Case report: Exploring under the tip of the iceberg: A case series of "self-limiting" multisystem inflammatory syndrome in children.

Multisystem inflammatory syndrome in children (MIS-C) is a serious condition triggered by SARS-COV-2 infection, characterized by persistent fever, multiorgan dysfunction, and increased inflammatory markers. It requires hospitalization and prompt treatment, with nearly 60% of the cases needing intensive care and 2% fatality rate. A wide spectrum of clinical characteristics and therapeutic approaches has been reported in MIS-C. We describe a series of four patients with MIS-C, defined according to the current case definitions, with a self-limiting course and no need for immunomodulatory treatment ("self-limiting MIS-C"). Few data about self-limiting MIS-C are available to date and no information on medium- and long-term outcome of this subset of patients has been reported. Although limited in size, our experience provides new insights into the MIS-C syndrome, highlighting an underestimated aspect of the disease that may have significant therapeutic implications.

Acute and late echocardiographic and cardiac MRI findings in multisystem inflammatory syndrome in children

Aims Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe condition affecting children previously exposed to SARS-CoV-2. The aim of our study was to describe the acute and late cardiac abnormalities in patients with MIS-C, evaluated by speckle-tracking echocardiography (STE) and cardiac MRI (CMR). Methods and results Twenty-three (13 M, 10 F) patients with confirmed MIS-C diagnosis were recruited. All children underwent standard TTE, STE with analysis of LV global longitudinal strain (GLS). Seventeen (75%) were evaluated with CMR. All children received standard therapy. During follow-up echocardiography and CMR were repeated. Mean age was 8.1 ± 4 years. The majority (78.2%) was Caucasian. Cardiovascular symptoms were present in 10 (43.5%). Nine children (39.1%) shared Kawasaki Disease-like symptoms. Four patients (17.4%) needed ICU admission and three required inotropic support. Short-term survival was 100%. All patients showed a hyperinflammatory state. Tn-I was abnormal (>34 ng/l) in 15 patients (65.2%), BNP was elevated in 20 (86.9%). Median time to STE evaluation was 8 days and to CMR 18 days since fever onset. Mean LVEF and RVEF were, respectively, 59 ± 10% and 45 ± 7%. Coronary dilation was observed in six (26.1%) patients. STE showed reduced mean LVGLS (−17 ± 4.3%). LVEF on CMR was 60 ± 13%, LGE with non-ischaemic pattern was evident in 6/17 patients (35.2%). Median time to follow-up was 49 days for echocardiography and 200 days for CMR since disease onset. STE showed improvement of LVGLS (−18.8 ± 2.2%), while CMR displayed persistence of LGE in two patients and reduction or absence in two of the six patients previously diagnosed. Conclusions The elevation of myocardial necrosis markers, the myocardial injury testified by reduced LVGLS and the presence of LGE on CMR in about a quarter of the patients support the hypothesis of a post-viral immune-mediated myocarditis-like pathogenesis of MIS-C. Early follow-up shows improvement of STE and CMR findings corroborating the evidence of excellent short-term survival.

Early Echocardiographic and Cardiac MRI Findings in Multisystem Inflammatory Syndrome in Children.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a known severe condition affecting children previously exposed to SARS-CoV-2. The aim of our study was to describe the early cardiac abnormalities in patients with MIS-C, evaluated by speckle tracking echocardiography (STE) and cardiac MRI (CMR). Clinical, laboratory and microbiological data were measured for all patients. All children underwent standard transthoracic echocardiography, STE with analysis of left ventricle global longitudinal strain (GLS). Seventeen (75%) of the children were evaluated with CMR. Twenty-three patients (13M, 10F) were recruited, mean age was 8.1 ± 4 years. Cardiovascular symptoms were present in 10 (43.5%). Nine children (39.1%) shared Kawasaki Disease-like symptoms. Four patients (17.4%) needed ICU admission. In-hospital survival was 100%. TnI was elevated in 15 (65.2%) and BNP in 20 (86.9%) patients. The median time to STE evaluation was 8 days and to CMR was 18 days after fever onset. Mean LVEF was 59 ± 10%. Coronary dilation was observed in six (26.1%) patients. STE showed a reduced mean LVGLS (-17 ± 4.3%). LGE with a non-ischemic pattern was evident in six out of seventeen patients (35.2%). The elevation of myocardial necrosis markers, the reduction of LVGLS and the presence of LGE on CMR in about a quarter of MIS-C patients supports the hypothesis of a post-viral immune-mediated myocarditis-like pathogenesis.