Cardiac MRI in midterm follow-up of MISC: a multicenter study.

In this multicenter retrospective study we aimed to evaluate the outcome of cardiac involvement in children affected by multisystem inflammatory syndrome (MIS-C), assessed through cardiac magnetic resonance (CMR). Children referring to three Italian tertiary pediatric centers between February 2020 and November 2021 with a diagnosis of MIS-C, who underwent CMR during a follow-up visit, were enrolled. Demographic, clinical, laboratory, treatment, and outcome data were collected. Twenty MIS-C patients (aged 9-17, median 12 years) were included in the study. Heart involvement at onset was testified by hypotension/shock (55%), laboratory evidence of myocardial involvement (100%), reduced LV ejection fraction (EF) on echocardiography (83%), and/or need for inotrope agents (40%); they all presented good clinical, laboratory, and echocardiographic response to treatment. CMR was performed after a median interval of 3 months from discharge. Pericardial effusion and myocardial edema were found in 5% of patients. Mild residual left ventricular (LV) dysfunction was found in 20% of patients, all showing normal echocardiographic LVEF at discharge. Minimal myocardial scars were found in 25% by late gadolinium enhancement (LGE). One patient was evaluated at two consecutive time points, showing partial resolution of a myocardial scar after 7 months from its first finding. CONCLUSION: Despite the severity of heart involvement in the acute MIS-C phase, the mid-term cardiac outcome is good. Direct cardiac tissue viral invasion may be involved in MIS-C pathogenesis. WHAT IS KNOWN: • Heart involvement is common in MIS-C, but conflicting findings have been shown regarding cardiac outcome when assessed through cardiac MRI. WHAT IS NEW: • Midterm cardiac MRI shows mild abnormalities in patients recovered from MIS-C with any grade of severity of cardiac involvement at presentation.

Evolution of SARS-CoV-2 IgG Seroprevalence in Children and Factors Associated with Seroconversion: Results from a Multiple Time-Points Study in Friuli-Venezia Giulia Region, Italy.

Data on the effective burden of the SARS-CoV-2 pandemic in the pediatric population are limited. We aimed at assessing the prevalence of SARS-CoV-2 IgG antibodies in children at three subsequent time-points. The study was conducted between January 2021 and July 2021 among children referring to the Research Institute for Maternal and Child Health "Burlo Garofolo" in Trieste, a referral regional hospital in Friuli Venezia Giulia, Italy. A multivariate analysis was conducted to assess factors independently associated with seroconversion. A total of 594 children were included. Anti-SARS-CoV-2 trimeric Spike protein IgG antibodies were found in 32 (15.4%) children tested in April-May and in 20 (11.8%) in June-July 2021, compared with 24 (11.1%) of those tested in January-February 2021 (p = 0.37, Armitage exact test for trend over time p = 0.76). A subgroup analysis and a multivariate logistic regression analysis were performed considering sociodemographic, clinical, and historical variables. Three categories of children showed statistically significant increased odds of positive anti-SARS-CoV-2 IgG antibodies: children previously positive to a nasopharyngeal swab (AdjOR 15.41, 95%CI 3.44-69.04, p < 0.001), cohabitant with a person with an history of a previous positive nasopharyngeal swab (AdjOR 9.95, 95%CI 5.35-18.52, p < 0.001), and children with a foreign citizenship (AdjOR 2.4, 95%CI 1.05-5.70, p = 0.002). The study suggests that seroprevalence studies may be of limited help in estimating the prevalence of the COVID-19 pandemic in children. Further studies are needed to identify other markers of previous SARS-CoV-2 infection in children, such as CD4+ T cells or memory B-cells.

Prevalence of SARS-CoV-2 infection in Italian pediatric population: a regional seroepidemiological study.

BACKGROUND: Data on the effective burden of the SARS-CoV-2 pandemic in pediatric population are very limited, mostly because of the higher rate of asymptomatic or paucisymptomatic cases among children. Updated data on COVID-19 prevalence are needed for their relevance in public health and for infection control policies. In this single-centre cross-sectional study we aimed to assess prevalence of SARS-CoV-2 infection through IgG antibodies detection in an Italian pediatric cohort. METHODS: The study was conducted in January 2021 among both inpatients and outpatients referring to Research Institute for Maternal and Child Health "Burlo Garofolo" in Trieste, Friuli Venezia-Giulia, Italy, who needed for blood test for any reason. Collected samples were sent to Italian National Institute of Health for analysis through chemiluminescent immunoassay (CLIA). RESULTS: One hundred sixty-nine patients were included in the study, with a median age of 10.5 ± 4.1 years, an equal distribution for sex (49.7% female patients), and a 55.6% prevalence of comorbidities. Prevalence of anti-SARS-CoV-2 trimeric Spike protein IgG antibodies was 9.5% (n = 16), with a medium titre of 482.3 ± 387.1 BAU/mL. Having an infected cohabitant strongly correlated with IgG positivity (OR 23.83, 95% CI 7.19-78.98, p < 0.0001), while a cohabitant healthcare worker wasn't associated with a higher risk (OR 1.53, 95% CI 0.4-5.86, p 0.46). All of the 5 patients who had previously tested positive to a nasopharyngeal swab belonged to the IgG positive group, with a 3-month interval from the infection at most. CONCLUSION: We assessed a 9.5% SARS-CoV-2 seroprevalence in a pediatric cohort from Friuli Venezia-Giulia region in January 2021, showing a substantial increase after the second peak of the pandemic occurred starting from October 2020, compared to 1% prevalence observed by National Institute of Statistics (ISTAT) in July 2020.