Prevalence of systemic sclerosis in south-east Norway

Prevalence and gender - specific analysis of a systemic sclerosis cohort in Latvia

BACKGROUND

Systemic sclerosis (SSc) is considered by many to be one of the most severe autoimmune rheumatic diseases with lower prevalence observed in Northern Europe. No previous studies on the prevalence of SSc in Latvia have been conducted and the aim was to study the demographic and clinical data of patients with SSc in northeastern Europe country.

METHODS

This study was conducted in two main Latvian hospitals for adults and includes patients with SSc who were consulted between 2016 and 2021.

RESULTS

During the study period, 159 patients with SSc were consulted. The point prevalence on 1 January 2021 was 84.0 per million. Female to male ratio was 4.67:1, and highest gender ratio was observed in the age group 70-79-year (6.75:1). Antinuclear antibodies were present in 82.58% of patients, without gender difference. Centromere pattern was more frequently observed in females (40.19% vs. 19.04%), in contrast to speckled pattern (50.98% vs. 57.14%). At disease onset females tended to be younger (46.51 ± 13.52) than males (50.5 ± 16.64). Males had more diffuse cutaneous subtype, interstitial lung disease, pulmonary hypertension and esophageal dysmotility. More than half of patients received treatment with glucocorticoids at any point of the disease (68.31%), without gender difference.

CONCLUSIONS

Systemic sclerosis is less common in Latvia than in other countries and regions. Due to its location, the data from Latvia are consistent with a north-south gradient in Europe. Gender ratio differences persisted in older age groups as well. Antinuclear antibodies presence did not differ between genders, but in female's centromere pattern was much more likely to be present. Males had more severe disease course, but in both genders more than half of patients received treatment with GCs at any point of the disease.

Unraveling the immunometabolism puzzle: Deciphering systemic sclerosis pathogenesis

The article delves into the pathogenesis of systemic sclerosis (SSc) with an emphasis on immunometabolism dysfunctions. SSc is a complex autoimmune connective tissue disorder with skin and organ fibrosis manifestation, vasculopathy, and immune dysregulation. A growing amount of research indicates that immunometabolism plays a significant role in the pathogenesis of autoimmune diseases, including SSc. The review explores the intricate interplay between immune dysfunction and metabolic alterations, focusing on the metabolism of glucose, lipids, amino acids, the TCA (tricarboxylic acid) cycle, and oxidative stress in SSc disease. According to recent research, there are changes in various metabolic pathways that could trigger or perpetuate the SSc disease. Glycolysis and TCA pathways play a pivotal role in SSc pathogenesis through inducing fibrosis. Dysregulated fatty acid β-oxidation (FAO) and consequent lipid metabolism result in dysregulated extracellular matrix (ECM) breakdown and fibrosis induction. The altered metabolism of amino acids can significantly be involved in SSc pathogenesis through various mechanisms. Reactive oxygen species (ROS) production has a crucial role in tissue damage in SSc patients. Indeed, immunometabolism involvement in SSc is highlighted, which offers potential therapeutic avenues. The article underscores the need for comprehensive studies to unravel the multifaceted mechanisms driving SSc pathogenesis and progression.

Real-World Clinical Profile and Safety of Nintedanib in Systemic Sclerosis-Associated Interstitial Lung Disease: A Subgroup Analysis of Interstitial Lung Disease Data From an Interstitial Lung Disease (ILD) Specialty Clinic in India

INTRODUCTION

 Systemic sclerosis (SSc) is a multisystem autoimmune disorder characterized by dysregulated innate and adaptive immunity. Interstitial lung disease (ILD) is a common and serious complication of SSc, often leading to significant morbidity and mortality. Consistent demographic characteristics that aid in the early diagnosis of ILD in SSc are lacking. This study aims to identify clinical and demographic parameters associated with ILD in SSc patients and assess the safety and tolerability of nintedanib with other immunosuppressants.

MATERIALS AND METHODS

This study is a subgroup analysis of data from the ILD clinic at All India Institute of Medical Sciences Raipur, collected between January 2022 and January 2024. We assessed the clinical and demographic profiles, high-resolution computed tomography thorax patterns, autoantibody profiles, lung function, and treatments used in the patients.

RESULTS

We enrolled 57 patients with SSc-associated ILD. The mean age of the participants was 39.0 ± 11.1 years, with 53 (92.9%) being women. The mean body mass index was 20.4 ± 4.32 kg/m². Dyspnea was the most common symptom, followed by skin tightening and cough. Antinuclear antibody tests were positive in 92.9% of patients, and anti-Scl-70 antibodies were positive in 57.9%. Rheumatoid arthritis-SSc overlap was observed in 15.8% of patients. The mean predicted forced vital capacity was 46.5 ± 19.9%, the mean predicted total lung capacity was 64.5 ± 20.4%, and the mean predicted diffusing capacity for carbon monoxide was 46.2 ± 15.7%. The mean six-minute walk distance was 360.3 ± 81.2 meters, and the mean King's Brief Interstitial Lung Disease score was 63.9 ± 10.7. Common radiological abnormalities included ground-glass opacities in 57.8%, traction bronchiectasis in 43.8%, and honeycombing in 28.07%. The predominant ILD pattern was nonspecific interstitial pneumonia. Patients received a combination of prednisolone (5 mg/day) with mycophenolate mofetil (63.2%), hydroxychloroquine (17.5%), cyclophosphamide (12.3%), and methotrexate (7.02%). Nintedanib, the only antifibrotic used, was administered to 17 (29.8%) patients.

CONCLUSIONS

ILD is relatively common in SSc, particularly in patients with diffuse cutaneous SSc and those with anti-topoisomerase antibodies. Female patients comprised the predominant population in this study. Patients tolerated mycophenolate mofetil and cyclophosphamide well. Nintedanib was the only antifibrotic used, and all patients tolerated the combination of antifibrotics and immunosuppressants well. Early diagnosis is crucial to slow disease progression and preserve lung function. Our results highlight the need for vigilant screening in high-risk groups and suggest that MMF, cyclophosphamide, and nintedanib can be safely incorporated into treatment regimens, offering a potential strategy to improve patient outcomes.

Immersion Ultrasound Therapy in Combination with Manual Therapy in the Treatment of Ischemic Digital Ulcers in Systemic Sclerosis

Background and Objectives: Digital ulcers (DUs) are the most common complication in patients with Systemic Sclerosis (SSc). They cause pain with hand dysfunction and negatively impact activities of daily and working life. Our study aims to evaluate the efficacy of a combined treatment of manual therapy and ultrasound therapy in SSc patients with ischemic DU (IDU) compared to manual therapy alone. Materials and Methods: We conducted a before-and-after study (non-randomized study). We enrolled a consecutive series of IDU patients undergoing rehabilitation treatment and divided them into two groups: a treatment group consisting of patients undergoing a combination of manual therapy and US water immersion and a standard care group consisting of patients subjected to manual therapy alone. At the time of the first visit (T0) and at the end of the 4-week rehabilitation period (T1), we evaluated functional capacity, pain intensity, ulcer evolution, and quality of life. Results: In the treatment group, we observed a statistically significant improvement in the functional capacity of the hand (DHI: 28.15 ± 11.0 vs. 19.05 ± 8.83; p < 0.05), pain (NRS: 5.55 ± 1.2 vs. 2.9 ± 1.09; p < 0.05), and PSST score (24.4 ± 4.0 vs. 16.2 ± 2.36; p < 0.05). In the standard care group, we observed a statistically significant improvement only for the functional capacity of the hand (DHI: 28.85 ± 9.72 vs. 22.7 ± 7.68; p < 0.05). Finally, from the comparison between the treatment group and the standard care group, we observed statistically significant improvements in pain (2.9 ± 1.09 vs. 4.5 ± 1.07; p < 0.05) and in the PSST scale (16.2 ± 2.36 vs. 20.4 ± 4.02; p < 0.05). Furthermore, at the end of treatment in the treatment group, 15 ulcers (62.5%) were completely healed, while in the standard care group, only 3 ulcers were completely healed (14.3%). Conclusions: Combined treatment with manual therapy and ultrasound therapy appears to be useful in the management of IDU in patients with scleroderma.

Gastrointestinal symptom severity and progression in systemic sclerosis

OBJECTIVES

To evaluate the severity and evolution of patient-reported gastrointestinal tract (GIT) symptoms in systemic sclerosis (SSc) patients, assess predictive factors for progression and determine the impact of standard of care treatment.

METHODS

SSc patients from the Leiden and Oslo cohorts were included. We assessed clinical data and patient-reported GIT symptoms measured by the validated University of California, Los-Angeles Gastrointestinal-tract (UCLA-GIT) score at baseline and annually. GIT severity and progression was determined. Logistic regression was applied to identify risk factors associated with baseline GIT symptom severity. Linear mixed-effect models were applied to assess progression in GIT symptom burden and to identify predictive factors. We repeated all analysis in patients with early disease (inception cohort) to exclude the effect of longstanding disease and increase insights in development of GIT symptom burden early in the disease course.

RESULTS

We included 834 SSc patients with baseline UCLA GIT scores, 454 from Leiden and 380 from Oslo. In the total cohort, 28% reported moderate-severe GIT symptoms at baseline, with increased risk for severity conferred by ACA, smoking and corticosteroid use, while use of calcium channel blockers appeared protective. In the inception cohort, 23% reported moderate-severe GIT symptoms at baseline, with increased risk for females and with smoking. Over time, symptom burden increased mainly for reflux/bloating. Female sex and ACA predicted GIT symptom progression.

CONCLUSION

High GIT symptom burden is present early in SSc disease course. Both for prevalence and for progression of GIT symptom burden, female sex and smoking were identified as risk factors.

Incidence, prevalence and regional distribution of systemic sclerosis and related interstitial lung Disease: A nationwide retrospective cohort study

Objective

To investigate incidence and prevalence of Systemic Sclerosis (SSc) and association with interstitial lung disease (SSc-ILD) in a nationwide population-based study.

Methods

Patients with an incident diagnosis of SSc in 2000–2016 were identified in the Danish National Patient Registry and categorised based on diagnosis of ILD. Incidence- and prevalence proportions were calculated based on the annual population estimates. A cox proportional hazards model was used to evaluate the association between age, sex, region and marital status and presence of ILD.

Results

In total, 1869 patients with SSc were identified; 275 patients (14.7%) had SSc-ILD. The majority of patients were females (75.5%). The percentage of males was higher in SSc-ILD than in SSc alone (30.9% and 23.4%, p = 0.008). Median time from SSc to ILD diagnosis was 1.4 years (range 0–14.2). ILD was diagnosed from ≤4 years before to ≥7 years after SSc. Development of ILD was associated with male gender (HR 1.75, 95% CI 1.15–2.66), age 41–50 (HR 1.81, 95% CI 1.07–3.05) and residency in the North Denmark Region (HR 1.95, 9 5% CI 1.12–3.40). Mean annual incidence proportion of SSc was 2.9/100,000 and mean annual prevalence proportion was 16.8/100,000. The incidence remained stable, but prevalence proportion increased from 14.1 – 16.5/100,000 in 2000–2008 to 17.9–19.2/100,000 in 2009–2016.

Conclusion

The prevalence of SSc increased during the study period, while the incidence remained stable. The prevalence of SSc-ILD was 14.7% and thus less frequent than expected. Male sex and age between 41 and 50 years were associated with ILD.

Cerebral infarction caused by systemic sclerosis: a case report

Systemic sclerosis, also known as scleroderma, is a rare multisystem autoimmune disease characterized by vascular lesions caused by collagen deposition in the skin and viscera and damage to the endothelium. Endothelial injury and microvascular occlusion result in Raynaud's phenomenon, finger ischemia, pulmonary hypertension, and scleroderma renal crisis. Scleroderma itself is a rare disease with an incidence ranging from 0.1 to 14 per 100,000 people in the general population. Cerebral involvement is not considered a common manifestation of systemic sclerosis, although studies have shown that the brain can be involved. Therefore, to deepen the understanding of this disease, we herein report a case of cerebral infarction associated with systemic sclerosis.

Incidence and prevalence of systemic sclerosis globally: a comprehensive systematic review and meta-analysis

OBJECTIVES

We aimed to conduct a systematic review and meta-analysis on the incidence and prevalence of SSc covering the entire literature.

METHODS

This study followed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement of 2009. We conducted a systematic search in MEDLINE, Web of Science and Embase to identify articles reporting incidence and/or prevalence of SSc. Two authors conducted the search, reviewed articles for inclusion and extracted relevant data. We used random-effects models to estimate the pooled prevalence and incidence of SSc and performed subgroup analyses by sex, case definition and region to investigate heterogeneity. We explored the association between calendar period and reported estimates using meta-regression.

RESULTS

Among 6983 unique records identified, we included 61 studies of prevalence and 39 studies of incidence in the systematic review. The overall pooled prevalence of SSc was 17.6 (95% CI 15.1, 20.5) per 100 000 and the overall pooled incidence rate of SSc was 1.4 (95% CI 1.1, 1.9) per 100 000 person-years. We observed significant regional variations in reported estimates; studies conducted in North America reported considerably higher estimates than other regions. The pooled incidence and prevalence in women were five times higher than in men. More recent studies reported higher estimates than older ones.

CONCLUSION

In this comprehensive review of the incidence and prevalence of SSc across the world, there was large heterogeneity among estimates, which should be taken into consideration when interpreting the results.

Epidemiology of systemic sclerosis in the UK: an analysis of the Clinical Practice Research Datalink

OBJECTIVES

We developed and tested a robust case ascertainment strategy within the Clinical Practice Research Datalink (CPRD), with the aim of assessing the incidence, prevalence, mortality and delay in diagnosis of SSc in the UK.

METHODS

A two-stage case ascertainment strategy was devised and tested to establish a valid cohort of SSc cases within the CPRD. Incidence, prevalence and mortality statistics were analysed, alongside evaluation of the relationship between primary care codes for RP and SSc to examine diagnostic delay.

RESULTS

SSc Read codes were identified in 3123 patients (from a study cohort of >10.1 million individuals). Of these, 1757 cases of SSc were identified using our case ascertainment approach. The overall incidence rate of SSc over the period between 1999 and 2017 was 10.7/million/year (95% CI: 9.9-11.4), being higher in females [17.69/million/year (95% CI: 16.32-19.07)] than in males [3.59/million/year (95% CI: 2.97-4.21)]. The overall prevalence of SSc in adults was 235.5/million (95% CI: 207.2-245.7). The mean rate of mortality was 32/1000 person-years, with an overall standardized mortality ratio of 3.51 (95% CI: 3.19-3.84). Of those with an initial code of RP prior to a Read code of SSc, 191/854 (22.4%) had a lag period of >10 years.

CONCLUSION

We have developed and tested a robust case ascertainment strategy to examine the incidence, prevalence, mortality and diagnostic delay of SSc using primary care records of over 10 million UK residents. A significant lag between coding of RP and SSc in many patients suggests diagnostic delay in SSc remains an important unmet need.

Anti-centromere antibody levels and isotypes and the development of systemic sclerosis

Objective

Little is known on the disease course of very early systemic sclerosis (SSc). Among the information yet to be elucidated is whether anticentromere antibody (ACA) isotype levels can serve as biomarkers for future SSc development and for organ involvement. This study was undertaken to evaluate whether IgG, IgM, and IgA ACA levels in IgG ACA–positive patients are associated with disease severity and/or progression from very early SSc to definite SSc.

Methods

IgG ACA–positive patients from 5 different cohorts who had very early SSc or SSc fulfilling the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2013 criteria were included. A diagnosis of very early SSc was based on the presence of IgG ACAs and Raynaud’s phenomenon, and/or puffy fingers and/or abnormal nailfold capillaroscopy, but not fulfilling the ACR/EULAR 2013 criteria for SSc. Multivariable regression analyses were performed to determine the association between baseline ACA isotype levels and progression to definite SSc with organ involvement.

Results

Six hundred twenty‐five IgG ACA–positive patients were included, of whom 138 (22%) fulfilled the criteria for very early SSc and 487 (78%) had definite SSc. Levels of IgG ACAs (odds ratio 2.5 [95% confidence interval 1.8–3.7]) and IgM ACAs (odds ratio 1.8 [95% confidence interval 1.3–2.3]) were significantly higher in patients with definite SSc. Of 115 patients with very early SSc with follow‐up, progression to definite SSc occurred within 5 years in 48 (42%). Progression to definite SSc was associated with higher IgG ACA levels at baseline (odds ratio 4.3 [95% confidence interval 1.7–10.7]).

Conclusion

ACA isotype levels may serve as biomarkers to identify patients with very early SSc who are at risk for disease progression to definite SSc.

Systemic Sclerosis and Associated Interstitial Lung Disease in Ontario, Canada: An Examination of Prevalence and Survival Over 10 Years

OBJECTIVE

Systemic sclerosis (SSc) is a rare autoimmune disease. Pulmonary complications of SSc are some of the leading causes of morbidity and mortality. The objective of this study was to determine prevalence and survival estimates of SSc and SSc with interstitial lung disease (SSc-ILD) in the Canadian province of Ontario using administrative data over 10 years.

METHODS

Using International Classification of Diseases, 10th revision codes adapted for Canada (ICD-10-CA), adult patients diagnosed with SSc and SSc-ILD between April 1, 2008, and March 31, 2018, were identified from the National Ambulatory Care Reporting System and the Discharge Abstract Database administrative databases. SSc was identified first, and ILD was included if presence occurred after SSc diagnosis. Prevalence estimates were determined for both SSc and SSc-ILD. For survival rates, Kaplan-Meier survival curves were generated.

RESULTS

At the start of the 2017/18 fiscal year (final year of the cohort), there were 2114 prevalent SSc cases for a cumulative prevalence of 19.1 per 100,000 persons, as well as 257 prevalent cases of SSc-ILD that generated a prevalence of 2.3 cases per 100,000 persons. Mean ages were 57 and 58 years with 84% and 80% females for patients with SSc and SSc-ILD, respectively. One-, 5-, and 10-year survival rates were 85.0%, 64.5%, and 44.9% for the SSc group and 77.1%, 44.4%, and 22.0% for the SSc-ILD group, respectively.

CONCLUSION

To our knowledge, this study provides the first population-based estimates of SSc and SSc-ILD in Canada for prevalence and survival. Results confirm that the prevalence estimates of SSc-ILD fall within the Canadian threshold for rare disease. It also demonstrates the poor survival in SSc, especially when ILD is also present.

Economic Burden and Management of Systemic Sclerosis-Associated Interstitial Lung Disease in 8 European Countries: The BUILDup Delphi Consensus Study

INTRODUCTION

Systemic sclerosis (SSc) is a rare chronic autoimmune disease characterised by microvascular damage, immune dysregulation and fibrosis, affecting the skin, joints and internal organs. Interstitial lung disease (ILD) is frequently associated with systemic sclerosis (SSc-ILD), leading to a poor prognosis and a high mortality rate. The aim of the BUILDup study (BUrden of Interstitial Lung Disease Consensus Panel) was to investigate the overall disease management and to estimate the social and economic burden of SSc-ILD across 8 European countries.

METHODS

A modified Delphi method was used to obtain information on the management of SSc-ILD patients among 40 specialists (panellists) from 8 European countries. Average annual costs per patient and country were estimated by means of a direct cost-analysis study.

RESULTS

The panellists had managed 805 SSc-ILD patients in the last year, 39.1% with limited (L-SSc-ILD) and 60.9% with extensive (E-SSc-ILD) disease. Of these, 32.8% of the panellists started treatment at diagnosis, 42.3% after signs of deterioration/progression and 24.7% when the disease had become extensive. The average annual cost of SSc-ILD per patient ranged from €6191 in Greece to €25,354 in Sweden. Main cost drivers were follow-up procedures, accounting for 80% of the total annual costs. Hospitalisations were the most important cost driver of follow-up costs. Healthcare resource use was more important for E-SSc-ILD compared to L-SSc-ILD. Early retirement was taken by 40.4% of the patients with an average of 11.9 years before the statutory retirement age.

CONCLUSIONS

SSc-ILD entails not only a clinical but also a social and economic burden, and is higher for E-SSc-ILD.

Emerging drugs for the treatment of scleroderma: a review of recent phase 2 and 3 trials

INTRODUCTION

Systemic sclerosis (SSc) has the highest case-specific mortality of all connective tissue diseases. Its underlying disease mechanism affects several organs and remains incompletely understood. Ongoing work clarifying its etiopathogenesis is helping to develop targeted therapy.

AREAS COVERED

Several clinical trials have evaluated the safety and efficacy of agents targeting different mechanisms of this disease. This review article reviews those mechanisms and surveys four key recent phase II or III clinical trials that are contributing to the landscape of SSc therapy. The reported trials primarily focus on patients with systemic sclerosis in the early phase of disease.

EXPERT OPINION

Traditional therapies for SSc center on immunosuppressive and cytotoxic agents. A new cadre of therapies is borne from improved understandings of SSc pathobiology and target the inflammatory-fibrotic pathways. Scleroderma trials have entered the initial phase of personalized medicine, recognizing molecular subsets that will improve upon cohort enrichment and maximize the measurable benefit of future therapies.

Epidemiological profile of systemic sclerosis in the southeast region of Romania

Systemic sclerosis (SSc) is a collagenosis, in which the microvasculature of the skin and internal organs becomes affected, followed by excessive deposition of connective tissue. It has been included in the group of rare diseases, and it seems to have had an increasing incidence over the last two decades. Statistics show, not only an increase in the incidence of SSc, but that of autoimmune diseases as a whole. The present study aimed to outline the epidemiological profile of SSc in the southeast region of Romania and to identify similarities and differences concerning the epidemiology of this disease in other countries. The current observational study was carried out on a group of 22 patients who were diagnosed with SSc and who were hospitalized at a university clinic in Bucharest. Our research revealed a higher prevalence of women suffering from SSc, with higher numbers suffering from the diffuse subset of this disease. In addition, we found that the majority of patients came from urban areas. SSc has an important impact on the quality of life of patients, thus opening the opportunity for studies to be carried out on larger populations of patients in order to identify epidemiological similarities and differences in various countries, as well as finding new experimental models useful for future research.

Incidence, prevalence and mortality of systemic sclerosis in Italy: a nationwide population-based study using administrative health data

To study incidence, prevalence and mortality of systemic sclerosis (SSc) in Italy, assessing epidemiological differences between men and women and in distinct age groups. We performed a nationwide population-based study using administrative health data from regional co-payment exemption registries. Patients entitled with SSc-specific co-payment exemption were included. Fourteen of the 20 Italian regions contributed data covering a population of over 45 million individuals. Crude annual incidence rate, annual prevalence, crude annual mortality rate and standardised mortality ratio (SMR) were calculated. In 2016, the overall crude incidence rate of SSc was 18.5 (95% CI 16.9-20.2) per million per year. Incidence rate was 31.0 (95% CI 28.1-34.1) per million in women, and 4.3 (95% CI 3.2-5.6) per million in men. Peak incidence was observed in the age range 55-69 years. Overall annual prevalence was 306.1 (95% CI 301.1-311.2) per million. Prevalence was 530.8 (95% CI 521.5-540.2) per million in women and 67.8 (95% CI 64.4-71.3) per million in men, with a female to male ratio of 7.8:1. Highest prevalence was observed in the range 70-84 years. Crude annual mortality rate was 27.9 (95% CI 24.9-31.1) per 1000 patients. Overall SMR in patients with SSc was 2.8 (95% CI 1.9-3.8). SMR was 3.8 (95% CI 2.9-5.1) in men and 2.6 (95% CI 1.8-3.6) in women. We provided updated estimates on epidemiology of SSc in Italy. Our findings on incidence, prevalence and mortality of SSc are consistent with previously published literature.

Multidimensional tracking of phenotypes and organ involvement in a complete nationwide systemic sclerosis cohort

OBJECTIVE

SSc is a severe, heterogeneous multi-organ disease where population-based estimates on phenotypic spectrum, overall disease burden and societal impact are largely missing. Here the objective was to provide the first-ever complete national-level data on phenotype and major organ afflictions in SSc.

METHODS

A stepwise strategy was applied to find and characterize every SSc patient resident in Norway from 2000 to 2012. First we identified every case in the country registered with an International Classification of Diseases, Tenth Revision code for SSc (M34). Next we manually reviewed all cases coded as M34 to determine whether they met the 1980 ACR and/or 2013 ACR/EULAR classification criteria for SSc and could be included in the Norwegian SSc cohort (Nor-SSc). Finally, all disease features from SSc onset to study end were reviewed.

RESULTS

The Nor-SSc cohort included 815 SSc patients. The mean age at diagnosis was 53 years, with 84% females and 77% limited cutaneous SSc. The estimated incidence increased from 4 per million in 2000 to 13 per million in 2012. We identified high cumulative frequencies of internal organ involvement, coexistence of multiple organ afflictions across disease subsets and autoantibody status and stable frequencies of pulmonary arterial hypertension across haemodynamic definitions, but indications of referral-related differences in pulmonary hypertension detection rates across the study area.

CONCLUSION

This nationwide cohort study provides new, unbiased evidence for a high disease burden in SSc patients of Caucasian descent and indicates the existence of hurdles preventing equality of assessment across the SSc population.

Association of Anti-Topoisomerase I Antibodies of the IgM Isotype With Disease Progression in Anti-Topoisomerase I-Positive Systemic Sclerosis

Objective

Anti–topoisomerase I (anti–topo I) autoantibodies in systemic sclerosis (SSc) are associated with diffuse skin involvement and interstitial lung fibrosis. Thus far, however, the relationship between anti–topo I antibody response and disease course has not yet been fully evaluated. This study was undertaken to gain insight into the association between characteristics of the anti–topo I antibody response and clinical disease course in SSc patients positive for anti–topo I antibodies.

Methods

Levels of anti–topo I IgG, anti–topo I IgM, and anti–topo I IgA were assessed in consecutive serum samples obtained from patients at baseline who were positive for anti–topo I IgG in the Leiden Combined Care In Systemic Sclerosis (CCISS) cohort. One‐year disease progression was defined by a relevant increase in modified Rodnan skin thickness score (MRSS), decline in pulmonary function, development of digital ulcers, renal crisis, and pulmonary hypertension, and/or mortality. Validation was performed in SSc patients who were positive for anti–topo I from the Oslo University Hospital and University Hospital Zurich.

Results

Of the 103 patients with anti–topo I IgG in the CCISS cohort, clinical data were available to assess 1‐year disease progression in 81 patients. Of these 81 patients, 23 (28%) had disease progression. At baseline, patients with disease progression were significantly more often anti–topo I IgM–positive than those who did not experience disease progression (21 [91%] of 23 versus 33 [57%] of 58; P < 0.01). This finding was confirmed in the independent validation samples.

Conclusion

In SSc patients who were anti–topo I IgG–positive, presence of anti–topo I IgM, which might be considered as a surrogate for an ongoing autoreactive B cell immune response, is associated with disease progression.

Characterizing Disease Manifestations and Treatment Patterns Among Adults with Systemic Sclerosis: A Retrospective Analysis of a US Healthcare Claims Population

INTRODUCTION

Real-world use of immunomodulating therapy (IMT) in patients with systemic sclerosis (SSc) was investigated for the first time in a descriptive, retrospective cohort analysis of claims made in a healthcare insurance database to characterize treatment patterns and their alignment with SSc disease manifestations.

METHODS

Treatment patterns and disease manifestations, symptoms, complications, and comorbidities were assessed in patients with SSc enrolled in a US healthcare claims database who received treatment between January 2006 and December 2013 and for whom data were available 6 months before and 12 months after SSc diagnosis.

RESULTS

Among 7812 eligible patients, 6852 received treatments of interest for SSc and 2404 (30.8%) received IMT during the first year after SSc diagnosis. In the first year after diagnosis, the most common claims were for antibiotics (61.7%), opioids (50.6%), glucocorticoids (46.5%), and proton pump inhibitors (35.4%); the most common organs involved with complications among patients with SSc were lung (30.5%), heart (17.4%), and gastrointestinal tract (22.4%); the most common signs or symptoms were musculoskeletal (16.1%) and fatigue (10.5%); 1035 patients (15.1%) had infections and 14 (0.2%) had malignancies. Among patients who received IMT, 43.8% received at least hydroxychloroquine and 21.1% received at least methotrexate; 460 patients switched to a second IMT, 23.0% to at least methotrexate and 22.8% to at least mycophenolate mofetil. The most common comorbidities reported with first IMT were in lung (11.8%), overlap syndrome (8.4%), heart (5.3%), and gastrointestinal (6.8%) categories.

CONCLUSION

One-third of patients with SSc in the healthcare claims population received IMTs during the first year after diagnosis. However, patients who received IMTs had disease manifestations similar to those of the overall SSc healthcare claims population.

Epidemiology of systemic sclerosis and systemic sclerosis-associated interstitial lung disease

Background: Interstitial lung disease (ILD) is one of the leading causes of mortality in patients with systemic sclerosis (SSc). To further understand this patient population, we present the first systematic review on the epidemiology of SSc and SSc-associated ILD (SSc-ILD).

Methods: Bibliographic databases and web sources were searched for studies including patients with SSc and SSc-ILD in Europe and North America (United States and Canada). The systematic review was limited to publications in English, German, French, Spanish, Italian, and Portuguese, published between January 1, 2000 and February 29, 2016. For all publications included in the review, the methodologic quality was assessed. For each dimension and region, data availability in terms of quantity and consistency of reported findings was evaluated.

Results: Fifty publications reporting epidemiologic data (prevalence, incidence, demographic profile, and survival and mortality) were included; 39 included patients with SSc and 16 included patients with SSc-ILD. The reported prevalence of SSc was 7.2–33.9 and 13.5–44.3 per 100,000 individuals in Europe and North America, respectively. Annual incidence estimates were 0.6–2.3 and 1.4–5.6 per 100,000 individuals in Europe and North America, respectively. Associated ILD was present in ~35% of the patients in Europe and ~52% of the patients in North America. In Europe, a study estimated the prevalence and annual incidence of SSc-ILD at 1.7–4.2 and 0.1–0.4 per 100,000 individuals, respectively. In both Europe and North America, SSc-ILD was diagnosed at a slightly older age than SSc, with both presentations of the disease affecting 2–3 times more women than men. Ten-year survival in patients with SSc was reported at 65–73% in Europe and 54–82% in North America, with cardiorespiratory manifestations (including ILD) associated with poor prognosis.

Conclusion: This systematic review confirms that SSc and SSc-ILD are rare, with geographic variation in prevalence and incidence.

Trends in incidence, mortality, and causes of death associated with systemic sclerosis in Denmark between 1995 and 2015: a nationwide cohort study

Background

To investigate the incidence and the mortality-rates of systemic sclerosis (SSc), its primary causes of death, and the temporal trends in events in Denmark during the last decades.

Methods

Using the Danish National Patient Registry, we identified all persons aged ≥18 years with a first-time diagnosis of SSc (ICD-10 code M34, excluding M34.2) between 1995 and 2015.

Results

A total of 2778 incident SSc cases were identified. The mean age at time of SSc diagnosis was 56 (standard deviation 15) years and 76% were women. The overall incidence rate (per 1,000,000 person-years) of diagnosed SSc was 24.4 (95% confidence interval 23.6–25.4), with a slight increase over the study period, age- and sex-adjusted incidence rate ratio 1.02 (95% confidence interval 1.01–1.02) per 1-year increase. The 1-year all-cause mortality rate per 100 person-years decreased from 6.1 (3.1–12.2) in 1995 to 5.3 (2.5–11.1) in 2015, sex- and age-adjusted hazard ratio 0.96 (95% CI 0.94–0.98) per 1-year increase. Over the period, the average age at SSc diagnosis increased and the proportion of women decreased, whereas the burden of comorbidities increased. One fifth of all deaths were attributable to cardiovascular causes, a fourth to pulmonary diseases, and 15% were due to cancer.

Conclusions

Within the last few decades, the incidence of SSc has increased and the 1-year mortality rate has decreased slightly in Denmark. Almost half of all deaths were attributable to cardiopulmonary causes.

Electronic supplementary material

The online version of this article (10.1186/s41927-018-0043-6) contains supplementary material, which is available to authorized users.

CCL21 as a Potential Serum Biomarker for Pulmonary Arterial Hypertension in Systemic Sclerosis

OBJECTIVE

Systemic sclerosis (SSc) is a major cause of pulmonary arterial hypertension (PAH). Murine models indicate key roles for chemokines CCL19 and CCL21 and their receptor CCR7 in lung inflammation leading to PAH. The objective of this study was to assess the chemokine CCL19-CCL21 axis in patients with SSc-related PAH.

METHODS

Serum samples obtained from 2 independent prospective SSc cohorts (n = 326), patients with idiopathic PAH (n = 12), and healthy control subjects (n = 100) were analyzed for CCL19/CCL21 levels, by enzyme-linked immunosorbent assay. The levels were defined as either high or low, using the mean + 2 SD value in controls as the cutoff value. Risk stratification at the time of PAH diagnosis and PAH-related events were performed. Descriptive and Cox regression analyses were conducted.

RESULTS

CCL21 levels were higher in patients with SSc compared with controls and were elevated prior to the diagnosis of PAH. PAH was more frequent in patients with high CCL21 levels (≥0.4 ng/ml) than in those with low CCL21 levels (33.3% versus 5.3% [P < 0.001]). In multivariate analyses, CCL21 was associated with PAH (hazard ratio [HR] 5.1, 95% CI 2.39-10.76 [P < 0.001]) and occurrence of PAH-related events (HR 4.7, 95% CI 2.12-10.46, P < 0.001). Risk stratification at the time of PAH diagnosis alone did not predict PAH-related events. However, when risk at diagnosis was combined with high or low CCL21 level, there was a significant predictive effect (HR 1.3, 95% CI 1.03-1.60 [P = 0.027]). A high CCL21 level was associated with decreased survival (P < 0.001).

CONCLUSION

CCL21 appears to be a promising marker for predicting the risk of SSc-related PAH and PAH progression. CCL21 may be part of a dysregulated immune pathway linked to the development of lung vascular damage in SSc.

The incidence, prevalence, and survival of systemic sclerosis in the UK Clinical Practice Research Datalink

To estimate the incidence, prevalence, and survival of systemic sclerosis in the United Kingdom. We conducted a historical cohort study using data from the Clinical Practice Research Datalink (CPRD). We calculated the incidence and survival of systemic sclerosis between 1994 and 2013 and examined its association with age, sex, and socioeconomic status. We calculated point prevalence on 1 July 2013 and examined its association with the same exposures. We identified 1327 cases with incident systemic sclerosis. Annual incidence was 19.4 per million person-years between 1994 and 2013. The incidence was 4.7 times higher in women than in men, was not influenced by socioeconomic status, and has remained stable over the 20 year study period. The peak age of onset was 55-69 years. Survival at 1, 5, and 10 years was 94.2, 80.0, and 65.7%, respectively. The prevalence was 307 (290-323) per million with the highest prevalence in the 70-84 years age group. We estimate there are currently 1180 new cases of systemic sclerosis each year in the UK, and 19,390 people living with systemic sclerosis. Due to the predicted growth and aging of the population, we predict a 24% increase in incident cases and 26% increase in prevalent cases in 20 years' time. Our estimates of incidence and prevalence are higher than previously reported in the UK, but similar to recent USA and Swedish studies, and do not support a north-south gradient of the occurrence of systemic sclerosis in Europe.

The Importance of Sex Stratification in Autoimmune Disease Biomarker Research: A Systematic Review

The immune system is highly dynamic and regulated by many baseline characteristic factors. As such, significant variability may exist among different patient groups suffering from the same autoimmune disease (AD). However, contemporary research practices tend to take the reductionist aggregate approach: they do not segment AD patients before embarking on biomarker discovery. This approach has been productive: many novel AD biomarkers have recently been discovered. Yet, subsequent validation studies of these biomarkers tend to suffer from a lack of specificity, sensitivity, and reproducibility which hamper their translation for clinical use. To enhance reproducibility in validation studies, an optimal discovery-phase study design is paramount: one which takes into account different parameters affecting the immune system biology. In this systematic review, we highlight need for stratification in one such parameter, i.e., sex stratification. We will first explore sex differences in immune system biology and AD prevalence, followed by reported sex-bias in the clinical phenotypes of two ADs—one which more commonly affects females: systemic lupus erythematosus, and one which more commonly affects males: ankylosing spondylitis. The practice of sex stratification in biomarker research may not only advance the discovery of sex-specific AD biomarkers but more importantly, promote reproducibility in subsequent validation studies, thus easing the translation of these novel biomarkers from bench to bedside to improve AD diagnosis. In addition, such practice will also promote deeper understanding for differential AD pathophysiology in males and females, which will be useful for the development of more effective interventions for each sex type.

Cardiopulmonary Disease Development in Anti-RNA Polymerase III-positive Systemic Sclerosis: Comparative Analyses from an Unselected, Prospective Patient Cohort

OBJECTIVE

Extensive skin disease and renal crisis are hallmarks of anti-RNA polymerase III (RNAP)-positive systemic sclerosis (SSc), while lung and heart involvement data are conflicting. Here, the aims were to perform time-course analyses of interstitial lung disease (ILD) and pulmonary hypertension (PH) in the RNAP subset of a prospective unselected SSc cohort and to use the other autoantibody subsets as comparators.

METHODS

The study cohort included 279 patients with SSc from the observational Oslo University Hospital cohort with complete data on (1) SSc-related autoantibodies, (2) paired, serial analyses of lung function and fibrosis by computed tomography, and (3) PH verified by right heart catheterization.

RESULTS

RNAP was positive in 33 patients (12%), 79% of which had diffuse cutaneous SSc. Pulmonary findings were heterogeneous; 49% had no signs of fibrosis while 18% had > 20% fibrosis at followup. Forced vital capacity at followup was < 80% in 39% of the RNAP subset, comparable to the antitopoisomerase subset (ATA; 47%), but higher than anticentromere (ACA; 13%). Accumulated frequency of PH in the RNAP subset (12%) was lower than in ACA (18%). At 93% and 78%, the 5- and 10-year survival rates in RNAP were comparable to the ATA and ACA subsets.

CONCLUSION

In this cohort, the RNAP subset was marked by cardiopulmonary heterogeneity, ranging from mild ILD to development of severe ILD in 18%, and PH development in 12%. These data indicate that cardiopulmonary risk stratification early in the disease course is particularly important in RNAP-positive SSc.

High Level of Chemokine CCL18 Is Associated With Pulmonary Function Deterioration, Lung Fibrosis Progression, and Reduced Survival in Systemic Sclerosis

OBJECTIVE

Markers for early identification of progressive interstitial lung disease (ILD) in systemic sclerosis (SSc) are in demand. Chemokine CCL18, which has been linked to pulmonary inflammation, is an interesting candidate, but data have not been consistent. We aimed to assess CCL18 levels in a large, prospective, unselected SSc cohort with longitudinal, paired data sets on pulmonary function and lung fibrosis.

METHODS

Sera from the Oslo University Hospital SSc cohort (n = 298) and healthy control subjects (n = 100) were analyzed for CCL18 by enzyme immunoassay. High CCL18 (>53 ng/mL) was defined using the mean value plus 2 SD in sera obtained from healthy control subjects as the cutoff.

RESULTS

High serum CCL18 was identified in 35% (105 of 298). Annual decline in FVC differed significantly between high and low CCL18 subsets (13.3% and 4.7%; P = .016), as did the annual progression rate of lung fibrosis (0.9% [SD, 2.9] and 0.2% [SD, 1.9]). Highest rates of annual FVC decline > 10% (21%) and annual fibrosis progression (1.2%) were seen in patients with high CCL18 and early disease (< 3 years). In multivariate analyses, CCL18 was associated with annual FVC decline > 10% (OR, 1.1; 95% CI, 1.01-1.11) and FVC < 70% at follow-up (OR, 3.1; 95% CI, 1.08-8.83). Survival analyses showed that patients with high CCL18 had reduced 5- and 10-year cumulative survival compared with patients with low CCL18 (85% and 74%, compared with 97% and 89%, respectively; P = .001).

CONCLUSIONS

The results from this prospective cohort reinforce the notion that high CCL18 may serve as a marker for early identification of progressive ILD in SSc.

Associations between circulating endostatin levels and vascular organ damage in systemic sclerosis and mixed connective tissue disease: an observational study

Introduction

Systemic sclerosis (SSc) and mixed connective tissue disease (MCTD) are chronic immune-mediated disorders complicated by vascular organ damage. The aim of this study was to examine the serum levels of the markers of neoangiogenesis: endostatin and vascular endothelial growth factor (VEGF), in our unselected cohorts of SSc and MCTD.

Methods

Sera of SSc patients (N = 298) and MCTD patients (N = 162) from two longitudinal Norwegian cohorts were included. Blood donors were included as controls (N = 100). Circulating VEGF and endostatin were analyzed by enzyme immunoassay.

Results

Mean endostatin levels were increased in SSc patients 93.7 (37) ng/ml (P < .001) and MCTD patients 83.2 (25) ng/ml (P < .001) compared to controls 65.1 (12) ng/ml. Median VEGF levels were elevated in SSc patients 209.0 (202) pg/ml compared to MCTD patients 181.3 (175) pg/ml (P = .017) and controls 150.0 (145) pg/ml (P < .001). Multivariable analysis of SSc subsets showed that pulmonary arterial hypertension (coefficient 15.7, 95 % CI: 2.2–29.2, P = .023) and scleroderma renal crisis (coefficient 77.6, 95 % CI: 59.3–100.0, P < .001) were associated with elevated endostatin levels. Multivariable analyses of MCTD subsets showed that digital ulcers were associated with elevated endostatin levels (coefficient 10.5, 95 % CI: 3.2–17.8, P = .005). The risk of death increased by 1.6 per SD endostatin increase (95 % CI: 1.2–2.1, P = .001) in the SSc cohort and by 1.6 per SD endostatin increase (95 % CI: 1.0–2.4, P = .041) in the MCTD cohort after adjustments to known risk factors.

Conclusions

Endostatin levels were elevated in patients with SSc and MCTD, particularly SSc patients with pulmonary arterial hypertension and scleroderma renal crisis, and MCTD patients with digital ulcers. Elevated endostatin levels were also associated with increased all-cause mortality during follow-up in both groups of patients. We propose that endostatin might indicate the degree of vascular injury in SSc and MCTD patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0756-5) contains supplementary material, which is available to authorized users.

Performance of the 2013 American College of Rheumatology/European League Against Rheumatism Classification Criteria for Systemic Sclerosis (SSc) in large, well-defined cohorts of SSc and mixed connective tissue disease

OBJECTIVE

To assess the 2013 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Classification Criteria for Systemic Sclerosis (SSc) on defined subgroups of SSc and in mixed connective tissue disease (MCTD) as an SSc-related disease.

METHODS

The 2013 ACR/EULAR criteria were assessed in 425 consecutive patients suspected to have SSc and seen at Oslo University Hospital, and in the nationwide Norwegian MCTD cohort (n = 178). In the SSc group, 239/425 patients had disease duration < 3 years (in 82 of these, duration was < 1 yr). Patients were subgrouped as limited SSc (n = 294), diffuse SSc (n = 97), SSc sine scleroderma (n = 10), and early SSc (prescleroderma; n = 24). Item data were complete, except nailfold capillaroscopy and telangiectasia results, missing in the MCTD cohort.

RESULTS

The 2013 ACR/EULAR SSc criteria were met by 409/425 patients (96%) in the SSc group. For comparison, only 75% (293/391) met the 1980 ACR SSc classification criteria. All the novel items in the 2013 ACR/EULAR criteria were frequent in the SSc cohort. Considering that there were missing data on 2 items, 10% (18/178) of the MCTD cohort met the 2013 ACR/EULAR criteria, giving an estimated specificity of 90% toward this SSc-like disorder.

CONCLUSION

In our large and representative group of consecutive patients with SSc, the 2013 ACR/EULAR SSc criteria were more sensitive than the ACR 1980 criteria. However, the new criteria did not completely segregate SSc from MCTD, making specificity a potential issue.

Prevalence and incidence of systemic sclerosis in southern Sweden: population-based data with case ascertainment using the 1980 ARA criteria and the proposed ACR-EULAR classification criteria

OBJECTIVES

To estimate the prevalence and incidence of systemic sclerosis (SSc) in southern Sweden.

METHODS

In Skåne, the southernmost region of Sweden (total population 1.2 million), healthcare provided is registered in the Skåne Healthcare Register. We identified all Skåne residents who had received an International Classification of Diseases 10 diagnosis of SSc (M34) or Raynaud's phenomenon (I73.0) between 1998 and 2010. Every single case was ascertained by review of medical records in reference to the 1980 American Rheumatism Association preliminary classification criteria for SSc and the proposed American College of Rheumatology (ACR)-European League Against Rheumatism (EULAR) classification criteria presented at the ACR/Association of Rheumatology Health Professionals Annual Meeting 2012. We calculated the point prevalence by the end of 2010 by linkage with the population register to exclude deceased persons and we also estimated the mean annual cumulative incidence for 2006-2010.

RESULTS

Using the 1980 ARA criteria, the adult prevalence and annual incidence of SSc in the Skåne region were 235 and 14 per 1 million inhabitants respectively. Applying the proposed ACR-EULAR criteria, the corresponding figures were 305 and 19 per 1 million inhabitants. A majority (82%) of the prevalent cases had the limited cutaneous SSc subtype.

CONCLUSIONS

The prevalence and incidence of SSc in southern Sweden, based on the 1980 ARA criteria, are higher than previously reported in northern Europe and do not support the concept of a north-south gradient of SSc occurrence in Europe. Application of the proposed ACR-EULAR classification criteria in this population results in about 30-40% higher estimates of SSc prevalence and incidence compared to the 1980 ARA criteria.

Survival and causes of death in an unselected and complete cohort of Norwegian patients with systemic sclerosis

OBJECTIVE

To determine survival and causes of death in an unselected and complete cohort of Norwegian patients with systemic sclerosis (SSc) compared to the background population.

METHODS

Multiple methods were used to identify every patient with SSc living in southeast Norway, with a denominator population of 2,707,012, between 1999 and 2009. All patients who met either the American College of Rheumatology criteria or the Medsger and LeRoy criteria for SSc were included. Every patient was matched for sex and age with 15 healthy controls drawn from the national population registry. Vital status at January 1, 2010, was provided for patients and controls by the national population registry. Causes of death were obtained from death certificates and by chart review.

RESULTS

Forty-three (14%) of 312 patients with SSc died during the study period. The standardized mortality rate (SMR) was estimated to be 2.03 for the entire cohort and 5.33 for the subgroup with diffuse cutaneous (dc) SSc. The 5- and 10-year survival rates were 91% and 70%, respectively, for dcSSc and 98% and 93% for limited cutaneous (lc) SSc. Causes of death were related to SSc in 24/43 (56%) patients, mostly cardiopulmonary diseases (n = 13), including pulmonary hypertension (n = 8). Factors associated with fatal outcome included male sex, dcSSc, pulmonary hypertension, and interstitial lung disease.

CONCLUSION

Compared to the Norwegian background population, our cohort of 312 unselected patients with SSc had decreased survival. The survival rates observed were, however, better than those previously reported from SSc referral centers.