Prevalence and clinical course of SARS-CoV-2 infection in patients with Behçet's syndrome.

We aimed to assess the prevalence of SARS-CoV-2 infection among Behçet's syndrome (BS) patients, evaluating the possible association between demographic and clinical features and the risk of infection. Moreover, we aimed to evaluate the possible association between BS disease activity and treatment, and the risk of SARS-CoV-2 infection. A survey was conducted on BS patients followed at the Behçet's Centre of the Careggi University Hospital, Florence, Italy. We further evaluated the possible association between BS disease activity and treatment, and the risk of SARS-CoV-2 infection. Out of 335 BS patients contacted, fourteen cases of SARS-CoV-2 were identified between April 1st, 2020 and February 9th, 2021, suggesting a prevalence of SARS-CoV-2 infection among BS patients of 4.2%, in line with the data of the general population in Italy (4.4%). When comparing clinical features between SARS-CoV-2 cases and matched SARS-CoV-2 negative BS patients, we found that the presence of different disease manifestations did not significantly differ between the two groups. SARS-CoV-2 cases and controls were also comparable in terms of immunosuppressive therapy, with the only exception of corticosteroids (71.4% vs. 35.7%, p=0.030), whose daily dose was significantly higher in cases than controls [5mg/day (IQR 0-10,) vs. 0 mg/day (IQR 0-5), p=0.005], suggesting that the right timing of usage and the more appropriate dosage of corticosteroid are a key question for the better management of these patients. Based on our results, patients with BS do not seem to be at a greater risk of SARS-CoV-2 infection or severe complications compared with the general population.