Protein-bound uremic toxins (PBUTs) accumulate in chronic kidney disease (CKD) and are poorly removed by dialysis. Gryp et al. demonstrated that fecal bacteria from patients with CKD do not produce ...more PBUTs than do those from healthy controls and that the accumulation of PBUTs, as CKD progresses, is mainly due to their reduced renal elimination by glomerular filtration and tubular secretion. This work underlines the importance of studying the metabolism of PBUTs along the diet-gut-liver-kidney axis.
Alterations of renal endothelial cells play a crucial role in the initiation and progression of diabetic kidney disease. High glucose per se, as well as glucose by-products, induce endothelial ...dysfunction in both large vessels and the microvasculature. Toxic glucose by-products include advanced glycation end products (AGEs), a group of modified proteins and/or lipids that become glycated after exposure to sugars, and glucose metabolites produced via the polyol pathway. These glucose-related endothelio-toxins notably induce an alteration of the glomerular filtration barrier by increasing the permeability of glomerular endothelial cells, altering endothelial glycocalyx, and finally, inducing endothelial cell apoptosis. The glomerular endothelial dysfunction results in albuminuria. In addition, high glucose and by-products impair the endothelial repair capacities by reducing the number and function of endothelial progenitor cells. In this review, we summarize the mechanisms of renal endothelial toxicity of high glucose/glucose by-products, which encompass changes in synthesis of growth factors like TGF-β and VEGF, induction of oxidative stress and inflammation, and reduction of NO bioavailability. We finally present potential therapies to reduce endothelial dysfunction in diabetic kidney disease.
Objective
The role of interferon‐α (IFNα) in the pathogenesis of systemic lupus erythematosus (SLE) is strongly supported by gene expression studies. The aim of this study was to improve ...characterization of the blood IFN signature in adult SLE patients.
Methods
Consecutive patients were enrolled and followed up prospectively. Microarray data were generated using Illumina BeadChips. A modular transcriptional repertoire was used as a framework for the analysis.
Results
Our repertoire of 260 modules, which consisted of coclustered gene sets, included 3 IFN‐annotated modules (M1.2, M3.4, and M5.12) that were strongly up‐regulated in SLE patients. A modular IFN signature was observed in 54 of 62 patients (87%) or 131 of all 157 samples (83%). The IFN signature was more complex than expected, with each module displaying a distinct activation threshold (M1.2 < M3.4 < M5.12), thus providing a modular score by which to stratify SLE patients based on the presence of 0, 1, 2, or 3 active IFN modules. A similar gradient in modular IFN signature was observed within patients with clinically quiescent disease, for whom moderate/strong modular scores (2 or 3 active IFN modules) were associated with higher anti–double‐stranded DNA titers and lower lymphocyte counts than those in patients with absent/mild modular scores (0 or 1 active IFN modules). Longitudinal analyses revealed both stable (M1.2) and variable (M3.4 and M5.12) components of modular IFN signature over time in single patients. Interestingly, mining of other data sets suggested that M3.4 and M5.12 could also be driven by IFNβ and IFNγ.
Conclusion
Modular repertoire analysis reveals complex IFN signatures in SLE, which are not restricted to the previous IFNα signature, but which also involve IFNβ and IFNγ.
Objective
To assess the mortality profile of systemic lupus erythematosus (SLE) patients in France using multiple‐cause‐of‐death analysis.
Methods
Data were collected between 2000 and 2009 in the ...French Epidemiological Center for the Medical Causes of Death database, and death certificates issued upon the death of an adult for whom SLE was an underlying cause of death (UCD) or a non–underlying cause of death (NUCD) were evaluated using multiple‐cause‐of‐death analysis. Sex, age, sex ratio, standardized mortality rates, as well as frequency of the various causes of death were assessed, at both a national and a regional level. For the main causes of death, the observed number of deaths in relation to the expected number of deaths (O:E ratio) (standardized for age and sex) was calculated.
Results
During the study period, 1,593 deaths related to SLE were identified. The mean ± SD age at death was 63.5 ± 18.4 years and the sex ratio (female:male) was 3.5. The mean standardized mortality rate was 3.2 per 1 million people (range 2.7–4.1). When SLE was the UCD (n = 637), the main NUCDs were cardiovascular diseases (49.5%), infectious diseases (24.5%), and renal failure (23.2%). When SLE was an NUCD (n = 956), the most common UCDs were cardiovascular diseases (35.7%), neoplasms (13.9%), and infectious diseases (10.3%). The overall O:E ratio was >1 for infectious and cardiovascular diseases and renal failure (especially among people <40 years of age for the latter 2 causes), but was <1 for neoplasms.
Conclusion
Cardiovascular disease is the leading cause of death associated with SLE in France.
Patients with chronic kidney disease (CKD) have a much higher risk of cardiovascular diseases than the general population. Endothelial dysfunction, which participates in accelerated atherosclerosis, ...is a hallmark of CKD. Patients with CKD display impaired endothelium‐dependent vasodilatation, elevated soluble biomarkers of endothelial dysfunction, and increased oxidative stress. They also present an imbalance between circulating endothelial populations reflecting endothelial injury (endothelial microparticles and circulating endothelial cells) and repair (endothelial progenitor cells). Endothelial damage induced by a uremic environment suggests an involvement of uremia‐specific factors. Several uremic toxins, mostly protein‐bound, have been shown to have specific endothelial toxicity: ADMA, homocysteine, AGEs, and more recently, p‐cresyl sulfate and indoxyl sulfate. These toxins, all poorly removed by hemodialysis therapies, share mechanisms of endothelial toxicity: they promote pro‐oxidant and pro‐inflammatory response and inhibit endothelial repair. This article (i) reviews the evidence for endothelial dysfunction in CKD, (ii) specifies the involvement of protein‐bound uremic toxins in this dysfunction, and (iii) discusses therapeutic strategies for lowering uremic toxin concentrations or for countering the effects of uremic toxins on the endothelium.
In chronic kidney disease (CKD), uremic solutes accumulate in blood and tissues. These compounds probably contribute to the marked increase in cardiovascular risk during the progression of CKD. The ...uremic solutes indoxyl sulfate and indole-3-acetic acid (IAA) are particularly deleterious for endothelial cells. Here we performed microarray and comparative PCR analyses to identify genes in endothelial cells targeted by these two uremic solutes. We found an increase in endothelial expression of tissue factor in response to indoxyl sulfate and IAA and upregulation of eight genes regulated by the transcription factor aryl hydrocarbon receptor (AHR). The suggestion by microarray analysis of an involvement of AHR in tissue factor production was confirmed by siRNA inhibition and the indirect AHR inhibitor geldanamycin. These observations were extended to peripheral blood mononuclear cells. Tissue factor expression and activity were also increased by AHR agonist dioxin. Finally, we measured circulating tissue factor concentration and activity in healthy control subjects and in patients with CKD (stages 3–5d), and found that each was elevated in patients with CKD. Circulating tissue factor levels were positively correlated with plasma indoxyl sulfate and IAA. Thus, indolic uremic solutes increase tissue factor production in endothelial and peripheral blood mononuclear cells by AHR activation, evoking a ‘dioxin-like’ effect. This newly described mechanism of uremic solute toxicity may help understand the high cardiovascular risk of CKD patients.
Objective
Recent studies have highlighted that systemic lupus erythematosus (SLE) is characterized by different types of symptoms: type 1 symptoms related to inflammation and disease activity and ...type 2 symptoms such as fatigue, anxiety-depression, and pain. Our aim was to investigate the relation between type 1 and type 2 symptoms, and their impact on health-related quality of life (HRQoL) in SLE.
Methods
A literature review was conducted about disease activity/type1 and type 2 symptoms. Articles in English published after 2000 were located on Medline via Pubmed. The articles chosen evaluated at least one type 2 symptom or HRQoL using a validated scale in adult patients.
Results
Overall, 182 articles were analyzed and 115 were retained including 21 randomized, controlled trials and corresponding to 36 831 patients. We found that in SLE, inflammatory activity/type 1 symptoms were mostly uncorrelated with type 2 symptoms and/or HRQoL. Several studies even showing an inverse relationship. No or weak correlation was observed in 85, 3% (92, 6%), 76, 7% (74, 4%) and 37, 5% (73, 1%) of studies (patients) for fatigue, anxiety-depression, and pain, respectively. For HRQoL, no or weak correlation was observed in 77, 5% of studies (88% of patients).
Conclusion
Type 2 symptoms are poorly correlated with inflammatory activity/type 1 symptoms in SLE. Possible explanations and implications for clinical care and therapeutic evaluation are discussed.
Endothelial microparticles (EMP) are complex vesicular structures that can be shed by activated or apoptotic endothelial cells. EMP are composed of a phospholipid bilayer that exposes transmembrane ...proteins and receptors and encloses cytosolic components such as enzymes, transcription factors and mRNA derived from their parent cells. Thus, EMP behave as biological conveyors playing a key role in the tuning of vascular homeostasis. This review focuses on the multifaceted roles of EMP, notably in coagulation, inflammation and angiogenesis and also on the mechanisms that trigger their formation. In this context, EMP could compromise vascular homeostasis and then represent key players in the pathogenesis of several inflammatory and thrombotic diseases. Consequently, elucidating their role and their mechanisms of formation will bring new insights into the understanding of endothelial-associated diseases. Moreover, in the future, it can open novel therapeutic perspectives based on the inhibition of EMP release.
Objective
Lupus is a chronic complex autoimmune disease. Non-adherence to treatment can affect patient outcomes. Considering patients’ preferences into medical decisions may increase acceptance to ...their medication. The PREFERLUP study used unsupervised clustering analysis to identify profiles of patients with similar treatment preferences in an online community of French lupus patients.
Methods
An online survey was conducted in adult lupus patients from the Carenity community between August 2018 and April 2019. Multiple Correspondence Analysis (MCA) was used with three unsupervised clustering methods (hierarchical, kmeans and partitioning around medoids). Several indicators (measure of connectivity, Dunn index and Silhouette width) were used to select the best clustering algorithm and choose the number of clusters.
Results
The 268 participants were mostly female (96%), with a mean age of 44.3 years 83% fulfilled the American College of Rheumatology (ACR) self-reported diagnostic criteria for systemic lupus erythematosus. Overall, the preferred route of administration was oral (62%) and the most important feature of an ideal drug was a low risk of side-effects (32%). Hierarchical clustering identified three clusters. Cluster 1 (59%) comprised patients with few comorbidities and a poor ability to identify oncoming flares; 84% of these patients desired oral treatments with limited side-effects. Cluster 2 (13%) comprised younger patients, who had already participated in a clinical trial, were willing to use implants and valued the compatibility of treatments with pregnancy. Cluster 3 (28%) comprised patients with a longer lupus duration, poorer control of the disease and more comorbidities; these patients mainly valued implants and injections and expected a reduction of corticosteroid intake.
Conclusions
Different profiles of lupus patients were identified according to their drug preferences. These clusters could help physicians tailor their therapeutic proposals to take into account individual patient preferences, which could have a positive impact on treatment acceptance and then adherence. The study highlights the value of data acquired directly from patient communities.
Systemic necrotizing vasculitis comprises a group of diseases resembling polyarteritis nodosa and anti-neutrophil cytoplasmic antibody-associated vasculitis (ANCA): granulomatosis with polyangiitis, ...eosinophilic granulomatosis with polyangiitis, and microscopic polyangiitis. The definitive diagnosis is made in cooperation with a reference center for autoimmune diseases and rare systemic diseases or a competency center. The management goals are: to obtain remission and, in the long term, healing; to reduce the risk of relapses; to limit and reduce the sequelae linked to the disease; to limit the side effects and the sequelae linked to the treatments; to improve or at least maintain the best possible quality of life; and to maintain socio-professional integration and/or allow a rapid return to school and/or professional activity. Information and therapeutic education of the patients and those around them are an integral part of the care. All health professionals and patients should be informed of the existence of patient associations. The treatment of vasculitis is based on variable combinations of glucocorticoids and immunosuppressants, chosen and adapted according to the disease concerned, the severity and/or extent of the disease, and the underlying factors (age, kidney function, etc.). Follow-up clinical and paraclinical examinations must be carried out regularly to clarify the progression of the disease, detect and manage treatment failures and possible relapses early on, and limit sequelae and complications (early then late) related to the disease or treatment. A distinction is made between the induction therapy, lasting approximately 3-6 months and aimed at putting the disease into remission, and the maintenance treatment, lasting 12-48 months, or even longer. The role of the increase or testing positive again for ANCA as a predictor of a relapse, which has long been controversial, now seems to have greater consensus: Anti-myeloperoxidase ANCAs are less often associated with a relapse of vasculitis than anti-PR3 ANCA.
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