Environmental risk factors of systemic sclerosis

Anti-Ro52 positivity is associated with progressive interstitial lung disease in systemic sclerosis-an exploratory study

BACKGROUND

Interstitial lung disease (ILD) is the most common cause of death in patients with systemic sclerosis (SSc). Prognostic biomarkers are needed to identify SSc-ILD patients at risk for progressive pulmonary fibrosis. This study investigates autoantibodies measured in bronchoalveolar lavage (BAL) fluid and in serum in reference to the clinical disease course of SSc-ILD.

METHODS

Fifteen patients with new onset SSc-ILD underwent bronchoscopy. Autoantibody levels were analyzed using addressable laser bead immunoassay from BAL fluid and the serum. In a separate longitudinal cohort of 43 patients with early SSc-ILD, autoantibodies in serum were measured at baseline and pulmonary function tests were performed at least 2 times over the course of at least 2 or more years. Linear mixed effect models were created to investigate the relationship between specific autoantibodies and progression of SSc-ILD. Finally, lung tissue from healthy controls and from subjects with SSc was analyzed for the presence of the Ro52 antigen using immunohistochemistry.

RESULTS

Among SSc-ILD patients who were positive for anti-Ro52 (N = 5), 3 (60%) had enrichment of anti-Ro52 in BAL fluid at a ratio exceeding 50x. In the longitudinal cohort, 10/43 patients (23%) were anti-Ro52 positive and 16/43 (37%) were anti-scl-70 positive. Presence of anti-Scl-70 was associated with a lower vital capacity (VC) at baseline (-12.6% predicted VC [%pVC]; 95%CI: -25.0, -0.29; p = 0.045), but was not significantly associated with loss of lung function over time (-1.07%pVC/year; 95%CI: -2.86, 0.71; p = 0.230). The presence of anti-Ro52 was significantly associated with the loss of lung function over time (-2.41%pVC/year; 95% CI: -4.28, -0.54; p = 0.013). Rate of loss of lung function increased linearly with increasing anti-Ro52 antibody levels (-0.03%pVC per arbitrary units/mL and year; 95%CI: -0.05, -0.02; p < 0.001). Immunohistochemical staining localized the Ro52 antigen to alveolar M2 macrophages in peripheral lung tissue both in subjects with and without SSc.

CONCLUSIONS

This study suggests that antibodies targeting Ro52 are enriched in the lungs of patients with new-onset SSc-ILD, linking Ro52 autoimmunity to the pulmonary pathology of SSc. Clinical and immunohistochemical data corroborates these findings and suggest that anti-Ro52 may serve as a potential biomarker of progressive SSc-ILD.

Pathogenetic rationale for prescribing menopausal hormone therapy for systemic sclerosis

Systemic scleroderma (SS) is characterized by dysregulation of the innate and adaptive immune systems, vasculopathy, and generalized fibrosis. As with most autoimmune diseases, women predominate among patients, who get sick 3–14 times more often than men. It is assumed that gender differences and modulation of sex hormones are essential in the pathogenesis of SS. Estrogens are able to influence the immune response, have a vasodilating effect and stimulate the synthesis of collagen in the skin. The development of SS leads to a significant decrease in the quality of life, psychological disorders associated with changes in appearance, as well as the need for lifelong medication with the frequent development of side effects. Age-related estrogen deficiency associated with the onset of menopause is accompanied by a decrease in the quality of life and, in some cases, a change in the clinical manifestations of somatic diseases. This review considers the impact of menopause and menopausal hormone therapy (MHT) on the course and clinical manifestations of systemic scleroderma. It is noted that SS in some cases is accompanied by an early onset of menopause. The use of MHT is not associated with the progression of cutaneous fibrosis, and may also improve the vascular manifestations of SS.

Systemic sclerosis in adults. Part I: Clinical features and pathogenesis

Systemic sclerosis (SSc), also referred to as systemic scleroderma or scleroderma, is a rare, complex immune-mediated connective tissue disease characterized by progressive skin fibrosis and other clinically heterogenous features. The etiopathogenesis of SSc involves vasculopathy and immune system dysregulation occurring on a permissive genetic and epigenetic background, ultimately leading to fibrosis. Recent developments in our understanding of disease-specific autoantibodies and bioinformatic analyses has led to a reconsideration of the purely clinical classification of diffuse and limited cutaneous SSc subgroups. Autoantibody profiles are predictive of skin and internal organ involvement and disease course. Early diagnosis of SSc, with commencement of disease-modifying treatment, has the potential to improve patient outcomes. In SSc, many of the clinical manifestations that present early signs of disease progression and activity are cutaneous, meaning dermatologists can and should play a key role in the diagnosis and management of this significant condition. The first article in this continuing medical education series discusses the epidemiology, clinical characteristics, and pathogenesis of SSc in adults, with an emphasis on skin manifestations, the important role of dermatologists in recognizing these, and their correlation with systemic features and disease course.

Cellular-Based Therapies in Systemic Sclerosis: From Hematopoietic Stem Cell Transplant to Innovative Approaches

Systemic sclerosis (SSc) is a systemic disease characterized by autoimmune responses, vasculopathy and tissue fibrosis. The pathogenic mechanisms involve a wide range of cells and soluble factors. The complexity of interactions leads to heterogeneous clinical features in terms of the extent, severity, and rate of progression of skin fibrosis and internal organ involvement. Available disease-modifying drugs have only modest effects on halting disease progression and may be associated with significant side effects. Therefore, cellular therapies have been developed aiming at the restoration of immunologic self-tolerance in order to provide durable remissions or to foster tissue regeneration. Currently, SSc is recommended as the 'standard indication' for autologous hematopoietic stem cell transplantation by the European Society for Blood and Marrow Transplantation. This review provides an overview on cellular therapies in SSc, from pre-clinical models to clinical applications, opening towards more advanced cellular therapies, such as mesenchymal stem cells, regulatory T cells and potentially CAR-T-cell therapies.

Drugs associated with systemic sclerosis: An updated list of suspected drugs using the WHO pharmacovigilance database

OBJECTIVE

The pathophysiological mechanisms involved in systemic sclerosis (SSc), especially the triggering factor, are poorly understood. The literature supporting the role of drugs in the onset of SSc primarily relies on case reports, short series or previous studies of old drugs. We aimed to update the list of suspected drugs associated with SSc (DASSc).

METHODS

Analyzing the World Health Organization (WHO) pharmacovigilance database (Vigibase®), we collected all individual case safety reports (ICSRs) of drugs putatively associated with SSc reported since 1967 using the Medical Dictionary for Regulatory Activities preferred terms "systemic sclerosis" and "scleroderma". For each drug, a disproportionality analysis was performed by calculating the information component (IC). An identified drug was considered significant if the IC₀₂₅ was >0.

RESULTS

A total of 2800 deduplicated ICSRs of DASSc were identified, accounting for 509 ICSRs and 38 suspected DASSc after exclusion of protopathic and indication biases. Anticancer drugs were the most represented drug class, accounting for 16/38 (42%) of DASSc and 317/509 (62.3%) of ICSRs, which occurred mostly in the first years after the introduction of the drugs. Among these, taxane-based agents, bleomycin, vinblastine, imatinib, dacarbazine, pembrolizumab and pemetrexed were associated with the highest disproportionate reporting. Hormone replacement therapy, romiplostim and eculizumab were associated with a significant signal. DASSc was considered a serious adverse drug reaction in 404 (92%, n = 441) cases with 41 (9%) cases resulting in death.

CONCLUSION

Several new drugs with significant disproportionality signals were identified as potential drugs implicated the development of SSc, particularly anticancer drugs.

Role of Environment in Pediatric Rheumatic Diseases

Studying environmental risk factors for pediatric rheumatic diseases (PRD) is important because the identification of these factors may lead to strategies to prevent disease, and to new insights into pathogenesis and therapeutic targets. Compared with other chronic diseases, there are few environmental epidemiology studies in PRD. Although strong risk factors common to all PRDs have not been identified, some exposures including infection, smoke exposure, and ultraviolet radiation have been associated with several of them. High-technology studies, especially of microbiomics and metabolomics, are increasing and will likely lead to new understandings of the complex interplay between environment, genetics, and disease.

Human Cytomegalovirus and Autoimmune Diseases: Where Are We?

Human cytomegalovirus (HCMV) is a ubiquitous double-stranded DNA virus belonging to the β-subgroup of the herpesvirus family. After the initial infection, the virus establishes latency in poorly differentiated myeloid precursors from where it can reactivate at later times to cause recurrences. In immunocompetent subjects, primary HCMV infection is usually asymptomatic, while in immunocompromised patients, HCMV infection can lead to severe, life-threatening diseases, whose clinical severity parallels the degree of immunosuppression. The existence of a strict interplay between HCMV and the immune system has led many to hypothesize that HCMV could also be involved in autoimmune diseases (ADs). Indeed, signs of active viral infection were later found in a variety of different ADs, such as rheumatological, neurological, enteric disorders, and metabolic diseases. In addition, HCMV infection has been frequently linked to increased production of autoantibodies, which play a driving role in AD progression, as observed in systemic lupus erythematosus (SLE) patients. Documented mechanisms of HCMV-associated autoimmunity include molecular mimicry, inflammation, and nonspecific B-cell activation. In this review, we summarize the available literature on the various ADs arising from or exacerbating upon HCMV infection, focusing on the potential role of HCMV-mediated immune activation at disease onset.

Chemical exposure-induced systemic fibrosing disorders: Novel insights into systemic sclerosis etiology and pathogenesis

Numerous drugs and chemical substances are capable of inducing exaggerated tissue fibrotic responses. The vast majority of these agents cause localized fibrotic tissue reactions or fibrosis confined to specific organs. Although much less frequent, chemically-induced systemic fibrotic disorders have been described, sometimes occurring as temporally confined outbreaks. These include the Toxic Oil Syndrome (TOS), the Eosinophilia-Myalgia Syndrome (EMS), and Nephrogenic Systemic Fibrosis (NSF). Although each of these disorders displays some unique characteristics, they all share crucial features with Systemic Sclerosis (SSc), the prototypic idiopathic systemic fibrotic disease, including vasculopathy, chronic inflammatory cell infiltration of affected tissues, and cutaneous and visceral tissue fibrosis. The study of the mechanisms and molecular alterations involved in the development of the chemically-induced systemic fibrotic disorders has provided valuable clues that may allow elucidation of SSc etiology and pathogenesis. Here, we review relevant aspects of the TOS, EMS, and NSF epidemic outbreaks of chemically-induced systemic fibrosing disorders that provide strong support to the hypothesis that SSc is caused by a toxic or biological agent that following its internalization by endothelial cells induces in genetically predisposed individuals a series of molecular alterations that result in the development of SSc clinical and pathological alterations.

Putative functional pathogenic autoantibodies in systemic sclerosis

Systemic sclerosis (scleroderma, SSc) is a systemic disease characterized by vascular lesions, fibrosis, and circulating autoantibodies. A complex interplay between innate and adaptive immunity, and with regard to the latter, between humoral and cellular immunity, is believed to be involved in SSc pathogenesis. Lately, close attention has been paid to the role of B cells which, once activated, release profibrotic cytokines, promote profibrotic Th2 differentiation, and produce autoantibodies. Several novel interesting autoantibodies, targeting antigens within the extracellular matrix or on the cell surface, rather than the nuclear antigens of canonical SSc-autoantibodies, have been recently described in patients with SSc. As they show stimulatory or inhibitory activity or react with structures involved in the pathogenesis of SSc lesions, they can be considered as potentially pathogenic. In this paper, we will review those which have been better characterized.

Occupational silica exposure in an Australian systemic sclerosis cohort

Objective

To determine the frequency of self-reported occupational exposure to silica in SSc patients enrolled in the Australian Scleroderma Cohort Study, and to compare the disease characteristics of the silica-exposed patients with those of the non-exposed patients.

Method

Data collected over a 12-year period from 1670 SSc patients were analysed. We compared the demographic and clinical characteristics of those who reported occupational silica exposure with those who did not. A subgroup analysis of male patients was performed, as well as a multivariable analysis of correlates of silica exposure.

Results

Overall, 126 (7.5%) of the cohort reported occupational silica exposure. These individuals were more likely to be male (73 of 231, i.e. 31.6% males exposed) and to have worked in mining and construction industries. Those who reported silica exposure were younger at the onset of SSc skin involvement [odds ratio (OR) 0.9, P = 0.02], of male gender (OR 14.9, P &lt; 0.001), have joint contractures (OR 1.8, P = 0.05) and have higher physical disability as defined by scleroderma HAQ (OR 1.4, P = 0.01).

Conclusion

The highest percentage of silica exposure was found in males. These patients were more likely to have the presence of certain clinical manifestations and Scl-70 antibody, which is known to confer a poor prognosis. These findings support the association between occupational silica exposure and the subsequent development of SSc. Further investigation is required to describe the range of clinical manifestations and disease course, including prognosis and treatment response, in those diagnosed with occupationally induced SSc compared with idiopathic SSc.

Systemic sclerosis in an anaesthetist

Introduction

Systemic sclerosis is a potentially devastating disease in which the aetiology and pathogenesis has not yet been fully understood. It has been associated with occupational exposure to silica, vinyl chloride, solvents and other chemical agents.

Case summary

In this paper, we present the case of an anaesthetist who developed scleroderma after an occupational exposure to volatile anaesthetic gases (halothane, sevoflurane, isoflurane and enflurane) in operating theatres with poor scavenging systems and we discuss the possible causal link between occupational exposure and the disease.

Conclusions

The case reported is the second that we are aware of in recent years. Reporting scleroderma cases in workers may be the first step in assessing the causal link between occupational exposure to anaesthetic gases and the disease.

Is exposure to environmental factors associated with a characteristic clinical and laboratory profile in systemic sclerosis? A retrospective analysis

To identify environmental factors (EF) in a large cohort of patients with systemic sclerosis (SSc) analyzing their clinical and laboratory presentation. A cohort of consecutive patients attended at a single Brazilian SSc outpatient clinic was analyzed regarding EF. Data were analyzed according to clinical, demographic and laboratory characteristics, as well as SSc subtype. In a cohort of 662 patients, 70 (10.6%) had known previous exposure to EF, predominantly organic solvents (51.4%), silica (20%), silicone (12.9%) and pesticides (11.4%). In the SSc cohort, patients with EF had a significantly higher frequency of male gender (p < 0.01), African-Brazilian ethnicity (p = 0.01), myopathy (p = 0.02), and pigmentary disorders (p = 0.04), with shorter disease duration (p = 0.01). When SSc subtypes were analyzed separately, there was positive association with male gender in limited (p < 0.01) and diffuse (p < 0.01) SSc, as well as African-Brazilian ethnicity (p = 0.04), severe interstitial lung disease (p < 0.01), myopathy (p = 0.02) and SD pattern at nailfold capillaroscopy (p = 0.01) in limited SSc, and negative association with esophageal hypomotility (p < 0.01) and ANA positivity (p = 0.02) in diffuse SSc. Multiple regression analyses showed that myopathy was independently associated with previous exposure to EF (OR = 2.09; 95% CI 1.15-3.82), especially silica exposure (OR = 3.09; 95% CI 1.67-5.73). This study showed that SSc patients with previous exposure to EF may have some specific clinical characteristics, mainly a higher frequency of myopathy, also showing more severe ILD, preferably in male and African-Brazilian patients, associated with a lower frequency of ANA positivity.

Pathogenic Roles of Autoantibodies and Aberrant Epigenetic Regulation of Immune and Connective Tissue Cells in the Tissue Fibrosis of Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a multi-system autoimmune disease with tissue fibrosis prominent in the skin and lung. In this review, we briefly describe the autoimmune features (mainly autoantibody production and cytokine profiles) and the potential pathogenic contributors including genetic/epigenetic predisposition, and environmental factors. We look in detail at the cellular and molecular bases underlying tissue-fibrosis which include trans-differentiation of fibroblasts (FBs) to myofibroblasts (MFBs). We also state comprehensively the pro-inflammatory and pro-fibrotic cytokines relevant to MFB trans-differentiation, vasculopathy-associated autoantibodies, and fibrosis-regulating microRNAs in SSc. It is conceivable that tissue fibrosis is mainly mediated by an excessive production of TGF-β, the master regulator, from the skewed Th2 cells, macrophages, fibroblasts, myofibroblasts, and keratinocytes. After binding with TGF-β receptors on MFB, the downstream Wnt/β-catenin triggers canonical Smad 2/3 and non-canonical Smad 4 signaling pathways to transcribe collagen genes. Subsequently, excessive collagen fiber synthesis and accumulation as well as tissue fibrosis ensue. In the later part of this review, we discuss limited data relevant to the role of long non-coding RNAs (lncRNAs) in tissue-fibrosis in SSc. It is expected that these lncRNAs may become the useful biomarkers and therapeutic targets for SSc in the future. The prospective investigations in the development of novel epigenetic modifiers are also suggested.

Antigen-specific humoral responses against Helicobacter pylori in patients with systemic sclerosis

Helicobacter pylori (Hp) is a likely trigger of systemic sclerosis (SSc), but systemic antigen-specific antibody (Ab) responses in a well-defined cohort of SSc patients have not been thoroughly assessed. Line immunoassay and immunoblotting testing Abs against 15 Hp antigens were performed in 91 SSc patients and 59 demographically matched healthy controls (HCs). Results were validated in an independent cohort of 35 SSc patients. Anti-Hp positivity was detected in 67% SSc patients vs 76.3% HCs. Among anti-Hp (+) individuals, anti-p67-FSH was less frequent in SSc than HCs (p = 0.016), whereas reactivity to the remaining 14 Hp antigens did not differ between patients and HCs. Anti-p67 Abs were less frequent in diffuse cutaneous SSc (dcSSc) compared with HCs (p = 0.018). Anti-p57 and anti-p33 Ab levels were lower in SSc vs HCs (p = 0.007 and p = 0.035, respectively). Anti-p57 and anti-p33 Ab levels were lower in limited cutaneous SSc (lcSSc) (p = 0.010) and dcSSc (p = 0.024), respectively, compared with HCs. Anti-p50 and anti-p17 Ab titers tended to be higher in dcSSc than in lcSSc. Sera from the independent SSc cohort showed comparable results. Anti-VacA Abs were more frequent in pulmonary arterial hypertension (p = 0.042), and anti-p30 Abs were more frequent in calcinosis (p = 0.007), whereas anti-VacA Ab levels were higher in lung fibrosis (p = 0.02). In conclusion, anti-Hp Abs are neither more frequent nor elevated in SSc compared with healthy population, the only exception being the higher frequency and levels of anti-VacA Abs in pulmonary hypertension and lung fibrosis, respectively. These results suggest that Hp is unlikely to be involved in the development of SSc.

Aryl hydrocarbon receptor signals attenuate lung fibrosis in the bleomycin-induced mouse model for pulmonary fibrosis through increase of regulatory T cells

BACKGROUND

Interstitial lung disease (ILD) is a serious complication of connective tissue diseases (CTDs). Although immune dysregulation triggered by genetic and environmental factors is thought to provoke inflammation and subsequent fibrosis, precise mechanisms of these processes remain unclear. Recent reports suggest that activation of aryl hydrocarbon receptor (AhR) signals by various ligands such as tryptophan derivatives can induce hyper-immune responses and are involved in autoimmunity. We investigated the effects of AhR signals on the process of lung fibrosis and changes in immunological features using a bleomycin (BLM)-induced lung fibrosis mouse model.

METHODS

BLM was administered intratracheally to C57BL/6JJcl mice and either 5,11-dihydroindolo[3,2-b]carbazole-6-carboxaldehyde (FICZ), a natural AhR ligand, or vehicle was subsequently injected intraperitoneally on day 0, 1, and 2 from BLM administration. Mice were sacrificed at week 3, and lung fibrosis was quantified by the histological changes using the Ashcroft score and deposition of soluble collagen levels in the lung using Sircol assay. The population of immune cells infiltrated into the lungs was analyzed using flow cytometry.

RESULTS

Both the Ashcroft score and soluble collagen level in FICZ-treated mice were significantly lower than those in the vehicle group. Moreover, the survival rate of FICZ-treated mice was significantly higher than that of control mice during the 3 weeks after treatment. Interestingly, flow cytometric analysis revealed that the number of CD4⁺Foxp3⁺ regulatory T cells (Tregs) was significantly increased and CD4⁺IFNγ⁺ and γδ⁺IL-17A⁺ T cells were decreased in the lungs of FICZ-treated mice, while the total number of T, B, and NK cells were unaffected by FICZ treatment.

CONCLUSIONS

Our findings suggest that stimulation of AhR signals attenuated lung fibrosis by increasing Tregs and suppressing inflammatory T cell subsets in a BLM-induced fibrosis model. AhR signaling pathways may therefore be useful therapeutic targets for connective tissue disease-associated ILD.

Epigenetics of scleroderma: Integrating genetic, ethnic, age, and environmental effects

Scleroderma or systemic sclerosis is thought to result from the interplay between environmental or non-genetic factors in a genetically susceptible individual. Epigenetic modifications are influenced by genetic variation and environmental exposures, and change with chronological age and between populations. Despite progress in identifying genetic, epigenetic, and environmental risk factors, the underlying mechanism of systemic sclerosis remains unclear. Since epigenetics provides the regulatory mechanism linking genetic and non-genetic factors to gene expression, understanding the role of epigenetic regulation in systemic sclerosis will elucidate how these factors interact to cause systemic sclerosis. Among the cell types under tight epigenetic control and susceptible to epigenetic dysregulation, immune cells are critically involved in early pathogenic events in the progression of fibrosis and systemic sclerosis. This review starts by summarizing the changes in DNA methylation, histone modification, and non-coding RNAs associated with systemic sclerosis. It then discusses the role of genetic, ethnic, age, and environmental effects on epigenetic regulation, with a focus on immune system dysregulation. Given the potential of epigenome editing technologies for cell reprogramming and as a therapeutic approach for durable gene regulation, this review concludes with a prospect on epigenetic editing. Although epigenomics in systemic sclerosis is in its infancy, future studies will help elucidate the regulatory mechanisms underpinning systemic sclerosis and inform the design of targeted epigenetic therapies to control its dysregulation.

A comprehensive analysis of antigen-specific antibody responses against human cytomegalovirus in patients with systemic sclerosis

Anti-human cytomegalovirus (HCMV) antibodies are considered triggers of systemic sclerosis (SSc), but such a hypothesis has been assessed in limited sub-dominant epitopes. Our aim was to systematically assess the potential association of HCMV antibodies targeting most immunodominant and subdominant viral antigens, as this would reveal immunopathogenic associations. Our study included 110 SSc patients, 60 multiple sclerosis (MS) patients, and 51 healthy controls (HC). Anti-HCMV abs were tested by immunoblotting. IgG anti-HCMV was broader in SSc and MS compared to HC. Anti- UL57 and UL55 were more frequent in SSc versus MS forms. Reactivity to multiple viral antigens was more frequent in SSc than MS forms. Anti-viral antibodies levels were higher in specific autoantibody-positive SSc patients compared to seronegative cases. In conclusion, more prevalent and/or stronger antigen-specific HCMV responses are noted in SSc compared to controls, implying a role of these viral responses in SSc development.

Association Between Exposure to Heavy Metals and Systemic Sclerosis: the Levels of Al, Cd, Hg, and Pb in Blood and Urine of Patients

Systemic sclerosis (SSc) is a multisystem connective tissue disease; exogenous factors-including heavy metals-may have a role in the disease pathogenesis. In this context, a study on the quantification of Al, Cd, Hg, and Pb in blood and urine of 27 SSc patients and 30 controls was carried out. Main findings were that Al was significantly depleted in blood and increased in urine of SSc patients respect to controls; and Pb was found slightly increased in blood and significantly decreased in SSc group. In addition, higher Hg levels in urine were found in SSc subjects with the higher severity of the disease. Females showed the most marked differences in the levels of blood Al, blood Pb, and urine Cd between patients and controls. Smoking, hobby, ingestion of contaminated food, job exposure may contribute to the bodily levels of Al, Hg, Pb in SSc patients. The results indicated that low, chronic, and multiple exposures to heavy metals-also through habits, diet, and environment-may influence the risk for SSc.

Human leukocyte antigen (HLA)-DRB1 allele polymorphisms and systemic sclerosis

Objectives: Human leukocyteantigen (HLA) is the most important gene for immune system regulation. Although studies have evaluated the association between HLA-DRB1 allele polymorphisms and systemic sclerosis (SSc), their results are still controversial. We performed a meta-analysis to assess the association of HLA-DRB1 alleles with risk of SSc.Methods: Electronic database were systematically searched for articles, a total of 11 case-control studies including 3268 cases and 5548 controls were analyzed. Odds ratio (ORs) and 95% confidence intervals were used to assess the association of HLA-DRB1 alleles with SSc. The relationship between SSc-related autoantibodies and DRB1 alleles was also analyzed.Results: In the overall analysis, four alleles (DRB1*04:03, DRB1*08, DRB1*11, and DRB1*11:04) increased the risk of SSc; however, five alleles (DRB1*07, DRB1*11:01, DRB1*13, DRB1*13:01, and DRB1*14) had the opposite effect. Analysis of subgroups by ethnicity indicate that DRB1*11:01 and DRB1*13:01 confer a protective effect in Caucasians, while DRB1*11:04 was associated with a higher risk of SSc. For Asian, DRB1*13:02 was found to be a protective factor. In addition, the frequency of DRB1*11:04 alleles was significantly increased in ATA⁺ SSc patients compared with ATA^- SSc patients.Conclusion: DRB1*04:03, DRB1*08, DRB1*11, and DRB1*11:04 were associated with the risk of SSc. Additionally, DRB1*11 and DRB1*11:04 were association with ATAs.

Intriguing Relationships Between Cancer and Systemic Sclerosis: Role of the Immune System and Other Contributors

Systemic sclerosis (SSc) is an autoimmune connective tissue disorder, characterized by multisystem involvement, vasculopathy, and fibrosis. An increased risk of malignancy is observed in SSc (including breast and lung cancers), and in a subgroup of patients with specific autoantibodies (i.e., anti-RNA polymerase III and related autoantibodies), SSc could be a paraneoplastic syndrome and might be directly related to an immune response against cancer. Herein, we reviewed the literature, focusing on the most recent articles, and shed light onto the potential relationship between cancer and scleroderma regarding temporal and immunological dimensions.

Risk factors for the development of systemic sclerosis: a systematic review of the literature

OBJECTIVES

Although numerous studies have investigated the roles of various genetic, epigenetic and environmental factors that may impact its aetiology, SSc is still regarded as an idiopathic disease. Given that there is significant heterogeneity in what has been proposed to influence the development of SSc, this systematic review was conducted to assess the impacts of different factors on the aetiology of scleroderma.

METHODS

The search was performed in the PubMed, CINAHL and SCOPUS databases on 17 May 2017. Any study that made explicit reference to scleroderma or SSc that had information about the risk factors or epidemiology of the disease was included. The extracted outcome variables were prevalence, gender preponderance, geographical distribution, family history and various proposed environmental risk factors.

RESULTS

One thousand five hundred and seventy-four articles were screened for eligibility. Thirty-four articles were eligible for the systematic literature review.

CONCLUSION

Age between 45 and 64 years, female sex, positive family history and exposure to silica were found to be risk factors. There were conflicting findings regarding the impact of exposure to organic solvents and microchimerism. No relationship between infectious agents, alcohol consumption or cigarette smoking and the development of SSc was identified.

Systemic sclerosis

Systemic sclerosis, also called scleroderma, is an immune-mediated rheumatic disease that is characterised by fibrosis of the skin and internal organs and vasculopathy. Although systemic sclerosis is uncommon, it has a high morbidity and mortality. Improved understanding of systemic sclerosis has allowed better management of the disease, including improved classification and more systematic assessment and follow-up. Additionally, treatments for specific complications have emerged and a growing evidence base supports the use of immune suppression for the treatment of skin and lung fibrosis. Some manifestations of the disease, such as scleroderma renal crisis, pulmonary arterial hypertension, digital ulceration, and gastro-oesophageal reflux, are now treatable. However, the burden of non-lethal complications associated with systemic sclerosis is substantial and is likely to become more of a challenge. Here, we review the clinical features of systemic sclerosis and describe the best practice approaches for its management. Furthermore, we identify future areas for development.

Human cytomegalovirus (HCMV) UL44 and UL57 specific antibody responses in anti-HCMV-positive patients with systemic sclerosis

The role of human cytomegalovirus (HCMV) has been postulated as a trigger of systemic sclerosis (SSc). The aim of the study was to assess the prevalence of antibodies against HCMV UL44 and UL57 antigens not tested in the past. Sixty SSc patients, 40 multiple sclerosis and 17 normal controls (NCs), all anti-HCMV positive, were tested by immunoblotting. Reactivity to HCMV antigens, expressed as arbitrary units (AUs), was assessed for correlation with clinical and immunological parameters, including types of SSc-related autoantibodies. Anti-UL44 and anti-UL57 HCMV antibodies were present in 3/60 (5%) and 58/60 (96.7%) SSc patients, respectively (p < 0.001). Anti-UL57 antibodies were present in 35/40 (87.5%) MS patients and 16/17 (94.1%) NCs (SSc vs MS, MS vs NC, p = ns). Strong (50-75 AU) and very strong (75-100 AU) anti-UL57 immunoreactivity was found in 24 (41.4%) and 22 (37.9%) SSc patients, respectively (p = ns). Dilution experiments showed anti-UL57 antibody persistence in up to 1/5000. Overall, there was no difference in the frequency or the magnitude of anti-UL57 immunoreactivity between diffuse cutaneous systemic sclerosis and limited cutaneous systemic sclerosis patients (96.67 vs 96.67%; 65.45 ± 20.19 vs 64.31 ± 21.11 AU, p > 0.05) but strong anti-UL57 reactivity were more frequent in SSc compared to NCs (p = 0.007). Anti-UL57 reactivity was not inhibited by SSc-specific autoantigens. Anti-UL57 seropositivity did not correlate with demographic, clinical or immunological features of SSc. Anti-HCMV UL57 antibodies are universally present in anti-HCMV-positive patients with SSc, while those against UL44 are rarely seen. Because anti-UL57 lack disease specificity and are not involved in cross-reactive responses, their immunopathogenetic potential is to be questioned.

Rheumatic diseases induced by drugs and environmental factors: the state-of-the-art - part one

The majority of rheumatic diseases belong to the group of autoimmune diseases and are associated with autoantibody production. Their etiology is not fully understood. Certain medications and environmental factors may have an influence on the occurrence of rheumatic diseases. Establishing a cause-effect relationship between a certain factor and disease induction is not always simple. It is important to administer the drug continuously or monitor exposure to a given factor in the period preceding the onset of symptoms. The lack of previously diagnosed autoimmune disease, or finally the lack of symptoms within a few weeks/months after discontinuation of the drug/cessation of exposure, is also important. The most frequently mentioned rheumatic diseases caused by drugs and environmental factors include systemic lupus erythematosus, scleroderma, systemic vasculitis, polymyositis, dermatomyositis, and Sjögren's syndrome. The objective of this study is to summarize current knowledge on rheumatic diseases induced by drugs and environmental factors.

Fructose Malabsorption in Systemic Sclerosis

The deleterious effect of fructose, which is increasingly incorporated in many beverages, dairy products, and processed foods, has been described; fructose malabsorption has thus been reported in up to 2.4% of healthy subjects, leading to digestive clinical symptoms (eg, pain, distension, diarrhea). Because digestive involvement is frequent in patients with systemic sclerosis (SSc), we hypothesized that fructose malabsorption could be responsible for intestinal manifestations in these patients. The aims of this prospective study were to: determine the prevalence of fructose malabsorption, in SSc; predict which SSc patients are at risk of developing fructose malabsorption; and assess the outcome of digestive symptoms in SSc patients after initiation of standardized low-fructose diet. Eighty consecutive patients with SSc underwent fructose breath test. All SSc patients also completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated. The prevalence of fructose malabsorption was as high as 40% in SSc patients. We also observed a marked correlation between the presence of fructose malabsorption and: higher values of GSS score of digestive symptoms (P = 0.000004); and absence of delayed gastric emptying (P = 0.007). Furthermore, in SSc patients with fructose malabsorption, the median value of GSS score of digestive symptoms was lower after initiation of standardized low-fructose diet (4 before vs. 1 after; P = 0.0009). Our study underscores that fructose malabsorption often occurs in SSc patients. Our findings are thus relevant for clinical practice, highlighting that fructose breath test is a helpful, noninvasive method by: demonstrating fructose intolerance in patients with SSc; and identifying the group of SSc patients with fructose intolerance who may benefit from low-fructose diet. Interestingly, because the present series also shows that low-fructose diet resulted in a marked decrease of gastrointestinal clinical manifestations in SSc patients with fructose malabsorption, our findings underscore that fructose malabsorption may play a significant role in the onset of gastrointestinal symptoms in these patients. Finally, we suggest that fructose malabsorption may be due to reduced fructose absorption by enterocytes, impaired enteric microbiome, and decreased intestinal permeability.