Pulmonary arterial hypertension (PAH) complicates the course of systemic sclerosis (SSc) and is associated with poor prognosis. The elevation of systolic pulmonary arterial pressure (sPAP) during exercise in patients with SSc with normal resting haemodynamics may anticipate the development of PAH. Exercise echocardiography (ExEcho) has been proposed as a useful technique to identify exercise-induced increases in sPAP, but it is unclear how to clinically interpret these findings. In this systematic review, we summarize the available evidence on the role of exercise echocardiography to estimate exercise-induced elevations in pulmonary and left heart filling pressures in patients with systemic sclerosis. We conducted a systematic review of the literature using MEDLINE, Cochrane Library and Web of Knowledge, using the vocabulary terms: (‘systemic sclerosis’ OR ‘scleroderma’) AND (‘exercise echocardiography’) AND (‘pulmonary hypertension’). Studies including patients with SSc without a prior diagnosis of PAH, and subjected to exercise echocardiography were included. All searches were limited to English and were augmented by review of bibliographic references from the included studies. The quality of evidence was assessed by the Effective Public Health Practice Project system. We identified 15 studies enrolling 1242 patients, who were mostly middle-aged and female. Several exercise methods were used (cycloergometer, treadmill and Master’s two step), with different protocols and positions (supine, semi-supine, upright); definition of a positive test also varied widely. Resting estimated sPAP levels varied from 18 to 35 mm Hg, all in the normal range. The weighted means for estimated sPAP were 22.2 ± 2.9 mmHg at rest and 43.0 ± 4.3 mmHg on exercise; more than half of the studies reported mean exercise sPAP ≥40 mmHg. The assessment of left ventricular diastolic function on peak exercise was reported in a minority of studies; however, when assessed, surrogate variables of left ventricular (LV) diastolic dysfunction were associated with higher sPAP on exercise. We found very high heterogeneity in the methods, the protocols and the estimated sPAP response to exercise. LV diastolic dysfunction was common and was associated with greater elevation of sPAP on exercise.

Systemic sclerosis (SSc) is an immune-mediated disease wherein T cells are particularly implicated, presenting a poor prognosis and limited therapeutic options. Thus, mesenchymal-stem/stromal-cell (MSC)-based therapies can be of great benefit to SSc patients given their immunomodulatory, anti-fibrotic, and pro-angiogenic potential, which is associated with low toxicity. In this study, peripheral blood mononuclear cells from healthy individuals (HC, n = 6) and SSc patients (n = 9) were co-cultured with MSCs in order to assess how MSCs affected the activation and polarization of 58 different T cell subsets, including Th1, Th17, and Treg. It was found that MSCs downregulated the activation of 26 out of the 41 T cell subsets identified within CD4⁺, CD8⁺, CD4⁺CD8⁺, CD4⁻CD8⁻, and γδ T cells in SSc patients (HC: 29/42) and affected the polarization of 13 out of 58 T cell subsets in SSc patients (HC: 22/64). Interestingly, SSc patients displayed some T cell subsets with an increased activation status and MSCs were able to downregulate all of them. This study provides a wide-ranging perspective of how MSCs affect T cells, including minor subsets. The ability to inhibit the activation and modulate the polarization of several T cell subsets, including those implicated in SSc’s pathogenesis, further supports the potential of MSC-based therapies to regulate T cells in a disease whose onset/development may be due to immune system’s malfunction.

Spondyloarthritis (SpA) is a heterogeneous immune-mediated disease family with axial and entheseal predilection, substantial morbidity, and socioeconomic burden. This chapter synthesizes current evidence on SpA immunobiology, mechanisms of tissue damage, the gut-joint axis, and vitamin D, and outlines therapeutic implications. Genetic susceptibility intersects with innate and adaptive immunity to drive type-3 cytokine programs dominated by IL-17, with contributions from TNF and JAK/STAT signalling. Structural injury follows a reproducible sequence of bone-marrow osteitis, reparative fat tissue, and endochondral new bone, modulated by angiogenesis and osteo-stromal pathways, explaining the coexistence of erosion and aberrant ossification and supporting early, sustained inflammation control to prevent syndesmophytes. Mucosal immunology adds an upstream layer with barrier dysfunction and microbial metabolites calibrating dendritic-cell priming and Th17 response. However, taxon-level causality is limited and interventional results are mixed. Vitamin D deficiency is common and merits correction for skeletal health, but disease-modifying effects in SpA are unproven. Clinically, TNF and IL-17 inhibition are treatment mainstays for axial disease, whereas IL-23 blockade underperforms; JAK inhibitors broaden options. Future priorities include biomarker-guided stratification, longitudinal multi-omics integrated with imaging, and rational combinations coupling effective immune-targeted agents with barrier or metabolite-focused adjuncts to improve outcomes and prevent structural progression.

Background: Autoantibodies are central to the diagnosis and risk stratification of systemic sclerosis (SSc), but their prevalence and clinical associations may vary across populations. This study aimed to evaluate the prevalence and immuno-clinical associations of different autoantibodies in the Rheumatic Diseases Portuguese Register systemic sclerosis cohort. Methods: This was a multicentre observational registry-based study that used data from the Reuma.pt SSc module. Patients were divided according to autoantibody status, and associations between autoantibody expression and clinical data were assessed using appropriate statistical tests, with Bonferroni correction applied for multiple comparisons. Multivariable binary logistic regression was performed for clinically relevant outcomes, with adjustment for sex, age at diagnosis and disease duration. Results: A total of 1080 patients were included, 87.5% female, with a mean age at last evaluation of 60.2 ± 14.6 years and a mean disease duration of 12.4 ± 10.0 years. Limited cutaneous SSc was the most frequent clinical category (57.4%), followed by diffuse cutaneous SSc (17.7%), very early diagnosis of systemic sclerosis (VEDOSS; 12.3%), overlap syndromes (9.8%) and SSc sine scleroderma (2.8%). Antinuclear antibodies were present in 93.4% of patients. Anti-centromere antibodies (ACAs) were the most frequent SSc-specific autoantibodies (54.6%), followed by topoisomerase I antibodies (ATAs; 21.8%). ACA positivity was associated with limited cutaneous disease; older age at diagnosis; and lower frequency of interstitial lung disease (ILD), myositis and flexion contractures. ATA positivity was associated with diffuse cutaneous disease, male sex, higher modified Rodnan skin score (mRSS), digital ulcers, flexion contractures, oesophageal involvement and ILD. Among less frequent autoantibodies, anti-Pm/Scl antibodies were associated with myositis, joint involvement, calcinosis and ILD; anti-U1RNP antibodies with younger age, MCTD overlap, myositis and joint involvement; anti-RNA polymerase III antibodies (ARAs) with scleroderma renal crisis and higher mRSS; anti-U3RNP antibodies with diffuse cutaneous disease and renal involvement; and anti-Ku antibodies with overlap syndromes. Conclusions: In this large real-world SSc cohort, autoantibody status was strongly associated with distinct clinical phenotypes, confirming its value for disease stratification. While most established immuno-clinical associations were reproduced, some differences from international cohorts were observed, supporting the need for population-specific validation of autoantibody associations in SSc.