Clinical and laboratory characteristics of SARS-CoV-2-related multisystem inflammatory syndrome in children
Authors:   Central Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Moscow, Russian Federation, Shalbarova T.V. , Sabinina T.S. ,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, Melekhina E.V. ,   Central Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Moscow, Russian Federation,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, Muzyka А.D. ,   Central Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Moscow, Russian Federation, Novikov D.V. ,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, Barykin V.I. ,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, Sugyan N.G. ,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, Kremplevskaya S.P. ,   Central Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Moscow, Russian Federation,   Khimki Regional Hospital, Khimki, Moscow region, Russian Federation, A.V.Gorelov A.V. ,   I.M.Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russian Federation,   Central Research Institute of Epidemiology, Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing, Moscow, Russian Federation
Published: March 2022

Objective. To analyze clinical manifestations, laboratory parameters, and findings of instrumental examination in children with SARS-CoV-2-related multisystem inflammatory syndrome (MIS). Patients and methods. This study included 60 children aged 1 to 18 years (mean age 8 years) diagnosed with MIS and treated in Khimki Regional Hospital between 06.2020 and 10.2021. All patients underwent standard examination. Results. The majority of MIS patients (87%) were treated in the intensive care unit (ICU) due to severity of their condition; 71% of them were transferred to ICU directly from the admission department. None of children received antiviral therapy upon first encounter with the virus. The proportion of patients with type A blood (group II) was 1.5 times higher than that in the general population. Nine children (15%) were overweight and 5 children (8.3%) were obese. Almost two-thirds of participants (64%) had 3 and 4 systems of organs simultaneously involved in the pathological process. Most commonly, the disease affected the gastrointestinal tract (88%), skin and mucous membranes (77%), cardiovascular system (77%), and urinary tract (43%). Children with MIS were characterized by moderate neutrophilic leukocytosis with a left shift, lymphopenia, thrombocytopenia, anemia, elevated CRP (up to 66x of the upper limit), elevated ferritin (up to 23x of the upper limit), elevated D-dimer, and prolonged aPTT. Conclusion. SARS-CoV-2-related MIS is one of the most severe manifestations of COVID-19 in children, and requires a differential diagnosis with bacterial infections. Key words: children, SARS-CoV-2 infection, multisystem inflammatory syndrome, risk factors