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Objective The aim was to evaluate the most relevant cell populations involved in vascular homeostasis as potential biomarkers of SLE-related cardiovascular disease (CVD). Methods Low-density granulocytes (LDGs), monocyte subsets, endothelial progenitor cells, angiogenic T (Tang) cells, CD4+CD28null and Th1/Th17 lymphocytes and serum cytokine levels were quantified in 109 SLE patients and 33 controls in relationship to the presence of subclinical carotid atheromatosis or cardiovascular disease. A second cohort including 31 recent-onset SLE patients was also included. Results Raised monocyte and LDG counts, particularly those LDGs negative for CD16/CD14 expression (nLDGs), in addition to the ratios of monocytes and nLDGs to high-density lipoprotein-cholesterol (HDLc) molecules (MHR and nLHR, respectively), were present in SLE patients with traditional risk factors or subclinical atheromatosis but not in those who were CV-free, thus revealing their value in the identification of patients at risk of CVD, even at the onset of disease. Accordingly, nLDGs were correlated positively with carotid intima–media thickness (cIMT) and with inflammatory markers (CRP and IL-6). A bias towards more differentiated monocyte subsets, related to increased IFN-α and IL-17 serum levels, was also observed in patients. Intermediate monocytes were especially expanded, but independently of their involvement in CVD. Finally, CD4+CD28null, Th17 and Th1 lymphocytes were increased, with CD4+CD28null and Th17 cells being associated with cIMT, whereas endothelial progenitor and Tang cell levels were reduced in all SLE patients. Conclusion The present study highlights the potential use of MHR and nLHR as valuable biomarkers of CVD risk in SLE patients, even at diagnosis. The increased amounts of nLDGs, monocytes, Th17 and senescent-CD28null subsets, coupled with reduced pro-angiogenic endothelial progenitor cells and Tang cells, could underlie the development of atheromatosis in SLE. [ABSTRACT FROM AUTHOR]

Objective The aim was to evaluate whether T cell subsets and the lipid profile could be linked to the cardioprotective effect of IgM anti-phosphorylcholine (PC) antibodies in SLE. Methods Anti-PC antibodies were quantified by ELISA in 197 patients and 99 controls and analysed in relationship to clinical features, treatments and serum lipids. Carotid atheromatosis was evaluated by ultrasonography; Th1, Th17, Treg and CD4+CD28null cells by flow cytometry; and cytokine serum levels by immunoassays, in a subgroup of 120 SLE patients and 33 controls. Results IgM anti-PC serum levels were reduced in SLE patients compared with controls (P < 0.001) and were associated with age (β= −0.252; P = 0.002), high-density lipoprotein (HDL; β = 0.271; P = 0.001), low-density lipoprotein (LDL; β= −0.192; P = 0.017) and glucocorticoid treatment (β= −0.201; P = 0.012), whereas the IgG-to-IgM anti-PC ratio was increased (P = 0.007) and associated with age (β = 0.194; P = 0.028) and SLEDAI (β = 0.250; P = 0.005). Also, patients with clinical or subclinical cardiovascular disease exhibited reduced IgM anti-PC levels compared with their cardiovascular disease-free counterparts, regardless of glucocorticoid usage (P = 0.001). CD4+CD28null and Th17 cells were increased in SLE patients compared with controls (P < 0.01) and correlated inversely with IgM anti-PC levels. These associations were observed in patients displaying high triglyceride or low HDL levels, even after adjusting for clinical parameters and treatments (CD4+CD28null: β = −0.455, P = 0.001; Th17: β= −0.280, P = 0.035), but not in those with a normal lipid profile. High triglyceride and low HDL profiles were related to low IgM anti-PC and Treg levels, respectively, whereas both lipid profiles were associated with inflammatory markers and cytokines. Conclusion The present study provides evidence for an association of IgM anti-PC antibodies with pro-atherogenic T cell subsets in SLE, with a high triglyceride/low HDL lipid profile playing a facilitating major role. [ABSTRACT FROM AUTHOR]

Introduction: The role of the human intestinal microbiota in the maintenance of a healthy physiological condition, as well as its relation to the development of disease, remains to be clarified. Current evidence suggests that intestinal microbes could be involved in the initiation and amplification of autoimmune diseases, including rheumatoid arthritis and systemic lupus erythematosus (SLE). Despite recent progress in understanding how these microbes influence the pathophysiology of lupus, studies are still limited. Areas covered: In this review, we have tried to summarize the most relevant findings that have contributed to our understanding of the links between the human intestinal microbiota and the development of lupus. We also describe the potential role of individual microbial players in the physiology of lupus, and how they can shape relevant immune responses. Expert commentary: Culture-independent techniques based on massive sequencing represent a powerful tool to unravel the biological activity of gut microbes. Current data demonstrates that, depending on the pattern of intestinal microorganisms or the presence of specific bacteria, different responses related to lupus physiology can be triggered. Fecal microbiota transplantation, live biotherapeutics, or dietary interventions targeting the microbiota will likely become a treatment for SLE. [ABSTRACT FROM AUTHOR]

Background Immune cells under chronic inflammation shed microparticles (MPs) that could fuel the inflammatory responses and atherosclerosis typically presented in systemic lupus erythematosus (SLE). This study analyzes total and subset-specific MPs from SLE patients and their possible influence on clinical features, leukocyte activation and serum cytokines. Methods Total MPs and those derived from platelets, endothelial cells, monocytes, granulocytes and T-cells were quantified in plasma of 106 SLE patients and 33 healthy controls by flow cytometry. MP amounts were analyzed according to clinical manifestations, blood leukocyte populations and circulating cytokines (IFNα, TNFα, IL-10, BLyS, IL-17, IL-1β, CXCL10, CCL-2, CCL3, leptin). Finally, the in vitro effect of SLE-isolated MPs on the leukocyte activation status was analyzed. Results Total circulating MPs in SLE patients were related to increased disease duration and the presence of cardiovascular disease. Furthermore, patients displayed increased counts of MPs from platelets, monocytes and T-lymphocytes, especially in SLE patients with disease activity or with TNFα high -profile. Accordingly, MPs were associated with increased expression of activation markers in blood T-cells and monocytes. Finally, analyses propose a role of glucocorticoids in MPs generation and leukocyte activation since both fresh and cultured T-cells under this treatment presented higher IL-10 and CD25 production. Conclusions The altered profile of subset-specific SLE-MPs was influenced by the disease activity and altered status of leukocyte native cells, also associated with a TNFα high -profile. Translational results SLE patients, especially those with disease activity, displayed increased counts of MPs derived from platelets, monocytes and T-lymphocytes, which were more frequently found in TNFα high -type patients. The origin of such SLE-MP subsets seems to be related to the over-activated status of T-cells and monocytes characteristic of these patients. Ex vivo and in vitro analyses propose a role of glucocorticoids in the generation of circulating MPs and leukocyte activation in SLE patients. [ABSTRACT FROM AUTHOR]

Metabolic impairments are a frequent hallmark of systemic lupus erythematosus (SLE). Increased serum levels of free fatty acids (FFA) are commonly found in these patients, although the underlying causes remain elusive. Recently, it has been suggested that factors other than inflammation or clinical features may be involved. The gut microbiota is known to influence the host metabolism, the production of short-chain fatty acids (SCFA) playing a potential role. Taking into account that lupus patients exhibit an intestinal dysbiosis, we wondered whether altered FFA levels may be associated with the intestinal microbial composition in lupus patients. To this aim, total and specific serum FFA levels, fecal SCFA levels, and gut microbiota composition were determined in 21 SLE patients and 25 healthy individuals. The Firmicutes to Bacteroidetes (F/B) ratio was strongly associated with serum FFA levels in healthy controls (HC), even after controlling for confounders. However, this association was not found in lupus patients, where a decreased F/B ratio and increased FFA serum levels were noted. An altered production of SCFA was related to the intestinal dysbiosis in lupus, while SCFA levels paralleled those of serum FFA in HC. Although a different serum FFA profile was not found in SLE, specific FFA showed distinct patterns on a principal component analysis. Immunomodulatory omega-3 FFA were positively correlated to the F/B ratio in HC, but not in SLE. Furthermore, divergent associations were observed for pro- and anti-inflammatory FFA with endothelial activation biomarkers in lupus patients. Overall, these findings support a link between the gut microbial ecology and the host metabolism in the pathological framework of SLE. A potential link between intestinal dysbiosis and surrogate markers of endothelial activation in lupus patients is supported, FFA species having a pivotal role. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to investigate the cellular populations and regulatory factors responsible for B-lymphocyte stimulator (BLyS) overexpression in SLE patients.Methods. Surface and intracellular BLyS levels were quantified by flow cytometry in healthy and SLE monocytes cultured in the presence of TNF-α, IFN-α, IFN-γ, GM-CSF and SLE immune complexes (SLE-ICs), while soluble BLyS was measured by ELISA. Also, both surface and intracellular BLyS expression by different cell subsets was determined in 23 SLE patients and 16 healthy controls. Disease activity was assessed using classic BILAG index.Results. In vitro experiments using healthy monocytes showed that IFN-α and SLE-ICs induced a progressive increase in surface-bound BLyS with respect to the intracellular stores. IFN-α-treated SLE monocytes, especially from patients with high anti-dsDNA levels or disease activity, exhibited higher intracellular levels of BLyS that was mobilized to the membrane more rapidly and subsequently released. Furthermore, ex vivo analysis of SLE patients revealed up-regulated BLyS expression in B cells, myeloid and plasmacytoid dendritic cells (DCs), whereas active patients had an increased surface:intracellular BLyS ratio in monocytes and myeloid DCs.Conclusion. Monocyte BLyS induction and mobilization from intra- to extracellular compartments seems to be influenced by IFN-α and disease activity or anti-dsDNA levels. Accordingly, monocytes and myeloid DCs from active patients presented the highest membrane-bound:intracellular BLyS ratio. In addition, expression levels in several blood cells support the existence of generalized immune stimulation in SLE patients. [ABSTRACT FROM PUBLISHER]

Highlights: [•] IFNα enhances TNFα and STAT4 expression in LPS-activated monocytes. [•] Antimalarials downregulate in vitro TNFα- and STAT4-induction on monocytes. [•] Antimalarial drugs reduce STAT4 expression in SLE patients with high IFNα levels. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to investigate the endothelial progenitor cell population in SLE and early RA patients and its potential relationships with disease features and cytokine serum levels.Methods. Endothelial progenitor cells (EPCs), mature EPCs (mEPCs) and endothelial cells (ECs) were measured in peripheral blood samples from 83 SLE and 85 early RA patients and 39 healthy controls by flow cytometry on the basis of CD34, VEGF receptor 2 and CD133 expression. Serum levels of IL-1β, IL-6, IL-8, IL-17, VEGF-A, IFN-α, TGF-β and GM-CSF were quantified by immunoassays. Clinical and immunological data were obtained by reviewing clinical histories.Results. Circulating EPCs were increased in SLE but not in early RA patients associated with an enhanced CD34+ bone marrow-progenitor cell release but unrelated to disease features. The amount of mEPCs, however, was significantly higher in SLE patients presenting anti-SSA/SSB antibodies and/or malar rash, whereas the presence of specific autoantibodies was associated with EC counts in early RA and SLE patients. As expected, most cytokines tested were altered in both diseases but, interestingly, IFN-α levels, and to a lesser extent IL-6 and IL-1β, were associated with CD133 loss and increased mEPC number, whereas VEGF and TGF-β seem to exert an opposite effect.Conclusion. Our results show that high IFN-α levels and/or the presence of disease-specific antibodies may identify a group of SLE patients with increased mEPC and EC counts, and consequently probably defective endothelial repair, thus supporting their use as surrogate biomarkers of endothelial damage and high cardiovascular risk. [ABSTRACT FROM AUTHOR]

Objective. To investigate the relative amounts of Th17 and Th1 cells present in SLE patients and the possible effects of treatments or disease features on these populations.Methods. Peripheral blood mononuclear cells were collected from 75 SLE patients and 19 healthy controls and the proportion of Th17 and Th1 populations were assessed by flow cytometry measuring the amount of IL-17 and IFN-γ-producing cells. Gene expression of signal transducers and activators of transcription 3 (STAT3), STAT4, IL-6R and IL-12R were determined in 30 patients and 8 healthy individuals by real-time RT–PCR. Data were related to clinical and immunological parameters and to the treatment followed during the past 3 months.Results. Th17 cells and the Th17/Th1 ratio were significantly increased in SLE patients treated with glucocorticoids compared with healthy individuals, untreated patients or those under other treatments. No association was detected with clinical parameters, but patients with anti-ENA antibodies also displayed increased Th17 responses. Disease activity (SLEDAI) is associated with the Th17/Th1 index only in glucocorticoid-treated patients. In line with these results, gene expression of STAT3 and IL-6R was up-regulated in patients taking these drugs. Accordingly, we found a positive correlation between the Th17/Th1 ratio and STAT3 levels.Conclusions. The present work provides the first evidence that aberrant Th17/Th1 balance in SLE is linked to the use of glucocorticoids and suggests that the up-regulatory effect of these drugs on the Th17 population could be associated with their ability to increase STAT3 and IL-6R expression. Additionally, anti-ENA positivity could represent a potential biomarker for Th17 bias. [ABSTRACT FROM PUBLISHER]

The production of two regulators of the inflammatory response, interleukin 10 (IL-10) and tumor necrosis factor α (TNFα), has been found to be deeply deregulated in SLE patients, suggesting that these cytokines may be involved in the pathogenesis of the disease. Genetic polymorphisms at the promoter regions of IL-10 and TNFα genes have been associated with different constitutive and induced cytokine production. Given that individual steady-state levels of these molecules may deviate an initial immune response towards different forms of lymphocyte activation, functional genetic variants in their promoters could influence the development of SLE. The present review summarizes the information previously reported about the involvement of IL-10 and TNFα genetic variants on SLE appearance, clinical phenotype, and outcome. We show that, in spite of the heterogeneity of the populations studied, the existing knowledge points towards a relevant role of IL-10 and TNFα genotypes in SLE. [ABSTRACT FROM AUTHOR]

Increasing evidence supports the involvement of autophagy in the etiopathology of autoimmune diseases. Despite the identification of autophagy-related protein (Atg)-5 as one of the susceptibility loci in systemic Lupus erythematosus (SLE), the consequences of the carriage of these mutations for patients remain unclear. The present work analyzed the association of Atg5 rs573775 single nucleotide polymorphism (SNP) with SLE susceptibility, IFNα, TNFα and IL-10 serum levels, and clinical features, in 115 patients and 170 healthy individuals. Patients who where carriers of the rs573775 T* minor allele presented lower IFNα levels than those with the wild genotype, whereas the opposite result was detected for IL-10. Thus, since IL-10 production was regulated by rs1800896 polymorphisms, we evaluated the effect of this Atg5 mutation in genetically high and low IL-10 producers. Interestingly, we found that the rs573775 T* allele was a risk factor for SLE in carriers of the high IL-10 producer genotype, but not among genetically low producers. Moreover, IL-10 genotype influences SLE features in patients presenting the Atg5 mutated allele. Specifically, carriage of the rs573775 T* allele led to IL-10 upregulation, reduced IFNα and TNFα production and a low frequency of cytopenia in patients with the high IL-10 producer genotype, whereas patients with the same Atg5 allele that were low IL-10 producers presented reduced amounts of all these cytokines, had a lower prevalence of anti-dsDNA antibodies and the latest onset age. In conclusion, the Atg5 rs573775 T* allele seems to influence SLE susceptibility, cytokine production and disease features depending on other factors such as functional IL-10 genotype. [ABSTRACT FROM AUTHOR]

Background: Systemic lupus erythematosus (SLE) is a chronic infl ammatory disease of autoimmune nature, in which oxidative stress is implicated.Aim: Compare the concentrations of dietary and blood antioxidants, as well as gut microbiota, with serum malondialdehyde (MDA) and C reactive protein (CRP) in 21 subjects suffering from non-active systemic lupus erythematosus (SLE) and 21 age and gender-matched controls.Methods: General biochemical parameters and CRP were determined by enzymatic methods: copper, zinc and selenium by inductively coupled plasma mass spectrometry (ICP-MS), MDA and total antioxidant capacity (TAC) by spectrophotometric methods, gut microbiota by metagenomic analyses and dietary intake by means of food frequency questionnaire.Results: No significant differences were found in diet between lupus patients and the control group, with the exception of trans fatty acids intake, which was higher in patients. In addition, higher concentration of serum copper and lower of zinc in SLE were found. Serum copper was positively associated with CRP and also, this protein with the proportion of Lentisphaerae, ProteobacteriaandVerrucomicrobiain feces. Moreover, MDA levels displayed inverse correlations with the Cyanobacteriaand Firmicutesgroups, while Actinobacteria showed a positive association. The lupus subjects with presence of anti-SSA/Ro were related to higher levels of serum zinc.Conclusion: These results could be useful in the future to go deeper into the understanding of this complex disease. [ABSTRACT FROM AUTHOR]

Abstract: In this work we studied CD4+FOXP3+ populations in systemic lupus erythematosus (SLE) and the relationship with Th cytokine production. We found an increment in CD25−FOXP3+ population in SLE associated with CD4+ downregulation and disease progression. CD25low cells were also upregulated and showed increased percentages of FOXP3+ and CD127−/low cells, supporting the activated status of SLE lymphocytes. Despite the normal levels of CD25highFOXP3+ cells, the negative correlations observed in controls with the frequency of IFNγ, TNFα and IL-10 secreting cells were disrupted in patients, supporting a defective Treg function. Also, CD25high cells showed an altered balance in the production of these cytokines. In addition, CD25highFOXP3+ cells correlated directly with IL-17A and IL-8 but not with TGFβ in SLE. The increased proportion of IL-17+ cells among the CD25high subset and the positive correlation between IL-17 levels and Treg cells suggest a trans-differentiation of Treg into Th17 cells in SLE. [Copyright &y& Elsevier]

Abstract: Recent studies have shown the capacity of corticoids to increase forkhead box p3 (FOXP3) expression, which suggests that these drugs may be able to generate regulatory T cells (Treg). Therefore, corticoids may possibly be employed in protocols to generate or expand Treg cells with the aim of being used in cell transfer therapy. However, given that in humans FOXP3 is not necessarily associated with regulatory function, it is of great importance to ascertain whether FOXP3-expressing cells generated with corticoids are “truly” Treg cells. To this end, we studied the effect of dexamethasone on both human activated lymphocytes and in vitro generated Treg cells as well as regulatory activity of CD4+CD25high cells from SLE patients users and non users of prednisone. Results show that dexamethasone markedly enhances FOXP3 expression and generates CD25high cells with phenotypic characteristics attributable to natural Treg cells. Unexpectedly, in spite of their hyporesponsiveness and enhanced FOXP3 expression, these cells did not exert suppressive activity. Moreover, although dexamethasone was able to enhance FOXP3 expression in in vitro generated Treg cells, once again this effect was not correlated with increased regulatory activity. These results were supported by the fact that CD4+CD25high cells from steroid-treated SLE patients did not show a higher antiproliferative function than those from non-steroid-treated patients. We conclude that the increment on FOXP3 expression caused by dexamethasone is not connected with regulatory function, supporting the fact that FOXP3 expression in humans is not an exclusive attribute of Treg cells. Subsequently, the use of FOXP3 as a Treg cell marker must be done cautiously, especially in patients with systemic inflammatory diseases or those under corticoid treatment. [Copyright &y& Elsevier]

Abstract: A role of natural regulatory CD4+CD25+ T cells in peripheral tolerance has been established, but a causative role of these cells has not been proved in human autoimmune diseases. Functional alterations have been reported in arthritis and contradictory results have been published in systemic lupus erythematosus (SLE). In this study, the CD4+CD25+ T cell function was studied in 12 SLE patients (6 with only antimalarials and 6 also with corticoids treatment) in parallel to 12 healthy controls. CD4+CD25− T cells were cocultured with allogenic monocyte derived dendritic cells (MDDC) and CD4+CD25+ T cells were added. Proliferation was measured by [3H]-thymidine incorporation and TNFα secretion was assessed by ELISA. A better anti-proliferative function of CD4+CD25+ T cells was found in patients than in controls (p =0.009), whereas higher TNFα secretion was found in patients (p =0.028). There were no significant differences regarding treatment. In summary, CD4+CD25+ T cells from SLE patients showed an undamaged anti-proliferative function. Our results and other authors'' have not proved a SLE causative role for CD4+CD25+ T cells. The reduced inhibitive function on TNFα secretion found in patients could have some implications in lupus pathogenesis. [Copyright &y& Elsevier]