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.

Sjögren's syndrome: one year in review 2023.

Primary Sjögren's syndrome (pSS) is a systemic autoimmune disorder characterised by the T-cell-mediated hyperactivation of B-cells and cytokine production. The condition may evolve from an asymptomatic, indolent course, with glandular involvement, to extra-glandular systemic manifestations up to 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. Recently, increasing research focused on the investigation of mechanisms underlying the complex pathogenesis of the disease and highlighted the multi-factorial nature of SS consisting of concomitant involvement of environmental, genetic, neuroendocrine and immune factors. In particular, many aspects have been investigated regarding genetic and epigenetics, the role of specific B- and T-cell phenotypes and the investigation of disease-specific biomarkers as predictors of disease development, activity, and lymphomagenesis. Surely, a deeper understanding of these multiple mechanisms may facilitate earlier diagnosis, enable subphenotyping of patients and open novel therapeutic possibilities to address the unmet needs of the disease in the upcoming years.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.

Rituximab for rapidly progressive juvenile systemic sclerosis.

OBJECTIVE: Juvenile systemic sclerosis (JSSc) with rapidly progressive course is a life-threatening condition associated with a poor prognosis. Recently, rituximab (RTX) has been shown to be a promising treatment for adult patients with SSc. We present a series of four patients with rapidly progressive JSSc successfully treated with RTX. METHODS: Clinical, laboratory and functional parameters were collected from four patients with rapidly progressive JSSc treated with RTX for at least 1 year. All patients underwent four yearly courses of i.v. RTX 375 mg/m2 on day 0 and 14, at 3-month intervals. Low dose oral prednisone and MMF were also administered. Data were recorded at baseline and every 6 months and included pulmonary and myocardial function parameters, muscular, vascular and skin changes. The Juvenile Systemic Sclerosis Severity Score (J4S) estimated the overall disease severity over time. RESULTS: Four patients (three males, one female), aged 8-17 years, entered the study. Three patients presented with prevalent cardiac involvement, one with severe pulmonary involvement. After 1 year of RTX treatment, all patients showed significant improvement of J4S, Raynaud's phenomenon and cutaneous involvement. Among those with prevalent cardiac involvement, two showed an improvement of the myocardial function (left ventricular ejection fraction [EF] +37% and +19%, respectively) and in the third arrhythmias disappeared. The patient with severe pulmonary involvement showed a significant improvement of the respiratory function (forced vital capacity +46%, forced expiratory volume in 1 s +33%, diffusing capacity of the lung for carbon monoxide [DLCO] +30%). No major side effects were reported. CONCLUSIONS: Our data suggest that a combination of RTX and MMF is effective in arresting the rapid progression of JSSc.