Severity of COVID-19 infection in primary Sjögren's syndrome and the emerging evidence of COVID-19-induced xerostomia.

Abstract

Since the beginning of the COVID-19 disease pandemic caused by the new coronavirus SARS-CoV-2, the disease has claimed over 205M cases (205,338,159) and 4,333,094 deaths (WHO dashboard - accessed 15/08/2021). In addition to the overwhelming impact on healthcare systems treating acutely ill patients, the pandemic has had an impact on all other aspects of health care delivery, including the management of chronic diseases, the risk that is posed in patients with chronic conditions and the risk of the infection itself in those with chronic conditions. Autoimmune rheumatic diseases (ARDs), including primary Sjögren's syndrome (pSS), characterised by immune dysregulation affecting several organs in variable severity, have been of particular interest given the accelerated phase of the immune response in the course of SARS-CoV-2 infection leading to the acute inflammatory response and respiratory distress syndrome or multi-organ failure. On the other hand, the effect of immunosuppressive drug therapies can represent a double edge sword on the course of the disease, either by increased susceptibility to and severity of the infection, or by preventing the accelerated inflammatory response induced by the infection. Additionally, the long-term impact of SARS-CoV-2 infection on the host immune system has led to the onset of novel complex clinical manifestations, comprised under the large umbrella of "long-COVID", which we are only starting to understand. In this review we focus on two interrelated aspects: i) the impact of COVID-19 on patients with pSS and ii) the emerging evidence of long-term xerostomia after SARS-CoV-2 infection.