ABSTRACT
Background: A novel viral infection known as COVID-19 (Coronavirus-19 disease) spread up in Wuhan (China) in December 2019, but rapidly diffused worldwide and nowadays it remains an international health problem. Because of its impact on immunologic system, immunomodulating therapies have been studied as possible treatments for severe cases of COVID-19. In that context, patients affected by from rheumatic musculoskeletal disorders (RMD) under disease modifying anti-rheumatic drugs (DMARDs) have been observed in several studies to evaluate the impact of COVID-19 on these subjects, well known to be at higher risk of infection. Objectives: The primary objective of this study is to assess prevalence and severity of COVID-19 in patients with RMD under treatment with biologic (b-DMARDs) or targeted synthetic (ts-DMARDs) DMARDs, before the vaccination campaign. The second aim is to compare those data with that in general population of the same Area (Province of Udine, Friuli Venezia Giulia Region, Italy,). Methods: A cohort of RMD patients treated with b-DMARDs or ts-DMARDs was observed from September 2019 to November 2020. Both pandemic waves have been considered, until the start of vaccination (since current variants can overcome vaccine protection), between February 2020 and April 2020 (first wave) and between September 2020 and November 2020 (second one). Results: Among 1051 RMD patients treated with b-or ts-DMARDs COVID-19 prevalence was 3.5% (37 cases) without significant differences compared to general population of the same Region (Table 1). Infected patients were 18 men and 19 women, with a median age of 60 years (IQR 49-68). Notably, the infection rate of RMD patients was significantly lower compared to the general population of the same province, particularly during the second wave (p<0.001, Table 1). Almost all patients reported fever (70%). Gastro-intestinal symptoms (nausea, vomit and diarrhoea) have been recorded in 10 subjects (27%) and resulted significantly associated with longer swab pos-itivity (p<0.05) (Figure 1). Only a small percentage of patients with COVID-19 infection was receiving corticosteroids (8%), and the doses were low (3.5 or 5 mg per day of prednisone equivalents). The most used b-DMARDs were anti-TNFs (24/37, 65%), while just 4/37 (11%) employed JAK inhibitors. A small percentage of patients (6/37, 16%) continued ongoing treatment, with no worsened outcomes, while none preventively suspended the immuno-suppressant. The course of infection was generally benign with a mortality rate of 2.6% (1 patient, with several risk factors) and only 9 patients needed to be hospitalized (24%). After COVID-19 infection, 12 subjects (32%) had RMD flare and 5 of them subsequently needed to change the immunosup-pressive drug. Conclusion: The prevalence of COVID-19 in RMD patients has been confrmed low in both waves and it could be partially explained by the great awareness about preventive strategies by the patients. The benign course of COVID-19 in our patients may be linked to the very low amount of chronic corticosteroids used and the possible protective effect of anti-TNF agents, which were the main class of biologics herein employed. Gastro-intestinal symptoms might be a predictor of viral persistence in immunosuppressed patients. This fnding could be useful to identify earlier COVID-19 carriers with uncommon symptoms (without respiratory manifestations), eventually eligible for antiviral drugs.