Study characterizes immunological features of SARS-CoV-2 infection in children

A recent study conducted by a team of Italian scientists found that the clinical severity of coronavirus disease 2019 (COVID-19) in children was induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. demonstrated to depend on the dynamics of the immune response. .

This research is currently research plaza* Preprint server considering publishing on scientific report.

Background

SARS-CoV-2, the causative agent of COVID-19, has caused less severe infections in children and adolescents throughout the pandemic. However, clinical severity may also be observed in some cases, such as pediatric systemic polyinflammatory syndrome (MIS-C). This condition is characterized by an abnormal inflammatory response.

The reasons behind the observed differences in clinical severity between children and adults are not fully understood. However, patterns of social interaction viral loadand age-related immune response dynamics make children less susceptible to SARS-CoV-2 infection.

In the current study, scientists evaluated the correlation between immune responses induced by SARS-CoV-2 and COVID-19 severity in children. In a subset of children with severe infection, we characterize immune response dynamics with cardiovascular manifestations.

Study population

This study included a total of 18 children hospitalized with SARS-CoV-2 infection. The immunological profile of infected children was compared with that of 13 healthy children (controls).

Patients were classified based on clinical severity and age. Moderate and severe infections were found in his 56% and his 44% of patients. Her average length of stay was 12 days, and her only child was admitted to the intensive care unit (ICU).

Patients with moderate infections had upper or lower respiratory tract infections without organ dysfunction. In contrast, severely infected patients experienced multiple organ failure or required supplemental oxygen. Cardiovascular involvement was documented in 7 children.

Dynamics of antibody responses in children infected with SARS-CoV-2

binding and Neutralizing antibody Virus against SARS-CoV-2 was detected in 78% of patients.

In addition to clinical severity, age-related differences in antibody responses in hospitalized children were assessed. Based on age, they were classified as infants, children, and adolescents.

Significantly higher levels of anti-spike receptor binding domain (RBD) IgG antibodies were detected in severely infected children than in moderately infected children. Significantly higher levels of anti-RBD IgM antibodies were detected in moderately infected adolescents than in heavily infected infants. Regarding neutralizing antibodies, significantly higher values ​​were detected in severely ill children than in severely ill children.

Dynamics of inflammatory response

Patients with severe infection had significantly higher levels of circulating cytokines and chemokines compared with those with moderate infection. The highest levels of cytokines and chemokines were detected in infants with severe infections.

A comparison of inflammatory and antibody responses revealed a negative correlation between antibody and cytokine/chemokine levels in infants and children with severe infections and cardiovascular disease. In particular, anti-SARS-CoV-2 binding antibodies negatively correlated with interleukin-2 (IL-2).

A strong correlation was observed between selected cytokines and chemokines among infants, children and adolescents with moderate infections. Considering virus-specific binding antibodies, a negative correlation with IL-12 levels was observed.

Only weak correlations between antibodies and inflammatory responses were observed in children and adolescents with moderate infection and very low cytokine/chemokine levels. Virus-specific binding antibodies negatively correlated with IL-8, IL-5, and monocyte chemoattractant protein-1. Notably, the circulating cytokine/chemokine profiles of these patients significantly overlapped with those of healthy children.

Compared with healthy children, SARS-CoV-2-infected children had significantly increased production of SARS-CoV-2-stimulated cytokines and chemokines, leading to T lymphocyte activation and migration-specific proteins. It was observed that the levels of

Significance of research

This study provides an overview of antibody and inflammatory responses in hospitalized infants, children and adolescents with moderate or severe SARS-CoV-2 infection. Overall, this study reveals that the dynamics of virus-induced immune responses are directly correlated with disease severity and partially correlated with age.

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