Editorial: Chronic autoimmune arthritis, infections and vaccines

The link between autoimmunity and infection continues to represent an intriguing immunologic conundrum for scientist and a frequent clinical challenge for patients and physicians. Patients with chronic autoimmune arthritis indeed have an increased risk of infections, mainly due to the dysregulation of their immune system and the use of immunosuppressive therapy. Infections in these patients are more frequent, have a more severe clinical course, eventually with prolonged viral persistence, compared to the general population and represent a frequent cause of death. Besides, infections can trigger autoimmune diseases via different immunologic mechanisms such as molecular mimicry, epitope spreading, by-stander activation and can also induce disease relapses. SARS-CoV-2 infection represents a dramatic example of this complex connection. It is known, indeed, that different autoimmune manifestations can complicate SARS-CoV-2 infection such as uncontrolled host-immune response leading to life-threatening condition known as cytokine release syndrome, or autoimmune hemolytic anemia, immune thrombocytopenic purpura, Guillain-Barre syndrome, and the detection of different autoantibodies. This Research Topic includes seventeen contributions, fifteen original articles and two review articles, providing several new insights into the efficacy and safety of SARS-CoV-2 vaccine in autoimmune patients, immunologic biomarkers for diagnosis and therapeutic outcome of autoimmune arthritis.