COVID-19 Heart Lesions in Children: Clinical, Diagnostic and Immunological Changes

Abstract

In the beginning of COVID-19, the proportion of confirmed cases in the pediatric population was relatively small and there was an opinion that children often had a mild or asymptomatic course of infection. Our understanding of the immune response, diagnosis and treatment of COVID-19 is highly oriented towards the adult population. At the same time, despite the fact that COVID-19 in children usually occurs in a mild form, there is an incomplete understanding of the course as an acute infection and its subsequent manifestations such as Long-COVID-19 or Post-COVID-19, PASC in the pediatric population, correlations with comorbidities and immunological changes. In mild COVID-19 in childhood, some authors explain the absence of population decreasing T and B lymphocytes. Regardless of the patient’s condition, they can have the second phase, related to the exacerbation of inflammation in the heart tissue even if the viral infection was completely eliminated—post infectious myocarditis. Mechanism of myocardial dysfunction development in MIS-C are not fully understood. It is known that various immunocompetent cells, including both resident inflammatory cells of peripheral tissues (for example macrophages, dendritic cells, resident memory T-lymphocytes and so on) and also circulating in the peripheral blood immune cells play an important role in the immunopathogenesis of myocarditis. It is expected that hyperproduction of interferons and the enhanced cytokine response of T cells 1 and 2 types contribute to dysfunction of the myocardium. However, the role of Th1 in the pathogenesis of myocarditis remains highly controversial. At the same time, the clinical manifestations and mechanisms of damage, including the heart, both against the background and after COVID-19, in children differ from adults. Further studies are needed to evaluate whether transient or persistent cardiac complications are associated with long-term adverse cardiac events.

Severe Course of COVID-19 and Long-COVID-19 in Children: Difficulties in Diagnosis

“…The issue of differential diagnosis of MIS-C with other pathological conditions, including other infectious diseases that occur with similar clinical and laboratory symptoms, is extremely relevant [ 36 , 37 ].…”

“…Perhaps, in the future, specialists will have to deal with new variants of the course of MIS-C and the consequences of COVID-19 in pediatric practice. Currnently, knowledge on the pathogenesis, diagnosis, treatment, and prevention of long-COVID-19 in children is still lacking [ 37 ]. Clinical symptoms and the involvement of various organs and systems, including cardiovascular, in long-COVID-19 in the pediatric population requires study in order to understand these issues better.…”

SARS-CoV-2 Infection in Venezuelan Pediatric Patients: A Single Center Prospective Observational Study

“…Differences in circulating lymphocyte populations and cytokine levels were observed in patients similarly treated with steroids as reported [33][34]. Increased levels of IL-10 and a decreased amount of CD4 were recorded.…”

Reply to: Letter on the Recent Paper “Vascular ‘Long COVID’: A New Vessel Disease?”

“…Among 320 825 people with Long-COVID-19 Syndrome in the UK, .16% of cases were in children aged 2-11 years, .65% in children aged 2-16 years and 1.22% in those aged 17-24 years. 3,4 This is one of the reasons why it is quite difficult to predict which children will develop Long-COVID-19. Furthermore, in the vast majority of Long-COVID-19 studies, symptoms were reported by parents.…”

“…Furthermore, in the vast majority of Long-COVID-19 studies, symptoms were reported by parents. 3,4 The symptoms of Long Covid Syndrome in children are very varied and include headaches, fatigue, skin rashes, nonspecific respiratory symptoms, and gastrointestinal symptoms. This constellation of symptoms makes early diagnosis even more difficult.…”