Epidemiology of Sjögren's: A Systematic Literature Review

Modulation of myeloid-derived suppressor cell functions by oral inflammatory diseases and important oral pathogens

The oral cavity presents a diverse microbiota in a dynamic balance with the host. Disruption of the microbial community can promote dysregulation of local immune response which could generate oral diseases. Additionally, alterations in host immune system can result in inflammatory disorders. Different microorganisms have been associated with establishment and progression of the oral diseases. Oral cavity pathogens/diseases can modulate components of the inflammatory response. Myeloid-derived suppressor cells (MDSCs) own immunoregulatory functions and have been involved in different inflammatory conditions such as infectious processes, autoimmune diseases, and cancer. The aim of this review is to provide a comprehensive overview of generation, phenotypes, and biological functions of the MDSCs in oral inflammatory diseases. Also, it is addressed the biological aspects of MDSCs in presence of major oral pathogens. MDSCs have been mainly analyzed in periodontal disease and Sjögren's syndrome and could be involved in the outcome of these diseases. Studies including the participation of MDSCs in other important oral diseases are very scarce. Major oral bacterial and fungal pathogens can modulate expansion, subpopulations, recruitment, metabolism, immunosuppressive activity and osteoclastogenic potential of MDSCs. Moreover, MDSC plasticity is exhibited in presence of oral inflammatory diseases/oral pathogens and appears to be relevant in the disease progression and potentially useful in the searching of possible treatments. Further analyses of MDSCs in oral cavity context could allow to understand the contribution of these cells in the fine-tuned balance between host immune system and microorganism of the oral biofilm, as well as their involvement in the development of oral diseases when this balance is altered.

Estimated prevalence, incidence and healthcare costs of Sjögren's syndrome in France: a national claims-based study

OBJECTIVES

To estimate prevalence, incidence and mortality rates, and annual healthcare costs of primary Sjögren's syndrome (pSS) and SS associated with other autoimmune disorders (SS+AID) in France.

METHODS

French national healthcare claims-based study within the prospective Système National des Données de Santé database that includes the majority of the French population. An algorithm was developed to identify patients with SS and SS-related healthcare claims were analysed between 2011 and 2018.

RESULTS

Overall, 23 848 patients with pSS and 14 809 with SS+AID were identified. From 2011 to 2018, the prevalence rate increased slightly for pSS (23-32 per 100000) and SS+AID (16-20 per 100 000), with females comprising 90%-91% and 92%-93% of cases, respectively. The incidence rate of SS per 100 000 persons decreased from 2012 (pSS: 4.3; SS+AID: 2.0) to 2017 (pSS: 0.7; SS+AID: 0.3). Mortality rates per 100 000 persons increased from 2012 to 2018 in patients with pSS (0.2-0.8) or SS+AID (0.1-0.5); mean age of death also increased. Artificial tears and hydroxychloroquine were the most common drug reimbursements. Less than half of patients received annual specialist care from a dentist or ophthalmologist. Healthcare costs associated with SS increased from 2011 to 2018 and exceeded the national estimate of expected costs for chronic diseases.

CONCLUSION

In this large French population database study, the low prevalence of pSS confirms that it is an orphan disease. SS is clinically and economically burdensome; these findings may help clinicians better understand routine healthcare received by patients.