P. Duffau

Role of extracellular vesicles in autoimmune diseases

Extracellular vesicles (EVs) consist of exosomes released upon fusion of multivesicular bodies with the cell plasma membrane and microparticles shed directly from the cell membrane of many cell types. EVs can mediate cell-cell communication and are involved in many processes including inflammation, immune signaling, angiogenesis, stress response, senescence, proliferation, and cell differentiation. Accumulating evidence reveals that EVs act in the establishment, maintenance and modulation of autoimmune processes among several others involved in cancer and cardiovascular complications. EVs could also present biomedical applications, as disease biomarkers and therapeutic targets or agents for drug delivery.

Oral erosive lichen planus and Good's syndrome: just a coincidence or a direct link between the two diseases?

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IgE Inhibits Toll-like Receptor 7- and Toll-like Receptor 9-Mediated Expression of Interferon-α by Plasmacytoid Dendritic Cells in Patients With Systemic Lupus Erythematosus.

Plasmacytoid dendritic cells (PDCs) play a central role in pathogenesis of systemic lupus erythematosus (SLE) through their unique ability to produce large amounts of type I interferon (IFN) upon Toll‐like receptor 7 (TLR‐7) and TLR‐9 triggering. PDCs express specific surface regulatory receptors involved in negative regulation of IFNα secretion. These receptors use the γ‐chain of high‐affinity Fc receptor (FcR) for IgE, FcɛRI. We undertook this study to test our hypothesis that IgE engagement of FcɛRI on PDCs may impact IFNα production in SLE patients.

Efficacy and safety of autologous haematopoietic stem cell transplantation in systemic sclerosis: A systematic review of literature

We aimed to assess the efficacy of autologous haematopoietic stem cell transplantation (HSCT) for skin sclerosis (SSc) and lung function in SSc. We performed a systematic literature review in the PubMed and Scopus databases from the earliest records to March 2016. We assessed study quality using the Cochrane tool for randomized studies, the Newcastle–Ottawa Scale for controlled cohort studies and an 18‐item quality‐appraisal checklist for case series. The primary outcome was the improvement of skin thickening using the modified Rodnan Skin Score (mRSS). The secondary outcome was efficacy on lung function, using diffusing capacity of the lungs for carbon monoxide and forced vital capacity (FVC). The safety of the procedure was evaluated. The literature search identified 431 citations. There were 38 studies involving a total of 344 patients who fulfilled our inclusion criteria. No meta‐analysis was performed due to a high heterogeneity. There was a significant improvement in mRSS in the majority of the reports (P < 0·05), and the results were sustained for up to 8 years after autologous HSCT. The randomized studies and the four cohort studies each showed a slight but statistically significant improvement in FVC at 1 or 2 years. The treatment‐related mortality calculated by pooling patients of 35 studies (336 patients with a follow‐up up to 146 months) was 8·3% after autologous HSCT and 1% in cyclophosphamide‐treated groups. Despite heterogeneity among the studies, we determined that autologous HSCT significantly improved cutaneous fibrosis and slightly improved FVC. Safety of autologous HSCT is acceptable given the severity of the disease. This systematic review was registered on PROSPERO, number CRD42016027951.

New Insights on Platelets and Platelet-Derived Microparticles in Systemic Lupus Erythematosus

Purpose of reviewCurrent knowledge on the role of platelets and platelet-derived microparticles (PMPs) on the immune system has been fast-growing. Systemic lupus erythematosus (SLE) is a systemic auto-immune disorder characterized by a loss of tolerance toward nuclear auto-antigens. Although recent studies allowed a better understanding of SLE pathogenesis, there is an urgent need for the development of new treatments and the identification of new biomarkers to assess the disease activity. We describe here the state-of-the-art knowledge linking platelets and PMPs to SLE.Recent findingsPlatelet system activation is a key event in the pathogenesis of SLE. Circulating immune complexes, anti-phospholipid antibodies, and infectious agents such as virus are the main activators of platelets in SLE. Platelet activation can be monitored through different ways such as P-selectin expression, mean platelet volume, or circulating PMP levels, suggesting their potential use as biomarkers. Upon activation, platelets promote type I interferon production, NETosis, dendritic cell activation, and T and B lymphocyte activation, all essential events contributing to the development of SLE. Of interest, platelets also play a fundamental role in SLE organ disease such as the development of cardiovascular, thrombotic, and renal diseases. Finally, we review current knowledge on drugs targeting platelet activation and their potential impact on SLE pathogenesis.SummaryPlatelets play a major role in SLE pathogenesis and organ disease and represent a great potential for novel biomarkers and drug development.

IgE inhibits TLR‐7 and ‐9 mediated expression of interferon‐alpha by plasmacytoid dendritic cells in systemic lupus patients

Plasmacytoid dendritic cells (PDCs) play a central role in pathogenesis of systemic lupus erythematosus (SLE) through their unique ability to produce large amounts of type I interferon (IFN) upon Toll‐like receptor 7 (TLR‐7) and TLR‐9 triggering. PDCs express specific surface regulatory receptors involved in negative regulation of IFNα secretion. These receptors use the γ‐chain of high‐affinity Fc receptor (FcR) for IgE, FcɛRI. We undertook this study to test our hypothesis that IgE engagement of FcɛRI on PDCs may impact IFNα production in SLE patients.

Predictive biological markers of systemic lupus erythematosus flares: a systematic literature review

BackgroundThe aim of this study was to identify the most reliable biomarkers in the literature that could be used as flare predictors in systemic lupus erythematosus (SLE).MethodsA systematic review of the literature was performed using two databases (MEDLINE and EMBASE) through April 2015 and congress abstracts from the American College of Rheumatology and the European League Against Rheumatism were reviewed from 2010 to 2014. Two independent reviewers screened titles and abstracts and analysed selected papers in detail, using a specific questionnaire. Reports addressing the relationships between one or more defined biological test(s) and the occurrence of disease exacerbation were included in the systematic review.ResultsFrom all of the databases, 4668 records were retrieved, of which 69 studies or congress abstracts were selected for the systematic review. The performance of seven types of biomarkers performed routinely in clinical practice and nine types of novel biological markers was evaluated. Despite some encouraging results for anti-double-stranded DNA antibodies, anti-C1q antibodies, B-lymphocyte stimulator and tumour necrosis factor-like weak inducer of apoptosis, none of the biomarkers stood out from the others as a potential gold standard for flare prediction. The results were heterogeneous, and a lack of standardized data prevented us from identifying a powerful biomarker.ConclusionsNo powerful conclusions could be drawn from this systematic review due to a lack of standardized data. Efforts should be undertaken to optimize future research on potential SLE biomarkers to develop validated candidates. Thus, we propose a standardized pattern for future studies.

Systemic lupus erythematosus and systemic sclerosis: All roads lead to platelets

Systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) are two phenotypically distincts inflammatory systemic diseases. However, SLE and SSc share pathogenic features such as interferon signature, loss of tolerance against self-nuclear antigens and increased tissue damage such as fibrosis. Recently, platelets have emerged as a major actor in immunity including auto-immune diseases. Both SLE and SSc are characterized by strong platelet system activation, which is likely to be both the witness and culprit in their pathogenesis. Platelet activation pathways are multiple and sometimes redundant. They include immune complexes, Toll-like receptors activation, antiphospholipid antibodies and ischemia-reperfusion associated with Raynaud phenomenon. Once activated, platelet promote immune dysregulation by priming interferon production by immune cells, providing CD40L supporting B lymphocyte functions and providing a source of autoantigens. Platelets are actively implicated in SLE and SSc end-organ damage such as cardiovascular and renal disease and in the promotion of tissue fibrosis. Finally, after understanding the main pathogenic implications of platelet activation in both diseases, we discuss potential therapeutics targeting platelets.

Management and outcomes of 27 pregnancies in women with myeloproliferative neoplasms

Abstract Introduction: Philadelphia-negative myeloproliferative neoplasms (MPNs) greatly increase the risk of maternal and fetal complications during pregnancy. Currently, international agreements regarding the management of these women are lacking. Patients and methods: Our study aimed to assess the current management and outcomes of MPN pregnancies in a French cohort. We retrospectively analyzed 27 pregnancies in women with MPNs that were associated with a specific mutation. Nineteen pregnancies in nine women with essential thrombocythemia and eight pregnancies in five women with polycythemia vera were identified. Results: Our study showed 70% live births, but only 30% uneventful pregnancies. Fetal complications were mainly early spontaneous abortions (22%), fetal growth restriction (15%), and premature delivery (15%). Maternal issues were divided between thrombosis (15%) and hemorrhages (11%). High rates of preeclampsia and hemolysis, elevated liver enzymes, and low platelet count syndrome (15%) were reported. Uterine artery Doppler was performed in 70% pregnancies. Abnormal Doppler results were found in 43% pregnancies. Pregnancies with high platelet counts and packed cell volume remaining static or increasing ended with fetal death and utero-placental dysfunction. According to expert consensus, most of the pregnancies (67%) could be stratified in the high risk group and had a bad obstetrical outcome, with 50% standard-risk pregnancies versus 22% high-risk pregnancies that were uneventful. Higher risk pregnancies were prescribed heparin and/or interferon α in 72%. Conclusions: The prognosis of these pregnancies remains very bad and may be improved by a more effective collaboration between specialists as well as a therapeutic intensification including heparin and interferon α.

Neutrophil-derived mitochondrial DNA promotes receptor activator of nuclear factor κB and its ligand signalling in rheumatoid arthritis

ObjectivesnMitochondrial DNA (mtDNA) contains sequestered damage-associated molecular patterns that might be involved in osteoimmunological pathogenesis of RA. Here, we aimed to investigate the cellular source of mtDNA and its role in RANK ligand (RANKL) expression by RA SF neutrophils.nnnMethodsnThe gene expression signature of SF neutrophils was examined by proteomic quantitative analysis. Levels of mtDNA in circulating and SF neutrophils from RA patients and OA control subjects were assessed by real-time PCR. Purified neutrophils were challenged in vitro with Toll-like receptor agonists as well as mtDNA. RANKL expression by neutrophils was studied by flow cytometry.nnnResultsnSF neutrophils from RA patients displayed a gene expression signature of oxidative stress. This stress signature was associated with the release of mtDNA in SF as observed by a significant increase of mtDNA in the SF of RA patients compared with OA patients. mtDNA in RA SF was correlated with systemic inflammation as assessed by CRP concentrations. We also showed that mtDNA drives neutrophil RANKL expression to the same extent as Toll-like receptor agonists.nnnConclusionnOur data identify SF neutrophils as a cellular source of mtDNA that leads to a subsequent expression of RANKL. This highlights the important role of neutrophils in RA osteoimmunology.