Interpretation of an Extended Autoantibody Profile in a Well-Characterized Australian Systemic Sclerosis (Scleroderma) Cohort Using Principal Components Analysis

The nosology of systemic sclerosis: how lessons from the past offer new challenges in reframing an idiopathic rheumatological disorder

Systemic sclerosis is a rare connective tissue disease characterised by a wide range of clinical manifestations. Compared with previous sets of criteria, the 2013 American College of Rheumatology and European League Against Rheumatism (ACR/EULAR) classification of systemic sclerosis encompasses a broader and more relevant spectrum of the condition. Nonetheless, clinical and prognostic heterogeneity persists among patients fulfilling these criteria. The next task in the classification of systemic sclerosis is the development of new subset criteria that can successfully identify subgroups of patients with distinct prognostic or pathophysiological features. In this Viewpoint we describe the history of systemic sclerosis over the past century with the objective of highlighting the effect of previous nosological debates on efforts to understand and manage this disorder. Rather than seeking to present a systematic review of possible subgrouping for systemic sclerosis in relation to prognosis, we aim to clarify how nosological considerations have influenced our understanding of the cause and prognosis of this so-called idiopathic rheumatological disorder and how aetiological, prognostic, and pathophysiological hypotheses have helped to describe clusters within the disease. By reflecting on past nosological debates and endeavours, we identify challenges for the current initiative to develop a new subgrouping of systemic sclerosis.

Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis

Objective

Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained.

Methods

A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twenty‐four clinical and serologic variables were used for clustering.

Results

Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement.

Conclusion

Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis.

Thrombocytosis as a prognostic factor in polymyalgia rheumatica: characteristics determined from cluster analysis

Background:

This study aimed to identify the clinical subgroups of polymyalgia rheumatica (PMR) using cluster analysis and compare the outcomes among the identified subgroups.

Methods:

We enrolled patients with PMR who were diagnosed at Okayama University Hospital, Japan between 2006 and 2017, met the 2012 European League Against Rheumatism/American College of Rheumatology provisional classification criteria for PMR, and were treated with glucocorticoids. Hierarchical cluster analysis using variables selected by principal component analysis was performed to identify the clusters. Subsequently, the outcomes among the identified clusters were compared in the study. The primary outcome was treatment response at 1 month after commencement of treatment. The secondary outcome was refractory clinical course, which was defined as the requirement of additional treatments or relapse during a 2-year observational period.

Results:

A total of 61 consecutive patients with PMR were enrolled in the study. Their mean age was 71 years, and 67% were female. Hierarchical cluster analysis revealed three distinct subgroups: cluster 1 (n = 14) was characterized by patients with thrombocytosis (all patients showed a platelet count of >45 × 10⁴/µl), cluster 2 (n = 38), by patients without peripheral arthritis, and cluster 3 (n = 9), by patients with peripheral arthritis. The patients in cluster 1 achieved treatment response less frequently than those in cluster 2 (14% versus 47%, p = 0.030). Refractory cases were more frequent in cluster 1 than in cluster 2; however, no significant difference was noted (71% versus 42%, p = 0.06).

Conclusions:

Thrombocytosis could predict the clinical course in patients with PMR.

Clinical and laboratory features of African-Brazilian patients with systemic sclerosis

OBJECTIVE

African-Brazilians comprise a group of blacks and "pardos." As racial differences can be associated with distinct presentations, we evaluated the clinical and serological associations of African-Brazilians with systemic sclerosis (SSc).

METHODS

Sera from 260 adult SSc patients (203 whites and 57 African-Brazilians) were evaluated. Patients with overlap syndromes were excluded. Clinical and demographic data were obtained from an electronic register database. Laboratory analysis included the following: anti-CENP-A/CENP-B, Scl70, RNA polymerase III, Ku, fibrillarin, Th/To, PM-Scl75, and PM-Scl100 by line immunoassay and anti-nuclear antibodies (ANA) by indirect immunofluorescence (IIF) on HEp-2 cells.

RESULTS

African-Brazilian SSc patients presented shorter disease duration (12.8 ± 6.5 vs. 15.9 ± 8.1 years, p = 0.009), higher frequency of nucleolar ANA pattern (28% vs. 13%, p = 0.008), and lower frequencies of centromeric ANA pattern (14% vs. 29%, p = 0.026) and CENP-B (18% vs. 34%, p = 0.017), as well as an association with severe interstitial lung disease (58% vs. 43%; p = 0.044). Further comparison of ethnic groups according to subsets revealed that diffuse SSc African-Brazilian patients presented higher frequency of pulmonary hypertension (p = 0.017), heart involvement (p = 0.037), nucleolar ANA pattern (p = 0.036), anti-fibrillarin antibodies (p = 0.037), and higher mortality (48% vs. 19%; p = 0.009). A different pattern was observed for the limited subset with solely a lower frequency of esophageal involvement (p = 0.050) and centromeric ANA pattern (p = 0.049). Survival analysis showed that African-Brazilians had a higher mortality, when adjusted for age, gender, and clinical subset (RR 2.06, CI 95% 1.10-3.83, p = 0.023).

CONCLUSION

African-Brazilians have distinct characteristics according to clinical subset and an overall more severe SSc than whites, similar to the blacks from other countries.Key Points • African-Brazilian SSc patients were associated with severe interstitial lung disease and nucleolar ANA pattern when compared to white SSc patients. • When disease subsets were considered, African-Brazilian patients with diffuse SSc presented association with pulmonary hypertension, heart involvement, nucleolar ANA pattern, and anti-fibrillarin antibodies. • White SSc patients were associated with centromeric ANA pattern. • Survival analysis at 5, 10, 15, and 20 years, adjusted for age, gender, and disease subset, was significantly worse in African-Brazilian SSc patients.

Autoantibodies are present before the clinical diagnosis of systemic sclerosis

Systemic sclerosis (SSc) is a heterogeneous autoimmune disorder associated with vascular dysfunction and fibrotic changes in the skin, vasculature and internal organs. Although serologic abnormalities are an important diagnostic tool for SSc, little is known about whether autoantibodies precede clinical diagnosis. Here we investigated the presence of autoantibodies before SSc diagnosis and assessed whether certain autoantibodies might associate with the future onset of scleroderma renal crisis (SRC), a potentially fatal complication of the disease. Using the Department of Defense Serum Repository, autoantibodies were analyzed from archived, prospectively collected, longitudinal serum samples from sixteen individuals with SRC (SSc/SRC) and thirty cases of SSc without SRC (SSc/no SRC), matched for age, sex, and race. Seventy five percent (12/16) of the SSc/SRC and 40% (12/30) of the SSc/no SRC were seropositive for at least one autoantibody prior to clinical diagnosis (up to 27.1 years earlier, mean = -7.4 years). Although both disease groups demonstrated a heterogeneous immunoreactivity profile against the autoantigen panel, the SSc/SRC subjects showed two enriched clusters with one featuring elevated levels of autoantibodies against Ro52 and/or Ro60 and another with high levels of immunoreactivity against the RNA polymerase complex. Consistent with larger spectrum of immunoreactivity and the elevated levels of autoantibodies in SSc/SRC, the total response against the autoantigen panel from the last time point of the seropositive subjects revealed that the SSc/SRC cohort harbored higher antibody levels (p = 0.02) compared to SSc/no SRC. Overall, our findings demonstrate that relevant seropositive autoantibodies often precede the clinical diagnosis of SSc/no SRC and SSc/SRC.

Improving life expectancy of patients with scleroderma: results from the South Australian Scleroderma Register

BACKGROUND

Scleroderma is a rare connective tissue disorder characterised by inflammation, vasculopathy and excessive fibrosis. Patients with scleroderma are known to have decreased life expectancy.

AIM

To investigate changes in life expectancy in patients with scleroderma over a 30-year period.

METHODS

Utilising the South Australian Scleroderma Register, deceased patients were identified. We examined changes in age of death and duration of disease in these patients over three time periods: 1985-1994, 1995-2004 and 2005-2015. Analyses of scleroderma subtypes were performed, and comparisons were made to the general South Australian population.

RESULTS

A total of 413 deceased patients was identified. Females were overrepresented 315 to 98; 265 had limited scleroderma, 90 diffuse and 22 overlap disease. Over 30 years, the mean age of death improved from 66.4 to 74.5 years (P < 0.001). Duration of disease improved from 12.1 to 22.9 years (P < 0.001). Improvement in survival was seen in limited (P = 0.001), diffuse (P = 0.04) and overlap (P = 0.04) subgroups. The increase in survival was only seen for female (9.8 ± 4.2 years) but not male (1.4 ± 6.7 years) patients.

CONCLUSION

Over the last 30 years, survival has significantly improved for female but not male patients. As no disease-modifying drugs have consistently been shown to alter disease course, this improvement is likely attributable to general improvements in medical care, including that of scleroderma-related complications. While the life expectancy for limited disease is now close to that of the general population, patients with diffuse and overlap disease continue to suffer from significant early mortality.

Anti-RNA polymerase III antibodies in patients with suspected and definite systemic sclerosis: Why and how to screen

Anti-RNA Polymerase III antibodies are the most frequent anti-nuclear antibodies in systemic sclerosis, after anti-centromere and anti-Topoisomerase I. Considering their specificity for systemic sclerosis, they have been included in 2013 American College of Rheumatology/European League Against Rheumatism classification criteria for systemic sclerosis. They were first identified in 1993 using an immunoprecipitation method; the subsequent diffusion of commercial assays, based on the enzyme-linked immunosorbent assay or multiplex line immunoblot techniques, has allowed an increasing number of systemic sclerosis patients to be tested for this autoantibody; nevertheless, the diffusion of this test in systemic sclerosis patients is probably still sub-optimal. Anti-RNA Polymerase III antibodies have been associated with important clinical manifestations: rapid and diffuse cutaneous involvement, joint contractures, scleroderma renal crisis, gastric antral vascular ectasia and malignancies synchronous to systemic sclerosis onset. Moreover, other possible clinical associations, including pulmonary hypertension, still need confirmation. Since the correct approach for screening for anti- RNA Polymerase III antibodies in patients with suspected or definite systemic sclerosis is still debated, possible strategies are proposed here. Moreover, issues that are still controversial are discussed, including the interpretation of multiple simultaneous positivity for anti-RNA Polymerase III antibodies and other autoantibodies in line immunoassay, and the possible relevance of anti-RNA Polymerase III antibodies titre.

Determining the Risk Factors and Clinical Features Associated With Severe Gastrointestinal Dysmotility in Systemic Sclerosis

OBJECTIVE

A subset of patients with systemic sclerosis (SSc) develop severe gastrointestinal (GI) dysmotility. We sought to determine predictors of severe SSc GI dysmotility and to identify distinct features associated with this phenotype.

METHODS

Patients with SSc who required supplemental nutrition (enteral or parenteral tube feeding) were compared to SSc patients with mild GI symptoms in a cross-sectional analysis. The association between severe GI dysmotility and clinical and serologic features was examined using logistic regression. Baseline data were examined to determine predictors of developing severe GI dysfunction using Cox regression.

RESULTS

SSc patients with severe GI dysmotility (n = 66) were more likely than those patients with mild GI symptoms (n = 1,736) to be male (odds ratio [OR] 2.47 [95% confidence interval (95% CI) 1.34-4.56]; P = 0.004), and to have myopathy (OR 5.53 [95% CI 2.82-10.82]; P < 0.001), and sicca symptoms (OR 2.40 [95% CI 1.30-4.42]; P = 0.005), even after adjustment for potential confounders. Baseline features that were associated with the future development of severe GI dysfunction included male sex (hazard ratio [HR] 2.99 [95% CI 1.53-5.84]; P = 0.001) and myopathy (HR 5.08 [95% CI 2.21-11.67]; P < 0.001).

CONCLUSION

Distinct clinical features are present in SSc patients who are at risk of developing severe GI dysmotility. This finding is not only important clinically but also suggests that a unique pathologic process is at work in these patients.

Symptoms of Autonomic Dysfunction in Systemic Sclerosis Assessed by the COMPASS-31 Questionnaire

OBJECTIVE

Autonomic dysfunction is a known complication of systemic sclerosis (SSc) that can affect vascular tone, gastrointestinal (GI) motility, heart rate, and blood pressure control. We sought to quantify autonomic symptom burden in SSc, and to define the characteristics of patients with SSc and autonomic dysfunction.

METHODS

Patients with SSc were consecutively recruited during routine clinical visits at the Johns Hopkins Scleroderma Center and asked to complete the Composite Autonomic Symptom Score (COMPASS)-31 questionnaire, a validated tool to assess symptoms of autonomic dysfunction. We determined the relationship between various clinical and serological features of SSc and the total COMPASS-31 scores and domain-specific scores using the Student t test or Wilcoxon rank-sum test for dichotomous variables and linear regression analysis for continuous variables.

RESULTS

The study included 104 patients with SSc who completed the COMPASS-31 questionnaire. The mean COMPASS-31 score in this cohort was 24.9 ± 15.5, higher than COMPASS-31 scores from previously published healthy controls (8.9 ± 8.7). Compared to patients with mild or absent GI disease, patients with significant GI disease had higher scores across several subdomains of the COMPASS-31, including orthostatic intolerance (median 10.0 vs 0, p = 0.006) and secretomotor dysfunction (median 6.4 vs 4.3, p = 0.03). There was also a dose-response relationship between GI disease severity and autonomic symptom burden.

CONCLUSION

Symptoms of autonomic dysfunction are common in SSc. Patients with more severe GI disease in SSc report more symptoms of dysautonomia across many facets of the autonomic nervous system.

Risk Factors for Future Scleroderma Renal Crisis at Systemic Sclerosis Diagnosis

OBJECTIVE

Systemic sclerosis (SSc) is a disease of autoimmunity, fibrosis, and vasculopathy. Scleroderma renal crisis (SRC) is one of the most severe complications. Corticosteroid exposure, presence of anti-RNA polymerase III antibodies (ARA), skin thickness, and significant tendon friction rubs are among the known risk factors at SSc diagnosis for developing future SRC. Identification of additional clinical characteristics and laboratory findings could expand and improve the risk profile for future SRC at SSc diagnosis.

METHODS

In this retrospective cohort study of the entire military electronic medical record between 2005 and 2016, we compared the demographics, clinical characteristics, and laboratory results at SSc diagnosis for 31 cases who developed SRC after SSc diagnosis to 322 SSc without SRC disease controls.

RESULTS

After adjustment for potential confounding variables, at SSc diagnosis these conditions were all associated with future SRC: proteinuria (p < 0.001; OR 183, 95% CI 19.1-1750), anemia (p = 0.001; OR 9.9, 95% CI 2.7-36.2), hypertension (p < 0.001; OR 13.1, 95% CI 4.7-36.6), chronic kidney disease (p = 0.008; OR 20.7, 95% CI 2.2-190.7), elevated erythrocyte sedimentation rate (p < 0.001; OR 14.3, 95% CI 4.8-43.0), thrombocytopenia (p = 0.03; OR 7.0, 95% CI 1.2-42.7), hypothyroidism (p = 0.01; OR 2.8, 95% CI 1.2-6.7), Anti-Ro antibody seropositivity (p = 0.003; OR 3.9, 95% CI 1.6-9.8), and ARA (p = 0.02; OR 4.1, 95% CI 1.2-13.8). Three or more of these risk factors present at SSc diagnosis was sensitive (77%) and highly specific (97%) for future SRC. No SSc without SRC disease controls had ≥ 4 risk factors.

CONCLUSION

In this SSc cohort, we present a panel of risk factors for future SRC. These patients may benefit from close observation of blood pressure, proteinuria, and estimated glomerular filtration rate, for earlier SRC identification and intervention. Future prospective therapeutic studies could focus specifically on this high-risk population.

A systematic review of the epidemiology, disease characteristics and management of systemic sclerosis in Australian adults

OBJECTIVE

Australia has one of the highest prevalence rates of systemic sclerosis (SSc) worldwide. In order to highlight management deficiencies and key areas for further research, it is essential to understand its local epidemiological patterns, natural history, prognosis and mortality trends over time.

METHODS

To identify Australian SSc-specific information through a systematic review focusing on areas of epidemiology, disease characteristics, treatment, functional ability, disease burden and health-related quality of life (HRQoL).

RESULTS

MEDLINE, EMBASE and the Cochrane Library were searched on 14 September, 2016. All original full text articles on SSc in Australia were included. Of the 54 articles included in this review, the majority of studies recruited from South Australia, Victoria and New South Wales. The prevalence of SSc in Australia is increasing and is similar among the general population and the Aboriginal population. Despite improvements in care over the last three decades, morbidity and mortality remain high, with an overall standardized mortality ratio of 3.4 and a 10-year survival of 84% in a newly diagnosed patient. Cardiorespiratory manifestations are the leading cause of SSc-related death. Malignancy is the leading cause of non-SSc-related death. The role of autoantibodies in predicting disease subtype, visceral involvement and their use as a prognostic marker is becoming increasingly recognized.

CONCLUSION

Information on SSc in Australia, particularly unmet healthcare needs, HRQoL and economic burden, is limited. As a heterogenous condition, SSc requires a multi-disciplinary approach to care. Research aimed at quantifying HRQoL and burden of disease in Australia is essential for advocacy and resource allocation.

Innate Immunity in Systemic Sclerosis

PURPOSE OF REVIEW

Systemic sclerosis (SSc) is a heterogeneous autoimmune disease which has defined three hallmarks: Small vessel vasculopathy, production of autoantibodies and fibroblast dysfunction. The exact aetiology of the disease remains unknown, due to the complex nature of the cellular signalling pathways involved. However, there is strong and consistent evidence that the innate system, in particular toll-like receptor signalling, is contributing to the progression and perhaps onset of systemic sclerosis. In light of this evidence, this review examines the role of innate immunity in systemic sclerosis and where appropriate suggests avenues for therapeutic modulation in SSc.

RECENT FINDINGS

Multiple lines of evidence suggest that Toll-like receptors (TLRs) are dysregulated and emerging evidence suggests that many endogenous ligands are also elevated in the disease leading to 'sterile inflammation' and ultimately the induction of fibrosis. Currently, no effective therapy exists and exploiting the innate immune system perturbation may be one possible avenue. Innate immune dysregulation is key in SSc pathogenesis and may represent a novel target.

Disease-related autoantibody profile in patients with systemic sclerosis

BACKGROUND

Autoantibodies (autoAbs) help in diagnosis and predicting clinical phenotypes in systemic sclerosis (SSc).

AIM OF THE STUDY

To determine the clinical utility of 13 SSc-related autoAbs in SSc patients.

MATERIAL AND METHODS

A total of 131 consecutive patients with SSc (111 female, mean age 58.1 ± 14 years; 49 with diffused cutaneous SSc [dcSSc] and 82 with limited cutaneous SSc [lcSSc]) were analysed by a multiplex line immunoassay (Euroimmun) for autoantibodies (autoAbs) against 13 SSc-related antigens. A total of 22 patients with primary Raynaud phenomenon (RP), and 22 healthy controls were also analysed.

RESULTS

ANA by indirect immunofluorescence was present in 128 (97.7%) patients with SSc. Excluding anti-Ro52, 113 (89.3%) SSc patients were positive for at least one autoAb: anti-Topoisomerase I (anti-Topo) I abs in 54 (41.2%), anti-centromere proteins (anti-CENP) in 37 (28.2%, all reactive with centromere protein-A (CENPA) and centromere protein B (CENPB)), anti-RNA polymerase III(RP11) in 19 (14.5%), anti-RNA polymerase III(RP155) in 13 (9.9%), anti-fibrillarin in 4 (3.1%), anti-Ku in 6 (4.6%), anti-nucleolus-organizing region (anti-NOR90) in 8 (6.1%), anti-PM-Scl100 in 2 (1.5%), and anti-PM-Scl75 in 4 (3.1%). There was no immunoreactivity for Th/To or platelet-derived growth factor receptor (PDGFR). Overall, 102 (77.9%) SSc patients had autoAbs against Topo I, CENPA or CENPB, RP11 or RP155. Anti-Topo I abs were strongly associated with dcSSc, interstitial lung disease (ILD) (p < .001), pulmonary hypertension (PH) (p = .019) and ILD-PH (p = .003). Anti-CENPB abs were associated with lcSSc, and negatively associated with ILD. Anti-RP11 and anti-NOR90 abs were associated with male gender, and anti-NOR90 associated with ILD.

CONCLUSIONS

Anti-Topo I, anti-CENP, and anti-RNA pol III are the most prevalent autoAbs in SSc. Anti-Topo I and anti-NOR90 abs are associated with ILD and/or PAH.

Risk of Digital Vascular Events in Scleroderma Patients Who Have Both Anticentromere and Anti-Interferon-Inducible Protein 16 Antibodies

OBJECTIVE

To evaluate whether scleroderma patients who are double-positive for anti-interferon-inducible protein 16 (anti-IFI-16) antibodies and anticentromere (anti-CENP) antibodies are at increased risk for significant digital vascular events relative to patients positive for anti-CENP antibodies alone.

METHODS

Sera from 165 scleroderma patients who tested positive for anti-CENP antibodies upon clinical evaluation were reassayed for both anti-CENP and anti-IFI-16 antibodies using enzyme-linked immunosorbent assay testing. Patients who were positive for anti-CENP antibodies alone were then compared to patients who were double-positive for both anti-IFI-16 and anti-CENP antibodies. The association between a history of significant digital vascular events (digital pits, ischemic digital ulcers, and/or gangrene) and double-positive antibody status was examined using chi-square tests. After completion of univariate analysis, multivariable analyses were done to adjust for clinically relevant covariates.

RESULTS

Of the 165 anti-CENP antibody positive patients, 21 (12.7%) also had anti-IFI-16 antibodies. Patients who were double-positive for anti-CENP and anti-IFI-16 antibodies were more likely to have had digital pits, ischemic digital ulcers, and/or gangrene (P = 0.03). After adjustment for clinically relevant covariates (age, cutaneous subtype, disease duration, and smoking), double-positive patients remained at significantly higher odds of having severe Raynaud's phenomenon (odds ratio 3.5 [95% confidence interval 1.1-11.1]; P = 0.03).

CONCLUSION

Scleroderma patients who are double-positive for antibodies recognizing CENP and IFI-16 are significantly more likely to have significant digital vascular events during the course of their disease. This study provides further evidence that anti-CENP and anti-IFI-16 antibodies are disease biomarkers that may be used for risk stratification of vascular events in scleroderma.

Novel risk factors related to cancer in scleroderma

OBJECTIVE

Emerging data have shown an increased risk of malignancy among patients diagnosed with systemic sclerosis (SSc) so identification of risk factors linking both disorders might have prognostic implications. The aim of this study was to assess the clinical and treatment-related risk factors for cancer in a single-center cohort of patients with SSc.

METHODS

Demographic, clinical, capillaroscopic, immunological and treatment-related data from 432 consecutive SSc patients were retrospectively analyzed. Variables that reached significant association in the univariate analysis were entered into a logistic regression in order to identify independent risk factors for cancer.

RESULTS

Malignancy was diagnosed in 53 patients (12.2%). Fifty-eight neoplasms were identified, among which breast (n=15), lung (n=10) and hematologic (n=9) malignancies were the most prevalent. In 19 patients the diagnosis of both scleroderma and tumour was made in <3years apart. Cancer significantly decreased the probability of survival (OR=2.61; 95%CI 1.46-4.69; p=0.001). No association with age, sex, smoking, cutaneous subset or RNA polymerase-III antibodies was found. However, risk of cancer was directly associated with the presence of anti-PM/Scl antibodies (OR=3.90; 95%CI 1.31-11.61; p=0.014), and inversely related to aspirin use (OR=0.33; 95%CI 0.12-0.90; p=0.031), which remained as independent risk factors for cancer on multivariate analysis.

CONCLUSIONS

PM/Scl antibodies seem to be associated with a higher risk of cancer in scleroderma. In contrast, the use of aspirin is related to a lower risk of cancer in our series. More studies are needed to ascertain the role of anti PM/Scl antibodies and aspirin in the development of malignancy among patients with SSc.

Rheumatology around the world: perspectives from Australia and New Zealand

Rheumatology continues to be an exciting and vibrant specialty for specialists practising in New Zealand and Australia. Clinicians follow treat-to-target regimens to manage peripheral and axial inflammatory arthritides using conventional and biological agents, which have revolutionised management of rheumatic disease over the past two decades. However, optimal clinical practice has significant pharmacoeconomic implications which impact on health funding at a national level, and the advent of biosimilars is keenly awaited. The management of non-inflammatory rheumatic disease and the lack of effective disease-suppressing pharmacologic therapy for osteoarthritis continue to challenge clinicians. We are fortunate in having world-class rheumatology research in our region with basic scientists and clinical rheumatologists spearheading investigations, the ultimate aim of which is to improve the quality of life for our patients.

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.

Musculoskeletal Involvement in Systemic Sclerosis: An Unexplored Aspect of the Disease

Musculoskeletal (MSK) symptoms in patients with systemic sclerosis (SSc) include articular involvement (arthralgia, synovitis, contractures), which is often an early phenomenon and significantly contributes to the disability. Predominantly the hands are affected. Consensus in outcome measures of articular involvement is missing. Health Assessment Questionnaire Disability Index (HAQ-DI), Cochin Hand Function Scale (CHFS), Hand Mobility Index in Scleroderma (HAMIS), and Disease Activity Score of 28 Joints (DAS28) may be used for the assessment of different aspects of joint involvement. There is an unmet need for therapies confirmed by randomized controlled clinical trials (RCTs) to treat both synovitis and non-inflammatory joint involvement. The few rehabilitation studies that have been conducted have shown some promising efficacy.

Muscle involvement may be an early symptom. The presence of clinically meaningful muscle involvement often heralds an unfavourable prognosis. The histology of muscle biopsy shows a variable picture including inflammation and necrosis. Besides, signs of acute neurogenic atrophy have been recently described as a previously underestimated contributor to muscle weakness. Similar to articular involvement, the lack of classification criteria on inflammatory and non-inflammatory SSc-associated myopathies, and the lack of validated core set of outcome measures makes it difficult to perform RCTs.

The SSc-specific fibrinous tenosynovitis (tendon-friction rubs /TFRs/) is a frequent finding in SSc. Patients with TFR are at increased risk of developing renal, vascular, cardiac and gastrointestinal involvement and have reduced survival rates. Changes of fibrinous tenosynovitis can be objectively detected by ultrasound and may be used as an outcome measure in the treatment of MSK involvement.

Limited cutaneous systemic sclerosis: the unfairly neglected subset

Systemic sclerosis (SSc) is an autoimmune disease and a disabling condition that reduces life expectancy. Disease heterogeneity is a hallmark of SSc and classification has been hard to establish. Moreover, within the SSc spectrum, subsetting according to the extent of skin involvement has been universally accepted and is used both for research purposes but also for patient care. Therefore, limited cutaneous (lcSSc) and diffuse cutaneous (dcSSc), with different severity and survival, have been recognized for several years as distinct subsets. Any SSc research project using human material takes into account the cutaneous subsets but it is striking to see that the dcSSc subset has been the subject of the very large majority of the research projects so far. This editorial indicates the comparative epidemiology of the two cutaneous subsets and summarizes the main results coming from the recent registries about the respective outcomes of the patients. The data demonstrate the predominance of the lcSSc subset and challenge some ideas that could suggest that the lcSSc subset might be a benign condition. Some clues are also provided regarding the future possibility to enroll more patients having the lc subset in clinical trials and potential shared outcome measures.

Single-specificity anti-Ku antibodies in an international cohort of 2140 systemic sclerosis subjects: clinical associations

Autoantibodies directed against the Ku autoantigen are present in systemic sclerosis (SSc) and have been associated with myositis overlap and interstitial lung disease (ILD). However, there is a paucity of data on the clinical correlates of anti-Ku antibodies in the absence of other SSc-specific antibodies. The aim of this study was to assess the clinical correlates of single-specificity anti-Ku in SSc.An international (Canada, Australia, USA, Mexico) cohort of 2140 SSc subjects was formed, demographic and clinical variables were harmonized, and sera were tested for anti-Ku using a line immunoassay. Associations between single-specificity anti-Ku antibodies (i.e., in isolation of other SSc-specific antibodies) and outcomes of interest, including myositis, ILD, and survival, were investigated.Twenty-four (1.1%) subjects had antibodies against Ku, and 13 (0.6%) had single-specificity anti-Ku antibodies. Subjects with single-specificity anti-Ku antibodies were more likely to have ILD (58% vs 34%), and to have increased creatine kinase levels (>3× normal) at baseline (11% vs 1%) and during follow-up (10% vs 2%). No difference in survival was noted in subjects with and without single-specificity anti-Ku antibodies.This is the largest cohort to date focusing on the prevalence and disease characteristics of single-specificity anti-Ku antibodies in subjects with SSc. These results need to be interpreted with caution in light of the small sample. International collaboration is key to understanding the clinical correlates of uncommon serological profiles in SSc.

Systemic Sclerosis and Malignancy: A Review of Current Data

Systemic sclerosis (SSc) is associated with increased risk of malignancy. The organ systems most commonly affected are the lungs, the breasts and the hematological system. Risk factors predisposing a SSc patient for development of malignancy are not well defined, and the pathogenic basis of the association is yet to be explained. The incidence of malignancies in SSc patients is variable from one report to another, but most importantly, questions regarding the role of immunosuppressive therapies and the effect of autoantibodies have weak or sometimes contradictory answers in most of the currently available literature and physicians have no available guidelines to screen their SSc patients for malignancies. The lack of a concretely defined high-risk profile and the absence of malignancy screening guidelines tailored for SSc patients raise the importance of the need for more studies on the association of SSc and cancer and should incite rheumatology colleges to develop specific recommendations for the clinician to follow while approaching patients with SSc.

Longitudinal patterns of pain in patients with diffuse and limited systemic sclerosis: integrating medical, psychological, and social characteristics

PURPOSE

Pain is a common but understudied quality of life concern in systemic sclerosis (SSc). This investigation sought to describe patient-reported pain during the early phase of the disease and to examine potential predictors of this over time.

METHODS

A prospective cohort (N = 316) of patients with early-disease SSc from the Genetics versus ENvironment In Scleroderma Outcome Study (GENISOS) were followed for 3 years. Multilevel modeling was used to describe longitudinal changes in pain and the extent to which pain variance was explained by disease type, emotional health, perceived physical health, health worry, and social support.

RESULTS

Patient-reported pain remained relatively stable, with slight improvement over time. More severe disease type was associated with worse initial pain, but the association was reduced to nonsignificance after accounting for the psychosocial variables. Better emotional health and perceived physical health were associated with lower initial pain. There were marginal interactive effects for perceived physical health and social support such that initial perceptions of poorer physical health, and higher social support, were predictive of greater improvements in pain over time.

CONCLUSIONS

These data suggest that emotional health, perceived physical health, and social support are more relevant to longitudinal SSc pain than disease severity and that perceived physical health and social support may impact pain trajectories. Researchers and rheumatology health professionals should consider these factors in comprehensive pain models and pain management protocols.