Programmed Cell Death Protein-1 Regulation in Response to SARS-CoV-2 in Paediatric Multisystem Inflammatory Syndrome Temporally Associated with SARS-CoV-2: A Prospective Cohort Study.

The role of programmed death cell protein 1 (PD-1) has already been described in a range of various diseases, including COVID-19. This study provides new, innovative data, related to the expression of PD-1 and the risk of Paediatric Inflammatory Multisystem Syndrome, temporally associated with SARS-CoV-2 infection (PIMS-TS)-a rare, but potentially life-threatening complication of COVID-19. In this study, we evaluated the expression of PD-1 protein in patients with PIMS. Blood samples were taken from patients at the time of diagnosis (n = 33), after 6 weeks (n = 33), 3 months (n = 24), 6 months (n = 24) and 12 months (n = 8). The immunophenotypes were evaluated in flow cytometry. The control group consisted of 35 healthy children with negative SARS-CoV-2 antigen/PCR test, who were asymptomatic and had no history of allergic, autoimmune or oncological diseases. The associations between immunophenotypes, biochemical findings and clinical data were analysed. Significant increases in the expression of PD-1 for CD4+ and CD8+ T cells, compared to the control group, were observed in the day of admission, with a gradual decrease during the first weeks from initiation of treatment. This study sheds new light on the pathogenesis of PIMS-TS, emphasizing the role of PD-1 protein. Future research is essential for early risk prediction in SARS-CoV-2 patients and for devising effective clinical prevention and management strategies.

Anti-SARS-CoV-2 Vaccination and PIMS-TS-Friends or Foe? Case Reports and Literature Review.

Pediatric inflammatory, multisystem syndrome temporally associated with SARS-CoV-2 infection (PIMS-TS), also known as a multisystem inflammatory syndrome in children (MIS-C), is diagnosed in children who develop an inadequate inflammatory response after exposure to the SARS-CoV-2 virus. The pathogenesis of the abnormal response of the immune system to a previous SARS-COV-2 infection has not been explained. Similarly, the safety and effectiveness of COVID-19 vaccinations in this group of patients have become the subject of clinical discussion. Presenting experiences from many centers aims to answer this question. We present 4 cases of patients who suffered from PIMS-TS. Three of them were safely vaccinated against COVID-19 after illness. One patient developed PIMS-TS temporarily associated with COVID-19 vaccination. We also collected and discussed data from other centers.

Safety of the COVID-19 vaccination in children with juvenile idiopathic arthritis-A observational study from two pediatric rheumatology centres in Poland.

Introduction: The safety of COVID-19 vaccines in children with juvenile idiopathic arthritis (JIA) is the concern of patients and their parents and doctors in the current pandemic reality. The main objective of the study was to evaluate the safety of COVID-19 vaccine in patients with JIA. Method: A cohort study based on short clinical follow-up of 43 children with JIA was conducted in the years 2021-2022 in two centres of paediatric rheumatology in Poland. All patients received mRNA COVID-19 vaccine. The patients' data were collected using appropriate validated questionnaire. Disease activity was evaluated using Juvenile Arthritis Disease Activity Score 27-joint count (JADAS-27). Results: Ten (22.7%) children had COVID-19 infection before getting COVID-19 vaccine. After first dose of COVID-19 vaccine 25/43 (58.1%) patients presented typical adverse events: arm pain or oedema at the application side or weakness. Also, twenty five (58.1%) children had side effects after second dose of this vaccine, however the spectrum of the symptoms was wider (additionally: headache, fever, lymphadenopathy, arrhythmia). Thirteen out of 43 (30.2%) patients had active disease before and 8/43 (18.6%) after COVID-19 vaccination, while the degree of JADAS-27 activity was higher in the study group before COVID-19 vaccination (p = 0.047). Conclusions: Our study found out that children and adolescents with JIA with remission without treatment or on the long-term treatment-cDMARDs or even bDMARDs, can be safely vaccinated for COVID-19. Moreover, the study found that COVID-19 vaccination does not interfere with the JIA treatment and does not exacerbate symptoms of the disease and that vaccination protected against developing COVID-19 in children with JIA even on treatment.