Immunopathogenesis of Juvenile Systemic Sclerosis

Spatial Transcriptomics Identifies Cellular and Molecular Characteristics of Scleroderma Skin Lesions: Pilot Study in Juvenile Scleroderma

Juvenile localized and systemic scleroderma are rare autoimmune diseases which cause significant disability and morbidity in children. The mechanisms driving juvenile scleroderma remain unclear, necessitating further cellular and molecular level studies. The Visium CytAssist spatial transcriptomics (ST) platform, which preserves the spatial location of cells and simultaneously sequences the whole transcriptome, was employed to profile the histopathological slides from skin lesions of juvenile scleroderma patients. (1) Spatial domains were identified from ST data and exhibited strong concordance with the pathologist's annotations of anatomical structures. (2) The integration of paired ST data and single-cell RNA sequencing (scRNA-seq) from the same patients validated the comparable accuracy of the two platforms and facilitated the estimation of cell type composition in ST data. (3) The pathologist-annotated immune infiltrates, such as perivascular immune infiltrates, were clearly delineated by the ST analysis, underscoring the biological relevance of the findings. This is the first study utilizing spatial transcriptomics to investigate skin lesions in juvenile scleroderma patients. The validity of the ST data was corroborated by gene expression analyses and the pathologist's assessments. Integration with scRNA-seq data facilitated the cell type-level analysis and validation. Analyses of immune infiltrates through combined ST data and pathological review enhances our understanding of the pathogenesis of juvenile scleroderma.

Orofacial Complications of the Connective Tissue Disease Systemic Sclerosis

Scleroderma (systemic sclerosis, SSc) is an autoimmune fibrosing connective tissue disease of unknown etiology. SSc patients show increased levels of autoantibodies, profibrotic cytokines, and extracellular matrix remodeling enzymes that collectively cause activated (myo)fibroblasts, the effector cell type of fibrosis. Despite these impacts, no disease-modifying therapy exists; individual symptoms are treated on a patient-to-patient basis. SSc research has been principally focused on symptoms observed in the lung and skin. However, SSc patients display significant oral complications that arise due to fibrosis of the not only skin, causing microstomia, but also the gastrointestinal tract, causing acid reflux, and the oral cavity itself, causing xerostomia and gingival recession. Due to these complications, SSc patients have impaired quality of life, including periodontitis, tooth loss, reduced tongue mobility, and malnutrition. Indeed, due to their characteristic oral presentation, SSc patients are often initially diagnosed by dentists. Despite their clinical importance, the oral complications of SSc are severely understudied; high-quality publications on this topic are scant. However, SSc patients with periodontal complications possess increased levels of matrix metalloproteinase-9 and chemokines, such as interleukin-6 and chemokine (C-X-C motif) ligand-4. Although many unsuccessful clinical trials, mainly exploring the antifibrotic effects of anti-inflammatory agents, have been conducted in SSc, none have used oral symptoms, which may be more amenable to anti-inflammatory drugs, as clinical end points. This review summarizes the current state of knowledge regarding oral complications in SSc with the goal of inspiring future research in this extremely important and underinvestigated area.

Cardiovascular risk and inflammation in a population with autoimmune diseases: a narrative review

Juvenile Systemic Connective Tissue Diseases (JSCTD) are a heterogeneous group of chronic autoimmune diseases, associated with dyslipidemia and increased cardiovascular risk are related. Studies from the last 10 years, from 2013 to 2022, on lipid profiles in JSCTD were collected. Different studies on lipid profiles in children affected by JSCTD were selected, because the aim is to analyze the cardiovascular risk and the possibility of atherosclerosis in these patients in whom, sometimes, corticosteroid therapies and immunosuppressants increase the state of dyslipidemia. Several studies have shown that autoimmune diseases with an inflammatory substrate also share abnormalities in lipid profile and increased cardiovascular risk. Specifically, associations have been found between Juvenile Systemic Connective Tissue Diseases and elevated triglycerides, TC-C (Total Cholesterol), LDL-C (Low-Density Lipoprotein), low HDL-C (High-Density Lipoprotein), and increased risk of developing diseases such as myocardial infarction, peripheral vascular disease, pulmonary and arterial hypertension, and atrial fibrillation. Supplementation with alpha-linolenic acid (ALA) on the other hand has also been analyzed with positive results in reducing inflammatory parameters, such as IL-6 (Interleukin-6), CRP (C-reactive protein), and fasting glucose, in subjects with dyslipidemia. These observations suggest that supplementation with ALA, an omega-3 precursor, may positively modulate both the inflammatory status and dyslipidemic conditions in patients with autoimmune disorders.

Clinical characteristics of juvenile systemic sclerosis in Korea: 31-year single-center study

Objective

To evaluate the clinical and laboratory characteristics, therapeutic drugs, and prognosis of juvenile systemic sclerosis (JSSc) at a single center in Korea.

Methods

This study was a retrospective analysis of patients with JSSc aged <16 years at disease onset and who were treated at our hospital between January 1992 and April 2023. All patients met the Pediatric Rheumatology European Society/American College of Rheumatology/European League against Rheumatism provisional classification criteria for JSSc, and those with localized scleroderma (morphea) were excluded.

Results

Among the 13 patients, proximal skin sclerosis (100%), Raynaud's phenomenon (RP) (84.6%), and sclerodactyly (69.2%) were present at the time of diagnosis. The most common symptom before diagnosis was RP, which was present in 10 patients (76.9%), whereas proximal skin sclerosis was observed in only five patients (38.5%). Thirteen patients had positive anti-nuclear antibody (ANA). At the time of diagnosis, five individuals had findings suggestive of interstitial lung disease (ILD) on a pulmonary function test (PFT) or chest computed tomography (CT), two of whom were asymptomatic. During follow-up, three patients developed ILD, one developed renal dysfunction, one developed heart disease, and none died.

Conclusion

This study was the first descriptive analysis of clinical features of JSSc in South Korea. Clinical suspicion is essential for diagnosing JSSc in patients with RP, especially if ANA is positive; however, proximal skin sclerosis, which is crucial for diagnosing JSSc, was unrecognized in the early phase of the disease. PFT should be considered even if a patient is asymptomatic or has normal chest CT.

Can vitamin D be an adjuvant therapy for juvenile rheumatic diseases?

Vitamin D, known for its essential role in calcium and bone homeostasis, has multiple effects beyond the skeleton, including regulation of immunity and modulation of autoimmune processes. Several reports have shown suboptimal serum 25 hydroxyvitamin D [25(OH)D] levels in people with different inflammatory and autoimmune rheumatic conditions, and an association between 25(OH)D levels, disease activity and outcomes. Although most available data pertain to adults, insights often are extended to children. Juvenile rheumatic diseases (JRDs) are a significant health problem during growth because of their complex pathogenesis, chronic nature, multisystemic involvement, and long-term consequences. So far, there is no definitive or clear evidence to confirm the preventive or therapeutic effect of vitamin D supplementation in JRDs, because results from randomized controlled trials (RCTs) have produced inconsistent outcomes. This review aims to explore and discuss the potential role of vitamin D in treating selected JRDs. Medline/PubMed, EMBASE, and Scopus were comprehensively searched in June 2023 for any study on vitamin D supplementary role in treating the most common JRDs. We used the following keywords: "vitamin D" combined with the terms "juvenile idiopathic arthritis", "juvenile systemic scleroderma", "juvenile systemic lupus erythematosus", "juvenile inflammatory myopathies", "Behcet disease", "periodic fever syndromes" and "juvenile rheumatic diseases". Observational studies have found that serum 25(OH)D concentrations are lower in juvenile idiopathic arthritis, juvenile systemic lupus erythematosus, juvenile systemic scleroderma, Behcet disease and proinflammatory cytokine concentrations are higher. This suggests that vitamin D supplementation might be beneficial, however, current data are insufficient to confirm definitively the complementary role of vitamin D in the treatment of JRDs. Considering the high prevalence of vitamin D deficiency worldwide, children and adolescents should be encouraged to supplement vitamin D according to current recommendations. More interventional studies, especially well-designed RCTs, assessing the dose-response effect and adjuvant effect in specific diseases, are needed to determine the potential significance of vitamin D in JRDs treatment.

Application and performance of disease activity indices proposed for patients with systemic sclerosis in an international cohort of patients with juvenile systemic sclerosis

Objectives

Juvenile systemic sclerosis is a rare childhood disease. Three disease activity indices have been published for adult patients with systemic sclerosis: the European Scleroderma Study Group Index, a modified version of the European Scleroderma Study Group Index and the revised European Scleroderma Trials and Research index. The objective of this study was to determine the feasibility and performance of the three disease activity indices in a prospectively followed cohort of patients with juvenile systemic sclerosis.

Methods

The analysis cohort was selected from the prospective international inception cohort enrolling juvenile systemic sclerosis patients. The correlation of the disease activity indices with the physicians' and the patients' global assessment of disease activity was determined. The disease activity indices were compared between patients with active and inactive disease. Sensitivity to change between 6- and 12-month follow-up was investigated by mixed models.

Results

Eighty percent of the 70 patients had a diffuse cutaneous subtype. The revised European Scleroderma Trials and Research index was highly correlated with the physician-reported global disease activity/parents-reported global disease activity (r = 0.74/0.64), followed by the European Scleroderma Study Group activity index (r = 0.61/0.55) and the modified version of the European Scleroderma Study Group activity index (r = 0.51/0.43). The disease activity indices significantly differed between active and inactive patients. The disease activity indices showed sensitivity to change between 6- and 12-month follow-up among patients who improved or worsened according to the physician-reported global disease activity and the parents-reported global disease activity.

Conclusion

Overall, no disease activity score is superior to the other, and all three scores have limitations in the application in juvenile systemic sclerosis patients. Furthermore, research on the concept of disease activity and suitable scores to measure disease activity in patients with juvenile systemic sclerosis is necessary in future.

Juvenile diabetes and systemic sclerosis: just a coincidence?

BACKGROUND

Limited joint mobility (LJM), previously known as cheiroarthropathy, refers to the presence of reduced extension at the finger joints in people with diabetes and may be associated with scleroderma-like syndromes such as diabetic sclerodactyly. While scleroderma-like syndromes and LJM have been observed in patients with long-term diabetes and associated complications, the coexistence of diabetes with Juvenile systemic sclerosis (jSSc) is rarely described.

CASE PRESENTATION

We describe the case of a 14-year-old boy with long-lasting type 1 diabetes (T1D) and suspected LJM associated with Raynaud phenomenon, sclerodactyly and tapering of the fingertips. A comprehensive work-up showed positive autoantibodies (ANA, anti-Ro-52, anti-Mi-2b), abnormal nailfold capillaroscopy with a scleroderma pattern, interstitial lung disease and cardiac involvement. The overall clinical picture was consistent with the diagnosis of jSSc.

CONCLUSIONS

LJM can be the initial sign of underlying systemic sclerosis. Nailfold capillaroscopy may help differentiate jSSc from classical LJM in pediatric patients with T1D and finger contractures or skin induration of no clear origin. This case report provides a starting point for a novel hypothesis regarding the pathogenesis of jSSc. The association between T1D and jSSc may be more than a coincidence and could suggest a relationship between glucose metabolism, fibrosis and microangiopathy.

Juvenile systemic sclerosis - observations of one clinical centre

OBJECTIVES

The systemic form of scleroderma (SSc) in children is a very rare disease; therefore, it is recognized relatively late, which increases the risk of complications. The aim of the study was to assess the clinical symptoms of juvenile systemic sclerosis (JSSc) in our cohort patients.

MATERIAL AND METHODS

A group of (N = 22) scleroderma patients aged between 2 and 16 years were observed. Demographic data and all clinical results obtained during 16 years of observation in the clinic of rheumatic diseases of developmental age were collected and analysed.

RESULTS

In all observed children the major JSSc criterion was found, i.e. skin thickening proximal to the metacarpal phalangeal and/or metatarsophalangeal joints. Other symptoms are presented as follows: nailfold capillary abnormalities - 100%, Raynaud's phenomenon - 90.9%, sclerodactyly - 27.3%, digital tip ulcers - 27.3%, dysphagia - 18.2%, gastroesophageal reflux - 27.3% (assessed in only 10 children), arrhythmias - 22.7%, heart failure - 9.1%, new-onset arterial hypertension - 9.1%, pulmonary fibrosis - 72.7%, pulmonary arterial hypertension - 9.1%, neuropathy - 13.6%, carpal tunnel syndrome - 4.5%, tendon friction rubs - 4.5%, arthritis - 22.7%, and myositis - 13.6%. There were no cases of renal crisis. Decreased diffusing capacity of oxygen was confirmed in 12 patients (58.3%). The presence of antinuclear antibodies was noticed in 86.7% of patients, and among SSc selective autoantibodies: anticentromere - 31.8%, anti-topoisomerase I - 18.2%, anti-PM-Scl 100 or 75 - 45.5%, anti-RP11, Th/To, PCNA in total in 27.3% were presented. In 4.5% of cases, apart from the presence of anti-PM-Scl autoantibodies, positive lupus band test, reduced concentration of complement, and antiphospholipid antibodies were also found. In 59% of studied children, the body mass index was below the 25th percentile.

CONCLUSIONS

The presented retrospective analysis shows that the occurrence of Raynaud's phenomenon with changes in nailfold capillaroscopy is the best screening toll for the assessment of risk of JSSc. All patients of developmental age with Raynaud's phenomenon, especially in the case of the appearance of antinuclear antibodies, should be monitored with capillaroscopy regardless of other laboratory or imaging tests.

Systemic sclerosis-associated pulmonary arterial hypertension in children

Systemic sclerosis (SSc) is a rare disease in childhood and is characterized by a combination of vasculopathy, inflammation, autoimmunity, and fibrogenesis with individually varying expression pattern. Pulmonary arterial hypertension (PAH) is a serious complication of SSc and affects approximately 10% of SSc patients. SSc-PAH is complex and difficult to diagnose, as symptoms are non-specific and may be complicated by other SSc-associated diseases such as interstitial lung disease or left heart disease. SSc-PAH patients can deteriorate rapidly, and disease progression can occur even in patients with mild PAH symptoms at diagnosis. Therefore, interdisciplinary care of SSc patients is essential, and treating physicians must be aware of the association between SSc and PAH. In order to detect PAH early, children with SSc should be regularly screened for PAH by pediatric cardiologists. If PAH is detected, a systematic diagnostic approach by trained PH specialists including careful phenotyping of PAH is required. Relevant interstitial lung disease and left heart disease should be ruled out in the differential diagnosis of SSc-PAH before starting any targeted therapy. Due to the progressive character of SSc-PAH known from adult studies, it appears appropriate to initiate targeted PAH-therapy in juvenile SSc-PAH early. Adapted from adult treatment algorithms, combination therapy regimens (addressing at least two pathophysiological pathways) are increasingly used for pediatric PAH patients, and there is growing evidence to support this approach also in SSc-PAH patients.

DNA methylation patterns in juvenile systemic sclerosis and localized scleroderma

Scleroderma refers to a group of chronic fibrotic immune-mediated diseases of unknown etiology. Characterizing epigenetic changes in childhood-onset scleroderma, systemic sclerosis or localized scleroderma, has not been previously performed. The aim of this study was to assess DNA methylation differences and similarities between juvenile systemic sclerosis (jSSc) and juvenile localized scleroderma (jLS) compared to matched healthy controls. Genome-wide DNA methylation changes in peripheral blood mononuclear cell samples were assessed using the MethylationEPIC array followed by bioinformatic analysis and limited functional assessment. We identified a total of 105 and 144 differentially methylated sites compared to healthy controls in jSSc and jLS, respectively. The majority of differentially methylated sites and genes represented were unique to either jSSc or jLS suggesting a different underlying epigenetic pattern in both diseases. Among shared differentially methylated genes, methylation levels in a CpG site in FGFR2 can distinguish between LS and healthy PBMCs with a high accuracy. Canonical pathway analysis revealed that inflammatory pathways were enriched in genes differentially methylated in jSSc, including STAT3, NF-κB, and IL-15 pathways. In contrast, the HIPPO signaling pathway was enriched in jLS. Our data also suggest a potential role for NOTCH3 in both jSSc and jLS, and revealed a number of transcription factors unique to each of the two diseases. In summary, our data revealed important insights into jSSc and jLS and suggest a potentially novel epigenetic diagnostic biomarker for LS.

Early detection of ventricular dysfunction in juvenile systemic sclerosis by speckle tracking echocardiography

OBJECTIVE

Cardiac involvement is the most important cause of mortality in juvenile systemic sclerosis (JSSc). Recent reports in adult patients underline that traditional techniques of imaging are inadequate to assess the subclinical cardiac involvement, while speckle tracking echocardiography (STE) is able to identify ventricular dysfunctions in the early stages. The aim of our study was to assess the role of STE in JSSc.

METHODS

Demographic, clinical and laboratory data were collected from patients with JSSc. Cardiac investigations performed at baseline (T0) and 18 (T18) and 36 months (T36) follow-up included electrocardiography, conventional echocardiography with measurement of the ejection fraction (EF) and STE with assessment of left and right ventricular global longitudinal strain (LV-GLS and RV-GLS). Cardiac parameters have been compared with demographic characteristics and disease severity, assessed by the Juvenile Systemic Sclerosis Severity Score (J4S).

RESULTS

A total of 18 patients, 12 (67%) females, entered the study. At T0, electrocardiography was abnormal in three patients, EF was reduced in one, LV-GLS was abnormal in three (16.7%) and RV-GLS was abnormal in five (27.8%). At T18, EF remained stable while at T36 the result decreased in seven of nine patients. At the same time, LV-GLS also worsened (from -21.6% to -18.2%, P = 0.01). LV-GLS and RV-GLS at baseline showed a significant correlation with J4S (P = 0.012 and P = 0.02, respectively).

CONCLUSION

STE is more sensitive than standard echocardiography to identify cardiac involvement in JSSc. Over time, we observed a gradual worsening of LV-GLS, a sign of left ventricular dysfunction, that anticipated by several months the decrease of EF.

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.

The Role of Cutaneous Type I IFNs in Autoimmune and Autoinflammatory Diseases

IFNs are well known as mediators of the antimicrobial response but also serve as important immunomodulatory cytokines in autoimmune and autoinflammatory diseases. An increasingly critical role for IFNs in evolution of skin inflammation in these patients has been recognized. IFNs are produced not only by infiltrating immune but also resident skin cells, with increased baseline IFN production priming for inflammatory cell activation, immune response amplification, and development of skin lesions. The IFN response differs by cell type and host factors and may be modified by other inflammatory pathway activation specific to individual diseases, leading to differing clinical phenotypes. Understanding the contribution of IFNs to skin and systemic disease pathogenesis is key to development of new therapeutics and improved patient outcomes. In this review, we summarize the immunomodulatory role of IFNs in skin, with a focus on type I, and provide insight into IFN dysregulation in autoimmune and autoinflammatory diseases.

Treatment in Juvenile Scleroderma

PURPOSE OF REVIEW

Treatment of scleroderma in children is challenging since little is known about its pathogenesis. Herein, we review the most recent evidence regarding the treatment of juvenile scleroderma.

RECENT FINDINGS

According to the recent recommendations for Pediatric Rheumatology in Europe (SHARE), systemic treatment in localized scleroderma is needed when there is a risk for disability, such as in generalized or pansclerotic morphea and progressive linear scleroderma. In juvenile systemic sclerosis, the introduction of the severity score, J4S, has standardized the assessment of the patients in the daily practice and allowed a more tailored therapeutic approach. Since, to date, no clinical trial is available in JSSc, due to its rarity, the treatment is based on adults' experience. The recent recommendations for juvenile scleroderma represent an important instrument to standardize the treatment approach, confirm the role of methotrexate, and open new windows for effective experimental treatments, such as mycophenolate mofetil and biological agents, for severe or refractory cases.