Autoantibodies in SLE: Specificities, Isotypes and Receptors

Renin-Angiotensin System-Modifying Antihypertensive Drugs Can Reduce the Risk of Cardiovascular Complications in Lupus: A Retrospective Cohort Study

BACKGROUND

Patients with systemic lupus erythematosus have a higher incidence of cardiovascular disease than the general population. Antihypertensive drugs that modify the renin-angiotensin system (RAS) are used to protect renal function in lupus nephritis and may also have extrarenal effects that lower cardiovascular disease risk due to their anti-inflammatory properties. In this study, we compared the effects of RAS vs non-RAS antihypertensive drugs on cardiovascular disease incidence in patients with lupus.

METHODS

Using a medical insurance claims dataset, 220,168 patients with lupus were identified, of which 31,647 patients (4018 patients prescribed RAS drugs, 27,629 patients prescribed non-RAS drugs) were eligible for the study. Patients had a mean age of 46.1 years, were 93.0% female, and healthy (96.9% Charlson Comorbidity Index score 0-4). Patients in the 2 drug groups were propensity score matched using demographic data, risk factors, and comorbidities.

RESULTS

Use of RAS vs non-RAS drugs lowered the relative risk (RR) of diagnosis of cardiovascular disease (RR 0.80; 95% confidence interval [CI], 0.74-0.87), which was more pronounced after propensity score matching (RR 0.62; 95% CI, 0.57-0.68). The decreased risk in cardiovascular disease occurred regardless of lupus nephritis status (with lupus nephritis: RR 0.51; 95% CI, 0.39-0.65; without lupus nephritis: RR 0.65; 95% CI, 0.59-0.72). RAS-modifying therapies significantly increased cardiovascular disease-free survival probability over a 5-year period (86.0% vs 78.3% probability).

CONCLUSIONS

RAS-modifying drugs reduced the risk of cardiovascular disease in patients with systemic lupus erythematosus in this dataset. These findings have the potential to impact clinical decision-making with regards to hypertension management in patients with lupus.

Self-reactive IgE and anti-IgE therapy in autoimmune diseases

Growing evidence indicates the pathogenic role of autoreactive IgE in autoimmune diseases. Incidence of autoimmune and allergic diseases in the industrialized countries is consistently icreasing, thus leading to concerted efforts to comprehend the regulation of IgE-mediated mechanisms. The first reports of a presence of IgE autoantibodies in patients with autoimmune diseases have been published a long time ago, and it is now recognized that self-reactive IgE can mediate inflammatory response in bullous pemhigoid, systemic lupus erythematosus, chronic urticaria, and atopic dermatitis. The advances in understanding the pathomechanisms of these disorders brought to a successful use of anti-IgE strategies in their management. The present review discusses the current state of knowledge on the IgE-mediated autoimmunity and anti-IgE treatment, and pave the way for further exploration of the subject.

Epistatic effects of Siglec-G and DNase1 or DNase1l3 deficiencies in the development of systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a severe autoimmune disease that displays considerable heterogeneity not only in its symptoms, but also in its environmental and genetic causes. Studies in SLE patients have revealed that many genetic variants contribute to disease development. However, often its etiology remains unknown. Existing efforts to determine this etiology have focused on SLE in mouse models revealing not only that mutations in specific genes lead to SLE development, but also that epistatic effects of several gene mutations significantly amplify disease manifestation. Genome-wide association studies for SLE have identified loci involved in the two biological processes of immune complex clearance and lymphocyte signaling. Deficiency in an inhibitory receptor expressed on B lymphocytes, Siglec-G, has been shown to trigger SLE development in aging mice, as have mutations in DNA degrading DNase1 and DNase1l3, that are involved in clearance of DNA-containing immune complexes. Here, we analyze the development of SLE-like symptoms in mice deficient in either Siglecg and DNase1 or Siglecg and DNase1l3 to evaluate potential epistatic effects of these genes. We found that germinal center B cells and follicular helper T cells were increased in aging Siglecg ^-/- x Dnase1 ^-/- mice. In contrast, anti-dsDNA antibodies and anti-nuclear antibodies were strongly increased in aging Siglecg^-/- x Dnase1l3^-/- mice, when compared to single-deficient mice. Histological analysis of the kidneys revealed glomerulonephritis in both Siglecg ^-/- x Dnase1 ^-/- and Siglecg^-/- x Dnase1l3^-/- mice, but with a stronger glomerular damage in the latter. Collectively, these findings underscore the impact of the epistatic effects of Siglecg with DNase1 and Dnase1l3 on disease manifestation and highlight the potential combinatory effects of other gene mutations in SLE.

ANA-specific antibodies, ANA patterns, anti-ds-DNA results, and clinical diagnosis: a laboratory and clinical audit

The diagnosis of systemic autoimmune diseases (SAID) is challenging, due to overlapping features with other non-immune disorders. Anti-nuclear antibodies (ANA)/anti-cellular antibodies are the sensitive screening tests but anti-double-stranded-deoxyribonucleic acid-antibody (anti-ds-DNA) and ANA-specific antibodies are specific for SAID. We aimed to look at ANA-specific antibodies in our patients and correlated them with ANA patterns, anti-ds-DNA, and clinical diagnosis for proper interpretation and better patient management cost-effectively. A retrospective data analysis of 641 patients was done (1st of February 2019 to 31st of July 2021) who were tested for ANA-specific antibodies at the Immunology Department of Indus Hospital and Health Network. ANA and anti-ds-DNA results and clinical diagnosis were also analyzed for ANA-specific antibody-positive patients. Descriptive data were presented in mean ± standard deviation and frequency percentages whereas inferential data were analyzed with a chi-square test for association between ANA-specific antibodies status, ANA, anti-ds-DNA, and clinical features. ANA-specific antibodies test revealed positivity for at least one autoantibody in 245 (38.2%) patients. Of these, ANA was tested in 206 patients reactive for ANA-specific antibodies and found positive in 195 (95%) as compared to negative (< 0.001). Speckled and homogenous were predominant ANA patterns in ANA-specific antibody-positives (56% and 42% respectively). Multiple ANA patterns were found in 18 patients most commonly with systemic lupus erythematosus (SLE) and mixed connective tissue disorder (MCTD). Anti-SSA were the most common ANA-specific antibodies (50%) and were mostly found in sera with speckled (61/97) and homogenous (38/97) patterns and associated mostly with SLE (48%) and Sjogren's syndrome (86%). Among ANA-negative patients, anti-SSA were the most common antibodies (n = 5). Anti-ds-DNA was found in 66% of SLE patients along with another ANA-specific antibody. This study showed that testing for ANA-specific antibodies cannot be gated on ANA patterns. Also, there is a redundancy of these antibodies with various clinical diagnoses. Moreover, they are useful in making a diagnosis in ANA-negative patients as well with clinical suspicion.

Sex bias in lymphocytes: Implications for autoimmune diseases

Autoimmune diseases are characterized by a significant sex dimorphism, with women showing increased susceptibility to disease. This is, at least in part, due to sex-dependent differences in the immune system that are influenced by the complex interplay between sex hormones and sex chromosomes, with contribution from sociological factors, diet and gut microbiota. Sex differences are evident in the number and function of lymphocyte populations. Women mount a stronger pro-inflammatory response than males, with increased lymphocyte proliferation, activation and pro-inflammatory cytokine production, whereas men display expanded regulatory cell subsets. Ageing alters the immune landscape of men and women in differing ways, resulting in changes in autoimmune disease susceptibility. Here we review the current literature on sex differences in lymphocyte function, the factors that influence this, and the implications for autoimmune disease. We propose that improved understanding of sex bias in lymphocyte function can provide sex-specific tailoring of treatment strategies for better management of autoimmune diseases.

The anti-inflammatory effects of Hedyotis diffusa Willd on SLE with STAT3 as a key target

ETHNOPHARMACOLOGICAL RELEVANCE

Hedyotis diffusa Willd, also named Scleromitrion diffusum (Willd.) R.J. Wang, is one medical herb, which has been traditionally used by the She nationality in China. And H. diffusa represents a beneficial effect on Systemic lupus erythematosus (SLE) treatment in clinic.

AIM OF THE STUDY

The underlying mechanisms of the protective effects of H. diffusa on SLE remain unclear. In this study, we treated MRL/lpr mice with H. diffusa water extract (HDW) to assess its therapeutic effects and verified its regulating signalling pathway through cytological experiments.

MATERIALS AND METHODS

In the present study, the constituents of HDW were analysed through ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS) and SCIEX OS software. The protective activity and underlying mechanisms were studied in a MRL/lpr lupus mouse model. The blood cells, autoantibodies, metabolites and the cytokines in serum were identified with a hematology analyzer, specific ELISA kit, GC/MS system and cytometric assays. The histological and immunohistochemical analysis were engaged in the morphologic, and the expression and translocation of the crucial protein observation. The dual luciferase reporter assay was applied to identifying the regulative activity of HDW. The transcription and translation expression of the protein was studied by real-time PCR and Western blot assays. The network pharmacology analysis was employed to predict the IL-6/STAT3 pathway regulators and the screen the STAT3 inhibitors in HDW.

RESULTS

The results revealed the capability of HDW to attenuate the production of autoantibodies, secretion of inflammatory cytokines (IL-6 and IFN-γ), and suppressed the IgG and C3 deposition, the development of glomerular lesions in MRL/lpr mice. Serum metabolomics study showed the improvement in serum metabolites, especially aminoacyl-tRNA biosynthesis, by HDW. IL-6 was clarified to be highly associated with the significantly changed metabolites in network analysis. We further demonstrated the effects of HDW on the IL-6/STAT3 pathway in vivo and in vitro.

CONCLUSIONS

This study suggested that HDW exerts a therapeutic effect in SLE model mice by suppressing the IL-6/STAT3 pathway.

Establishment and analysis of a disease risk prediction model for the systemic lupus erythematosus with random forest

Systemic lupus erythematosus (SLE) is a latent, insidious autoimmune disease, and with the development of gene sequencing in recent years, our study aims to develop a gene-based predictive model to explore the identification of SLE at the genetic level. First, gene expression datasets of SLE whole blood samples were collected from the Gene Expression Omnibus (GEO) database. After the datasets were merged, they were divided into training and validation datasets in the ratio of 7:3, where the SLE samples and healthy samples of the training dataset were 334 and 71, respectively, and the SLE samples and healthy samples of the validation dataset were 143 and 30, respectively. The training dataset was used to build the disease risk prediction model, and the validation dataset was used to verify the model identification ability. We first analyzed differentially expressed genes (DEGs) and then used Lasso and random forest (RF) to screen out six key genes (OAS3, USP18, RTP4, SPATS2L, IFI27 and OAS1), which are essential to distinguish SLE from healthy samples. With six key genes incorporated and five iterations of 10-fold cross-validation performed into the RF model, we finally determined the RF model with optimal mtry. The mean values of area under the curve (AUC) and accuracy of the models were over 0.95. The validation dataset was then used to evaluate the AUC performance and our model had an AUC of 0.948. An external validation dataset (GSE99967) with an AUC of 0.810, an accuracy of 0.836, and a sensitivity of 0.921 was used to assess the model's performance. The external validation dataset (GSE185047) of all SLE patients yielded an SLE sensitivity of up to 0.954. The final high-throughput RF model had a mean value of AUC over 0.9, again showing good results. In conclusion, we identified key genetic biomarkers and successfully developed a novel disease risk prediction model for SLE that can be used as a new SLE disease risk prediction aid and contribute to the identification of SLE.

Heavy Chain Constant Region Usage in Antibodies to Peptidylarginine Deiminase 4 as a Marker of Disease Subsets in Rheumatoid Arthritis

OBJECTIVE

The study of autoantibody isotypes in autoimmune diseases is useful for identifying clinically relevant endotypes. This study was undertaken to study the prevalence and clinical significance of different isotypes and IgG subclasses of anti-peptidylarginine deiminase 4 (anti-PAD4) autoantibodies in individuals with rheumatoid arthritis (RA).

METHODS

In 196 RA subjects and 64 healthy controls, anti-PAD4 antibody types were determined using enzyme-linked immunosorbent assay. We investigated associations between anti-PAD4 antibodies and clinical outcomes, and relevant features were confirmed in an independent RA cohort.

RESULTS

Anti-PAD4 IgG1, anti-PAD4 IgG2, anti-PAD4 IgG3, anti-PAD4 IgG4, anti-PAD4 IgA, and anti-PAD4 IgE antibodies were more frequent in RA patients than healthy controls (P < 0.001). Anti-PAD4 IgG1, anti-PAD4 IgG3, and anti-PAD4 IgE were associated with distinct clinical features. Anti-PAD4 IgG1 was predictive of progressive radiographic joint damage (odds ratio [OR] 4.88, P = 0.005), especially in RA patients without baseline joint damage (40% versus 0%, P = 0.003) or in those negative for anti-cyclic citrullinated peptide and/or rheumatoid factor (OR 32; P = 0.009). IgG1 was also associated with higher levels of C-reactive protein (P = 0.006) and interleukin-6 (P = 0.021). RA patients with anti-PAD4 IgG3 had higher baseline joint damage scores (median Sharp/van der Heijde score 13 versus 7, P = 0.046), while those with anti-PAD4 IgE had higher Disease Activity Score in 28 joints (median 4.0 versus 3.5, P = 0.025), more frequent rheumatoid nodules (31% versus 16%, P = 0.025), and more frequent interstitial lung disease (ground-glass opacification) (24% versus 9%, P = 0.014). Anti-PAD4 IgG1 antibody associations with joint damage were corroborated in an independent RA cohort.

CONCLUSION

Anti-PAD4 IgG1, anti-PAD4 IgG3, and anti-PAD4 IgE antibodies identify discrete disease subsets in RA, suggesting that heavy chain usage drives distinct effector mechanisms of anti-PAD4 antibodies in RA.

Regulatory T cells and immunoglobulin E: A new therapeutic link for autoimmunity?

Autoimmune diseases have a prevalence of approximately 7 to 9% and are classified as either organ-specific diseases, including type I diabetes, multiple sclerosis, inflammatory bowel disease and myasthenia gravis, or systemic diseases, including systemic lupus erythematosus, rheumatoid arthritis and Sjögren's syndrome. While many advancements have been made in understanding of the mechanisms of autoimmune disease, including the nature of self-tolerance and its breakdown, there remain unmet needs in terms of effective and highly targeted treatments. T regulatory cells (Tregs) are key mediators of peripheral tolerance and are implicated in many autoimmune diseases, either as a result of reduced numbers or altered function. Tregs may be broadly divided into those generated in the thymus (tTregs) and those generated in the periphery (pTregs). Tregs target many different immune cell subsets and tissues to suppress excessive inflammation and to support tissue repair and homeostasis: there is a fine balance between Treg cell stability and the plasticity that is required to adjust Tregs' regulatory purposes to particular immune responses. The central role of immunoglobulin E (IgE) in allergic disease is well recognized, and it is becoming increasingly apparent that this immunoglobulin also has a wider role encompassing other diseases including autoimmune disease. Anti-IgE treatment restores the capacity of plasmacytoid dendritic cells (pDCs) impaired by IgE- high-affinity IgE receptor (FcεR1) cross-linking to induce Tregs in vitro in atopic patients. The finding that anti-IgE therapy restores Treg cell homeostasis, and that this mechanism is associated with clinical improvement in asthma and chronic spontaneous urticaria suggests that anti-IgE therapy may also have a potential role in the treatment of autoimmune diseases in which Tregs are involved.

Not all autoantibodies are clinically relevant. Classic and novel autoantibodies in Sjögren’s syndrome: A critical review

Sjögren’s syndrome (SjS) is a heterogeneous systemic disease. The abnormal responses to La/SSB and Ro/SSA of both B-cells and T-cells are implicated as well as others, in the destruction of the epithelium of the exocrine glands, whose tissue characteristically shows a peri-epithelial lymphocytic infiltration that can vary from sicca syndrome to systemic disease and lymphoma. Despite the appearance of new autoantibodies, anti-Ro/SSA is still the only autoantibody included in the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria and is used extensively as a traditional biomarker in clinical practice. The study and findings of new autoantibodies in SjS has risen in the previous decade, with a central role given to diagnosis and elucidating new aspects of SjS physiopathology, while raising the opportunity to establish clinical phenotypes with the goal of predicting long-term complications. In this paper, we critically review the classic and the novel autoantibodies in SjS, analyzing the methods employed for detection, the pathogenic role and the wide spectrum of clinical phenotypes.

A Temporal Comparative RNA Transcriptome Profile of the Annexin Gene Family in the Salivary versus Lacrimal Glands of the Sjögren's Syndrome-Susceptible C57BL/6.NOD-Aec1Aec2 Mouse

A generally accepted hypothesis for the initial activation of an immune or autoimmune response argues that alarmins are released from injured, dying and/or activated immune cells, and these products complex with receptors that activate signal transduction pathways and recruit immune cells to the site of injury where the recruited cells are stimulated to initiate immune and/or cellular repair responses. While there are multiple diverse families of alarmins such as interleukins (IL), heat-shock proteins (HSP), Toll-like receptors (TLR), plus individual molecular entities such as Galectin-3, Calreticulin, Thymosin, alpha-Defensin-1, RAGE, and Interferon-1, one phylogenetically conserved family are the Annexin proteins known to promote an extensive range of biomolecular and cellular products that can directly and indirectly regulate inflammation and immune activities. For the present report, we examined the temporal expression profiles of the 12 mammalian annexin genes (Anxa1-11 and Anxa13), applying our temporal genome-wide transcriptome analyses of ex vivo salivary and lacrimal glands from our C57BL/6.NOD-Aec1Aec2 mouse model of Sjögren's Syndrome (SS), a human autoimmune disease characterized primarily by severe dry mouth and dry eye symptoms. Results indicate that annexin genes Anax1-7 and -11 exhibited upregulated expressions and the initial timing for these upregulations occurred as early as 8 weeks of age and prior to any covert signs of a SS-like disease. While the profiles of the two glands were similar, they were not identical, suggesting the possibility that the SS-like disease may not be uniform in the two glands. Nevertheless, this early pre-clinical and concomitant upregulated expression of this specific set of alarmins within the immune-targeted organs represents a potential target for identifying the pre-clinical stage in human SS as well, a fact that would clearly impact future interventions and therapeutic strategies.

Targeting DAMPs with nucleic acid scavengers to treat lupus

Systemic lupus erythematosus (SLE) is a chronic and often progressive autoimmune disorder marked clinically by a variable constellation of symptoms including fatigue, rash, joint pains, and kidney damage. The lungs, heart, gastrointestinal system, and brain can also be impacted, and individuals with lupus are at higher risk for atherosclerosis, thrombosis, thyroid disease, and other disorders associated with chronic inflammation . Autoimmune diseases are marked by erroneous immune responses in which the target of the immune response is a "self"-antigen, or autoantigen, driven by the development of antigen-specific B or T cells that have overcome the normal systems of self-tolerance built into the development of B and T cells. SLE is specifically characterized by the production of autoantibodies against nucleic acids and their binding proteins, including anti-double stranded DNA, anti-Smith (an RNA binding protein), and many others . These antibodies bind their nuclear-derived antigens to form immune complexes that cause injury and scarring through direct deposition in tissues and activation of innate immune cells . In over 50% of SLE patients, immune complex aggregation in the kidneys drives intrarenal inflammation and injury and leads to lupus nephritis, a progressive destruction of the glomeruli that is one of the most common causes of lupus-related death . To counter this pathology increasing attention has turned to developing approaches to reduce the development and continued generation of such autoantibodies. In particular, the molecular and cellular events that lead to long term, continuous activation of such autoimmune responses have become the focus of new therapeutic strategies to limit renal and other pathologies in lupus patients. The focus of this review is to consider how the innate immune system is involved in the development and progression of lupus nephritis and how a novel approach to inhibit innate immune activation by neutralizing the activators of this response, called Damage Associated Molecular Patterns, may represent a promising approach to treat this and other autoimmune disorders.

CT-M8 Mice: A New Mouse Model Demonstrates That Basophils Have a Nonredundant Role in Lupus-Like Disease Development

Tissue-specific mouse models are essential tools to decipher the role of each cell compartment and/or their expressed genes in the pathophysiology of diseases. Here, we describe a new knock-in mouse model allowing expression of both the fluorescent protein tdTomato and the CRE recombinase selectively in the basophil compartment under the control of the Mcpt8 gene. These “CT-M8” mice did not show any abnormalities in their peripheral distribution of major immune cell populations nor their basophil function. CT-M8 mice allowed the identification of basophils by immunofluorescence and flow cytometry and basophil-specific Cre-mediated floxed gene deletion. Breeding of our CT-M8 mice with the ROSA26^{flox-stop-DTA} mice led to the generation of basophil-deficient mice with no detectable abnormalities in other cell compartments. These mice were then used to document basophil involvement in systemic lupus erythematosus (SLE) pathophysiology since we previously reported by transient depletion of these cells during the course of an ongoing disease that they support and amplify autoantibody production in two distinct lupus-like mouse models (Lyn^−/− and pristane-induced). Here, constitutive basophil deficiency prevented pristane-induced lupus-like disease development by limiting autoantibody titers and renal damages. Therefore, basophils have a nonredundant role in pristane-induced lupus-like disease and are involved in both its induction and amplification. This CT-M8 new mouse model will allow us to finely decipher the role of basophils and their expressed genes in health and disease.

Should Renal Inflammation Be Targeted While Treating Hypertension?

Despite extensive research and a plethora of therapeutic options, hypertension continues to be a global burden. Understanding of the pathological roles of known and underexplored cellular and molecular pathways in the development and maintenance of hypertension is critical to advance the field. Immune system overactivation and inflammation in the kidneys are proposed alternative mechanisms of hypertension, and resistant hypertension. Consideration of the pathophysiology of hypertension in chronic inflammatory conditions such as autoimmune diseases, in which patients present with autoimmune-mediated kidney inflammation as well as hypertension, may reveal possible contributors and novel therapeutic targets. In this review, we 1) summarize current therapies used to control blood pressure and their known effects on inflammation; 2) provide evidence on the need to target renal inflammation, specifically, and especially when first-line and combinatory treatment efforts fail; and 3) discuss the efficacy of therapies used to treat autoimmune diseases with a hypertension/renal component. We aim to elucidate the potential of targeting renal inflammation in certain subsets of patients resistant to current therapies.

AMG853, A Bispecific Prostaglandin D2 Receptor 1 and 2 Antagonist, Dampens Basophil Activation and Related Lupus-Like Nephritis Activity in Lyn-Deficient Mice

Systemic lupus erythematosus is a complex autoimmune disease during which patients develop autoantibodies raised against nuclear antigens. During the course of the disease, by accumulating in secondary lymphoid organs (SLOs), basophils support autoreactive plasma cells to amplify autoantibody production. We have recently shown that murine lupus-like disease could be controlled by 10 days of oral treatment with a combination of prostaglandin D₂ (PGD₂) receptor (PTGDR) antagonists through the inhibition of basophil activation and recruitment to SLOs. Importantly, inhibiting solely PTGDR-1 or PTGDR-2 was ineffective, and the development of lupus-like disease could only be dampened by using antagonists for both PTGDR-1 and PTGDR-2. Here, we aimed at establishing a proof of concept that a clinically relevant bispecific antagonist of PTGDR-1 and PTGDR-2 could be efficient to treat murine lupus-like nephritis. Diseased Lyn-deficient female mice received treatment with AMG853 (vidupiprant, a bispecific PTGDR-1/PTGDR-2 antagonist) for 10 days. This led to the dampening of basophil activation and recruitment in SLOs and was associated with a decrease in plasmablast expansion and immunoglobulin E (IgE) production. Ten days of treatment with AMG853 was consequently sufficient in reducing the dsDNA-specific IgG titers, circulating immune complex glomerular deposition, and renal inflammation, which are hallmarks of lupus-like disease. Thus, bispecific PTGDR-1 and PTGDR-2 antagonists, such as AMG853, are a promising class of drugs for the treatment or prevention of organ damage in systemic lupus erythematosus.

Autoantibodies against specific post-translationally modified proteins are present in patients with lupus and associate with major neuropsychiatric manifestations

Background

Although autoantibodies are an important hallmark of systemic lupus erythematosus (SLE), most are not specific for SLE or any of its clinical manifestations. Autoantibodies against post-translationally modified (PTM) proteins have been studied extensively in rheumatoid arthritis and associate with disease progression. While PTMs have also been detected in patients with SLE, studies on anti-PTM antibodies remain scarce. We studied the presence of anti-PTM antibodies in SLE and neuropsychiatric SLE (NPSLE), a manifestation that lacks serological markers.

Methods

IgG antibody responses against six PTMs (malondialdehyde–acetaldehyde adducts (MAA), advanced glycation end-products (AGE), carbamylation (CarP), citrullination, acetylation and nitration) were tested using ELISA in sera of 349 patients with SLE (mean age 44±13 years; 87% female) and compared with 108 healthy controls. Levels and positivity were correlated with clinical features and SLE manifestations.

Results

Anti-MAA, anti-AGE and anti-CarP antibodies were more prevalent in SLE compared with controls (MAA: 29% vs 3%, AGE: 18% vs 4%, CarP: 14% vs 5%, all p≤0.0001). Anti-MAA and anti-AGE antibodies correlated with clinical manifestations and serological inflammatory markers. Patients with major NPSLE showed higher positivity of anti-MAA (39% vs 24%, p=0.01) and anti-CarP antibodies (20% vs 11%, p=0.04) than patients without major NPSLE. In addition, anti-PTM antibody levels correlated with brain volumes, an objective measure of nervous system involvement.

Conclusions

In our NPSLE cohort, a subset of patients with SLE have anti-PTM antibodies against MAA, AGE and CarP modified proteins. Interestingly, anti-MAA and anti-CarP were more prevalent in NPSLE, a manifestation for which no biomarkers exist.

Phase 3, long-term, open-label extension period of safety and efficacy of belimumab in patients with systemic lupus erythematosus in China, for up to 6 years

Objectives

To evaluate the long-term safety and efficacy of belimumab in patients with systemic lupus erythematosus (SLE) in China.

Methods

In this phase 3, open-label extension period, eligible completers of study BEL113750 (NCT01345253) received intravenous belimumab 10 mg/kg monthly for ≤6 years. The primary endpoint was safety. Secondary endpoints included the SLE Responder Index (SRI)-4 response rate, severe SLE flares and changes in prednisone use. Analyses were based on observed data from the first dose of belimumab through to study end.

Results

Of the 424 patients who received belimumab, 215 (50.7%) completed the study, 208 (49.1%) withdrew and 1 patient died. Overall, 359/424 (84.7%) patients had adverse events (AEs), and 96/424 (22.6%) had serious AEs. 26/424 (6.1%) patients discontinued study treatment/withdrew from the study due to AEs. Postinfusion systemic reaction rate was 1.5 events/100 patient-years. Herpes zoster infection rate was 3.0 events/100 patient-years, of which 0.4 events/100 patient-years were serious events. One papillary thyroid cancer and one vaginal cancer were reported in year 0–1 and year 3–4, respectively. There were no completed suicides/suicide attempts and no reports of serious depression. The proportion of SRI-4 responders increased progressively (year 1, week 24: 190/346 (54.9%); year 5, week 48: 66/82 (80.5%)). Severe flares were experienced by 55/396 (13.9%) patients. For 335 patients with baseline prednisone-equivalent dose >7.5 mg/day, the number of patients with a dose reduction to ≤7.5 mg/day increased over time (year 1, week 24: 30/333 (9.0%); year 5, week 48: 36/67 (53.7%)).

Conclusions

Favourable safety profile and disease control appeared to be maintained in patients with SLE in China for ≤6 years, consistent with previous belimumab studies.

Diagnosing and Managing Clinically Silent Lupus Nephritis and Anti-neutrophil Cytoplasmic Antibody-Associated Vasculitis Overlap Syndrome: A Clinical Challange

Lupus nephritis is typically associated with anti-nuclear antibodies and anti-double-stranded DNA antibodies resulting in the intrarenal immune complex deposition. Levels of anti-double-stranded DNA antibodies reflect disease activity in these patients. With negative anti-double-stranded DNA antibodies, establishing a diagnosis of lupus nephritis is difficult. Lupus nephritis overlapped with anti-neutrophil cytoplasmic antibody-associated vasculitis is both a diagnostic and therapeutic dilemma. Herein, we describe a case of an asymptomatic 41-year-old female who had incidental findings of low hemoglobin and elevated serum creatinine. Making a clinical diagnosis of lupus nephritis and anti-neutrophil cytoplasmic antibody-associated vasculitis in an asymptomatic patient can be challenging and must be made based on the interpretation of evolving serology, imaging studies, and histopathology. Based on extensive workup, the patient was diagnosed with concurrent lupus nephritis and anti-neutrophil cytoplasmic antibody-associated vasculitis overlap syndrome warranting immediate immunosuppressive therapy.

Vascular Inflammation in Mouse Models of Systemic Lupus Erythematosus

Vascular inflammation mediated by overly activated immune cells is a significant cause of morbidity and mortality in systemic lupus erythematosus (SLE). Several mouse models to study the pathogenesis of SLE are currently in use, many of which have different mechanisms of pathogenesis. The diversity of these models allows interrogation of different aspects of the disease pathogenesis. To better determine the mechanisms by which vascular inflammation occurs in SLE, and to assist future researchers in choosing the most appropriate mouse models to study cardiovascular complications in SLE, we suggest that direct comparisons of vascular inflammation should be conducted among different murine SLE models. We also propose the use of in vitro vascular assays to further investigate vascular inflammation processes prevalent among different murine SLE models.

Synthesis and biological and physico-chemical characterization of glycodendrimers and oligopeptides for the treatment of systemic lupus erythematosus

Anti-(ds)-DNA antibodies are the serological hallmark of Systemic Lupus Erythematosus (SLE). They assemble in the bloodstream with (ds)-DNA, forming immunocomplexes, which spread all over the body causing, among the other symptoms, lupic glomerulonephritis. Pathological manifestations of the disease may be reduced by destabilizing or inhibiting the formation of the immunocomplexes. In this respect, glycodendrimers showed peculiar interacting abilities towards this kind of biomolecule. Various generations of open-shell maltose-decorated poly(amidoamine) (PAMAM) and poly(propyleneimine) (PPI) dendrimers and two oligopeptides with different polyethylene glycol units were synthesized and characterized, and then tested for their anti-SLE activity. The activity of glycodendrimers and oligopeptides was evaluated in human plasma from patients with SLE, compared to healthy plasma, by means of an enzyme-linked immunosorbent assay (ELISA), and electron paramagnetic resonance (EPR) characterization using spin-label and spin-probe techniques. Different strategies for the immunocomplex formation were tested. The results show that both kinds of glycodendrimers and oligopeptides inhibited the formation of immunocomplexes. Also, a partial breakdown of preformed immunocomplexes was observed. Both ELISA and EPR analyses indicated a better activity of glycodendrimers compared to oligopeptides, the 3^rd generation PPI dendrimer being the most promising against SLE. This study highlights the possibility to develop a new class of dendritic therapeutics for the treatment of Lupus in pre-clinical studies.

Identification of mitofusin 1 and complement component 1q subcomponent-binding protein as mitochondrial targets in systemic lupus erythematosus

OBJECTIVE

Mitochondria are organelles that possess several bacterial features such as a double-stranded genome with hypomethylated CpG islets, formylated proteins, and cardiolipin-containing membranes. In systemic lupus erythematosus (SLE), mitochondria and their inner components are released into the extracellular space, potentially eliciting a pro-inflammatory response by the immune system. While cardiolipin and mitochondrial DNA and RNA are confirmed targets of autoantibodies, other antigenic mitochondrial proteins in SLE remain to be identified. Herein, we aim to characterize the protein repertoire recognized by anti-mitochondrial antibodies (AMA) in SLE patients.

METHODS

Using shotgun proteomic profiling, we identified 1345 proteins, 431 of which were associated with the mitochondrial proteome. Immunoreactivities to several of these candidates were assessed by direct ELISA in serum samples from a local cohort (healthy: n=30, SLE: n=87) and associated with demographic and disease characteristics.

RESULTS

We determined that IgGs to the C1q-binding protein (C1qBP) are significantly elevated in SLE patients included in our cohort (p=0.049) and are associated with positivity for lupus anticoagulant (p=0.049). IgG against the mitochondrial protein mitofusin 1 (Mfn1) displayed promising performances in the prediction of SLE diagnoses (aOR: 2.99, 95%CI: 1.39-6.43, p=0.0044) in our cohort. Moreover, anti-Mfn1 were associated with positivity to anti-phospholipids (p=0.011) and anti-dsDNA (p=0.0005).

CONCLUSION

This study presents the mitochondrial repertoire targeted in SLE, indicating that autoantibodies can recognize secreted and/or surface proteins of mitochondrial origin. Profiling of the AMA repertoire in large prospective cohorts may improve our knowledge on mitochondrial biomarkers and their usefulness for patient stratification.

Role of inhibitory B cell co-receptors in B cell self-tolerance to non-protein antigens

Antibodies to non-protein antigens such as nucleic acids, polysaccharides, and glycolipids play important roles in both host defense against microbes and development of autoimmune diseases. Although non-protein antigens are not recognized by T cells, antibody production to non-protein antigens involve T cell-independent mechanisms such as signaling through TLR7 and TLR9 in antibody production to nucleic acids. Although self-reactive B cells are tolerized by various mechanisms including deletion, anergy, and receptor editing, T cell tolerance is also crucial in self-tolerance of B cells to protein self-antigen because self-reactive T cells induce autoantibody production to these self-antigens. However, presence of T cell-independent mechanism suggests that T cell tolerance is not able to maintain B cell tolerance to non-protein self-antigens. Lines of evidence suggest that B cell response to non-protein self-antigens such as nucleic acids and gangliosides, sialic acid-containing glycolipids, are suppressed by inhibitory B cell co-receptors CD72 and Siglec-G, respectively. These inhibitory co-receptors recognize non-protein self-antigens and suppress BCR signaling induced by these antigens, thereby inhibiting B cell response to these self-antigens. Inhibitory B cell co-receptors appear to be involved in B cell self-tolerance to non-protein self-antigens that can activate B cells by T cell-independent mechanisms.

Association between HLA alleles and sub-phenotype of childhood steroid-sensitive nephrotic syndrome

BACKGROUND

Few studies have addressed the effects of human leukocyte antigen (HLA) alleles on different clinical sub-phenotypes in childhood steroid-sensitive nephrotic syndrome (SSNS), including SSNS without recurrence (SSNSWR) and steroid-dependent nephrotic syndrome/frequently relapse nephrotic syndrome (SDNS/FRNS). In this study, we investigated the relationship between HLA system and children with SSNSWR and SDNS/FRNS and clarified the value of HLA allele detection for precise typing of childhood SSNS.

METHODS

A total of 241 Chinese Han individuals with SSNS were genotyped using GenCap-WES Capture Kit, and four-digit resolution HLA alleles were imputed from available Genome Wide Association data. The distribution and carrying frequency of HLA alleles in SSNSWR and SDNS/FRNS were investigated. Additionally, logistic regression and mediating effects were used to examine the relationship between risk factors for disease process and HLA system.

RESULTS

Compared with SSNSWR, significantly decreased serum levels of complement 3 (C3) and complement 4 (C4) at onset were detected in SDNS/FRNS (C3, P < 0.001; C4, P = 0.018). The average time to remission after sufficient initial steroid treatment in SDNS/FRNS was significantly longer than that in SSNSWR (P = 0.0001). Low level of C4 was further identified as an independent risk factor for SDNS/FRNS (P = 0.008, odds ratio = 0.174, 95% confidence interval 0.048-0.630). The HLA-A*11:01 allele was independently associated with SSNSWR and SDNS/FRNS (P = 0.0012 and P = 0.0006, respectively). No significant HLA alleles were detected between SSNSWR and SDNS/FRNS. In addition, a mediating effect among HLA-I alleles (HLA-B*15:11, HLA-B*44:03 and HLA-C*07:06), C4 level and SDNS/FRNS was identified.

CONCLUSIONS

HLA-I alleles provide novel genetic markers for SSNSWR and SDNS/FRNS. HLA-I antigens may be involved in steroid dependent or frequent relapse in children with SSNS as mediators of immunoregulation.

Immunogenetic Relationship of HLA-G 14 bp Insertion/Deletion Polymorphism and Toll-Like Receptor 9 with Systemic Lupus Erythematosus in Egyptian Patients: A Case-Control Study

Introduction

The level of expression of the immunoregulatory human leukocyte antigen-G (HLA-G) has been suggested to play a role in the immunopathogenesis of systemic lupus erythematosus (SLE). A 14 bp insertion/deletion (ins/del) polymorphism in the 3ˊuntranslated region of HLA-G gene may influence the level of expression. The role of Toll-like receptor 9 (TLR9) in the pathogenesis of SLE has been highlighted. Data among Egyptian patients are quite limited.

Purpose

To detect the association of HLA-G 14 bp ins/del gene polymorphism with the susceptibility to SLE and to correlate TLR9 serum level with disease activity among Egyptian patients.

Patients and Methods

A case-control study that included 102 SLE female patients and 102 healthy matched volunteers as controls was carried out. Disease activity in patients was determined using the modified Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). HLA-G 14 bp ins/del genotype was detected by polymerase chain reaction (PCR). TLR9 serum level was estimated using enzyme-linked immunosorbent assay (ELISA) technique.

Results

The ins/ins genotype was significantly increased among SLE patients compared to healthy subjects (58.8% vs 9.8%; odds ratio [OR] = 11.79, P < 0.001). The 14 bp ins allele was significantly more frequent in SLE patients than in healthy subjects (65.7% vs 27.9%, respectively) and significantly associated with an increased risk of SLE (OR 4.94, P < 0.001). The mean TLR9 serum level showed a significant increase in SLE patients compared to healthy subjects (397.04±137.86 vs 195.22±45.14 ng/L, p < 0.001) and was significantly associated with disease activity as well as to patients’ HLA-G genotypes (p < 0.001).

Conclusion

Among Egyptian population, HLA-G 14 bp ins/ins homozygous genotype and ins allele may constitute a potential risk for SLE susceptibility, while TLR9 serum level is significantly associated with disease activity.

Lupus band test can be used in combination with anti-chromatin antibodies and complement analysis to predict transition from cutaneous to systemic lupus

The lupus band test (LBT) is frequently performed for patients with lupus erythematosus (LE) but its capacity to discriminate cutaneous (C)LE from systemic (S)LE is debated, as well as its association with serum antinuclear antibodies (ANA) and complement reduction. Among 158 patients, 56 received retrospectively a diagnosis of CLE, 37 have SLE and 65 other skin disorders. Considering 29 clinical, histopathologic, LBT, and serological parameters: 5 parameters were effective in distinguishing LE from other skin disorders (e.g. skin photosensitivity, LBT positivity, basal vacuolar changes, thickening of the basement membrane, and anti-SSA-60 kDa); and 8 parameters were able to separate SLE from CLE (e.g. arthritis, lupus nephritis, hematological manifestations, Raynaud/sicca manifestations, anti-chromatin, anti-dsDNA, and low levels of C3/4). A positive LBT was further determined to be associated with systemic manifestations when associated with anti-chromatin response and complement reduction in the profile of patients evolving to a systemic form of lupus.

CAR Treg: A new approach in the treatment of autoimmune diseases

Regulatory T cells (Tregs) have the role of regulating self-tolerance, and suppressing immune responses. Defects in Treg function and number can lead to in loss of tolerance or autoimmune disease. To treat or control autoimmune diseases, one of the options is to develop immune tolerance for Tregs cell therapy, which includes promotion and activation. Recently, cell-based treatment as a promising approach to increase cells function and number has been developed. Cell therapy by chimeric T antigen receptor (CAR-T) cells has shown significant efficacy in the treatment of leukemia, which has led researchers to use CAR-T cells in other diseases like autoimmune diseases. Here, we describe the existing treatments for autoimmune diseases and the available treatments based on Treg, their benefits and restrictions for implementation in clinical trials. We also discussed potential solutions to overcome these limitations. It seems novel designs of CARs to be new hope for autoimmune diseases and expected to be a potential cure option in a wide array of disease in the future. Therefore, it is very important to address this issue and increase information about it.

Antibodies to neurofilament light as potential biomarkers in multiple sclerosis

Background and objective

The concentration of neurofilament light (NfL) protein in cerebrospinal fluid (CSF) and blood is widely considered as a quantitative measure of neuro-axonal injury. Immune reactivity to NfL released into extracellular fluids induces specific autoantibody response. We investigated the levels and avidity of antibodies to NfL in patients with multiple sclerosis (MS) treated with disease-modifying therapies (DMTs) and their correlation with disease worsening and NfL protein concentration.

Methods

We conducted a prospective longitudinal study in 246 patients with MS (125 DMT-treated and 121 untreated at baseline). Serum levels of NfL antibodies, antibody avidity and immune complexes were determined by ELISA. NfL protein was measured using the Simoa platform. Clinical variables were tested for their association with the measured parameters in multivariate generalised estimating equation models.

Results

Multivariate analysis showed that levels of NfL antibodies were higher in progressive MS compared with clinically isolated syndrome (CIS)/relapsing remitting multiple sclerosis (RRMS) (p=0.010). Anti-NfL levels drop with increasing disability score (Expanded Disability Status Scale (EDSS)) (p=0.002), although conversely, were significantly elevated in CIS/RRMS after a recent EDSS increase (p=0.012). Patients receiving DMTs showed decreased levels of anti-NfL (p=0.008), high-avidity antibodies (p=0.017) and immune-complexes compared with untreated CIS/RRMS. Patients with MS switching to natalizumab showed lower levels of anti-NfL but higher immune complexes compared with healthy controls (p=0.0071). A weak association was observed between the levels of NfL protein and NfL antibodies.

Conclusions

These results support the potential usefulness of quantifying antibody response to NfL as potential markers of progression and treatment response in MS and need to be considered when interpreting peripheral blood NfL levels.

Metabolic Analysis of Potential Key Genes Associated with Systemic Lupus Erythematosus Using Liquid Chromatography-Mass Spectrometry

The biological mechanism underlying the pathogenesis of systemic lupus erythematosus (SLE) remains unclear. In this study, we found 21 proteins upregulated and 38 proteins downregulated by SLE relative to normal protein metabolism in our samples using liquid chromatography-mass spectrometry. By PPI network analysis, we identified 9 key proteins of SLE, including AHSG, VWF, IGF1, ORM2, ORM1, SERPINA1, IGF2, IGFBP3, and LEP. In addition, we identified 4569 differentially expressed metabolites in SLE sera, including 1145 reduced metabolites and 3424 induced metabolites. Bioinformatics analysis showed that protein alterations in SLE were associated with modulation of multiple immune pathways, TP53 signaling, and AMPK signaling. In addition, we found altered metabolites associated with valine, leucine, and isoleucine biosynthesis; one carbon pool by folate; tyrosine metabolism; arginine and proline metabolism; glycine, serine, and threonine metabolism; limonene and pinene degradation; tryptophan metabolism; caffeine metabolism; vitamin B6 metabolism. We also constructed differently expressed protein-metabolite network to reveal the interaction among differently expressed proteins and metabolites in SLE. A total of 481 proteins and 327 metabolites were included in this network. Although the role of altered metabolites and proteins in the diagnosis and therapy of SLE needs to be further investigated, the present study may provide new insights into the role of metabolites in SLE.

Coexistence of Rheumatoid Arthritis, Systemic Lupus Erythematosus, Sjogren Syndrome, Antiphospholipid Syndrome, and Ankylosing Spondylitis

A 37-year-old Bangladeshi woman presented with low back and several joints pain and swelling for months together; there was significant morning stiffness for more than two hours. Repeated abortions, dry eye, hair fall, photosensitivity, and oral ulcer were the additional complaints. Clinical examination unveiled asymmetrical peripheral and both sacroiliac joint tenderness, positive modified Schober's test, and limited chest expansion. Schirmer's test was positive. The history of rheumatoid arthritis (RA) and ankylosing spondylitis (AS) among 1st-degree relatives was also significant. Biochemical analysis revealed pancytopenia, raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), and mild microscopic proteinuria. The patient was seropositive for rheumatoid factor (RF), antibodies against cyclic citrullinated peptides (anti-CCP), antinuclear antibody (ANA), anti-Sm antibody, anti-Sjögren's-syndrome-related antigen A and B (anti-SSA/SSB), antiphospholipid (aPL-IgG/IgM), and HLA B27; however, serum complement (C3 and C4) levels were normal. Basal cortisol level measured elevated. Besides, X-ray and MRI of lumbosacral spines demonstrated sacroiliitis. There was radiological cardiomegaly, echocardiography unveiled atrial regurgitation, and ascending aorta aneurysm. Based on the abovementioned information, RA, AS, and systemic lupus erythematosus (SLE) have been diagnosed. Moreover, the patient developed Sjogren's syndrome (SS), antiphospholipid lipid syndrome (APS), Cushing syndrome, ascending aorta aneurysm, and atrial regurgitation. Her disease activity score for RA (DAS28), DAS for AS (ASDAS), SLE disease activity index (SLEDAI), and Systemic Lupus International Collaborating Clinics/American College of Rheumatology (SLICC/ACR) scores were 3.46, 2.36, 23, and 5, respectively. The patient received hydroxychloroquine (200 mg daily), pulsed cyclophosphamide, prednisolone (20 mg in the morning), and naproxen 500 mg (twice daily). To our best knowledge, this is the first report documenting RA, AS, and SLE with secondary SS and APS.

Potential for Antigen-Specific Tolerizing Immunotherapy in Systematic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic complex systemic autoimmune disease characterized by multiple autoantibodies and clinical manifestations, with the potential to affect nearly every organ. SLE treatments, including corticosteroids and immunosuppressive drugs, have greatly increased survival rates, but there is no curative therapy and SLE management is limited by drug complications and toxicities. There is an obvious clinical need for safe, effective SLE treatments. A promising treatment avenue is to restore immunological tolerance to reduce inflammatory clinical manifestations of SLE. Indeed, recent clinical trials of low-dose IL-2 supplementation in SLE patients showed that in vivo expansion of regulatory T cells (Treg cells) is associated with dramatic but transient improvement in SLE disease markers and clinical manifestations. However, the Treg cells that expanded were short-lived and unstable. Alternatively, antigen-specific tolerance (ASIT) approaches that establish long-lived immunological tolerance could be deployed in the context of SLE. In this review, we discuss the potential benefits and challenges of nanoparticle ASIT approaches to induce prolonged immunological tolerance in SLE.

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.

Immune-Related Urine Biomarkers for the Diagnosis of Lupus Nephritis

The kidney is one of the main organs affected by the autoimmune disease systemic lupus erythematosus. Lupus nephritis (LN) concerns 30-60% of adult SLE patients and it is significantly associated with an increase in the morbidity and mortality. The definitive diagnosis of LN can only be achieved by histological analysis of renal biopsies, but the invasiveness of this technique is an obstacle for early diagnosis of renal involvement and a proper follow-up of LN patients under treatment. The use of urine for the discovery of non-invasive biomarkers for renal disease in SLE patients is an attractive alternative to repeated renal biopsies, as several studies have described surrogate urinary cells or analytes reflecting the inflammatory state of the kidney, and/or the severity of the disease. Herein, we review the main findings in the field of urine immune-related biomarkers for LN patients, and discuss their prognostic and diagnostic value. This manuscript is focused on the complement system, antibodies and autoantibodies, chemokines, cytokines, and leukocytes, as they are the main effectors of LN pathogenesis.

Clinical and serological associations of autoantibodies in patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disorder characterized by the formation of antigen-antibody complexes which trigger an immune response. We investigate certain autoantibodies including nucleosome, double-stranded DNA (dsDNA), Smith, ribonucleoprotein, and Sjögren's syndrome-related antigens, and examine their associations with disease activity, damage accrual, and SLE-related clinical and serological manifestations in patients with SLE. We conducted a cross-sectional study with a total 293 patients (90.4% female, mean age 46.87±12.94 years) and used the Systemic Lupus Erythematosus Disease Activity Index 2000 and Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) to evaluate disease activity and disease-related damage, respectively. Systemic Lupus Erythematosus Disease Activity Index scores were significantly higher in anti-nucleosome-positive (3.87±2.72 vs 2.52±2.76, p=0.004) and anti-dsDNA-positive (3.08±2.91 vs 2.04±2.48, p=0.010) patients compared with patients without these antibodies. SDI scores were also significantly higher in anti-nucleosome-positive patients (1.61±1.99 vs 0.89±1.06, p=0.004). The presence of antinucleosome (p=0.019) and anti-dsDNA antibodies (p=0.001) both correlated significantly with the incidence of nephritis; anti-La antibodies were associated with arthritis (p=0.022), and we also observed a relationship between the presence of antinucleosome antibodies and leukopenia (p=0.011). Patients with antinucleosome or anti-dsDNA antibodies had a higher disease activity and were likely to have nephritis. Antinucleosome was also associated with more damage accrual. A greater understanding of these autoantibodies could lead to the development of new approaches to more accurate assessments of SLE.

Association of lipoproteins and thyroid hormones with cognitive dysfunction in patients with systemic lupus erythematosus

Background

Neuropsychiatric manifestations occur in up to 75% of adult systemic lupus erythematosus (SLE) patients and are one of the major causes of death in SLE patients. Cognitive dysfunction is a typical clinical feature of neuropsychiatric SLE (NPSLE), which seriously affects the quality of life of patients. Dyslipidaemia and thyroid symptoms, which are prevalent in SLE patients, have both been related to neuropsychiatric disturbances, including significant psychiatric and cognitive disturbances. This study aimed to investigate whether cognitive dysfunction in patients with SLE was related to the expression of serum thyroid hormone and lipoprotein levels.

Methods

A total of 121 patients with SLE and 65 healthy controls (HCs) at Nanjing Drum Tower Hospital completed a cognitive function test, and 81 SLE patients were divided into a high-cognition (n = 33) group and a low-cognition group (n = 48). The clinical and laboratory characteristics of the patients were compared; moreover, correlations between serum HDL-C, LDL-C, F-T3 and F-T4 levels and cognitive function were analysed. Serum levels of APOE, APOA1, IGF-1, and IGFBP7 in 81 patients were detected by ELISA, and the correlation between these four proteins and cognition was analysed separately.

Results

The patients with SLE with abnormal cognitive function were less educated than the HCs. For low-cognition patients, the levels of albumin, F-T3 (P <  0.05) and F-T4 decreased, while D-dimer, anti-dsDNA antibody, and IgM levels increased. Serum F-T3 and F-T4 levels positively correlated with cognition. Furthermore, serum protein levels of APOE and APOA1 showed no difference between the high- and low-cognition groups. However, the serum APOE levels were negatively correlated with line orientation scores, and APOA1 levels were positively correlated with coding scores.

Conclusions

Serum F-T3 and F-T4 levels were both positively correlated with four indexes of cognition (language was the exception), while serum APOE levels were negatively correlated with line orientation scores, APOA1 levels were positively correlated with coding scores, and IGFBP7 levels were negatively correlated with figure copy scores. These results demonstrated that F-T3 and F-T4 might be clinical biomarkers of cognitive dysfunction in SLE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41927-021-00190-7.

Phase 2, Randomized, Placebo-Controlled Trial of Dapirolizumab Pegol in Patients with Moderate-to-Severe Active Systemic Lupus Erythematosus

Objective

To evaluate the dose–response, efficacy and safety of dapirolizumab pegol (DZP) in patients with SLE.

Methods

Adults with moderately to severely active SLE (SLEDAI-2K score ≥6 and ≥1 BILAG A or ≥2 BILAG B domain scores), receiving stable CS (≤40 mg/day prednisone-equivalent), antimalarial or immunosuppressant drugs were included. Patients with stable LN (proteinuria ≤2 g/day) not receiving high-dose CS or CYC were permitted entry. Randomized patients received placebo or i.v. DZP (6/24/45 mg/kg) and standard-of-care (SOC) treatment every 4 weeks to week 24, after which patients received only SOC to week 48. The primary objective was to establish a dose–response relationship based on week 24 BILAG-Based Composite Lupus Assessment (BICLA) responder rates.

Results

All DZP groups exhibited improvements in clinical and immunological outcomes vs placebo at week 24; however, BICLA responder rates did not fit pre-specified dose–response models [best-fitting model (E_max): P = 0.07]. Incidences of serious treatment-emergent adverse events across DZP groups were low and similar to placebo. Following DZP withdrawal, SLEDAI-2K, physician’s global assessment (PGA), BILAG, and Cutaneous Lupus Erythematosus Disease Area and Severity Index (CLASI) scores stabilized; BICLA and SLE Responder Index (SRI-4) responder rates declined (likely due to interventions with disallowed escape medications), BILAG flares increased, and immunologic parameters returned towards baseline.

Conclusions

Although the primary objective was not met, DZP appeared to be well tolerated, and patients exhibited improvements across multiple clinical and immunological measures of disease activity after 24 weeks relative to placebo. The potential clinical benefit of DZP warrants further investigation.

False Positive Results in SARS-CoV-2 Serological Tests for Samples From Patients With Chronic Inflammatory Diseases

Patients with chronic inflammatory diseases are often treated with immunosuppressants and therefore are of particular concern during the SARS-CoV-2 pandemic. Serological tests will improve our understanding of the infection and immunity in this population, unless they tests give false positive results. The aim of this study was to evaluate the specificity of SARS-Cov-2 serological assays using samples from patients with chronic inflammatory diseases collected prior to April 2019, thus defined as negative. Samples from patients with multiple sclerosis (MS, n=10), rheumatoid arthritis (RA, n=47) with or without rheumatoid factor (RF) and/or anti-cyclic citrullinated peptide antibodies (anti-CCP2) and systemic lupus erythematosus (SLE, n=10) with or without RF, were analyzed for SARS-CoV-2 antibodies using 17 commercially available lateral flow assays (LFA), two ELISA kits and one in-house developed IgG multiplex bead-based assay. Six LFA and the in-house validated IgG assay correctly produced negative results for all samples. However, the majority of assays (n=13), gave false positive signal for samples from patients with RA and SLE. This was most notable in samples from RF positive RA patients. No false positive samples were detected in any assay using samples from patients with MS. Poor specificity of commercial serological assays could possibly be, at least partly, due to interfering antibodies in samples from patients with chronic inflammatory diseases. For these patients, the risk of false positivity should be considered when interpreting results of the SARS-CoV-2 serological assays.

Protein-Based Immunome Wide Association Studies (PIWAS) for the Discovery of Significant Disease-Associated Antigens

Identification of the antigens associated with antibodies is vital to understanding immune responses in the context of infection, autoimmunity, and cancer. Discovering antigens at a proteome scale could enable broader identification of antigens that are responsible for generating an immune response or driving a disease state. Although targeted tests for known antigens can be straightforward, discovering antigens at a proteome scale using protein and peptide arrays is time consuming and expensive. We leverage Serum Epitope Repertoire Analysis (SERA), an assay based on a random bacterial display peptide library coupled with next generation sequencing (NGS), to power the development of Protein-based Immunome Wide Association Study (PIWAS). PIWAS uses proteome-based signals to discover candidate antibody-antigen epitopes that are significantly elevated in a subset of cases compared to controls. After demonstrating statistical power relative to the magnitude and prevalence of effect in synthetic data, we apply PIWAS to systemic lupus erythematosus (SLE, n=31) and observe known autoantigens, Smith and Ribosomal protein P, within the 22 highest scoring candidate protein antigens across the entire human proteome. We validate the magnitude and location of the SLE specific signal against the Smith family of proteins using a cohort of patients who are positive by predicate anti-Sm tests. To test the generalizability of the method in an additional autoimmune disease, we identified and validated autoantigenic signals to SSB, CENPA, and keratin proteins in a cohort of individuals with Sjogren’s syndrome (n=91). Collectively, these results suggest that PIWAS provides a powerful new tool to discover disease-associated serological antigens within any known proteome.

ARID5B rs10821936 and rs10994982 gene polymorphism and susceptibility to juvenile systemic lupus erythematosus and lupus nephritis

BACKGROUND

The prevalence of SLE and the spectrum of clinical manifestations vary widely in different races and geographical populations.

OBJECTIVE

To investigate the possible role of ARID5B rs10821936 and rs10994982 polymorphism as a risk factor for the development of SLE in children (jSLE) and to evaluate their role in relation to clinical manifestations especially lupus nephritis (LN).

METHODS

DNA extraction and Real-time PCR genotyping of ARID5B rs10821936 and rs10994982 were done for 104 jSLE and 282 healthy controls.

RESULTS

The C allele and C containing genotypes (CC, CT and CC+CT) of ARID5B rs10821936 were higher in children with SLE (p = 0.009, OR = 1.56, 0.037, OR = 2.35, 0.016, OR = 1.81 and 0.008 OR = 1.88 respectively). ARID5B rs10994982 alleles, genotypes and haplotypes are not associated with jSLE (p > 0.05). The ARID5B rs10821936 and rs10994982 genotypes showed non-significant associations with LN, proliferative versus non proliferative and biopsy grades (p > 0.05).

CONCLUSION

ARID5B rs10821936 SNP may be a susceptibility risk factor for juvenile SLE in the studied cohort of Egyptian children.

Association of signal transducer and activator of transcription 4 gene (restriction site7582694) single nucleotide polymorphism with systemic lupus erythematosus

Background — Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease characterized by production of autoantibodies and deposition within various organs. The incidence of SLE averages 5 cases per 100,000 population. Various genome wide studies have shown association of STAT4 (signal transducer and activator of transcription 4) gene with SLE and lupus nephritis (LN). Therefore, this study was designed to determine single nucleotide polymorphism (SNP) in STAT4 (rs7582694) in local SLE, LN patients and healthy controls. Objective — To determine the frequency of STAT4 (rs7582694) gene polymorphism in systemic lupus erythematosus, lupus nephritis patients and healthy controls. Methods — It was a case-control study. Eighty samples were recruited for each of two study groups. Deoxyribonucleic acid (DNA) extraction was carried out using standard phenol chloroform method. Further, samples were processed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) conventional technique and genotypes were determined. Polymorphism analysis and allele frequencies were compared between groups using the chi-square test. Project was approved by the Ethical Review Board at the University of Health Sciences, Lahore, Pakistan. Results — Females were more inclined towards developing SLE. The study unveiled that SNP in STAT 4 gene (rs7582694) was associated with SLE patients in Pakistani population which indicates that this may play a role in susceptibility to SLE. Moreover, we infer that genetic variations within STAT4 (rs7582694) predispose patients to lupus nephritis. It was also evident that GG and GC genotypes were more susceptible of further transforming into SLE and LN. Conclusion: The findings of this study may contribute to a better understanding of underlying etiological and prognostic factors regarding SLE and LN.

Potential role of viral infection and B cells as a linker between innate and adaptive immune response in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease that involves several organ systems. Although B cells play a key role in SLE pathogenesis, the mechanisms behind B cell dysregulation in SLE development remained controversial. Finding the modules containing highly co-expressed genes in B cells could explain biological pathways involved in the pathogenesis of SLE, which may further support the reasons for the altered function of B cells in SLE disease. A total of three microarray gene expression datasets were downloaded from Gene Expression Omnibus. SLE samples were prepared from the purified B lymphocyte cells of the patients who have not received immunosuppressive drugs as well as high dose immunocytotoxic therapies or steroids. A weighted gene co-expression network was then constructed to find the relevant modules implicated in the SLE progression. Among 17 identified modules, 3 modules were selected through mapping to STRING and finding the ones that had highly connection at the protein level. These modules clearly indicate the involvement of several pathways in the pathogenesis of SLE including viral infection, adaptive immune response, and innate immune response in B lymphocytes. The WGCN analysis further revealed the co-expressed genes involved in both innate and adaptive immune systems. Mix infections and primary immunodeficiency might also dysregulate B lymphocytes, which may facilitate SLE development. As such, identifying novel biomarkers and pathways in lupus would be of importance.

Antinuclear Autoantibodies in Health: Autoimmunity Is Not a Synonym of Autoimmune Disease

The incidence of autoimmune diseases is increasing. Antinuclear antibody (ANA) testing is a critical tool for their diagnosis. However, ANA prevalence in healthy persons has increased over the last decades, especially among young people. ANA in health occurs in low concentrations, with a prevalence up to 50% in some populations, which demands a cutoff revision. This review deals with the origin and probable physiological or compensatory function of ANA in health, according to the concept of immunological clearance, theory of autoimmune regulation of cell functions, and the concept of functional autoantibodies. Considering ANA titers ≤1:320 as a serological marker of autoimmune diseases seems inappropriate. The role of anti-DFS70/LEDGFp75 autoantibodies is highlighted as a possible anti-risk biomarker for autoimmune rheumatic disorders. ANA prevalence in health is different in various regions due to several underlying causes discussed in the review, all influencing additive combinations according to the concept of the mosaic of autoimmunity. Not only are titers, but also HEp-2 IFA) staining patterns, such as AC-2, important. Accepting autoantibodies as a kind of bioregulator, not only the upper, but also the lower borders of their normal range should be determined; not only their excess, but also a lack of them or "autoimmunodeficiency" could be the reason for disorders.

Therapeutic Targeting of Autoreactive B Cells: Why, How, and When?

B lymphocytes play critical roles in the development of autoimmunity, acting as autoantibody manufacturers, antigen-presenting cells, and producers of cytokines. Pan-B cell depletion has demonstrated efficacy in treatment of many autoimmune disorders, but carries with it an unfavorable safety profile due to global immune suppression. Hence, attention has turned to the potential of autoantigen-specific B cell targeted therapies, which would deplete or silence pathogenic self-antigen-reactive cells while sparing B cells needed for immune defense. Here, we discuss the antigen-specific B cell-targeted approaches that are under development or are under consideration, that could be employed to allow for more precise therapy in the treatment of autoimmunity. Lastly, we discuss some of the challenges associated with antigen-specific B cell targeting that may impact their clinical applicability.

Oxidative Stress and Lipid Mediators Modulate Immune Cell Functions in Autoimmune Diseases

Autoimmune diseases, including psoriasis, systemic lupus erythematosus (SLE), and rheumatic arthritis (RA), are caused by a combination of environmental and genetic factors that lead to overactivation of immune cells and chronic inflammation. Since oxidative stress is a common feature of these diseases, which activates leukocytes to intensify inflammation, antioxidants could reduce the severity of these diseases. In addition to activating leukocytes, oxidative stress increases the production of lipid mediators, notably of endocannabinoids and eicosanoids, which are products of enzymatic lipid metabolism that act through specific receptors. Because the anti-inflammatory CB2 receptors are the predominant cannabinoid receptors in leukocytes, endocannabinoids are believed to act as anti-inflammatory factors that regulate compensatory mechanisms in autoimmune diseases. While administration of eicosanoids in vitro leads to the differentiation of lymphocytes into T helper 2 (Th2) cells, eicosanoids are also necessary for the different0iation of Th1 and Th17 cells. Therefore, their antagonists and/or the genetic deletion of their receptors abolish inflammation in animal models of psoriasis—RA and SLE. On the other hand, products of non-enzymatic lipid peroxidation, especially acrolein and 4-hydroxynonenal-protein adducts, mostly generated by an oxidative burst of granulocytes, may enhance inflammation and even acting as autoantigens and extracellular signaling molecules in the vicious circle of autoimmune diseases.

Recognize Yourself-Innate Sensing of Non-LTR Retrotransposons

Although mobile genetic elements, or transposons, have played an important role in genome evolution, excess activity of mobile elements can have detrimental consequences. Already, the enhanced expression of transposons-derived nucleic acids can trigger autoimmune reactions that may result in severe autoinflammatory disorders. Thus, cells contain several layers of protective measures to restrict transposons and to sense the enhanced activity of these “intragenomic pathogens”. This review focuses on our current understanding of immunogenic patterns derived from the most active elements in humans, the retrotransposons long interspersed element (LINE)-1 and Alu. We describe the role of known pattern recognition receptors in nucleic acid sensing of LINE-1 and Alu and the possible consequences for autoimmune diseases.

Glycosylation in Autoimmune Diseases

Autoimmune diseases are accompanied by changes in protein glycosylation, in both the immune system and target tissues. The best-studied alteration in autoimmunity is agalactosylation of immunoglobulin G (IgG), characterized primarily in rheumatoid arthritis (RA), and then detected also in systemic lupus erythematosus (SLE), inflammatory bowel disease (IBD), and multiple sclerosis (MS). The rebuilding of IgG N-glycans in RA correlates with the relapses and remissions of the disease, is associated with physiological states such as pregnancy but also depends on applied anti-inflammatory therapy. In turn, a decreased core fucosylation of the whole pool of IgG N-glycans is a serum glycomarker in autoimmune thyroid diseases (AITD) encompassing Hashimoto's thyroiditis (HT) and Grave's disease (GD). However, fucosylation of anti-thyroglobulin IgG (an immunological marker of HT) was elevated in HT serum. Core fucosylation of IgG oligosaccharides was also lowered in MS and SLE. In AITD and IBD, chronic inflammation T lymphocytes showed the reduced expression of MGAT5 gene encoding β1,6-N-acetylglucosaminyltransferase V (GnT-V) responsible for β1,6-branching of N-glycans, which is important for T cell receptor activation. Structural changes of glycans have a profound effect on the pro-inflammatory activity of immune cells and serum immune proteins, including IgG in autoimmunity.