Update on the epidemiology, risk factors, and disease outcomes of systemic sclerosis

Prevalence and predictors of small intestinal bacterial overgrowth in systemic sclerosis: a systematic review and meta-analysis

The reported prevalence of small intestinal bacterial overgrowth (SIBO) among patients with systemic sclerosis (SSc) is highly variable. We conducted this systematic review and meta-analysis to estimate the prevalence and identify predictors of SIBO in SSc by summarizing all of the available data. A comprehensive literature search of the PubMed, Cochrane Library, and EMBASE databases from inception to July 2020 was conducted for studies correlating SIBO with SSc. Studies were screened, and relevant data were extracted and analyzed. The pooled prevalence of SIBO among SSc patients and the odds ratio (OR) of SIBO among SSc patients compared with healthy controls were calculated. Furthermore, predictors of SIBO in SSc were evaluated. Fourteen studies containing 700 SSc patients and 217 healthy controls met the inclusion criteria. The pooled prevalence of SIBO in SSc was 34% (95% CI 27-42%). The OR of SIBO in SSc patients was 12.51 (95% CI 6.51-24.03) compared with the healthy controls. Subgroup analyses showed that the prevalence of SIBO in SSc was higher in studies using the lactulose hydrogen breath test (LHBT) for diagnosis (56%, 95% CI 46-67%) compared with those that used the glucose hydrogen breath test (GHBT) (27%, 95%CI 20-35%) and a jejunal aspirated culture (JAC) (35%, 95%CI 25-51%). The prevalence of SIBO in SSc was higher in studies conducted in Western countries (38%, 95% CI 31-47%) than those conducted in Asian countries (15%, 95%CI 10-23%), and the prevalence of SIBO in the SSc population defined by ACR-EULAR 2013 (50%, 95% CI 0.21-0.79) was higher than the prevalence defined by ACR 1980 (30%, 95% CI 0.17-0.42) or other criteria (32%, 95% CI 0.16-0.48) Moreover, the risk of diarrhea was higher in SSc patients with SIBO than those without SIBO (OR 8.82, 95% CI 4.09-19, P < 0.00001); gender, SSc subset, digital ulcer, and pulmonary fibrosis do not seem to be associated with SIBO in SSc. Antibiotic therapy seems to be effective with SIBO in SSc patients. Approximately one-third of SSc patients tested positive for SIBO with a significantly increased risk over the controls. The prevalence of SIBO in SSc varied according to the SIBO diagnostic test performed, geographic area, and SSc diagnostic criteria. The presence of diarrhea may be a predictor of SIBO in SSc. Antibiotic treatment can lead to eradication of SIBO and gastrointestinal symptomatic improvement in SSc patients. Key Points • The pooled prevalence of SIBO in SSc patients was 34%, which varied according to the SIBO diagnostic test performed, geographic area and SSc diagnostic criteria. • The risk of SIBO in SSc was increased by nearly thirteenfold compared to the healthy controls. • Diarrhoea, but not gender, SSc subset, digital ulcer and pulmonary fibrosis, was associated with SIBO in SSc patients. • For SSc patients with SIBO, antibiotic treatment can lead to eradication of SIBO and gastrointestinal symptomatic improvement.

[Monocentric study on pharmaceuticals taken by patients to treat systemic sclerosis]

INTRODUCTION

Pharmaceutical prescription in systemic sclerosis is guided by national and international recommendations. This study's primary objective was to describe and analyze these prescriptions among patients of our cohort. We also aimed to assess drug compliance among our patients.

METHODS

This is a monocentric observational study on two cohorts of patients with systemic sclerosis; a primary cohort comprising ambulatory patients, who were prospectively included, with exhaustive prescription's data collection; and a secondary cohort included patients asked to fill in a self-questionnaire on treatment compliance.

RESULTS

The main cohort included 157 patients, including 31 cases of diffuse systemic sclerosis. A vasodilator drug for Raynaud's phenomenon was prescribed in 75 patients (47.9%) and a specific treatment for pulmonary arterial hypertension in 10 patients (6.4%). Immuno-modulators/immunosuppressants was prescribed in 62 patients (39.5%), who received prednisone (n=37, 23.6%), mycophenolate mofetil (n=14, 8.9%), hydroxychloroquine (n=12, 7.6%) and colchicine (n=22, 14%). Treatment for "gastro-intestinal tract involvement" was prescribed for 106 patients (67.5%) and treatment of a scleroderma renal crisis with an angiotensin-converting enzyme inhibitor for 6 patients (3.8%). Among the 42 patients in the secondary cohort, 21.4% reported a good compliance, mostly older patients (P=0.045) or those who had not experienced adverse events (P=0.009).

CONCLUSION

This study provides original real-life data illustrating the heterogeneity of prescription habits in systemic sclerosis. As previously reported, treatment compliance was insufficient.

An Exploratory Study of the Use of the Electronic Health Records of Hypertensive Patients to Support the Primary Prevention of Stroke in Shanghai

Background

The value of identifying and targeting population demographics at high risk of stroke based on patient-reported outcomes (PROs) with electronic health records (EHRs) in Shanghai is largely undiscovered.

Aim

To test the hypothesis that establishing an evidence-based support system composed of PROs integrated with EHRs could be effective at identifying individuals at high risk of suffering from stroke.

Methods

The patients included in this study joined the hypertensive patient management system from 2014 to 2018. We merged the Hypertension Patients Management Database and the Diabetes Mellitus Patients Management Database of Shanghai Jiading district, then kept the hypertension patients with or without diabetes. We subsequently performed a screen analysis utilizing EHRs to target the population with any risk factor for stroke, namely, hypertension, diabetes mellitus, obesity, smoking and physical inactivity. We also calculated the distribution of each risk factor and the combinations of risk factors.

Results

In the Jiading District of Shanghai, 46,580 hypertensive patients with complete baseline information joined the hypertensive patient management system from 2014 to 2018. The majority of the patients were aged above 60 years old. Physical inactivity (83.24%), smoking (24.07%), diabetes (16.87%), and obesity (12.23%) were highly prevalent in hypertensive participants. Approximately 4377 patients were diagnosed with hypertension exclusively, accounting for 9.70% of the total number of patients in this study. Meanwhile, approximately 52.47% of the patients were diagnosed with two concurrent risk factors, and 38.13% of the patients had hypertension, meaning that 17,762 patients could be labeled as the high-risk population for stroke according to the criteria established by the National Stroke Screening Survey.

Conclusion

Our exploratory findings demonstrate the feasibility of pinpointing and targeting populations at high risk of stroke using the EHRs of hypertensive patients.

The Epidemiology and Clinical Manifestations of Autoimmunity in Selective IgA Deficiency

Selective immunoglobulin A deficiency (SIgAD) is the most common primary immunodeficiency, defined as an isolated deficiency of IgA (less than 0.07 g/L). Although the majority of people born with IgA deficiency lead normal lives without significant pathology, there is nonetheless a significant association of IgA deficiency with mucosal infection, increased risks of atopic disease, and a higher prevalence of autoimmune disease. To explain these phenomena, we have performed an extensive literature review to define the geoepidemiology of IgA deficiency and particularly the relative risks for developing systemic lupus erythematosus, hyperthyroidism, hypothyroidism, type 1 diabetes mellitus, Crohn's disease, ulcerative colitis, rheumatoid arthritis, juvenile idiopathic arthritis, ankylosing spondylitis, and vitiligo; these diseases have strong data to support an association. We also note weaker associations with scleroderma, celiac disease, autoimmune hepatitis, immune thrombocytopenic purpura, and autoimmune hemolytic anemia. Minimal if any associations are noted with myasthenia gravis, lichen planus, and multiple sclerosis. Finally, more recent data provide clues on the possible immunologic mechanisms that lead to the association of IgA deficiency and autoimmunity; these lessons are important for understanding the etiology of autoimmune disease.

Co-existence of Marfan syndrome and systemic sclerosis: A case report and a hypothesis suggesting a common link

FBN1 gene encodes for the connective tissue protein fibrillin-1 which can also regulate the profibrotic cytokine transforming growth factor (TGF)-ß1. Mutations in the FBN1 gene cause Marfan syndrome (MFS), a genetic condition with defective connective tissues. FBN1 haplotypes and single nucleotide polymorphisms have also been reported to be associated with systemic sclerosis (SSc), a connective tissue disease characterized by fibrosis of multiple organs. Furthermore, the duplication of the Fbn1 gene causes a SSc-like disease in the TsK1 mouse model. To the best of our knowledge, there are no reports of MFS and SSc co-existing in a patient. Here, we describe a 46-year-old woman who presented with cardiac failure. She had a family history of MFS. Physical examination revealed marfanoid habitus and scleroderma features. Echocardiography demonstrated dilated cardiomyopathy with aortic root dilatation, aortic regurgitation and mitral regurgitation. Cardiac magnetic resonance imaging was consistent with dilated cardiomyopathy, mid-wall fibrosis at basal septal wall and dilated aortic root. Extractable nuclear antigen panel detected anti-Scl 70. She fulfilled Ghent criteria for MFS and satisfied American College of Rheumatology/ European League Against Rheumatism classification criteria for SSc. Although we do not have the FBN1 sequence in our patient, the co-existence of MFS and SSc in this patient raises the possibility of co-existence of distinct mutations in the FBN1 gene that could affect TGF-β signaling differently, resulting in divergent pathologic consequences - loss of structural integrity in MFS versus increased extracellular matrix deposition in SSc, and different clinical manifestations.

Mechanisms of Environment-Induced Autoimmunity

Although numerous environmental exposures have been suggested as triggers for preclinical autoimmunity, only a few have been confidently linked to autoimmune diseases. For disease-associated exposures, the lung is a common site where chronic exposure results in cellular toxicity, tissue damage, inflammation, and fibrosis. These features are exacerbated by exposures to particulate material, which hampers clearance and degradation, thus facilitating persistent inflammation. Coincident with exposure and resulting pathological processes is the posttranslational modification of self-antigens, which, in concert with the formation of tertiary lymphoid structures containing abundant B cells, is thought to promote the generation of autoantibodies that in some instances demonstrate major histocompatibility complex restriction. Under appropriate gene-environment interactions, these responses can have diagnostic specificity. Greater insight into the molecular and cellular requirements governing this process, especially those that distinguish preclinical autoimmunity from clinical autoimmunedisease, may facilitate determination of the significance of environmental exposures in human autoimmune disease.

Pulmonary involvement in systemic sclerosis: exploring cellular, genetic and epigenetic mechanisms

Systemic sclerosis (SSc) is a chronic progressive autoimmune disease characterized by immune inflammation, vasculopathy, and fibrosis. There are still numerous uncertainties in the understanding of disease initiation and progression. Pulmonary involvement in SSc, and particularly pulmonary fibrosis, is critical for all organ systems affections in this disease. This review is aimed to describe and analyze new findings in the pathophysiology of SSc-associated pulmonary involvement and to explore perspective diagnostic and therapeutic strategies. A myriad of cellular interactions is explored in the dynamics of progressive interstitial lung disease (ILD) and pulmonary hypertension (PH) in SSc. The role of exosomes, microvesicles, and apoptotic bodies is examined and the impact of micro and long non-coding RNAs, DNA methylation, and histone modification in SSc is discussed.

The efficacy and safety of fecal microbiota transplantation in the treatment of systemic sclerosis: A protocol for systematic review and meta analysis

BACKGROUND

Systemic sclerosis (SSc) is 1 of the most complex systemic autoimmune diseases.Accumulating evidence suggests that gut microbiota affect the development and function of the immune system and may play a role in the pathogenesis of autoimmune diseases. This new paradigm raises the possibility that many diseases result, at least partially, from microbiota-related dysfunction. This understanding invites the investigation of fecal microbiota transplantation (FMT) in the treatment of SSc. However, no study has specifically and systematically investigated the efficacy and safety of FMT in the treatment of SSc. Thus, this study will systematically and comprehensively appraise the efficacy and safety of FMT in the treatment of SSc.

METHODS

We will search the following sources without restrictions for date, language, or publication status: PubMed, Web of Science,Cochrane Central Register of Controlled Trials (CENTRAL) Cochrane Library, EMBASE and China National Knowledge Infrastructure. We will apply a combination of Medical Subject Heading (MeSH) and free-text terms incorporating database-specific controlled vocabularies and text words to implement search strategies. We will also search the ongoing trials registered in the World Health Organization's International Clinical Trials Registry Platform. Besides, the previous relevant reviews conducted on FMT for SSc and reference lists of included studies will also be searched.

RESULTS

This study will provide a reliable basis for the treatment of SSc with FMT.

CONCLUSIONS

The findings will be an available reference to evaluate the efficacy and safety of FMT in the treatment of SSc.

REGISTRATION NUMBER

INPLASY202060019.

Identification of Biomarkers Related to Systemic Sclerosis With or Without Pulmonary Hypertension Using Co-expression Analysis

Systemic sclerosis (SSc), also known as scleroderma, is an autoimmune disease with multiple system involvement, and pulmonary complications, including pulmonary hypertension (PH), are leading causes of death. This study aimed to develop early biomarkers to distinguish SSc with or without PH from normal population using bioinformatics approaches. The gene expression profile GSE22356, which contains 10 SSc samples with PH, 10 SSc samples without PH, and 10 normal samples, was obtained from the Gene Expression Omnibus database. First, we constructed co-expression networks and identified critical gene modules using the weighted gene co-expression network analysis. Then, functional enrichment analysis of significant modules was performed. Finally, the "real" hub gene was screened out by intramodule analysis and protein-protein interaction networks, and the receiver operating characteristic analysis was conducted. A total of 5046 genes were screened out to construct co-expression networks, and 18 modules were identified. Of these modules, the turquoise module had a strong correlation with SSc only, whereas the midnightblue module showed an obvious positive correlation with SSc with PH. Functional enrichment analysis indicated that the turquoise module was mainly enriched in transcription of DNA template and its regulation and protein ubiquitination and involved in apoptosis and pyrimidine metabolism pathway. The midnightblue module was significantly associated with inflammatory and immune response and pathways in Staphylococcus aureus infection and Chagas disease. The "real" hub genes in the turquoise module were WDR36, POLR1B, and SRSF1, and those in midnightblue were TLR2 and TNFAIP6.

Systemic sclerosis-associated interstitial lung disease

Systemic sclerosis is an autoimmune connective tissue disease, which is characterised by immune dysregulation and progressive fibrosis that typically affects the skin, with variable internal organ involvement. It is a rare condition that affects mostly young and middle-aged women, resulting in disproportionate morbidity and mortality. Currently, interstitial lung disease is the most common cause of death among patients with systemic sclerosis, with a prevalence of up to 30% and a 10-year mortality of up to 40%. Interstitial lung disease is more common among African Americans and in people with the diffuse cutaneous form of systemic sclerosis or anti-topoisomerase 1 antibodies. Systemic sclerosis-associated interstitial lung disease most commonly presents with dyspnoea, cough, and a non-specific interstitial pneumonia pattern on CT scan, with a minority of cases fulfilling the criteria for usual interstitial pneumonia. The standard therapy has traditionally been combinations of immunosuppressants, particularly mycophenolate mofetil or cyclophosphamide. These immunosuppressants can be supplemented by targeted biological and antifibrotic therapies, whereas autologous haematopoietic stem-cell transplantation and lung transplantation are reserved for refractory cases.

Systemic sclerosis: Advances towards stratified medicine

Epidemiological studies reporting demographic, clinical and serological factors predictive of various outcomes in systemic sclerosis (SSc) range from the prediction of mortality to the development and progression of disease manifestations. However, predicting the disease trajectory in the individual patient is a challenging but important step towards a stratified approach to disease management. Recent technological advances provide the opportunity for new subgroupings of disease based on risk stratification, through the systematic analysis of high-dimensional clinical data combined with genes, their transcription products and their corresponding translated proteins. In addition, these variables offer a rich vein of research to identify non-invasive biomarkers for predicting organ involvement and to assess disease activity and response to therapy. Selection of patients with a clinical phenotype or molecular signature relevant to the therapy under study combined with recent efforts to standardise outcome measures, show promise for improving clinical trial design and the identification of effective targeted therapies.

Associations of Vitamin D Receptor Single Nucleotide Polymorphisms with Susceptibility to Systemic Sclerosis

BACKGROUND

This study aims to evaluate whether the Vitamin D receptor (VDR) gene polymorphisms were associated with systemic sclerosis (SSc) in a Chinese Han population.

METHODS

Using a hospital-based case-control study including 100 SSc patients and 100 healthy controls. Single nucleotide polymorphisms (SNPs) in the VDR region were genotyped by the improved multiplex ligase detection reaction (i MLDR) method. Haplotypes were also constructed after linkage disequilibrium (LD) analysis.

RESULTS

Eight SNPs (rs731236 (TaqI), rs2228570 (FokI), rs7975232 (ApaI), rs1544410 (BsmI), rs11574010 (Cdx2), rs739837 (BglI), rs757343 (Tru9I) and rs11168267) were included. There were significant differences between SSc patients and healthy individuals in ApaI and BglI genotype (both adjusted p = 0.008). Through the genotyping, significantly association of SSc were found for: dominant model of ApaI and BglI (both OR (95% CI) = 1.80 (1.03,3.16), p = 0.040). Furthermore, the elevation of erythrocyte sedimentation rate (ESR) had a higher percentage of BglI GT genotype frequency (p = 0.034) and dominant model of ApaI (p = 0.016) in SSc. There was high linkage disequilibrium was detected in BglI and ApaI polymorphisms (r² = 1.0, D' = 1.0), Tru9I and rs11168267 (r² = 0.926, D' = 0.969), respectively. No significant difference were found in these four haplotypes (all p >0.05). The correlation between VD levels and VDR gene polymorphisms was not statistically significant.

CONCLUSIONS

Our preliminary study indicates the ApaI and BglI genotype may possibly have a role in the pathogenesis of SSc patients. Dominant model of ApaI and BglI GT genotype frequency may be associated with the increased risk of ESR.

Prevalence of systemic sclerosis in Colombia: Data from the National Health Registry 2012–2016

Introduction:

Systemic sclerosis is an autoimmune disease that characteristically presents with fibrosis and vasculopathy. In Latin America, the information on the epidemiology of this disease is scarce and records are essential to know its behavior in the populations. In Colombia, the Ministry of Health uses the SISPRO tool to collect information on the unified national health system which offers nearly universal coverage (around 95%). This public information makes it possible to perform epidemiological studies on different diseases.

Objectives:

Using the SISPRO data corresponding to the years 2012–2016, we analyzed the prevalence and characteristics of patients with systemic sclerosis.

Methods:

A descriptive cross-sectional study was performed based on the SISPRO data; we used as keywords the diagnoses of the International Classification of Diseases related to the diagnosis of systemic sclerosis.

Results:

A total of 11,300 individuals diagnosed with systemic sclerosis were documented. The estimated prevalence was 23.7 cases per 100,000 inhabitants (based on a total population of 47,663,162); this disease is more frequent in the age group of 65–69 years in females (77%), and has a female:male ratio of 3.27:1.

Conclusion:

This study describes the epidemiological characteristics of systemic sclerosis in Colombia, based on official statistics from the Ministry of Health. The results provide a new vision of this disease in Latin America and open the door to future research, in order to better understand the particular characteristics of this disease in our country and our region.

Safety of fertility treatments in women with systemic autoimmune diseases (SADs)

Introduction: Systemic Autoimmune Diseases (SADs) include systemic lupus erythematosus, antiphospholipid antibody syndrome, rheumatoid arthritis, systemic sclerosis, Sjogren's syndrome, mixed connective tissue disease, idiopathic inflammatory myopathies and vasculitis. SADs often occur in women of childbearing age and can affect fertility. Both infertility treatments and fertility preservation techniques are thus often indicated. Areas covered: The literature regarding the safety of fertility-related drugs for both fertility preservation and infertility treatment in patients affected by SADs was reviewed. Based on current knowledge, all the options for fertility preservation should be contemplated in patients with SADs who are at risk for fertility loss, including GnRH analogue administration, oocyte/embryo vitrification and ovarian tissue cryopreservation. Similarly, if pregnancy is not contraindicated in a patient with a SAD, neither should be any fertility treatment. Expert opinion: Women with SADs should postpone conception until a stable disease has been achieved for at least 6 months. When infertility treatments are needed, women with antiphospholipid antibodies should receive concomitant anticoagulation. If in vitro fertilization/intra-cytoplasmic sperm injection and embryo transfer is required, ovarian hyperstimulation and the inherent risk of thrombosis should be eliminated by GnRH-agonist trigger and cycle segmentation. Counselling about adherence to anti-rheumatic therapy to prevent disease exacerbations is also critical.

Antibodies against specific extractable nuclear antigens (ENAs) as diagnostic and prognostic tools and inducers of a profibrotic phenotype in cultured human skin fibroblasts: are they functional?

BACKGROUND

The importance of systemic sclerosis (SSc) autoantibodies for diagnosis has become recognized by their incorporation into the 2013 ACR/EULAR classification criteria. Clear prognostic and phenotypic associations with cutaneous subtype and internal organ involvement have been also described. However, little is known about the potential of autoantibodies to exert a direct pathogenic role in SSc. The aim of the study is to assess the pathogenic capacity of anti-DNA-topoisomerase I (anti-Topo-I) and anti-centromeric protein B (anti-Cenp-B) autoantibodies to induce pro-fibrotic markers in dermal fibroblasts.

METHODS

Dermal fibroblasts were isolated from unaffected and affected skin samples of (n = 10) limited cutaneous SSc (LcSSc) patients, from affected skin samples of diffuse cutaneous (DcSSc) patients (n = 10) and from healthy subjects (n = 20). Fibroblasts were stimulated with anti-Topo-I, anti-Cenp-B IgGs, and control IgGs in ratios 1:100 and 1:200 for 24 h. Cells were also incubated with 10% SSc anti-Topo-I+ and anti-Cenp-B+ whole serum and with 10% control serum for 24 h. Viability was assessed by MTT test, while apoptosis was assessed by flow cytometry. Activation of pro-fibrotic genes ACTA2, COL1A1, and TAGLN was evaluated by quantitative real-time PCR (qPCR), while the respective protein levels alpha-smooth-muscle actin (α-SMA), type-I-collagen (Col-I), and transgelin (SM22) were assessed by immunocytochemistry (ICC).

RESULTS

MTT showed that anti-Cenp-B/anti-Topo-I IgGs and anti-Cenp-B+/anti-Topo-I+ sera reduced viability (in a dilution-dependent manner for IgGs) for all the fibroblast populations. Apoptosis is induced in unaffected LcSSc and control fibroblasts, while affected LcSSc/DcSSc fibroblasts showed apoptosis resistance. Basal mRNA (ACTA2, COL1A1, and TAGLN) and protein (α-SMA, Col-1, and SM22) levels were higher in affected LcSSc/DcSSc fibroblasts compared to LcSSc unaffected and to control ones. Stimulation with anti-Cenp-B/anti-Topo-I IgGs and with anti-Cenp-B+/anti-Topo-I+ sera showed a better induction in unaffected LcSSc and control fibroblasts. However, a statistically significant increase of all pro-fibrotic markers is reported also in affected LcSSc/DcSSc fibroblasts upon stimulation with both IgGs and sera.

CONCLUSIONS

This study suggests a pathogenic role of SSc-specific autoantibodies to directly induce pro-fibrotic activation in human dermal fibroblasts. Therefore, besides the diagnostic and prognostic use of those autoantibodies, these data might further justify the importance of immunosuppressive drugs in the early stages of the autoimmune disease, including SSc.