COVID-19, Epstein-Barr virus reactivation and autoimmunity: Casual or causal liaisons?

The coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus infection, has been associated with a substantial risk of autoimmune disease development or exacerbation. The postulated pathophysiological mechanisms linking COVID-19 with autoimmunity include reactivation of latent Epstein-Barr virus (EBV), whose dysregulated infection in the host can trigger or promote an autoimmune response. This review summarizes recent studies highlighting a potential immunopathogenetic link between SARS-CoV2 infection and EBV reactivation, which could underlie autoimmunity onset or worsening, as well as immunerelated long COVID manifestations in COVID-19 patients. We offer our perspective on the direction that research should take to disentangle the nature (whether causal or casual) of the "COVID-19-EBV-autoimmunity" liaisons. Further advances in this research area may be crucial for designing strategies to prevent or treat EBV reactivation-related autoimmune conditions in COVID-19 patients, or patients with inflammatory co-infectious diseases, at the same time promising to improve our knowledge on the viral contribution to autoimmune phenomena.