Microbiota and arthritis: cause or consequence?

The relationship between intestinal microbiota and arthritis has garnered significant attention, with emerging evidence suggesting a potential association between dysbiosis and various forms of inflammatory arthropathies. While observational studies have provided valuable insights into microbiota alterations in patients with arthritis, establishing causality remains challenging. Observational data, influenced by multiple confounders such as environmental factors, medication effects, and dietary habits, are insufficient to conclusively determine whether microbiota changes are somehow causally linked to arthritis. The heterogeneity of results across independent studies further complicates interpretation. To further support this hypothesis, interventional randomised trials are deemed necessary, yet their implementation in this area presents significant technical limitations. Experimental animal models offer insights into potential pathogenic mechanisms linking dysbiosis to arthritis, including compromised intestinal barrier function, the role of microbiota-derived metabolites and molecular mimicry. However, conflicting findings underscore the complexity of hostmicrobiota interactions and the challenges in establishing causality.Efforts to modulate the microbiota for arthritis treatment or prevention have shown promise, yet efficacy and applicability remains uncertain. Antibacterial drugs, dietary interventions, probiotics, and faecal microbiota transplantation have been explored, but their clinical utility awaits further validation. In conclusion, while the association between intestinal microbiota and arthritis is increasingly recognised, establishing causality remains elusive.

The Effect of JAK Inhibitors on Patient-Reported Outcomes in Psoriatic Arthritis.

Objective: Psoriatic arthritis (PsA) is a chronic inflammatory disease that affects the joints and skin of patients with psoriasis. In this review we aimed to summarise the available evidence regarding the effect of Janus kinase inhibitors (JAKi) on patient-reported outcomes (PROs) when used for the management of PsA. Methods: We utilised a narrative review approach as we searched the available literature for articles to be included in our study. Results: JAKi have been found to be effective in inducing better PRO responses compared to placebo. These findings have been consistent across various patient populations, including those with active PsA, those with an inadequate response to conventional therapies, and those with comorbidities. The evidence supporting the benefits of JAKi on PROs in PsA is compelling, demonstrating consistent improvements in pain, physical function, fatigue, and quality of life. Conclusion: Numerous studies have demonstrated the the efficacy of JAKi in improving PROs in patients with PsA.

Primary Sjögren's syndrome in Italy: Real-world evidence of a rare disease through administrative healthcare data.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is a systemic autoimmune disease with significant impact on morbidity, mortality, and quality of life. This study aimed to evaluate epidemiology, healthcare needs and related costs of pSS patients from the Italian National Health Service perspective. METHODS: From the Fondazione Ricerca e Salute's database (∼5 million inhabitants/year), pSS prevalence in 2018 was calculated. Demographics, mean healthcare consumptions and direct costs at one year following index date (first in-hospital diagnosis/disease waiver claim) were analysed through an individual direct matched pair case-control analysis (age, sex, residency). RESULTS: In Italy, 3.8/10,000 inhabitants were identified as affected by pSS (1,746 case: 1,746 controls) in 2018. In the year following index date, 53.7% of cases and 42.7% of controls received ≥1 drug (p<0.001); mean per capita cost was €501 and €161, respectively (p<0.01). At least one hospitalization occurred to 7.8% of cases and 3.9% of controls (p<0.001) with mean per capita costs of €416 and €129, respectively (p = 0.46). At least one outpatient specialist service was performed in 49.8% of cases and 30.6% of controls (p<0.001); mean per capita costs were €200 and €75, respectively (p<0.01). Overall, mean annual costs were €1,171 per case and €372 per control (p < 0.01). CONCLUSION: According to results of this population-based study, the prevalence of pSS in Italy appears to be consistent with the definition of rare disease. Patients with pSS have higher pharmacological, in-hospital and outpatient specialist care needs, leading to three-times higher overall cost for the INHS, compared to the general population.

Large-scale DNA sequencing identifies rare variants associated with Systemic Lupus Erythematosus susceptibility in known risk genes.

The identification of rare genetic variants associated to Systemic Lupus Erythematosus (SLE) could also help to understand the pathogenic mechanisms at the basis of the disease. In this study we have analyzed a cohort of 200 Italian SLE patients in order to explore the rare protein-coding variants in five genes (TNFAIP3, STAT4, IL10, TRAF3IP2, and HCP5) already investigated for commons variants found associated in our previous studies. Genomic DNA of 200 SLE patients was sequenced by whole exome sequencing. The identified variants were filtered by frequency and evaluated by in silico predictions. Allelic association analysis was performed with standard Fisher's exact test. Introducing a cutoff at MAF < 0.01, a total of 19 rare variants were identified. Seven of these variants were ultra-rare (MAF < 0.001) and six were absent in the GnomAD database. For TNFAIP3 gene, the variant c.A1939C was observed in 4 SLE patients and it is located in a region enriched in phosphorylation sites and affects the predict affinity of specific kinases. In TRAF3IP2 gene, we observed 5 different rare variants, including the novel variant c.G410A, located in the region that mediates interaction with TRAF6, and therefore a possible risk factor for SLE development. In STAT4 gene, we identified 6 different rare variants. Among these, three missense variants decrease the stability of this protein. Moreover, 3 novel rare variants were detected in 3 SLE patients. In particular, c.A767T variant was predicted as damaging by six prediction tools. Concluding, we have observed that even in genes whose common variability is associated with SLE susceptibility, it is possible to identify rare variants that could have a strong effect in the disease development and could therefore allow a better understanding of the functional domain involved.

Exploring the Link between Plasma Levels of PCSK9, Immune Dysregulation and Atherosclerosis in Patients with Primary Sjögren's Syndrome.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) regulates lipid metabolism contributing to cardiovascular (CV) risk in the general population. The relationship between PCSK9 and CV risk in systemic autoimmune diseases has been poorly explored. We investigated the association between plasma PCSK9, measures of immune-inflammatory status and markers of atherosclerosis in 52 consecutive patients with primary Sjögren's syndrome (pSS) in comparison to healthy controls (HCs). Median plasma PCSK9 levels were significantly higher in pSS patients versus HCs (162 (79-255) vs. 53 (39-99) ng/mL). Significantly higher prevalence of subclinical atherosclerosis and lower of dyslipidaemia (61% vs. 85%, p = 0.042) characterized pSS patients versus HCs. In pSS, no significant correlation emerged between PCSK9 and disease activity, atherosclerosis and lipid levels. In HCs, PCSK9 significantly correlated with lipid levels and atherosclerosis. Interestingly, significantly higher PCSK9 levels were found in HCs with high-to-very-high as compared to low-to-moderate CV risk (p = 0.018) while a non-significant trend towards higher PCSK9 levels was detected in pSS patients with low-to-moderate as compared to high-to-very-high CV risk (p = 0.060). This is the first demonstration that pSS patients, despite lower prevalence of dyslipidaemia and higher CV risk profile, are characterized by a 3-fold increase in PCSK9 levels in comparison to HCs. As PCSK9 does not correlate with measures of CV risk, its role in CV morbidity in pSS needs further investigation.

Organ damage in Systemic Lupus Erythematosus patients: A multifactorial phenomenon.

The prevention of chronic damage, especially in early disease phases, remains an unmet need in the management of Systemic Lupus Erythematous (SLE) patients, despite the application of a so-called treat-to-target strategy. The high proportion of SLE patients developing chronic damage suggests a multifactorial aetiology. Thus, besides disease activity, other factors may contribute to the development of damage. The revision of data published so far underlines that, next to disease activity, it is possible to identify other factors playing a relevant role in damage development and progression. In summary, the presence of antiphospholipid antibodies and drugs used to treat SLE patients, in particular glucocorticoids, is strongly associated with SLE-related damage. Furthermore, recent data suggests the possible role of genetic background in determining the development of specific organ damage, in particular renal and neurological. Nonetheless, demographic factors, such as age, sex and disease duration could exert a role along with the presence of comorbidities. The contribution of different factors in determining damage development suggests the need for new outcomes to assess a comprehensive disease control including not only the assessment of disease activity, but also the evaluation of chronic damage development.

PCSK3 Overexpression in Sjögren's Syndrome Patients May Be Regulated by rs4932178 SNP in Its Promoter Region and Correlates with IFN-γ Gene Expression.

BACKGROUND: The PCSK3 gene encodes for the protease enzyme Furin, which promotes proteolytic maturation of important regulators of the immune response, and also enhances the secretion of interferon-γ (IFN). Several studies have suggested its possible involvement in the pathogenesis of chronic inflammatory diseases. METHODS: We investigated the PCSK3 gene expression level in peripheral blood mononuclear cells isolated from Sjögren's Syndrome (SS) patients and healthy controls and we evaluated a possible correlation with IFN-γ gene expression. Moreover, we also explored the variability of two PCSK3 genetic polymorphisms (rs4932178 and rs4702) to evaluate a possible association between these polymorphisms and the expression levels of this gene. RESULTS: We observed, by RT-qPCR, that the PCSK3 expression level was significantly higher in SS patients compared to the controls (p = 0.028), and we confirmed a positive correlation between PCSK3 and IFN-γ expression levels (p < 0.001). Moreover, we reported that the variant homozygous genotype of rs4932178 SNP is associated with a higher expression of the PCSK3 gene (p = 0.038) and with the SS susceptibility (p = 0.016). CONCLUSIONS: Our data suggest that Furin could play a role in SS development, also promoting IFN-γ secretion.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) in Autoimmune Rheumatic and Non Rheumatic Diseases.

The soluble urokinase plasminogen activator receptor (suPAR) is the bioactive form of uPAR, a membrane-bound glycoprotein, and it is primarily expressed on the surface of immunologically active cells. Mirroring local inflammation and immune activation, suPAR has gained interest as a potential prognostic biomarker in several inflammatory diseases. Indeed, in many diseases, including cancer, diabetes, cardiovascular diseases, kidney diseases, and inflammatory disorders, higher suPAR concentrations have been associated with disease severity, disease relapse, and mortality. Our review describes and discusses the supporting literature concerning the promising role of suPAR as a biomarker in different autoimmune rheumatic and non-rheumatic diseases.

Circulating Calprotectin (cCLP) in autoimmune diseases.

BACKGROUND AND AIM: Calprotectin (CLP) is a heterodimeric complex formed by two S100 proteins (S100A8/A9), which plays a pivotal role in innate immunity. Due to its intrinsic cytotoxic and proinflammatory properties, CLP controls cell differentiation, proliferation and NETosis and has been associated with a wide range of rheumatic diseases. Our review summarizes the widespread interest in circulating CLP (cCLP) as a biomarker of neutrophil-related inflammation, in autoimmune rheumatic disease (ARD) and non-ARD. METHODS: A thorough literature review was performed using PubMed and EMBASE databases searching for circulating calprotectin and synonyms S100A8/A9, myeloid-related protein 8/14 (MRP8/MRP14), calgranulin A/B and L1 protein in addition to specific ARDs and autoimmune non-rheumatic diseases. We selected only English-language articles and excluded abstracts without the main text. RESULTS: High cCLP serum levels are associated with worse structural outcomes in rheumatoid arthritis and to a lesser extent, in spondyloarthritis. In addition, cCLP can predict disease relapse in some autoimmune diseases including systemic lupus erythematosus (SLE), anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) and some severe manifestations of connective tissue diseases, such as glomerulonephritis in SLE, AAV, juvenile idiopathic arthritis, adult-onset Still's disease and lung fibrosis in systemic sclerosis. Therefore, cCLP levels enable the identification of patients who need an accurate and tight follow-up. The clinical usefulness of cCLP as an inflammatory marker has been suggested for inflammatory/autoimmune non-rheumatic diseases, and especially for the monitoring of the inflammatory bowel diseases patients. Currently, there are only a few studies that evaluated the cCLP efficacy as a clinical biomarker in inflammatory/autoimmune non-rheumatic diseases with controversial results. Future studies are warranted to better clarify the role of cCLP in relation to the disease severity in myasthenia gravis, multiple sclerosis, chronic inflammatory demyelinating polyneuropathy, Graves' orbitopathy, autoimmune bullous diseases and uveitis. CONCLUSION: Our literature review supports a relevant role of cCLP as potential prognostic biomarker mirroring local or systemic inflammation, especially in chronic inflammatory rheumatic diseases.

JAK inhibitors and autoimmune rheumatic diseases.

The four Janus kinase (JAK) proteins and the seven Signal Transducers of Activated Transcription (STAT) mediate intracellular signal transduction downstream of cytokine receptors, which are involved in the pathology of allergic, autoimmune, and inflammatory diseases. The development of targeted small-molecule treatments with diverse selective inhibitory profiles, such as JAK inhibitors (JAKi), has supported an important change in the treatment of multiple disorders. Indeed, JAKi inhibit intracellular signalling controlled by numerous cytokines implicated in the disease process of rheumatoid arthritis and several other inflammatory and immune diseases. Therefore, JAKi have the capacity to target multiple pathways of those diseases. Other autoimmune diseases treated with JAKi include systemic sclerosis, systemic lupus erythematosus, dermatomyositis, primary Sjogren's syndrome, and vasculitis. In all of these cases, innate immunity stimulation activates adaptive immunity, resulting in the production of autoreactive T cells as well as the stimulation and differentiation of B cells. Mechanism-based treatments that target JAK-STAT pathways have the possibility of improving outcomes by reducing the consumption of glucocorticoids and/or non-specific immunosuppressive drugs in the management of systemic immune-mediated inflammatory diseases.

Polyangiitis overlap syndrome: a rare clinical entity.

Polyangiitis overlap syndrome is a rare clinical entity comprising patients with overlapping features of more than one vasculitis, usually eosinophilic granulomatosis with polyangiitis (EGPA) and granulomatosis with polyangiitis (GPA). Few cases of polyangiitis overlap syndrome have been described in the literature, mostly associated with c-ANCA, anti-proteinase (PR)-3 positivity, a protean clinical picture characterized by vasculitis, eosinophilia and eosinophilic infiltrates in tissues and a favorable response to steroids and immunosuppressant treatments. Herein, we present a case of a 66-year-old woman with nasal obstruction, external nose deformity, sensorineural hearing loss, peripheral blood eosinophilia, high titer anti-PR3 antibodies and lung involvement. Nasal septum biopsies showed inflammatory infiltrate with eosinophilic component; histopathology of the lung demonstrated necrotizing granulomas associated with inflammatory infiltrate composed of numerous neutrophils and some eosinophils. The patient was diagnosed with polyangiitis overlap syndrome and successfully treated with cyclophosphamide. Recognizing this entity is fundamental given the distinct clinical phenotype and outcomes to therapy in the complex scenario of ANCA-associated vasculitides.

Predictors of complete 24-month remission and flare in patients with polymyalgia rheumatica.

To date, few papers investigated the predictive factors of sustained 24-month remission and of flare in patients with polymyalgia rheumatica (PMR). We retrospectively evaluated clinical charts from PMR patients. Patients were evaluated at baseline, at 1 month, 3 months and subsequently at 6, 12 and 24 months. We analyzed the differences between patients who achieved remission within 6 months of diagnosis, those who achieved remission at 24 months, and patients who did not. Among 137 patients, 57 (41.6%) achieved remission at 6 months and complete remission at 24 months was achieved by 104 patients (75.9%). The erythrocyte sedimentation rate at baseline was higher in patients who did not achieve remission than in patients who achieved it (p = 0.012). Female patients were less likely to achieve complete remission (45/68, 66.2% vs. 59/69, 85.5%, p = 0.01) compared to males. Fifty-four patients (39.4%) experienced at least one flare. Patients who did not achieve sustained complete remission suffered a flare more often (22/39 vs. 32/98, p = 0.01) and earlier than patients who did (10.33 ± 7.89 months vs. 13.64 ± 6.97 months, p = 0.011). Multivariate analysis confirmed that female sex (RR = 3.2, 95% CI 1.3-7.9) and higher baseline prednisone dosage (RR = 1.1, 95% CI 1.007-1.109) were negative independent predictors of complete remission at 24 months. A significant percentage of patients with PMR requires prolonged steroid treatment and may experience flares at 24 months of follow-up. Female sex and higher baseline prednisone dosage are negative independent predictors of complete remission at 24 months.

How Has Molecular Biology Enhanced Our Undertaking of axSpA and Its Management.

PURPOSE: This review aims at investigating pathophysiological mechanisms in spondyloarthritis (SpA). Analysis of genetic factors, immunological pathways, and abnormalities of bone metabolism lay the foundations for a better understanding of development of the axial clinical manifestations in patients, allowing physician to choose the most appropriate therapeutic strategy in a more targeted manner. RECENT FINDINGS: In addition to the contribution of MHC system, findings emerged about the role of non-HLA genes (as ERAP1 and 2, whose inhibition could represent a new therapeutic approach) and of epigenetic mechanisms that regulate the expression of genes involved in SpA pathogenesis. Increasing evidence of bone metabolism abnormalities secondary to the activation of immunological pathways suggests the development of various bone anomalies that are present in axSpA patients. SpA are a group of inflammatory diseases with a multifactorial origin, whose pathogenesis is linked to the genetic predisposition, the action of environmental risk factors, and the activation of immune response. It is now well known how bone metabolism leads to long-term structural damage via increased bone turnover, bone loss and osteoporosis, osteitis, erosions, osteosclerosis, and osteoproliferation. These effects can exist in the same patient over time or even simultaneously. Evidence suggests a cross relationship among innate immunity, autoimmunity, and bone remodeling in SpA, making treatment approach a challenge for rheumatologists. Specifically, treatment targets are consistently increasing as new drugs are upcoming. Both biological and targeted synthetic drugs are promising in terms of their efficacy and safety profile in patients affected by SpA.

Treatment with COLchicine in hospitalized patients affected by COVID-19: The COLVID-19 trial.

OBJECTIVE: To evaluate whether the addition of colchicine to standard of care (SOC) results in better outcomes in hospitalized patients with COVID-19. DESIGN: This interventional, multicenter, randomized, phase 2 study, evaluated colchicine 1.5 mg/day added to SOC in hospitalized COVID-19 patients (COLVID-19 trial) and 227 patients were recruited. The primary outcome was the rate of critical disease in 30 days defined as need of mechanical ventilation, intensive care unit (ICU), or death. RESULTS: 152 non-anti-SARS-CoV-2-vaccinated patients (colchicine vs controls: 77vs75, mean age 69.1±13.1 vs 67.9±15 years, 39% vs 33.3% females, respectively) were analyzed. There was no difference in co-primary end-points between patients treated with colchicine compared to controls (mechanical ventilation 5.2% vs 4%, ICU 1.3% vs 5.3%, death 9.1% vs 6.7%, overall 11 (14.3%) vs 10 (13.3%) patients, P=ns, respectively). Mean time to discharge was similar (colchicine vs controls 14.1±10.4 vs 14.7±8.1 days). Older age (>60 years, P=0.025), P/F<275 mmHg (P=0.005), AST>40 U/L (P<0.001), pre-existent heart (P=0.02), lung (P=0.003), upper-gastrointestinal (P=0.014), lower-gastrointestinal diseases (P=0.009) and cancer (P=0.008) were predictive of achieving the primary outcome. Diarrhoea (9.1% vs 0%, p=0.0031) and increased levels of AST at 6 days (76.9±91.8 vs 33.5±20.7 U/l, P=0.016) were more frequent in the colchicine group. CONCLUSION: Colchicine did not reduce the rate and the time to the critical stage. Colchicine was relatively safe although adverse hepatic effects require caution. We confirm that older (>60 years) patients with comorbidities are characterized by worse outcome.

Sjögren's syndrome: one year in review 2022.

Primary Sjögren's syndrome (pSS) is a complex disabling systemic autoimmune disorder. The hallmark of pSS is the T-cell-mediated hyperactivation of B-cells, evolving from asymptomatic conditions to systemic complications and lymphoma development. On tissue level, the typical feature is the lymphocytic infiltration of the salivary gland by B-, T- and antigen presenting cells, as mirrored by the diagnostic cornerstone role of minor salivary gland (MSG) biopsy. B-cells show multiple possible roles in disease pathogenesis, from autoantibody production, to antigen presentation, and cytokine production. B-cells hyperactivation is supported by genetic risk factors, T-cell dependent and independent mechanisms, and the presence of different pathogenic B-cell subsets must be reminded.Many aspects have been investigated in the last year regarding genetic and epigenetics, B- and T-cell role in pSS pathogenesis, their interaction with salivary gland epithelial cells (SGECs) and in their direct or indirect use as biomarkers and predictors of disease development, activity, and lymphomagenesis.In this review, following the others of this series, we will summarise the most recent literature on pSS pathogenesis and clinical features focusing in particular on new insights into pSS molecular stratification and therapeutic advances in the era of precision medicine.