ABSTRACT
Resume. In first two years of COVID-19 pandemic, children usually had a mild or asymptomatic form of the disease. However, in rare cases, after suffering COVID-19, children had clinical manifestations similar to incomplete Kawasaki Disease (CD) or toxic shock syndrome. This condition is known as multisystem inflammatory syndrome in children (MIS-C). The purpose of this research was to study clinical and laboratory features and outcomes of multisystem inflammatory syndrome in children who were hospitalized during COVID-19 pandemic. Materials and methods. In 19 months (May 2020 - December 2021) 63 patients with a diagnosis of Multisystem inflammatory syndrome in children (MIS-C) associated with COVID-19 were observed in the departments of Anesthesiology and Intensive Care of the Healthcare Institution "City Children's Infectious Clinical Hospital" in Minsk, Republic of Belarus. MIS-C was diagnosed on criteria of CDC/WHO, 2020. All calculations were carried out in the statistical package R, version 4.1. The results of the analysis were considered statistically significant with p<0,05. The results of the study. All of 63 children with MIS-C didnt have an acute coronavirus infection. Therefore, it was impossible to determine which strain of SARS-CoV-2 patient exactly had. However, we formed 3 groups of patients based on circulation of the dominant strain of SARS-CoV-2 in Belarus at different times. The 1st group included 40 patients (63,5%) received treatment from 05.25.2020 to 02.21.2021 ("wuhan strains"); the 2nd group - 9 children (14,3%) from 02.23.2021 to 06.13.2021 ("alpha"); the 3rd group - 14 children (22,2%) from 07.01.2021 to 11.19.2021 ("delta"). 47 (74,6%) patients had complete and incomplete Kawasaki Disease phenotype of MIS-C. Nonspecific phenotype was observed in 16 (25,4%) children. It manifested as signs of shock. The mean age didnt differ in study groups. All children had hyperthermic syndrome. Fever reached febrile numbers 3-4 times a day. Average fever duration was 3,2 [1-15] days. The course of MIS-C in children also didnt depend on the circulating strain of the virus. For instance, gastrointestinal dysfunction was observed in all three groups with equal frequency (73%, 78% and 57%, respectively). The only a statistically significant increase was in the number of children with cheilitis. In the 2nd group 8 children (89%) and the 3rd group 13 children (93%) had cheilitis, respectively, p=0,002. Neurological disorders such as headache, hyperesthesia, hallucinations, photophobia were more often observed in the 1st group of children - 19 (48%) cases and less frequently in the 2nd and 3rd group (in 11% and 14% of cases), p=0,022. Pathological blood flow regurgitation was the most common disorder (68-71%). Several biochemical markers of inflammation levels, such as C-reactive protein (CRP) and procalcitonin (PCT), were high. CRP levels were 162 mg/l [130; 245]; 130 mg/l [90; 160]; 130 mg/l [106; 149] in 3 study groups, respectively. In children of the 1st group CRP level was significantly higher, p=0.052. PCT level was higher in patients of the 3rd group (4.2 ng/ml [2,4; 8,8]; 3.9 ng/ml [3,2; 11,9]; 8.7 ng/ml [3,4; 14,1], p=0.625). Conclusion. As a result of the research there wasnt found notable connection between clinical or laboratory features of MIS-C and the dominant circulating strain of SARS-CoV-2 in given time periods. During the circulation of "alpha" and "delta" strains, the only significant differences were decrease of the number of patients with neurological disorders and increase in the frequency of cheilitis, p=0,002. The remaining indicators of organ dysfunction were similar in three groups of children. There was 1 (1,6%) fatal outcome in our study.