Association between EBV serological patterns and lymphocytic profile of SjS patients support a virally triggered autoimmune epithelitis

Immune and non-immune mediators in the fibrosis pathogenesis of salivary gland in Sjögren's syndrome

Sjögren's syndrome (SS) or Sjögren's disease (SjD) is a systemic autoimmune disease clinically manifested as sicca symptoms. This disease primarily impacts the functionality of exocrine glands, specifically the lacrimal and salivary glands (SG). SG fibrosis, an irreversible morphological change, is a severe consequence that occurs in the later stages of the disease due to sustained inflammation. However, the mechanism underlying SG fibrosis in SS remains under-investigated. Glandular fibrosis may arise from chronic sialadenitis, in which the interactions between infiltrating lymphocytes and epithelial cells potentially contributes to fibrotic pathogenesis. Thus, both immune and non-immune cells are closely involved in this process, while their interplays are not fully understood. The molecular mechanism of tissue fibrosis is partly associated with an imbalance of immune responses, in which the transforming growth factor-beta (TGF-β)-dependent epithelial-mesenchymal transition (EMT) and extracellular matrix remodeling are recently investigated. In addition, viral infection has been implicated in the pathogenesis of SS. Viral-specific innate immune response could exacerbate the autoimmune progression, resulting in overt inflammation in SG. Notably, post-COVID patients exhibit typical SS symptoms and severe inflammatory sialadenitis, which are positively correlated with SG damage. In this review, we discuss the immune and non-immune risk factors in SG fibrosis and summarize the evidence to understand the mechanisms upon autoimmune progression in SS.

The role of Epstein-Barr virus in autoimmune and autoinflammatory diseases

Epstein-Barr Virus (EBV), a dsDNA herpesvirus, is believed to play a significant role in exacerbating and potentially triggering autoimmune and autoinflammatory maladies. Around 90% of the world is infected with the virus, which establishes latency within lymphocytes. EBV is also known to cause infectious mononucleosis, a self-limited flu-like illness, in adolescents. EBV is often reactivated and it employs several mechanisms of evading the host immune system. It has also been implicated in inducing host immune dysfunction potentially resulting in exacerbation or triggering of inflammatory processes. EBV has therefore been linked to a number of autoimmune diseases, including systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren's syndrome. The review examines the molecular mechanisms through which the virus alters host immune system components thus possibly resulting in autoimmune processes. Understanding the mechanisms underpinning EBV-associated autoimmunity is pivotal; however, the precise causal pathways remain elusive. Research on therapeutic agents and vaccines for EBV has been stagnant for a long number of years until recent advances shed light on potential therapeutic targets. The implications of EBV in autoimmunity underscore the importance of developing targeted therapeutic strategies and, potentially, vaccines to mitigate the autoimmune burden associated with this ubiquitous virus.

The seven-fold rise in incidence of Stevens-Johnson syndrome & toxic epidermal necrolysis: Associations with COVID-19 and the vaccine

Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is a rare, potentially life threatening mucocutaneous hypersensitivity reaction resulting in desquamation of the skin and mucosa. These patients are managed on burns units due to the widespread desquamation. We report the largest case series of participants developing SJS/TEN in the setting of recent COVID infection or vaccination. We found a seven-fold increase in SJS/TEN since the COVID pandemic. This increase correlates with an increase in COVID infections and vaccination rates. We explore the immunopathological relationships between COVID and SJS/TEN and propose theories for possible associations.

Herpesviridae, Neurodegenerative Disorders and Autoimmune Diseases: What Is the Relationship between Them?

Alzheimer's disease and Parkinson's disease represent the most common forms of cognitive impairment. Multiple sclerosis is a chronic inflammatory disease of the central nervous system responsible for severe disability. An aberrant immune response is the cause of myelin destruction that covers axons in the brain, spinal cord, and optic nerves. Systemic lupus erythematosus is an autoimmune disease characterized by alteration of B cell activation, while Sjögren's syndrome is a heterogeneous autoimmune disease characterized by altered immune responses. The etiology of all these diseases is very complex, including an interrelationship between genetic factors, principally immune associated genes, and environmental factors such as infectious agents. However, neurodegenerative and autoimmune diseases share proinflammatory signatures and a perturbation of adaptive immunity that might be influenced by herpesviruses. Therefore, they might play a critical role in the disease pathogenesis. The aim of this review was to summarize the principal findings that link herpesviruses to both neurodegenerative and autoimmune diseases; moreover, briefly underlining the potential therapeutic approach of virus vaccination and antivirals.

Virus-Derived Small RNAs and microRNAs in Health and Disease

MicroRNAs (miRNAs) are short noncoding RNAs that can regulate all steps of gene expression (induction, transcription, and translation). Several virus families, primarily double-stranded DNA viruses, encode small RNAs (sRNAs), including miRNAs. These virus-derived miRNAs (v-miRNAs) help the virus evade the host's innate and adaptive immune system and maintain an environment of chronic latent infection. In this review, the functions of the sRNA-mediated virus-host interactions are highlighted, delineating their implication in chronic stress, inflammation, immunopathology, and disease. We provide insights into the latest viral RNA-based research-in silico approaches for functional characterization of v-miRNAs and other RNA types. The latest research can assist toward the identification of therapeutic targets to combat viral infections.

Chronic Epstein-Barr virus infection: A potential junction between primary Sjögren's syndrome and lymphoma

Primary Sjögren's syndrome (pSS) is an autoimmune disease that targets exocrine glands, leading to exocrine dysfunction. Due to its propensity to infect epithelial and B cells, Epstein-Barr virus (EBV) is hypothesized to be related with pSS. Through molecular mimicry, the synthesis of specific antigens, and the release of inflammatory cytokines, EBV contributes to the development of pSS. Lymphoma is the most lethal outcome of EBV infection and the development of pSS. As a population-wide virus, EBV has had a significant role in the development of lymphoma in people with pSS. In the review, we will discuss the possible causes of the disease.

EBV dUTPase: A Novel Modulator of Inflammation and the Tumor Microenvironment in EBV-Associated Malignancies

There is increasing evidence that put into question the classical dogma that the Epstein-Barr virus (EBV) exists in cells as either a lytic virus in which new progeny is produced or in a latent state in which no progeny is produced. Notably, a third state has now been described, known as the abortive-lytic phase, which is characterized by the expression of some immediate early (IE) and early (E) genes, but no new virus progeny is produced. While the function of these IE and E gene products is not well understood, several recent studies support the concept they may contribute to tumor promotion by altering the tumor microenvironment (TME). The mechanisms by which these viral gene products may contribute to tumorigenesis remain unclear; however, it has been proposed that some of them promote cellular growth, immune evasion, and/or inhibit apoptosis. One of these EBV early gene products is the deoxyuridine triphosphate nucleotidohydrolase (dUTPase) encoded by BLLF3, which not only contributes to the establishment of latency through the production of activin A and IL-21, but it may also alter the TME, thus promoting oncogenesis.

Hospitalizations for infections in primary Sjögren's syndrome patients: a nationwide incidence study

BACKGROUND

Primary Sjögren's syndrome (pSS) is an autoimmune disease with increased risk of infections. Here, we assessed whether pSS patients were at higher risk of hospitalization for community and opportunistic infections.

METHODS

We selected newly hospitalized pSS patients between 2011 and 2018, through a nationwide population-based retrospective study using the French Health insurance database. We compared the incidence of hospitalization for several types of infections (according to International Classification for Disease codes, ICD-10) between pSS patients and an age- and sex-matched (1:10) hospitalized control group. We calculated adjusted Hazard Ratios (aHR, 95% CI) adjusted on socio-economic status, past cardiovascular or lung diseases and blood malignancies factors.

RESULTS

We compared 25 661 pSS patients with 252 543 matched patients. The incidence of hospitalizations for a first community infection was increased in pSS patients [aHR of 1.29 (1.22-1.31), p < .001]. The incidence of hospitalization for bronchopulmonary infections was increased in pSS patients [aHR of 1.50 (1.34-1.69), p < .001, for pneumonia]. Hospitalizations for pyelonephritis and intestinal infections were increased [aHR of 1.55 (1.29-1.87), p < .001 and 1.18 (1.08-1.29), p < .001, respectively]. Among opportunistic infections, only zoster, and mycobacteria infections (tuberculosis and non-tuberculous) were at increased risk of hospitalization [aHR of 3.32 (1.78-6.18), p < .001; 4.35 (1.41-13.5), p = .011 and 2.54 (1.27-5.06), p = .008, respectively].

CONCLUSIONS

pSS patients are at higher risk of hospitalization for infections. The increased risk of hospitalization for mycobacterial infections illustrates the potential bilateral relationship between the two conditions. Vaccination against respiratory pathogens and herpes zoster virus may help prevent some hospitalizations in pSS patients.KEY MESSAGESPrimary Sjögren's syndrome (pSS) increases hospitalization risk for community infections: bronchopulmonary, skin, dental, ear-nose-throat, intestinal infections and pyelonephritis.Hospitalizations for zoster and mycobacterial infections are also increased in this population.Dedicated preventive measures and vaccination campaigns could decrease the burden of infections in pSS patients.