ABSTRACT
The "Severe Acute Respiratory Syndrome-related Coronavirus type 2” (SARS-CoV-2), the infectious agent responsible for the still ongoing "Coronavirus Disease 2019” (COVID-19) pandemic, represents a major environmental trigger and an important piece of the mosaic of autoimmunity and autoinflammation. Several de novo-onset or flares/relapses of autoimmune/autoinflammatory diseases have been reported associated either directly or indirectly with the viral agent. COVID-19 has represented a unique opportunity for shedding new light and unexpected insights on autoimmune/autoinflammatory diseases. These have, in turn, enabled the discovery of novel aspects of the COVID-19 infection, offering already approved, effective and safe drugs, as options to be repurposed in the fight against the novel coronavirus. However, there is still a dearth of information concerning the long-term impact of the virus on autoimmunity and autoinflammation - the so-called long-COVID or postCOVID, which warrants further investigation. © 2023 Elsevier Inc. All rights reserved.
ABSTRACT
In our continuing examination of the role of exposomes in autoimmune disease, we use this review to focus on pathogens. Infections are major contributors to the pathophysiology of autoimmune diseases through various mechanisms, foremost being molecular mimicry, when the structural similarity between the pathogen and a human tissue antigen leads to autoimmune reactivity and even autoimmune disease. The three best examples of this are oral pathogens, SARS-CoV-2, and the herpesviruses. Oral pathogens reach the gut, disturb the microbiota, increase gut permeability, cause local inflammation, and generate autoantigens, leading to systemic inflammation, multiple autoimmune reactivities, and systemic autoimmunity. The COVID-19 pandemic put the spotlight on SARS-CoV-2, which has been called "the autoimmune virus." We explore in detail the evidence supporting this. We also describe how viruses, in particular herpesviruses, have a role in the induction of many different autoimmune diseases, detailing the various mechanisms involved. Lastly, we discuss the microbiome and the beneficial microbiota that populate it. We look at the role of the gut microbiome in autoimmune disorders, because of its role in regulating the immune system. Dysbiosis of the microbiota in the gut microbiome can lead to multiple autoimmune disorders. We conclude that understanding the precise roles and relationships shared by all these factors that comprise the exposome and identifying early events and root causes of these disorders can help us to develop more targeted therapeutic protocols for the management of this worldwide epidemic of autoimmunity.