ABSTRACT
Background: Autoimmune diagnosis plays an important role in the diagnosis, classification and prognosis of systemic autoimmune rheumatic diseases (SARD). The coronavirus disease 2019 (COVID-19) pandemic has a profound impact on clinical and diagnostic practices on a global scale. In the current study we aimed to provide reliable data on the effects of COVID-19 pandemic on autoimmunity testing requests, rate of positivity and rheumatological clinical practices. Methods: Data on autoimmunity test numbers, positive results, first rheumatological visits and new diagnosis have been collected from medical records and laboratory information system for the COVID-19 pandemic phase (January-December 2020) and compared with those obtained during the corresponding period in 2019. The list of autoantibodies included: anti-nuclear antibody, anti-extractable nuclear antigens, anti-dsDNA, rheumatoid factor, anti-citrullinated protein-peptide antibodies and antineutrophil cytoplasmic antibodies (anti-myeloperoxidase and anti-serine proteinase 3). Results: A statistically significant reduction of all laboratory parameters investigated were found during the pandemic period (9912 vs. 14,100 for all patients, P<0.05;1547 vs. 2276 for selected outpatients only, P<0.05). A significant reduction in first rheumatological visits and new diagnosis was also observed with an absolute difference between study periods equal to 1064 rheumatological visits (1272 vs. 2336, P<0.05) meaning a total visits decreasing of 48%. The decline was more sustained during the first wave of the pandemic and less pronounced during the second wave. However, an equivalent or higher percentage of positive test results from outpatients were recorded during 2020 when compared to prepandemic state and the decline in new diagnosis mainly affected less severe diseases. In contrast, SARD with systemic involvement were diagnosed without significant differences. Conclusions: Our data showed a greater appropriateness of autoantibodies request and rheumatological visits during the COVID-19 pandemic compared to prepandemic period, as demonstrated by a higher percentage of positive results and new diagnosis of more severe SARD.