Emerging Insights Into the Pathophysiology of Multisystem Inflammatory Syndrome Associated With COVID-19 in Children

Incomplete Kawasaki disease with muscular weakness and bladder retention: a case report

BACKGROUND

Kawasaki disease (KD) is an acute systemic immune vasculitis affecting multiple organs and systems in children, and is prevalent in children under 5 years of age. Muscular weakness is a rare manifestation of KD, and only 11 pediatric patients with KD combined with muscular weakness have been reported, of which evidence of myositis was found in 2/3 of the patients, and 1/3 could not be explained by myositis, the mechanism of which is still unclear. Cases of KD combined with bladder retention are even more rare, and there has been only 1 case report of KD combined with bladder retention in a child with no previous underlying disease.

CASE PRESENTATION

We report a 22-month-old Asian child with incomplete Kawasaki disease (IKD) who initially presented with fever and progressive muscular weakness in the lower extremities, followed by the bladder and bowel retention abnormalities and rapid onset of heart failure, respiratory failure and shock. The child developed coronary artery ectasia (CAA) without the main clinical features of KD such as rash, conjunctival congestion, desquamation of the extremity endings, orofacial changes and enlarged lymph nodes in the neck. Creatine kinase and electromyography were normal. Temperature gradually normalized and muscle strength recovered slightly after intravenous immunoglobulin. The child could be helped to walk after 1 week of aspirin combined with steroid therapy.

CONCLUSIONS

We present the case of a 22-month-old child with IKD. The child began with progressive muscular weakness in the extremities, followed by the bladder and bowel retention abnormalities, and rapidly developed heart failure, respiratory failure, and shock. Despite early failure to detect the disease, the child recovered rapidly and had a favorable prognosis. KD comorbidities with muscular weakness as the main manifestation are uncommon. This is the first case report of IKD combined with both muscular weakness and bladder and bowel retention, which may provide clinicians with diagnostic and therapeutic ideas, as well as a basis for future exploration of the mechanisms of KD combined with muscular weakness or bladder and bowel retention abnormalities.

Multisystem inflammatory syndrome in children associated with COVID-19: from pathophysiology to clinical management and outcomes

Multisystem inflammatory syndrome in children (MIS-C), also known as pediatric inflammatory multisystem syndrome (PIMS), is a new postinfectious illness associated with COVID-19, affecting children after SARS-CoV-2 exposure. The hallmarks of this disorder are hyperinflammation and multisystem involvement, with gastrointestinal, cardiac, mucocutaneous, and hematologic disturbances seen most commonly. Cardiovascular involvement includes cardiogenic shock, ventricular dysfunction, coronary artery abnormalities, and myocarditis. Now entering the fourth year of the pandemic, clinicians have gained some familiarity with the clinical presentation, initial diagnosis, cardiac evaluation, and treatment of MIS-C. This has led to an updated definition from the Centers for Disease Control and Prevention in the USA driven by increased experience and clinical expertise. Furthermore, the available evidence established expert consensus treatment recommendations supporting a combination of immunoglobulin and steroids. However, the pathophysiology of the disorder and answers to what causes this remain under investigation. Fortunately, long-term outcomes continue to look promising, although continued follow-up is still needed. Recently, COVID-19 mRNA vaccination is reported to be associated with reduced risk of MIS-C, while further studies are warranted to understand the impact of COVID-19 vaccines on MIS-C. We review the findings and current literature on MIS-C, including pathophysiology, clinical features, evaluation, management, and medium- to long-term follow-up outcomes.

Kawasaki Disease in the Time of COVID-19 and MIS-C: The International Kawasaki Disease Registry

BACKGROUND

Patients with multisystem inflammatory syndrome in children (MIS-C) and Kawasaki disease (KD) have overlapping clinical features. We compared demographics, clinical presentation, management, and outcomes of patients according to evidence of previous SARS-CoV-2 infection.

METHODS

The International Kawasaki Disease Registry (IKDR) enrolled KD and MIS-C patients from sites in North, Central, and South America, Europe, Asia, and the Middle East. Evidence of previous infection was defined as: Positive (household contact or positive polymerase chain reaction [PCR]/serology), Possible (suggestive clinical features of MIS-C and/or KD with negative PCR or serology but not both), Negative (negative PCR and serology and no known exposure), and Unknown (incomplete testing and no known exposure).

RESULTS

Of 2345 enrolled patients SARS-CoV-2 status was Positive for 1541 (66%) patients, Possible for 89 (4%), Negative for 404 (17%) and Unknown for 311 (13%). Clinical outcomes varied significantly among the groups, with more patients in the Positive/Possible groups presenting with shock, having admission to intensive care, receiving inotropic support, and having longer hospital stays. Regarding cardiac abnormalities, patients in the Positive/Possible groups had a higher prevalence of left ventricular dysfunction, and patients in the Negative and Unknown groups had more severe coronary artery abnormalities.

CONCLUSIONS

There appears to be a spectrum of clinical features from MIS-C to KD with a great deal of heterogeneity, and one primary differentiating factor is evidence for previous acute SARS-CoV-2 infection/exposure. SARS-CoV-2 Positive/Possible patients had more severe presentations and required more intensive management, with a greater likelihood of ventricular dysfunction but less severe coronary artery adverse outcomes, in keeping with MIS-C.

Long-term outcomes and immune profiling in children with multisystem inflammatory syndrome (MIS-C)

BACKGROUND AND AIM

Existing follow-up data after MIS-C is limited.

PURPOSE OF THE STUDY

to investigate the long-term consequences in children who have undergone MIS-C.

METHODS

The retrospective study included 93 children. The identified changes were divided into the following periods: occurred within first 6 months, 1 year, 2 years, and more than 2 years after MIS-C. Besides, 31 children underwent prospective immunophenotyping of peripheral blood and the determination of cytokines during the acute period of the disease and after discharge.

RESULTS

Outpatient monitoring events included pneumonia (9.6%), somatic disorder syndrome (11.8%), visual impairment (7.5%), joint damage (6.6%), weight changes (2.2%), and MIS-C recurrence (2.2%). A study of the cardiovascular system showed a statistically significant decrease in the frequency of the right and left heart dilatation, left ventricular dysfunction, pericarditis, pulmonary arterial hypertension, coronaritis, mitral regurgitation. But at the same time an increase in pulmonary and tricuspid valve regurgitation and arrhythmias compared with the acute period was detected. Most of the changes took place within first year of observation. Immune profiling showed reconstitution of CD3, CD4 T-lymphocytes, NK-cells, maintenance of a high relative value of CD8, reduction of CD19+ B-cells, expression of CD3-HLA-DR+, CD25, CD279, CD95.

CONCLUSIONS

After the history of MIS-C, children in the long-term follow-up had various somatic disorders and disease recurrence. Most patients (64.1%) showed subclinical signs of myocardial involvement within first year of observation. Low expression of CD95 may justify an certain role in the pathogenesis of the disease.

Multisystem inflammatory syndrome in systemic lupus erythematosus patient with COVID-19: Case report and review

Multisystem inflammatory syndrome in adults (MIS-A) is considered a rare and serious complication of coronavirus disease 2019, which more frequently occurs in young, male, and either non-Hispanic black or Hispanic persons. Here we present a Chinese woman aged 50 years with systemic lupus erythematosus diagnosed with MIS-A. She experienced unexpected sudden cardiac and liver injuries and hemodynamic collapse, and her platelet count dropped sharply on hospital day 2. Unfortunately, the patient's condition gradually deteriorated despite maximum support and she died on day 3. We present this rare case to emphasize that MIS-A in autoimmune diseases may be more severe and its management may be more difficult.

Cardiovascular effects of COVID-19 in children

Introduction

Although severe acute respiratory failure is the primary cause of morbidity and mortality in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, this viral infection leads to cardiovascular disease in some individuals. Cardiac effects of the virus include myocarditis, pericarditis, arrhythmias, coronary aneurysms and cardiomyopathy, and can result in cardiogenic shock and multisystem organ failure.

Method

This review summarises cardiac manifesta-tions of SARS-CoV-2 in the paediatric population. We performed a scoping review of cardiovascular disease associated with acute coronavirus disease 2019 (COVID-19) infection, multisystem inflammatory syndrome in children (MIS-C), and mRNA COVID-19 vaccines. Also examined are special considerations for paediatric athletes and return to play following COVID-19 infection.

Results

Children presenting with acute COVID-19 should be screened for cardiac dysfunction and a thorough history should be obtained. Further cardiovascular evaluation should be considered following any signs/symptoms of arrhythmias, low cardiac output, and/or myopericarditis. Patients admitted with severe acute COVID-19 should be monitored with continuous cardiac monitoring. Laboratory testing, as clinically indicated, includes tests for troponin and B-type natriuretic peptide or N-terminal pro-brain natriuretic peptide. Echocardiography with strain evaluation and/or cardiac magnetic resonance imaging should be considered to evaluate diastolic and systolic dysfunction, coronary anatomy, the pericardium and the myocardium. For patients with MIS-C, combination therapy with intravenous immunoglobulin and glucocorticoid therapy is safe and potentially disease altering. Treatment of MIS-C targets the hyperimmune response. Supportive care, including mechanical support, is needed in some cases.

Conclusion

Cardiovascular disease is a striking feature of SARS-CoV-2 infection. Most infants, children and adolescents with COVID-19 cardiac disease fully recover with no lasting cardiac dysfunction. However, long-term studies and further research are needed to assess cardiovascular risk with variants of SARS-CoV-2 and to understand the pathophysiology of cardiac dysfunction with COVID-19.

Roles of Oxidative Injury and Nitric Oxide System Derangements in Kawasaki Disease Pathogenesis: A Systematic Review

Kawasaki disease (KD) is an acute febrile vasculitis that occurs mostly in children younger than five years. KD involves multiple intricately connected inflammatory reactions activated by a cytokine cascade. Despite therapeutic advances, coronary artery damage may develop in some patients, who will be at risk of clinical cardiovascular events and even sudden death. The etiology of KD remains unclear; however, it may involve both genetic and environmental factors leading to aberrant inflammatory responses. Given the young age of onset, prenatal or perinatal exposure may be etiologically relevant. Multisystem inflammatory syndrome in children, a post-infectious hyper-inflammatory disorder associated with severe acute respiratory syndrome coronavirus 2, has features that overlap with those of KD. Available evidence indicates that vascular endothelial dysfunction is a critical step in the sequence of events leading to the development of cardiovascular lesions in KD. Oxidative stress and the dysregulation of the nitric oxide (NO) system contribute to the pathogenesis of inflammatory responses related to this disease. This review provides current evidence and concepts highlighting the adverse effects of oxidative injury and NO system derangements on the initiation and progression of KD and potential therapeutic strategies for cardiovascular pathologies in affected children.

Multisystem Inflammatory Syndrome in an Adult on Hemodialysis with Markedly Elevated Procalcitonin and Ferritin Levels

A 21-year-old man on hemodialysis was hospitalized for coronavirus disease 2019 (COVID-19) pneumonia. After admission, he had a persistent high fever and developed erythema induratum on his extremities. Laboratory tests conducted 25 days after onset showed markedly increased procalcitonin (PCT) levels (>100 ng/mL). The patient developed impaired consciousness and hypotensive shock and required endotracheal intubation. Based on the presence of erythema induratum and multiorgan dysfunction, he was diagnosed with multisystem inflammatory syndrome (MIS). The MIS resolved after treatment with intravenous immunoglobulin and methylprednisolone. This report illustrates that MIS can occur in adults and may be accompanied by high PCT levels.

Short- and mid-term outcomes of multisystem inflammatory syndrome in children: a longitudinal prospective single-center cohort study

Background

Multisystem inflammatory syndrome in children (MIS-c) emerged during the coronavirus disease 2019 pandemic and is associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite the extensively studied clinical manifestation of acute condition, the short- and long-term effects of MIS-c on children's health are unknown.

Methods

This was a prospective longitudinal cohort study. Children aged <18 years who met the Centers for Disease Prevention and Control (CDC) diagnostic criteria and who were admitted to the Children's Clinical University Hospital of Latvia (CCUH) between July 1, 2020, and April 15, 2022, were enrolled in the study. An outpatient follow-up program was initiated in July 2020. All children were evaluated at 2 weeks, 2 months (1-3 months), and 6 months (5-7 months) after discharge. The face-to-face interviews comprised four domains as follows: symptom assessment, physical examination, laboratory testing, and cardiological investigation [including electrocardiogram (ECG) and echocardiography (echo)].

Results

Overall, 21 patients with MIS-c were enrolled. The median age of the study group was 6 years. At the 2-week follow-up, almost half of the patients (N = 10, 47.6%) reported exercise intolerance with provoked tiredness. Laboratory tests showed a considerable increase in blood cell count, with a near doubling of leukocyte and neutrophil counts and a tripling of thrombocyte levels. However, a decline in the levels of inflammatory and organ-specific markers was observed. Cardiological investigation showed significant improvement with gradual resolution of the acute-phase pathological findings. Within 2 months, improvement in exercise capacity was observed with 5-fold and 2-fold reductions in physical intolerance (N = 2, 9.5%) and physical activity-induced fatigue (N = 5, 23.8%), respectively. Normalization of all blood cell lines was observed, and cardiological investigation showed no persistent changes. At the 6-month visit, further improvement in the children's exercise capacity was observed, and both laboratory and cardiological investigation showed no pathological changes.

Conclusions

Most persistent symptoms were reported within the first 2 weeks after the acute phase, with decreased physical activity tolerance and activity-induced fatigue as the main features. A positive trend was observed at each follow-up visit as the spectrum of the children's complaints decreased. Furthermore, rapid normalization of laboratory markers and cardiac abnormalities was observed.