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.

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.

A network-based approach reveals long non-coding RNAs associated with disease activity in lupus nephritis: key pathways for flare and potential biomarkers to be used as liquid biopsies.

Objective: A blood-based biomarker is needed to assess lupus nephritis (LN) disease activity, minimizing the need for invasive kidney biopsies. Long non-coding RNAs (lncRNAs) are known to regulate gene expression, appear to be stable in human plasma, and can serve as non-invasive biomarkers. Methods: Transcriptomic data of whole blood samples from 74 LN patients and 20 healthy subjects (HC) were analyzed to identify differentially expressed (DE) lncRNAs associated with quiescent disease and flares. Weighted gene co-expression network analysis (WGCNA) was performed to uncover lncRNAs with a central role (hub lncRNAs) in regulating key biological processes that drive LN disease activity. The association of hub lncRNAs with disease activity was validated using RT-qPCR on an independent cohort of 15 LN patients and 9 HC. cis- and trans-targets of validated lncRNAs were explored in silico to examine potential mechanisms of their action. Results: There were 444 DE lncRNAs associated with quiescent disease and 6 DE lncRNAs associated with flares (FDR <0.05). WGCNA highlighted IFN signaling and B-cell activity/adaptive immunity as the most significant processes contributing to nephritis activity. Four disease-activity-associated lncRNAs, namely, NRIR, KLHDC7B-DT, MIR600HG, and FAM30A, were detected as hub genes and validated in an independent cohort. NRIR and KLHDC7B-DT emerged as potential key regulators of IFN-mediated processes. Network analysis suggests that FAM30A and MIR600HG are likely to play a central role in the regulation of B-cells in LN through cis-regulation effects and a competing endogenous RNA mechanism affecting immunoglobulin gene expression and the IFN-λ pathway. Conclusions: The expression of lncRNAs NRIR, KLHDC7B-DT, FAM30A, and MIR600HG were associated with disease activity and could be further explored as blood-based biomarkers and potential liquid biopsy on LN.

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.

Combined - whole blood and skin fibroblasts- transcriptomic analysis in Psoriatic Arthritis reveals molecular signatures of activity, resistance and early response to treatment.

Background: An interplay between immune cells and resident skin and joint stromal cells is implicated in psoriatic arthritis (PsA), yet the mechanisms remain elusive with a paucity of molecular biomarkers for activity and response. Combined transcriptomic and immunophenotypic analysis of whole blood and skin fibroblasts could provide further insights. Methods: Whole blood RNA-seq was performed longitudinally in 30 subjects with PsA at the beginning, one and six months after treatment, with response defined at six months. As control groups, 10 healthy individuals and 10 subjects with rheumatoid arthritis (RA) were recruited combined with public datasets from patients with psoriasis (PsO) and systemic lupus erythematous (SLE). Differential expression analysis and weighted gene co-expression network analysis were performed to identify gene expression signatures, while deconvolution and flow cytometry to characterize the peripheral blood immune cell profile. In a subset of affected and healthy individuals, RNA-seq of skin fibroblasts was performed and subjected to CellChat analysis to identify the blood-skin fibroblast interaction network. Results: PsA demonstrated a distinct "activity" gene signature in the peripheral blood dominated by TNF- and IFN-driven inflammation, deregulated cholesterol and fatty acid metabolism and expansion of pro-inflammatory non-classical monocytes. Comparison with the blood transcriptome of RA, PsO, and SLE revealed a "PsA-specific signature" enriched in extracellular matrix remodeling. This was further supported by the skin fibroblast gene expression profile, displaying an activated, proliferating phenotype, and by skin-blood interactome analysis revealing interactions with circulating immune cells through WNT, PDGF and immune-related semaphorins. Of note, resistance to treatment was associated with upregulation of genes involved in TGFß signaling and angiogenesis and persistent increase of non-classical monocytes. Differentially expressed genes related to platelet activation and hippo signaling discriminated responders and non-responders as early as one month after treatment initiation. Conclusion: Transcriptome analysis of peripheral blood and skin fibroblasts in PsA reveals a distinct disease activity signature and supports the involvement of skin fibroblasts through their activation and interaction with circulating immune cells. Aberrant TGFß signaling and persistently increased non-classical monocytes characterize treatment-resistant PsA, with pro-inflammatory pathways related to platelet activation and Hippo signaling predicting early response to treatment.

First Diagnosis of Systemic Lupus Erythematosus in Hospitalized Patients: Clinical Phenotypes and Pitfalls for the Non-Specialist.

BACKGROUND: Prompt recognition of systemic lupus erythematosus (SLE) in hospitalized patients presenting with severe disease is essential to initiate treatment. We sought to characterize the phenotype of hospitalized patients with new-onset SLE and estimate potential diagnostic delays. METHODS: An observational study of 855 patients ("Attikon" SLE cohort). Clinical phenotype was categorized according to the leading manifestation that led to hospitalization. Disease features, time to diagnosis, classification criteria, and the SLE Risk Probability Index (SLERPI) were recorded for each patient. RESULTS: There were 191 patients (22.3% of the total cohort) hospitalized due to manifestations eventually attributed to SLE. Main causes of admission were neuropsychiatric syndromes (21.4%), cytopenias (17.8%), nephritis (17.2%), and thrombotic events (16.2%). Although 79.5% of patients were diagnosed within 3 months from hospitalization, in 39 patients diagnosis was delayed, particularly in those with hematological manifestations. At hospitalization, a SLERPI >7 (indicating high probability for SLE) was found in 87.4% of patients. Patients missed by the SLERPI had fever, thrombotic or neuropsychiatric manifestations not included in the algorithm. Lowering the SLERPI threshold to 5 in patients with fever or thrombotic events increased the diagnostic rate from 88.8% to 97.9% in this subgroup, while inclusion of all neuropsychiatric events yielded no additional diagnostic value. CONCLUSION: One in five patients with new-onset SLE manifest disease presentations required hospitalization. Although early diagnosis was achieved in the majority of cases, in approximately 20%, diagnosis was delayed. A lower SLERPI cut-off (≥5) in patients with fever or thrombosis could enhance early diagnosis.

Interstitial Pneumonia with Autoimmune Features (IPAF): A Single-Centre, Prospective Study.

OBJECTIVES: Interstitial pneumonia with autoimmune features (IPAF) refers to patients with interstitial lung disease and autoimmune features not fulfilling the classification criteria for a specific connective tissue disease. We sought to study the characteristics, disease progression, response to treatment and complications of patients with IPAF in 1-year follow-up period. METHODS: Clinical and laboratory findings, comorbidities, medications, pulmonary function tests (PFTs), chest HRCT and complications during the one-year follow-up period were documented for each of the 39 enrolled patients with IPAF. RESULTS: The mean age at the time of IPAF diagnosis was 63.2 (±11) years, and 62% of patients were female. The most common clinical features were arthritis (82%) and rash (54%-not included in the IPAF criteria). Antinuclear antibodies (ANA) (59%) and non-specific interstitial pneumonia (NSIP-61.5%) were the most prevalent autoantibodies and radiological pattern respectively. PFTs at 12 months from baseline stabilized or improved in 79.5% of patients (p> 0.05). Infections were observed in 23.1% of patients during the first and in 12.8% during the second semester of follow-up. Two patients (5.1%) required hospitalization. All infections occurred in patients with non-usual interstitial pneumonia (UIP) pattern (p=0.02). CONCLUSIONS: Arthritis and rash are among the most common features in IPAF suggesting rash could be included into IPAF criteria. Almost 80% of patients had stable/improved PFTs at the end of follow-up. Infections occurred mainly in the first semester of treatment and in patients with non-UIP radiological pattern probably due to higher doses of corticosteroids used in these patients.

Transition to severe phenotype in systemic lupus erythematosus initially presenting with non-severe disease: implications for the management of early disease.

OBJECTIVE: Changes in the care of patients with SLE dictate a re-evaluation of its natural history and risk factors for disease deterioration and damage accrual. We sought to decipher factors predictive of a deterioration in phenotype ('transition') in patients initially presenting with non-severe disease. METHODS: Patients from the 'Attikon' cohort with disease duration ≥1 year were included. Disease at diagnosis was categorised as mild, moderate or severe, based on the British Isles Lupus Assessment Group manifestations and physician judgement. 'Transition' in severity was defined as an increase in category of severity at any time from diagnosis to last follow-up. Multivariable logistic regression was performed to identify baseline factors associated with this transition. RESULTS: 462 patients were followed for a median (IQR) of 36 (120) months. At diagnosis, more than half (56.5%) had a mild phenotype. During disease course, transition to more severe forms was seen in 44.2%, resulting in comparable distribution among severity patterns at last follow-up (mild 28.4%, moderate 33.1%, severe 38.5%). Neuropsychiatric involvement at onset (OR 6.33, 95% CI 1.22 to 32.67), male sex (OR 4.53, 95% CI 1.23 to 16.60) and longer disease duration (OR 1.09 per 1 year, 95% CI 1.04 to 1.14) were independently associated with transition from mild or moderate to severe disease. Patients with disease duration ≥3 years who progressed to more severe disease had more than 20-fold increased risk to accrue irreversible damage. CONCLUSION: Almost half of patients with initially non-severe disease progress to more severe forms of SLE, especially men and patients with positive anti-double-stranded DNA or neuropsychiatric involvement at onset. These data may have implications for the management of milder forms of lupus.