occurring rapidly during the hospitalisation. Most of the coronary artery abnormalities regress; however, some are still present at follow-up, emphasising the need for prolonged cardiac evaluation after PIMS-TS.

The purpose of this study is to describe the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) disease characteristics and management in children admitted to the pediatric intensive care units (PICU).

The present study was based on a national multicentric prospective registry including PICU patients with SARS-CoV2 infection or symptoms of multisystem inflammatory syndrome in children (MIS-C).

A total of 298 patients were admitted to 41 different Spanish PICUs. A total of 76% of them were previously healthy. The most frequent manifestation was MIS-C (69.8%). On admission, 59.4% of patients did not have respiratory distress, and only 17.4% needed conventional mechanical ventilation (MV). The need for MV was associated with age (incidence rate ratios [IRR] 1.21, p < .012), pediatric sequential organ failure assessment score (p-SOFA) Score (IRR 1.12, p = .001), and need for transfusion (IRR 4.5, p < .004) in MIS-C patients, and with vasoactive drug use (IRR 2.73, p = .022) and the diagnosis of acute respiratory distress syndrome (IRR 2.83, p = .018) in patients admitted for other reasons. During the first day of admission, 56% of patients met shock criteria and 50.7% needed vasoactive drugs. In MIS-C patients, their use was associated with higher p-SOFA score (IRR 1.06, p < .001) and with the diagnosis of shock (IRR 5.78, p < .001). In patients without MIS-C, it was associated with higher p-SOFA score (IRR 1.05, p = .022). The mortality rate was 3%, being lower in MIS-C patients compared to patients admitted for other reasons (0.5% vs. 9.4%, p < .001). It was also lower in previously healthy patients compared to patients with previous comorbidities (0.9% vs. 9.7%, p < .001).

Severe SARS-CoV2 infection is uncommon in the pediatric population. In our series, respiratory distress was rare, being MIS-C the most frequent cause of PICU admission related to SARS-CoV2. In most cases, the course of the disease was mild except in children with previous diseases.

To assess the potential long-term cardiac effects after multisystem inflammatory syndrome in children (MIS-C) with cardiovascular involvement in the acute phase.

Our prospective study involved children consecutively diagnosed with MIS-C between October 2020 and February 2022 and followed 6 weeks and 6 months after the disease. In patients with severe cardiac involvement during the acute phase, an additional check-up after 3 months was scheduled. In all patients at all check-ups, 3-dimensional echocardiography and global longitudinal strain (GLS) were used to assess ventricular function.

The study enrolled 172 children aged 1-17 years (median, 8 years). The means of ejection fraction (EF) and GLS for both ventricles were within normal limits after 6 weeks with no relationship with initial severity: left ventricular EF (LVEF) 60% (59%-63%), LV GLS -21.08% (-18.63% to -23.2%), right ventricular (RV) EF 64% (62%-67%), and RV GLS -22.8% (-20.5% to -24.5%). Further, statistically significant improvement of LV function was observed after 6 months-LVEF 63% (62%-65%) and LV GLS -22.55% (-21.05% to -24.25%; P < .05); however, RV function remained unchanged. The group with severe cardiac involvement showed LV function recovery pattern with no significant improvement between 6 weeks and 3 months after MIS-C, while still improving between 3 and 6 months after discharge.

LV and RV function is within normal limits 6 weeks after MIS-C regardless of severity of cardiovascular involvement; LV function improves further between 6 weeks and 6 months after the disease. The long-term prognosis is optimistic with full recovery of cardiac function.

Background: Pediatric inflammatory multisystem syndrome temporarily associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PIMS-TS) is an acute complication of previous SARS-CoV-2 exposure. The relationship between inflammatory markers and anti-inflammatory medication in PIMS-TS is unknown. We retrospectively investigated the relationship between demographics, biomarkers, treatment, and length of stay (LOS) in this novel disease. Methods: We reviewed the case notes and blood tests of all patients who met the Royal College of Paediatrics and Child Health diagnostic criteria for PIMS-TS at a large tertiary center in the United Kingdom. Biomarker trajectories were modeled using log linear mixed effects, and factors affecting LOS in hospital were evaluated using multiple regression. Results: Between March 2020 and May 2022, a total of 56 patients attended Sheffield Children's Hospital with PIMS-TS, 70% male. Mean age was 7.4 ± 3.7 years and mean LOS 8.7 ± 4.5 days with 50% requiring intensive care and 20% requiring inotropes. Older males had shorter LOS than younger males (P = 0.04), not seen in females. Treatment included intravenous glucocorticoids in 93%, intravenous immunoglobulins (IVIG) in 77%, Anakinra in 11%, and infliximab in 1.8%. Biomarkers correlated poorly with trajectories that peaked at different times. C-reactive protein peaked first after median 1.3 days postadmission; while LFT's and neutrophils peaked after 3 days. Age had a large effect on some biomarkers, with older children having larger troponin and ferritin, and lower lymphocytes and platelets. Cumulative dose of glucocorticoids and IVIG had a statistically significant effect on some biomarkers, but effect size was small. Conclusions: The heterogenous nature of PIMS-TS highlights the importance of a multidisciplinary approach. Worse inflammatory markers in older children within our cohort may be an indication of a different disease process occurring at different ages. Future work to investigate the association between age and troponin and ferritin in hyperinflammatory states is warranted.

We aimed to evaluate clinical and echocardiographic features of the children diag- nosed with multisystem inflammatory syndrome related to severe acute respiratory syndrome coronavirus-2 infection and determine early and mid-term cardiovascular outcomes.

We retrospectively evaluated 38 children who were diagnosed with multisystem inflammatory syndrome in our hospital between November 2020 and November 2021. Cardiovascular evaluations were performed during hospitalization, at the first, the second, and the third months after discharge, and then cardiac evaluation was repeated at 3-month intervals until a median of 24 weeks (range: 9-56 weeks).

The mean age of patients was 9.6 years and 25 patients had cardiovascular involve- ment. Echocardiography showed that there was left ventricular dysfunction in 11 cases and any coronary abnormalities in 11 cases on admission. Cardiovascular involvement was most fre- quently seen in patients older than 10 years and of male sex. Severe clinical courses occurred in half of them. The mortality rate was 2.6% during hospitalization. At discharge, complete recovery was achieved in 30 cases and partial recovery was seen in 6 cases; there were 1 case with ventricular dysfunction and 5 cases with coronary abnormalities. At the last polyclinic visit, there was no case with symptoms or myocardial dysfunction, there was only 1 case with persist- ing coronary aneurysms.

Cardiovascular abnormalities in patients with multisystem inflammatory syndrome show rapid resolution within the first month. We recommend long-term follow-up evaluation for coronary arteries.

With the rapid expansion of the COVID-19 pandemic, the disease burden and its consequences on the paediatric population has been progressively recognised. Although COVID-19 infection in children presents as asymptomatic to mild illness, instances of hyperinflammation and multi-organ involvement following the viral infection have been described. This condition, known as the multisystem inflammatory syndrome in children (MIS-C), has gained a wide global attention. Despite the global efforts to uncover the disease characteristics and management, a clear pathogenesis and a unified treatment regimen have not been reached yet. This paper tackles the epidemiology of the MIS-C, discusses its suggested pathogenesis, drives through its varying clinical presentations, and evaluates the different treatment regimens employed in managing MIS-C.

Patients with multisystem inflammatory disease in children (MIS-C) are at risk of developing shock. Our objectives were to determine independent predictors associated with development of delayed shock (≥3 hours from emergency department [ED] arrival) in patients with MIS-C and to derive a model predicting those at low risk for delayed shock.

We conducted a retrospective cross-sectional study of 22 pediatric EDs in the New York City tri-state area. We included patients meeting World Health Organization criteria for MIS-C and presented April 1 to June 30, 2020. Our main outcomes were to determine the association between clinical and laboratory factors to the development of delayed shock and to derive a laboratory-based prediction model based on identified independent predictors.

Of 248 children with MIS-C, 87 (35%) had shock and 58 (66%) had delayed shock. A C-reactive protein (CRP) level greater than 20 mg/dL (adjusted odds ratio [aOR], 5.3; 95% confidence interval [CI], 2.4-12.1), lymphocyte percent less than 11% (aOR, 3.8; 95% CI, 1.7-8.6), and platelet count less than 220,000/uL (aOR, 4.2; 95% CI, 1.8-9.8) were independently associated with delayed shock. A prediction model including a CRP level less than 6 mg/dL, lymphocyte percent more than 20%, and platelet count more than 260,000/uL, categorized patients with MIS-C at low risk of developing delayed shock (sensitivity 93% [95% CI, 66-100], specificity 38% [95% CI, 22-55]).

Serum CRP, lymphocyte percent, and platelet count differentiated children at higher and lower risk for developing delayed shock. Use of these data can stratify the risk of progression to shock in patients with MIS-C, providing situational awareness and helping guide their level of care.

Evidence for the treatment of multisystem inflammatory syndrome in children (MIS-C) is lacking. Anakinra, which targets IL-1-mediated inflammation, is reserved for refractory cases of MIS-C; however, its use in the treatment of MIS-C is not clearly established.

To examine a role for anakinra in MIS-C, we performed a single center observational cohort study of all MIS-C patients diagnosed at our children's hospital from May 15 to November 15, 2020. Demographics, clinical features, diagnostic testing, and cardiac function parameters were compared between MIS-C patients treated with intravenous immunoglobulin (IVIG) monotherapy and IVIG with anakinra (IVIG + anakinra).

Among 46 patients with confirmed MIS-C, 32 (70%) were in the IVIG + anakinra group, of which 9 (28%) were also given corticosteroids (CS). No patients were treated with anakinra alone. MIS-C patients in the IVIG + anakinra group were enriched in a CV shock phenotype (p = 0.02), and those with CV shock were treated with higher doses of anakinra for a longer duration. Furthermore, MIS-C patients in the IVIG + anakinra group exhibited improvements in fever and cardiac function with or without CS. No significant adverse events were observed, and no differences in IL-1β levels were found among MIS-C patients in the IVIG + anakinra group.

Anakinra treatment, which was co-administered with IVIG primarily in patients with severe MIS-C, was associated with improvements in fever and cardiac function, and demonstrated a favorable side-effect profile. These findings suggest a role for adjunctive anakinra in the treatment of severe MIS-C.

Studies on Multisystem Inflammatory Syndrome in Children (MIS-C) and Kawasaki Disease (KD) have yielded inconsistent results and are lacking in Asian and African countries. This study aimed to compare the laboratory and clinical features, short-term outcomes, and one-year follow-ups of a large cohort of MIS-C and KD patients.

Data from 176 MIS-C and 56 KD patients admitted to Tehran Children's Medical Center between January 2021 and January 2022 were collected. Patients were followed up until January 2023.

While lymphopenia and thrombocytopenia were more prevalent in MIS-C (73.2% vs. 20% in KD, p < 0.001), KD patients exhibited a higher median white blood cell count and prevalence of anemia, along with higher fibrinogen and erythrocyte sedimentation rate levels (p < 0.001, p < 0.001, p = 0.005, p < 0.001, respectively). MIS-C patients also exhibited lower ejection fraction, a greater occurrence of pericardial effusion, and a higher incidence of coronary aneurysms and ectasia, and ascites. Echocardiography after seven days of treatment showed a reduction in pathologies for both groups, but it was significant only for MIS-C. After one year, coronary artery abnormalities remained in only six cases.

In conclusion, this study highlights differences between MIS-C and KD, including laboratory indices as well as echocardiographic and abdominal ultrasound findings. These findings contribute valuable data on Iranian patients to the existing literature on this topic and have significant implications for accurate diagnosis and improved management of pediatric patients presenting with these conditions.

COVID-19 has caused significant worldwide morbidity and mortality. Congenital heart disease (CHD) is likely to increase vulnerability and understanding the predictors of adverse outcomes is key to optimising care.

Ascertain the impact of COVID-19 on people with CHD and define risk factors for adverse outcomes.

Multicentre UK study undertaken 1 March 2020-30 June 2021 during the COVID-19 pandemic. Data were collected on CHD diagnoses, clinical presentation and outcomes. Multivariable logistic regression with multiple imputation was performed to explore predictors of death and hospitalisation.

There were 405 reported cases (127 paediatric/278 adult). In children (age <16 years), there were 5 (3.9%) deaths. Adjusted ORs (AORs) for hospitalisation in children were significantly lower with each ascending year of age (OR 0.85, 95% CI 0.75 to 0.96 (p<0.01)). In adults, there were 24 (8.6%) deaths (19 with comorbidities) and 74 (26.6%) hospital admissions. AORs for death in adults were significantly increased with each year of age (OR 1.05, 95% CI 1.01 to 1.10 (p<0.01)) and with pulmonary arterial hypertension (PAH; OR 5.99, 95% CI 1.34 to 26.91 (p=0.02)). AORs for hospitalisation in adults were significantly higher with each additional year of age (OR 1.03, 95% CI 1.00 to 1.05 (p=0.04)), additional comorbidities (OR 3.23, 95% CI 1.31 to 7.97 (p=0.01)) and genetic disease (OR 2.87, 95% CI 1.04 to 7.94 (p=0.04)).

Children were at low risk of death and hospitalisation secondary to COVID-19 even with severe CHD, but hospital admission rates were higher in younger children, independent of comorbidity. In adults, higher likelihood of death was associated with increasing age and PAH, and of hospitalisation with age, comorbidities and genetic disease. An individualised approach, based on age and comorbidities, should be taken to COVID-19 management in patients with CHD.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a late systemic inflammatory response to a recent mild or asymptomatic coronavirus disease of 2019 infection. The pathophysiology is incompletely understood but it often features significant coagulopathy along with cardiac and endothelial dysfunction. Endothelial inflammation has been primarily described in acute coronavirus disease of 2019 infection, with less characterization in MIS-C. Here we describe novel findings of nearly universal severe and prolonged factor VIII (FVIII) and von Willebrand factor antigen elevations in an institutional cohort of patients with MIS-C ages younger than or 21 years old (N=31). All patients had elevated acute phase reactants and D-dimer at presentation and met published criteria for MIS-C. FVIII was high at presentation in 97% of patients but continued to rise during the ensuing weeks of treatment to a mean 429%, peaking on median day 17 of illness as an outpatient. FVIII levels were >600% in multiple patients. von Willebrand factor antigen was measured less frequently but showed similar trends. These escalations occurred amidst resolving cardiac dysfunction and acute phase reactant normalization and despite patients receiving multimodal anti-inflammatory treatments and aspirin and enoxaparin thromboprophylaxis. No thrombotic events occurred. Endothelial dysfunction represented by very elevated FVIII levels may persist longer than other acute phase reactants may reflect.

Multisystem inflammatory syndrome in children (MIS-C) is a severe disease with an unpredictable course and a substantial risk of cardiogenic shock. Our objectives were to (a) compare MIS-C phenotypes across the COVID-19 pandemic, (b) identify features associated with intensive care need and treatment with biologic agents.

Youth aged 0-18 years, fulfilling the World Health Organization case definition of MIS-C, and admitted to the Alberta Children's Hospital during the first four waves of the COVID-19 pandemic (May 2020-December 2021) were included in this cohort study. Demographic, clinical, biochemical, imaging, and treatment data were captured.

Fifty-seven MIS-C patients (median age 6 years, range 0-17) were included. Thirty patients (53%) required intensive care. Patients in the third or fourth wave (indicated as phase 2 of the pandemic) presented with higher peak ferritin (µg/l, median (IQR) = 1134 (409-1806) vs. 370 (249-629), P = 0.001), NT-proBNP (ng/l, median (IQR) = 12,217 (3013-27,161) vs. 3213 (1216-8483), P = 0.02) and D-dimer (mg/l, median (IQR) = 4.81 (2.24-5.37) vs. 2.01 (1.27-3.34), P = 0.004) levels, and higher prevalence of liver enzyme abnormalities (n(%) = 17 (68) vs. 11 (34), P = 0.02), hypoalbuminemia (n(%) = 24 (100) vs. 25 (81), P = 0.03) and thrombocytopenia (n(%) 18 (72) vs. 11 (34), P = 0.007) compared to patients in the first two waves (phase 1). These patients had a higher need of non-invasive/mechanical ventilation (n(%) 4 (16) vs. 0 (0), P = 0.03). Unsupervised clustering analyses classified 47% of the patients in the correct wave and 74% in the correct phase of the pandemic. NT-proBNP was the only significant contributor to the need for intensive care in all applied multivariate regression models. Treatment with biologic agents was significantly associated with peak CRP (mg/l (median, IQR = 240.9 (132.9-319.4) vs. 155.8 (101.0-200.7), P = 0.02) and ferritin levels (µg/l, median (IQR) = 1380 (509-1753) vs. 473 (280-296)).

MIS-C patients in a later stage of the pandemic displayed a more severe phenotype, reflecting the impact of distinct SARS-CoV-2 variants. NT-proBNP emerged as the most crucial feature associated with intensive care need, underscoring the importance of monitoring.

Background Multisystem inflammatory syndrome in children (MIS-C) is a new clinical observation that emerged during the coronavirus pandemic of 2019 (COVID-19) and has similar manifestations to Kawasaki disease and toxic shock syndrome. In this study, we aim to describe the characteristics of MIS-C patients in a single center in Jordan. Methods A retrospective analysis of electronic medical records of pediatric patients diagnosed with MIS-C at the pediatric rheumatology division of Queen Rania Children's Hospital, Amman, Jordan, between January 2021 and December 2022. Data collected included age, gender, clinical and laboratory data on presentation, and treatment options, which were compared in two different age groups. Results A total of 80 patients were included in this cohort (53 males and 27 females). The mean age at presentation was 84.4 months (ranging between nine months and 16 years). The most common presenting symptoms included fever (100%), abdominal pain (76.2%), skin rash (75%), conjunctivitis (72.5%), and mucosal changes (62.5%). Lymphopenia was present in 66.2% of patients. The majority of patients (98.7%) showed elevated C-reactive protein (CRP); 72 patients showed elevated erythrocyte sedimentation rate (ESR) (92.5%); ferritin was elevated in 70% of patients; the median fibrinogen level was 390 (interquartile range (IQR) 0.6-20) mg/dL; and the D-dimer level was 3.9 (IQR 0.6-20) mg/dL. Pericardial effusion was present in 23.8% of patients, and five patients (6.3%) had coronary artery dilatation. Conclusion To the best of our knowledge, this study is the first large case series of MIS-C in Jordan, with a wide spectrum of clinical presentation and evidence of hyperinflammation.

This study aims to review the available data regarding the central role of immunity in combating SARS-CoV-2 infection and in the generation of protection by vaccination against COVID-19 in different age groups. Physiologically, the immune response and the components involved in it are variable, both functionally and quantitatively, in neonates, infants, children, adolescents, and adults. These immunological differences are mirrored during COVID-19 infection and in the post-vaccination period. The outcome of SARS-CoV-2 infection is greatly dependent on the reaction orchestrated by the immune system. This is clearly obvious in relation to the clinical status of COVID-19 infection, which can be symptomless, mild, moderate, or severe. Even the complications of the disease show a proportional pattern in relation to the immune response. On the contrary, the commonly used anti-COVID-19 vaccines generate protective humoral and cellular immunity. The magnitude of this immunity and the components involved in it are discussed in detail. Furthermore, many of the adverse effects of these vaccines can be explained on the basis of immune reactions against the different components of the vaccines. Regarding the appropriate choice of vaccine for different age groups, many factors have to be considered. This is a cornerstone, particularly in the following age groups: 1 day to 5 years, 6 to 11 years, and 12 to 17 years. Many factors are involved in deciding the route, doses, and schedule of vaccination for children. Another important issue in this dilemma is the hesitancy of families in making the decision about whether to vaccinate their children. Added to these difficulties is the choice by health authorities and governments concerning whether to make children's vaccination compulsory. In this respect, although rare and limited, adverse effects of vaccines in children have been detected, some of which, unfortunately, have been serious or even fatal. However, to achieve comprehensive control over COVID-19 in communities, both children and adults have to be vaccinated, as the former group represents a reservoir for viral transmission. The understanding of the various immunological mechanisms involved in SARS-CoV-2 infection and in the preparation and application of its vaccines has given the sciences a great opportunity to further deepen and expand immunological knowledge. This will hopefully be reflected positively on other diseases through gaining an immunological background that may aid in diagnosis and therapy. Humanity is still in continuous conflict with SARS-CoV-2 infection and will be for a while, but the future is expected to be in favor of the prevention and control of this disease.

A new hyper-inflammatory syndrome in children was identified after SARS-CoV-2 infection as a post-infectious complication that is temporally associated with coronavirus disease (COVID-19). Fever, rash, conjunctival hyperemia, and gastrointestinal problems are all clinical manifestations of multisystem inflammatory syndrome in children. This condition, in some cases, causes multisystem involvement, affecting multiple organ systems and necessitating admission to a pediatric intensive care unit. Due to limited clinical studies, it is necessary to analyze the characteristics of the pathology in order to improve the management and long-term follow-up of high-risk patients. The objective of the study was to analyze the clinical and paraclinical characteristics of children diagnosed with MIS-C. The clinical study is a retrospective, observational, descriptive research work that includes patients diagnosed with MIS-C, temporally associated with coronavirus disease, and it contains clinical characteristics, laboratory data, and demographic information. The majority of patients had normal or slightly increased leukocyte counts, which were associated with neutrophilia, lymphocytopenia, and significantly elevated inflammatory markers, including high levels of C-reactive protein, fibrinogen, the erythrocyte sedimentation rate, serum ferritin, and IL 6 and elevated levels of the cardiac enzymes NT-proBNP and D-dimers, owing to the cardiovascular system involvement in the pro-inflammatory process. At the same time, renal system involvement led to raised creatinine and high proteinuria in association with hypoalbuminemia. This characteristic of the pro-inflammatory status as well as multisystem impairment are highly suggestive of the post-infection immunological reaction of the multisystem syndrome temporally associated with SARS-CoV-2 infection.