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

A scoping review of the epidemiology of systemic sclerosis and its organ manifestations: 2018-2024

PURPOSE OF REVIEW

Updates from large, observational cohorts and new statistical techniques have resulted in new data on the epidemiology of systemic sclerosis (SSc). This scoping review uses data from 2018 to 2024 to describe the current understanding of the epidemiology of SSc and several of its organ- manifestations.

RECENT FINDINGS

Our review identified new estimates for the global incidence and prevalence of SSc (1.4-8.6 per 100 000 person-years and 17.6-18.9 per 100 000 individuals, respectively). Mortality rates remain high, though mortality at younger ages has decreased. interstitial lung disease and pulmonary arterial hypertension remain the most common causes of death for patients with SSc. Literature on gastrointestinal (GI) manifestations of SSc was scarce, and we identified significant heterogeneity in results. Furthermore, data on the epidemiology of racial, ethnic and sex-based disparities was lacking.

SUMMARY

New techniques for the evaluation of the epidemiology of SSc highlight the high morbidity and mortality of SSc, and a growing prevalence rate compared with prior eras. Further research is needed to address notable heterogeneity in the reporting of epidemiological data and understudied disease manifestations, including GI disease and health disparities in disease outcomes.

Could Gas6/TAM Axis Provide Valuable Insights into the Pathogenesis of Systemic Sclerosis?

Systemic sclerosis (SSc) is a connective tissue disorder characterized by microvascular injury, extracellular matrix deposition, autoimmunity, inflammation, and fibrosis. The clinical complexity and high heterogeneity of the disease make the discovery of potential therapeutic targets difficult. However, the recent progress in the comprehension of its pathogenesis is encouraging. Growth Arrest-Specific 6 (Gas6) and Tyro3, Axl, and MerTK (TAM) receptors are involved in multiple biological processes, including modulation of the immune response, phagocytosis, apoptosis, fibrosis, inflammation, cancer development, and autoimmune disorders. In the present manuscript, we review the current evidence regarding SSc pathogenesis and the role of the Gas6/TAM system in several human diseases, suggesting its likely contribution in SSc and highlighting areas where further research is necessary to fully comprehend the role of TAM receptors in this condition. Indeed, understanding the involvement of TAM receptors in SSc, which is currently unknown, could provide valuable insights for novel potential therapeutic targets.

Scleroderma: oral, maxillofacial and radiographic manifestations for dental practitioners

Scleroderma is an autoimmune condition of unknown aetiology with a range of manifestations, which can be limited to the skin or can extend to be multisystemic. It is characterised by fibrosis, microangiopathy and dysregulation of the immune system and commonly affects the oral cavity. Frequent oral and maxillofacial features include fibrosis of the face, circumoral furrows and reduced oral aperture. Radiographic findings are often incidental, including uniform, asymptomatic periodontal ligament space widening of teeth and osteolysis of bone at muscular attachments. The oral and maxillofacial manifestations significantly contribute to its disease burden and are often overlooked and undertreated as their treatment can be limited due to their challenging rheumatological care. Given the complexity of the condition and its multisystemic impacts, better co-operation between dentists and rheumatologists may help improve this patient cohort's quality of life. This clinical article aims to better equip dentists to identify features of scleroderma and manage the day-to-day oro-facial manifestations.

Journey into the Esophageal Complications: Decoding Systemic Sclerosis with Cutting-Edge Endoscopy, Manometry, and Ambulatory pH-Study

Purpose

Systemic Sclerosis (SSc) is a rare connective tissue disorder characterized by autoimmunity, fibrosis, and vasculopathy that affects the skin and internal organs, including the gastrointestinal tract, particularly the esophagus. This article highlights the characteristics and clinical symptoms of esophageal involvement in patients with SSc.

Patients and Methods

This study was conducted between November 2022 to August 2023, including 26 already diagnosed cases of SSc in the Department of Rheumatology and Rehabilitation and Kurdistan Center for Gastroenterology and Hepatology-Sulaymaniyah, Iraq. Esophageal involvement was investigated using esophageal manometry, esophagogastroduodenoscopy (EGD), and 24-hour impedance-pH monitoring.

Results

Females were significantly predominant (P = 0.019) regarding the symptoms; 76.9% of the patients had heart burn, 76.9% dysphagia, 73.1% water brush, and 69.2% regurgitation. In total, 69.2% of the patients showed erosive gastrointestinal reflux disease (GERD) on EGD, 76.9% had decreased lower esophageal sphincter pressure (DLESP) and decreased distal esophageal peristaltic contractions (DDEPC) on esophageal manometry, and 84.6% had reflux on pH monitoring. Raynaud's phenomenon is the most common and typically the earliest clinical manifestation of SSc. The presence of erosive GERD was found to significantly increase the risk of developing dysphagia (B = 4.725, P = 0.014, OR = 3.482) and regurgitation (B = 3.521, P = 0.006, OR = 4.030).

Conclusion

It is crucial to take gender-specific considerations into account when diagnosing and managing esophageal complications in patients with systemic sclerosis (SSc). Additionally, employing various diagnostic assessments to detect esophageal involvement during SSc is essential. Erosive GERD has been identified as a risk factor that contributes to the development of dysphagia and regurgitation in individuals with SSc.

Higher gamma-glutamyl transferase levels are associated with an increased risk of incident systemic sclerosis: a nationwide population-based study

Gamma-glutamyl transferase (GGT) is known to promote oxidative stress. As oxidative stress is a key component in the pathogenesis of systemic sclerosis (SSc), we investigated whether GGT levels are associated with the risk of incident SSc. A cohort of individuals without SSc who underwent national health examination in 2009 were extracted from the Korean National Health Insurance Service database. The incidence rate of SSc during the observation period, between 2009 and 2019, was estimated. GGT levels measured in 2009 were categorized into quartiles (Q1 [lowest], Q2, Q3, and Q4 [highest]). Multivariable Cox proportional hazard models were used to estimate the risk of incident SSc according to the quartiles of GGT, using Q1 as the reference. A total of 6,091,788 individuals were included. Incidence rate of SSc was 1.16 per 100,000 person-years over a mean observation period of 9.2 years. After adjusting for age, sex, body mass index, economic income, smoking status, alcohol consumption, physical activity, hypertension, type 2 diabetes, dyslipidemia, and chronic kidney disease, higher quartiles of GGT levels were significantly associated with a higher risk of incident SSc (Q4: adjusted hazard ratio [aHR] 1.807, 95% confidence interval CI 1.446-2.259; Q3: aHR 1.221, 95% CI 0.971-1.536; and Q2: aHR 1.034, 95% CI 0.807-1.324; p for trend < 0.001). Higher GGT levels were associated with a higher risk of incident SSc. These findings could lead to a closer monitoring for high risk individuals and an earlier diagnosis and treatment.

Association Between Lipid Profile and Risk of Incident Systemic Sclerosis: A Nationwide Population-Based Study

Background and Aims

Lipid metabolism is altered in systemic sclerosis (SSc), mediating activation of immune cells and fibroblasts. However, it is unclear whether altered lipid profile is associated with a risk of developing SSc. We aimed to assess the association between lipid profile and risk of incident SSc.

Methods

From a Korean nationwide database, individuals without SSc who underwent national health check-ups in 2009 were selected and followed-up through 2019. Serum levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride were measured on the health check-up date in 2009. Individuals who developed SSc during follow-up were identified. Multivariable Cox models were performed to estimate the risk of incident SSc according to TC, HDL-C, LDL-C, and triglyceride levels, respectively.

Results

Of the 9,894,996 individuals selected, 1355 individuals developed SSc during a mean follow-up of 9.2 years (incidence rate=1.49 per 100,000 person-years). Levels of TC (adjusted hazard ratio [aHR] 0.959, 95% confidence interval [CI] 0.945-0.974), HDL-C (aHR 0.968, 95% CI 0.950-0.987), LDL-C (aHR 0.968, 95% CI 0.952-0.983) were inversely associated with the risk of incident SSc, whereas no significant association was observed between levels of triglyceride (aHR 1.004, 95% CI 0.998-1.011) and risk of incident SSc.

Conclusion

Serum levels of TC, HDL-C, and LDL-C were inversely associated with the risk of incident SSc. Our findings provide new insights that altered lipid profile could be considered a non-causal biomarker associated with incident SSc, which could help early diagnosis. The underlying mechanism for this association needs further studies.

Risk of kidney failure in patients with systemic sclerosis: a nationwide population-based study

OBJECTIVE

Data from a decade ago have shown that patients with systemic sclerosis (SSc) have a higher risk of kidney failure than the general population. However, as the incidence of kidney failure due to SSc has been declining, the comparative risk of kidney failure between patients with SSc and the general population could have changed over time. We investigated the risk of kidney failure in patients with SSc compared with the general population, up to more recent years.

METHODS

This was a nationwide population-based study using the Korean National Health Insurance Service database. Patients with claims data for SSc between 2010 and 2017 (n=2591) and 1:5 age-matched and sex-matched controls (n=12 955) were selected. The index date was the earliest date of claim for SSc between 2010 and 2017. The follow-up duration was from the index date to 2019. The adjusted HRs (aHRs) and 95% CI for kidney failure were estimated using multivariable Cox proportional hazard models.

RESULTS

Over 5.2±2.6 years, the incidence rates of kidney failure in patients with SSc and controls were 2.88 and 0.35 per 1000 person-years, respectively. Patients with SSc had a significantly higher risk of kidney failure than controls (aHR=7.244, 95% CI=4.256 to 12.329). The effect size was larger in patients diagnosed with SSc between 2014 and 2017 (aHR=9.754, 95% CI=3.254 to 29.235) than in those diagnosed before 2010 (aHR=6.568, 95% CI=2.711 to 15.571) or between 2010 and 2013 (aHR=6.553, 95% CI=2.721 to 15.781).

CONCLUSION

The risk of kidney failure remains higher in patients with SSc than in the general population.

Maternal-fetal outcomes in patients with immune mediated inflammatory diseases, with consideration of comorbidities: a retrospective cohort study in a large U.S. healthcare system

Background

Immune-mediated inflammatory diseases (IMIDs) are likely to complicate maternal health. However, literature data on patients with IMIDs undergoing pregnancy is scarce and often overlooks the impact of comorbidities.

Methods

We investigated 12 selected IMIDs: psoriasis, inflammatory bowel disease, rheumatoid arthritis, spondyloarthritis, multiple sclerosis, systemic lupus erythematosus, psoriatic arthritis, antiphospholipid syndrome, Sjögren's syndrome, vasculitis, sarcoidosis, systemic sclerosis. We characterized patients with IMIDs prior to pregnancy (IMIDs group) based on pregnancy/maternal characteristics, comorbidities, and pre-pregnancy/prenatal immunomodulatory medications (IMMs) prescription patterns. We 1:1 propensity score matched the IMIDs cohort with people who had no IMID diagnoses prior to pregnancy (non-IMIDs cohort). Outcome measures were preterm birth (PTB), low birth weight (LBW), small for gestational age (SGA), and cesarean section.

Findings

The prevalence rate of pregnancy occurring with people with a previous IMID diagnosis has doubled in the past ten years. We identified 5,784 patients with IMIDs. 17% of the IMIDs group had at least one prenatal IMM prescription. Depending on the type of IMM, from 48% to 70% of the patients taking IMMs before pregnancy continued them throughout pregnancy. Patients with IMIDs had similar but slightly increased risks of PTB (Relative risk (RR)=1·1[1·0, 1·3]), LBW (RR=1·2 [1·0,1·4]), SGA (RR=1·1 [1·0,1·2]), and cesarean section (RR=1·1 [1·1,1·2]) compared to a matched cohort of people without IMIDs. Out of the 12 selected IMIDs, three for PTB, one for LBW, two for SGA, and six for cesarean section had results supporting increased risk.

Interpretation

The association between IMIDs and the increased risk of adverse pregnancy outcomes depend on both the nature of the IMID and the presence of comorbidities.

Environmental Risks for Systemic Sclerosis

There is an increasing body of literature suggesting a relationship between environmental factors and the development of systemic sclerosis (SSc). These include occupational exposures, chemical materials, medications, alterations in the microbiome, and dysbiosis. Environmental exposures may impact epigenetic regulation thereby triggering an aberrant immune response resulting in the clinical and serologic phenotype that we diagnose as SSc. Screening and studying putative triggers will not only improve our understanding of the pathogenesis of SSc but also inform the institution for protective measures.

Developmental trichloroethylene exposure enhances predictive markers of autoimmunity in a sex-specific manner in disease-resistant female mice

Trichloroethylene (TCE) is a widely used industrial chemical and common environmental pollutant. Exposure to TCE promotes CD4⁺ T cell-driven autoimmunity including autoimmune hepatitis (AIH) in both humans and female autoimmune-prone mice. Because the developing immune system is more sensitive during development, we predicted that non- autoimmune-prone, C57/Bl6 (B6) mice would exhibit some autoimmune-related changes using the Developmental Origins of Health and Disease (DOHaD) model of exposure. Both male and female mice were exposed to vehicle or an environmentally relevant dose of 5 μg/ml TCE (0.9 mg/kg/day) beginning at 2 weeks pre-conception and ending at weaning. CD4+ T cells were assessed for phenotypic markers by flow cytometry. An assessment of cytokines elicited ex vivo after 4d polarization from naïve to CD4⁺ T helper subsets (i.e., Th1, Th17, and T reg) was conducted. mRNA expression of liver genes associated with inflammation, regeneration/repair associated with AIH disease progression in autoimmune-prone mice were evaluated by qRT-PCR. The results demonstrated TCE's ability to induce autoimmune- related biomarkers in B6 mice to an even greater degree in females compared to males when exposed during development.

HIV-Associated Systemic Sclerosis: Literature Review and a Rare Case Report

Highly antiretroviral therapy (HAART) used in Human Immunodeficiency Virus (HIV) treatment may prolong the life span of people living with HIV/Acquired Immune Deficiency Syndrome (AIDS) but may also induce the onset of autoimmune disorders. However, HIV-associated systemic sclerosis (SSc) is an extremely rare occurrence, and only four case reports and two studies documenting this association have been reported to date. We report a rare case of HIV-associated SSc who was referred to us for pain management in her mandibular teeth. A 44-year-old female patient diagnosed with HIV-associated SSc reported a complaint of pain in the lower posterior teeth region. Physical examination revealed typical features of SSc. The pain in her mandibular teeth was due to food lodgement, and she was advised to use toothpaste with a powered toothbrush and mouth stretching exercises, followed by oral prophylaxis. The patient responded well to therapy. HIV-associated SSc is an extremely rare occurrence, with an obscure pathogenic mechanism of HIV-associated autoimmunity. Oral physicians play a crucial role in disease management and should be incorporated into the multidisciplinary team.

Juvenile systemic sclerosis - observations of one clinical centre

OBJECTIVES

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Etiological factors of systemic sclerosis in the southeast region of Romania

Systemic sclerosis (SSc) is a relatively rare autoimmune disease with skin and visceral involvement, having a yet unknown etiopathogenesis. Research has shown that professional exposure to various polluting chemicals such as dyes, aliphatic and aromatic organic solvents, inhalable silica dust or certain heavy metals, can be triggering factors for this disease when they overlap a predisposing genetic profile. Smoking is still a debated factor involved in the etiology of SSc, as authors have divergent opinions on this matter. The present study was designed to analyze the etiological factors identified in the group of 37 patients with diffuse and limited SSc from the southeast region of Romania and the results were compared to the literature data. In the group of patients included in this study, occupational exposure and smoking history were not present in all patients, and a hereditary factor was identified only in an isolated case. The majority of patients suffered from a major negative psychological event or from long-term stressful situations and these factors were associated with smoking history or occupational exposure; this suggests that SSc is initiated in a set of cumulative triggering factors.

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.

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.