Updating on the pathogenesis of systemic lupus erythematosus

Targeting the interferon pathway with sifalimumab for the treatment of systemic lupus erythematosus

Dysregulation of the type I interferon (IFN) system is associated with various immunologic diseases, such as systemic lupus erythematosus (SLE). Targeting this dysregulation presents an attractive approach for SLE therapy. Sifalimumab, a fully human immunoglobulin G1 κ monoclonal antibody that binds to and neutralizes most IFN-α subtypes, has been recently evaluated in a Phase IIb study in patients with moderate to severe SLE. Insights gained from earlier studies were used to inform design of the Phase IIb study, to provide a more comprehensive evaluation of sifalimumab. Sifalimumab demonstrated broad efficacy across composite and organ-specific end points, suggesting that targeting of IFN-α is a promising treatment option for SLE, particularly for those patients whose disease is refractory to current standard of care.

A2A adenosine receptor upregulation correlates with disease activity in patients with systemic lupus erythematosus

BACKGROUND

Adenosine is a purine nucleoside implicated in the regulation of the innate and adaptive immune systems, acting through its interaction with four cell surface receptors: A1, A2A, A2B, and A3. There is intense interest in understanding how adenosine functions in health and during disease, but surprisingly little is known about the actual role of adenosine-mediated mechanisms in systemic lupus erythematosus (SLE). With this background, the aim of the present study was to test the hypothesis that dysregulation of A1, A2A, A2B, and A3 adenosine receptors (ARs) in lymphocytes of patients with SLE may be involved in the pathogenesis of the disease and to examine the correlations between the status of the ARs and the clinical parameters of SLE.

METHODS

ARs were analyzed by performing saturation-binding assays, as well as messenger RNA and Western blot analysis, with lymphocytes of patients with SLE in comparison with healthy subjects. We tested the effect of A2AAR agonists in the nuclear factor kB (NF-kB) pathway and on the release of interferon (IFN)-α; tumor necrosis factor (TNF)-α; and interleukin (IL)-2, IL-6, IL-1β, and IL-10.

RESULTS

In lymphocytes obtained from 80 patients with SLE, A2AARs were upregulated compared with those of 80 age-matched healthy control subjects, while A1, A2B, and A3 ARs were unchanged. A2AAR density was inversely correlated with Systemic Lupus Erythematosus Disease Activity Index 2000 score disease activity through time evaluated according to disease course patterns, serositis, hypocomplementemia, and anti-double-stranded DNA positivity. A2AAR activation inhibited the NF-kB activation pathway and diminished inflammatory cytokines (IFN-α, TNF-α, IL-2, IL-6, IL-1β), but it potentiated the release of anti-inflammatory IL-10.

CONCLUSIONS

These data suggest the involvement of A2AARs in the complex pathogenetic network of SLE, acting as a modulator of the inflammatory process. It could represent a compensatory pathway to better counteract disease activity. A2AAR activation significantly reduced the release of proinflammatory cytokines while enhancing those with anti-inflammatory activity, suggesting a potential translational use of A2AAR agonists in SLE pharmacological treatment.

Interleukin (IL)-39 [IL-23p19/Epstein-Barr virus-induced 3 (Ebi3)] induces differentiation/expansion of neutrophils in lupus-prone mice

Interleukin (IL)-12 family cytokines play critical roles in autoimmune diseases. Our previous study has shown that IL-23p19 and Epstein-Barr virus-induced 3 (Ebi3) form a new IL-12 family heterodimer, IL-23p19/Ebi3, termed IL-39, and knock-down of p19 or Ebi3 reduced diseases by transferred GL7⁺ B cells in lupus-prone mice. In the present study, we explore further the possible effect of IL-39 on murine lupus. We found that IL-39 in vitro and in vivo induces differentiation and/or expansion of neutrophils. GL7⁺ B cells up-regulated neutrophils by secreting IL-39, whereas IL-39-deficient GL7⁺ B cells lost the capacity to up-regulate neutrophils in lupus-prone mice and homozygous CD19^cre (CD19-deficient) mice. Finally, we found that IL-39-induced neutrophils had a positive feedback on IL-39 expression in activated B cells by secreting B cell activation factor (BAFF). Taken together, our results suggest that IL-39 induces differentiation and/or expansion of neutrophils in lupus-prone mice.

Genetic risk and longitudinal disease activity in systemic lupus erythematosus using targeted maximum likelihood estimation

Systemic lupus erythematous (SLE) is a chronic autoimmune disease associated with genetic and environmental risk factors. However, the extent to which genetic risk is causally associated with disease activity is unknown. We utilized longitudinal targeted maximum likelihood estimation to estimate the causal association between a genetic risk score (GRS) comprised of 41 established SLE variants and clinically important disease activity as measured by the validated systemic lupus activity questionnaire (SLAQ) in a multi-ethnic cohort of 942 individuals with SLE. We did not find evidence of a clinically important SLAQ score difference (> 4.0) for individuals with a high GRS compared to those with a low GRS across nine timepoints after controlling for sex, ancestry, renal status, dialysis, disease duration, treatment, depression, smoking, and education, as well as time-dependent confounding of missing visits. Individual SNP analyses revealed that 12 of the 41 variants were significantly associated with clinically relevant changes in SLAQ scores across timepoints 8 and 9 after controlling for multiple testing. Results based on sophisticated causal modeling of longitudinal data in a large patient cohort suggest that individual SLE risk variants may influence disease activity over time. Our findings also emphasize a role for other biological or environmental factors.

Advances in the diagnosis and classification of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is the prototype of systemic autoimmune diseases. Patients with SLE display a wide spectrum of clinical and serological findings that can mislead and delay the diagnosis. Diagnostic criteria have not been developed yet, whereas several sets of classification criteria are available; however, none of them has 100% sensitivity and 100% specificity, i.e. the hallmark of diagnostic criteria. Nevertheless, classification criteria are often misused as diagnostic criteria, which may affect earliness of diagnosis and lead to more misdiagnosed cases. Areas covered: In this review, we compare old and new classification criteria, discussing their application and pinpointing their limitations in the management of patients. Moreover, we will focus on current and novel biomarkers for SLE diagnosis, highlighting their predictive value and applicability in clinical practice. Expert commentary: SLE diagnosis still represents a challenge, remaining largely based on a clinical judgment. Besides SLE diagnosis, even its classification is still challenging to date. Indeed, although classification of SLE seems to be achieved more frequently with the 2012 SLICC criteria than with the previous 1997 ACR criteria, this last-updated 2012 set might be improved. Notably, diagnostic and classification criteria should be applied to any subject in the world, and consequently they should include immunological variables validated in different populations, which is still an unmet need.

Targeted therapeutics in SLE: emerging strategies to modulate the interferon pathway

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by impaired immune tolerance, resulting in the generation of pathogenic autoantibodies and immune complexes. Although autoreactive B lymphocytes have been the first targets for biologic therapies in SLE, the importance of the innate immune system, and in particular, pathways involved in interferon (IFN) signaling, has emerged. There are now data supporting a central role for a plasmacytoid dendritic cell-derived type I IFN pathway in SLE, with a number of biologic therapeutics and small-molecule inhibitors undergoing clinical trials. Monoclonal antibodies targeting IFN-α have completed phase II clinical trials, and an antibody against the type I IFN receptor is entering a phase III trial. However, other IFNs, such as IFN gamma, and the more recently discovered type III IFNs, are also emerging as targets in SLE; and blockade of upstream components of the IFN signaling pathway may enable inhibition of more than one IFN subtype. In this review, we discuss the current understanding of IFNs in SLE, focusing on emerging therapies.

Memory Stem T Cells in Autoimmune Disease: High Frequency of Circulating CD8+ Memory Stem Cells in Acquired Aplastic Anemia

Memory stem T cells (TSCMs) constitute a long-lived, self-renewing lymphocyte population essential for the maintenance of functional immunity. Hallmarks of autoimmune disease pathogenesis are abnormal CD4(+) and CD8(+) T cell activation. We investigated the TSCM subset in 55, 34, 43, and 5 patients with acquired aplastic anemia (AA), autoimmune uveitis, systemic lupus erythematosus, and sickle cell disease, respectively, as well as in 41 age-matched healthy controls. CD8(+) TSCM frequency was significantly increased in AA compared with healthy controls. An increased CD8(+) TSCM frequency at diagnosis was associated with responsiveness to immunosuppressive therapy, and an elevated CD8(+) TSCM population after immunosuppressive therapy correlated with treatment failure or relapse in AA patients. IFN-γ and IL-2 production was significantly increased in various CD8(+) and CD4(+) T cell subsets in AA patients, including CD8(+) and CD4(+) TSCMs. CD8(+) TSCM frequency was also increased in patients with autoimmune uveitis or sickle cell disease. A positive correlation between CD4(+) and CD8(+) TSCM frequencies was found in AA, autoimmune uveitis, and systemic lupus erythematosus. Evaluation of PD-1, CD160, and CD244 expression revealed that TSCMs were less exhausted compared with other types of memory T cells. Our results suggest that the CD8(+) TSCM subset is a novel biomarker and a potential therapeutic target for AA.

Low expression of estrogen receptor β in T lymphocytes and high serum levels of anti-estrogen receptor α antibodies impact disease activity in female patients with systemic lupus erythematosus

Background

Current evidence indicates that estrogens, in particular 17β-estradiol (E2), play a crucial role in the gender bias of autoimmune diseases although the underlying molecular mechanisms have not yet been fully elucidated. Immune cells have estrogen receptors (ERs), i.e., ERα and ERβ, that play pro- and anti-inflammatory functions, respectively, and the presence of one estrogen receptor (ER) subtype over the other might change estrogen effects, promoting or dampening inflammation. In this study, we contributed to define the influences of E2 on T cells from female patients with systemic lupus erythematosus (SLE), a representative autoimmune disease characterized by a higher prevalence in women than in men (female/male ratio 9:1). Particularly, our aim was to evaluate whether alterations of ERα and ERβ expression in T cells from female SLE patients may impact lymphocyte sensitivity to E2 and anti-ERα antibody (anti-ERα Ab) stimulation interfering with cell signaling and display a direct clinical effect.

Methods

Sixty-one premenopausal female patients with SLE and 40 age-matched healthy donors were recruited. Patients were divided into two groups based on the SLE Disease Activity Index 2000 (SLEDAI-2K) (i.e., <6 and ≥6). ER expression was evaluated in T lymphocytes by flow cytometry, immunofluorescence, and Western blot analyses. Serum anti-ERα Ab levels were analyzed by enzyme-linked immunosorbent assay (ELISA). ER-dependent signaling pathways were measured by a phosphoprotein detection kit.

Results

Intracellular ERβ expression was significantly lower in T cells from patients with SLEDAI-2K ≥6 as compared with healthy donors and patients with SLEDAI-2K <6 and negatively correlated with disease activity. The expression of intracellular and membrane-associated-ERα was similar in SLE and control T cells. ER-dependent signaling pathways were activated in T cells from SLE patients with SLEDAI-2K ≥6, but not with SLEDAI-2K <6, when both membrane and intracellular ERs were stimulated by co-treatment with E2 and anti-ERα Abs.

Conclusions

Our results demonstrate an altered ER profile in SLE patients, possibly contributing to SLE pathogenesis and interfering with clinical activity, and highlight the potential exploitation of T cell-associated ERβ as a biomarker of disease activity.

Electronic supplementary material

The online version of this article (doi:10.1186/s13293-016-0057-y) contains supplementary material, which is available to authorized users.

Autoantibodies in SLE: Specificities, Isotypes and Receptors

Systemic Lupus Erythematosus (SLE) is characterized by a wide spectrum of auto-antibodies which recognize several cellular components. The production of these self-reactive antibodies fluctuates during the course of the disease and the involvement of different antibody-secreting cell populations are considered highly relevant for the disease pathogenesis. These cells are developed and stimulated through different ways leading to the secretion of a variety of isotypes, affinities and idiotypes. Each of them has a particular mechanism of action binding to a specific antigen and recognized by distinct receptors. The effector responses triggered lead to a chronic tissue inflammation. DsDNA autoantibodies are the most studied as well as the first in being characterized for its pathogenic role in Lupus nephritis. However, others are of growing interest since they have been associated with other organ-specific damage, such as anti-NMDAR antibodies in neuropsychiatric clinical manifestations or anti-β2GP1 antibodies in vascular symptomatology. In this review, we describe the different auto-antibodies reported to be involved in SLE. How autoantibody isotypes and affinity-binding to their antigen might result in different pathogenic responses is also discussed.

Epigenetics in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease, with mechanisms that remain to be elucidated. Previous studies have proposed that genes and environments are required for lupus to develop and flare. It has been found that epigenetics have a significant influence on SLE. The present review will concentrate on epigenetics in SLE. There are a number of studies reporting that autoreactive T cells and B cells in patients with SLE have evidence of altered patterns of DNA methylation, modifications of histones and microRNA (miRNA). Long noncoding RNAs (lncRNAs) are another type of noncoding RNAs, which have an important role in epigenetics. lncRNAs may possibly become a new hotspot in SLE.

Impact of dietary deviation on disease progression and gut microbiome composition in lupus-prone SNF1 mice

Environmental factors, including microbes and diet, play a key role in initiating autoimmunity in genetically predisposed individuals. However, the influence of gut microflora in the initiation and progression of systemic lupus erythematosus (SLE) is not well understood. In this study, we have examined the impact of drinking water pH on immune response, disease incidence and gut microbiome in a spontaneous mouse model of SLE. Our results show that (SWR × NZB) F1 (SNF1 ) mice that were given acidic pH water (AW) developed nephritis at a slower pace compared to those on neutral pH water (NW). Immunological analyses revealed that the NW-recipient mice carry relatively higher levels of circulating autoantibodies against nuclear antigen (nAg) as well as plasma cells. Importantly, 16S rRNA gene-targeted sequencing revealed that the composition of gut microbiome is significantly different between NW and AW groups of mice. In addition, analysis of cytokine and transcription factor expression revealed that immune response in the gut mucosa of NW recipient mice is dominated by T helper type 17 (Th17) and Th9-associated factors. Segmented filamentous bacteria (SFB) promote a Th17 response and autoimmunity in mouse models of arthritis and multiple sclerosis. Interestingly, however, not only was SFB colonization unaffected by the pH of drinking water, but also SFB failed to cause a profound increase in Th17 response and had no significant effect on lupus incidence. Overall, these observations show that simple dietary deviations such as the pH of drinking water can influence lupus incidence and affect the composition of gut microbiome.

Autoantigen Microarray for High-throughput Autoantibody Profiling in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by the production of autoantibodies to a broad range of self-antigens. Profiling the autoantibody repertoire using array-based technology has emerged as a powerful tool for the identification of biomarkers in SLE and other autoimmune diseases. Proteomic microarray has the capacity to hold large number of self-antigens on a solid surface and serve as a high-throughput screening method for the determination of autoantibody specificities. The autoantigen arrays carrying a wide variety of self-antigens, such as cell nuclear components (nucleic acids and associated proteins), cytoplasmic proteins, phospholipid proteins, cell matrix proteins, mucosal/secreted proteins, glomeruli, and other tissue-specific proteins, have been used for screening of autoantibody specificities associated with different manifestations of SLE. Arrays containing synthetic peptides and molecular modified proteins are also being utilized for identification of autoantibodies targeting to special antigenic epitopes. Different isotypes of autoantibodies, including IgG, IgM, IgA, and IgE, as well as other Ig subtypes, can be detected simultaneously with multi-color labeled secondary antibodies. Serum and plasma are the most common biologic materials for autoantibody detection, but other body fluids such as cerebrospinal fluid, synovial fluid, and saliva can also be a source of autoantibody detection. Proteomic microarray as a multiplexed high-throughput screening platform is playing an increasingly-important role in autoantibody diagnostics. In this article, we highlight the use of autoantigen microarrays for autoantibody exploration in SLE.

Au-ACRAMTU-PEt3 Alters Redox Balance To Inhibit T Cell Proliferation and Function

Although T cells play a critical role in protection from viruses, bacteria, and tumors, they also cause autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. Unwanted T cell responses during organ transplant, graft-versus-host disease, and allergies are also major clinical problems. Although drugs are available to suppress unwanted immune responses, they have limited efficacy with serious side effects. Thus, new therapeutics limiting T cell activation, proliferation, and function can make an immediate clinical impact. To identify new suppressors of lymphocyte activation, proliferation, and function, we examined the immunosuppressive activity of gold(I) analogs of platinum-acridine antitumor agents. We found that the gold complex Au-ACRAMTU-PEt3 is a potent suppressor of murine and human T cell activation. Preincubation with Au-ACRAMTU-PEt3 suppresses the proliferation of CD4(+) and CD8(+) T cells at a similar concentration as pharmaceutical grade cyclosporine A. Au-ACRAMTU-PEt3 pretreatment decreases the production of IFN-γ, TNF-α, IL-2, and IL-17 by human and murine CD4(+) and CD8(+) T cells. When mice were treated with Au-ACRAMTU-PEt3 during viral infection, the expansion of virus-specific CD8(+) T cells was decreased 10-fold and viral load was elevated. Taken together, these results demonstrate that Au-ACRAMTU-PEt3 has potent immunosuppressive activity that could be used to suppress immune responses during transplantation and autoimmunity.

Modulation of inflammation by autophagy: Consequences for human disease

Autophagy and inflammation are 2 fundamental biological processes involved in both physiological and pathological conditions. Through its crucial role in maintaining cellular homeostasis, autophagy is involved in modulation of cell metabolism, cell survival, and host defense. Defective autophagy is associated with pathological conditions such as cancer, autoimmune disease, neurodegenerative disease, and senescence. Inflammation represents a crucial line of defense against microorganisms and other pathogens, and there is increasing evidence that autophagy has important effects on the induction and modulation of the inflammatory reaction; understanding the balance between these 2 processes may point to important possibilities for therapeutic targeting. This review focuses on the crosstalk between autophagy and inflammation as an emerging field with major implications for understanding the host defense on the one hand, and for the pathogenesis and treatment of immune-mediated diseases on the other hand.

Genetics and novel aspects of therapies in systemic lupus erythematosus

Autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and inflammatory bowel disease, have complex pathogeneses and the factors which cause these disorders are not well understood. But all have in common that they arise from a dysfunction of the immune system, interpreting self components as foreign antigens. Systemic lupus erythematosus (SLE) is one of these complex inflammatory disorders that mainly affects women and can lead to inflammation and severe damage of virtually any tissue and organ. Recently, the application of advanced techniques of genome-wide scanning revealed more genetic information about SLE than previously possible. These case-control or family-based studies have provided evidence that SLE susceptibility is based (with a few exceptions) on an individual accumulation of various risk alleles triggered by environmental factors and also help to explain the discrepancies in SLE susceptibility between different populations or ethnicities. Moreover, during the past years new therapies (autologous stem cell transplantation, B cell depletion) and improved conventional treatment options (corticosteroids, traditional and new immune-suppressants like mycophenolate mofetile) changed the perspective in SLE therapeutic approaches. Thus, this article reviews genetic aspects of this autoimmune disease, summarizes clinical aspects of SLE and provides a general overview of conventional and new therapeutic approaches in SLE.

Gender bias in lupus: does immune response initiated in the gut mucosa have a role?

The risk of developing systemic lupus erythematosus (SLE) is approximately nine times higher among women compared to men. However, very little is understood concerning the underlying mechanisms that contribute to this gender bias. Further, whether there is a link between immune response initiated in the gut mucosa, the progression of SLE and the associated gender bias has never been investigated. In this report, we show a potential link between the immune response of the gut mucosa and SLE and the gender bias of lupus for the first time, to our knowledge. Both plasma cell- and gut-imprinted- α4β7 T cell frequencies were significantly higher in the spleen and gut mucosa of female (SWR × NZB)F1 (SNF1 ) mice compared to that of their male counterparts. Importantly, female SNF1 mice not only showed profoundly higher CD45(+) immune cell densities, but also carried large numbers of interleukin (IL)-17-, IL-22- and IL-9-producing cells in the lamina propria (LP) compared to their male counterparts. Intestinal mucosa of female SNF1 mice expressed higher levels of a large array of proinflammatory molecules, including type 1 interferons and Toll-like receptors 7 and 8 (TLR-7 and TLR-8), even before puberty. Our work, therefore, indicates that the gut immune system may play a role in the initiation and progression of disease in SLE and the associated gender bias.

Clinical applications of the indirect immunofluorescence assay for detection of anticell membrane-associated DNA antibodies in juvenile systemic lupus erythematosus

BACKGROUND

Juvenile-onset systemic lupus erythematosus (JSLE) has a higher mortality risk compared to adult-onset SLE. We compared the diagnostic value of anti-cmDNA antibodies with that of antinucleosome antibodies (AnuA), anti-Sm antibodies, and anti-dsDNA antibodies and human B lymphocyte Raji cells with that of human promyelocytic leukemia HL60 cells as substrates in an indirect immunofluorescence assay to detect anti-cmDNA antibodies in JSLE patients.

METHODS

We recruited 92 JSLE patients and 71 patients with other juvenile-onset rheumatic diseases. Anti-cmDNA antibodies and antinuclear antibodies (ANA) were detected in patient sera using indirect immunofluorescence assays. Anti-dsDNA antibodies were detected by combining ELISA and indirect immunofluorescence. Anti-Sm antibodies were detected by double immunodiffusion assay and immunoblotting, while AnuA were detected by ELISA.

RESULTS

The JSLE group had a significantly higher percentage of patients positive for anti-cmDNA compared to patients with other rheumatoid diseases. Using one antibody for diagnosis, anti-cm DNA antibodies had the highest accuracy at 84.0%; using two antibodies, the combination of anti-cm DNA and anti-dsDNA antibodies had 90.8% accuracy. Raji cells used as substrate demonstrated a stronger intensity of fluorescent patterns compared to HL60 cells.

CONCLUSION

The high sensitivity, specificity, and accuracy of detection of anti-cmDNA antibodies make it a valuable diagnostic tool for JSLE.

Autoantibodies specific to D4GDI modulate Rho GTPase mediated cytoskeleton remodeling and induce autophagy in T lymphocytes

T lymphocytes from patients with Systemic Lupus Erythematosus (SLE) display multiple abnormalities, including increased cell activation, abnormal cell death by apoptosis and impairment of autophagy pathway. In the present study we report the presence of specific antibodies to D4GDI, a small GTPase family inhibitor, in a significant percentage (46%) of SLE patient sera. We also found a significant association between the presence of these autoantibodies and hematologic manifestations occurring in these patients. Investigating the possible implication of anti-D4GDI autoantibodies in SLE pathogenesis or progression, we found that these antibodies were capable of binding D4GDI expressed at the lymphocyte surface and triggering a series of subcellular events, including Rho GTPase activation. These antibodies were also able to induce autophagy in T cells from both healthy donors and SLE patients, but only those negative to these antibodies. We can conclude that anti-D4GDI autoantibodies could be capable of triggering important responses in T cells such as cytoskeleton remodeling and autophagy pathway and that, in SLE patients, the chronic exposure to these specific autoantibodies could lead to the selection of autophagy-resistant T cell clones contributing to the pathogenesis of the disease.

Optimal management of fatigue in patients with systemic lupus erythematosus: a systematic review

Among the host of distressing pathophysiological and psychosocial symptoms, fatigue is the most prevalent complaint in patients with systemic lupus erythematosus (SLE). This review is to update the current findings on non-pharmacological, pharmacological, and modality strategies to manage fatigue in patients with SLE and to provide some recommendations on optimal management of fatigue based on the best available evidence. We performed a systematic literature search of the PubMed and Scopus databases to identify publications on fatigue management in patients with SLE. Based on the studies reported in the literature, we identified nine intervention strategies that have the potential to alleviate fatigue in patients with SLE. Of the nine strategies, aerobic exercise and belimumab seem to have the strongest evidence of treatment efficacy. N-acetylcysteine and ultraviolet-A1 phototherapy demonstrated low-to-moderate levels of evidence. Psychosocial interventions, dietary manipulation (low calorie or glycemic index diet) aiming for weight loss, vitamin D supplementation, and acupuncture all had weak evidence. Dehydroepiandrosterone is not recommended due to a lack of evidence for its efficacy. In addition to taking treatment efficacy and side effects into consideration, clinicians should consider factors such as cost of treatment, commitments, and burden to the patient when selecting fatigue management strategies for patients with SLE. Any comorbidities, such as psychological distress, chronic pain, sleep disturbance, obesity, or hypovitaminosis D, associated with fatigue should be addressed.

Autoantibodies to estrogen receptors and their involvement in autoimmune diseases and cancer

The involvement of estrogens, which influence many physiologic processes, has been shown in the development or progression of several diseases including some cancers, most notably breast cancer, and autoimmune disorders. Estrogenic signal is transferred via estrogen receptors (ER) which have dual localization, predominantly intracellular but also in plasma membrane. The discovery of membrane-associated ER (mER) has greatly expanded our understanding of estrogen action; upon ligand binding, mER rapidly activate different signaling pathways inducing downstream transcription factors. Some target genes of the mER pathway may be activated independently of the intracellular ER. Additionally, intracellular ER action can be modulated by mER-initiated signaling. Most notably, the identification of autoantibodies reacting with ER (ERAB) and their possible pathogenic role in autoimmunity and cancer have opened a new path for the research in the estrogen-related receptor activity. In this review, we briefly recapitulate the localization and function of ER and mostly discuss the possible role of ERAB as novel potential prognostic and/or predictive tools in autoimmunity and cancer.

T cell receptor-associated protein tyrosine kinases: the dynamics of tolerance regulation by phosphorylation and its role in systemic lupus erythematosus

There are different abnormalities that lead to the autoreactive phenotype in T cells from systemic lupus erythematosus (SLE) patients. Proximal signaling, involving the T-cell receptor (TCR) and its associated protein tyrosine kinases (PTKs), is significantly affected in SLE. This ultimately leads to aberrant responses, which include enhanced tyrosine phosphorylation and calcium release, as well as decreased IL-2 secretion. Lck, ZAP70 and Syk, which are PTKs with a major role in proximal signaling, all present abnormal functioning that contributes to an altered T cell response in these patients. A number of other molecules, especially regulatory proteins, are also involved. This review will focus on the PTKs that participate in proximal signaling, with specific emphasis on their relevance in maintaining peripheral tolerance, their abnormalities in SLE and how these contribute to an altered T cell response.

Pathogenesis and potential therapeutic targets in systemic lupus erythematosus: from bench to bedside

Systemic lupus erythematosus (SLE) is considered an autoimmune disease with multiorgan involvement. Many advances have been made during the last decade regarding inflammatory pathways, genetic and epigenetic alterations, adaptive and innate immune system mechanisms specifically involved in SLE pathogenesis. Apoptosis has been proposed as an important player in SLE pathogenesis more than a decade ago. However, only recently new key apoptotic pathways have been investigated and the link between apoptotic debris containing autoantigens, innate immunity and ongoing inflammation has been further elucidated. Better understanding of cellular mechanisms and involved cytokines contributed to the development of new biological drugs specifically addressed for SLE therapy.

The spectrum of anti-chromatin/nucleosome autoantibodies: independent and interdependent biomarkers of disease

Autoantibodies directed to chromatin components date back to the discovery of the LE cell and the LE cell phenomenon circa 1950, and subsequent evidence that major components of that reaction were chromatin components and histones in particular. Over time, immunoassays ranging from ELISA and line immunoassays to more modern bead-based assays incorporated histone and DNA mixtures, purified histones, and purified nucleosomes leading to a more thorough understanding of the genesis and pathogenetic relationships of antibodies to chromatin components in systemic lupus erythematosus and other autoimmune conditions. More recently, interest has focussed on other components of chromatin such as high mobility group (HMG) proteins both as targets of B cell responses and pro-inflammatory mediators. This review will focus on immunoassays that utilize chromatin components, their clinical relationships, and newer evidence implicating HMG proteins and DNA neutrophil extracellular traps (NETs) as important players in systemic autoimmune rheumatic diseases.

Serology of Lupus Erythematosus: Correlation between Immunopathological Features and Clinical Aspects

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by the aberrant production of a broad and heterogenous group of autoantibodies. Even though the presence of autoantibodies in SLE has been known, for more than 60 years, still nowadays a great effort is being made to understand the pathogenetic, diagnostic, and prognostic meaning of such autoantibodies. Antibodies to ds-DNA are useful for the diagnosis of SLE, to monitor the disease activity, and correlate with renal and central nervous involvements. Anti-Sm antibodies are highly specific for SLE. Anti-nucleosome antibodies are an excellent marker for SLE and good predictors of flares in quiescent lupus. Anti-histone antibodies characterize drug-induced lupus, while anti-SSA/Ro and anti-SSB/La antibodies are associated with neonatal lupus erythematosus and photosensitivity. Anti-ribosomal P antibodies play a role in neuropsychiatric lupus, but their association with clinical manifestations is still unclear. Anti-phospholipid antibodies are associated with the anti-phospholipid syndrome, cerebral vascular disease, and neuropsychiatric lupus. Anti-C1q antibodies amplify glomerular injury, and the elevation of their titers may predict renal flares. Anti-RNP antibodies are a marker of Sharp's syndrome but can be found in SLE as well. Anti-PCNA antibodies are present in 5–10% of SLE patients especially those with arthritis and hypocomplementemia.

Autoantibody induction and adipokine levels in patients with psoriasis treated with infliximab

This study was aimed to analyse the prevalence of antinuclear antibodies in patients with psoriasis after treatment with infliximab and correlates the development of antibodies with both response to treatment and adipokines levels. Serum levels of ANA, anti-dsDNA, anti-histone, anti-nucleosome and anti-ENA antibodies at baseline after 2 and 12 months of treatment with infliximab were measured in 27 patients with psoriasis, as well as in 27 matched controls. Serum C-reactive protein (CRP), chemerin, visfatin and resistin were also assessed. The prevalence of ANA increased from 22 to 37% and 63% (p < 0.01) during treatment with infliximab, with a gradual progressive increase both in ANA titre and in percentage of ANA pattern. The prevalence of other antibodies also increased from 7 to 30% and 48% (p < 0.01) for anti-ds-DNA and from 7 to 26% and 37% for anti-nucleosome antibodies (p < 0.05), whereas the prevalence of anti-histone and anti-ENA antibodies was unchanged throughout the study period. Basal chemerin, resistin and CRP levels were higher in patients than in controls, and their levels progressively normalized during treatment (p < 0.01). Conversely, visfatin levels gradually increased (p < 0.01). ANA+ patients tended to show a faster decrease in PASI score, CRP and chemerin levels after 2 months, but the PASI score did not differ between ANA+ and ANA- patients at 12 months. A higher increase of visfatin was also found in ANA+ patients at 2 and 12 months. The antinuclear antibody response induced by infliximab was restricted to ANA, anti-dsDNA and anti-nucleosome antibodies. Patients who developed ANA positivity showed a faster clinical, inflammatory and immunological response to infliximab therapy.

Genetic variations in Toll-like receptors (TLRs 3/7/8) are associated with systemic lupus erythematosus in a Taiwanese population

Toll-like receptors (TLRs), as innate immunity sensors, play critical roles in immune responses. Six SNPs of TLR3, TLR7, and TLR8 were genotyped to determine their associations with systemic lupus erythematosus (SLE) and clinical manifestations of SLE. TLR7 SNP rs3853839 was independently associated with SLE susceptibility in females (G vs. C: p = 0.0051). TLR7 rs3853839-G (G vs. C: p = 0.0100) and TLR8 rs3764880-G (recessive model: p = 0.0173; additive model: p = 0.0161) were associated with pericardial effusion in females relative to healthy females. Anti-SSA positive cases were more likely to have the dominant TLR7 rs179010-T allele than normal controls (p = 0.0435). TLR3 rs3775296-T was associated with photosensitivity (p = 0.0020) and anemia (p = 0.0082). The “G-G” haplotype of TLR7 rs3853839 and TLR8 rs3764880 increased risk of SLE in females (age adjusted p = 0.0032). These findings suggest that TLR variations that modify gene expression affect risk for SLE susceptibility, clinical phenotype development, and production of autoantibodies.

Is there a cure for systemic lupus erythematosus?

The morbidity and mortality of systemic lupus erythematosus (SLE) is a subject of intense relevance in the literature, yet descriptions of prolonged and sustained remissions or even cure are barely reported. In recent decades the life expectancy in SLE patients has improved, but the quality of life seems to be poor compared with other chronic diseases and with the general population. The immunopathogenesis of SLE is complex and not fully understood, so patients have been treated with nonspecific immunosuppressive therapies. But in recent years, because of advances in basic science, targeted therapies have been developed. Despite the progress made in treating SLE, currently a cure in SLE seems to be a myth. SLE it seems, remains incurable. A specific treatment has not emerged to directly abrogate a disease-specific autoimmune response. Relapsing manifestations and complications of treatment still remain important markers of morbidity.

Influence of Atg5 mutation in SLE depends on functional IL-10 genotype

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.

Children and adolescents with SLE: not just little adults

Juvenile-onset systemic lupus erythematosus (JSLE) represents 15–20% of all SLE cases. Whilst features of this chronic complex multisystem autoimmune disorder are highly variable, children and adolescents generally present with a more severe illness than adults and accrue greater disease damage over time. JSLE has a less striking female preponderance and differs from the adult form in pattern of major organ manifestations. Corticosteroids are used in almost all children with JSLE along with the majority requiring additional immunosuppressive medications. Making the diagnosis early and optimizing disease control are essential to ensure that normal childhood and adolescent development is not impeded. In this young population, special consideration must be given to the long-term sequelae of the disease and treatment-related toxicity. There is a current lack of paediatric-specific controlled trials and treatment strategies are generally guided by adult data. The enormous psychological and social impact of the disease and its treatments upon the child or young person and their family necessitates a comprehensive, holistic, specialized multidisciplinary approach to managing JSLE.

Recent insights into the role of the PD-1/PD-L1 pathway in immunological tolerance and autoimmunity

Autoimmune diseases represent a heterogeneous group of conditions whose incidence is increasing worldwide. This has stimulated studies on their etiopathogenesis, derived from a complex interaction between genetic and environmental factors, in order to improve prevention and treatment of these disorders. The relevance of T regulatory cells and of the PD-1/PD-L1 pathway in controlling immune responses has been highlighted. Recent studies have in particular elucidated the putative role of the PD-1/PD-L1 pathway in regulating T cell responses and its effects on immunological tolerance and immune-mediated tissue damage. The role of the PD-1/PD-L1 pathway in autoimmunity has been already investigated in vivo in several experimental animal models including insulin-dependent diabetes mellitus, systemic lupus erythematosus, myocarditis, encephalomyelitis, rheumatoid arthritis and inflammatory bowel diseases. With the advent of candidate gene and genome-wide association studies, single nucleotide polymorphisms (SNPs) in PD-1 gene in humans have demonstrated relevant associations with a higher risk of developing autoimmune diseases in certain ethnic groups. In this review we present recent insights into the role of the PD-1/PD-L1 pathway in regulating lymphocyte activation, promotion of T regulatory cell development and function, breakdown of tolerance and development of autoimmunity. We finally speculate on the possible development of novel therapeutic treatments in human autoimmunity by modulating the PD-1/PD-L1 pathway.

TLR-9 promoter polymorphisms (T-1237C and T-1486C) are not associated with systemic lupus erythematosus: a case control study and meta-analysis

Toll like receptors (TLRs) are essential molecules implicated in both innate and adaptive immune response. Polymorphisms in TLR gene have been associated with various infectious diseases and autoimmune disorders. Role of TLR9 has been elegantly demonstrated in both human systemic lupus erythematosus (SLE) and mice model of lupus. In the present study we investigated association of TLR-9 promoter polymorphisms (T-1237C and T-1486C) with susceptibility/resistance to SLE in an Eastern Indian state which is endemic to parasitic diseases. 210 Female SLE patients who fulfilled the American College of Rheumatology criteria were enrolled along with matched healthy controls from Odisha, India. TLR-9 polymorphisms (T-1237C and T-1486C) were typed by polymerase chain reaction followed by restriction fragment length polymorphism. For meta-analysis, relevant literatures were searched from PubMed database and comprehensive meta-analysis V2 software was employed for analysis. Allele and genotype frequency of TLR-9 promoter polymorphisms (T-1237C and T-1486C) were comparable among SLE patients and controls. Further, meta-analysis of earlier reports and present study did not reveal a significant association of TLR-9 (T-1237C and T-1486C) polymorphisms with SLE. Data from the present study suggest that TLR-9 promoter polymorphisms are not associated with susceptibility to SLE in an area endemic to parasitic diseases.

4-Hydroxy-2-nonenal modified histone-H2A: a possible antigenic stimulus for systemic lupus erythematosus autoantibodies

Protein modifications by 4-hydroxy-2-nonenals (HNE) are involved in various diseases. Histones are DNA protective nucleoprotein, which adopt different structures under oxidative stress. This study was undertaken to test the role of HNE-modified-histone-H2A (HNE-H2A) in systemic lupus erythematosus (SLE). Our data revealed that HNE-mediated-lipid peroxidation in histone-H2A caused alteration in histidine, lysine and cystein residues. In addition, protein carbonyl contents were also high in HNE-H2A. HNE-specific quencher, L-carnosine further reiterates HNE-modifications. Specificity of autoantibodies from SLE patients (n=48) were analyzed towards HNE-H2A and their results were compared with sex- and age-matched controls (n=36). SLE autoantibodies show preferential binding to HNE-H2A in comparison with histone-H2A (p<0.0001). Furthermore, HNE-H2A was also detected in SLE peripheral blood mononuclear cells. In conclusion, this is the first study to demonstrate the role of HNE-modified-histone in SLE. Preferential binding of HNE-H2A by affinity purified SLE-IgG pointed out the likely role of HNE-H2A in the initiation/progression of SLE.

Up-regulation of transcription factor Blimp1 in systemic lupus erythematosus

PURPOSE

B lymphocyte induced maturation protein 1 (Blimp1) is a transcription factor that is critical for differentiation and antibody production in plasma cells. In order to understand the mechanism of systemic lupus erythematosus (SLE), the role of Blimp1 expression was studied in patients with SLE and in healthy control subjects. And Blimp1 tissue distribution in MRL/lpr lupus mice was also investigated.

METHODS

The mRNA expression level of Blimp1 was analyzed by fluorescent real time PCR and compared between the 40 SLE patients and 30 control subjects. Expression of CD138, CD27 and CD19 in peripheral blood cells was analyzed by flow cytometry. Blimp1 mRNA and protein expression levels and tissue distribution in the kidneys, spleen and lymph nodes of MRL/lpr lupus and normal mice were analyzed.

RESULTS

Blimp1 mRNA expression level was 2.1 times greater in the SLE group as compared to the control group. The increased mRNA expression of Blimp1 seemed to be related to SLE disease activity and anti-nuclear antibody (ANA) titer. In SLE patients, the CD138+ plasma cells increased as the CD27+ cells decreased. Compared with normal mice, Blimp1 was strongly expressed in the kidneys, lymph nodes and spleen of MRL/lpr lupus mice. The expression level of Blimp1 mRNA in the kidneys, lymph nodes and spleen of MRL/lpr lupus mice was much higher than normal mice (1.76, 2.02, and 2.05 times greater, respectively, P<0.05). Similarly, protein levels in the above mentioned organs were also much higher (1.54, 1.99, and 2.21 times greater, respectively, P<0.05).

CONCLUSIONS

The elevated expression of Blimp1 in SLE patients and in the lupus mouse model is correlated with increases in plasma cells, autoantibodies and disease activity. It is closely related to differentiation of B-lymphocytes, antibody production and renal lesions. Blimp1 may play a role in SLE disease development.

Biomarker profiling for lupus nephritis

Lupus nephritis (LN) is one of the most severe manifestations of systemic lupus erythematosus (SLE), which is associated with significant morbidity and mortality of SLE patients. The pathogenesis of LN involves multiple factors, including genetic predisposition, epigenetic regulation and environmental interaction. Over the last decade, omics-based techniques have been extensively utilized for biomarker screening and a wide variety of variations which are associated with SLE and LN have been identified at the levels of genomics, transcriptomics and proteomics. These studies and discoveries have expanded our understanding of the molecular basis of the disease and are important for identification of potential therapeutic targets for disease prediction and early treatment. In this review, we summarize some of the recent studies targeted at the identification of LN-associated biomarkers using genomics and proteomic approaches.

Anti-ribosomal P protein IgG autoantibodies in patients with systemic lupus erythematosus: diagnostic performance and clinical profile

BACKGROUND

This study was devised to assess the performance of anti-ribosomal P (anti-Rib-P) antibodies in the diagnosis of systemic lupus erythematosus (SLE) and the association of these antibodies with the clinical features of SLE.

METHODS

We used a fluorescence enzyme immunoassay to determine anti-Rib-P levels in an SLE group, a rheumatic disease control (RDC) group (rheumatoid arthritis (RA), ankylosing spondylitis, psoriatic arthritis and juvenile idiopathic arthritis), and a healthy control (HC) group. We also determined anti-Smith antigen (anti-Sm) and anti-double-stranded DNA (anti-dsDNA) antibody levels. Receiver operating characteristic (ROC) curves were constructed and the best cut-off points for positivity were determined. Using regression analysis, the relationship between clinical variables and autoantibody levels was analyzed.

RESULTS

In total, 127 patients with SLE, 256 controls with other rheumatic diseases, and 100 HCs were studied. Anti-Rib-P autoantibodies were positive in 18 (14.2%) of the patients with SLE (mean concentration of 30.6 ± 46.9 U/ml) and in 2 patients with RA (0.8% of the RDC group). In addition, 12 patients with SLE (9.4%) were positive for anti-Sm (31.1 ± 40.8 U/ml) and 63 (49.6%) were positive for anti-dsDNA autoantibodies (88.4 ± 88.5 U/ml). When we assessed the 18 patients with SLE who had tested positive for anti-Rib-P, we found that 4 of these were positive for anti-Rib-P only, whereas 12 were positive for anti-Rib-P plus anti-dsDNA, and 2 were positive for all three antibodies. There were no samples positive for anti-Rib-P plus anti-Sm. The specificity, sensitivity, positive likelihood ratio, and negative likelihood ratio of anti-Rib-P for SLE diagnosis were 99.4%, 14.2%, 23.7%, and 0.86%, respectively.Caucasian ethnicity was associated with lower anti-Rib-P antibody levels. No relation was found between anti-Rib-P levels and neuropsychiatric or other clinical features.

CONCLUSIONS

Anti-Rib-P autoantibodies have high specificity for SLE, and measurement of these might improve the accuracy of SLE diagnosis. In this study, we found that Caucasian ethnicity was associated with lower anti-Rib-P antibody levels.

Requirements for innate immune pathways in environmentally induced autoimmunity

There is substantial evidence that environmental triggers in combination with genetic and stochastic factors play an important role in spontaneous autoimmune disease. Although the specific environmental agents and how they promote autoimmunity remain largely unknown, in part because of diverse etiologies, environmentally induced autoimmune models can provide insights into potential mechanisms. Studies of idiopathic and environmentally induced systemic autoimmunity show that they are mediated by common adaptive immune response genes. By contrast, although the innate immune system is indispensable for autoimmunity, there are clear differences in the molecular and cellular innate components that mediate specific systemic autoimmune diseases, suggesting distinct autoimmune-promoting pathways. Some of these differences may be related to the bifurcation of toll-like receptor signaling that distinguishes interferon regulatory factor 7-mediated type I interferon production from nuclear factor-κB-driven proinflammatory cytokine expression. Accordingly, idiopathic and pristane-induced systemic autoimmunity require both type I interferon and proinflammatory cytokines whereas the less aggressive mercury-induced autoimmunity, although dependent on nucleic acid-binding toll-like receptors, does not require type I interferon but needs proinflammatory cytokines. Scavenger receptors and the inflammasome may contribute to silica-induced autoimmunity. Greater understanding of the innate mechanisms responsible for idiopathic and environmentally induced autoimmunity should yield new information into the processes that instigate and drive systemic autoimmunity.

Decrease in blood pressure and regression of cardiovascular complications by angiotensin II vaccine in mice

Vaccines have been recently developed to treat various diseases such as cancer, rheumatoid arthritis and Alzheimer’s disease in addition to infectious diseases. However, before use in the clinical setting, vaccines targeting self-antigens must be demonstrated to be effective and safe, evoking an adequate humoral immune response from B cells while avoiding T cell activation in response to self. Although the vaccine targeting angiotensin II (Ang II) is efficient in rodents and humans, little is known regarding the immunological activation and safety of the vaccine. In this study, we evaluated the efficiency and safety of an Ang II peptide vaccine in mice. Immunization with Ang II conjugated to keyhole limpet hemocyanin (KLH) successfully induced the production of anti-Ang II antibody, which blocked Ang II signaling in human aortic smooth muscle cells. However, Ang II itself did not activate T cells, as assessed by the proliferation and lymphokine production of T cells in immunized mice, whereas KLH activated T cells. In an Ang II-infused model, the non-immunized mice showed high blood pressure (BP), whereas the immunized mice (Ang II-KLH) showed a significant decrease in systolic BP, accompanied by significant reductions in cardiac hypertrophy and fibrosis. Importantly, anti-Ang II antibody titer was not elevated even after the administration of large amounts of Ang II, indicating that Ang II itself boosted antibody production, most likely due to less activation of T cells. In addition, no accumulation of inflammatory cells was observed in immunized mice, because endogenous Ang II would not activate T cells after immunization with Ang II-KLH. Taken together, these data indicate that vaccines targeting Ang II might be effective to decrease high BP and prevent cardiovascular complications without severe side effects.

Epstein–Barr virus and autoimmunity: the role of a latent viral infection in multiple sclerosis and systemic lupus erythematosus pathogenesis

Multiple sclerosis (MS) and systemic lupus erythematosus (SLE) are both chronic autoimmune diseases with unknown etiology. To date, EBV is the most closely implicated infectious agent to be associated with both MS and SLE. Epidemiological findings show a strong correlation between EBV infection and the risk of developing these diseases. The type and magnitude of both EBV-specific antibodies and T-cell responses produced by MS or SLE patients are dysregulated when compared with healthy cohorts. Despite all these findings, it is still not clear if and how EBV triggers autoimmunity. EBV infects and establishes latency mainly in B cells, but it can also infect other cell types and indirectly influence the activation status of the immune system by stimulating the production of proinflammatory mediators. This could play a role in both MS and SLE pathogenesis. In this review we will summarize recent literature that links EBV infection to SLE and MS, and discuss possible new mechanisms that explain how EBV drives autoimmunity.

Lab-on-a-chip: emerging analytical platforms for immune-mediated diseases

Miniaturization of analytical procedures has a significant impact on diagnostic testing since it provides several advantages such as: reduced sample and reagent consumption, shorter analysis time and less sample handling. Lab-on-a-chip (LoC), usually silicon, glass, or silicon-glass, or polymer disposable cartridges, which are produced using techniques inherited from the microelectronics industry, could perform and integrate the operations needed to carry out biochemical analysis through the mechanical realization of a dedicated instrument. Analytical devices based on miniaturized platforms like LoC may provide an important contribution to the diagnosis of high prevalence and rare diseases. In this paper we review some of the uses of Lab-on-a-chip in the clinical diagnostics of immune-mediated diseases and we provide an overview of how specific applications of these technologies could improve and simplify several complex diagnostic procedures.

Extent and characteristics of self-reported pain in patients with systemic lupus erythematosus

Objective:

Patients' own experiences of subjective symptoms are scarcely covered, and the objective of this study was to investigate the extent and characteristics of self-reported pain in patients with systemic lupus erythematosus (SLE).

Methods:

This study comprised a cross-sectional design where 84 patients with SLE were asked to complete self-assessments: visual analogue scale of pain and the Short-Form McGill Pain Questionnaire. Medical assessments, including ESR, SLAM, SLEDAI, and SLICC, were also performed.

Results:

Of the study population, 24% reported higher levels of SLE-related pain (≥40 mm on VAS). This group had a significantly shorter disease duration, higher ESR, and higher disease activity, according to the SLAM and SLEDAI, compared to the rest of the study population. This group mainly used the words “tender,” “aching,” and “burning” to describe moderate and severe pain, and they used a greater number of words to describe their pain. Of the patients with higher levels of pain, 70% reported their present pain as “distressing.” The most common pain location for the whole patient population was the joints. Patients rated their disease activity significantly higher than physicians did.

Conclusion:

These findings expand the current knowledge of the extent of SLE-related pain and how patients perceive this pain. The results can contribute to affirmative, supportive and caring communication and especially highlight SLE-related pain in patients with a short disease duration and high disease activity.

Novel estrogen target gene ZAS3 is overexpressed in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic, inflammatory autoimmune disease characterized by significant gender bias. Previous studies have established a role for hormones in SLE pathogenesis, including the sex hormone estrogen. Estrogen regulates gene expression by translocating estrogen receptors (ER) α and β into the nucleus where they induce transcription by binding to estrogen response elements (EREs) of target genes. The ZAS3 locus encodes a signaling and transcriptional molecule involved in regulating inflammatory responses. We show that ZAS3 is significantly up-regulated in SLE patients at both the protein and mRNA levels in peripheral blood mononuclear cells (PBMCs). Furthermore, estrogen stimulates the expression of ZAS3 in vitro in several leukocyte and breast cancer cell lines of both human and murine origin. In vivo estrogen treatment mediates induction of tissue specific ZAS3 expression in several lymphoid organs in mice. Estrogen stimulation also significantly up-regulates ZAS3 expression in primary PBMCs, while treatment with testosterone has no effect. Mechanistically, estrogen induces differential ERα binding to putative EREs within the ZAS3 gene and ERα knockdown with siRNA prevents estrogen induced ZAS3 up-regulation. In contrast, siRNA targeting IFNα has no effect. These data demonstrate that ZAS3 expression is directly regulated by estrogen and that ZAS3 is overexpressed in lupus. Since ZAS3 has been shown to regulate inflammatory pathways, its up-regulation by estrogen could play a critical role in female-biased autoimmune disorders.

Biochemical analysis of the epitope specificities of anti-C1q autoantibodies accompanying human lupus nephritis reveals them as a dynamic population in the course of the disease

We analyzed the epitope specificities of the polyclonal anti-C1q antibodies, present in human LN sera, searching to deduce the structural characteristics of C1q associated with its transition to an autoantigen. We screened 78 serum samples from LN patients distributed in three clinical groups - non-active, moderately active and severely active. We found three classes of C1q autoepitopes: (a) neo-epitopes, exposed upon immobilization due to conformational changes; (b) epitopes formed by sequences that are brought together by the conformation of the whole molecule; (c) cryptic epitopes that become exposed only after fragmentation of C1q. The latter suggest that the immunogen involved in the initiation of anti-C1q autoantibodies might be an extrinsic molecule that shares some degree of structural similarity to C1q. None of the tested epitope specificities was associated with active LN. We found a prevalence of anti-gC1q antibodies among the non-active LN patients suggesting that they might be the fraction of the polyclonal anti-C1q, preceding the initiation of autoimmunity to C1q, or alternatively, preceding LN flare.

Immunology, autoimmunity, and autoantibodies in Parkinson's disease

Recent revelations of immune alterations in Parkinson's disease have led to the convergence that an autoimmune mechanism may play a role in the etiopathogenesis of this neurodegenerative disease. In the current study, 77 Parkinson's disease patients and 77 matched healthy controls were analyzed for the presence of seven autoantibodies previously found to be associated with central nervous system manifestations namely: antineuronal-cells, anti-brain lysate, anti-dsDNA, anti-phosphatidylserine, anti-cardiolipin, anti-serotonin, and anti-melanocytes antibodies. Patients underwent systematic assessments of demographics, clinical, and biochemical manifestations. Three autoantibodies were found to be more prevalent among Parkinson's disease patients (antineuronal cells10.3% vs. 1.3%, p = 0.017; anti-brain lysate 9.1% vs. 1.3%, p = 0.032; anti-dsDNA 10.3% vs. 2.6%, p = 0.049). Clinical manifestations of Parkinson's disease, particularly dyskinesia and depression, were found to be associated with the presence of these autoantibodies.