Urine proteomic signatures of histological class, activity, chronicity, and treatment response in lupus nephritis.

Lupus nephritis (LN) is a pathologically heterogenous autoimmune disease linked to end-stage kidney disease and mortality. Better therapeutic strategies are needed as only 30%-40% of patients completely respond to treatment. Noninvasive biomarkers of intrarenal inflammation may guide more precise approaches. Because urine collects the byproducts of kidney inflammation, we studied the urine proteomic profiles of 225 patients with LN (573 samples) in the longitudinal Accelerating Medicines Partnership in RA/SLE cohort. Urinary biomarkers of monocyte/neutrophil degranulation (i.e., PR3, S100A8, azurocidin, catalase, cathepsins, MMP8), macrophage activation (i.e., CD163, CD206, galectin-1), wound healing/matrix degradation (i.e., nidogen-1, decorin), and IL-16 characterized the aggressive proliferative LN classes and significantly correlated with histological activity. A decline of these biomarkers after 3 months of treatment predicted the 1-year response more robustly than proteinuria, the standard of care (AUC: CD206 0.91, EGFR 0.9, CD163 0.89, proteinuria 0.8). Candidate biomarkers were validated and provide potentially treatable targets. We propose these biomarkers of intrarenal immunological activity as noninvasive tools to diagnose LN and guide treatment and as surrogate endpoints for clinical trials. These findings provide insights into the processes involved in LN activity. This data set is a public resource to generate and test hypotheses and validate biomarkers.

Clinical and histological features of patients with primary Sjögren's syndrome and autoimmune thyroiditis: a national multicentre cross-sectional study.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is frequently associated with autoimmune thyroiditis (AT). The aim of this study was to evaluate the prevalence of AT in a national cohort of pSS and to describe the clinical and histological phenotype of patients with pSS and associated AT. METHODS: In this multicentre cross-sectional study, data from 2546 pSS were collected and the presence of AT was reported. In a subgroup, the histology of minor salivary glands was evaluated. Differences between pSS with and without AT were evaluated. RESULTS: A concomitant pSS and AT was detected in 19.6% of cases. Patients with pSS and AT displayed a lower prevalence of lymphoma, male sex and disease-modifying anti-rheumatic drugs (DMARDs) use and a higher prevalence of fibromyalgia, coeliac disease and hypergammaglobulinaemia. Multivariable analysis confirmed a higher prevalence of fibromyalgia and coeliac disease and lower use of DMARDs. In a subgroup of patients (n=232), a significantly higher focus score and number of foci was detected in pSS without AT (n=169) as compared to pSS with AT (n=54). CONCLUSIONS: This is the largest study evaluating the coexistence of pSS and AT. We confirm a high association between pSS and AT and describe the presence of a different phenotype characterized by a higher rate of celiac disease and fibromyalgia. Although not significant, the lower prevalence of both lymphoma and intake of DMARDs, along with a significantly lower focus score and number of foci, possibly suggest a more favourable outcome in concomitant pSS and AT which further deserve future investigations.

Citrullinated and carbamylated proteins in extracellular microvesicles from plasma of patients with rheumatoid arthritis.

OBJECTIVES: To investigate the expression of citrullinated and carbamylated proteins in extracellular microvesicles (EMVs) from RA patients. METHODS: We enrolled 24 RA naïve for biological therapy and 20 healthy donors (HD), matched for age and sex. For each patient, laboratory and clinical data were recorded and clinical indexes were measured (Clinical Disease Activity Index, Simplified Disease Activity Index, DAS28). EMVs in RA patients and HD were purified from plasma and measured by nanoparticle tracking analysis (NanoSight). Further, EMVs were incubated with anti-citrullinated/carbamylated proteins antibodies and processed by flow cytometry and western blot to evaluate the expression of citrullinated/carbamylated antigens. RESULTS: NanoSight revealed a significant increase of EMVs in RA compared with HD. Moreover, cytofluorimetric analysis showed a significative higher expression of citrullinated antigens on EMVs' surface in RA than donors, while no substantial difference was found in the expression of carbamylated antigens. These data were confirmed by western blot which identified vimentin, glycolytic enzyme alpha-enolase 1 and collagen type II as the main citrullinated and carbamylated proteins carried by EMVs. Finally, a relevant correlation between the expression of citrullinated antigens and disease activity was found. CONCLUSIONS: The results of this study suggest an involvement of EMVs in the pathogenesis of RA by inducing autoimmunity.

Alternative exon usage in TRIM21 determines the antigenicity of Ro52/TRIM21 in systemic lupus erythematosus.

The origin and mechanisms of autoantigen generation in systemic lupus erythematosus (SLE) are poorly understood. Here, we identified SLE neutrophils activated in vivo by IFN as a prominent source of Ro52, also known as tripartite motif-containing protein 21 (TRIM21), a critical autoantigen historically thought to be primarily generated by keratinocytes in SLE. Different from mononuclear cells and keratinocytes, SLE neutrophils are enriched in several unique Ro52 species containing a core sequence encoded by exon 4 (Ro52Ex4) in TRIM21. Ro52Ex4 is the main target of anti-Ro52 antibodies and is found in 2 Ro52 variants (Ro52α and a potentially novel isoform termed Ro52γ) upregulated in SLE neutrophils. Further analysis of Ro52γ revealed a subset of autoantibodies against a unique C-terminal domain (Ro52γCT) generated from a frameshift due to the lack of exon 6 in Ro52γ. Antibodies to Ro52Ex4 and Ro52γCT distinguish SLE patient subsets characterized by distinct clinical, laboratory, treatment, and transcriptional profiles that are not discerned by the "classical" anti-Ro52 antibodies. These studies uncover IFN-activated neutrophils as a key source of unique immunogenic forms of Ro52 in SLE. Moreover, the finding of Ro52Ex4 and Ro52γCT as core targets of anti-Ro52 antibodies focus interest on Ro52γ as the potential isoform toward which immunological tolerance is initially lost in SLE.

Autophagy Hijacking in PBMC From COVID-19 Patients Results in Lymphopenia.

Autophagy is a homeostatic process responsible for the self-digestion of intracellular components and antimicrobial defense by inducing the degradation of pathogens into autophagolysosomes. Recent findings suggest an involvement of this process in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the role of autophagy in the immunological mechanisms of coronavirus disease 2019 (COVID-19) pathogenesis remains largely unexplored. This study reveals the presence of autophagy defects in peripheral immune cells from COVID-19 patients. The impairment of the autophagy process resulted in a higher percentage of lymphocytes undergoing apoptosis in COVID-19 patients. Moreover, the inverse correlation between autophagy markers levels and peripheral lymphocyte counts in COVID-19 patients confirms how a defect in autophagy might contribute to lymphopenia, causing a reduction in the activation of viral defense. These results provided intriguing data that could help in understanding the cellular underlying mechanisms in COVID-19 infection, especially in severe forms.

Autophagy in Rheumatic Diseases: Role in the Pathogenesis and Therapeutic Approaches.

Autophagy is a lysosomal pathway for the degradation of damaged proteins and intracellular components that promotes cell survival under specific conditions. Apoptosis is, in contrast, a critical programmed cell death mechanism, and the relationship between these two processes influences cell fate. Recent evidence suggests that autophagy and apoptosis are involved in the self-tolerance promotion and in the regulatory mechanisms contributing to disease susceptibility and immune regulation in rheumatic diseases. The aim of this review is to discuss how the balance between autophagy and apoptosis may be dysregulated in multiple rheumatic diseases and to dissect the role of autophagy in the pathogenesis of rheumatoid arthritis, systemic lupus erythematosus, and Sjögren's syndrome. Furthermore, to discuss the potential capacity of currently used disease-modifying antirheumatic drugs (DMARDs) to target and modulate autophagic processes.

Maladaptive Autophagy in the Pathogenesis of Autoimmune Epithelitis in Sjögren's Syndrome.

OBJECTIVE: Salivary gland epithelial cells (SGECs) are key cellular drivers in the pathogenesis of primary Sjögren's syndrome (SS); however, the mechanisms sustaining SGEC activation in primary SS remain unclear. We undertook this study to determine the role of autophagy in the survival and activation of SGECs in primary SS. METHODS: Primary SGECs isolated from the minor SGs of patients with primary SS or sicca syndrome were evaluated by flow cytometry, immunoblotting, and immunofluorescence to assess autophagy (autophagic flux, light chain 3 IIB [LC3-IIB], p62, LC3-IIB+/lysosome-associated membrane protein 1 [LAMP-1] staining), apoptosis (annexin V/propidium iodide [PI], caspase 3), and activation (intercellular adhesion molecule, vascular cell adhesion molecule). Focus score and germinal center presence were assessed in the SGs from the same patients to assess correlation with histologic severity. Human SG (HSG) cells were stimulated in vitro with peripheral blood mononuclear cells (PBMCs) and serum from primary SS patients in the presence or absence of autophagy inhibitors to determine changes in autophagy and epithelial cell activation. RESULTS: SGECs from primary SS patients (n = 24) exhibited increased autophagy (autophagic flux [P = 0.001]; LC3-IIB [P = 0.02]; p62 [P = 0.064]; and as indicated by LC3-IIB/LAMP-1+ staining), increased expression of antiapoptotic molecules (Bcl-2 [P = 0.006]), and reduced apoptosis (annexin V/PI [P = 0.002]; caspase 3 [P = 0.057]), compared to samples from patients with sicca syndrome (n = 16). Autophagy correlated with histologic disease severity. In vitro experiments on HSG cells stimulated with serum and PBMCs from primary SS patients confirmed activation of autophagy and expression of adhesion molecules, which was reverted upon pharmacologic inhibition of autophagy. CONCLUSION: In primary SS SGECs, inflammation induces autophagy and prosurvival mechanisms, which promote SGEC activation and mirror histologic severity. These findings indicate that autophagy is a central contributor to the pathogenesis of primary SS and a new therapeutic target.

Comprehensive disease control in systemic lupus erythematosus.

OBJECTIVES: We evaluated a monocentric SLE cohort in order to assess the frequency of Lupus comprehensive disease control (LupusCDC), a condition defined by the achievement of remission and the absence of damage progression. METHODS: Our longitudinal analysis included SLE patients with 5-years follow-up and at least one visit per year. Disease activity was assessed by SLE Disease Activity Index 2000 (SLEDAI-2K) and three different remission levels were evaluated (Complete Remission, CR; Clinical remission off-corticosteroids; clinical remission on-corticosteroids). Chronic damage was assessed according to SLICC Damage Index (SDI). LupusCDC was defined as remission achievement for at least one year plus absence of chronic damage progression in the previous one year. A machine learning based analysis was carried out, applying and comparing Nonlinear Support Vector Machines (SVM) models and Decision Trees (DT), whereas features ranking was performed with the ReliefF algorithm. RESULTS: We evaluated 172 patients [M/F 16/156, median age 49 years (IQR 16.7), median disease duration 180 months (IQR 156)]. SDI values (baseline mean±SD 0.7 ± 1.1) significantly increased during the follow-up period. In all time-points analyzed, LupusCDC including CR was the most frequently detected. The failure to reach this condition was significantly associated with renal involvement and with the intake of immunosuppressant drugs and glucocorticoid (GC). Ten patients (5.8%) have maintained LupusCDC during the whole 5-year follow-up: these patients had never presented renal involvement and showed lower prevalence of anti-phospholipid antibodies (p = 0.0001). Finally, the prevalence of GC intake was significantly lower (p = 0.0001). The application of machine learning models showed that the available features were able to provide significant information to build predictive models with an AUC score of 0.703 ± 0.02 for DT and 0.713 ± 0.02 for SVM. CONCLUSIONS: Our data on a monocentric cohort suggest that the LupusCDC can efficaciously merge into one outcome SLE-related disease activity and chronic damage in order to perform an all-around evaluation of SLE patients.

"Protenuria in SLE: Is it always lupus?"

Proteinuria is one of the most typical manifestations of kidney involvement in Systemic Lupus Erythematosus (SLE). We report the case of a 23-year-old woman with a 6-year-long history of SLE presenting with proteinuria after a three-year remission on hydroxychloroquine. Kidney histological examination showed alterations inconsistent with lupus nephritis and suggestive of hydroxychloroquine toxicity or Fabry disease. The latter was confirmed by genetic assay.

Up-regulation of autophagy by etanercept treatment results in TNF-induced apoptosis reduction in EA.hy926 endothelial cell line.

OBJECTIVES: Rheumatoid arthritis (RA) is an autoimmune systemic inflammatory disease associated with a high prevalence of atherosclerosis. Endothelial dysfunction has emerged as a potentially valuable prognostic tool in predicting the development of atherosclerosis. Tumour necrosis factor (TNF) is the main cytokine involved in RA pathogenesis, exerting a pro-atherogenic role. TNF-inhibitors are effective treatments in RA, also improving endothelial function. Regarding this, no experimental data are known about the involvement of etanercept. We investigated the contribution of TNF to endothelial dysfunction and the effect of in vitro treatment with etanercept, with a special focus on autophagy and apoptosis pathways. METHODS: Autophagy and apoptosis were evaluated by Western blot and flow cytometry in EA.hy926 endothelial cells treated with TNF alone or in combination with etanercept for 24h. RESULTS: Blocking autophagy, TNF was able to induce endothelial cell apoptosis. Co-treatment with etanercept reverted this effect, up-regulating the autophagy pathway. CONCLUSIONS: Our results confirm the protective role of etanercept, by restoring autophagy on TNF-induced endothelial damage.

Homocysteinylated alpha 1 antitrypsin as an antigenic target of autoantibodies in seronegative rheumatoid arthritis patients.

Rheumatoid arthritis (RA) is a chronic autoimmune disease and rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA) are the most frequently detected autoantibodies (autoAbs). To date, more than 20% of RA cases are still defined as seronegative forms (seronegative RA, SN-RA). The aim of this study was to identify new antigenic targets of autoAbs in RA patients, which can also be recognized in SN-RA. Using a proteomic approach, we tested sera from SN-RA patients by analyzing synovial fluid (SF) proteins from these patients. Sera from SN-RA patients revealed a strong reactive spot, corresponding to alpha 1 antitrypsin (A1AT). Reverse-phase nanoliquid chromatography and tandem mass spectrometry (Matrix Assisted Laser Desorption/Ionization-Time Of Flight, MALDI-TOF/TOF) confirmed the presence of A1AT in SF and showed that homocysteinylation was one of the post-translational modifications of A1AT. Homocysteinylated (Hcy)-A1AT immunoprecipitated from SN-RA patients' SFs and in vitro modified Hcy-A1AT were used as antigens by Enzyme-Linked ImmunoSorbent Assay (ELISA) to test the presence of specific autoAbs in sera from 111 SN-RA patients, 132 seropositive (SP)-RA patients, and from 95 patients with psoriatic arthritis, 40 patients with osteoarthritis, and 41 healthy subjects as control populations. We observed that a large portion of SN-RA patients (75.7%), and also most of SP-RA patients' sera (87.1%) displayed anti-Hcy-A1AT autoAbs (anti-HATA). Native A1AT was targeted at a lower rate by SP-RA patients autoAbs, while virtually no SN-RA patients' sera showed the presence of anti-native A1AT autoAbs. In conclusion, anti-HATA can be considered potential biomarkers for RA, also in the SN forms. The discovery of novel autoAbs targeting specific autoantigens can represent higher clinic significance for all RA patients' population.

Autophagy Modulation in Lymphocytes From COVID-19 Patients: New Therapeutic Target in SARS-COV-2 Infection.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the novel coronavirus, causing coronavirus disease 2019 (COVID-19). During virus infection, several pro-inflammatory cytokines are produced, leading to the "cytokine storm." Among these, interleukin (IL)-6, tumor necrosis factor-α (TNF-α), and IL-1ß seem to have a central role in the progression and exacerbation of the disease, leading to the recruitment of immune cells to infection sites. Autophagy is an evolutionarily conserved lysosomal degradation pathway involved in different aspects of lymphocytes functionality. The involvement of IL-6, TNF-α, and IL-1ß in autophagy modulation has recently been demonstrated. Moreover, preliminary studies showed that SARS-CoV-2 could infect lymphocytes, playing a role in the modulation of autophagy. Several anti-rheumatic drugs, now proposed for the treatment of COVID-19, could modulate autophagy in lymphocytes, highlighting the therapeutic potential of targeting autophagy in SARS-CoV-2 infection.

A new T2 lesion in a patient with the clinically isolated syndrome does not necessarily imply a conversion to multiple sclerosis.

In the follow-up of patients with the clinically isolated syndrome, both clinical and MRI findings should be carefully evaluated by clinicians to avoid misinterpretation and inappropriate diagnosis of multiple sclerosis. We describe a case of a patient with a previous diagnosis of clinically isolated syndrome who developed a new asymptomatic brain lesion at the MRI follow-up. The careful evaluation of clinical history and radiological findings allowed the correct diagnosis of cocaine-associated ischemic stroke. Our case highlights that, in patients with the clinically isolated syndrome, the appearance of a new lesion on MRI does not necessarily imply a conversion to multiple sclerosis. Among "better explanations", ischemic lesions are of relevance and, in patients without typical risk factors for stroke, rarer causes such as cocaine assumption should be considered.