The "Golden Hours" Algorithm For the Management of the Multisystem Inflammatory Syndrome in Children (MIS-C)

Clinical presentation, diagnosis and management of multisystem inflammatory syndrome in children (MIS-C): a systematic review

BACKGROUND

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).

METHODS

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.

RESULTS

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.

CONCLUSION

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.

PROSPERO REGISTRATION NUMBER

CRD42020195823.

The evaluation of the burden of multisystem inflammatory syndrome in children on health economics

Objectives

This study aimed to evaluate the diagnostic tests and treatments applied in patients with multisystem inflammatory syndrome in children (MIS-C) and to determine the effect of the disease on health costs.

Patients and methods

This retrospective cohort study included 59 MIS-C patients (40 males, 19 females; mean age: 7.7±4.2 years; range, 4 months to 16.5 years) who were admitted and treated between April 1, 2020, and November 1, 2021. Demographic and clinical features with hospital costs and length of stay were retrospectively reviewed from the medical files and computerized system of the hospital. Direct medical care costs of items were calculated with the hospital perspective using a combination of microcosting technique (resource-based accounting method) and hospital list data. Cases were classified as mild, moderate, or severe, and the patients were divided into two groups: the mild group and the moderate-severe group. Classification was determined by the vasoactive inotropic score (VIS), degree of respiratory support, and evidence of organ damage.

Results

The mean age of the cases in the mild group was 6.5±3.7 years, and the mean age of the cases in the moderate-severe group was 9.2±4.3 years. Of 59 patients, 19 (32.2%) were followed up in the pediatric intensive care unit. The median duration of hospitalization in the hospital was 8 (interquartile range: 7-12) days. The total cost of the patients hospitalized with the diagnosis of MIS-C during the study period was 849,242.93$, and the mean cost per patient was 14,393.94±9,631.92$. In the distribution of the total cost of hospitalization according to expenses, the highest rate was pharmacy and blood products (51.99%) and IVIG costs (43.99%). While the mean total cost per person was 13,682.87±8,799.63$ in mild cases, it was 16,433.82±9,440.02$ in moderate-severe cases, and no statistically significant relationship was found between the two groups (p>0.05). There was no difference in the mean cost per patient between the cases with and without heart, lung, kidney, or neurologic involvement and advanced respiratory support (p>0.05). There was a strong positive correlation between the total costs and age (r=0.883, n=59, p<0.0001), with increased amount of costs with increased age.

Conclusion

In the study, no statistically significant correlation was found between the total cost of per person in the mild group and the moderate-severe group (p>0.05). This finding may be due to the wide use of IVIG in MIS-C treatment, in addition to low transfer rates to pediatric intensive care units due to high-flow nasal cannula usage.

Development of a biomarker signature using grating-coupled fluorescence plasmonic microarray for diagnosis of MIS-C

Multisystem inflammatory syndrome in children (MIS-C) is a rare but serious condition that can develop 4–6 weeks after a school age child becomes infected by SARS-CoV-2. To date, in the United States more than 8,862 cases of MIS-C have been identified and 72 deaths have occurred. This syndrome typically affects children between the ages of 5–13; 57% are Hispanic/Latino/Black/non-Hispanic, 61% of patients are males and 100% have either tested positive for SARS-CoV-2 or had direct contact with someone with COVID-19. Unfortunately, diagnosis of MIS-C is difficult, and delayed diagnosis can lead to cardiogenic shock, intensive care admission, and prolonged hospitalization. There is no validated biomarker for the rapid diagnosis of MIS-C. In this study, we used Grating-coupled Fluorescence Plasmonic (GCFP) microarray technology to develop biomarker signatures in pediatric salvia and serum samples from patients with MIS-C in the United States and Colombia. GCFP measures antibody-antigen interactions at individual regions of interest (ROIs) on a gold-coated diffraction grating sensor chip in a sandwich immunoassay to generate a fluorescent signal based on analyte presence within a sample. Using a microarray printer, we designed a first-generation biosensor chip with the capability of capturing 33 different analytes from 80 μL of sample (saliva or serum). Here, we show potential biomarker signatures in both saliva and serum samples in six patient cohorts. In saliva samples, we noted occasional analyte outliers on the chip within individual samples and were able to compare those samples to 16S RNA microbiome data. These comparisons indicate differences in relative abundance of oral pathogens within those patients. Microsphere Immunoassay (MIA) of immunoglobulin isotypes was also performed on serum samples and revealed MIS-C patients had several COVID antigen-specific immunoglobulins that were significantly higher than other cohorts, thus identifying potential new targets for the second-generation biosensor chip. MIA also identified additional biomarkers for our second-generation chip, verified biomarker signatures generated on the first-generation chip, and aided in second-generation chip optimization. Interestingly, MIS-C samples from the United States had a more diverse and robust signature than the Colombian samples, which was also illustrated in the MIA cytokine data. These observations identify new MIS-C biomarkers and biomarker signatures for each of the cohorts. Ultimately, these tools may represent a potential diagnostic tool for use in the rapid identification of MIS-C.

Ten-month follow-up of patients with covid-19 temporally related multi-system inflammatory syndrome in children: the experience of the children hospital of Palermo

BACKGROUND

In Sicily, the first wave of COVID-19 showed a low epidemic impact in paediatric population, while the second and the third waves had a higher impact on clinical presentation of COVID-19 in children and a significantly higher severe outcome in patients with multisystem inflammatory syndrome in children (MIS-C), with a frequent life-threatening progression.

METHODS

We describe a cohort of 22 Sicilian children (11 M; 11 F; age: 1.4-14 years), presenting with clinical features compatible with MIS-C. Patients with negative swab had a history of recent personal or parental infection.

RESULTS

The following diagnostic criteria were detected: fever (100%); cheilitis and/or pharyngeal hyperaemia (86%); latero-cervical lymphadenitis (82%); rash (73%); abdominal pain and/or vomiting and/or diarrhoea (64%); conjunctivitis (64%); hands and feet oedema (18%). 59% showed cardiac involvement (6 pericardial effusion; 8 mitral valve insufficiency; 4 insufficiency of two valves; 3 coronary artery lesions (CAL)). In all the patients, treatment was started within 72 h after the admission, with intravenous immunoglobulins (IVIG) (2 g/Kg/dose), methylprednisolone (2 mg/Kg/day in 73% of patients; 30 mg/Kg/day for 3 days, followed by 2 mg/Kg/day in 27% of patients). Two patients were treated with enoxaparin. Two patients with shock, were additionally treated with vasoactive drugs, albumin, diuretics. Cardiac involvement evolved into the complete resolution of lesions in most of the patients. All the patients were included in a follow-up, to investigate on clinical outcome and resolution of organ involvement. Cardiac valve insufficiency persisted only in 18% of children, CAL persisted only in 33% of children with coronary involvement, however without the evolution into aneurisms.

CONCLUSIONS

The preferred treatment strategy was more aggressive at the diagnosis of MIS-C, to block the cytokine cascade. Most of our patients, in fact, received a first-line treatment with IVIG and steroids. This approach could explain the favourable prognosis, the rapid restoring of cardiac function also in patients with MAS or shock, and the good outcome during the 10 months follow-up in all the patients.

Clinical and laboratory characteristics of multisystem inflammatory syndrome in children associated with COVID-19 in Egypt: A tertiary care hospital experience

AIM

We aimed to evaluate MIS-C patients' clinical manifestations, laboratory test results and mortality outcomes in an Egyptian tertiary care university hospital.

METHODS

We conducted a 12 month cross-sectional study in a tertiary-care university children's hospital. All paediatric patients (1 month to 16 years old) who met the CDC criteria for MIS-C were enrolled in the study. We assessed patients' clinical presentations, complications, treatments, imaging studies, laboratory test results and outcomes. The baseline clinical and laboratory findings of survivors and non-survivors were compared.

RESULTS

Of 45 MIS-C patients, 24 (53.3%) were males, and the median (interquartile range) age was 4 (1.25-10) years. All patients had fever, 64.4% had respiratory manifestations, 48.9% presented with coma, 44.4% presented with shock, 33.3% presented with seizures, 31.1% had abdominal pain, 28.9% had vomiting and 22.2% presented with cerebrovascular stroke. A total of 15 (33.3%) patients died, and the non-survivors had a significantly higher incidence of respiratory manifestations (P = 0.028), shock (P = 0.034), cerebrovascular stroke (P = 0.043) and seizures (P = 0.044) as compared to the survivors. In addition, the serum levels of ferritin (P = 0.047), alanine aminotransferase (P = 0.047) and aspartate aminotransferase (P = 0.05) were significantly higher in the non-survivors as compared to the survivors.

CONCLUSIONS

Based on our findings, MIS-C associated with COVID-19 is a potentially fatal illness. Hospitalised patients with MIS-C often have multi-organ injuries affecting the respiratory, cardiovascular, gastrointestinal and neurological systems. The deceased are more likely to exhibit respiratory manifestations, shock, cerebrovascular stroke, seizures and elevated serum levels of ferritin and liver enzymes.

Cardiovascular Outcomes in Children with Multisystem Inflammatory Syndrome Treated with Therapeutic Plasma Exchange

Background: Multisystem inflammatory syndrome in children is a new, rare, post-infectious complication of SARS-CoV-2 infection in children. The aim of this study was to display the role of therapeutic plasma exchange on cardiovascular outcomes in children with multisystem inflammatory syndrome. Methods: This study included children who met the diagnostic criteria for multisystem inflammatory syndrome and who were admitted to the intensive care unit. This is a prospective single-center study conducted between August 2020 and September 2021. Subjects had cardiac involvement which was defined as elevated troponin I, abnormal electrocardiographic and echocardiographic findings. Patients were followed by a pediatric cardiologist throughout the intensive care unit stay and after discharge for 12 months. Patients were divided into two groups which received therapeutic plasma exchange and which did not. Results: 38 children were included in this study. There were 16 patients in the no plasma exchange group and 22 patients in the plasma exchange group. The two groups were similar in age, sex, leucocyte, thrombocyte count, neutrophil percentage, hemoglobin, C-reactive protein, erythrocyte sedimentation rate, alanine aminotransferase, albumin, ferritin, fibrinogen, D-dimer, IL-6, troponin I, number of electrocardiographic abnormalities and patients with mitral valve regurgitation detected at admission (p > 0.05). There was no significant difference between the two groups in terms of duration of normalization of electrocardiographic abnormalities and disappearance of mitral valve regurgitation (p > 0.05). Duration of normalization of troponin I (2, IQR 1−4, versus 5, IQR 3−9 days; p = 0.044) and length of hospital stay (7, IQR 6−10, versus 13, 8−20 days; p = 0.001) was longer in the plasma exchange group. Conclusions: We did not observe any significant improvement in children having undergone plasma exchange as compared to children who did not. On the opposite, their length of hospital stay and time to troponin I normalisation were even longer. Some baseline differences in cardiac attainment severity may partly explain this finding.

A retrospective comparative analysis of factors affecting the decision and outcome of initial intravenous immunoglobulin alone or intravenous immunoglobulin plus methylprednisolone use in children with the multisystem inflammatory syndrome

BACKGROUND

For children with the multisystem inflammatory syndrome(MIS-C), intravenous immunoglobulins (IVIG) with or without methylprednisolone are the most effective treatment. In this study, IVIG combined with methylprednisolone was compared to IVIG used alone in children with MIS-C.

METHODS

This retrospective cohort study was carried out between April 1, 2020, and November 1, 2021. This study covered all children with MIS-C. According to whether they received IVIG alone or IVIG with methylprednisolone as an initial treatment for MIS-C, the patients were split into two groups. The IVIG dosage for the patients in group I was 2 gr/kg, whereas the IVIG dosage for the patients in group II was 2 gr/kg + 2 mg/kg/day of methylprednisolone. These two groups were contrasted in terms of the frequency of fever, length of hospital stay, and admission to the pediatric intensive care unit.

RESULTS

The study comprised 91 patients who were diagnosed with MIS-C and were under the age of 18. 42 (46.2%) of these patients were in the IVIG alone group (group I), and 49 (53.8%) were in the IVIG + methylprednisolone group (group II). Patients in group II had a severe MIS-C ratio of 36.7%, which was substantially greater than the rate of severe MIS-C patients in group I (9.5%) (p 0.01). When compared to group I (9.5%), the rate of hypotension was considerably higher in group II (30.6%) (p = 0.014). Additionally, patients in group II had considerably higher mean serum levels of C-reactive protein. The incidence of fever recurrence was 26.5% in group II and 33.3% in group I, however the difference was not statistically significant (p > 0.05).

CONCLUSIONS

The choice of treatment for patients with MIS-C should be based on an individual evaluation. In MIS-C children with hypotension and/or with an indication for a pediatric intensive care unit, a combination of IVIG and methylprednisolone may be administered. For the treatment modalities of children with MIS-C, however, randomized double-blind studies are necessary.

Early is superior to late plasma exchange for severe multisystem inflammatory syndrome in children

BACKGROUND

Multisystem inflammatory syndrome in children (MIS-C) can be life threatening in severe cases because of uncontrolled inflammation and multi-organ failure. In this study, we report the effect of plasma exchange in the treatment of MIS-C and to emphasize the effect of its early application on outcome.

METHOD

In this retrospective observational study, the medical records of children with severe MIS-C admitted to pediatric intensive care unit (PICU) between April 2020 and January 2021 were reviewed. Severe MIS-C patients were treated according to protocol consisting of plasma exchange (PE), intravenous immune globulin, steroids, and anakinra which we called the "PISA" protocol referring to the initials. The patients were divided into two groups as early plasma exchange (E-PE) and late plasma exchange (L-PE) according to the elapse time between hospital admission and the administration of PE. Groups were compared in terms of outcome variables. Primary study outcome was 28-day mortality. Secondary outcome variables were acute phase response time, length of immunomodulatory treatment, frequency of patients requiring mechanical ventilation (MV) and inotropic support, length of inotropic support and MV, length of hospital and PICU stays.

RESULTS

Eighteen pediatric patients with MIS-C were included in the study. Seventeen (95%) of the patients presented with decompensated shock and required inotropic support. One of the 17 patients needed extracorporeal membrane oxygenation support (ECMO) PISA protocol was used in all patients. There was no mortality in the E-PE group while the mortality rate was 20% in the L-PE group. Acute phase reactant response was faster in the E-PE group and immunomodulatory treatments could be reduced earlier; the frequency of patients requiring inotropic and mechanical ventilation (MV) support was lower in the E-PE group; the duration of inotropic support, duration of MV, and length of stay in hospital and PICU were significantly shorter in the E-PE group.

CONCLUSION

We suggest that in selected cases, timely administration of PE is a beneficial rescue therapy for MIS-C related hyperinflammation presenting with severe cardiovascular collapse.

COVID-19 in children: an approach for multisystem inflammatory syndrome

Background and objectives

Children suffering from coronavirus disease (COVID-19) usually present with mild symptoms and show lower mortality rates than adults. However, there have been several recent reports of more severe hyperinflammatory presentation in pediatric COVID-19 patients. This review article aims to summarize the current literature available on the main clinical features and management approaches of multisystem inflammatory syndrome in children (MIS-C).

Methods

The authors searched different indexing databases for observational and interventional studies using search terms including “Coronavirus, COVID-19, pediatric, MIS-C, Kawasaki, and inflammation.” The retrieved publications were further assessed for relevance to the topic. Only relevant articles were included in writing this review article.

Main body

Multisystem inflammatory syndrome in children (MIS-C) is a hyperinflammatory syndrome temporally related to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in pediatrics. It is characterized by persistent fever, rash, elevated inflammatory markers, and multiorgan failure with increasing rates of cardiovascular and gastrointestinal involvement. The exact pathophysiologic mechanisms of MIS-C are still unknown, but it is postulated to be due to an exaggerated immune response to SARS-CoV-2 infection. Multisystem inflammatory syndrome in children is diagnosed by exclusion of other underlying causes of organ failure. There is a lack of clinical evidence on the management of MIS-C. The current guidelines depend mainly on expert opinion based on the management of other hyper-inflammatory syndromes in children. Patients suffering from MIS-C are treated with intravenous immunoglobulin (IVIg), corticosteroids, infliximab, tocilizumab, and anakinra.

Conclusions

Despite the growing reports on COVID-19 in children, there is still a lot to elucidate on the pathophysiology, diagnosis, and subsequent management of MIS-C. Further trials are needed to investigate new approaches to manage MIS-C. Specific evidence-based guideline for management of MIS-C should be tailored to the current available information on MIS-C.

Short-term Cardiovascular Complications of Multi-system Inflammatory Syndrome in Children (MIS-C) in Adolescents and Children

Purpose of Review

We provide the readers with a review of cardiac complications in children with multi-system inflammatory syndrome in children (MIS-C) and its short-term outcomes.

Recent Findings

Recent reports described the acute cardiac manifestations of MIS-C in children and provided a glimpse of the short-term outcomes.

Summary

Children with MIS-C have been reported to acutely have variable degrees of cardiac findings including abnormal cardiac enzymes, abnormal electrocardiographs, decreased systolic function, coronary artery abnormalities from coronary dilation to giant aneurysms, mitral valve regurgitation, tricuspid valve regurgitation, aortic valve insufficiency, pericardial effusion, diastolic dysfunction, abnormal cardiac strain, and abnormal cardiac MRI. The majority of these abnormalities resolved during short-term follow-up. Further studies are needed to assess if transient or persistent cardiac complications are associated with long-term adverse cardiac events in children with MIS-C.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40124-021-00258-5.