Systemic Lupus Erythematosus Phenotype Research Articles

LASSO-derived nomogram for early identification of pediatric monogenic lupus.

Monogenic lupus is defined as systemic lupus erythematosus (SLE)/SLE-like patients with either dominantly or recessively inherited pathogenic variants in a single gene with high penetrance. However, because the clinical phenotype of monogenic SLE is extensive and overlaps with that of classical SLE, it causes a delay in diagnosis and treatment. Currently, there is a lack of early identification models for clinical practitioners to provide early clues for recognition. Our goal was to create a clinical model for the early identification of pediatric monogenic lupus, thereby facilitating early and precise diagnosis and treatment for patients. This retrospective cohort study consisted of 41 cases of monogenic lupus treated at the Department of Pediatrics at Peking Union Medical College Hospital from June 2012 to December 2022. The control group consisted of classical SLE patients recruited at a 1:2 ratio. Patients were randomly divided into a training group and a validation group at a 7:3 ratio. A logistic regression model was established based on the least absolute shrinkage and selection operator to generate the coefficient plot. The predictive ability of the model was evaluated using receiver operator characteristic curves and the area under the curve (AUC) index. A total of 41 cases of monogenic lupus patients and 82 cases of classical SLE patients were included. Among the monogenic lupus cases (with a male-to-female ratio of 1:1.05 and ages of onset ranging from birth to 15years), a total of 18 gene mutations were identified. The variables included in the coefficient plot were age of onset, recurrent infections, intracranial calcifications, growth and developmental delay, abnormal muscle tone, lymphadenopathy/hepatosplenomegaly, and chilblain-like skin rash. Our model demonstrated satisfactory diagnostic performance through internal validation, with an AUC value of 0.97 (95% confidence interval = 0.92-0.97). We summarized and analyzed the clinical characteristics of pediatric monogenic lupus and developed a predictive model for early identification by clinicians. Clinicians should exercise high vigilance for monogenic lupus when the score exceeds - 9.032299.

Screening of Environmental Chemicals to Characterize Exposures in Participants With Systemic Lupus Erythematosus.

There is a need to characterize exposures associated with the pathogenesis of systemic lupus erythematosus (SLE). In this pilot study, we explore a hypothesis-free approach that can measure thousands of exogenous chemicals in blood ("exposome") in patients with SLE and unaffected controls. This cross-sectional study analyzed a cohort of patients with prevalent SLE (n=285) and controls (n=106). Plasma was analyzed by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF/MS). Mass spectrometry features present in at least 25% of all samples were selected for association analysis (n=2,737). Features were matched to potential chemicals using available databases. Association analysis of abundances of features with SLE status was performed, adjusting for age and sex. We also explored features associated with SLE phenotypes, sociodemographic factors, and current medication use. We found 30 features significantly associated with SLE status (Bonferroni P < 0.05). Of these, seven matched chemical names based on databases. These seven features included phthalate metabolites, a formetanate metabolite, and eugenol. The abundance of acid pesticides differed between patients with SLE and controls (Bonferroni P < 0.05). Two unmatched features were associated with a history of lupus nephritis, and one with anti-double-stranded DNA antibody production (Bonferroni P < 0.05). Seventeen features varied by self-reported race and ethnicity, including a polyfluoroalkyl substance (analysis of variance P < 1.69 × 10-5). Eleven features correlated with antimalarials, 6 with mycophenolate mofetil, and 29 with prednisone use. This proof-of-concept study demonstrates that LC-QTOF/MS is a powerful tool that agnostically detects circulating exogenous compounds. These analyses can generate hypotheses of disease-related exposures for future prospective, longitudinal studies.

The economic burden of systemic lupus erythematosus in Mexico

Aims Our cost of illness study aimed to provide an estimate of the burden related to systemic lupus erythematosus (SLE) in the Mexican context. Methods Our model was used to simulate the resource utilization and economic consequences over a period of 5 years for patients with SLE in Mexico. The model simulated four health states—three phenotypes of SLE, including mild, moderate, and severe states, and death. Clinical parameters were retrieved from the literature. Resource utilization in our model represents the most common practice in the Mexican healthcare system. These include disease management, transient events (e.g. infections, flares, and complications due to SLE-related organ damage), and indirect costs. Direct non-medical costs were not considered. One-way sensitivity analysis was performed. Results The number of targeted Mexican SLE patients was 57,754. The numbers of SLE patients diagnosed with mild, moderate, and severe phenotypes were 8,230, 44,291, and 5,233, respectively. Disease management costs, including the treatment of each phenotype and disease follow-up, were MXN 4 billion ($ 415 million); the costs of transient events (infections, flares, and consequences of SLE-related organ damage) were MXN 5 billion ($ 478 million). Productivity loss costs among adult employed Mexican patients with SLE were estimated at MXN 17 billion ($ 1.6 billion). The total SLE cost in Mexico over 5 years from the payer and societal perspectives is estimated at MXN 9 billion ($ 893 million) and 26 billion ($ 2.5 billion), respectively. Over 5 years, the costs per patient per year from the payer and societal perspectives were MXN 32,131($ 3,095) and MXN 91,661($ 8,830), respectively. Conclusion The findings pointed out the substantial economic burden associated with SLE, including the costs of disease progression and SLE transient events, such as flare-ups, infections, and organ damage, in addition to productivity loss due to work capacity impairment.

The economic burden of systemic lupus erythematosus in United Arab Emirates

Aims Our study aims to provide an enhanced comprehension of systemic lupus erythematosus (SLE) burden in United Arab Emirates (UAE), over a five-year period from payer and societal perspective. Materials and methods A Markov model was established to simulate the economic consequences of SLE among UAE population. It included four health states: i) the three phenotypes of SLE, representing mild, moderate, and severe states, and ii) death. Clinical parameters were retrieved from previous literature and validated using the Delphi panel—the most common clinical practice within the Emirati healthcare system. We calculated the disease management, transient events, and indirect costs by macro costing. One-way sensitivity analysis was conducted. Results The estimated number of SLE patients in our study was 13,359. The number of SLE patients with mild, moderate, and severe phenotypes was 3,914, 8,109, and 1,336, respectively. Disease management costs, including treatment of each phenotype and disease follow-up, were AED 2 billion ($0.89 billion), whereas the costs of transient events (infections, flares, and consequences of SLE-related organ damage) were AED 1 billion ($0.44 billion). The productivity loss costs among adult-employed patients with SLE in the UAE were estimated at AED 7 billion ($3.1 billion). The total SLE cost over five years from payer and societal perspectives is estimated at AED 3 ($1.3 billion) and 10 billion ($4.4 billion), respectively. Additionally, the costs per patient per year from the payer and societal perspectives were AED 45,960 ($20,610) and AED 148,468 ($66,578), respectively. Conclusion Our findings demonstrate that the burden of SLE in the UAE is enormous, mainly because of the costly complications and productivity loss. More awareness should be created to limit the progression of SLE and reduce the occurrence of flares, necessitating further economic evaluations of novel treatments that could help reduce the economic consequences of SLE in the UAE.

Clinical and economic burden of systemic lupus erythematosus in Colombia

Aims Our cost-of-illness (COI) model adopted payer and societal perspectives over five years to measure the economic burden of Systemic Lupus Erythematosus (SLE) in Colombia. Materials and methods A prevalence-based model was constructed to estimate costs and economic consequences for SLE patients in Colombia. The model included four health states: three phenotypes of SLE representing mild, moderate, and severe states and death. The clinical inputs were captured from the published literature and validated by the Delphi panel. Our model measured direct medical and indirect costs, including disease management, transient events, and indirect costs. One-way sensitivity analysis was also performed. Results The number of Colombian SLE patients was 37,498. The number of SLE patients with mild, moderate, and severe phenotypes was 5343, 28757 and 3,397, respectively. SLE-patients with moderate (Colombian pesos; COP 146 billion) and severe phenotypes (COP276 billion) incurred higher costs than those with mild phenotypes (COP2 billion), over 5 years. The total SLE cost in Colombia over five years from the payer and societal perspectives was estimated to be COP 915 billion and 8 trillion, respectively. The costs per patient per year from the payer and societal perspectives were COP 4,881,902 ($3,510) and COP 46,637,054 ($33,528), respectively. Conclusion The burden of SLE in Colombia over five years is substantially high, mainly due to the consequences of economic loss because it affects women and men of working age, in addition to the costs of SLE management and its consequences, such as flares, infection, and organ damage. Our COI indicated that disease management costs among patients with moderate and severe SLE were substantially higher than those among patients with a mild phenotype. Therefore, more attention should be paid to limiting the progression of SLE and the occurrence of flares, with the need for further economic evaluation of novel treatment strategies that help in disease control.

Longitudinal follow-up of mixed connective tissue disease and overlapping autoimmune diseases of childhood onset in the Afro-descendant population of the French West Indies

IntroductionOverlap autoimmune syndromes (OAS) and mixed connective tissue disease (MCTD) are rare in children. We performed a retrospective, longitudinal and descriptive study of Afro-Caribbean patients from the French West Indies followed for MCTD and OAS to describe their characteristics and outcomes during childhood.MethodsRetrospective study from January 2000 to 2023. Listings of patients were obtained from multiple sources: computerized hospital archives and national hospital-based surveillance system, registry of pediatricians and adult specialists in internal medicine and the national registry for rare diseases. MCTD was defined according to Kasukawa’s criteria. OAS was defined as overlapping features of systemic lupus erythematosus (SLE), systemic sclerosis (SSc), and dermatomyositis/autoimmune myositis (DM/AM).ResultsSixteen patients were included over a 23-year period (10 MCTD and 6 OAS). The incidence was 0.23 per 100,000 children-years. The mean age at diagnosis was 11.9 years old (2.4–17) with median follow up of 7.9 years (2.1–19.6). SLE phenotype was present in the highest, followed by SSc and DM/AM. Patients had an average of three flares during childhood (1–7). A quarter (25%) had symptomatic pulmonary arterial hypertension (PAH). Ninety-four percent received steroids during follow-up and 88% required a corticosteroid-sparing therapy. Three patients (19%) developed SLE after more than 10y of follow-up. There were no death and no chronic organ failure.ConclusionThis is the largest pediatric cohort of MCTD and OAS in Afro-descendant patients treated in a country with a high standard of care. The clinical evolution did not differ between MCTD and OAS. The main complication was PAH, more frequent in our cohort.

COX5A as a potential biomarker for disease activity and organ damage in lupus.

Systemic Lupus Erythematosus (SLE) is a complex autoimmune disease with limited therapeutic targets or clinical outcome predictors. This study aimed to gain more insights into the underlying immunological pathways and prognostic biomarkers of SLE. Integrated analyses of RNA-seq data from 64 SLE and 62 healthy controls, examining 27 immune cell types to explore the key pathways and driver genes in SLE pathogenesis. Single-cell RNA sequencing data from the skin and kidney were used to determine the association of COX5A expression with organ damage. The associations of COX5A with SLE phenotypes were further evaluated in two independent cohorts, and receiver operating characteristic (ROC) curves were constructed to assess the value of COX5A as a biomarker for disease activity and organ damage in SLE. We found that oxidative phosphorylation (OXPHOS) is the most significantly altered metabolic pathway in SLE, especially in effector T cells. Notably, we identified an OXPHOS-related enzyme, COX5A, whose expression was significantly higher in effector T cells than in naïve T cells and showed associations with disease activity, organ damage, and steroid treatment of SLE. Furthermore, ROC curves showed that COX5A is a robust biomarker for disease activity, kidney involvement, and new-onset skin lesions, with the area under the curve (AUC) values of 0.880, 0.801, and 0.805, respectively. Our results identified the OXPHOS signature as a prominent feature in SLE T cells, and COX5A as a potential candidate biomarker for disease activity and organ damage in SLE.

An interpretable machine learning pipeline based on transcriptomics predicts phenotypes of lupus patients

Machine learning (ML) has the potential to identify subsets of patients with distinct phenotypes from gene expression data. However, phenotype prediction using ML has often relied on identifying important genes without a systems biology context. To address this, we created an interpretable ML approach based on blood transcriptomics to predict phenotype in systemic lupus erythematosus (SLE), a heterogeneous autoimmune disease. We employed a sequential grouped feature importance algorithm to assess the performance of gene sets, including immune and metabolic pathways and cell types, known to be abnormal in SLE in predicting disease activity and organ involvement. Gene sets related to interferon, tumor necrosis factor, the mitoribosome, and Tcell activation were the best predictors of phenotype with excellent performance. These results suggest potential relationships between the molecular pathways identified in each model and manifestations of SLE. This ML approach to phenotype prediction can be applied to other diseases and tissues.

Clinical and immunologic features of the phenotype of systemic lupus erythematosus combined with Sjögren's syndrome

The problem of clinical and immunological heterogeneity of systemic lupus erythematosus (SLE) is of great interest, especially the combination of SLE and Sjögren's syndrome (SjS) determines a more favorable prognosis and specifics of therapy.Objective: to characterize the clinical and immunological features of SLE combined with SjS.Material and methods. The retrospective study included 44 patients with SLE combined with SjS and 356 patients with SLE without SjS, hospitalized at the V.A. Nasonova Research Institute of Rheumatology between 2013 and 2021. The two groups of patients were compared in terms of life expectancy, clinical manifestations, laboratory parameters and therapy.Results and discussion. The following phenotypic features of the clinical and immunological variant of SLE combined with SjS were found: significantly longer duration of SLE (p&lt;0.01); higher incidence of polyarthritis (p=0.01) and Raynaud's syndrome (p&lt;0.003) at disease onset. Subacute cutaneous lupus erythematosus, Raynaud's syndrome, peripheral nervous system involvement (sensory polyneuropathy and distal sensory-motor polyneuropathy) were found more frequently in SLE combined with SjS than in SLE without SjS, p&lt;0.0001. Among laboratory abnormalities in SLE patients with SjS, leukopenia (p&lt;0.0001), antibodies to SSA/Ro, SSB/La, and rheumatoid factor (p&lt;0.0001) were observed in a greater number of cases. In the group of SLE combined with SjS, the chronic variant of SLE course according to the classification of V.A. Nasonova, and lower activity were observed, which didn't not require therapy with high doses of glucocorticoids; in this group, rituximab (p&lt;0.01), cyclophosphamide and methotrexate were used significantly more often.Conclusion. Thus, significant clinical and laboratory differences were found between SLE with SjS and without SjS. They determine prognosis, approaches to pathogenetic therapy and monitoring.

Molecular Mechanisms of Lupus Susceptibility Allele PBX1D.

Pre-B cell leukemia homeobox 1 (PBX1) controls chromatin accessibility to a large number of genes in various cell types. Its dominant negative splice isoform, PBX1D, which lacks the DNA and Hox-binding domains, is expressed more frequently in the CD4+ T cells from lupus-prone mice and patients with systemic lupus erythematosus than healthy control subjects. PBX1D overexpression in CD4+ T cells impaired regulatory T cell homeostasis and expanded inflammatory CD4+ T cells. In this study, we showed that PBX1 message expression is downregulated by activation in CD4+ T cells as well as in B cells. PBX1D protein was less stable than the normal isoform, PBX1B, and it is degraded through the ubiquitin-proteasome-dependent pathway. The DNA binding domain lacking in PBX1D has two putative ubiquitin binding sites, K292 and K293, that are predicted to be in direct contact with DNA. Mutation of K292-293 reduced PBX1B stability to a level similar to PBX1D and abrogated DNA binding. In addition, contrary to PBX1B, PBX1D is retained in the cytoplasm without the help of the cofactors MEIS or PREP1, indicating a different requirement for nuclear translocation. Overall, these findings suggest that multiple post-transcriptional mechanisms are responsible for PBX1D loss of function and induction of CD4+ T cell inflammatory phenotypes in systemic lupus erythematosus.

Clinical features and genetic biomarkers associated with different phenotypes of systemic lupus erythematosus in Paraguayan patients.

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by a heterogeneous clinical picture that makes the diagnosis and follow-up of these patients difficult. This study aimed to identify correlations between clinical, immunological, and genetic biomarkers and clinical manifestations in SLE. A retrospective study of data from medical records and immunological and genetic studies of SLE patients in Paraguay was carried out. A descriptive analysis was performed based on the type of variable. Human leukocyte antigen (HLA) allele frequencies (DPA1, DPB1, DQA1, DQB1, and DRB1) were calculated, and univariate logistic regression analyses were performed between each of the explanatory variables and the presence or absence of each phenotype. Odds ratios, 95% confidence intervals, and p values were recorded. Associations with p<0.05 were considered statistically significant. 104 SLE patients were included: 86% were female, with a mean age of 32.80±10.36 years. An association was identified between anti-double stranded DNA (anti-dsDNA) and the presence of the renal phenotype and between anti-dsDNA and the absence of the joint and hematological phenotypes. Immunoglobulin M isotype rheumatoid factor was associated with the absence of a renal phenotype. HLA-DQB1*02:02 and HLA-DRB1*07:01 were associated with the cutaneous phenotype. An association was identified between age at disease onset over 30 years and the presence of the joint phenotype. No other associations were identified. Potential clinical, immunological, and genetic biomarkers of phenotypes have been identified in SLE Paraguayan patients.

Disturbance of neuron–microglia crosstalk mediated by GRP78 in Neuropsychiatric systemic lupus erythematosus mice

ObjectivesNeuropsychiatric systemic lupus erythematosus (NPSLE) is a serious phenotype of systemic lupus erythematosus (SLE). The disturbance of neuron–microglia crosstalk is recently revealed in many neuropsychiatric diseases but was not well studied in NPSLE. We found glucose regulatory protein 78 (GRP78), a marker of endoplasmic reticulum stress, was significantly increased in the cerebrospinal fluid (CSF) of our NPSLE cohort. We, therefore, investigated whether GRP78 can act as a mediator between the neuron–microglia crosstalk and is involved in the pathogenic process of NPSLE.MethodsSerum and CSF parameters were analyzed in 22 NPSLE patients and controls. Anti-DWEYS IgG was injected intravenously into mice to establish a model of NPSLE. Behavioral assessment, histopathological staining, RNA-seq analyses, and biochemical assays were performed to examine the neuro-immunological alterations in the mice. Rapamycin was intraperitoneally administered to define the therapeutic effect.ResultsThe level of GRP78 was elevated significantly in the CSF of the patients with NPSLE. An increase in GRP78 expression, accompanied by neuroinflammation and cognitive impairment, was also found in the brain tissues of the NPSLE model mice induced by anti-DWEYS IgG deposition on hippocampal neurons. In vitro experiments demonstrated that anti-DWEYS IgG could stimulate neurons to release GRP78, which activated microglia via TLR4/MyD88/NFκB pathway to produce more pro-inflammatory cytokines and promote migration and phagocytosis. Rapamycin ameliorated GRP78-inducing neuroinflammation and cognitive impairment in anti-DWEYS IgG-transferred mice.ConclusionGRP78 acts as a pathogenic factor in neuropsychiatric disorders via interfering neuron–microglia crosstalk. Rapamycin may be a promising therapeutic candidate for NPSLE.

202-OR: Automated Cluster Analysis by Machine Learning Reveals Important Dissimilarities in the Immune Phenotype of T1D, MS, and SLE

Background: Dysfunction of the immune cell control and break-down of self-tolerance are important in chronic conditions such as type 1 diabetes (T1D), multiple sclerosis (MS), rheumatoid arthritis (RA) or systemic lupus erythematosus (SLE). Investigating common patterns and dissimilarities between these diseases can help identifying new therapeutic intervention strategies for T1D. Methods: Unsupervised, automated gating and machine learning (ML) was used to identify clusters of immune cell phenotypes in fluorochrome stained PBMCs from patients with T1D (n=70), RA (n=70), SLE (n=50), MS (n=60) and healthy controls (n=70). The pipeline includes unsupervised pre-gating, FlowSOM clustering, and a statistical analysis (MANOVA) to check for significant differential abundances of cell populations among the conditions. Results: The unsupervised analysis revealed important differences in the immune cell phenotype of peripheral CD4posT cells between the different auto-immune conditions. IL7alpha receptor (CD127) positive T cell clusters, such as CD3hiCD4hiCD15sposCD127hiCD161med cells are significantly decreased in T1D (p&amp;lt;0.001) compared to MS. Clusters of IL7Rpos memory T cells, expressing the co-stimulatory CD28 molecule are significantly increased in T1D (p&amp;lt;0.001) and SLE (p&amp;lt;0.001) compared to MS. Clusters including Treg-like phenotypes are significantly decreased in MS (p&amp;lt;0.001) compared to T1D, SLE and RA. Discussion: IL-7R (CD127) and its gene polymorphism plays a major role in MS and mediates homeostatic proliferation in T1D. In SLE serum sIL-7R is associated with disease activity. Using unsupervised machine learning we were able to identify interesting clusters of immune cells expressing CD127 that show significantly different abundancies. Learning from immune modifying therapies used in MS and SLE treatment could help to develop new strategies for future T1D (combinational)-therapies targeting IL7/IL7R complexes. Disclosure B.Prietl: None. J.Vera-ramos: None. V.Pfeifer: None. M.Khalil: Advisory Panel; Novartis, Biogen, Gilead Sciences, Inc., Merck &amp; Co., Inc., Research Support; Novartis, Biogen, Roche Pharmaceuticals. L.Herbsthofer: None. H.Sourij: Advisory Panel; Amgen Inc., Amryt Pharma Plc, Boehringer Ingelheim Inc., Eli Lilly and Company, Novo Nordisk A/S, Sanofi, Speaker's Bureau; Boehringer Ingelheim Inc., Novo Nordisk A/S, Bayer Inc., Sanofi. T.Pieber: Advisory Panel; Arecor, Novo Nordisk A/S, Consultant; Lilly, Research Support; AstraZeneca, Novo Nordisk A/S, Sanofi, Speaker's Bureau; Roche Diagnostics. Funding JDRF/Lupus Research Alliance/National MS Society Joint RFA (2-SRA-2021-1043-S-B)

The Inflammatory Profile Orchestrated by Inducible Nitric Oxide Synthase in Systemic Lupus Erythematosus.

(1) Background: The pathogenesis of systemic lupus erythematosus (SLE) involves complicated and multifactorial interactions. Inducible nitric oxide synthase overactivation (iNOS or NOS2) could be involved in SLE pathogenesis and progression. This study explored the relationship between NOS2-associated inflammation profiles and SLE phenotypes. (2) Methods: We developed a prospective, case control study that included a group of 86 SLE subjects, a group of 73 subjects with lupus nephritis, and a control group of 60 people. Laboratory determinations included serum C reactive protein (CRP-mg/L), enzymatic activity of NOS2 (U/L), serum levels of inducible factors of hypoxia 1 and 2 (HIF1a-ng/mL, HIF2a-ng/mL), vascular endothelial growth factor VEGF (pg/mL), matrix metalloproteinases 2 and 9 (MMP-2, MMP-9-ng/mL), thrombospondin 1 (TSP-1-ng/mL), and soluble receptor of VEGF (sVEGFR-ng/mL). (3) Results: CRP, NOS2, HIF-1a, HIF-2a, VEGF, MMP-2, and MMP-9 were significantly increased, while TSP-1 and sVEGFR were decreased in the SLE and lupus nephritis groups compared with the control group. The variations in these biomarkers were strongly associated with the decrease in eGFR and increase in albuminuria. (4) Conclusions: The inflammatory phenotype of SLE patients, with or without LN, is defined by NOS2 and hypoxia over-expression, angiogenesis stimulation, and inactivation of factors that induce resolution of inflammation in relation with eGFR decline.

Limited Association between Antibodies to Oxidized Low-Density Lipoprotein and Vascular Affection in Patients with Established Systemic Lupus Erythematosus.

Patients with systemic lupus erythematosus (SLE) are at an increased risk of cardiovascular disease. We aimed to evaluate whether antibodies to oxidized low-density lipoprotein (anti-oxLDL) were associated with subclinical atherosclerosis in patients with different SLE phenotypes (lupus nephritis, antiphospholipid syndrome, and skin and joint involvement). Anti-oxLDL was measured by enzyme-linked immunosorbent assay in 60 patients with SLE, 60 healthy controls (HCs) and 30 subjects with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). Intima-media thickness (IMT) assessment of vessel walls and plaque occurrence were recorded using high-frequency ultrasound. In the SLE cohort, anti-oxLDL was again assessed in 57 of the 60 individuals approximately 3 years later. The levels of anti-oxLDL in the SLE group (median 5829 U/mL) were not significantly different from those in the HCs group (median 4568 U/mL), while patients with AAV showed significantly higher levels (median 7817 U/mL). The levels did not differ between the SLE subgroups. A significant correlation was found with IMT in the common femoral artery in the SLE cohort, but no association with plaque occurrence was observed. The levels of anti-oxLDL antibodies in the SLE group were significantly higher at inclusion compared to 3 years later (median 5707 versus 1503 U/mL, p < 0.0001). Overall, we found no convincing support for strong associations between vascular affection and anti-oxLDL antibodies in SLE.

Modulation of murine lupus by Aconitate Decarboxylase 1

Abstract Mitochondrial synthesis of itaconate by myeloid cells (monocytes and macrophages) is mediated by the TCA cycle enzyme Aconitate Decarboxylase 1 (Acod1). Upregulation of Acod1–itaconate pathway, occurs after activation of various Toll-like receptors (TLRs) or cytokine stimulation (TNF or type I Interferons). While various anti-inflammatory effects of the Acod1 – Itaconate pathway have been previously reported (e.g. decreases in IL-6 and IL-1β synthesis) the contribution of impairments in endogenous itaconate synthesis in systemic lupus erythematosus (SLE) remain poorly characterized. First, we explored and characterized Acod1 expression in bone marrow or monocyte-derived macrophages (BMDM and MDM, respectively) following in vitro imiquimod (IMQ) treatment. Then, we investigated the role of endogenous itaconate modulation in the development and severity of TLR-7 induced lupus using the IMQ model. 10-week-old wild type and Acod1 −/−mice were treated with topical IMQ cream for 5 weeks to induce an SLE phenotype. We found that Acod1 protein expression is induced in BMDM and MDM after 12 hours of IMQ stimulation, and this induction is partially dependent on IFNRa1 signaling. Moreover, Acod1 −/−BMDM treated with IMQ for 12 h displayed higher mRNA expression of il6, il1b, il18, ccl2, cxcl2, and cxcl9, together with an increase in pro-IL-1β protein levels. IL-6 and IL-1β production were also increased. After 5 weeks of in vivo IMQ topical treatment, Acod1 −/−mice have a higher concentration of circulating anti-dsDNA autoantibodies but a decrease in splenomegaly compared to the treated WT mice. These results, demonstrate a putative role for endogenous Acod1-itaconate pathway in the regulation of autoimmunity. This work is support by the NIH/NIAMS Intramural Research Program

Modeling of clinical phenotypes in systemic lupus erythematosus based on the platelet transcriptome and FCGR2a genotype

BackgroundThe clinical heterogeneity of SLE with its complex pathogenesis remains challenging as we strive to provide optimal management. The contribution of platelets to endovascular homeostasis, inflammation and immune regulation highlights their potential importance in SLE. Prior work from our group showed that the Fcγ receptor type IIa (FcγRIIa)–R/H131 biallelic polymorphism is associated with increased platelet activity and cardiovascular risk in SLE. The study was initiated to investigate the platelet transcriptome in patients with SLE and evaluate its association across FcγRIIa genotypes and distinct clinical features.MethodsFifty-one patients fulfilling established criteria for SLE (mean age = 41.1 ± 12.3, 100% female, 45% Hispanic, 24% black, 22% Asian, 51% white, mean SLEDAI = 4.4 ± 4.2 at baseline) were enrolled and compared with 18 demographically matched control samples. The FCGR2a receptor was genotyped for each sample, and RNA-seq was performed on isolated, leukocyte-depleted platelets. Transcriptomic data were used to create a modular landscape to explore the differences between SLE patients and controls and various clinical parameters in the context of FCGR2a genotypes.ResultsThere were 2290 differentially expressed genes enriched for pathways involved in interferon signaling, immune activation, and coagulation when comparing SLE samples vs controls. When analyzing patients with proteinuria, modules associated with oxidative phosphorylation and platelet activity were unexpectedly decreased. Furthermore, genes that were increased in SLE and in patients with proteinuria were enriched for immune effector processes, while genes increased in SLE but decreased in proteinuria were enriched for coagulation and cell adhesion. A low-binding FCG2Ra allele (R131) was associated with decreases in FCR activation, which further correlated with increases in platelet and immune activation pathways. Finally, we were able to create a transcriptomic signature of clinically active disease that performed significantly well in discerning SLE patients with active clinical disease form those with inactive clinical disease.ConclusionsIn aggregate, these data demonstrate the platelet transcriptome provides insight into lupus pathogenesis and disease activity, and shows potential use as means of assessing this complex disease using a liquid biopsy.

Platelet LGALS3BP as a Mediator of Myeloid Inflammation in Systemic Lupus Erythematosus.

Platelets are mediators of inflammation with immune effector cell properties and have been implicated in the pathogenesis of systemic lupus erythematosus (SLE). This study investigated the role of platelet-associated lectin, galactoside-binding, soluble 3 binding protein (LGALS3BP) as a mediator of inflammation in SLE and as a potential biomarker associated with clinical phenotypes. We performed RNA sequencing on platelets from patients with SLE (n=54) and on platelets from age-, sex-, and race/ethnicity-matched healthy controls (n=18) and measured LGALS3BP levels in platelet releasate and in circulating serum. We investigated the association between LGALS3BP levels and the prevalence, disease severity, and clinical phenotypes of SLE and studied platelet-mediated effects on myeloid inflammation. Platelets from patients with SLE exhibited increased expression of LGALS3BP (fold change 4.0, adjusted P=6.02 × 10-11 ). Platelet-released LGALS3BP levels were highly correlated with circulating LGALS3BP (R=0.69, P < 0.0001), and circulating LGALS3BP levels were correlated with the severity of disease according to the SLE Disease Activity Index (r=0.32, P=0.0006). Specifically, circulating LGALS3BP levels were higher in SLE patients with lupus nephritis than in patients with inactive disease (4.0 μg/ml versus 2.3 μg/ml; P < 0.001). Interferon-α induced LGALS3BP transcription and translation in a megakaryoblastic cell line (MEG-01) in a dose-dependent manner. Recombinant LGALS3BP and platelet releasates from SLE patients enhanced proinflammatory cytokine production by macrophages. Our results support that platelets act as potent effector cells that contribute to the pathogenesis of SLE by secreting proinflammatory LGALS3BP, which also represents a novel biomarker of SLE clinical activity.

Pediatric mixed connective tissue disease versus other overlap syndromes: a retrospective multicenter cohort study.

Pediatric mixed connective tissue disease (MCTD) is a subgroup of overlap syndromes. We aimed to compare the characteristics and outcomes in children with MCTD and other overlap syndromes. All MCTD patients met either Kasukawa or Alarcon-Segovia and Villareal criteria. The patients with other overlap syndromes had the features of ≥ 2 autoimmune rheumatic diseases but did not meet MCTD diagnostic criteria. Thirty MCTD (F/M = 28/2) and thirty (F/M = 29/1) overlap patients were included (disease onset < 18years). The most prominent phenotype at disease onset and the last visit was systemic lupus erythematosus (SLE) in the MCTD group; juvenile idiopathic arthritis and dermatomyositis/polymyositis, respectively, in the overlap group. At the last visit, systemic sclerosis (SSc) phenotype was more frequent among MCTD than overlap patients (60% vs. 33.3%; p = 0.038). The frequency of the predominant SLE phenotype had decreased (60% to 36.7%), while predominant SSc phenotype had increased (13.3% to 33.3%) during follow-up in MCTD patients. Weight loss (36.7% vs. 13.3%), digital ulcers (20% vs. 0), swollen hands (60% vs. 20%), Raynaud phenomenon (86.7% vs. 46.7%), hematologic involvement (70% vs. 26.7%), and anti-Sm positivity (29% vs. 3.3%) were more common, while Gottron papules (16.7% vs. 40%) were less frequent among MCTD than overlap patients (p < 0.05). A higher percentage of overlap patients achieved complete remission than MCTD patients (51.7% vs. 24.1%; p = 0.047). The disease phenotype and outcome differ between pediatric MCTD and other overlap syndromes where MCTD may be regarded as a more severe disease. Analyzing these patients could pave the way for early and effective treatment.

MODELING OF IMMUNOSENESCENCE WITH AGING IN SYSTEMIC LUPUS ERYTHEMATOSUS

Systemic lupus erythematosus (SLE) is an autoimmune disease affecting multiple systems and presenting with a wide range of clinical symptoms. Disease phenotype alters from childhood to old age. The possible reasons for these differences are genetic factors, changes in the hormonal status, and the aging immune system. As a result of the disease itself or as a side effect of medications, SLE patients often experience manifestations associated with aging like cardiovascular disease and infection susceptibility. Furthermore, immunosenescence, which commonly affects the elderly subjects, may result from the continued immune system activation during the natural history of SLE. In this study, we aimed to analyze the immunosenescence in SLE, the differences and similarities in SLE phenotype at different age groups, and possible reasons for these changes.