AB0023 A SINGLE CENTER STUDY ON THE EFFECTS OF SARS-CoV-2 INFECTION AND VACCINATION IN PATIENTS WITH ADULT-ONSET STILL’S DISEASE

Background: Adult-onset Still's disease (AOSD) is a rare, autoinflammatory disease characterized by fever, arthralgia or arthritis, sore throat, salmon-colored rash, hyperferritinemia, abnormal liver enzymes, and neutrophilic leukocytosis. Though the exact etiology is unknown, it is theorized that the disease develops in genetically predisposed individuals after exposure to environmental triggers such as infections. Given the recent SARS-CoV-2 virus outbreak, the large-scale vaccination effort, and recent case reports of AOSD onset after SARS-CoV-2 infection, we designed the following study. Objectives: The aim of this study is to investigate the effects of SARS-CoV-2 infection and vaccination in patients with AOSD. Methods: In this study, patients with AOSD in follow-up at the Rheumatology Unit of the Azienda Ospedaliero-Universitaria IRCCS in Bologna (Italy) that had undergone at least one SARS-CoV-2 vaccination between January 2021 and January 2023 were enrolled. Data regarding number of vaccination doses, SARS-CoV-2 infections, disease flares, and treatments were collected. Results: In total twenty patients (7 female, 13 male) with AOSD were enrolled in the study. The median age was 53.35 years, ranging from 20-81 years of age. Of the twenty patients, only 10 reported a SARS-CoV-2 infection and none of the cases were serious, requiring hospital admission. One of these ten patients was treated with a specific antiviral therapy. The median number of doses received of the SARS-CoV-2 vaccine were 3.1. In one patient, the onset of AOSD was 7 days after a paucisymptomatic SARS-CoV-2 infection. The AOSD treatment of our cohort is summarized in Table 1. Only two patients had AOSD flares during the study. One patient, in drug-free remission, 7 days after the SARS-CoV-2 vaccination (3rd dose) with concomitant gastroenteritis had a mild flare successfully treated with oral corticosteroids. The second patient, also in drug-free remission, had an AOSD flare nearly 3 weeks after a SARS-CoV-2 vaccination (1st dose) and was treated with oral corticosteroids. The patient later underwent the 2nd and 3rd doses without additional flares. Conclusion: This study underlines the importance of SARS-CoV-2 vaccination in patients with AOSD that prevented serious infection (requiring hospital admission) in all cases, despite the number of patients in treatment with drugs affecting the immune system. Additionally, only 2 patients had mild flares after vaccination and, in both cases, possible confounding factors can be identified (concomitant gastroenteritis and time between possible trigger and flare). It is of note that one patient had AOSD onset after a SARS-CoV-2 infection, highlighting its possible etiologic role. Additional research with larger cohorts is needed to further investigate this correlation. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.