Risk Factors Associated with Intensive Care Admission in Children with Severe Acute Respiratory Syndrome Coronavirus 2-Related Multisystem Inflammatory Syndrome (MIS-C) in Latin America: A Multicenter Observational Study of the REKAMLATINA Network.

Background: Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 varies widely in its presentation and severity, with low mortality in high-income countries. In this study in 16 Latin American countries, we sought to characterize patients with MIS-C in the pediatric intensive care unit (PICU) compared with those hospitalized on the general wards and analyze the factors associated with severity, outcomes, and treatment received. Study Design: An observational ambispective cohort study was conducted including children 1 month to 18 years old in 84 hospitals from the REKAMLATINA network from January 2020 to June 2022. Results: A total of 1239 children with MIS-C were included. The median age was 6.5 years (IQR 2.5-10.1). Eighty-four percent (1043/1239) were previously healthy. Forty-eight percent (590/1239) were admitted to the PICU. These patients had more myocardial dysfunction (20% vs 4%; P < 0.01) with no difference in the frequency of coronary abnormalities (P = 0.77) when compared to general ward subjects. Of the children in the PICU, 83.4% (494/589) required vasoactive drugs, and 43.4% (256/589) invasive mechanical ventilation, due to respiratory failure and pneumonia (57% vs 32%; P = 0.01). On multivariate analysis, the factors associated with the need for PICU transfer were age over 6 years (aOR 1.76 95% CI 1.25-2.49), shock (aOR 7.06 95% CI 5.14-9.80), seizures (aOR 2.44 95% CI 1.14-5.36), thrombocytopenia (aOR 2.43 95% CI 1.77-3.34), elevated C-reactive protein (aOR 1.89 95% CI 1.29-2.79), and chest x-ray abnormalities (aOR 2.29 95% CI 1.67-3.13). The overall mortality was 4.8%. Conclusions: Children with MIS-C who have the highest risk of being admitted to a PICU in Latin American countries are those over age six, with shock, seizures, a more robust inflammatory response, and chest x-ray abnormalities. The mortality rate is five times greater when compared with high-income countries, despite a high proportion of patients receiving adequate treatment.

Vaccination against COVID-19 - risks and benefits in children.

Countries in Europe and around the world have taken varying approaches to their policies on COVID-19 vaccination for children. The low risk of severe illness from COVID-19 means that even small risks from vaccination warrant careful consideration. Vaccination appears to result in a decreased risk of severe illness including the paediatric multi-system inflammatory syndrome known to be associated with COVID-19. These risks have already decreased significantly with the emergence of the Omicron variant and its subvariants, and due to widespread population immunity through previous infection. There is a relatively high risk of myocarditis following second doses of mRNA vaccines in adolescent males, although the general course of this condition appears mild.   Conclusion: COVID-19 vaccination only provides a transient reduction in transmission. Currently, insufficient evidence exists to determine the impact of vaccination on post-acute COVID syndromes in children, which are uncommon. What is Known: • Vaccines against COVID-19 have significantly reduced morbidity and mortality around the world. • Whilst countries have universally recommended vaccines for adults and continue to recommend them for vulnerable populations, there has been more variability in recommendations for children. What is New: • In the setting of near universal existing immunity from infection, the majority of the initial benefit in protecting against severe illness has been eroded. • The risks of myocarditis following mRNA vaccination for children is low, but an important consideration given the modest benefits.

Prognostic factors for multisystem inflammatory syndrome in children: A systematic review and meta-analysis.

AIM: Multisystem inflammatory syndrome in children (MIS-C) is a novel condition that can occur post-SARS-CoV-2 infection in children and adolescents. There is a paucity of evidence on the prognostic factors associated with MIS-C. The aim of this systematic review and meta-analysis was to summarise the prognostic factors for MIS-C development. METHODS: Five databases were systematically searched from January 2020 to May 2023 for studies reporting on prognostic factors for MIS-C using multivariable regression models. Random-effects meta-analyses were conducted to pool odds ratios for each prognostic factor. Risk of bias was rated using QUIPS and the GRADE framework was used to assess the certainty of evidence for each unique factor. RESULTS: Twelve observational studies (N = 18 024) were included, and 13 unique prognostic factors were amenable to meta-analysis. With moderate certainty, age <12 years, male sex and Black race probably increase the risk of MIS-C. Malignancy and underlying respiratory disease probably decrease the risk of MIS-C. Low-certainty evidence suggests that Asian race may increase the risk of MIS-C, and comorbidity may decrease the risk of MIS-C. CONCLUSION: Current literature presents several prognostic factors related to MIS-C following SARS-CoV-2 infection. Further research is necessary to elucidate the pathophysiologic mechanisms related to MIS-C.

Lower Risk of Multisystem Inflammatory Syndrome in Children With the Delta and Omicron Variants of Severe Acute Respiratory Syndrome Coronavirus 2.

Little is known about the risk of multisystem inflammatory syndrome in children (MIS-C) with different severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants. In southeast England, MIS-C rates per confirmed SARS-CoV-2 infections in children aged 0-16 years were 56% lower (rate ratio [RR], 0.34 [95% confidence interval {CI}, .23-.50]) during prevaccine Delta, 66% lower (RR, 0.44 [95% CI, .28-.69]) during postvaccine Delta, and 95% lower (RR, 0.05 [95% CI, .02-.10]) during the Omicron period.

Three-Dimensional Echocardiography and Global Longitudinal Strain in Follow-Up After Multisystem Inflammatory Syndrome in Children: Six-Month, Single-Center, Prospective Study.

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

SARS-CoV-2 variants and the risk of pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 among children in Germany.

PURPOSE: To investigate the relationship between the risk of pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) in children and the predominance of different SARS-CoV-2 variants of concern (VOC) over time. METHODS: In relation to the Alpha, Delta, and Omicron VOC phases of the pandemic, the risk of developing PIMS-TS was calculated by analyzing data for rtPCR-confirmed SARS-CoV-2 infections reported to the German statutory notification system, along with data captured by a separate, national PIMS-TS registry. Both overall infection rates and age group-specific ratios of PIMS-TS during the different pandemic phases were calculated using the Alpha period as the baseline. RESULTS: The PIMS-TS rate changed significantly over time. When the Alpha VOC was dominant [calendar week (CW) 11 in March-CW 31 in August 2021], the PIMS-TS rate was 6.19 [95% confidence intervals (95% CI) 5.17, 7.20]. When Delta prevailed (CW 32 in August 2021-CW 4 in January 2022), the rate decreased to 1.68 (95% CI 1.49, 1.87). During the Omicron phase (CW 5 in January-CW 16 in April 2022), the rate fell further to 0.89 (95% CI 0.79, 1.00). These changes correspond to a decreased PIMS-TS rate of 73% (rate ratio 0.271, 95% CI 0.222; 0.332) and 86% (rate ratio 0.048, 95% CI 0.037; 0.062), respectively, in comparison to the Alpha period. Rate ratios were nearly identical for all age groups. CONCLUSION: The data strongly suggest an association between the risk for PIMS-TS and the prevailing VOC, with highest risk related to Alpha and the lowest to Omicron. Given the uniformity of the decreased risk across age groups, vaccination against SARS-CoV-2 does not appear to have a significant impact on the risk of children developing PIMS-TS.

Multisystem inflammatory syndrome in children associated with Bacille Calmette-Guérin scar: a case presentation.

BACKGROUND: During Coronavirus disease of 2019 (COVID-19) pandemic, the WHO reported a noticeable increase in Kawasaki disease prevalence in countries where Kawasaki disease is rare. This newly seen disease, unlike typical Kawasaki disease, tends to appear at a later age, has prominent gastrointestinal findings, higher rates of myocarditis and coronary artery involvement and a greater need for admission to the intensive care unit (ICU). Induration of the Bacillus Calmette-Guerin (BCG) scar is a rare finding seen in multisystem inflammatory syndrome (MIS-C). This is the second reported case of erythema and induration of the BCG scar in a 1-year-old boy with MIS-C. CASE PRESENTATION: The Arabic boy presented with high resistant fever, nausea/vomiting, diarrhea, erythematous lips, and conjunctivitis. He later developed induration of his BCG scar, diffuse rash and desquamation on fingers and toes. He had a history of COVID-19 exposure as his IgG antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were positive. Based on his clinical findings and repeated lab results, he was diagnosed with MIS-C with Kawasaki features and treated with intravenous immune globulin (IVIG) followed by methylprenisolone and aspirin. CONCLUSIONS: Reaction at the BCG inoculation site is not a diagnostic criteria for Kawasaki, but it is seen clinically in 30-50% of the patients. We report the case of a 1-year-old boy diagnosed with MIS-C presenting with erythema and induration of BCG scar. Further studies are needed to explore this clinical presentation, especially in the countries that have BCG vaccination programs, and to determine the mechanisms of MIS-C.

Cardiac Magnetic Resonance Follow-Up of Children After Pediatric Inflammatory Multisystem Syndrome Temporally Associated With SARS-CoV-2 With Initial Cardiac Involvement.

BACKGROUND: Pediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) is an inflammatory disease occurring in a small minority of children a few weeks after acute infection. Cardiac manifestations are common, but little is known about the potentially persistent heart changes after PIMS-TS. PURPOSE: To analyze the frequency and type of myocardial complications of PIMS-TS with initial cardiac involvement assessed with cardiac magnetic resonance imaging (MRI), including parametric imaging, performed 3 months after hospitalization. STUDY TYPE: Retrospective. POPULATION: Nineteen consecutive children (median age 10 years, interquartile range (IQR) 10-15 years, 74% male). FIELD STRENGTH/SEQUENCE: Balanced steady state free precession (bSSFP, cine imaging), modified Look-Locker (T1 mapping), T2-prepared bSSFP (T2-mapping), dark-blood T2-weighted turbo spin echo with fat suppression and phase sensitive inversion recovery (late gadolinium enhancement (LGE)) sequences at 1.5 T. ASSESSMENT: Patients were scanned after a median of 99 days (IQR 89-104 days) from the diagnosis. MR data were reviewed by three independent observers, with 13, 2, and 5 years' experience in cardiac MRI. Pre- and post-contrast T1, T2, extra-cellular volume, and T2 signal intensity (T2 SI) ratio were calculated. Diagnosis of acute myocarditis was based on modified Lake Louise criteria. Cardiac MRI parameters were compared, where possible, to previously published pediatric normal values. STATISTICAL TESTS: Interclass correlation coefficient and Bland-Altman repeatability analysis. A P-value <0.05 was considered statistically significant. RESULTS: Despite cardiac involvement including decreased left ventricular ejection fraction (LVEF) (median LVEF = 47%, IQR 43%-53%) and increased troponin I (median 101 ng/mL, IQR 50-661 ng/mL) during hospitalization, there were no persistent cardiac changes observed in cardiac MR at follow-up. All patients had normal size and function of the left ventricle and normal precontrast T1 and T2 relaxation times. There were no signs of LGE. Persistent, mild pericardial effusion (8-9 mm) was found in three (16%) patients. DATA CONCLUSION: There were no persistent changes on cardiac MRI in a group of children approximately 3 months post hospitalization due to PIMS-TS with cardiac involvement. This supports the hypothesis that cardiac involvement during PIMS-TS is a form of transient inflammatory response rather than direct and potentially persistent injury from the virus. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.

Risk for severe outcomes of COVID-19 and PIMS-TS in children with SARS-CoV-2 infection in Germany.

Although children and adolescents have a lower burden of SARS-CoV-2-associated disease compared to adults, assessing the risk for severe outcomes among SARS-CoV-2-infected children remains difficult due to a high rate of undetected cases. We combine data from three data sources - a national seroprevalence study (the SARS-CoV-2 KIDS study), the nationwide, state-based reporting system for PCR-confirmed SARS-CoV-2 infections in Germany, and a nationwide registry on children and adolescents hospitalized with either SARS-CoV-2 or pediatric inflammatory multisystem syndrome (PIMS-TS, also known as MIS-C) - in order to provide estimates on the risk of hospitalization for COVID-19-related treatment, intensive care admission, and death due to COVID-19 and PIMS-TS in children. The rate of hospitalization for COVID-19-related treatment among all SARS-CoV-2 seropositive children was 7.13 per 10,000, ICU admission 2.21 per 10,000, and case fatality was 0.09 per 10,000. In children without comorbidities, the corresponding rates for severe or fatal disease courses were substantially lower. The lowest risk for the need of COVID-19-specific treatment was observed in children aged 5-11 without comorbidities. In this group, the ICU admission rate was 0.37 per 10,000, and case fatality could not be calculated due to the absence of cases. The overall PIMS-TS rate was 2.47 per 10,000 SARS-CoV-2 infections, the majority being children without comorbidities. CONCLUSION: Overall, the SARS-CoV-2-associated burden of a severe disease course or death in children and adolescents is low. This seems particularly the case for 5-11-year-old children without comorbidities. By contrast, PIMS-TS plays a major role in the overall disease burden among all pediatric age groups. WHAT IS KNOWN: • SARS-CoV-2-associated burden of disease in children is considered to be low, but accurate risk estimates accounting for clinically undiagnosed infections are lacking. • Asymptomatic SARS-CoV-2 infections are common in children. WHAT IS NEW: • We provide risk estimates for hospitalization for COVID-19-related treatment, ICU admission, death from COVID-19, and PIMS-TS for children with SARS-CoV-2 infections by pooling different data sources. • The risk for PIMS-TS exceeds the risk for severe COVID-19 in all age groups; the risk for severe COVID-19 is the lowest in 5-11 years old.

Acute abdomen in multisystem inflammatory syndrome in children: A systematic review.

AIM: Multisystem inflammatory syndrome in children (MIS-C), a rare severe complication of SARS-CoV-2 infection, has been recently reported to mimic acute abdomen and lead to surgical interventions, posing challenges for clinicians. In this systematic review, we evaluated the rate of acute abdomen and abdominal surgical emergencies in children with MIS-C. METHODS: Systematic review of all MIS-C cases presented with acute abdomen. RESULTS: A total of 385 patients with MIS-C, from 38 studies, were included. Gastrointestinal manifestations were prominent in 233/385 (60.5%) children. Acute abdomen was noted in 72/385 (18.7%) of MIS-C cases and in 72/233 (30.9%) of MIS-C cases with gastrointestinal symptoms. Final diagnoses were mostly non-surgical (55/72, 76.4%), such as mesenteric lymphadenitis (23/72, 31.9%), terminal ileitis/ileocolitis (19/72, 26.4%), free abdominal fluid/ascites (8/72, 11.1%) and paralytic ileus (3/72, 4.2%). Laparotomy was performed in 35/72 (48.6%) of children with MIS-C, and acute abdomen and was proven unnecessary in 18/35 (51.4%) cases. True abdominal surgical emergencies, such as appendicitis and obstructive ileus, were confirmed in 17/72 (23.6%) cases. CONCLUSION: MIS-C often presents with acute abdomen, mostly due to non-surgical intestinal inflammatory pathology. However, surgical complications occur in patients with MIS-C; therefore, a high index of suspicion should remain.

COVID-19 in children. II: Pathogenesis, disease spectrum and management.

The global disruption of the COVID-19 pandemic has impacted the life of every child either directly or indirectly. This review explores the pathophysiology, immune response, clinical presentation and treatment of COVID-19 in children, summarising the most up-to-date data including recent developments regarding variants of concern. The acute infection with SARS-CoV-2 is generally mild in children, whilst the post-infectious manifestations, including paediatric inflammatory multisystem syndrome temporally associated with SARS-CoV-2 (PIMS-TS) and 'long COVID' in children, are more complex. Given that most research on COVID-19 has focused on adult cohorts and that clinical manifestations, treatment availability and impacts differ markedly in children, research that specifically examines COVID-19 in children needs to be prioritised.

Takotsubo syndrome as a cardiac manifestation of multisystem inflammatory syndrome in children.

Cases of severe heart damage in patients presenting with multisystem inflammatory syndrome in children are one of the most intriguing phenomena during the coronavirus disease of 2019 pandemic. The pathophysiology of myocardial changes in the course of this syndrome has not been fully understood yet. We present a case of a child with multisystem inflammatory syndrome in children and with cardiac changes corresponding to Takotsubo syndrome.

Cardiac pathology and outcomes vary between Kawasaki disease and PIMS-TS.

Overlapping clinical features promoted the discussion of whether Kawasaki disease (KD) and PIMS-TS share pathophysiological features and disease outcomes. Medical records from English patients with KD (2015-02/20, N = 27) and PIMS-TS (02/2020-21, N = 34) were accessed to extract information. Children with PIMS-TS were older and more frequently of minority ethnicity background. They patients more commonly exhibited cytopenias and hyperferritinemia, which associated with diffuse cardiac involvement and functional impairment. In some PIMS-TS cases, cardiac pathology developed late, but outcomes were more favorable. In both, KD and PIMS-TS, baseline coronary diameter was a predictor of outcomes. PIMS-TS treatment more frequently included respiratory and cardiovascular support, and corticosteroids with IVIG. Cardiac involvement in PIMS-TS may be the result of a cytokine storm. Though more severe and diffuse when compared to KD, cardiac involvement of PIMS-TS has a more favorable prognosis, which may, after recovery, mitigate the need for long-term follow up.

Distinctive Features of Kawasaki Disease Following SARS-CoV-2 Infection: a Controlled Study in Paris, France.

BACKGROUND: An outbreak of multisystem inflammatory syndrome in children, including Kawasaki disease (KD), emerged during COVID-19 pandemic. We explored whether Kawasaki-like disease (KD), when associated with confirmed SARS-CoV-2 infection, has specific characteristics. METHODS: We included children and adolescents with KD criteria admitted in the department of general pediatrics of a university hospital in Paris, France, between January 1, 2018, and May 26, 2020. The incidence of KD was compared between the outbreak and a pre-outbreak control period (January 1, 2018, to April 25). Characteristics of patients with positive SARS-CoV-2 testing (KD-SARS-CoV-2) were compared to those of the pre-outbreak period (classic KD). RESULTS: A total of 30 and 59 children with KD were admitted during the outbreak and pre-outbreak periods, respectively (incidence ratio 13.2 [8.3-21.0]). During the outbreak, 23/30 (77%) children were diagnosed as KD-SARS-CoV-2. When compared with patients with classic KD, those with KD-SARS-CoV-2 were more frequently of sub-Saharan African ancestry (OR 4.4 [1.6-12.6]) and older (median 8.2 vs. 4.0 years, p < 0.001), had more often initial gastrointestinal (OR 84 [4.9-1456]) and neurological (OR 7.3 [1.9-27.7] manifestations, and shock syndrome (OR 13.7 [4.2-45.1]). They had significantly higher CRP and ferritin levels. Noticeably, they had more frequently myocarditis (OR 387 [38-3933]). CONCLUSIONS: Children and adolescents with KD-SARS-CoV-2 have specific features when compared with those with classic KD. These findings should raise awareness and facilitate the study of their pathogenesis.

The inflammatory markers of multisystem inflammatory syndrome in children (MIS-C) and adolescents associated with COVID-19: A meta-analysis.

To conduct a systematic review and meta-analysis to characterize inflammatory markers in comparisons of multisystem inflammatory syndrome in children (MIS-C) versus severe/non-severe COVID-19, severe MIS-C versus non-severe MIS-C, and among age groups of MIS-C. Nine databases were searched for studies on inflammatory markers of MIS-C. After quality checks, data were pooled using a fixed or random effects model. Inflammatory markers included white blood cell count (WBC) or leukocytes, absolute lymphocyte count (ALC), absolute neutrophil count (ANC), platelet count (PLT), C-reactive protein (CRP), procalcitonin (PCT), ferritin, D-dimer, lactate dehydrogenase (LDH), fibrinogen, and erythrocyte sedimentation rate (ESR) for comparisons by severity and age. Twenty-one studies with 1735 participants yielded 787 MIS-C patients. Compared to non-severe COVID-19 patients, MIS-C patients had lower ALC and higher ANC, CRP, and D-dimer levels. Compared to severe COVID-19 patients, MIS-C patients had lower LDH and PLT counts and higher ESR levels. Severe MIS-C patients had higher levels of WBC, ANC, CRP, D-dimer, and ferritin than non-severe MIS-C patients. For MIS-C, younger children (0-5 years) had lower CRP and ferritin levels than middle-aged/older children/adolescents. Measurement of inflammatory markers might assist clinicians in accurate evaluation and diagnosis of MIS-C and the associated disorders.

Recurrent assessment of lymphocyte subsets in 32 patients with multisystem inflammatory syndrome in children (MIS-C).

BACKGROUND: Lymphopenia is a hallmark of multisystem inflammatory syndrome in children (MIS-C). We aimed to characterize lymphocyte subsets' shifts and their correlations with other severity markers of MIS-C. METHODS: In this prospective cross-sectional study, we performed peripheral lymphocyte phenotyping in 32 patients with MIS-C. We analyzed lymphocyte subsets at three time points of the disease: the acute (A), convalescent (B), and recovery (C) phases. Based on age-normalized lymphocyte counts, we distinguished two groups of patients: "the mild" (higher lymphocyte counts) and "the severe" (lower lymphocyte counts). In addition, we examined differences between these groups regarding other severity markers. RESULTS: In phase A, 84% of children had lymphopenia. Decreased absolute counts of CD3, CD4, and CD8 cells were observed in, respectively, 88%, 72%, and 84% of patients. The natural killer cells were decreased in 63% and CD19 in 59% of children. "The severe" group had significantly higher procalcitonin and troponin I levels and lower platelets and albumin. Moreover, "the severe" group had hypotension more frequently (73% vs. 20%, p = .008). In phase B, all lymphocyte counts increased, and 32% of children had lymphocytosis. The increase of CD3, CD4, and CD8 counts correlated with some laboratory severity markers (hemoglobin, procalcitonin, D-dimer, lactate dehydrogenase, N-terminal prohormone of brain natriuretic peptide, albumin), but not with steroid use. In phase C, most children had normal lymphocyte counts. CONCLUSIONS: Substantial shifts in lymphocyte counts during MIS-C apply most to T lymphocytes and correlate with the disease severity markers, particularly hypotension prevalence. A proportion of children with MIS-C develops transient lymphocytosis during convalescence.

Multi-system inflammatory syndrome in children & adolescents (MIS-C): A systematic review of clinical features and presentation.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a new phenomenon reported worldwide with temporal association with Covid-19. The objective of this paper is to evaluate reported cases in children and adolescents. From 1726 papers, 35 documented papers related to MIS-C cases identified 783 individual cases of MIS-C between March-June 2020; with 55% being male (n = 435) and a median age of 8.6 years (IQR, 7-10 years; range 3 months-20 years). Patients with MIS-C were noted to have a high frequency of gastrointestinal symptoms (71%) including abdominal pain (34%) and diarrhea (27%). Cough and respiratory distress were reported in 4.5% and 9.6% cases respectively. Blood parameters showed neutrophilia in 345/418 (83%) of cases and a high CRP in 587/626 (94%). 362/619 (59%) cases were SARS-CoV-2 infection positive (serology or PCR) however only 41% demonstrated pulmonary changes on chest imaging. Severity of illness was high with 68% cases requiring intensive care admission; 63% requiring inotropic support; 244/783 (28%) cases needing some form of respiratory support (138 mechanically ventilated), and 31 required extra-corporeal membrane oxygenation. Treatment strategies included intravenous immunoglobulin (63%) and intravenous steroids (44%). 29 cases received Infliximab, 47 received IL1 (interleukin) receptor antagonist, and 47 received IL6-receptor antagonist. 12/783 (1.5%) children died. In summary, a higher incidence of gastrointestinal symptoms were noted in MIS-C. In contrast to acute Covid-19 infection in children, MIS-C appears to be a condition of higher severity with 68% of cases having required critical care support.

Multisystem inflammatory syndrome in children related to COVID-19: a systematic review.

An association between a novel pediatric hyperinflammatory condition and SARS-CoV-2 was recently published and termed pediatric inflammatory multisystem syndrome, temporally associated with SARS-CoV-2 (PIMS-TS) or multisystem inflammatory syndrome (in children) (MIS(-C)). We performed a systematic review and describe the epidemiological, clinical, and prognostic characteristics of 953 PIMS-TS/MIS(-C) cases in 68 records. Additionally, we studied the sensitivity of different case definitions that are currently applied. PIMS-TS/MIS(-C) presents at a median age of 8 years. Epidemiological enrichment for males (58.9%) and ethnic minorities (37.0% Black) is present. Apart from obesity (25.3%), comorbidities are rare. PIMS-TS/MIS(-C) is characterized by fever (99.4%), gastrointestinal (85.6%) and cardiocirculatory manifestations (79.3%), and increased inflammatory biomarkers. Nevertheless, 50.3% present respiratory symptoms as well. Over half of patients (56.3%) present with shock. The majority of the patients (73.3%) need intensive care treatment, including extracorporal membrane oxygenation (ECMO) in 3.8%. Despite severe disease, mortality is rather low (1.9%). Of the currently used case definitions, the WHO definition is preferred, as it is more precise, while encompassing most cases.Conclusion: PIMS-TS/MIS(-C) is a severe, heterogeneous disease with epidemiological enrichment for males, adolescents, and racial and ethnic minorities. However, mortality rate is low and short-term outcome favorable. Long-term follow-up of chronic complications and additional clinical research to elucidate the underlying pathogenesis is crucial. What is Known: • A novel pediatric inflammatory syndrome with multisystem involvement has been described in association with SARS-CoV-2. • To date, the scattered reporting of cases and use of different case definitions provides insufficient insight in the full clinical spectrum, epidemiological and immunological features, and prognosis. What is New: • This systematic review illustrates the heterogeneous spectrum of PIMS-TS/MIS(-C) and its epidemiological enrichment for males, adolescents, and racial and ethnic minorities. • Despite its severe presentation, overall short-term outcome is good. • The WHO MIS definition is preferred, as it is more precise, while encompassing most cases.

Cardiac markers of multisystem inflammatory syndrome in children (MIS-C) in COVID-19 patients: A meta-analysis.

OBJECTIVE: A meta-analysis of laboratory cardiac markers for multisystem inflammatory syndrome in children (MIS-C) was performed in patients with coronavirus disease 2019 (COVID-19). METHODS: Eight databases were searched until April 10, 2021, for studies on cardiac markers, including B-type natriuretic peptide (BNP)/N-terminal pro-BNP (NT-proBNP), troponin, aspartate aminotransferase (AST), in MIS-C patients. RESULTS: Of the 2583 participants enrolled in 24 studies, 1613 patients were diagnosed with MIS-C. MIS-C patients exhibited higher BNP levels than patients with non-severe COVID-19 [SMD (95% CI): 1.13 (0.48, 1.77), p < 0.05]. No significant differences in BNP levels were observed between patients with MIS-C and severe COVID-19 [SMD (95% CI): 0.29 (-0.07, 0.65), p = 0.117]. Comparisons of MIS-C patients to all COVID-19 patients revealed no significant differences in levels of troponin [SMD (95% CI): 0.13 (-0.07, 0.32), p = 0.212] or AST [SMD (95% CI): 0.10 (-0.11, 0.31), p = 0.336]. Compared to patients with non-severe MIS-C, those with severe MIS-C exhibited higher levels of BNP [SMD (95% CI): 0.26 (0.04, 0.48), p < 0.05], but no differences in troponin [SMD (95% CI): 0.05 (-0.06, 0.16) p = 0.387] or AST [SMD (95% CI): 0.19 (-0.34, 0.71), p = 0.483] were observed. Moreover, there was no significant difference in BNP [SMD (95% CI): -0.21 (-1.07, 0.64), p = 0.624] or troponin [SMD (95% CI): -0.07 (-0.45, 0.31), p = 0.710] between MIS-C with and without coronary artery abnormality. Sensitivity analyses were performed to assess stability. No publication bias was detected based on Begg's test. CONCLUSIONS: The key cardiac marker that showed differences between patients with MIS-C/non-severe COVID-19 and between patients with severe/non-severe MIS-C was BNP. Other markers, such as troponin and AST, did not exhibit notable differences in indicating cardiac injury between patients with MIS-C and COVID-19.

Mortality and clinical characteristics of multisystem inflammatory syndrome in children (MIS-C) associated with covid-19 in critically ill patients: an observational multicenter study (MISCO study).

BACKGROUND: The clinical presentation and severity of Multisystem Inflammatory Syndrome in Children associated with COVID-19 (MIS-C) is widespread and presents a very low mortality rate in high-income countries. This research describes the clinical characteristics of MIS-C in critically ill children in middle-income countries and the factors associated with the rate of mortality and patients with critical outcomes. METHODS: An observational cohort study was conducted in 14 pediatric intensive care units (PICUs) in Colombia between April 01, 2020, and January 31, 2021. Patient age ranged between one month and 18 years, and each patient met the requirements set forth by the World Health Organization (WHO) for MIS-C. RESULTS: There were seventy-eight children in this study. The median age was seven years (IQR 1-11), 18 % (14/78) were under one year old, and 56 % were male. 35 % of patients (29/78) were obese or overweight. The PICU stay per individual was six days (IQR 4-7), and 100 % had a fever upon arrival to the clinic lasting at least five days (IQR 3.7-6). 70 % (55/78) of patients had diarrhea, and 87 % (68/78) had shock or systolic myocardial dysfunction (78 %). Coronary aneurysms were found in 35 % (27/78) of cases, and pericardial effusion was found in 36 %. When compared to existing data in high-income countries, there was a higher mortality rate observed (9 % vs. 1.8 %; p=0.001). When assessing the group of patients that did not survive, a higher frequency of ferritin levels was found, above 500 ngr/mL (100 % vs. 45 %; p=0.012), as well as more cardiovascular complications (100 % vs. 54 %; p = 0.019) when compared to the group that survived. The main treatments received were immunoglobulin (91 %), vasoactive support (76 %), steroids (70.5 %) and antiplatelets (44 %). CONCLUSIONS: Multisystem Inflammatory Syndrome in Children due to SARS-CoV-2 in critically ill children living in a middle-income country has some clinical, laboratory, and echocardiographic characteristics similar to those described in high-income countries. The observed inflammatory response and cardiovascular involvement were conditions that, added to the later presentation, may explain the higher mortality seen in these children.