Background: The study of the features of the course and mutual influence of the new coronavirus disease COVID-19 and various rheumatic diseases (RD) in children can still give us new lessons, warnings and fears.

Objectives: To update the analysis in a retrospective study the course of covid-19 in children with RD based on the results of two years of the pandemic. To analyze the impact of COVID-19 on the course of RD in children.

Methods: Retrospective analysis based on data from single center. The study included patients with RD and confirmed COVID-19 for 2 years (2020-2021).

Results: Were registered 320 cases of COVID-19 in children with RD. 158 (49%) patients were asymptomatically infected, 162 (51%) had clinical symptoms. A detailed description of the groups is presented in Table 1 . Clinical symptoms were fever (67%), anosmia (47%), rhinitis (34%), cough (19%), arthralgia/myalgia (16%), dyspepsia (5%), rash (2.5%), pneumonia (3%). In the majority of cases (98%), COVID-19 proceeded in mild to moderate severity. Hospitalization due to COVID-19 was required just in 5 cases. 2 children were admitted to the intensive care unit. First, an 11-year-old girl with sJIA with the history of recurrent episodes of MAS resolved by regular administration of canakinumab. 2 ^nd , a 12-year-old girl with Sjogren’s syndrome, who received Rituximab and 1 month later she developed the COVID-19 with MIS-like clinical picture, pneumonia with 25%CT lessions. Both cases have a favorable outcome.

The clinical characteristics of the patients are presented in Table 1 . COVID-19 didn`t affect the course of RD in the 86% of pts. However, 15% developed a flare of the RD with average of 3 months after COVID-19. In this group for 13 pts (girls mostly F/M-9/4, mean age 15 years [9;16]), COVID-19 triggered the new onset of RD (non-systemic JIA – 4, Uveitis – 1, non-bacterial osteomyelitis – 3, systemic JIA – 2, Scleroderma – 2, Sjögren’s syndrome – 1. 12 from 13 these children had clinical symptoms on COVID-19. Whether this is Long-COVID syndrome or an independent RD is not known.

Conclusion: Our study suggests that the new coronavirus infection in most cases in children with RD, had mild or asymptomatic course, regardless of therapy with immunosuppressive drugs and bDMARD, except of 1 observation with the previous therapy of Rituximab. Worsening of RD after coronavirus infection developed in 15% of cases, regardless of its clinical manifestations. In 13 patients, the RD were started just after COVID-19. The explosive increasing of the incidence of a new strain of COVID-19 for a past month may change the current results and conclusions.

Disclosure of Interests: None declared