POS1251 ROLE OF SYSTEMIC AUTOINMUNE CONDITIONS IN HOSPITAL ADMISSIONS RELATED TO COVID-19
Authors: I. Perez-Sancristobal, L. Lopez Pedraza, M. P. Álvarez Hernandez, J. I. Colomer, A. Madrid García, B. Fernandez, C. Martinez Prada, L. Rodriguez Rodriguez, A. Mucientes, L. León, L. Abasolo
Journal: Annals of the Rheumatic Diseases (2021)

Background: The COVID-19 pandemic continues worldwide and has had a strong impact on public health, quality of life and economy of the general population. To date, the number of infections and deaths are still increasing. From the beginning of the pandemic, efforts were intensified to identify risk factors for development of the severe form of COVID-19. In this sense underlying medical comorbidities have been shown to have a worse prognosis in these patients. Objectives: In patients with rheumatic and musculoskeletal diseases (RMDs) and infected with Covid – 19, we aim to investigate the role of systemic autoimmune conditions compared to other type of RMDs in severity of COVID-19 in terms of hospital admissions. Methods: An observational longitudinal study was conducted during the epidemic peak in Madrid (1 st Mar to 20 th May2020). All patients attended at the rheumatology outpatient clinic of a tertiary hospital with a diagnosis of RMDs and Covid-19 infection were included (according to a medical diagnosis or confirmed with a positive SARS-CoV-2 PCR diagnostic test). All patients were included since the time of COVID-19 diagnosis. Main variable: hospital admission related to Covid -19 infection. Independent variable: type of RMD including: autoimmune (systemic autoimmune conditions and inflammatory joint disease (IJD)) and nonautoimmune (mechanical diseases, and inflammatory diseases (microcrystalline arthritis and tendonitis)). Covariates: sociodemographic, clinical and therapy used. Statistical analysis: description of the sociodemographic, clinical and treatment characteristics of the patients. A multivariate logistic regression adjusted by age, sex and comorbidities was used to evaluate the risk of the different types of RMDs in hospital admissions related to Covid-19. The results were expressed as OR with its corresponding confidence interval (95% CI). Results: 406 patients were included with RMDs and Covid- 19 infection. 69.21% were women with a mean age at diagnosis of 60 ± 15.26 years. The evolution time from the diagnosis of RMD was 8 ± 8.38 years. 26% had comorbidity at baseline. 25% were chronically on corticoids prior to the infection. Of the 406 patients, 244 (60.09%) had non-autoimmune RMD (157 mechanic, 87 inflammatory) and 162 (39.9%) (106 (65.43%) IJD, 56 (34.56%) systemic autoimmune condition) had autoimmune RMD. 36% of all patients were admitted (31% from not autoimmune RMDs and 43% from autoimmune RMD (p = 0,013). The risk of hospital admission in autoimmune RMD compared to non-autoimmune RMD was higher (OR: 1.68; [1.11-2.54], p=0.013), being the risk of systemic autoimmune condition compared to both IJD and non-autoimmune RMD higher (OR IJD: 0.41 [0.21-0.51], p=0.01; OR non-autoimmune: 0.33; [0.18-0.61]; p=0.000). After adjusting by confounders, autoimmune RMD had higher risk of hospital admissions compared to the rest (OR: 1.75; [1.04-2.95]; p=0.03), and specifically systemic autoimmune condition had higher risk compared to IJD (OR of IJD 0.33; [0.14-.076]; p=0.009) and compared to non–autoimmune (OR non autoimmune 0.28; [0.13-0.59], p=0.001). Advanced age (OR: 1.10; [1.07-1.12], p&lt;0.001), male (OR 0.58; [0.33-1.02], p=0.06), and more number of comorbidities (OR 1.39; [1.02-1.90] p=0.03) also increased the risk of hospitalization related to COVID-19. Conclusion: One third of the RMD patients infected with COVID-19 required hospital admission. This study shows that patients with autoimmune and specifically with systemic autoimmune conditions have a higher risk of hospitalization related to COVID-19. We also show that advanced age, male sex and a higher number of comorbidities can contribute to worsen the prognosis of the COVID-19 disease. References: [1]Jorge A, et al. Temporal trends in severe COVID-19 outcomes in patients with rheumatic disease: a cohort study. Lancet Rheumatol . Ahead of print 2021. [2]Hyrich KL, Machado PM. Rheumatic disease and COVID-19: epidemiology and outcomes. Nature Reviews Rheumatology 2020; 17: 71–72. [3]Bonfá E, et al. How COVID-19 is changing rheumatology clinical practice. Nat Rev Rheumatol 2021; 17: 11–15. Disclosure of Interests: None declared