Inflammatory responses in SARS-CoV-2 associated Multisystem Inflammatory Syndrome and Kawasaki Disease in children: An observational study.

Multisystem Inflammatory Syndrome in Children (MIS-C) is a severe inflammatory disease in children related to SARS-CoV-2 with multisystem involvement including marked cardiac dysfunction and clinical symptoms that can resemble Kawasaki Disease (KD). We hypothesized that MIS-C and KD might have commonalities as well as unique inflammatory responses and studied these responses in both diseases. In total, fourteen children with MIS-C (n=8) and KD (n=6) were included in the period of March-June 2020. Clinical and routine blood parameters, cardiac follow-up, SARS-CoV-2-specific antibodies and CD4+ T-cell responses, and cytokine-profiles were determined in both groups. In contrast to KD patients, all MIS-C patients had positive Spike protein-specific CD3+CD4+ T-cell responses. MIS-C and KD patients displayed marked hyper-inflammation with high expression of serum cytokines, including the drug-targetable interleukin (IL)-6 and IFN-γ associated chemokines CXCL9, 10 and 11, which decreased at follow-up. No statistical differences were observed between groups. Clinical outcomes were all favourable without cardiac sequelae at 6 months follow-up. In conclusion, MIS-C and KD-patients both displayed cytokine-associated hyper-inflammation with several high levels of drug-targetable cytokines.

Kawasaki disease and the current SARS-COV-2 pandemic: Rare lessons from a cohort of more than 1000 kawasaki patients in the netherlands

Background and Aim: Kawasaki disease (KD) is a paediatric vasculitis with an unknown aetiology. The aim of this study was to assess the clinical course, treatment and cardiovascular outcomes in children with KD. The secondary purpose of this study was to make a com-parison with the Kawasaki-like disease Multisystem Inflammatory Syndrome in Children (MIS-C), which is triggered by SARS-CoV-2. Method(s): In this observational cohort study, clinical information from KD and MIS-C patients was collected. Data were described and a multivariate analysis was performed to identify risk factors for coronary artery aneurysms (CAAs). Clinical characteristics between KD and MIS-C were compared using chi-squared and Mann-Whitney U tests. Result(s): 1003 KD patients were included. The male-to-female ratio was 3:2, a majority of the patients were lt;5 years old (78.3%), treated with a single dose of intravenous immunoglobulin (IVIG) (90.8%) and treated promptly (lt;10 days) (81.7%). A second dose of IVIG was needed in minority of the patients (24.7%). The main complication of KD were CAAs and known risk factors (i.e., male, young age, delayed treatment) for CAAs were confirmed. A total of 35 MIS-C patients were included for the comparison. These patients were older than the KD patients (Plt;0.0005), more often had an incomplete KD presentation (Plt;0.0005). MIS-C patients mainly presented with acute cardiac dysfunction, with complete recovery after treatment. Conclusion(s): KD and MIS-C are severe post-infectious inflamma-tory diseases. Due to the risk of cardiovascular complications, vigi-lance and prompt treatment are advised to reduce risk of cardiovascular complications.