Disentangling the riddle of systemic lupus erythematosus with antiphospholipid syndrome: blood transcriptome analysis reveals a less-pronounced IFN-signature and distinct molecular profiles in venous versus arterial events.

INTRODUCTION: Systemic lupus erythematosus with antiphospholipid syndrome (SLE-APS) represents a challenging SLE endotype whose molecular basis remains unknown. METHODS: We analysed whole-blood RNA-sequencing data from 299 patients with SLE (108 SLE-antiphospholipid antibodies (aPL)-positive, including 67 SLE-APS; 191 SLE-aPL-negative) and 72 matched healthy controls (HC). Pathway enrichment analysis, unsupervised weighted gene coexpression network analysis and machine learning were applied to distinguish disease endotypes. RESULTS: Patients with SLE-APS demonstrated upregulated type I and II interferon (IFN) pathways compared with HC. Using a 100-gene random forests model, we achieved a cross-validated accuracy of 75.6% in distinguishing these two states. Additionally, the comparison between SLE-APS and SLE-aPL-negative revealed 227 differentially expressed genes, indicating downregulation of IFN-α and IFN-γ signatures, coupled with dysregulation of the complement cascade, B-cell activation and neutrophil degranulation. Unsupervised analysis of SLE transcriptome identified 21 gene modules, with SLE-APS strongly linked to upregulation of the 'neutrophilic/myeloid' module. Within SLE-APS, venous thromboses positively correlated with 'neutrophilic/myeloid' and 'B cell' modules, while arterial thromboses were associated with dysregulation of 'DNA damage response (DDR)' and 'metabolism' modules. Anticardiolipin and anti-ß2GPI positivity-irrespective of APS status-were associated with the 'neutrophilic/myeloid' and 'protein-binding' module, respectively. CONCLUSIONS: There is a hierarchical upregulation and-likely-dependence on IFN in SLE with the highest IFN signature observed in SLE-aPL-negative patients. Venous thrombotic events are associated with neutrophils and B cells while arterial events with DDR and impaired metabolism. This may account for their differential requirements for anticoagulation and provide rationale for the potential use of mTOR inhibitors such as sirolimus and the direct fIIa inhibitor dabigatran in SLE-APS.

Patients with neuropsychiatric involvement systemic lupus erythematosus experience poorer health-related quality of life and more fatigue than systemic lupus erythematosus patients with no neuropsychiatric involvement, irrespective of neuropsychiatric activity.

OBJECTIVES: Substantial proportions of patients with systemic lupus erythematosus (SLE) report poor health-related quality of life (HRQoL). Our objective was to investigate the impact of neuropsychiatric involvement (NP) in SLE on patient-reported outcomes. METHODS: We analysed data from four phase III trials (BLISS-52, BLISS-76, BLISS-SC, EMBRACE; N = 2968). The neuropsychiatric SLE (NPSLE) group comprised individuals with NP-British Isles Lupus Assessment group (BILAG) A/B/C/D or score in any descriptor of the NP-SLEDAI-2K at baseline (N = 350), while the non-NPSLE group consisted of patients with NP-BILAG E (N = 2618). HRQoL was assessed with the SF-36, EQ-5D-3L, and FACIT-F. Full health state (FHS) was defined as "no problems" in all EQ-5D dimensions. RESULTS: NPSLE patients reported lower scores in the SF-36 physical and mental component summary compared with the non-NPSLE population (mean±s.d.: 35.7±9.1 versus 39.6±9.6; p<0.001 and 37.3±12.1 versus 41.4±11.0; p<0.001, respectively). NPSLE patients also exhibited impaired HRQoL in all EQ-5D dimensions compared with non-NPSLE patients (p<0.05 for all). A substantially lower proportion among NPSLE patients experienced FHS in comparison with the non-NPSLE group (3.3% versus 14.5%; p<0.001). NPSLE was associated with severe fatigue (23.8±12.2 versus 31.5±11.6; p<0.001). Notably, our findings revealed no discernible distinctions between active and inactive NPSLE patients with regard to SF-36, EQ-5D, FHS, and FACIT-F scores. CONCLUSION: Neuropsychiatric involvement in patients with SLE has a detrimental effect on HRQoL experience and is associated with severe fatigue, regardless of the degree of neuropsychiatric disease activity. Early intervention is warranted in NPSLE patients to enhance long-term HRQoL experience.

Can we predict kidney involvement in patients with systemic lupus erythematosus? A retrospective cohort study with independent validation.

OBJECTIVES: To discern predictive factors for incident kidney involvement in patients with systemic lupus erythematosus (SLE). METHODS: Patients with SLE from the 'Attikon' Lupus cohort were monitored for lupus nephritis (LN), defined by kidney histology and/or classification criteria. Demographic and clinical characteristics at baseline were compared against patients who did not develop LN. LN-free survival curves were generated by Kaplan-Meier. A multivariate Cox proportional hazards model was used to identify independent predictors of LN. Independent validation was performed in the University of Crete Lupus registry. RESULTS: Among the 570 patients in the derivation cohort, 59 exhibited LN as their initial presentation, while an additional 66 developed LN during the follow-up period (collectively, 21.9% incidence). In the latter group, baseline factors predictive of subsequent kidney involvement were male sex (multivariable-adjusted [a]HR 4.31, 95% CI: 1.82-10.2), age of SLE diagnosis below 26 years (aHR 3.71, 95% CI: 1.84-7.48), high anti-dsDNA titre (aHR 2.48, 95% CI: 1.03-5.97) and low C3 and/or C4 (although not statistically significant, aHR 2.24, 95% CI: 0.83-6.05, p= 0.11). A combination of these factors at time of diagnosis conferred an almost 90-fold risk compared with serologically inactive, older, female patients (aHR 88.77, 95% CI : 18.75-420.41), signifying a very high-risk group. Independent validation in the Crete Lupus registry showed concordant results with the original cohort. CONCLUSION: Male sex, younger age and serologic activity at SLE diagnosis are strongly associated with subsequent kidney involvement. Vigilant surveillance and consideration of early use of disease-modifying drugs is warranted in these subsets of patients.

Impaired serotonin synthesis in hippocampus of murine lupus represents an early neuropsychiatric event.

BACKGROUND: Despite significant progress in understanding the mechanisms underlying hippocampal involvement in neuropsychiatric systemic lupus erythematosus (NPSLE), our understanding of how neuroinflammation affects the brain neurotransmitter systems is limited. To date, few studies have investigated the role of neurotransmitters in pathogenesis of NPSLE with contradictory results. METHODS: Hippocampal tissue from NZB/W-F1 lupus-prone mice and age-matched control strains were dissected in both pre-nephritic (3-month-old) and nephritic (6-month-old) stages. High-Performance Liquid Chromatography (HPLC) was used to evaluate the level of serotonin (5-HT), dopamine (DA), and their metabolites 5-HIAA and DOPAC, respectively, in mouse hippocampi. RESULTS: Lupus mice exhibit decreased levels of serotonin at the early stages of the disease, along with intact levels of its metabolite 5-HIAA. The 5-HT turnover ratio (5-HIAA/5-HT ratio) was increased in the hippocampus of lupus mice at pre-nephritic stage suggesting that low hippocampal serotonin levels in lupus are attributed to decreased serotonin synthesis. Both DA and DOPAC levels remained unaffected in lupus hippocampus at both early and late stages. CONCLUSION: Impaired hippocampal serotonin synthesis in the hippocampus of lupus-prone mice represents an early neuropsychiatric event. These findings may have important implications for the use of symptomatic therapy in diffuse NPSLE.

Restoration of aberrant gene expression of monocytes in systemic lupus erythematosus via a combined transcriptome-reversal and network-based drug repurposing strategy.

BACKGROUND: Monocytes -key regulators of the innate immune response- are actively involved in the pathogenesis of systemic lupus erythematosus (SLE). We sought to identify novel compounds that might serve as monocyte-directed targeted therapies in SLE. RESULTS: We performed mRNA sequencing in monocytes from 15 patients with active SLE and 10 healthy individuals. Disease activity was assessed with the Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K). Leveraging the drug repurposing platforms iLINCS, CLUE and L1000CDS2, we identified perturbagens capable of reversing the SLE monocyte signature. We identified transcription factors and microRNAs (miRNAs) that regulate the transcriptome of SLE monocytes, using the TRRUST and miRWalk databases, respectively. A gene regulatory network, integrating implicated transcription factors and miRNAs was constructed, and drugs targeting central components of the network were retrieved from the DGIDb database. Inhibitors of the NF-κB pathway, compounds targeting the heat shock protein 90 (HSP90), as well as a small molecule disrupting the Pim-1/NFATc1/NLRP3 signaling axis were predicted to efficiently counteract the aberrant monocyte gene signature in SLE. An additional analysis was conducted, to enhance the specificity of our drug repurposing approach on monocytes, using the iLINCS, CLUE and L1000CDS2 platforms on publicly available datasets from circulating B-lymphocytes, CD4+ and CD8+ T-cells, derived from SLE patients. Through this approach we identified, small molecule compounds, that could potentially affect more selectively the transcriptome of SLE monocytes, such as, certain NF-κB pathway inhibitors, Pim-1 and SYK kinase inhibitors. Furthermore, according to our network-based drug repurposing approach, an IL-12/23 inhibitor and an EGFR inhibitor may represent potential drug candidates in SLE. CONCLUSIONS: Application of two independent - a transcriptome-reversal and a network-based -drug repurposing strategies uncovered novel agents that might remedy transcriptional disturbances of monocytes in SLE.

Microglia activation in the presence of intact blood-brain barrier and disruption of hippocampal neurogenesis via IL-6 and IL-18 mediate early diffuse neuropsychiatric lupus.

INTRODUCTION: Inflammatory mediators are detected in the cerebrospinal fluid of systemic lupus erythematosus patients with central nervous system involvement (NPSLE), yet the underlying cellular and molecular mechanisms leading to neuropsychiatric disease remain elusive. METHODS: We performed a comprehensive phenotyping of NZB/W-F1 lupus-prone mice including tests for depression, anxiety and cognition. Immunofluorescence, flow cytometry, RNA-sequencing, qPCR, cytokine quantification and blood-brain barrier (BBB) permeability assays were applied in hippocampal tissue obtained in both prenephritic (3-month-old) and nephritic (6-month-old) lupus mice and matched control strains. Healthy adult hippocampal neural stem cells (hiNSCs) were exposed ex vivo to exogenous inflammatory cytokines to assess their effects on proliferation and apoptosis. RESULTS: At the prenephritic stage, BBB is intact yet mice exhibit hippocampus-related behavioural deficits recapitulating the human diffuse neuropsychiatric disease. This phenotype is accounted by disrupted hippocampal neurogenesis with hiNSCs exhibiting increased proliferation combined with decreased differentiation and increased apoptosis in combination with microglia activation and increased secretion of proinflammatory cytokines and chemokines. Among these cytokines, IL-6 and IL-18 directly induce apoptosis of adult hiNSCs ex vivo. During the nephritic stage, BBB becomes disrupted which facilitates immune components of peripheral blood, particularly B-cells, to penetrate into the hippocampus further augmenting inflammation with locally increased levels of IL-6, IL-12, IL-18 and IL-23. Of note, an interferon gene signature was observed only at nephritic-stage. CONCLUSION: An intact BBB with microglial activation disrupting the formation of new neurons within the hippocampus represent early events in NPSLE. Disturbances of the BBB and interferon signature are evident later in the course of the disease.

Relapses are common in severe hematologic systemic lupus erythematosus and may be prevented by early institution of immunosuppressive agents: Α real-life single-center study.

BACKGROUND: Hematologic manifestations are common in systemic lupus erythematosus (SLE), either at initial presentation or during the course of the disease, but data regarding their natural history are scarce. OBJECTIVE: To describe the characteristics, treatments, and outcomes of severe hematological manifestations in a large cohort of lupus patients. METHODS: Retrospective cohort study of patients in the "Attikon" lupus cohort who had a history of a severe hematologic manifestation, defined as autoimmune hemolytic anemia (AIHA) with hemoglobin < 8 g/dL, thrombocytopenia with platelet count < 30,000/mm3, Evans syndrome with hemoglobin < 8 g/dL, and/or platelet count < 30,000/mm3, neutropenia with < 500 neutrophils/mm3, thrombotic microangiopathy (TMA)/thrombotic thrombocytopenic purpura (TTP)-like syndrome, or macrophage activation syndrome (MAS). Demographic and clinical characteristics, treatments, and outcomes were recorded. RESULTS: From over 300 patients with hematologic manifestations, 41 qualified as severe (70.7% women, mean [SD] age at SLE diagnosis 42.6 [18.0] years). Hematologic manifestations preceded SLE diagnosis in 13 patients (31.7%), was concomitant to SLE diagnosis in 16 patients (39%), and occurred during the course of the disease in 12 (29.3%) patients, with a mean (SD) disease duration of 8.7 (5.5) years. Thrombocytopenia was the most common severe hematological manifestation (56.1%), followed by AIHA (17.1%) and TTP-like syndrome (12.2%). For initial treatment, all patients were treated with glucocorticoids (GC), while rituximab and cyclophosphamide were the most frequently used immunosuppressive agents. Following initial treatment, relapse occurred in 22 patients (53.7%). Compared to patients that did not relapse, those that relapsed had less often received concomitant immunosuppressive agents following treatment of initial episode (n = 17/23, 73.9% vs 5/17, 29.4%, p = 0.005). CONCLUSION: Severe hematologic disease in SLE has a high risk of relapse, which may be mitigated by the early institution of GC-sparing agents.

From first symptoms to diagnosis of systemic lupus erythematosus: mapping the journey of patients in an observational study.

OBJECTIVES: Although increased awareness for systemic lupus erythematosus (SLE) has reduced diagnostic delay, the average time from symptom onset to diagnosis is still long, potentially resulting in adverse outcomes. We mapped the journey of lupus patients from onset of symptoms to disease diagnosis. METHODS: We carried out an observational study of 275 SLE patients with disease duration <6 years. Data were collected from patient charts, interviews and in-person clinical visits. Total delay was divided in i) time from symptom onset to rst physician visit, ii) time from rst visit to assessment by rheumatologist, and iii) time from initial rheumatologist assessment to nal diagnosis. Early diagnosis was de ned as diagnosis within 6 months from symptom onset. RESULTS: Most common initial symptoms were arthritis/arthralgia (74.5%) and rashes (61.8%). Median (IQR) total delay between symptom onset and SLE diagnosis was 24 (54) months. An "early" diagnosis was achieved only in 28.4% of patients, while 55.6% were diagnosed after 12 months, with patients consulting an average of 3 different physicians before reaching diagnosis. Oral ulcers (OR 3.55; 95% CI 1.45-8.70) and malar rash (OR 1.99; 95% CI 1.00-3.94) as initial symptoms, and rst medical assessment by orthopaedic (OR 5.18; 95% CI 1.47-18.20) were independently associated with a delayed diagnosis. The latter was also associated with increased SDI at the time of diagnosis (OR 2.42; 95% CI 1.03-5.69), attributed mainly to neuropsychiatric and thrombotic events. CONCLUSIONS: Diagnosis of SLE is delayed by more than 6 months in three quarters of patients and is associated with more damage accrual.

Cross-species transcriptome analysis for early detection and specific therapeutic targeting of human lupus nephritis.

OBJECTIVES: Patients with lupus nephritis (LN) are in urgent need for early diagnosis and therapeutic interventions targeting aberrant molecular pathways enriched in affected kidneys. METHODS: We used mRNA-sequencing in effector (spleen) and target (kidneys, brain) tissues from lupus and control mice at sequential time points, and in the blood from 367 individuals (261 systemic lupus erythematosus (SLE) patients and 106 healthy individuals). Comparative cross-tissue and cross-species analyses were performed. The human dataset was split into training and validation sets and machine learning was applied to build LN predictive models. RESULTS: In murine SLE, we defined a kidney-specific molecular signature, as well as a molecular signature that underlies transition from preclinical to overt disease and encompasses pathways linked to metabolism, innate immune system and neutrophil degranulation. The murine kidney transcriptome partially mirrors the blood transcriptome of patients with LN with 11 key transcription factors regulating the cross-species active LN molecular signature. Integrated protein-to-protein interaction and drug prediction analyses identified the kinases TRRAP, AKT2, CDK16 and SCYL1 as putative targets of these factors and capable of reversing the LN signature. Using murine kidney-specific genes as disease predictors and machine-learning training of the human RNA-sequencing dataset, we developed and validated a peripheral blood-based algorithm that discriminates LN patients from normal individuals (based on 18 genes) and non-LN SLE patients (based on 20 genes) with excellent sensitivity and specificity (area under the curve range from 0.80 to 0.99). CONCLUSIONS: Machine-learning analysis of a large whole blood RNA-sequencing dataset of SLE patients using human orthologs of mouse kidney-specific genes can be used for early, non-invasive diagnosis and therapeutic targeting of LN. The kidney-specific gene predictors may facilitate prevention and early intervention trials.

Remission or low disease activity at pregnancy onset are linked to improved foetal outcomes in women with systemic lupus erythematosus: results from a prospective observational study.

OBJECTIVES: Systemic lupus erythematosus (SLE) patients show variably increased risk for pregnancy complications. We analysed pregnancy outcomes (foetal and maternal), patterns of disease activity and use of medications in a contemporary Caucasian SLE population. METHODS: Prospective observational study, involving hospital units and private rheumatologists in Greece, of incident pregnancies (period 2015-2018) in women with SLE. Clinical and obstetrical monitoring was performed at regular intervals up to 9 months post-partum. Regression and mixed model analyses were used to determine predictors for adverse foetal outcomes and flares. RESULTS: We monitored 82 pregnancies in 64 SLE patients. Foetal loss, prematurity and small for gestational age neonate occurred at 15.8%, 34.1% and 8.5%, respectively; 53.7% of pregnancies were complicated with at least one adverse outcome. Patients with antiphospholipid antibodies (aPL) had increased risk (odds ratio [OR] 5.67, p=0.015), whereas those at low disease activity at pregnancy onset were protected (OR 0.20, p=0.024) against foetal complications. Persistent activity and glucocorticoid intake during pregnancy also predicted poor foetal outcomes. SLE patients experienced an average 1.08 mild/moderate and 0.27 severe flares. The latter occurred more frequently post-partum, in patients with alopecia (OR 8.92, p=0.003), hypocomplementaemia (OR 10.34, p=0.038) and nephritis (OR 7.32, p=0.052). Lupusactivity post-labour was paralleled by decreased use of hydroxychloroquine, glucocorticoids and azathioprine. CONCLUSIONS: In SLE women, foetal complications are common especially in the presence of aPL and increased activity, which corroborates the importance of pregnancy planning and tight disease control at pregnancy onset. Flares, mostly mild or moderate, can occur both during and after pregnancy.

Tailored treatment strategies and future directions in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) represents a diagnostic and therapeutic challenge for physicians due to its protean manifestations and unpredictable course. The disease may manifest as multisystemic or organ-dominant and severity at presentation may vary according to age at onset (childhood-, adult- or late-onset SLE). Different manifestations may respond variably to different immunosuppressive medications and, even within the same organ-system, the severity of inflammation may vary from mild to organ-threatening. Current "state-of-the-art" in SLE treatment aims at remission or low disease activity in all organ systems. Apart from hydroxychloroquine and glucocorticoids (which should be used with caution), the choice of the appropriate immunosuppressive agent should be individualized and depend on the prevailing manifestation, severity stratification and patient childbearing potential. In this review, we provide an overview of therapeutic options for the various organ manifestations and severity patterns of the disease, different phenotypes (such as multisystem versus organ-dominant disease), as well as specific considerations, including lupus with antiphospholipid antibodies, childhood and late-onset disease, as well as treatment options during pregnancy and lactation.

Lupus or not? SLE Risk Probability Index (SLERPI): a simple, clinician-friendly machine learning-based model to assist the diagnosis of systemic lupus erythematosus.

OBJECTIVES: Diagnostic reasoning in systemic lupus erythematosus (SLE) is a complex process reflecting the probability of disease at a given timepoint against competing diagnoses. We applied machine learning in well-characterised patient data sets to develop an algorithm that can aid SLE diagnosis. METHODS: From a discovery cohort of randomly selected 802 adults with SLE or control rheumatologic diseases, clinically selected panels of deconvoluted classification criteria and non-criteria features were analysed. Feature selection and model construction were done with Random Forests and Least Absolute Shrinkage and Selection Operator-logistic regression (LASSO-LR). The best model in 10-fold cross-validation was tested in a validation cohort (512 SLE, 143 disease controls). RESULTS: A novel LASSO-LR model had the best performance and included 14 variably weighed features with thrombocytopenia/haemolytic anaemia, malar/maculopapular rash, proteinuria, low C3 and C4, antinuclear antibodies (ANA) and immunologic disorder being the strongest SLE predictors. Our model produced SLE risk probabilities (depending on the combination of features) correlating positively with disease severity and organ damage, and allowing the unbiased classification of a validation cohort into diagnostic certainty levels (unlikely, possible, likely, definitive SLE) based on the likelihood of SLE against other diagnoses. Operating the model as binary (lupus/not-lupus), we noted excellent accuracy (94.8%) for identifying SLE, and high sensitivity for early disease (93.8%), nephritis (97.9%), neuropsychiatric (91.8%) and severe lupus requiring immunosuppressives/biologics (96.4%). This was converted into a scoring system, whereby a score >7 has 94.2% accuracy. CONCLUSIONS: We have developed and validated an accurate, clinician-friendly algorithm based on classical disease features for early SLE diagnosis and treatment to improve patient outcomes.

Quality indicators for systemic lupus erythematosus based on the 2019 EULAR recommendations: development and initial validation in a cohort of 220 patients.

BACKGROUND: Quality of care is receiving increased attention in systemic lupus erythematosus (SLE). We developed quality indicators (QIs) for SLE based on the 2019 update of European League Against Rheumatism recommendations. METHODS: A total of 44 candidate QIs corresponding to diagnosis, monitoring and treatment, were independently rated for validity and feasibility by 12 experts and analysed by a modified Research and Development Corporation/University of California Los Angeles model. Adherence to the final set of QIs and correlation with disease outcomes (flares, hospitalisations and organ damage) was tested in a cohort of 220 SLE patients with a median monitoring of 2 years (IQR 2-4). RESULTS: The panel selected a total of 18 QIs as valid and feasible. On average, SLE patients received 54% (95% CI 52.3% to 56.2%) of recommended care, with adherence ranging from 44.7% (95% CI 40.8% to 48.6%) for diagnosis-related QIs to 84.3% (95% CI 80.6% to 87.5%) for treatment-related QIs. Sustained remission or low disease activity were achieved in 26.8% (95% CI 21.1% to 33.2%). Tapering of prednisone dose to less than 7.5 mg/day was achieved in 93.6% (95% CI 88.2% to 97.0%) while 73.5% (95% CI 66.6% to 79.6%) received the recommended hydroxychloroquine dose. Higher adherence to monitoring-related QIs was associated with reduced risk for a composite adverse outcome (flare, hospitalisation or damage accrual) during the last year of observation (OR 0.97 per 1% adherence rate, 95% CI 0.96 to 0.99). CONCLUSION: We developed QIs for assessing and improving the care of SLE patients. Initial real-life data suggest face validity, but a variable degree of adherence and a need for further improvement.

Demyelination with autoimmune features: a distinct clinical entity? Results from a longitudinal cohort.

OBJECTIVE: CNS demyelinating syndromes occurring in the context of SLE may represent a manifestation of neuropsychiatric lupus, or an overlap of SLE and multiple sclerosis (MS). We evaluated prospectively patients presenting with demyelinating syndrome for clinical and serological evidence of SLE and characterized the evolution of their clinical syndrome to a defined disease. METHODS: Patients with CNS demyelinating syndromes not fulfilling the criteria for MS were evaluated in a rheumatology unit for features of SLE and followed longitudinally (enrolment period 2016-20). Clinical, laboratory and neuroimaging data were recorded at every visit, following multidisciplinary evaluation. At end of follow-up, patients were assessed for their final neurological and rheumatological diagnosis, and classified accordingly. RESULTS: A total of 79 patients were included in the study [91.1% female, mean (s.d.) age at first demyelinating episode 38.4 (10.3) years, median (interquartile range) observation period 39 (57) months]. At last follow-up, 38 patients (48.1%) had evolved into MS. Of the remaining patients, 7 (17.1%) had SLE, while 34 (82.9%) had features of systemic autoimmunity without fulfilling classification criteria for SLE. The most common rheumatological features of these patients were inflammatory arthritis (73.5%), acute cutaneous lupus (47.1%) and positive ANA (72.1%). Importantly, these patients were less likely to have elevated IgG index (odds ratio 0.11, 95% CI 0.04, 0.32) and positive oligoclonal bands (odds ratio 0.21, 95% CI 0.08, 0.55). CONCLUSION: A significant number of patients with demyelination do not fulfill criteria for either MS or SLE at follow-up. These patients exhibit lupus-like autoimmune features and may represent a distinct entity, 'demyelination with autoimmune features'.

Transcriptome reprogramming and myeloid skewing in haematopoietic stem and progenitor cells in systemic lupus erythematosus.

OBJECTIVES: Haematopoietic stem and progenitor cells (HSPCs) are multipotent cells giving rise to both myeloid and lymphoid cell lineages. We reasoned that the aberrancies of immune cells in systemic lupus erythematosus (SLE) could be traced back to HSPCs. METHODS: A global gene expression map of bone marrow (BM)-derived HSPCs was completed by RNA sequencing followed by pathway and enrichment analysis. The cell cycle status and apoptosis status of HSPCs were assessed by flow cytometry, while DNA damage was assessed via immunofluorescence. RESULTS: Transcriptomic analysis of Lin-Sca-1+c-Kit+ haematopoietic progenitors from diseased lupus mice demonstrated a strong myeloid signature with expanded frequencies of common myeloid progenitors (CMPs)-but not of common lymphoid progenitors-reminiscent of a 'trained immunity' signature. CMP profiling revealed an intense transcriptome reprogramming with suppression of granulocytic regulators indicative of a differentiation arrest with downregulation trend of major regulators such as Cebpe, Cebpd and Csf3r, and disturbed myelopoiesis. Despite the differentiation arrest, frequencies of BM neutrophils were markedly increased in diseased mice, suggesting an alternative granulopoiesis pathway. In patients with SLE with severe disease, haematopoietic progenitor cells (CD34+) demonstrated enhanced proliferation, cell differentiation and transcriptional activation of cytokines and chemokines that drive differentiation towards myelopoiesis, thus mirroring the murine data. CONCLUSIONS: Aberrancies of immune cells in SLE can be traced back to the BM HSPCs. Priming of HSPCs and aberrant regulation of myelopoiesis may contribute to inflammation and risk of flare. TRIAL REGISTRATION NUMBER: 4948/19-07-2016.

In an early SLE cohort the ACR-1997, SLICC-2012 and EULAR/ACR-2019 criteria classify non-overlapping groups of patients: use of all three criteria ensures optimal capture for clinical studies while their modification earlier classification and treatment.

OBJECTIVES: Classification criteria are biased towards classifying long-standing disease. We compared the European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR)-2019, Systemic Lupus International Collaborating Clinics (SLICC)-2012 and ACR-1997 criteria in an early (median 48 months) systemic lupus erythematosus (SLE) cohort. METHODS: Patients diagnosed with SLE (n=690) or control diseases (n=401). Sensitivity, specificity of the criteria and time-to-classification were calculated. Modified classification algorithms were derived from a random 80% and validated in the remaining 20% of the dataset running multiple iterations. RESULTS: At last assessment, sensitivities of ACR-1997, SLICC-2012 and EULAR/ACR-2019 criteria were 85.7%, 91.3% and 88.6%, with specificities 93.0%, 93.8% and 97.3%, respectively. Both SLICC and EULAR/ACR enabled earlier classification. Only 76.7% of patients with SLE met all three criteria suggesting non-overlapping groups. Notably, unclassified patients had high prevalence of British Isles Lupus Assessment Group moderate/severe manifestations (43.3%-60%) and SLICC/ACR organ damage (30%-50%). At diagnosis, criteria missed 25.6%-30.5% of patients. Modification of EULAR/ACR and SLICC algorithms to include hypocomplementaemia and/or positive anti-phospholipid antibodies as alternative entry criterion, and/or allow classification with fewer clinical criteria from multiple organs, increased their sensitivity at diagnosis (median 82.0% and 86.2%) and overall (93.7% and 97.1%) with modest decreases in specificity. Importantly, patients who were still missed by the modified criteria had lower incidence of major organ involvement, use of immunosuppressive/biological therapies and organ damage. CONCLUSIONS: The SLICC and EULAR/ACR are more sensitive than the ACR and the EULAR/ACR criteria have superior specificity in early SLE, although patients with significant disease can be missed. Combination and/or modification of the classification algorithms may enhance their sensitivity, allowing earlier classification and treatment of more patients with high disease burden.

Update on the pathogenesis of central nervous system lupus.

PROPOSE OF REVIEW: Neuropsychiatric systemic lupus erythematosus (NPSLE) is an emerging frontier in lupus care encompassing a wide spectrum of clinical manifestations. Its pathogenesis remains poorly understood because of the complexity of pathophysiologic mechanisms involved and limited access to tissue. We highlight recent advances in the pathophysiology of neuropsychiatric lupus. RECENT FINDINGS: Disruption of blood-brain barrier (BBB) facilitating entrance of neurotoxic antibodies into the central nervous system (CNS), neuroinflammation and cerebral ischemia are the key mechanisms. Disruption of the BBB may occur not only at the traditional BBB, but also at the blood-cerebrospinal fluid barrier. Certain autoantibodies, such as anti-N-methyl-D-aspartate receptors, antiribosomal P and antiphospholipid antibodies may cause injury in subsets of patients with diffuse neuropsychiatric disease. Activation of microglia via autoantibodies, interferon-a or other immune reactants, may amplify the inflammatory response and promote neuronal damage. New inflammatory pathways, such as TWEAK/Fn14, Bruton's tyrosine kinase, Nogo-a and ACE may represent additional potential targets of therapy. Novel neuroimaging techniques suggest alterations in brain perfusion and metabolism, increased concentration of neurometabolites, indicative of glial activation, vasculopathy and neuronal impairment. SUMMARY: NPSLE encompasses a diverse phenotype with distinct pathogenic mechanisms, which could be targeted by novel therapies or repositioning of existing drugs.

Advances in the pharmacological management of systemic lupus erythematosus.

INTRODUCTION: Despite setbacks in clinical trials for systemic lupus erythematosus (SLE), three drugs have been approved for SLE and lupus nephritis (LN) treatment in the past decade. Several ongoing clinical trials, some viewed optimistically by the scientific community, underscore the evolving landscape. Emerging clinical data have established specific therapeutic targets in routine clinical practice for treating SLE, aiming to improve long-term outcomes. AREAS COVERED: Research related to treatment of SLE and LN is discussed, focusing on randomized clinical trials during the last 5 years and recommendations for the management of SLE published by the European Alliance of Associations for Rheumatology (EULAR), American College of Rheumatology (ACR), Asia Pacific League of Associations for Rheumatology (APLAR), and Pan-American League of Associations of Rheumatology (PANLAR). EXPERT OPINION: The landscape of SLE and LN treatments is evolving, as new drugs and combination treatment approaches redefine the traditional concepts of induction and maintenance treatment phases. As the therapeutic armamentarium in SLE continues to expand, the research focus is shifting from the imperative for new therapies to advancing our understanding of optimal treatment selection for individual patients, steering toward precision medicine strategies.

Interferon and B-cell Signatures Inform Precision Medicine in Lupus Nephritis.

Introduction: Current therapeutic management of lupus nephritis (LN) fails to induce long-term remission in over 50% of patients, highlighting the urgent need for additional options. Methods: We analyzed differentially expressed genes (DEGs) in peripheral blood from patients with active LN (n = 41) and active nonrenal lupus (n = 62) versus healthy controls (HCs) (n = 497) from the European PRECISESADS project (NTC02890121), and dysregulated gene modules in a discovery (n = 26) and a replication (n = 15) set of active LN cases. Results: Replicated gene modules qualified for correlation analyses with serologic markers, and regulatory network and druggability analysis. Unsupervised coexpression network analysis revealed 20 dysregulated gene modules and stratified the active LN population into 3 distinct subgroups. These subgroups were characterized by low, intermediate, and high interferon (IFN) signatures, with differential dysregulation of the "B cell" and "plasma cells/Ig" modules. Drugs annotated to the IFN network included CC-motif chemokine receptor 1 (CCR1) inhibitors, programmed death-ligand 1 (PD-L1) inhibitors, and irinotecan; whereas the anti-CD38 daratumumab and proteasome inhibitor bortezomib showed potential for counteracting the "plasma cells/Ig" signature. In silico analysis demonstrated the low-IFN subgroup to benefit from calcineurin inhibition and the intermediate-IFN subgroup from B-cell targeted therapies. High-IFN patients exhibited greater anticipated response to anifrolumab whereas daratumumab appeared beneficial to the intermediate-IFN and high-IFN subgroups. Conclusion: IFN upregulation and B and plasma cell gene dysregulation patterns revealed 3 subgroups of LN, which may not necessarily represent distinct disease phenotypes but rather phases of the inflammatory processes during a renal flare, providing a conceptual framework for precision medicine in LN.

Belimumab concentration measurements using a homologous anti-idiotype immunoassay.

Monitoring belimumab concentrations in patients can be a valuable tool for assessing treatment response and for personalizing drug doses. Various assay formats may be used to measure concentrations of therapeutic monoclonal antibodies. A particularly useful format involves the use of anti-idiotype monoclonal antibodies, selected to be highly specific to the antibody of interest. Here, we describe the development of a specific, high-affinity anti-idiotype antibody to belimumab, and the application of this antibody in a homologous sandwich ELISA to measure belimumab concentrations.