Transplantation of in vitro prefabricated adipose organoids attenuates skin fibrosis by restoring subcutaneous fat and inducing dermal adipogenesis.

Localized scleroderma is a complex autoimmune disease characterized by dermal fibrosis and loss of cutaneous fat. While cytotherapy offers a promising treatment option, stem cell transplantation results in low survival rates and fails in target cell differentiation. In this study, we aimed to prefabricate syngeneic adipose organoids (ad-organoids) using microvascular fragments (MVFs) via three-dimensional (3D) culturing and transplant them beneath the fibrotic skin to restore subcutaneous fat and reverse the pathological manifestation of localized scleroderma. We employed 3D culturing of syngeneic MVFs with stepwise angiogenic and adipogenic induction to produce ad-organoids and evaluated their microstructure and paracrine function in vitro. C57/BL6 mice with induced skin scleroderma were treated with adipose-derived stem cells (ASCs), adipocytes, ad-organoids, and Matrigel, and the therapeutic effect was assessed histologically. Our results showed that ad-organoids derived from MVF contained mature adipocytes and a well-established vessel network, secreted multiple adipokines, promoted adipogenic differentiation of ASCs, and suppressed proliferation and migration of scleroderma fibroblasts. Subcutaneous transplantation of ad-organoids reconstructed the subcutaneous fat layer and stimulated dermal adipocyte regeneration in bleomycin-induced scleroderma skin. It reduced collagen deposition and dermal thickness, attenuating dermal fibrosis. Moreover, ad-organoids suppressed macrophage infiltration and promoted angiogenesis in the skin lesion. In conclusion, 3D culturing of MVFs with stepwise angiogenic and adipogenic induction is an effective strategy for the fabrication of ad-organoids, and the transplantation of prefabricated ad-organoids can improve skin sclerosis by restoring cutaneous fat and attenuating skin fibrosis. These findings offer a promising therapeutic approach for the treatment of localized scleroderma.

Single-cell RNA sequencing identifies inherent abnormalities of adipose-derived stem cells from nonlesional sites of patients with localized scleroderma.

BACKGROUND: Localized scleroderma (LoS) is an autoimmune disorder that primarily affects the skin, and is often treated with autologous fat grafting (AFG). Nevertheless, the retention rate of AFG in patients with LoS is typically low. We hypothesize that the low retention rate may be partially attributed to the inherent abnormalities of adipose-derived stem cells (ASCs) from nonlesional sites of patients with LoS. METHODS: We performed a comparative analysis of the single-cell transcriptome of the SVF from nonlesional sites of patients with LoS and healthy donors, including cellular compositional analysis, differential expression analysis, and high-dimensional weighted gene coexpression network analysis. Experimental validation with fluorescence-activated cell sorting and bleomycin-induced skin fibrosis mice models were conducted. RESULTS: We found a significant reduction in the relative proportion of CD55high interstitial progenitors in ASCs under the condition of LoS. Differential expression analysis revealed inherent abnormalities of ASCs from patients with LoS, including enhanced fibrogenesis, reduced anti-inflammatory properties, and increased oxidative stress. Compared with CD55low ASCs, CD55high ASCs expressed significantly higher levels of secreted protein genes that had functions related to anti-inflammation and tissue regeneration (such as CD55, MFAP5, and METRNL). Meanwhile, CD55high ASCs expressed significantly lower levels of secreted protein genes that promote inflammation, such as chemokine and complement protein genes. Furthermore, we provided in vivo experimental evidence that CD55high ASCs had superior treatment efficacy compared with CD55low ASCs in bleomycin-induced skin fibrosis mice models. CONCLUSIONS: We found that the low retention rate of AFG may be partially ascribed to the reduced pool of interstitial progenitor cells (CD55high) present within the ASC population in patients with LoS. We demonstrated the potential for improving the efficacy of AFG in the treatment of LoS by restoring the pool of interstitial progenitors within ASCs. Our study has significant implications for the field of translational regenerative medicine.

High-frequency ultrasound evaluation of morphea: Retrospective analytical study.

BACKGROUND: To date, there are no accepted outcome measures to monitor morphea, and consensus on specific monitoring criteria for morphea remains elusive. A few studies have assessed the criterion validity of skin ultrasound in morphea. So, in this study, we approach ultrasound findings in morphea lesions. MATERIAL AND METHODS: This was a retrospective-analytical study conducted between December 2021 and May 2023. Patients were clinically evaluated at a dermatology outpatient clinic and then referred for high-frequency ultrasound (HF-US) evaluation and were selected to be included in this study. The lesions were confirmed by histopathology as well. Sonographic evaluations were performed on the lesion site and the symmetrical uninvolved other side. Dermal thickness and dermal echogenicities were recorded. Statistical analysis of group differences was performed by using the 2-tailed Student t-test. A p-value of less than 0.05 was considered statistically significant. RESULTS: Forty-one morphea lesions in the inflammatory phase of 27 patients were included in the study. The mean dermal thickness of morphea lesions was 1107.97 ± 414.3 and the mean dermal thickness of the control side was 1094.65 ± 331.06, The difference between these two variables was not statistically significant. The mean dermal density of lesions was 49.13 ± 18.97 and the mean dermal density of the control side was 52.22 ± 25.33. The difference between these two variables was not statistically significant. CONCLUSION: This study shows that HF-US indicated increasing dermal thickness and reducing the dermal density of the morphea lesions in the inflammatory phase confirmed with the histopathology.

A consensus-based electronic medical record template for pediatric morphea patient visits.

Morphea, also known as localized scleroderma, is an inflammatory sclerosing disorder of uncertain pathogenesis that affects the skin and underlying tissues. In the pediatric population, the disease often runs a chronic course with a high risk for irreversible sequelae; as such, patients often require long-term monitoring. The objective of this study is to develop a multi-center, consensus-based electronic medical record template for pediatric morphea patient visits using a modified Delphi method of iterative surveys. By facilitating consistent data collection and interpretation across medical centers and patient populations, this template may improve patient care for pediatric patients with morphea.

Interferon-Gamma-Inducible Protein-10 (IP-10) and Tumor Necrosis Factor-α (TNF-α) as Serological Predictors of Active Disease Status in Localized Scleroderma.

We investigated the ability of a panel of immune-related cytokines and chemokines to predict the disease activity state in localized scleroderma (LS) subjects followed longitudinally. A total of 194 sera samples were obtained from 45 LS subjects with diverse types of LS (40% linear, 20% mixed, 16% craniofacial, 13% generalized, and 11% circumscribed) in our cohort. Cytokines/chemokines that were significantly elevated at the baseline active disease visit compared to the inactive disease state at follow-up were Interferon-Gamma-Inducible Protein (IP)-10 (p < 0.021) and Tumor Necrosis Factor (TNF)-α (p < 0.033). Mixed effect logit modeling identified IP-10 (Odds Ratio (OR) [95% confidence interval] = 2.1 [1.4, 3.2], p < 0.001), TNF-α (OR = 1.8 [1.1, 3.0], p = 0.016), and Monocyte Chemoattractant Protein (MCP)-1 (OR = 2.0 [1.1, 3.9], p = 0.034) as significant predictors of active disease status. These findings support earlier correlations between IP-10 and TNF-α with disease activity parameters in a cross-sectional Luminex™ serological study and may enhance clinical decision-making when disease activity is challenging to assess by clinical examination alone.

S2k guideline: Diagnosis and therapy of localized scleroderma.

The updated S2k guideline deals with the diagnosis and therapy of localized scleroderma (LoS). LoS represents a spectrum of sclerotic skin diseases in which, depending on the subtype and localisation, structures such as adipose tissue, muscles, joints, and bones may also be affected. Involvement of internal organs or progression to systemic sclerosis does not occur. LoS can be classified into four main forms: limited, generalized, linear, and mixed forms, with some additional subtypes. For cases of limited skin involvement, the guideline primarily recommends therapy with topical corticosteroids. UV therapy can also be recommended. In subtypes with severe skin or musculoskeletal involvement, systemic therapy with methotrexate is recommended. During the active phase of the disease, systemic glucocorticosteroids can be used additionally. In cases of methotrexate and steroid refractory courses, contraindications, or intolerance, mycophenolate mofetil, mycophenolic acid, or abatacept can be considered as second-line systemic therapies. In the case of linear LoS, autologous adipose-derived stem cell transplantation can also be performed for correcting soft tissue defects.

Measuring asymmetry in facial morphea via 3-dimensional stereophotogrammetry.

BACKGROUND: Objectively determining tissue loss in craniofacial morphea is challenging. However, 3-dimensional (3D) stereophotogrammetry is a noninvasive modality that may be a useful adjunct. OBJECTIVE: To prospectively evaluate 3D stereophotogrammetry in the assessment of craniofacial linear morphea. METHODS: Participants underwent clinical, quality-of-life, and 3D-stereophotogrammetry assessments. Traditional photographs and 3D-stereophotogrammetry images were rated as mild, moderate, or severe by 2 experts and 2 nonexperts. In addition, interrater and intrarater reliability (on delayed rescoring) were calculated. RESULTS: Of 23 patients with craniofacial morphea, 3D stereophotogrammetry detected pathologic asymmetry in 14 (20.6%) patients. Providers rated patients as more severely affected when using 3D stereophotogrammetry versus when using traditional photographs (19% severe on 3D stereophotogrammetry vs 0% severe on traditional photographs, P = .004). Qualitative ratings of both traditional and 3D images showed high inter- and intrarater reliability between experts and nonexperts alike. Physicians' Global Assessment of Damage scores correlated with mouth asymmetry (P = .0021), cheek asymmetry (P = .04), and 3D-stereophotogrammetry ratings (median, mild: 27.5 vs moderate: 46.5 vs severe: 64, P = .0152). Lower face asymmetry correlated with worse quality-of-life scores (P = .013). LIMITATIONS: Small sample size and cross-sectional design. CONCLUSION: 3D stereophotogrammetry can reliably detect and quantify asymmetry in craniofacial morphea with greater sensitivity than that observed with traditional assessment alone. 3D stereophotogrammetry may be a useful adjunct to clinical examination.

Role of imaging in morphea assessment: A review of the literature.

BACKGROUND: Localized scleroderma, known as morphea, is a connective tissue disorder characterized by inflammation and fibrosis of the skin and the soft tissue. There exist no universally accepted validated outcome measures in order to monitor the disease activity. Besides clinical scores to evaluate outcome measures, imaging modalities are increasingly utilized in assessing patients with morphea, such as high-frequency ultrasonography (US), shear-wave elastography (SWE), and magnetic resonance imaging (MRI). However, the accuracy of these imaging modalities in monitoring morphea activity is not yet clear. AIMS: To review the literature regarding the role of imaging modalities in assessing patients with morphea. MATERIALS & METHODS: In this study, we searched the PubMed/Medline database for articles published from inception until February 2023. RESULTS: A total number of 23 original articles in three categories of US, elastography, and MRI were included. DISCUSSION: Regarding US, criteria, including increased dermal thickness, increased echogenicity of the subcutaneous tissue, and decreased dermal echogenicity, were indicators of active morphea lesions when using high frequencies probe (18-20 MHz) color Doppler sonography. Moreover, studies evaluating SWE, a novel method to quantitatively assess tissue stiffness, demonstrated increased dermal stiffness in active lesions. CONCLUSION: Studies showed that MRI can help to determine the depth of disease, particularly as a first-line and follow-up diagnostic tool, especially in generalized and deep morphea. In addition, brain MRI may be useful for patients with localized craniofacial scleroderma experiencing new or worsening neurological symptoms.

Presenting characteristics and progression of pediatric-onset morphea: Interim analysis of a prospective registry.

Morphea is a rare fibrosing disorder with a highly variable disease course, which can complicate management. Here, we present a prospective cohort study describing the current treatments used in the management of pediatric-onset morphea and assessing responses to systemic and topical therapies. Most patients demonstrated inactive disease by 1 year, regardless of treatment, though recurrences were common in our cohort overall (39%). Our results support the need for continuous monitoring of all children with morphea following the completion of treatment, including topical treatment, due to high rates of disease relapse.

The co-occurrence of segmental vitiligo and linear morphea in a pediatric patient and a review of the literature.

Linear morphea and segmental vitiligo are both autoimmune diseases that are observed in the pediatric population, with rare reports of their co-existence. We describe a case of linear morphea and segmental vitiligo with an overlapping distribution in a pediatric patient and review the literature. Including our own case, we summarize 10 cases of co-occurring segmental vitiligo and morphea in pediatric patients; most of these lesions follow a blaschkolinear distribution, and none of the patients had autoimmune thyroid disease. Although uncommon, the coexistence of segmental vitiligo and linear morphea within lines of Blaschko can occur, and this case suggests that linear morphea and segmental vitiligo may be disorders related to genetic mosaicism.

Morphea after initiation of dupilumab in two pediatric atopic dermatitis patients.

Morphea is a rare multifactorial autoimmune disorder characterized by a complex and dynamic interplay between Th1 and Th2 signaling. Active clinical trials are currently investigating the safety and efficacy of dupilumab for the treatment of primary morphea. Here, we present two cases of morphea that developed in pediatric atopic dermatitis patients treated with dupilumab. These findings may support a causal relationship between IL-4 receptor blockade and the development of the early inflammatory phase of morphea.

Color Doppler Ultrasound Assessment of Subclinical Activity With Scoring of Morphea.

BACKGROUND: Detection of activity in morphea is paramount for adequately managing the disease. Subclinical ultrasound involvement on inactive lesions or healthy skin areas adjacent to morphea has not been described to date. OBJECTIVES: The study aimed to detect morphea's subclinical activity by Color Doppler ultrasound not identified with the clinical scorings. MATERIALS & METHODS: This cross-sectional retrospective study was done from January 2014 to July 2019 in patients with a clinicopathological diagnosis of morphea. The modified Localized Scleroderma Skin Severity Index (mLoSSI) and The Ultrasound Morphea Activity Score (US-MAS) were used to correlate clinical and subclinical activity. RESULTS: A total of 36 patients met the inclusion criteria. 54% of cases presented subclinical activity in areas adjacent to the clinically active lesion, 23% in nonadjacent regions, and 23% demonstrated activity at a clinically inactive lesion site.100% of patients with morphea "en coup de sabre" involving the frontal region of the face concomitantly presented both subclinical activities of morphea on the frontal facial region and the scalp following the same axis.A positive relationship was observed between the degree of clinical activity measured by mLoSSI and US-MAS scoring.The main limitations of our study were the low number of patients and the inability to detect alterations < 0.1 mm. CONCLUSIONS: Subclinical activity is frequent in morphea, can extend beyond the lesional areas, including apparently noninvolved adjacent and distant corporal regions, and can be detected by color Doppler ultrasound.

Fat Grafting Reduces Skin Hyperpigmentation of Localized Scleroderma Patients: A Prospective Self-controlled Study.

BACKGROUND: Localized scleroderma (LS) is characterized by skin fibrosis, hyperpigmentation and soft tissue atrophy. Fat grafting has been widely used to correct LS deformity. OBJECTIVE: To investigate the effect of fat grafting on the skin pigmentation of LS lesions. METHODS: A prospective self-controlled study was conducted. Skin melanin and erythema indexes were measured by Mexameter® MX18 before and 3 months after surgery. Differences between lesions and contralateral normal sites were compared to evaluate changes induced by fat grafting. Localized Scleroderma Cutaneous Assessment Tool and PUMC Localized Scleroderma Facial Aesthetic Index were used for clinical evaluation. RESULTS: Fourteen frontal linear LS patients participated in the study. Before surgery, the melanin index of the lesions was significantly higher than the contralateral sites (p = 0.023), while the erythema indexes were not significantly different (p = 0.426). Three months post-operation, the melanin index of the lesions significantly decreased (p = 0.008). There was no significant change in the erythema index of the lesions before and after fat grafting (p = 0.322). The LoSCAT and PUMC LSFAI scores demonstrated improved disease condition and facial esthetics after surgery. CONCLUSION: Fat grafting could alleviate skin hyperpigmentation and skin damage of LS lesions while having little effect on skin erythema and disease activity. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Synthetic Nucleic Acid Antigens in Localized Scleroderma.

We investigated the impact of synthetic nucleic acid antigens on the autoantibody profiles in patients with localized scleroderma, an autoimmune skin disease. Anti-DNA antibodies, including double-stranded DNA (dsDNA) and single-stranded DNA (ssDNA), are common among autoimmune diseases, such as systemic lupus erythematosus and localized scleroderma. Based on recent studies, we hypothesized that the sequence of nucleic acid antigens has an impact on the autoimmune reactions in localized scleroderma. To test our hypothesis, we synthesized a panel of DNA and RNA antigens and used them for autoantibody profiling of 70 children with localized scleroderma compared with the healthy controls and patients with pediatric systemic lupus erythematosus (as a disease control). Among the tested antigens, dsD4, which contains the sequence of the human oncogene BRAF, showed a particularly strong presence in localized scleroderma but not systemic lupus erythematosus. Disease activity in patients was significantly associated with dsD4 autoantibody levels. We confirmed this result in vivo by using a bleomycin-induced mouse model of localized scleroderma. When administered intraperitoneally, dsD4 promoted an active polyclonal response in the mouse model. Our study highlights sequence specificity for nucleic acid antigens in localized scleroderma that could potentially lead to developing novel early-stage diagnostic tools.

Single-Cell Transcriptome Analysis Identifies Subclusters with Inflammatory Fibroblast Responses in Localized Scleroderma.

Localized scleroderma (LS) is an autoimmune disease with both inflammatory and fibrotic components causing an abnormal deposition of collagen in the skin and underlying tissue, often leading to disfigurement and disability. Much of its pathophysiology is extrapolated from systemic sclerosis (SSc) since the histopathology findings in the skin are nearly identical. However, LS is critically understudied. Single-cell RNA sequencing (scRNA seq) technology provides a novel way to obtain detailed information at the individual cellular level, overcoming this barrier. Here, we analyzed the affected skin of 14 patients with LS (pediatric and adult) and 14 healthy controls. Fibroblast populations were the focus, since they are the main drivers of fibrosis in SSc. We identified 12 fibroblast subclusters in LS, which overall had an inflammatory gene expression (IFN and HLA-associated genes). A myofibroblast-like cluster (SFRP4/PRSS23) was more prevalent in LS subjects and shared many upregulated genes expressed in SSc-associated myofibroblasts, though it also had strong expression of CXCL9/10/11, known CXCR3 ligands. A CXCL2/IRF1 cluster identified was unique to LS, with a robust inflammatory gene signature, including IL-6, and according to cell communication analysis are influenced by macrophages. In summary, potential disease-propagating fibroblasts and associated gene signatures were identified in LS skin via scRNA seq.

Clinical and laboratory characterization of patients with localized scleroderma and response to UVA-1 phototherapy: In vivo and in vitro skin models.

BACKGROUND/PURPOSE: Localized scleroderma (LS) is a rare disease leading to progressive hardening and induration of the skin and subcutaneous tissues. LS is responsive to UVA-1 phototherapy, though its exact mechanism of action dermal fibrosis is yet to be fully elucidated. We aimed to investigate the molecular changes induced by UVA-1 rays in human primary fibroblasts cultures. METHODS: A total of 16 LS patients were treated with medium-dose UVA-1 phototherapy. At baseline, during and after therapy, Localized Scleroderma Assessment Tool, Dermatology Life Quality Index and lesions' staging and mapping were performed along with high-frequency ultrasound (HFUS) examination for dermal thickness assessment. Gene expression analysis for 23 mRNA transcripts, in vitro UVA-1 irradiation and viability tests were realized on lesional fibroblasts' primary cultures, before and 3 months after therapy. RESULTS: The dermal thickness, the LoSCAT and the DLQI progressively decreased starting from the last phototherapy session up to the 6 and 9 month follow-ups (-57% and -60%, respectively). Molecular gene analysis (rt-PCR) revealed that UVA-1 phototherapy exerts multiple effects: the activation of specific anti-fibrotic pathways (e.g., overexpression of CTHRC1 and metalloproteases 1, 2, 7, 8, 9, 12, suppression of TIMP-1), the downregulation of peculiar pro-fibrotic pathways (e.g., downregulation of TGF-ß, TGF-ßrII, Grb2, SMAD 2/3, TNRSF12A, CTGF) through a significant overexpression of IL-1ß; the stabilization of collagen synthesis acting on genes COL1A1, COL3A1, COL8A1, COL10A1, COL12A1. CONCLUSION: UVA-1 phototherapy adds significant benefits in local tissue remodeling, rebalancing the alteration between pro-fibrotic and anti-fibrotic pathways; these changes can be well monitored by HFUS.

Frontal Linear Scleroderma (en coup de sabre): A Case Report.

En coup de sabre is an unusual variant of localized scleroderma characterized by its distinct location involving the frontoparietal region of the forehead and scalp. The authors describe a rare case of en coup de sabre in a 3-year-old boy whose disease onset was at 12 months of age. This article presents the clinical manifestations of continuous changes in the lesion photographed over time. The clinical presentation, laboratory results, and radiological findings together with a brief discussion of the management of the disease are discussed.

Effectiveness of PUVA vs. UVA1 phototherapy in the treatment of morphea patients.

Introduction: Morphea (localized scleroderma) is an inflammatory connective tissue disease, characterized by immune system dysfunction, vasculopathy and skin fibrosing. Phototherapy has been found to be effective in treating localized scleroderma. Psoralen + ultraviolet A (PUVA) and ultraviolet A1 (UVA1) phototherapy significantly enriched therapeutic possibilities. Aim: To compare the clinical effect of PUVA photochemotherapy and UVA1 phototherapy and to evaluate the treatment response rates. Material and methods: It was a retrospective one-centre research and observational study of all morphea patients treated with PUVA and UVA phototherapy. We reviewed phototherapy notes along with electronic and paper case records for all patients with morphea treated with PUVA and UVA1 phototherapy from January 2010 to December 2019. Results: The study shows that patients in both groups experienced improvement based on clinical measures, resulting in a reduction in the clinical score in all groups. There is positive short- and long-term efficacy of UVA1 and PUVA phototherapy in patients with morphea. There were no statistical differences between the treatment response rates. Limitations: We had a relatively small study sample and it was a retrospective, observational study. Conclusions: Our data suggest that ultraviolet PUVA and UVA1 should be considered for the treatment of morphea with disseminated lesions or not responding to topical treatment. UVA1 is free of side effects linked to oral psoralens such as nausea, vomiting, photokeratosis, but we showed that there was no statistical advantage in the effectiveness of both. UVA1 phototherapy is, however, a less accessible form of treatment, available in the centres of higher quality.

Concentrations of metalloproteinase-1 in patients with morphea treated with phototherapy: a preliminary study.

Introduction: Morphea (localized scleroderma) is a rare, chronic, inflammatory connective tissue disease, characterized by immune system dysfunction, vasculopathy and skin fibrosis. One of the most effective treatments is phototherapy. Phototherapy has been found to be effective in treating localized scleroderma by inducing the expression of metalloproteinase-1. Aim: To compare the concentrations of metalloproteinase (MMP-1) before psoralen and ultraviolet A (PUVA) and ultraviolet A1 (UVA1) treatments in the serum of patients with morphea. Material and methods: The observational study was conducted in one research centre and included patients with generalised morphea who were treated with PUVA and UVA1 phototherapies. The mean age of all morphea patients included in the study was 55.7 years. The levels of MMP-1 were examined by ELISA (The Biorbyt Human MMP-1 ELISA - Enzyme-Linked Immunosorbent Assay). Results: The study showed that patients treated with PUVA and UVA1 had an improvement based on clinical measures, resulting in a reduction of clinical score. However, we did not observe statistically significant differences in MMP-1 concentrations before and after treatment. Limitations: The study sample was relatively small. Further studies on a larger group of patients would be beneficial. Conclusions: Our data suggest that there is a possible correlation between MMP-1 concentrations and phototherapy. MMP-1 levels were found to be increased following phototherapy treatment, which may suggest a correlation with better response to treatment in patients with morphea. However, further research is needed.

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.