The molecular pathogenesis of morphoea: from genetics to future treatment targets

Morphoea presenting histopathologically as mycosis fungoides: an illustrative series of four cases

AIMS

There have been exceptional reports of morphoea presenting with epidermal changes overlapping histopathologically with cutaneous T cell lymphoma of the mycosis fungoides type (MF). This phenomenon gives rise to an ambiguous clinicopathological scenario in which distinguishing these conditions may be challenging. The aim of this study is to characterise the clinical, histopathological and molecular findings of this phenomenon through a case series.

METHODS AND RESULTS

Four patients with classical clinical presentation of morphoea but unusual histopathology displaying typical findings of morphoea, together with intra-epidermal CD8 positive lymphocytes indistinguishable from MF, were identified. The clinical phenotypes of morphoea were varied, and they all presented early in the active phase of the disease. They all exhibited intra-epidermal lymphocytes with tagging and cytological atypia. Pautrier-like microabscesses were also seen. Using molecular analysis, two cases showed clonal TCR gene rearrangement. Follow-up of all cases has been consistent with classical morphoea.

CONCLUSION

Early morphoea can seldom present with atypical clonal intra-epidermal lymphocytes indistinguishable from MF. The fact that these changes can occur in several different clinical subtypes of morphoea raises the possibility that this could be a pattern of inflammation in early disease more common than currently appreciated.

Unravelling morphoea aetiopathogenesis by next-generation sequencing of paired skin biopsies

BACKGROUND

Morphoea can have a significant disease burden. Aetiopathogenesis remains poorly understood, with very limited existing genetic studies. Linear morphoea (LM) may follow Blascho's lines of epidermal development, providing potential pathogenic clues.

OBJECTIVE

The first objective of this study was to identify the presence of primary somatic epidermal mosaicism in LM. The second objective was tTo explore differential gene expression in morphoea epidermis and dermis to identify potential pathogenic molecular pathways and tissue layer cross-talk.

METHODOLOGY

Skin biopsies from paired affected and contralateral unaffected skin were taken from 16 patients with LM. Epidermis and dermis were isolated using a 2-step chemical-physical separation protocol. Whole Genome Sequencing (WGS; n = 4 epidermal) and RNA-seq (n = 5-epidermal, n = 5-dermal) with gene expression analysis via GSEA-MSigDBv6.3 and PANTHER-v14.1 pathway analyses, were performed. RTqPCR and immunohistochemistry were used to replicate key results.

RESULTS

Sixteen participants (93.8% female, mean age 27.7 yrs disease-onset) were included. Epidermal WGS identified no single affected gene or SNV. However, many potential disease-relevant pathogenic variants were present, including ADAMTSL1 and ADAMTS16. A highly proliferative, inflammatory and profibrotic epidermis was seen, with significantly-overexpressed TNFα-via-NFkB, TGFβ, IL6/JAKSTAT and IFN-signaling, apoptosis, p53 and KRAS-responses. Upregulated IFI27 and downregulated LAMA4 potentially represent initiating epidermal 'damage' signals and enhanced epidermal-dermal communication. Morphoea dermis exhibited significant profibrotic, B-cell and IFN-signatures, and upregulated morphogenic patterning pathways such as Wnt.

CONCLUSION

This study supports the absence of somatic epidermal mosaicism in LM, and identifies potential disease-driving epidermal mechanisms, epidermal-dermal interactions and disease-specific dermal differential-gene-expression in morphoea. We propose a potential molecular narrative for morphoea aetiopathogenesis which could help guide future targeted studies and therapies.

Novel role of long non-coding RNAs in autoimmune cutaneous disease

Systemic autoimmune rheumatic diseases (SARDs) are a heterogeneous group of chronic multisystem inflammatory disorders that are thought to have a complex pathophysiology, which is not yet fully understood. Recently, the role of non-coding RNAs, including long non-coding RNA (lncRNA), has been of particular interest in the pathogenesis of SARDs. We aimed to summarize the potential roles of lncRNA in SARDs affecting the skin including, systemic sclerosis (SSc), dermatomyositis (DM) and cutaneous lupus erythematosus (CLE). We conducted a narrative review summarizing original articles published until July 19, 2021, regarding lncRNA associated with SSc, DM, and CLE. Several lncRNAs were hypothesized to play an important role in disease pathogenesis of SSc, DM and CLE. In SSc, Negative Regulator of IFN Response (NRIR) was thought to modulate Interferon (IFN) response in monocytes, anti-sense gene to X-inactivation specific transcript (TSIX) to regulate increased collagen stability, HOX transcript antisense RNA (HOTAIR) to increase numbers of myofibroblasts, OTUD6B-Anti-Sense RNA 1 to decrease fibroblast apoptosis, ncRNA00201 to regulate pathways in SSc pathogenesis and carcinogenesis, H19X potentiating TGF-β-driven extracellular matrix production, and finally PSMB8-AS1 potentiates IFN response. In DM, linc-DGCR6-1 expression was hypothesized to target the USP18 protein, a type 1 IFN-inducible protein that is considered a key regulator of IFN signaling. Additionally, AL136018.1 is suggested to regulate the expression Cathepsin G, which increases the permeability of vascular endothelial cells and the chemotaxis of inflammatory cells in peripheral blood and muscle tissue in DM. Lastly, lnc-MIPOL1-6 and lnc-DDX47-3 in discoid CLE were thought to be associated with the expression of chemokines, which are significant in Th1 mediated disease. In this review, we summarize the key lncRNAs that may drive pathogenesis of these connective tissue diseases and could potentially serve as therapeutic targets in the future.

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.

Serum Levels of Selected IL-1 Family Cytokines in Patients with Morphea

Morphea/localized scleroderma (LoS) represents an inflammatory-sclerotic skin disease, the pathogenesis of which is not fully understood. Given the important role of IL-1 family cytokines in the development and therapy of inflammatory diseases, including systemic sclerosis, we analyzed the clinical significance of serum levels of selected IL-1 family cytokines (IL-1α, IL-1β, IL-18, IL-33, IL-37 and IL-38) in LoS patients (n = 30) using the standardized disease assessment tools and comparison to healthy controls (n = 28). We also compared the pre- and post-treatment concentrations, i.e., before and after systemic (glucocorticosteroids and/or methotrexate) and/or topical (topical glucocorticosteroids and/or calcineurin inhibitors). Our findings did not reveal significant differences in baseline IL-1α, IL-1β, IL-18, IL-33, IL-37 and IL-38 levels between LoS group and HCs; however, after treatment, there were marked changes in concentrations of IL-1α and IL-33 within LoS group as well as in comparison to HCs. We also found significant negative correlations between PGA-A and IL-1α concentration as well as between mLoSSI and IL-1α after treatment. Furthermore, we showed an inverse correlation of baseline IL-1β levels with mLoSSI scores of borderline significance. We believe that IL-1α and IL-33, as well as Il-1β, may be potential mediators and targets of interest in LoS.

Fractional Ablative Carbon Dioxide Lasers for the Treatment of Morphea: A Case Series and Literature Review

Morphea is an inflammatory, immune-mediated disease of unknown aetiology. It is characterised by excessive collagen deposition, which leads to the hardening of the dermis and subcutaneous tissues. The disease is associated with cosmetic and functional impairment, which can affect the patients’ quality of life. Fractional ablative lasers (FALs) are currently used for the treatment of many skin diseases that are connected to tissue fibrosis due to the low risk of side effects and their great effectiveness. This study aimed to improve the aesthetic defects that are caused by morphea lesions and assess the efficacy and safety of FAL use in this indication. We also reviewed the literature on the subject. We present four women with biopsy-proven morphea, manifesting as hyperpigmented plaques and patches. One of the patients additionally had morphea-related knee joint contracture. Four fractional CO2 laser sessions, separated by one-month intervals, were performed and produced significant improvements in dyspigmentation and induration. An improved elasticity and a decrease in dermal thickness were also obtained, as proven by measurements using DermaLab Combo. No severe adverse effects occurred. Based on these cases presented by the authors, fractional CO2 lasers appear to be an effective, well-tolerated, and safe therapeutic option for patients suffering from morphea.

Linear scleroderma in a child with central nervous system involvement: clinical and radiological features

Linear scleroderma is the most common type of localized scleroderma in children. Lesions rarely involve areas other than the skin, and nervous system involvement is even rare. We reported a case of a 6-year-old girl who was admitted to the hospital with recurrent seizures for 4 weeks. Before that, she had left frontal plaques for more than 1 year. Radiological imaging of the brain showed multiple abnormal lesions and skin biopsy of the plaques indicated scleroderma. After drug therapy, the girl had no recurrence of epilepsy, and no obvious abnormalities were found in the reexamination of neuroimaging. We performed further radiological examination on this patient and reviewed the literatures for this rare case.

Juvenile Localized Scleroderma: Updates and Differences from Adult-Onset Disease

Children and adolescents with localized scleroderma (LS) are at high risk for extracutaneous-related functional impairment including hemiatrophy, arthropathy, seizures, and vision impairment. Compared with adult-onset LS, pediatric disease has a higher likelihood for poor outcome, with extracutaneous involvement twice as prevalent in linear scleroderma, disease relapses more common, and disease duration more than double. Consensus among pediatric rheumatologists on treating patients at risk for significant morbidity with systemic immunosuppressants has led to major improvements in outcome. This review discusses recent progress in assessment and treatment strategies and in our understanding of key disease pathways.

Morphea as Part of the Dermatological Manifestation of Celiac Disease: Case Presentation and Review of the Literature

Celiac disease is an immune-mediated disease, affecting multiple systems and organs including several dermatological conditions. Morphea, or localized scleroderma, is also an immune-mediated condition, in which an association with celiac disease has not thus far been recognized. We present an interesting case report of a 10-year-old child with a recent diagnosis of celiac disease presenting with morphea. Following treatment and adherence to a gluten-free diet, the morphea rapidly resolved. We suggest a possible relationship between the two entities and give a brief review of the relevant literature. We suggest that morphea might be one of the many dermatological manifestations of celiac disease, with possible implications for the need to screen patients with morphea for celiac disease.

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.

Morphea: progress to date and the road ahead

Morphea is a rare autoimmune condition causing inflammation and sclerosis of the skin and underlying soft tissue. It is characterized by periods of activity (inflammation admixed with fibrosis), ultimately resulting in permanent damage (pigment change and tissue loss). Damage resulting from unchecked activity can lead to devastating, permanent cosmetic and functional sequelae including hair loss; cutaneous, soft tissue and bony atrophy; joint contractures; and growth restriction of the affected body site in children. This makes the early identification of activity and initiation of appropriate treatment crucial to limiting damage in morphea. To this end, recent investigative work has focused on validation of clinical, biomarker, imaging, and histologic outcomes aimed at accurately quantifying activity and damage. Despite promising results, further work is needed to better validate these measures before they can be used in the clinic and research settings. Although there has been recent approval of less toxic, targeted therapies for many inflammatory skin conditions, none have been systematically investigated in morphea. The mainstays of treatment for active morphea are corticosteroids and methotrexate. These are often limited by substantial toxicity. The paucity of new treatments for morphea is the result of a lack of studies examining its pathogenesis, with many reviews extrapolating from research in systemic sclerosis. Recent studies have demonstrated the role of dysregulated immune and fibrotic pathways in the pathogenesis of morphea, particularly interferon (IFN) gamma related pathways. Active morphea lesions have been found to display an inflammatory morphea signature with CXCR3 receptor ligands, as well as a distinct fibrotic signature reflecting fibroblast activation and collagen production. CXCL9 and 10 have been associated with increased measures of disease activity. While immune dysfunction is thought to play the primary role in morphea pathogenesis, there are other factors that may also contribute, including genetic predisposition, environmental factors, and vascular dysregulation. There remains an essential need for further research to elucidate the pathogenesis of morphea and the mode of action of dysregulated upstream and downstream immune and fibrotic pathways. These studies will allow for the discovery of novel biomarkers and targets for therapeutic development.

Single-cell transcriptome conservation in a comparative analysis of fresh and cryopreserved human skin tissue: pilot in localized scleroderma

BACKGROUND

The purpose of this study was to assess variability in cell composition and cell-specific gene expression in the skin of patients with localized scleroderma (LS) utilizing CryoStor® CS10 in comparison to RPMI to produce adequate preservation of tissue samples and cell types of interest for use in large-scale multi-institutional collaborations studying localized scleroderma and other skin disorders.

METHODS

We performed single-cell RNA sequencing on paired skin biopsy specimens from 3 patients with LS. Each patient with one sample cryopreserved in CryoStor® CS10 and one fresh in RPMI media using 10× Genomics sequencing.

RESULTS

Levels of cell viability and yield were comparable between CryoStor® CS10 (frozen) and RPMI (fresh) preserved cells. Furthermore, gene expression between preservation methods was collectively significantly correlated and conserved across all 18 identified cell cluster populations.

CONCLUSION

Comparable cell population and transcript expression yields between CryoStor® CS10 and RPMI preserved cells support the utilization of cryopreserved skin tissue in single-cell analysis. This suggests that employing standardized cryopreservation protocols for the skin tissue will help facilitate multi-site collaborations looking to identify mechanisms of disease in disorders characterized by cutaneous pathology.

Paediatric morphoea: a holistic review. Part 1: epidemiology, aetiopathogenesis and clinical classification

Morphoea, also known as localized scleroderma, is a debilitating fibrosing disorder of uncertain aetiology, affecting the skin and subcutaneous tissues. Paediatric-onset disease is not uncommon and is associated with frequent relapses. The disease has complex pathogenetic mechanisms and multiple clinical subtypes, and affects children of all ages. Recent research has focused on elucidating the disease pathophysiology and identifying measures of disease activity. We performed a literature search on PubMed, MEDLINE and Google Scholar, using keywords such as 'pediatric morphea', 'juvenile localised scleroderma' and 'juvenile systemic sclerosis'. Relevant studies, including randomized trials, reviews of standard current guidelines and original research articles, were selected, and results were analysed before being summarized. In the first of this two-part review, we provide a bird's-eye view of the current literature concerning the epidemiology, aetiopathogenesis and clinical classification of paediatric morphoea; in Part 2, we review the diagnosis, markers of disease activity, management and natural history.

Histopathologic Spectrum of Morphea

ABSTRACT

Morphea is an autoimmune skin disease with protean clinical manifestations. Histologic features are similarly variable, and skin biopsies may be nondiagnostic. A single-institution retrospective cohort study was conducted. Morphea patients who had a biopsy in 2005-2015 were included, and a histopathological review was conducted by 2 pathologists. There were 51 biopsy specimens from 40 subjects. The most common histologic features were dermal sclerosis (90%), dermal thickening (78%), collagen homogenization (86%), a superficial and deep infiltrate (76%), a moderate-abundant inflammatory infiltrate (73%), and periadnexal fat loss/decreased skin appendages (71%). Twenty-four specimens were not diagnostic of morphea. In these specimens, the main clues to diagnosis included the presence of dermal sclerosis (79%), subtle collagen homogenization (75%), dermal thickening (58%), moderate-to-abundant plasma cells (50%), and perineural inflammation (50%). There were no statistically significant differences between active and inactive lesions, nor untreated and treated lesions. The histopathologic features of morphea are variable and a high proportion of biopsies are not diagnostic. Clinicians and pathologists should have a high degree of suspicion to correctly make the diagnosis of morphea.

Overview of Juvenile localized scleroderma and its management

BACKGROUND

Juvenile localized scleroderma (JLS) is a rare pediatric disease characterized by inflammation and skin thickening. JLS is associated with deep tissue and extracutaneous involvement that often results in functional impairment and growth disturbances. This article provides an overview of the disease with a focus on active features and treatment.

DATA SOURCES

We searched databases including PubMed, Elsevier and MedLine and Wanfang, reviewing publications from 2013 to 2019. Selected earlier publications were also reviewed.

RESULTS

Linear scleroderma is the most common JLS subtype. Several lines of evidence suggest that JLS is an autoimmune disease. Extracutaneous involvement is common and can present before the onset of skin disease. Multiple skin features are associated with disease activity, and activity can also manifest as arthritis, myositis, uveitis, seizures, and growth impairment. Systemic immunosuppressive treatment, commonly methotrexate with or without glucocorticoids, greatly improves outcome and is recommended for treating JLS patients with active disease and moderate or higher severity. Long term monitoring is needed because of the disease's chronicity and the high frequency of relapses off of treatment.

CONCLUSIONS

JLS is associated with a risk for disabling and disfiguring morbidity for the growing child. Identifying active disease is important for guiding treatment, but often difficult because of the paucity of markers and lack of a universal skin activity feature. More studies of JLS pathophysiology are needed to allow the identification of biomarkers and therapeutic targets. Comparative effectiveness treatment studies are also needed to work towards optimizing care and outcome.

Update on the Systemic Treatment of Pediatric Localized Scleroderma

Juvenile localized scleroderma (jLS) is an orphan disease that can lead to cosmetic disfiguration and orthopedic problems. Two recent publications review the current recommendations regarding diagnosis, assessment, follow up and treatment of pediatric localized scleroderma cases, both of which suggest the Localized Scleroderma Cutaneous Assessment Tool as an important instrument to assess activity and damage. This review focuses on the systemic treatment of jLS. Systemic treatment includes synthetic and biologic disease-modifying antirheumatic drugs. Systemic therapy is indicated if the lesion crosses any joint, or leads to potential cosmetic disfiguration or orthopedic problems. The only controlled trial of systemic treatment has shown the efficacy of methotrexate, which is the first choice of treatment. It appears superior to phototherapy according to a recently published meta-analysis. In case of methotrexate intolerance, mycophenolate mofetil is an option. In case of methotrexate nonresponse, addition of mycophenolate mofetil, tocilizumab or abatacept seems to be effective. Future treatment options derived and extrapolated from adult trials regarding treatment of skin involvement of systemic scleroderma or fibrosis are promising, as the final pathway in the skin seems to be similar in both diseases.

MicroRNA in localized scleroderma: a review of literature

Localized scleroderma (LoSc) is rare connective tissue disease that manifests with inflammation and fibrosis of the skin. Depending on the LoSc subtype, adjacent structures such as subcutaneous tissue, fascia, muscles, bones may be affected. The hallmark of fibrosis is tissue remodelling with excess deposition of extracellular matrix proteins (ECM), principally collagens. MicroRNAs (miRNAs) are small, noncoding RNA molecules that consist of 19-24 nucleotides and act as negative regulators of gene expression at the posttranscriptional level. Based on the current articles, approximately 40 microRNAs have been linked to fibrosis in different organs and diseases. The majority of these molecules promote or inhibit fibrosis by targeting connective tissue growth factor (CTGF), extracellular matrix proteins, TGF-β pathway and MAPK (mitogen-activated protein kinase) pathway. Further, particular microRNAs regulate fibrogenesis by altering epithelial-to-mesenchymal transition (EMT) or activating proliferation of myofibroblasts. MiRNAs are relatively stable, detectable in tissues and body fluids (serum, plasma) which suggest that they may serve as beneficial biomarkers to monitor the course of the disease and response to treatment. Herein, we report the present state of knowledge on microRNA expression in localized scleroderma.

Diagnosis and management of linear scleroderma in children

PURPOSE OF REVIEW

Linear scleroderma is the most common subtype of localized scleroderma (LoS) in children. It can be associated with extracutaneous manifestations and long-term sequelae. Thus, appropriate diagnosis and management are key to improve the prognosis. In this review, we summarize the most relevant recent publications for the diagnosis, evaluation of disease activity and adequate management of patients with linear scleroderma.

RECENT FINDINGS

There are specific clinical features that indicate activity in LoS; dermoscopy and Wood's lamp may be useful. Summarizing, scoring methods seem to provide the most adequate assessment of LoS; but several biomarkers that correlate with activity have been studied: E-selectin and IL-2 receptor, CD34+ dermal dendritic cells and Th/Th1 immunophenotype with decreased T helper (Th2), T regulatory (Tregs), B and natural killer (NK) cells. Recent studies propose hydroxychloroquine monotherapy and tocilizumab as potential therapeutic options.

SUMMARY

Clinical evaluation, both physical exam and history, is the most important aspect in diagnosing and assessing activity of linear scleroderma. Clinical scoring methods may be most useful for evaluation of activity; eventually, other biomarkers could be relevant in clinical practice. For most patients with linear scleroderma, the first choice of treatment is methotrexate, but physical therapy, plastic surgery and/or orthopedic management are key to improve residual limitations and quality of life. VIDEO ABSTRACT: http://links.lww.com/MOP/A35.

Autoantibodies in Morphea: An Update

Skin autoimmune conditions belong to a larger group of connective tissue diseases and primarily affect the skin, but might also involve underlying tissues, such as fat tissue, muscle, and bone. Autoimmune antibodies (autoantibodies) play a role in autoimmune skin diseases, such as localized scleroderma also termed morphea, and systemic scleroderma, also called systemic sclerosis (SSc). The detailed studies on the biological role of autoantibodies in autoimmune skin diseases are limited. This results in a few available tools for effective diagnosis and management of autoimmune skin diseases. This review aims to provide an update on the detection and most recent research on autoantibodies in morphea. Several recent studies have indicated the association of autoantibody profiles with disease subtypes, damage extent, and relapse potential, opening up exciting new possibilities for personalized disease management. We discuss the role of existing autoantibody tests in morphea management and the most recent studies on morphea pathogenesis. We also provide an update on novel autoantibody biomarkers for the diagnosis and study of morphea.

Morphea - selected local treatment methods and their effectiveness

Localised scleroderma is an uncommon connective tissue disease of multifactorial aetiology occurring in the paediatric and adult population. It is relatively difficult to conduct any research on the subject of this disease entity treatment due to the low number of patients suffering from morphea, a tendency of the disease to remit spontaneously, and not yet well recognised aetiology. Hence, there has been developed no causal treatment of well-proven effectiveness, and schedules of symptomatic therapy are not yet clearly determined. The paper depicts most widely used topical treatment methods in morphea therapy, which due to minor risk of systemic adverse effects seem to be a beneficial therapeutic alternative. The main aim of this article was to analyse different topical treatment options used in localised scleroderma therapy and to indicate the most appropriate, safe, and effective one.