Épidémiologie de l'atteinte dermatologique dans le syndrome de Sjögren : données provenant de trois populations françaises de Syndrome de Sjogren primitif (TEARS, ASSESS, diapSS)

• L'atteinte cutanée est habituelle dans le syndrome de Sjögren primitif (SSp), mais la prévalence et les caractéristiques sont difficiles à établir. • L'atteinte cutanée la plus courante du SSp est la sécheresse cutanée (évaluée par l'EVA). • D'autres signes dermatologiques du SSp sont rares, mais sont associés à l'activité de l'ESSDAI dans d'autres domaines. Déterminer la prévalence et les caractéristiques de l'atteinte dermatologique dans le syndrome de Sjögren primitif (SSp). Nous avons utilisé 2 cohortes françaises de SSp (ASSESS, qui a évalué la prévalence des atteintes cutanées chez 395 patients atteints de SSp ;et diapSS, dans laquelle 76 sur 139 patients atteints de SSp ont été examinés par un dermatologue) et les données de base de l'essai randomisé TEARS (110 patients atteints de SSp récents ou actifs traités avec du rituximab ou un placebo et évalués pour la sécheresse de la peau à l'aide d'une échelle visuelle analogique (EVA) sur 100). Les manifestations cutanées incluses dans l'indice d'activité EULAR du syndrome de Sjögren (ESSDAI) étaient rares dans la cohorte ASSESS (n = 16/395, 4,1 %, principalement des purpuras ;seuls 3 avaient une activité élevée), mais elles étaient associées à une activité dans les autres domaines de l'ESSDAI (système neurologique périphérique (p < 0,001), musculaire (p < 0,01), hématologique (p < 0,05), biologique (p < 0,05), antécédents d'arthrite (p < 0,01), splénomégalie (p < 0,05) et taux de gammaglobulines plus élevés (p < 0,01)). Dans la cohorte diapSS, comparés aux patients SSp ne recevant pas de consultation dermatologique, les patients SSp qui ont eu une consultation dermatologique avaient significativement plus d'atteintes dermatologiques en dehors du score ESSDAI (38,2 % (29/76) contre 15,9 % (10/63) ;p < 0,01). L'étude TEARS a montré une forte prévalence de la sécheresse cutanée (EVA≥50 ;48, 2 %) et a constaté que les patients ayant la peau sèche présentaient des scores EVA de douleur et de sécheresse globale plus élevés (p < 0,01 et p < 0,001 respectivement). Les signes dermatologiques inclus dans le score ESSDAI sont rares. Ces atteintes cutanées sont associées à l'activité de l'ESSDAI dans divers domaines notamment à l'hypergammaglobulinémie et à l'activité globale de l'ESSDAI. L'examen dermatologique systématique est instructif pour les lésions cutanées non-spécifiques. L'atteinte cutanée la plus fréquente est la sécheresse cutanée, qui est associée à une douleur plus forte et à une sécheresse subjective globale plus importante. [ FROM AUTHOR] Copyright of Revue du Rhumatisme is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Lymphocyte Changes in Severe COVID-19: Delayed Over-Activation of STING?

Upon recognition of microbial DNA or self-DNA, the cyclic-GMP-AMP synthase (cGAS) of the host catalyzes the production of the cyclic dinucleotide cGAMP. cGAMP is the main activator of STING, stimulator of interferon genes, leading to interferon synthesis through the STING-TBK1-IRF3 pathway. STING is also a hub for activation of NF-κB and autophagy. The present review details the striking similarities between T and B cell responses in severe coronavirus disease 2019 (COVID-19) and both animal or human models of STING gain of function (SAVI syndromes: STING-associated vasculopathy with onset in infancy). Those similarities may be further clues for a delayed activation of STING in severe COVID-19 patients, due to DNA damages following severe acute respiratory syndrome coronaviruses (SARS-CoV-2) infection and unusual role of STING in SARS-CoV-2 control. In early stages, Th2 differentiation are noticed in both severe COVID-19 and SAVI syndromes; then, CD4+ and CD8+ T cells functional exhaustion/senescent patterns due to TCR hyper-responsiveness are observed. T cell delayed over-responses can contribute to pneumonitis and delayed cytokine secretion with over-production of IL-6. Last, STING over-activation induces progressive CD4+ and CD8+ T lymphopenia in SAVI syndromes, which parallels what is observed in severe COVID-19. ACE2, the main receptor of SARS-CoV-2, is rarely expressed in immune cells, and it has not been yet proven that some human lymphocytes could be infected by SARS-CoV-2 through CD147 or CD26. However, STING, expressed in humans T cells, might be triggered following excessive transfer of cGAMP from infected antigen presenting cells into activated CD4+ and CD8+ T cells lymphocytes. Indeed, those lymphocytes highly express the cGAMP importer SLC19A1. Whereas STING is not expressed in human B cells, B cells counts are much less affected, either in COVID-19 or SAVI syndromes. The recognition of delayed STING over-activation in severe COVID-19 patients could prompt to target STING with specific small molecules inhibitors already designed and/or aspirin, which inhibits cGAS.

Kawasaki-like diseases and thrombotic coagulopathy in COVID-19: delayed over-activation of the STING pathway?

We previously made the hypothesis that STING contributes to COVID-19. The present review detail new arguments for over-activation of STING pathways in COVID-19, following the description of hyper-coagulability and Kawasaki-like diseases in children. Indeed, Kawasaki disease is induced by overreaction of innate cells following exposition to various viruses, including herpes viruses which trigger STING. It predisposes to diffuse vasculitis and aneurysms, whereas STING is over-expressed in arterial aneurisms. The redness at the inoculation site of bacillus Calmette-Guérin, a specific feature of Kawasaki disease, is reproduced by activation of the STING pathway, which is inhibited upstream by aspirin, intravenous immunoglobulins, and Vitamin-D. SARS-CoV2 binding to ACE2 can lead to excessive angiotensin II signaling, which activates the STING pathway in mice. Over-activation of the STING-pathway promotes hyper-coagulability through release of interferon-ß and tissue factor by monocytes-macrophages. Aspirin and dipyridamole, besides their anti-platelet activity, also reduce tissue factor procoagulant activity, and aspirin inhibits the STING pathway upstream of STING. Aspirin and dipyridamole may be used, in combination with drugs blocking downstream the activation of the STING pathway, like inhibitors of IL-6R and JAK/STAT pathways. The risk of bleeding should be low as bleeding has not been reported in severe COVID-19 patients.