A cursed goodbye kiss from severe acute respiratory syndrome-coronavirus-2 to its pediatric hosts: multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children: A review

AIM

To comprehensively review the literature on multisystem inflammatory syndrome in children (MIS-C).

METHODS

Narrative review of relevant studies published between April 2020 and January 2024.

RESULTS

MIS-C is a SARS-CoV-2-related hyperinflammatory syndrome developing 2-6 weeks after COVID-19 in genetically susceptible individuals. Persisting fever, mucocutaneous manifestations, GI and cardiac involvement, together with lymphopenia and elevated inflammatory and cardiac markers are the main clinical features. It is believed to recognise some pathogenetic and clinical overlap with Kawasaki disease. New case definitions have been proposed after an assessment of the diagnostic performance of existing criteria; epidemiological criterion is however progressively losing its usefulness as the pandemic turns into an endemic and in the areas with the highest rates of COVID-19 vaccination. Current guidelines recommend both intravenous immunoglobulin and glucocorticoids in the first-line immunomodulatory treatment, mainly based on comparative retrospective cohorts; the actual role of biologics remains to be adequately established. Strict follow-up is mandatory, especially for those with severe cardiac involvement, as longitudinal studies evaluate the long-term evolution of cardiac damage.

CONCLUSION

In this paper, we review the epidemiological, pathogenetic, clinical and prognostic features of MIS-C, and outline the main questions which still remain unanswered after more than 3 years of research.

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.

Clinical Syndromes Related to SARS-CoV-2 Infection and Vaccination in Pediatric Age: A Narrative Review

This narrative review aims to report the main clinical manifestations, therapeutic strategies, outcomes, and complications of acute SARS-CoV-2 infection in childhood and to summarize the data relating the SARS-CoV-2 vaccination efficacy and safety in pediatric age. SARS-CoV-2 infection mostly occurs asymptomatically in the pediatric population, while multisystem inflammatory syndrome in children (MIS-C) represents the most severe coronavirus disease 2019 (COVID-19)-related illness, a life-threatening event with a high morbidity rate. After the development of SARS-CoV-2 vaccines and their subsequent approval in children, the rate of infection as well as the number of its related complications have shown a drastic decrease. Fully vaccinated children are protected from the risk of developing a severe disease and a similar protective role has been observed in the reduction of complications, in particular MIS-C. However, long-lasting immunity has not been demonstrated, booster doses have been required, and reinfection has been observed. With regards to vaccine safety, adverse events were generally mild to moderate in all age groups: local adverse events were the most commonly reported. Nevertheless, a potential association between SARS-CoV-2 vaccine and the subsequent development of inflammatory manifestations has been suggested. Myocarditis has rarely been observed following vaccination; it appeared to be more frequent among adolescent males with a mild clinical course leading to a complete recovery. SARS-CoV-2 vaccine-related MIS-C cases have been described, although a univocal definition and an exact time interval with respect to vaccination has not been reported, thus not establishing a direct causal link. Current evidence about COVID-19 vaccination in children and adolescents suggest that benefits outweigh potential risks. Long-term data collection of the post-authorization safety surveillance programs will better define the real incidence of SARS-CoV-2 vaccine-related complications in the pediatric population.

Stevens-Johnson syndrome and COVID-19: a case report with suspected multisystem inflammatory syndrome in children (MIS-C)

Introduction and importance

Symptoms similar to diseases such as Stevens-Johnson syndrome (SJS) and multisystemic inflammatory syndrome in children (MIS-C) were reported in pediatric coronavirus infections.

Case presentation

Here, we present a 4-year-old girl with coronavirus disease 2019 (COVID-19), an earlier diagnosis of SJS, and a final diagnosis of MIS-C.

Clinical discussion

Unlike the negative PCR test for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the positive serological test confirmed COVID-19.

Conclusion

The monitoring of this case indicated that higher coronavirus infection can delay immune reaction and cause symptoms similar to SJS.

Prognostic role of euthyroid sick syndrome in MIS-C: results from a single-center observational study

Background

Euthyroid sick syndrome (ESS) is characterized by low serum levels of free triiodothyronine (fT3) with normal or low levels of thyroid stimulating hormone (TSH) and free thyroxine (fT4) and is reported in different acute clinical situations, such as sepsis, diabetic ketoacidosis and after cardiac surgery. Our aim was to evaluate the predicting role of ESS for disease severity in patients with Multisystem Inflammatory Syndrome in children (MIS-C).

Methods

A single-centre observational study on consecutive patients with MIS-C. Before treatment clinical, and laboratory data were collected and, in a subset of patients, thyroid function tests were repeated 4 weeks later. Variables distribution was analyzed by Mann-Whitney U-test and correlations between different parameters were calculated by Spearman's Rho coefficient.

Results

Forty-two patients were included and 36 (85.7%) presented ESS. fT3 values were significantly lower in patients requiring intensive care, a strong direct correlation was shown between fT3 and Hb, platelet count and ejection fraction values. A significant inverse correlation was retrieved between fT3 levels and C-reactive protein, brain natriuretic peptide, IL-2 soluble receptor and S-100 protein. Subjects with severe myocardial depression (EF < 45%) had lower fT3 values than subjects with higher EF. The thyroid function tests spontaneously normalized in all subjects who repeated measurement 4 weeks after admission.

Conclusion

ESS is a frequent and transient condition in acute phase of MIS-C. A severe reduction of fT3 must be considered as important prognostic factor for severe disease course, with subsequent relevant clinical impact in the management of these patients.

Multi-Inflammatory Syndrome in Children (MIS-C) in 2023: Is It Time to Forget about It?

Multisystem inflammatory syndrome in children (MIS-C) is defined as a clinically serious condition requiring hospitalization involving fever, multi-system organ dysfunction, and an increase in inflammatory biomarkers. The syndrome was originally described as a post-infectious complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, which usually causes COVID-19. During the COVID-19 pandemic, not only did the virus undergo mutations but vaccines against SARS-CoV-2 were also developed. Both these conditions led to a decrease in the incidence of MIS-C. This narrative review summarizes the recent updates for MIS-C, particularly regarding the change in incidence, the link between the SARS-CoV-2 vaccine and MIS-C, and new updates of MIS-C treatments.

Six-month multidisciplinary follow-up in multisystem inflammatory syndrome in children: An Italian single-center experience

BACKGROUND

A severe multisystem inflammatory syndrome in children (MIS-C) related to SARS-CoV-2 has been described after infection. A limited number of reports have analyzed the long-term complications related to pro-inflammatory status in MIS-C. We evaluated multiorgan impairment at the 6-month follow-up in MIS-C.

METHODS

We enrolled 33 pediatric patients consecutively hospitalized for MIS-C and monitored for almost 6 months. The inter-relationship of patient's features and disease severity at admission with long term complications was studied by multivariate analysis.

RESULTS

Endo-metabolic derangement, cardiac injury, respiratory, renal and gastrointestinal manifestations and neurological involvement are part of the initial presentation. The most abnormalities appear to resolve within the first few weeks, without significant long term dysfunction at the 6-months follow-up, except for endocrine (non-thyroidal illness syndrome in 12.1%, insulin resistance in 21.2%) and neurological system (27.3% cognitive or psychological, behavioral, adaptive difficulties). Endocrine and heart involvement at admission represent a significant factor on the long term sequelae; however no association between severity score and long-term outcome was noted.

CONCLUSIONS

The severity of initial clinical presentation may be associated to organ domain, however it is not related to long term sequelae. The prevalent organ restoration supports a predominant indirect immune-mediated injury triggered by a systemic inflammatory response; however a direct damage due to the viral entry could be not excluded. Eventhought our preliminary results seem to suggest that MIS-C is not a long-term risk condition for children health, a longer follow-up is mandatory to confirm this hypothesis.