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Updated: Dec 22, 2025

Live Imaging and Quantification of Viral Infection in K18 hACE2 Transgenic Mice Using Reporter-Expressing Recombinant SARS-CoV-2
Published on: November 5, 2021
SARS-CoV-2 infection among patients with systemic autoimmune diseases
Giacomo Emmi1, Alessandra Bettiol2, Irene Mattioli1
1Department of Experimental and Clinical Medicine, University of Firenze, Italy.
Objectives:
This study aimed to evaluate the prevalence of clinically overt SARS-CoV-2 infection (COVID-19) among patients with systemic autoimmune diseases residing in Tuscany, and to compare it with that observed in the general Tuscan population.
Methods:
In this cross-sectional study, Tuscan outpatients with systemic autoimmune diseases followed at a tertiary referral centre were telephonically interviewed between April 1st-14th 2020 to collect demographic and clinical data, information on ongoing immunomodulating/immunosuppressive treatments, and on the presence of symptoms suspected of SARS-CoV-2 or of a confirmed infection.
Results:
458 patients were interviewed [74% female, median age 56 years (IQR 43-68)]; 56% of them were receiving corticosteroids, 44% traditional disease-modifying anti-rheumatic drugs (DMARDs), of whom 23% hydroxychloroquine, 5% colchicine, while 41% were on biologic DMARDs (of whom 9% on tocilizumab). Thirteen patients reported symptoms suggesting SARS-CoV-2 infection. Of them, 7 had undergone nasopharyngeal swab and only one was positive and developed severe SARS-CoV-2 complications. Within our cohort, the prevalence of SARS-CoV-2 infection was therefore 0.22% (0.01-1.21%), comparable to that observed in the general population of Tuscany [0.20% (0.20-0.21%), p = .597].
Conclusions:
Patients with systemic autoimmune diseases do not seem to carry an increased risk of SARS- CoV-2 infection as compared to the general population.
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