Understanding the role of environmental factors in the development of systemic lupus erythematosus

The Role of Oxidative Stress in Epigenetic Changes Underlying Autoimmunity

Significance: Epigenetic dysregulation plays an important role in the pathogenesis and development of autoimmune diseases. Oxidative stress is associated with autoimmunity and is also known to alter epigenetic mechanisms. Understanding the interplay between oxidative stress and epigenetics will provide insights into the role of environmental triggers in the development of autoimmunity in genetically susceptible individuals. Recent Advances: Abnormal DNA and histone methylation patterns in genes and pathways involved in interferon and tumor necrosis factor signaling, cellular survival, proliferation, metabolism, organ development, and autoantibody production have been described in autoimmunity. Inhibitors of DNA and histone methyltransferases showed potential therapeutic effects in animal models of autoimmune diseases. Oxidative stress can regulate epigenetic mechanisms via effects on DNA damage repair mechanisms, cellular metabolism and the local redox environment, and redox-sensitive transcription factors and pathways. Critical Issues: Studies looking into oxidative stress and epigenetics in autoimmunity are relatively limited. The number of available longitudinal studies to explore the role of DNA methylation in the development of autoimmune diseases is small. Future Directions: Exploring the relationship between oxidative stress and epigenetics in autoimmunity will provide clues for potential preventative measures and treatment strategies. Inception cohorts with longitudinal follow-up would help to evaluate epigenetic marks as potential biomarkers for disease development, progression, and treatment response in autoimmunity. Antioxid. Redox Signal. 36, 423-440.

Therapeutic plasma exchange in a patient with acute motor axonal neuropathy subtype of Guillain-Barre syndrome and systemic lupus erythematosus

A young female in her early 20s with a history of systemic lupus erythematosus presented to the emergency department due to 4 days of progressive bilateral extremity weakness and numbness. The patient reported flu-like symptoms that had spontaneously recovered 2 weeks prior to her presentation. She was 10 weeks pregnant at presentation. Lumbar puncture study and electrical muscle stimulation (EMS) were consistent with acute motor axonal neuropathy subtype of Guillain-Barre syndrome (GBS). Patient also had increased proteinuria and renal biopsy performed that was consistent with lupus nephritis. Despite treatment with pulse dose corticosteroids and IVIG, the patient had minimal neurological improvement and with continued decline required intubation. Her pregnancy was terminated at this point and a course of therapeutic plasma exchange (TPE) was started. Patient was also treated with cyclophosphamide. The patient responded to the combination of therapy and had slow but gradual neurologic recovery as well as improvement of proteinuria. Here we describe a case of an acute motor axonal neuropathy (AMAN) subtype of GBS in a young woman with active SLE and current pregnancy at the time of the presentation. Concurrent GBS and active SLE in the setting of pregnancy may be more treatment resistant, and combination therapy including TPE, immunosuppression, and termination of pregnancy may be indicated.

New-Onset Systemic Lupus Erythematosus after mRNA SARS-CoV-2 Vaccination

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease resulting from the interaction of genetic and environmental factors. In addition, some antiviral vaccines have been associated with the onset of SLE. Few cases of SLE occurring after SARS-CoV-2 mRNA have been reported. Herein, we report the case of a 27-year-old woman with type I diabetes mellitus and family history of SLE who presented with symmetric inflammatory polyarthritis of the proximal interphalangeal joints, metacarpophalangeal joints, wrists, knees, and ankles two weeks after receiving the second dose of the SARS-CoV-2 mRNA-1273 vaccine. Laboratory results revealed positive antinuclear, anti-dsDNA, anti-Ro, and anti-La/SSB antibodies and low C4 levels. She was initially treated with low-dose prednisone and hydroxychloroquine. Hydroxychloroquine was discontinued after she developed an urticarial rash. Subsequently, mycophenolate mofetil was added after she developed proteinuria. This case highlights the importance of considering the diagnosis of SLE in patients who present with inflammatory polyarthritis after COVID-19 vaccination.

Tumor necrosis factor‑α in systemic lupus erythematosus: Structure, function and therapeutic implications (Review)

Tumor necrosis factor‑α (TNF‑α) is a pleiotropic pro‑inflammatory cytokine that contributes to the pathophysiology of several autoimmune diseases, such as multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis, psoriatic arthritis and systemic lupus erythematosus (SLE). The specific role of TNF‑α in autoimmunity is not yet fully understood however, partially, in a complex disease such as SLE. Through the engagement of the TNF receptor 1 (TNFR1) and TNF receptor 2 (TNFR2), both the two variants, soluble and transmembrane TNF‑α, can exert multiple biological effects according to different settings. They can either function as immune regulators, impacting B‑, T‑ and dendritic cell activity, modulating the autoimmune response, or as pro‑inflammatory mediators, regulating the induction and maintenance of inflammatory processes in SLE. The present study reviews the dual role of TNF‑α, focusing on the different effects that TNF‑α may have on the pathogenesis of SLE. In addition, the efficacy and safety of anti‑TNF‑α therapies in preclinical and clinical trials SLE are discussed.

DNA Methylation of CD70 Promoter in Juvenile Systemic Lupus Erythematosus

INTRODUCTION

Epigenetic alterations in pathogenesis of systemic lupus erythematosus (SLE) have gained more attention recently in adults. We assessed the methylation of CD70 promoter, a costimulatory molecule on T cells, in juvenile SLE (JSLE), and compared this to that found in controls and the literature of adult SLE patients.

METHODS

DNA methylation status was evaluated on peripheral blood from JSLE patients and healthy controls.

RESULTS

Twenty-five patients with JSLE and 24 healthy controls were compared. JSLE patients had lower unmethylated CpG islands compared to the control group (mean ± SD; 0.78 ± 0.42 vs 10503.80 ± 39796.95). However, the difference was not significant (P-value; 0.22).

CONCLUSION

Despite hypomethylation of CD70 gene promoter in CD4+ T-cells from adult patients with SLE, no statistically significant differences observed in patients with JSLE compared with healthy controls. This may suggest a mechanism different in JSLE patients than in adults.

Silica Induction of Diverse Inflammatory Proteome in Lungs of Lupus-Prone Mice Quelled by Dietary Docosahexaenoic Acid Supplementation

Repeated short-term intranasal instillation of lupus-prone mice with crystalline silica (cSiO2) induces inflammatory gene expression and ectopic lymphoid neogenesis in the lung, leading to early onset of systemic autoimmunity and rapid progression to glomerulonephritis. These responses are suppressed by dietary supplementation with the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA). Here, we tested the hypothesis that dietary DHA supplementation suppresses cSiO2-induced inflammatory proteins in bronchoalveolar alveolar lavage fluid (BALF) and plasma of lupus-prone mice. Archived tissue fluid samples were used from a prior investigation in which 6 wk-old lupus-prone female NZBWF1 mice were fed isocaloric diets containing 0 or 10 g/kg DHA for 2 wks and then intranasally instilled with 1 mg cSiO2 or vehicle once weekly for 4 wks. Cohorts were terminated at 1, 5, 9 or 13 wk post-instillation (PI). BALF and plasma from each cohort were analyzed by high density multiplex array profiling of 200 inflammatory proteins. cSiO2 time-dependently induced increases in the BALF protein signatures that were highly reflective of unresolved lung inflammation, although responses in the plasma were much less robust. Induced proteins in BALF included chemokines (e.g., MIP-2, MCP-5), enzymes (e.g., MMP-10, granzyme B), adhesion molecules (e.g., sE-selectin, sVCAM-1), co-stimulatory molecules (e.g., sCD40L, sCD48), TNF superfamily proteins (e.g., sTNFRI, sBAFF-R), growth factors (e.g., IGF-1, IGFBP-3), and signal transduction proteins (e.g., MFG-E8, FcgRIIB), many of which were blocked or delayed by DHA supplementation. The BALF inflammatory proteome correlated positively with prior measurements of gene expression, pulmonary ectopic lymphoid tissue neogenesis, and induction of autoantibodies in the lungs of the control and treatment groups. Ingenuity Pathway Analysis (IPA) revealed that IL-1β, TNF-α, and IL-6 were among the top upstream regulators of the cSiO2-induced protein response. Furthermore, DHA's effects were associated with downregulation of cSiO2-induced pathways involving i) inhibition of ARE-mediated mRNA decay, ii) bacterial and viral pattern recognition receptor activation, or iii) TREM1, STAT3, NF-κB, and VEGF signaling and with upregulation of PPAR, LXR/RXR and PPARα/RXRα signaling. Altogether, these preclinical findings further support the contention that dietary DHA supplementation could be applicable as an intervention against inflammation-driven autoimmune triggering by cSiO2 or potentially other environmental agents.

What can we learn from DNA methylation studies in lupus?

During the past twenty years, a wide range of studies have established the existence of epigenetic alterations, particularly DNA methylation changes, in lupus. Epigenetic changes might have different contributions in children-onset versus adult-onset lupus. DNA methylation alterations have been identified and characterized in relation to disease activity and damage, different lupus subtypes and responses to drugs. However, to date there has been no practical application of these findings in the clinical milieu. In this article, we provide a review of key studies showing the relationship between DNA methylation and the many clinical aspects related to lupus. We also propose several options, in relation to the range of methodological developments and experimental design, that could optimize these findings and make them amenable for use in clinical practice.

Frequency-dependent effect of intravenous administration of human adipose-derived mesenchymal stem cell therapy for severe Systemic Lupus Erythematosus: A case report

Systemic Lupus Erythematosus (SLE) is a chronic autoimmune disease that involves abnormal activation of immune response, affecting multiple organs, including joints, kidneys, lungs, skin, and the hematopoietic system, thereby impairing their normal function. Despite there being no cure for SLE, Mesenchymal Stem Cell (MSC) therapy offers hope for SLE patients because of its potent role in immunomodulation. Here, we report a case of a 65-year-old female battling with SLE for almost 30 years and on a treatment regimen consisting of several medications. Given the level of immunosuppression associated with conventional SLE treatments, the subject was initially enrolled as a participant in a study protocol designed to provide immune protection against COVID-19. The subject received multiple infusions of autologous Hope Biosciences adipose-derived MSCs (HB-adMSCs) which significantly improved her SLE symptoms and functionality that led the patient's physician to discontinue her Rituximab regime. Based on her response to HB-adMSC therapy, the subject was approved to receive a set of nine infusion treatments to specifically treat her SLE symptoms. Over the course of ∼ one year, the first six infusions were given on a monthly basis, while the remaining three were administered bimonthly - each with a dose of 200 million HB-adMSCs. Since the beginning of the treatment, the subject showed remarkable improvements in her SLE symptoms, as demonstrated by changes in her SF-36 questionnaire responses, Visual Analog Scale (VAS) scores, and C-Reactive Protein (CRP) measurements; however, worsening of the symptoms was noted later during treatment course (when the frequency of infusions changed to bimonthly). Although the shift in remission-relapse cycle is not fully understood, however, the data suggest that treatment frequency might be the key player. No serious adverse events occurred during the entire treatment period. Further research is needed to evaluate the results of this study.

Role of Environment in Pediatric Rheumatic Diseases

Studying environmental risk factors for pediatric rheumatic diseases (PRD) is important because the identification of these factors may lead to strategies to prevent disease, and to new insights into pathogenesis and therapeutic targets. Compared with other chronic diseases, there are few environmental epidemiology studies in PRD. Although strong risk factors common to all PRDs have not been identified, some exposures including infection, smoke exposure, and ultraviolet radiation have been associated with several of them. High-technology studies, especially of microbiomics and metabolomics, are increasing and will likely lead to new understandings of the complex interplay between environment, genetics, and disease.

Recent advances in understanding the genetic basis of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a polygenic chronic autoimmune disease leading to multiple organ damage. A large heritability of up to 66% is estimated in SLE, with roughly 180 reported susceptibility loci that have been identified mostly by genome-wide association studies (GWASs) and account for approximately 30% of genetic heritability. A vast majority of risk variants reside in non-coding regions, which makes it quite challenging to interpret their functional implications in the SLE-affected immune system, suggesting the importance of understanding cell type-specific epigenetic regulation around SLE GWAS variants. The latest genetic studies have been highly fruitful as several dozens of SLE loci were newly discovered in the last few years and many loci have come to be understood in systemic approaches integrating GWAS signals with other biological resources. In this review, we summarize SLE-associated genetic variants in both the major histocompatibility complex (MHC) and non-MHC loci, examining polygenetic risk scores for SLE and their associations with clinical features. Finally, variant-driven pathogenetic functions underlying genetic associations are described, coupled with discussion about challenges and future directions in genetic studies on SLE.

Association between toxic organochlorine levels in human serum and systemic lupus erythematosus

Organochlorines (OCs) are groups of highly toxic pesticides with known immunotoxicity. The present work aimed to study the potential association between serum residues of OCs and the risk of developing systemic lupus erythematosus (SLE) as well as correlating to the clinical-laboratory manifestations in a sample of Egyptian SLE patients. A cross-sectional study was conducted on 132 patients environmentally exposed to OCs. Patients were diagnosed as SLE based on the American College of Rheumatology (ACR) revised criteria. Systemic Lupus Erythematosus Disease Activity Index-2000 (SLEDAI-2K) score was calculated to stratify the disease severity. Blood and urine samples were collected to measure the levels of OCs, serological markers, and urinary protein. The most frequently detected OCs were p,p'-DDE; lindane; and hexachlorobenzene (HCB). The risk of developing SLE was significantly associated with detected p,p'-DDE and HCB (B value 7.704 and 14.33, respectively). Hexachlorobenzene, in addition, was significantly associated with increased SLEDAI-2K score and polycythemia. Lindane was significantly associated with hypocomplementemia, cardiac manifestations of SLE, anemia, and leucopenia. In conclusion, the detected OCs p,p'-DDE and HCB are associated with increased risk of SLE in Egyptian patients and correlates to the manifestations of disease severity.

Frequency, severity and costs of flares increase with disease severity in newly diagnosed systemic lupus erythematosus: a real-world cohort study, United States, 2004-2015

Objective

To evaluate frequency, severity and costs of flares in US patients with newly diagnosed SLE.

Methods

Adults diagnosed with SLE between January 2005 and December 2014 were identified from US commercial claims data linked to electronic medical records. Disease and flare severity during 1 year after diagnosis were classified as mild, moderate or severe using a claims-based algorithm. Study outcomes included frequency and severity of flares stratified by disease severity during the 1-year post-diagnosis period and all-cause healthcare costs of flares by severity at 30, 60 and 90 days after flare.

Results

Among 2227 patients, 26.3%, 51.0% and 22.7% had mild, moderate and severe SLE, respectively. The overall annual flare rate was 3.5 and increased with disease severity: 2.2, 3.7 and 4.2, respectively, for mild, moderate and severe SLE (p<0.0001). Patients with severe SLE had a higher annual severe flare rate (0.6) compared with moderate (0.1) or mild SLE (0; p<0.0001). Mean total all-cause costs at 30, 60 and 90 days after flare were $16 856, $22 252 and $27 468, respectively, for severe flares (mild flares: $1672, $2639 and $3312; moderate flares: $3831, $6225, $8582; (p<0.0001, all time points)). Inpatient costs were the primary driver of the increased cost of severe flares.

Conclusions

Flare frequency and severity in newly diagnosed patients with SLE increase with disease severity. After a flare, healthcare costs increase over the following 90 days by disease severity. Preventing flares or reducing flare rates and duration may improve outcomes and reduce healthcare costs.

How to prevent skin damage from air pollution part 2: Current treatment options

In the first part of this review, we have summarized the methods used to examine skin exposure to air pollution and the fundamental concept of skin-exposome interactions. Part 2 of this review focuses on dermatoses, whose aggravation or initiation by air pollution has been confirmed in evidence based medicine manner. Based on the model of photodermatology and photodermatoses, we propose a new concept of "polludermatoses." A key feature of this concept is identifying patients at risk, which will reveal the noxious effects of air pollutants on skin health. Identifying clinical signs of pollution-damaged skin could be beneficial in categorizing conditions caused or exacerbated by exposure to air pollution. Finally, we discuss the current treatment options and the pathogenetic processes targeted by these therapeutics or the development of novel treatment modalities.

TGFB1 +869 T > C (rs1800470) variant is independently associated with susceptibility, laboratory activity, and TGF-β1 in patients with systemic lupus erythematosus

The aim of this study was to evaluate the association of the +869 T > C (rs1800470) and -509 C > T (rs1800469) TGFB1 variants, individually or in haplotypes structure, with susceptibility, autoantibodies, disease activity, and TGF-β1 plasma levels in patients with systemic lupus erythematosus (SLE). The study included 203 patients with SLE and 165 healthy controls. TGFB1 variants were determined by real-time polymerase chain reaction (qPCR). Plasma levels of TGF-β1 were determined using immunofluorimetric assay. The TGFB1 + 869 CC genotype was associated with SLE susceptibility (OR: 1.710, 95%CI: 1.020-2.866, p = 0.042) and with reduction of C4 (p = 0.040) and TGF-β1 levels (p = 0.044). In addition, patients with TGFB1 + 869 TC and CC genotypes and positive anti-dsDNA had lower TGF-β1 levels than those with TT (p = 0.004). TGFB1 -509 TT genotype was associated with reduced levels of C4 (p = 0.032). There was no association between haplotypes and clinical and laboratory parameters. Our data demonstrated that the TGFB1 + 869 T > C variant could be used as a genetic marker for SLE susceptibility and both variants as predictors of laboratory activity. This is the first study to demonstrate that TGF-β1 levels could be modulated by the interaction between TGFB1 + 869 C allele, in homozygosity, or heterozygosity, and the presence of anti-dsDNA.

Gut Microbiome and Metabolites in Systemic Lupus Erythematosus: Link, Mechanisms and Intervention

Systemic lupus erythematosus (SLE), often considered the prototype of autoimmune diseases, is characterized by over-activation of the autoimmune system with abnormal functions of innate and adaptive immune cells and the production of a large number of autoantibodies against nuclear components. Given the highly complex and heterogeneous nature of SLE, the pathogenesis of this disease remains incompletely understood and is presumed to involve both genetic and environmental factors. Currently, disturbance of the gut microbiota has emerged as a novel player involved in the pathogenesis of SLE. With in-depth research, the understanding of the intestinal bacteria-host interaction in SLE is much more comprehensive. Recent years have also seen an increase in metabolomics studies in SLE with the attempt to identify potential biomarkers for diagnosis or disease activity monitoring. An intricate relationship between gut microbiome changes and metabolic alterations could help explain the mechanisms by which gut bacteria play roles in the pathogenesis of SLE. Here, we review the role of microbiota dysbiosis in the aetiology of SLE and how intestinal microbiota interact with the host metabolism axis. A proposed treatment strategy for SLE based on gut microbiome (GM) regulation is also discussed in this review. Increasing our understanding of gut microbiota and their function in lupus will provide us with novel opportunities to develop effective and precise diagnostic strategies and to explore potential microbiota-based treatments for patients with lupus.

Cytokine Profiling in Chinese SLE Patients: Correlations with Renal Dysfunction

Background

Systemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease that commonly causes kidney damage. Therefore, we measured plasma levels of cytokines that may be related to renal dysfunction in SLE patients.

Methods

To explore the differences between SLE patients with renal dysfunction and healthy volunteers, the levels of cytokines in plasma were screened using a human cytokine antibody array. Then, we chose fourteen of the elevated cytokines for verification with an expanded sample size by a human magnetic Luminex assay. Plasma samples were isolated from SLE patients (n = 72) and healthy volunteers (n = 8).

Results

Cytokine antibody array data showed elevated plasma cytokines in SLE patients with renal dysfunction compared with healthy volunteers. By using the human magnetic Luminex assay, we found that plasma levels of CHI3L1, GDF-15, IGFBP-2, MIF, ST2, TFF3, and uPAR were significantly higher in SLE patients than in healthy volunteers. Plasma levels of CXCL4 were significantly lower in the active group than in the inactive group, and plasma levels of CHI3L1, IGFBP-2, MIF, and MPO were significantly higher in the active group than in the inactive group. We also analyzed the correlation between plasma cytokine levels and the SLEDAI-2K, and our results showed that the plasma levels of the fourteen selected cytokines were weakly correlated or not correlated with the SLEDAI-2K. We further analyzed the correlation between cytokines and renal dysfunction. Plasma levels of GDF-15 and TFF3 were highly positively correlated with serum creatinine levels and 24-hour urine protein levels.

Conclusion

Our data suggest that plasma levels of GDF-15 and TFF3 are potential renal dysfunction markers in SLE patients, but plasma levels of these cytokines are not correlated with the SLEDAI-2K. Further study is warranted to determine how these cytokines regulate inflammatory responses and renal dysfunction in SLE.

Mine-site derived particulate matter exposure exacerbates neurological and pulmonary inflammatory outcomes in an autoimmune mouse model

The Southwestern United States has a legacy of industrial mining due to the presence of rich mineral ore deposits. The relationship between environmental inhaled particulate matter (PM) exposures and neurological outcomes within an autoimmune context is understudied. The aim of this study was to compare two regionally-relevant dusts from high-priority abandoned mine-sites, Claim 28 PM, from Blue Gap Tachee, AZ and St. Anthony mine PM, from the Pueblo of Laguna, NM and to expose autoimmune-prone mice (NZBWF1/J). Mice were randomly assigned to one of three groups (n = 8/group): DM (dispersion media, control), Claim 28 PM, or St. Anthony PM, subjected to oropharyngeal aspiration of (100 µg/50 µl), once per week for a total of 4 consecutive doses. A battery of immunological and neurological endpoints was assessed at 24 weeks of age including: bronchoalveolar lavage cell counts, lung gene expression, brain immunohistochemistry, behavioral tasks and serum autoimmune biomarkers. Bronchoalveolar lavage results demonstrated a significant increase in number of polymorphonuclear neutrophils following Claim 28 and St. Anthony mine PM aspiration. Lung mRNA expression showed significant upregulation in CCL-2 and IL-1ß following St. Anthony mine PM aspiration. In addition, neuroinflammation was present in both Claim 28 and St. Anthony mine-site derived PM exposure groups. Behavioral tasks resulted in significant deficits as determined by Y-maze new arm frequency following Claim 28 aspiration. Neutrophil elastase was significantly upregulated in the St. Anthony mine exposure group. Interestingly, there were no significant changes in serum autoantigens suggesting systemic inflammatory effects may be mediated through other molecular mechanisms following low-dose PM exposures.

Systemic Lupus Erythematosus Disease: An Overview of the Clinical Approach to Pathogenesis, Diagnosis, and Treatment

The systemic lupus erythematosus (SLE), commonly known as Lupus, is a rare and complex multisystem autoimmune disease where one’s immune system is overactive, and the body attacks its organ systems. SLE is a historically old disease described already in antiquity; it is an example of a chronic disease with physical, psychological, financial, and social implications for individuals diagnosed. It has inspired medical and basic biological scientists that focus on molecular biology, basic immunology, immunopathology, clinical science, genetics, and epidemiology. The syndrome is real in its existence-although hidden behind obstacles, cumbersome for patients and clinicians, and rebellious for scientists. There is currently no cure for SLE. The goal of treatment is to ease symptoms. This article will review information on the general approach to SLE therapy, focusing on currently approved therapies and novel approaches that might be used in the future.

Lipopolysaccharide-Enhanced Responses against Aryl Hydrocarbon Receptor in FcgRIIb-Deficient Macrophages, a Profound Impact of an Environmental Toxin on a Lupus-Like Mouse Model

Fc gamma receptor IIb (FcgRIIb) is the only inhibitory-FcgR in the FcgR family, and FcgRIIb-deficient (FcgRIIb^−/−) mice develop a lupus-like condition with hyper-responsiveness against several stimulations. The activation of aryl hydrocarbon receptor (Ahr), a cellular environmental sensor, might aggravate activity of the lupus-like condition. As such, 1,4-chrysenequinone (1,4-CQ), an Ahr-activator, alone did not induce supernatant cytokines from macrophages, while the 24 h pre-treatment by lipopolysaccharide (LPS), a representative inflammatory activator, prior to 1,4-CQ activation (LPS/1,4-CQ) predominantly induced macrophage pro-inflammatory responses. Additionally, the responses from FcgRIIb^−/− macrophages were more prominent than wild-type (WT) cells as determined by (i) supernatant cytokines (TNF-α, IL-6, and IL-10), (ii) expression of the inflammation associated genes (NF-κB, aryl hydrocarbon receptor, iNOS, IL-1β and activating-FcgRIV) and cell-surface CD-86 (a biomarker of M1 macrophage polarization), and (iii) cell apoptosis (Annexin V), with the lower inhibitory-FcgRIIb expression. Moreover, 8-week-administration of 1,4-CQ in 8 week old FcgRIIb^−/− mice, a genetic-prone lupus-like model, enhanced lupus characteristics as indicated by anti-dsDNA, serum creatinine, proteinuria, endotoxemia, gut-leakage (FITC-dextran), and glomerular immunoglobulin deposition. In conclusion, an Ahr activation worsened the disease severity in FcgRIIb^−/− mice possibly through the enhanced inflammatory responses. The deficiency of inhibitory-FcgRIIb in these mice, at least in part, prominently enhanced the pro-inflammatory responses. Our data suggest that patients with lupus might be more vulnerable to environmental pollutants.

Omega-3 Polyunsaturated Fatty Acid Intervention Against Established Autoimmunity in a Murine Model of Toxicant-Triggered Lupus

Workplace exposure to respirable crystalline silica dust (cSiO2) has been etiologically linked to the development of lupus and other human autoimmune diseases. Lupus triggering can be recapitulated in female NZBWF1 mice by four weekly intranasal instillations with 1 mg cSiO2. This elicits inflammatory/autoimmune gene expression and ectopic lymphoid structure (ELS) development in the lung within 1 week, ultimately driving early onset of systemic autoimmunity and glomerulonephritis. Intriguingly, dietary supplementation with docosahexaenoic acid (DHA), an ω-3 polyunsaturated fatty acid (PUFA) found in fish oil, beginning 2 week prior to cSiO2 challenge, prevented inflammation and autoimmune flaring in this novel model. However, it is not yet known how ω-3 PUFA intervention influences established autoimmunity in this murine model of toxicant-triggered lupus. Here we tested the hypothesis that DHA intervention after cSiO2-initiated intrapulmonary autoimmunity will suppress lupus progression in the NZBWF1 mouse. Six-week old NZWBF1 female mice were fed purified isocaloric diet for 2 weeks and then intranasally instilled with 1 mg cSiO2 or saline vehicle weekly for 4 consecutive weeks. One week after the final instillation, which marks onset of ELS formation, mice were fed diets supplemented with 0, 4, or 10 g/kg DHA. One cohort of mice (n = 8/group) was terminated 13 weeks after the last cSiO2 instillation and assessed for autoimmune hallmarks. A second cohort of mice (n = 8/group) remained on experimental diets and was monitored for proteinuria and moribund criteria to ascertain progression of glomerulonephritis and survival, respectively. DHA consumption dose-dependently increased ω-3 PUFA content in the plasma, lung, and kidney at the expense of the ω-6 PUFA arachidonic acid. Dietary intervention with high but not low DHA after cSiO2 treatment suppressed or delayed: (i) recruitment of T cells and B cells to the lung, (ii) development of pulmonary ELS, (iii) elevation of a wide spectrum of plasma autoantibodies associated with lupus and other autoimmune diseases, (iv) initiation and progression of glomerulonephritis, and (v) onset of the moribund state. Taken together, these preclinical findings suggest that DHA supplementation at a human caloric equivalent of 5 g/d was an effective therapeutic regimen for slowing progression of established autoimmunity triggered by the environmental toxicant cSiO2.

Smoking associates with distinct clinical phenotypes in patients with systemic lupus erythematosus: a nationwide Danish cross-sectional study

Objectives

SLE displays large clinical heterogeneity that beyond genetic factors may be determined by environmental exposures. In this Danish nationwide study, we aimed to determine if clinical subsets of SLE were associated with smoking history.

Methods

At each of six participating centres, incident or prevalent inpatients and outpatients with SLE were consecutively included. Manifestations forming the basis of SLE classification were registered in an electronic chart system. Patients also provided questionnaire-based data on environmental exposures, including smoking history. Hierarchical cluster analysis was conducted to determine and characterise subsets of patients with similar traits of disease manifestations. Levels of smoking exposure by pack-years were correlated to the identified SLE subsets, as well as discrete SLE manifestations.

Results

The cohort consisted of 485 patients (88% women and 92% Caucasian) with SLE of which 51% were ever smokers. Common disease manifestations comprised non-erosive arthritis (81%), malar rash (57%), lymphopenia (55%), photosensitivity (50%) and persistent proteinuria (41%). We identified three distinct phenotypic clusters characterised by their preponderance of (A) neurological, serosal and mucosal involvement; (B) renal, haematological and immunological disorders; and (C) acute and chronic skin manifestations. Cluster B was the youngest and had the lowest level of smoking exposure. Age-adjusted regression analyses showed that compared with never smokers a smoking history of >20 pack-years was associated with neurological disorder (OR=3.16), discoid rash (OR=2.22), photosensitivity (OR=2.19) and inversely with haematological disorder (OR=0.40), renal disorder (OR=0.40) and non-erosive arthritis (OR=0.45), p<0.05 for all.

Conclusions

Our findings support that SLE presents in varying clinical phenotypes and suggest that they may have differentiated associations with smoking history.

Chronic exposure to PM2.5 aggravates SLE manifestations in lupus-prone mice

Background

Air pollution causes negative impacts on health. Systemic lupus erythematosus (SLE) is an autoimmune disease with diverse clinical manifestations and multifactorial etiology. Recent studies suggest that air pollution can trigger SLE and induce disease activity. However, this association has not been deeply investigated. Thus, the aim of this study was to evaluate whether exposure to fine particulate matter (PM2.5) exacerbates SLE manifestations, focusing on renal complications, in a lupus-prone animal model. Female NZBWF1 mice were exposed daily to 600 μg/m³ of inhaled concentrated ambient particles (CAP) or filtered air (FA). Survival rate, body weight, weight of organs (kidney, spleen, thymus, liver and heart), blood cell count, proteinuria, kidney stereology, renal histopathology, gene expression and oxidative stress were analyzed.

Results

Female NZBW mice exposed to CAP showed decreased survival, increased circulating neutrophils, early onset of proteinuria and increased kidney weight with renal cortex enlargement when compared to NZBW mice exposed to FA.

Conclusions

This work shows that air pollution aggravates some SLE manifestations in lupus-prone mice. These results reinforce the need of reducing air pollutant levels in order to promote a better quality of life for individuals diagnosed with SLE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-021-00407-0.

Sex Hormones and Gender Influence the Expression of Markers of Regulatory T Cells in SLE Patients

Regulatory T cells have been implicated in the regulation and maintenance of immune homeostasis. Whether gender and sex hormones differentially influence the expression and function of regulatory T cell phenotype and their influence on FoxP3 expression remains obscure. We provide evidence in this study that the number and percent of human regulatory T cells (T_regs) expressing CD4⁺ and CD8⁺ are significantly reduced in healthy females compared to healthy males. In addition, both CD4⁺CD25^+hi and CD8⁺CD25^+hi subsets in healthy males have a 2-3 fold increase in FoxP3 mRNA expression compared to healthy females. Female SLE patients, compared to healthy women, have elevated plasma levels of estradiol and decreased levels of testosterone. Higher levels of testosterone correlate with higher expression of FoxP3 in CD4⁺CD25^hiCD127^low putative T_regs in women with SLE. Incubation of CD4⁺ regulatory T cells with 17β-estradiol at physiological levels generally decreased FoxP3 expression in females with SLE. These data suggest that females may be more susceptible than males to SLE and other autoimmune diseases in part because they have fewer T_regs and reduced FoxP3 expression within those cells due to normal E2 levels which suppress FoxP3 expression. In addition, low levels of plasma testosterone in women may further reduce the ability of the T_regs to express FoxP3. These data suggest that gender and sex hormones can influence susceptibility to SLE via effects on regulatory T cells and FoxP3 expression.

Calcineurin and Systemic Lupus Erythematosus: The Rationale for Using Calcineurin Inhibitors in the Treatment of Lupus Nephritis

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a broad spectrum of clinical presentations that can affect almost all organ systems. Lupus nephritis (LN) is a severe complication that affects approximately half of the systemic erythematosus lupus (SLE) patients, which significantly increases the morbidity and the mortality risk. LN is characterized by the accumulation of immune complexes, ultimately leading to renal failure. Aberrant activation of T cells plays a critical role in the pathogenesis of both SLE and LN and is involved in the production of inflammatory cytokines, the recruitment of inflammatory cells to the affected tissues and the co-stimulation of B cells. Calcineurin is a serine-threonine phosphatase that, as a consequence of the T cell hyperactivation, induces the production of inflammatory mediators. Moreover, calcineurin is also involved in the alterations of the podocyte phenotype, which contribute to proteinuria and kidney damage observed in LN patients. Therefore, calcineurin inhibitors have been postulated as a potential treatment strategy in LN, since they reduce T cell activation and promote podocyte cytoskeleton stabilization, both being key aspects in the development of LN. Here, we review the role of calcineurin in SLE and the latest findings about calcineurin inhibitors and their mechanisms of action in the treatment of LN.

Abnormal thymic B cell activation and impaired T cell differentiation in pristane-induced lupus mice

Changes in the thymus and potential mechanisms underlying the pathogenesis in pristane-induced lupus (PIL) mice are poorly understood. This study aimed to systematically and specifically examine changes in the thymus and the potential mechanisms responsible for immunological abnormalities in PIL mice. The results showed that PIL mice exhibit serious thymic hyperplasia, an elevated thymus index, a damaged histopathological structure and increased thymocyte apoptosis. We found that thymic T cell differentiation was impaired as the CD4⁺ CD8⁺ double-positive (DP) thymocyte frequency significantly decreased, becoming almost absent at 28 weeks after induction, while CD4 CD8^- double-negative (DN) thymocytes and CD4⁺ CD8^- single-positive (CD4⁺ SP) and CD4 CD8⁺ single-positive (CD8⁺ SP) cells were increased. This phenomenon might be explained by an inhibition of the DN-to-DP-cell transition and stimulation of DP cell conversion into CD4⁺ /CD8⁺ SP thymocytes. Moreover, we discovered a dramatic and abnormal increase in thymic B cells, that was associated with CD19, Irf8, Ebf1, Pax5, Irf4, Blk, CXCL13, CXCR5, CD79a, CD79b, Lyn, Syk, Btk, and BLNK gene accumulation, which exhibited positive interactions. We further verified that the mRNA expression of these genes was significantly upregulated and consistent with the RNA-seq results. These results suggest a role of these genes in the increase of B cells in the thymus of PIL mice. In summary, our results showed the changes in the thymus in PIL and elucidated the immunologic abnormalities of increased B cells, potentially providing insight into the associated molecular mechanisms and facilitating further research.

Epstein-Barr Virus and Systemic Autoimmune Diseases

Epstein-Barr Virus (EBV) is an extremely successful human herpes virus, which infects essentially all human beings at some time during their life span. EBV infection and the associated immune response results in production of antibodies (seroconversion), which occurs mainly during the first years of life, but may also happen during adolescence or later in life. Infection of adolescents can result in infectious mononucleosis, an acute serious condition characterized by massive lymphocytosis. Transmission of EBV mainly occurs through saliva but can rarely be spread through semen or blood, e.g. through organ transplantations and blood transfusions. EBV transmission through oral secretions results in infection of epithelial cells of the oropharynx. From the epithelial cells EBV can infect B cells, which are the major reservoir for the virus, but other cell types may also become infected. As a result, EBV can shuttle between different cell types, mainly B cells and epithelial cells. Moreover, since the virus can switch between a latent and a lytic life cycle, EBV has the ability to cause chronic relapsing/reactivating infections. Chronic or recurrent EBV infection of epithelial cells has been linked to systemic lupus erythematosus and Sjögren’s syndrome, whereas chronic/recurrent infection of B cells has been associated with rheumatoid arthritis, multiple sclerosis and other diseases. Accordingly, since EBV can shuttle between epithelial cells and B cells, the systemic autoimmune diseases often occur as overlapping syndromes with symptoms and characteristic autoantibodies (e.g. antinuclear antibodies and rheumatoid factors) reflecting epithelial and/or B cell infection.

Lupus animal models and neuropsychiatric implications

Systemic lupus erythematosus (SLE) that involves neurological complications is known as neuropsychiatric systemic lupus erythematosus (NPSLE). Research in humans is difficult due to the disease's great heterogeneity. Animal models are a resource for new discoveries. In this review, we examine experimental models of lupus that present neuropsychiatric manifestations. Spontaneous animal models such as NZB/W F1 and MRL/lpr are commonly used in NPSLE research; these models present few SLE symptoms compared to induced animal models, such as pristane-induced lupus (PIL). The PIL model is known to present eight of the main clinical and laboratory manifestations of SLE described by the American College of Rheumatology. Many cytokines associated with NPSLE are expressed in the PIL model, such as IL-6, TNF-α, and IFN. However, to date, NPSLE manifestations have been poorly studied in the PIL model. In this review article, we discuss whether the PIL model can mimic neuropsychiatric manifestations of SLE. Key Points • PIL model have a strong interferon signature. • Animals with PIL express learning and memory deficit.

Systematic review and meta-analysis of epidemiological studies on the association of occupational exposure to free crystalline silica and systemic lupus erythematosus

Objectives

Some evidence suggests that exposure to free crystalline silica may contribute to the risk of developing SLE. A systematic search was carried out for all published epidemiological studies concerning this association. A meta-analysis was conducted on relevant studies.

Methods

We searched PubMed and EMBASE databases for original articles published from 1960 to November 2019 in any language. In addition, we also searched the reference lists of included studies manually for additional relevant articles. Finally, seven studies were included in the systematic review and six studies in the meta-analysis (four case–control and two cohort studies). The odds ratio and 95% CI were calculated using a random effect meta-analysis.

Results

The meta-analysis of the studies, applying a random effect model, yielded an overall odds ratio of 3.49 (95% CI, 1.24, 9.83), with I2 = 92.36% (pronounced heterogeneity). We also stratified the meta-analysis by study design; case–control studies: odds ratio 1.85 (95% CI, 0.96, 3.59) with I2 = 75.92%; and cohort studies (cases with silicosis): odds ratio 9.71 (95% CI, 1.13, 83.58) with I2 = 72.65%.

Conclusions

The obtained results support the hypothesis of a possible association between occupational exposure to free crystalline silica and SLE, in particular at higher exposure levels, known to induce silicosis. The studies that have investigated this association are still scarce and the heterogeneity between the studies remains high. New studies are deemed necessary to confirm the association.

Omega-3 fatty acid intake suppresses induction of diverse autoantibody repertoire by crystalline silica in lupus-prone mice

Inhalation of crystalline silica (cSiO2) in the workplace is etiologically linked to lupus and other autoimmune diseases. Exposing lupus-prone NZBWF1 mice to respirable cSiO2 unleashes a vicious cycle of inflammation and cell death in the lung that triggers interferon-regulated gene expression, ectopic lymphoid structure (ELS) development, elevation of local and systemic autoantibodies (AAbs), and glomerulonephritis. However, cSiO2-induced inflammation and onset of autoimmunity can be prevented by inclusion of the ω-3 polyunsaturated fatty acid docosahexaenoic acid (DHA) into the diet of these mice. Since cSiO2 both causes cell death and interferes with efferocytosis, secondary necrosis of residual cell corpses might provide a rich and varied autoantigen (AAg) source in the lung. While it is known that the particle induces anti-nuclear and anti-dsDNA AAbs in NZBWF1 mice, the full extent of the cSiO2-induced AAb response relative to specificity and isotype is not yet understood. The purpose of this study was to test the hypotheses that cSiO2 exposure induces a wide spectrum of AAbs in the pulmonary and systemic compartments, and that dietary DHA intervention prevents these changes. Archived tissue fluid samples were obtained from a prior study in which NZBWF1 mice were fed purified isocaloric diets containing no DHA (control) or DHA corresponding calorically to human doses of 2 and 5 g/day. Mice were intranasally instilled with 1 mg cSiO2 or saline vehicle weekly for 4 weeks, then groups euthanized 1, 5, 9, or 13 weeks post-instillation (PI) of the last cSiO2 dose. Bronchoalveolar lavage fluid (BALF) and plasma from each time point were subjected to AAb profiling using a microarray containing 122 AAgs. cSiO2 triggered robust IgG and IgM AAb responses against lupus-associated AAgs, including DNA, histones, ribonucleoprotein, Smith antigen, Ro/SSA, La/SSB, and complement as early as 1 week PI in BALF and 5 weeks PI in plasma, peaking at 9 and 13 weeks PI, respectively. Importantly, cSiO2 also induced AAbs to AAgs associated with rheumatoid arthritis (collagen II, fibrinogen IV, fibrinogen S, fibronectin, and vimentin), Sjögren's syndrome (α-fodrin), systemic sclerosis (topoisomerase I), vasculitis (MPO and PR3), myositis (Mi-2, TIF1-γ, MDA5), autoimmune hepatitis (LC-1), and celiac disease (TTG). cSiO2 elicited comparable but more modest IgA AAb responses in BALF and plasma. cSiO2-induced AAb production was strongly associated with time dependent inflammatory/autoimmune gene expression, ELS development, and glomerulonephritis. AAb responses were dose-dependently suppressed by DHA supplementation and negatively correlated with the ω-3 index, an erythrocyte biomarker of ω-3 content in tissue phospholipids. Taken together, these findings suggest that cSiO2 exposure elicits a diverse multi-isotype repertoire of AAbs, many of which have been reported in individuals with lupus and other autoimmune diseases. Furthermore, induction of this broad AAb spectrum could be impeded by increasing ω-3 tissue content via dietary DHA supplementation.

Silica-related diseases in the modern world

Silicosis is an ancient and potentially fatal pneumoconiosis caused by exposure to respirable crystalline silica. Silicosis is historically a disease of miners; however, failure to recognize and control the risk associated with silica exposure in contemporary work practices such as sandblasting denim jeans and manufacturing of artificial stone benchtops has led to re-emergence of silicosis around the world. This review outlines the mineralogy, epidemiology, clinical and radiological features of the various forms of silicosis and other silica-associated diseases. Perspective is provided on the most recent studies shedding light on pathogenesis, including the central role of innate immune effector cells and subsequent inflammatory cascades in propagating pulmonary fibrosis and the extrapulmonary manifestations, which uniquely characterize this pneumoconiosis. Clinical conundrums in differential diagnosis, particularly between silicosis and sarcoidosis, are highlighted, as is the importance of obtaining a careful occupational history in the patient presenting with pulmonary infiltrates and/or fibrosis. While silicosis is a completely preventable disease, unfortunately workers around the world continue to be affected and experience progressive or even fatal disease. Although no treatments have been proven, opportunities to intervene to prevent progressive disease, founded in a thorough cellular and molecular understanding of the immunopathology of silicosis, are highlighted.

The Contribution of Genetics and Epigenetics to Our Understanding of Health Disparities in Rheumatic Diseases

Socioeconomic determinants of health are associated with worse outcomes in the rheumatic diseases and contribute significantly to health disparities. However, genetic and epigenetic risk factors may affect different populations disproportionally and further exacerbate health disparities. We discuss the role of genetics and epigenetics to the health disparities observed in rheumatic diseases. We review concepts of population genetics and natural selection, current genome-wide genetic and epigenetic studies of several autoimmune diseases, and environmental exposures associated with disease risk in different populations. To understand how genomics influence health disparities in the rheumatic diseases, further studies in different populations worldwide are needed.

Health-Related Quality of Life Improvements in Systemic Lupus Erythematosus Derived from a Digital Therapeutic Plus Tele-Health Coaching Intervention: Randomized Controlled Pilot Trial

BACKGROUND

Systemic lupus erythematosus (SLE), a systemic autoimmune disease with no known cure, remains poorly understood and patients suffer from many gaps in care. Recent work has suggested that dietary and other lifestyle factors play an important role in triggering and propagating SLE in some susceptible individuals. However, the magnitude of influence of these triggers, how to identify pertinent triggers in individual patients, and whether removing these triggers confers clinical benefit is unknown.

OBJECTIVE

To demonstrate that a digital therapeutic intervention, utilizing a mobile app that allows self-tracking of dietary, environmental, and lifestyle triggers, paired with telehealth coaching, added to usual care, improves quality of life in patients with SLE compared with usual care alone.

METHODS

In this randomized controlled pilot study, adults with SLE were assigned to a 16-week digital therapeutic intervention plus usual care or usual care alone. Primary outcome measures were changes from baseline to 16 weeks on 3 validated health-related quality of life (HRQoL) tools: Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F), Brief Pain Inventory-Short Form (BPI-SF), and Lupus Quality of Life (LupusQoL).

RESULTS

A total of 50 patients were randomized (23 control, 27 intervention). In per-protocol analysis, the intervention group achieved significantly greater improvement than the control group in 9 of 11 domains: FACIT-F (34% absolute improvement for the intervention group vs -1% for the control group, P<.001), BPI-SF-Pain Interference (25% vs 0%, P=.02), LupusQoL-Planning (17% vs 0%, P=.004), LupusQoL-Pain (13% vs 0%, P=.004), LupusQoL-Emotional Health (21% vs 4%, P=.02), and LupusQoL-Fatigue (38% vs 13%, P<.001) were significant when controlling for multiple comparisons; BPI-SF-Pain Severity (13% vs -6%, P=.049), LupusQoL-Physical Health (17% vs 3%, P=.049), and LupusQoL-Burden to Others (33% vs 4%, P=.04) were significant at an unadjusted 5% significance level.

CONCLUSIONS

A digital therapeutic intervention that pairs self-tracking with telehealth coaching to identify and remove dietary, environmental, and lifestyle symptom triggers resulted in statistically significant, clinically meaningful improvements in HRQoL when added to usual care in patients with SLE.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03426384; https://clinicaltrials.gov/ct2/show/NCT03426384.

Mechanisms of Environment-Induced Autoimmunity

Although numerous environmental exposures have been suggested as triggers for preclinical autoimmunity, only a few have been confidently linked to autoimmune diseases. For disease-associated exposures, the lung is a common site where chronic exposure results in cellular toxicity, tissue damage, inflammation, and fibrosis. These features are exacerbated by exposures to particulate material, which hampers clearance and degradation, thus facilitating persistent inflammation. Coincident with exposure and resulting pathological processes is the posttranslational modification of self-antigens, which, in concert with the formation of tertiary lymphoid structures containing abundant B cells, is thought to promote the generation of autoantibodies that in some instances demonstrate major histocompatibility complex restriction. Under appropriate gene-environment interactions, these responses can have diagnostic specificity. Greater insight into the molecular and cellular requirements governing this process, especially those that distinguish preclinical autoimmunity from clinical autoimmunedisease, may facilitate determination of the significance of environmental exposures in human autoimmune disease.

Cytokine genes multi-locus analysis reveals synergistic influence on genetic susceptibility in Indian SLE - A multifactor-dimensionality reduction approach

Systemic lupus erythematosus (SLE) is a prototype autoimmune disease with unclear etiology. Several loci associated with genetic susceptibility for lupus have been described. However, it lacks reports on cytokine gene-gene interactions among SLE patients from Asian population. Epistasis interaction among single nucleotide polymorphisms (SNPs) of cytokine genes in Indian SLE patients was tested using multifactor-dimensionality reduction (MDR) analysis. A total of fourteen SNPs lacking linkage disequilibrium among different cytokines genes were genotyped in a cohort of 200 SLE patients and 201 healthy individuals as controls of Indian origin. A high degree of synergism among Lymphotoxin-α (LT-α), Interleukin-1β (IL-1β) and Interleukin-10 (IL-10) gene polymorphisms was detected in our SLE patients. Furthermore, by virtue of biological inter-relations among different cytokines, a high strength of interactions was observed among pro-inflammatory (IL-1β, IL-6) and anti-inflammatory (IL-10) cytokine gene SNPs. Also, among studied pro-inflammatory cytokines and chemokines, a strong synergistic effect among Tumor Necrosis Factor-α (TNF-α), LT-α and Monocyte Chemo-attractant Protein-1 (MCP-1) SNPs was occurred. A nature of strong interaction among the candidate cytokine genes may speculate a proactive role in causing genetic susceptibility to the disease in SLE patients with Indian origin.

The impact of obesity on disease activity, damage accrual, inflammation markers and cardiovascular risk factors in systemic lupus erythematosus

BACKGROUND

We aimed to evaluate the relationships between obesity metrics including Body Mass Index (BMI), waist to height ratio (WtHR) and fat mass percentage, and disease activity, damage accrual, inflammation markers and traditional cardiovascular risk factors in SLE patients.

METHODS

A cross-sectional study was conducted on a sample of 275 patients (90.5% females; mean age 46.37±13.85 years). Disease activity was assessed with the SLE disease activity index (SLEDAI-2K), and disease-related organ damage was assessed using the SLICC/ACR damage index (SDI). Biochemical variables of lipids profile, high-sensitivity C-reactive protein (hs-CRP), homocysteine (Hcy), anti-dsDNA titers and complement components C3 and C4 serum levels were measured. Blood pressure and ankle-brachial index (ABI) were also calculated.

RESULTS

Significant differences were observed between normal-weight, overweight and obese patients in SLEDAI (2.60±2.48 vs. 2.71±2.65 vs. 3.84±3.02; P=0.004), SDI (0.76±1.10 vs. 1.09±1.24 vs. 1.57±1.54; P=0.002), hsCRP (2.15±2.93 vs. 3.24±3.63 vs. 5.30±5.63 mg/dL; P<0.001), complement C3 level (99.92±24.45 vs. 111.38±27.41 vs. 123.16±28.96 mg/dL; P<0.001), triglycerides serum levels (85.99±41.68 vs. 102.35±50.88 vs. 129.12±61.59 mg/dL; P<0.001) and systolic blood pressure (112.28±16.35 vs. 124.25±17.94 vs. 132.78±16.71 mmHg; P=0.001) after adjusting for age and sex.

CONCLUSIONS

Patients with SLE who are obese have worse disease activity and damage accrual, higher levels of inflammation markers hs-CRP and C3 complement, increased triglycerides serum levels and systolic blood pressure levels in comparison with overweight or normal weight SLE patients, supporting that optimizing weight in SLE patients should be a potential target to improve SLE outcomes.

Single-nucleotide polymorphisms influence the promoter activities of systemic lupus erythematosus-associated genes

Systemic lupus erythematosus (SLE) is a protypical autoimmune disease and genetic factors play important roles in its pathogenesis. Since present SLE susceptibility loci are mainly studied through meta-analysis of genome-wide association study, we performed promoter activity analysis to examine the biological functions of SLE-associated single-nucleotide polymorphisms (SNPs). We found at SNP positions rs1341239, rs1800795, rs1800796, rs1800872, rs1800871, rs187238, rs360719, rs8178822, rs3761549, different alleles influenced respective promoter activities in different manners, and the effects also appeared under glucocorticoid treatment. In addition, some SNPs showed strong correlations with levels of respective serum factors, but in most cases the associations were only demonstrated in SLE individuals. Our study has further disclose the functional roles of SLE-associate SNPs in SLE pathogenesis.

Prevalence and Associated Factors of Lupus in the United States: Third National Health and Nutritional Examination Survey (NHANES III)

This study aimed to examine the prevalence and associated factors of lupus among adults in the United States. This study included 20,045 participants aged 17 years and older from the Third National Health and Nutritional Examination Survey (NHANES III) from 1988 to 1994. Their lupus status was determined by survey questions in terms of a clinician's diagnosis. Demographics and laboratory test results of all participants were collected, including biochemistry, nutrition, and antibody biomarkers. Continuous variables were compared between cases with reported lupus and non-case controls by t-test, while the Chi-square test was used for categorical variables. Weighted multivariate-adjusted logistic regression models after adjustment of covariates were used to identify associated factors of lupus risk. Of 20,045 participants, 40 people who self-reported a lupus diagnosis were identified, giving a prevalence of 241 per 100,000 (n = 40; 95% confidence interval: 133–349 per 100,000). Many factors differed significantly between lupus cases and controls. Multivariate logistic regression analysis further identified previous and current smoking along with elevated serum levels of chloride, globulin, lactate dehydrogenase, uric acid, cholesterol, and lutein or zeaxanthin as risk factors; while protective factors against lupus included non-white race, obesity, elevated serum levels of bicarbonate, creatinine, total calcium, and vitamin B12, as well as elevated urinary albumin and iodine. Our nationwide data indicate that race, obesity, cigarette smoking, and certain biomarkers such as serum lutein or zeaxanthin, calcium, and cholesterol may be associated with the development or progression of lupus, although these findings need to be confirmed in further prospective investigations.

Influence of total western diet on docosahexaenoic acid suppression of silica-triggered lupus flaring in NZBWF1 mice

Lupus is a debilitating multi-organ autoimmune disease clinically typified by periods of flare and remission. Exposing lupus-prone female NZBWF1 mice to crystalline silica (cSiO2), a known human autoimmune trigger, mimics flaring by inducing interferon-related gene (IRG) expression, inflammation, ectopic lymphoid structure (ELS) development, and autoantibody production in the lung that collectively accelerate glomerulonephritis. cSiO2-triggered flaring in this model can be prevented by supplementing mouse diet with the ω-3 polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA). A limitation of previous studies was the use of purified diet that, although optimized for rodent health, does not reflect the high American intake of saturated fatty acid (SFA), ω-6 PUFAs, and total fat. To address this, we employed here a modified Total Western Diet (mTWD) emulating the 50th percentile U.S. macronutrient distribution to discern how DHA supplementation and/or SFA and ω-6 reduction influences cSiO2-triggered lupus flaring in female NZBWF1 mice. Six-week-old mice were fed isocaloric experimental diets for 2 wks, intranasally instilled with cSiO2 or saline vehicle weekly for 4 wks, and tissues assessed for lupus endpoints 11 wks following cSiO2 instillation. In mice fed basal mTWD, cSiO2 induced robust IRG expression, proinflammatory cytokine and chemokine elevation, leukocyte infiltration, ELS neogenesis, and autoantibody production in the lung, as well as early kidney nephritis onset compared to vehicle-treated mice fed mTWD. Consumption of mTWD containing DHA at the caloric equivalent to a human dose of 5 g/day dramatically suppressed induction of all lupus-associated endpoints. While decreasing SFA and ω-6 in mTWD modestly inhibited some disease markers, DHA addition to this diet was required for maximal protection against lupus development. Taken together, DHA supplementation at a translationally relevant dose was highly effective in preventing cSiO2-triggered lupus flaring in NZBWF1 mice, even against the background of a typical Western diet.

Interaction of miR-181b and IFNA1 Polymorphisms on the Risk of Systemic Lupus Erythematosus

Introduction

A previous work has discovered that chromosome 1q32 locus linked to the risk of systemic lupus erythematosus (SLE) and miR-181b located on the susceptibility site with downregulation inversely correlating to its target molecular interferon alpha 1 (IFNA1). The purpose of this study was to investigate the association of miR-181b and IFNA1 polymorphisms with IS risk.

Methods

The miR-181b rs322931, IFNA1 rs1332190, and rs10811543 were genotyped using a Multiplex SNaPshot assay. miR-181b expression levels in plasma of SLE patients and controls were analyzed using quantitative PCR.

Results

The rs322931 CT, CT/TT, and T allele exerted an increased trend of SLE risk (CT vs. CC: adjusted OR = 1.71, 95% CI 1.16-2.50, P = 0.01; CT/TT vs. CC: adjusted OR = 1.45, 95% CI 1.08-1.95, P = 0.01; T vs. C: adjusted OR = 1.38, 95% CI 1.07-1.79, P = 0.01). Combined genotypes of the rs322931 CT/TT+rs1332190 TT and the rs322931 CC+rs10811543 AG/AA also revealed an increased risk of SLE. Gene-gene interaction analysis showed that a three-locus model consisting of rs322931, rs1332190, and rs10811543 attributed an increased risk of SLE. Further genotype-phenotype analysis revealed that rs322931 CT/TT carriers displayed lower levels of miR-181b.

Conclusions

These findings indicate that the miR-181b rs322931 may be singly and jointly responsible for the etiology of SLE by altering miR-181b expression.

A Spatiotemporal Analysis of Organ-Specific Lupus Flares in Relation to Atmospheric Variables and Fine Particulate Matter Pollution

OBJECTIVE

To identify potential clusters of systemic lupus erythematosus (SLE) organ-specific flares and their relationship to fine particulate matter pollution (PM2.5), temperature, ozone concentration, resultant wind, relative humidity, and barometric pressure in the Hopkins Lupus Cohort, using spatiotemporal cluster analysis.

METHODS

A total of 1,628 patients who fulfilled the Systemic Lupus International Collaborating Clinics classification criteria for SLE and who had a home address recorded were included in the analysis. Disease activity was assessed using the Lupus Activity Index. Assessment of rash, joint involvement, serositis, and neurologic, pulmonary, renal, and hematologic activity was quantified on a 0-3 visual analog scale (VAS). An organ-specific flare was defined as an increase in VAS of ≥1 point compared to the previous visit. Spatiotemporal clusters were detected using SaTScan software. Regression models were used for cluster adjustment and included individual, county-level, and environmental variables.

RESULTS

Significant clusters unadjusted for environmental variables were identified for joint flares (P < 0.05; n = 3), rash flares (P < 0.05; n = 4), hematologic flares (P < 0.05; n = 3), neurologic flares (P < 0.05; n = 2), renal flares (P < 0.001; n = 4), serositis (P < 0.001; n = 2), and pulmonary flares (P < 0.001; n = 2). The majority of the clusters identified changed in significance, temporal extent, or spatial extent after adjustment for environmental variables.

CONCLUSION

We describe the first spatiotemporal clusters of lupus organ-specific flares. Seasonal, as well as multi-year, cluster patterns were identified, differing in extent and location for the various organ-specific flare types. Further studies focusing on each individual organ-specific flare are needed to better understand the driving forces behind these observed changes.

Retroviruses in the pathogenesis of systemic lupus erythematosus: Are they potential therapeutic targets?

The pathogenesis of systemic lupus erythematosus (SLE) is characterised by the hyper-activation of immunologic pathways related to the antiviral response. Exogenous and endogenous retroviruses, by integrating their DNA templates in the host cell genome, may epigenetically control the transcription of genes involved in the immune response. Furthermore, their nucleic acids or neo-synthesized proteins could stimulate the sensor molecules placed upstream the inflammatory cascade. Exogenous retroviruses, like human immunodeficiency virus, have been associated to SLE-like manifestations or to a fair SLE diagnosis. In addition, there is some evidence confirming a pathogenic role of human endogenous retroviruses in SLE. In line with these data, the use of antiretroviral agents could represent an attractive opportunity in the future therapeutic algorithms of this disease, but studies are still missing.

Lupus nephritis

Lupus nephritis (LN) is a form of glomerulonephritis that constitutes one of the most severe organ manifestations of the autoimmune disease systemic lupus erythematosus (SLE). Most patients with SLE who develop LN do so within 5 years of an SLE diagnosis and, in many cases, LN is the presenting manifestation resulting in the diagnosis of SLE. Understanding of the genetic and pathogenetic basis of LN has improved substantially over the past few decades. Treatment of LN usually involves immunosuppressive therapy, typically with mycophenolate mofetil or cyclophosphamide and with glucocorticoids, although these treatments are not uniformly effective. Despite increased knowledge of disease pathogenesis and improved treatment options, LN remains a substantial cause of morbidity and death among patients with SLE. Within 10 years of an initial SLE diagnosis, 5-20% of patients with LN develop end-stage kidney disease, and the multiple comorbidities associated with immunosuppressive treatment, including infections, osteoporosis and cardiovascular and reproductive effects, remain a concern. Clearly, early and accurate diagnosis of LN and prompt initiation of therapy are of vital importance to improve outcomes in patients with SLE.

Dietary patterns and risk of systemic lupus erythematosus in women

OBJECTIVE

Dietary intake is a complex exposure and a potential risk factor for systemic lupus erythematosus (SLE) due to its impact on lipid and glucose metabolism, oxidative stress, and the intestinal microbiome. We aimed to test whether a prudent dietary pattern is associated with a lower risk of SLE, and whether a Western dietary pattern is associated with a higher risk of SLE.

METHODS

We prospectively investigated two dietary patterns and SLE risk among women in the Nurses' Health Study (NHS, 1984-2014) and Nurses' Health Study II (NHSII, 1991-2015). Food frequency questionnaires were completed every four years. Congruent with prior work in NHS and NHSII, we derived two separate dietary patterns (prudent and Western) using principal component analysis within each cohort. Incident SLE was confirmed by the American College of Rheumatology's 1997 criteria. We estimated hazard ratios (HR) and 95% confidence intervals (CI) for SLE by dietary pattern quartiles using Cox models adjusted for time-varying covariates. Models were performed separately in each cohort and results were meta-analyzed. Stratified analyses tested the association of dietary patterns with anti-dsDNA positive SLE and anti-dsDNA negative SLE.

RESULTS

We confirmed 82 NHS incident SLE cases and 98 NHSII SLE cases during 3,833,054 person-years of follow-up. A higher (healthier) prudent dietary pattern score was not associated with SLE risk (meta-analyzed HRQ4 versus Q1 0.84 [95% CI 0.51, 1.38]). Women with higher (less healthy) Western dietary pattern scores did not have a significantly increased risk for SLE (meta-analyzed HRQ4 versus Q1 1.35 [95% CI 0.77, 2.35]). Results were similar after further adjustment for body mass index. Incident anti-dsDNA positive SLE and anti-dsDNA negative SLE were not associated with either dietary pattern.

CONCLUSION

We did not observe a relationship between prudent or Western dietary pattern score and risk of SLE.

Comparative United States autoimmune disease rates for 2010-2016 by sex, geographic region, and race

PURPOSE

AIDs may disproportionately impact specific racial groups, but autoimmune (AID) prevalence information by minority racial group is sparse for many AIDs. The objective of this analysis was to supplement previously published AID prevalence rates by providing information on race rate ratios (minority race populations compared to Caucasian populations) in the United States. Preliminary to estimating race rate ratios, contemporary US-specific, health care utilization-based AID prevalence rates and female-to-male ratios were estimated and compared to previously published AID prevalence rates.

METHODS

We used a large national electronic medical record database of 52 million individuals to estimate age-adjusted direct standardized rates for 22 AIDs for 2010 through 2016 by gender, race, and US census division. These were compared to previously published estimates.

RESULTS

Female-to-male ratios were comparable with published studies. Almost all observed Multiracial AID rates were significantly higher than Caucasian rates, as well as 9 of 22 AID rates observed among Native Americans and 8 of 22 AID rates estimated among African-American patients. Regional variation was noted: highest African-American systemic lupus erythematosus rates were observed in the West North Central and South Atlantic divisions, highest African-American multiple sclerosis rates in the South Atlantic and Pacific divisions, and highest Native American rheumatoid arthritis rates in the West North Central, Mountain, and Pacific divisions.

CONCLUSIONS

Substantial AID heterogeneity exists by race and by geographic area. An important research area is further exploring factors related to heterogeneity such as potential interactions between genetic susceptibility and environmental factors.

Is air pollution affecting the disease activity in patients with systemic lupus erythematosus? State of the art and a systematic literature review

OBJECTIVE

It has been documented that several major components of air pollution, including trace elements and polycyclic aromatic hydrocarbons, are associated with the prevalence of systemic lupus erythematosus (SLE). However, the impact of air pollution on the SLE disease activity is still elusive. In this paper, we review the current evidence investigating the link between air pollution, especially when measured as PM2.5, and SLE severity and activity.

METHODS

A detailed literature search was applied a priori to the Ovid MEDLINE In-Process and Other Non-Indexed Citation 1986 to present. Presented abstracts from the European League Against Rheumatism and American College of Rheumatology (ACR)/Association for Rheumatology Health Professionals (ARHP) Annual Meetings (2011-2018) were also screened.

RESULTS

Out of a total of 1354 papers retrieved from search and references list for detailed evaluation, data from 652 patients with SLE from three studies were analyzed. Two studies had an observational longitudinal design, counting for 348 patients with a follow-up of 24 months and 79 months. Retrieved studies differed for disease activity assessment and air pollution quantifications.

CONCLUSION

Current evidence suggests that variations in air pollution may influence the disease activity in patients with SLE. However, the sample size, methodological biases, and differences across the studies make further research mandatory. Understanding the increased burden of SLE and its complications, not only from a medical, but also from a socio-demographic perspective, including an exposure to pollutants, should have implications for resource allocation and access to subspecialty care.

Association Between Cigarette Smoking and Systemic Lupus Erythematosus: An Updated Multivariate Bayesian Metaanalysis

OBJECTIVE

The association between cigarette smoking and the risk of systemic lupus erythematosus (SLE) remains a matter for debate. Additionally, the effect of the change of smokers' demographics on the risk of development of SLE over time has not been formally addressed. We aimed to examine the association between cigarette smoking and the risk of SLE by performing an updated metaanalysis.

METHODS

A literature search using keywords including "lupus," "smoking," "cigarette," "environmental," "autoimmune," and "connective tissue disease" was performed in computerized databases to identify studies addressing the relationship between cigarette smoking and SLE occurrence. A Bayesian metaanalysis was conducted by computing the log-OR between current and never smokers, and between former and never smokers. The average log-OR (subsequently converted to OR) and their corresponding 95% credible intervals (CrI) were calculated. The effect of publication time, sex, and age of patients with SLE on the effect sizes was examined by multivariate metaregression.

RESULTS

Data aggregation of 12 eligible studies comprising 3234 individuals who developed SLE and 288,336 control subjects revealed a significant association between SLE occurrence and current smoking status (OR 1.54, 95% CrI 1.06-2.25), while only a non-significant trend was demonstrated between SLE occurrence and former smoking status (OR 1.39, 95% CrI 0.95-2.08). Publication time, sex, and the mean age of patients with SLE did not explain the heterogeneity of the effect sizes.

CONCLUSION

Current smoking status is associated with risk of SLE. Sex and age of patients with SLE had no significant effect on the risk of SLE over time.

Clinical and sociodemographic factors associated with lupus nephritis in Colombian patients: A cross-sectional study

INTRODUCTION

Over the past decades, incidence of SLE (Systemic Lupus Erythematosus) has increased due to early case detection and improved survival of patients. SLE presents at an earlier age and has a more severe presentation in African-American, Native American, Asian, and Hispanic populations. Worldwide, lupus nephritis (LN) is observed in 29-60% of SLE patients, it has a negative impact in renal survival and patient mortality. Several cohorts have established potential risk factors associated with lupus nephritis, such as male sex, serological markers, and some extra-renal manifestations.

OBJECTIVES

To describe sociodemographic, clinical, immunological, and environmental risk factors in Colombian SLE patients and to compare the population with and without nephritis, in order to establish risk factors and possible associations.

MATERIALS AND METHODS

A total of 1175 SLE patients participated in this study. During medical care, an interview and structured survey was conducted and later registered in a database. Sociodemographic, clinical, immunological, and environmental exposure variables were analyzed. Bivariate and multivariate analyses were performed using presence of LN as an outcome.

RESULTS

Prevalence of LN was 38.7%. Variables significantly associated with LN included being male (OR 1.98), a duration of SLE>10 years (OR 1.48), positive anti-DNA (OR 1.34), positive anti-Sm (OR 1.45), and smoking (OR 1.66). Being non-smoker was a protective factor (OR 0.52).

CONCLUSION

This study describes potential factors associated with lupus nephritis in a Latin American population. Smoking status could be a target for intervention as it is a modifiable risk factor. The association between being male and LN is observed in Latin-American populations such as presented here. Further research in other large-scale population studies and more efforts are needed to gain better insights to explicate these relationships.