A descriptive and prognostic study of systemic sclerosis-associated myopathies

Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis

OBJECTIVES

To clarify the impact of anti-U1RNP antibodies on the clinical features and prognosis of patients with SSc.

METHODS

We conducted a monocentric case-control, retrospective, longitudinal study. For each patient with SSc and anti-U1RNP antibodies (SSc-RNP+), one patient with mixed connective tissue disease (MCTD) and 2 SSc patients without anti-U1RNP antibodies (SSc-RNP-) were matched for age, sex, and date of inclusion.

RESULTS

Sixty-four SSc-RNP+ patients were compared to 128 SSc-RNP- and 64 MCTD patients. Compared to SSc-RNP-, SSc-RNP+ patients were more often of Afro-Caribbean origin (31.3% vs. 11%, p < 0.01), and more often had an overlap syndrome than SSc-RNP- patients (53.1 % vs. 22.7%, p < 0.0001), overlapping with Sjögren's syndrome (n = 23, 35.9%) and/or systemic lupus erythematosus (n = 19, 29.7%). SSc-RNP+ patients were distinctly different from MCTD patients but less often had joint involvement (p < 0.01). SSc-RNP+ patients more frequently developed interstitial lung disease (ILD) (73.4% vs. 55.5% vs. 31.3%, p < 0.05), pulmonary fibrosis (PF) (60.9% vs. 37.5% vs. 10.9%, p < 0.0001), SSc associated myopathy (29.7% vs. 6.3% vs. 7.8%, p < 0.0001), and kidney involvement (10.9% vs. 2.3% vs. 1.6%, p < 0.05). Over a 200-month follow-up period, SSc-RNP+ patients had worse overall survival (p < 0.05), worse survival without PF occurrence (p < 0.01), ILD or PF progression (p < 0.01 and p < 0.0001).

CONCLUSIONS

In SSc patients, anti-U1RNP antibodies are associated with a higher incidence of overlap syndrome, a distinct clinical phenotype, and poorer survival compared to SSc-RNP- and MCTD patients. Our study suggests that SSc-RNP+ patients should be separated from MCTD patients and may constitute an enriched population for progressive lung disease.

Proximal weakness and creatine kinase elevation in systemic sclerosis: Clinical correlates, prognosis and functional implications

OBJECTIVES

To determine the frequency, clinical correlates and implications of clinical evidence of muscle disease in systemic sclerosis (SSc).

METHODS

Australian Scleroderma Cohort Study participants with ≥1 creatine kinase (CK) and proximal power assessment were subdivided according to presence of proximal weakness (PW: proximal muscle power<5/5) and CK elevation(≥140IU/L). Participants were assigned to one of four groups: concurrent PW&CK elevation, PW alone, CK elevation alone or neither. Between-group comparisons were made with chi-squared, ANOVA or Kruskal-Wallis tests. Survival analysis was performed using time-varying-covariate Cox regression modelling. Longitudinal data were modelled using multinomial logistic and linear regression.

RESULTS

Of 1786 participants, 4 % had concurrent PW&CK elevation, 15 % PW alone, 24 % CK elevation and 57 % neither. Participants with PW&CK elevation displayed a severe, inflammatory SSc phenotype, with more frequent dcSSc(p < 0.01), tendon friction rubs(p < 0.01), synovitis(p < 0.01) and digital ulceration(p = 0.03). Multimorbidity(p < 0.01) and cardiopulmonary disease, including ischaemic heart disease(p < 0.01) and pulmonary arterial hypertension(p < 0.01), were most common in those with PW, with and without CK elevation. Men with anti-Scl70 positivity most frequently had CK elevation alone, without other significant clinical differences. Multivariable modelling demonstrated 3.6-fold increased mortality in those with PW&CK elevation (95 %CI 1.9-6.6, p < 0.01) and 2.1-fold increased mortality in PW alone (95 %CI 1.4-3.0, p < 0.01) compared to those without PW or CK elevation. CK elevation alone conferred better survival (HR 0.7, 95 %CI 0.4-1.1, p = 0.09) compared to those with no PW or CK elevation. PW regardless of CK elevation was associated with impaired physical function, with reduced six-minute-walk-distance (p < 0.01), higher HAQ-DI scores (p < 0.01) and increased patient-reported dyspnoea (p = 0.04).

CONCLUSION

Clinical features of myopathy are highly prevalent in SSc, affecting almost half of our study cohort. Detection of PW and elevated CK alone, even without imaging or histopathological identification of SSc-myopathy, identified important clinical associations and are associated with poorer function and overall prognosis.

Consensus statement on the diagnosis and treatment of sclerosing diseases of the skin, Part 1: Localized scleroderma, systemic sclerosis and overlap syndromes

The term 'sclerosing diseases of the skin' comprises specific dermatological entities, which have fibrotic changes of the skin in common. These diseases mostly manifest in different clinical subtypes according to cutaneous and extracutaneous involvement and can sometimes be difficult to distinguish from each other. The present consensus provides an update to the 2017 European Dermatology Forum Guidelines, focusing on characteristic clinical and histopathological features, diagnostic scores and the serum autoantibodies most useful for differential diagnosis. In addition, updated strategies for the first- and advanced-line therapy of sclerosing skin diseases are addressed in detail. Part 1 of this consensus provides clinicians with an overview of the diagnosis and treatment of localized scleroderma (morphea), and systemic sclerosis including overlap syndromes.

Myositis mimics in scleroderma: A case series of neuromuscular diseases that can co-exist in scleroderma

We present a case series of four patients with systemic sclerosis and skeletal myopathy. While idiopathic inflammatory myopathies, or myositis, are thought to be the most common type of muscle disease seen in systemic sclerosis, we highlight four cases where unique clinical findings and careful assessment ruled out myositis mimics. Key diagnostic tools that can be helpful for clinicians to diagnose a neuromuscular disease are also detailed in this report.

Systemic sclerosis associated myopathy: how to treat

Purpose of review

Systemic sclerosis (SSc) and myositis are two different entities that may coexist as an overlap syndrome. Immunological biomarkers such as anti-PM/Scl or anti-Ku reinforce the syndrome. This review is focused on the treatment of different and characteristic manifestations of this syndrome.

Recent findings

Among the different phenotypes of muscle involvement in patients with SSc, the fibrotic pattern and the sporadic inclusion body myositis must be identified early to avoid a futile immunosuppressive treatment. Other forms such as dermatomyositis, non-specific myositis and immune-mediated necrotizing myopathy need to receive conventional immunosuppressive therapy considering that high dose of glucocorticoids may induce a scleroderma renal crisis in patients with SSc. Physicians must be aware of the existence of a "double trouble" association of hereditary myopathy with an autoimmune phenomenon. Several autoantibodies, mainly anti-PM/Scl and anti-Ku may help to define specific phenotypes with characteristic clinical manifestations that need a more specific therapy. Vasculopathy is one of the underlying mechanisms that link SSc and myositis. Recent advances in this topic are reviewed.

Summary

Current treatment of SSc associated myopathy must be tailored to specific organs involved. Identifying the specific clinical, pathological, and immunological phenotypes may help to take the correct therapeutic decisions.

Myopathy in systemic sclerosis

PURPOSE OF REVIEW

Systemic sclerosis associated myopathy (SSc-AM) is a complex, heterogenous disease that is associated with poor outcomes. SSc-AM lacks a clear definition, and continues to be poorly recognized. The purpose of this review is to provide a contemporary overview of the clinical, serological and pathophysiologic findings in SSc-AM to guide optimal recognition and management of this challenging disease manifestation.

RECENT FINDINGS

There have been several advances in diagnostic techniques to facilitate characterization of SSc-AM, including muscle MRI, in which findings were correlated to distinct histopathologic categories of muscle involvement in SSc, histopathologic findings of prominent fibrosis or inflammation on biopsy, and the identification of novel autoantibodies associated with SSc-AM, which may be associated with distinct clinical phenotypes. In one of the largest studies to date, 17% of a well phenotyped SSc cohort were found to have myopathy, which was an independent risk of death, even after adjusting for potential confounders, further highlighting the importance of timely recognistion and management of SSc-AM.

SUMMARY

There is increasing recognition of the importance of SSc-AM. Novel diagnostic tools provide the opportunity for more detailed insights into pathophysiologic mechanisms, which may facilitate the development of a rigorous consensus definition of SSc-AM.

Multi-Organ System Screening, Care, and Patient Support in Systemic Sclerosis

Systemic sclerosis (SSc) is a heterogenous systemic autoimmune disease of complex multi-organ manifestations with a disease-specific mortality of >50%. The patient journey is fraught with severe, diverse, and diffuse physical impairment, psychological burden, and diminishing health-related quality of life. SSc remains unfamiliar to many clinicians. Delayed/misdiagnosis, inadequate screening, and attention for common complications with potentially preventable disability/death contribute to patients feeling isolated and unsupported. We present actionable standards including screening, anticipatory guidance, and counseling in patient-centered SSc-care emphasizing psycho-social health as the central goal, whereas robust vigilance and efforts to improve biophysical health and survival are imperatives that support this goal.

Systemic sclerosis associated myopathy

Scleroderma associated myopathy (SScAM) is a common but heterogeneous musculoskeletal manifestation of systemic sclerosis (SSc) for which there is still no clear definition. Still, SScAM is associated with disability, poor quality of life and mortality. This review discusses the most updated literature of SScAM including clinical and antibody associations, recent updates on histopathological findings, prognosis and treatment.

Disease specific determinants of cardiopulmonary fitness in systemic sclerosis

OBJECTIVES

We aimed to quantify the burden of exercise intolerance in systemic sclerosis (SSc) and explore the disease features that contribute to impaired exercise capacity (measured as peak oxygen uptake, peak VO₂) to provide novel mechanistic insights into the causes of physical disability in SSc.

METHODS

Thirty-three SSc patients with no history of cardiac disease and no active myositis underwent cardiac and skeletal muscle MRI, transthoracic echocardiography, pulmonary function tests and cardiopulmonary exercise testing (CPET). CPET results were compared to an age-, sex-, and weight-matched controls with no overt cardiopulmonary disease. Native T1 and T2-mapping sequences were used to quantify diffuse fibroinflammatory myocardial disease and qualitative assessment of skeletal muscle oedema was performed. The associations between parameters of cardiorespiratory function and skeletal muscle abnormalities and peak VO₂ were evaluated with linear regression analysis.

RESULTS

Exercise capacity was markedly impaired in SSc and significantly reduced when compared to control subjects (percent predicted peak VO₂: 70% vs 98%, p < 0⋅01). Diffuse myocardial fibroinflammatory disease (p < 0⋅01) and skeletal muscle oedema (p = 0⋅01) were significantly associated with reduced exercise capacity. There was no association between impaired exercise capacity and left ventricular ejection fraction.

CONCLUSION

SSc is associated with marked functional impairment that is not explained by commonly used parameters of cardiac function such as left ventricular ejection fraction. Rather, only more sensitive measures of organ involvement are associated with impaired exercise tolerance. Our results show diffuse interstitial changes of the myocardium and skeletal muscle affect oxygen uptake and are important contributors to functional limitation in SSc.

Scleromyositis: A distinct novel entity within the systemic sclerosis and autoimmune myositis spectrum. Implications for care and pathogenesis

Systemic sclerosis and autoimmune myositis are both associated with decreased quality of life and increased mortality. Their prognosis and management largely depend on the disease subgroups. Indeed, systemic sclerosis is a heterogeneous disease, the two predominant forms of the disease being limited and diffuse scleroderma. Autoimmune myositis is also a heterogeneous group of myopathies that classically encompass necrotizing myopathy, antisynthetase syndrome, dermatomyositis and inclusion body myositis. Recent data revealed that an additional disease subset, denominated "scleromyositis", should be recognized within both the systemic sclerosis and the autoimmune myositis spectrum. We performed an in-depth review of the literature with the aim of better delineating scleromyositis. Our review highlights that this concept is supported by recent clinical, serological and histopathological findings that have important implications for patient management and understanding of the disease pathophysiology. As compared with other subsets of systemic sclerosis and autoimmune myositis, scleromyositis patients can present with a characteristic pattern of muscle involvement (i.e. distribution of muscle weakness) along with multisystemic involvement, and some of these extra-muscular complications are associated with poor prognosis. Several autoantibodies have been specifically associated with scleromyositis, but they are not currently integrated in diagnostic and classification criteria for systemic sclerosis and autoimmune myositis. Finally, striking vasculopathic lesions at muscle biopsy have been shown to be hallmarks of scleromyositis, providing a strong anatomopathological substratum for the concept of scleromyositis. These findings bring new insights into the pathogenesis of scleromyositis and help to diagnose this condition, in patients with subtle SSc features and/or no autoantibodies (i.e. "seronegative" scleromyositis). No guidelines are available for the management of these patients, but recent data are showing the way towards a new therapeutic approach dedicated to these patients.

The Involvement of Smooth Muscle, Striated Muscle, and the Myocardium in Scleroderma: A Review

Systemic sclerosis (SSc) is a complex autoimmune disease characterized by heterogeneous changes involving numerous organs and systems. The currently available data indicate that muscle injury (both smooth and striated muscles) is widespread and leads to significant morbidity, either directly or indirectly. From the consequences of smooth muscle involvement in the tunica media of blood vessels or at the level of the digestive tract, to skeletal myopathy (which may be interpreted strictly in the context of SSc, or as an overlap with idiopathic inflammatory myopathies), muscular injury in scleroderma translates to a number of notable clinical manifestations. Heart involvement in SSc is heterogenous depending on the definition used in the various studies. The majority of SSc patients experience a silent form of cardiac disease. The present review summarizes certain important features of myocardial, as well as smooth and skeletal muscle involvement in SSc. Further research is needed to fully describe and understand the pathogenic pathways and the implications of muscle involvement in scleroderma.

Capillary pathology with prominent basement membrane reduplication is the hallmark histopathological feature of scleromyositis

AIMS

To perform ultrastructural and histopathological analysis of muscle biopsies from a large group of systemic sclerosis (SSc) patients, including some with early/mild SSc features, and examine whether capillary pathology differentiates 'scleromyositis' (SM) from other auto-immune myositis (AIM) subsets.

METHODS

Muscle biopsies from a total of 60 SM patients and 43 AIM controls from two independent cohorts were examined by electron microscopy, collagen-4 immunofluorescence (Col4IF) and routine light microscopy.

RESULTS

Ultrastructural examination revealed prominent capillary basement membrane (BM) reduplication (4+ layers in >50% of capillaries) in 65% of SM vs 0% of AIM controls (p<0.001). In SM cases without prominent BM reduplication, capillary dilation was the most distinctive feature, present in 8% of capillaries in SM vs 2% in controls (p=0.001). Accumulation of ensheathed pericyte processes was another characteristic feature of SM and closely correlated with the degree of BM reduplication (r=0.833, p<0.001). On light microscopy, BM marker Col4IF revealed more frequent capillary enlargement in SM than in controls (84% vs 21%, p<0.001). SM cases were classified as non-inflammatory myopathy (36%), non-specific myositis (33%) or immune-mediated necrotizing myopathy (31%), but despite this histopathological heterogeneity, prominent BM reduplication remained a constant finding. In the 16 SM patients with early/mild SSc features, 63% showed prominent BM reduplication.

CONCLUSIONS

These results show that capillary pathology, and in particular prominent capillary BM reduplication, is the hallmark histopathological feature of SM even in patients with early/mild SSc and support the concept of SM as an organ manifestation of SSc and a distinct subset of AIM.

Elevated baseline serum creatine kinase in Thai early systemic sclerosis patients is associated with high incidence of cardiopulmonary complications and poor survival: an inception cohort study

BACKGROUND

Inception cohort data regarding the incidence of cardiopulmonary complications in early systemic sclerosis (SSc) patients comparing those with and without elevated baseline creatine kinase (CK) are limited. This study aimed to compare the incidence of cardiopulmonary complications and survival between the two subgroups.

METHODS

We used an inception cohort study of early SSc patients seen at the Rheumatology Clinic, Maharaj Nakorn Chiang Mai Hospital, Thailand, from January 2010 to December 2019. All patients were assessed for clinical manifestations and CK levels and underwent echocardiography and HRCT at the study entry and annually thereafter.

RESULTS

A total of 144 SSc patients (84 female, 115 diffuse cutaneous SSc (DcSSc)) with a mean disease duration of 11.9 ± 9.2 months were enrolled. At cohort entry, their mean ± SD CK levels were 364.3 ± 598.0 U/L. The participants were then divided into two subgroups: (i) 29 SSc with elevated CK (baseline CK ≥ 500 U/L); (ii) 115 SSc with non-elevated CK. At enrollment, the elevated CK group was characterized by a higher proportion of male gender, DcSSc subtype, arthritis, and weakness; shorter disease duration; and higher MRSS compared with non-elevated CK. At the last visit, with a mean ± SD follow-up duration of 6.2 ± 2.7 years, the elevated CK group showed a higher cumulative prevalence of weakness, dysphagia, LVEF < 50%, and suspected myocardial disease; higher incidence of LVEF < 50%, suspected myocardial disease, and ILD; and shorter survival time.

CONCLUSION

It was found in our study cohort that elevated baseline serum CK in early SSc, of which majority were DcSSc subtype, is associated with more severe clinical presentation, higher incidence of cardiopulmonary complications, and shorter survival time compared with the non-elevated CK subgroup. Key Points • In early SSc patients, elevated baseline serum creatine kinase was confirmed to be associated with a high incidence of cardiac and ILD complications, and poor long-term survival time. • Careful evaluation of baseline serum CK levels in all early-diagnosed SSc patients is crucial in general clinical practice.

Using magnetic resonance imaging to map the hidden burden of muscle involvement in systemic sclerosis

BACKGROUND

Skeletal muscle can be directly affected by systemic sclerosis (SSc); however, a significant burden of SSc-associated myopathy is undetected because clinical parameters such as weakness and creatine kinase (CK) are unreliable biomarkers of muscle involvement. This study presents qualitative and quantitative magnetic resonance imaging (MRI) findings that quantify the prevalence of myopathy and evaluate any association between skeletal and cardiac muscle involvement in SSc.

METHODS

Thirty-two patients with SSc who fulfilled the 2013 American College of Rheumatology/European League Against Rheumatism classification criteria underwent skeletal muscle MRI in addition to cardiac MRI. Skeletal muscles were independently assessed by two musculoskeletal radiologists for evidence of oedema, fatty infiltration and atrophy. Skeletal muscle T2 mapping times and percentage fat fraction were calculated. Linear regression analysis was used to evaluate the clinical and myocardial associations with skeletal muscle oedema and fatty infiltration. Cardiac MRI was performed using post gadolinium contrast imaging and parametric mapping techniques to assess focal and diffuse myocardial fibrosis.

RESULTS

Thirteen participants (40.6%) had MRI evidence of skeletal muscle oedema. Five (15.6%) participants had fatty infiltration. There was no association between skeletal muscle oedema and muscle strength, creatine kinase, inflammatory markers or fibroinflammatory myocardial disease. Patients with skeletal muscle oedema had higher T2-mapping times; there was a significant association between subjective assessments of muscle oedema and T2-mapping time (coef 2.46, p = 0.02) and percentage fat fraction (coef 3.41, p = 0.02). Diffuse myocardial fibrosis was a near-universal finding, and one third of patients had focal myocardial fibrosis. There was no association between skeletal myopathy detected by MRI and burden of myocardial disease.

CONCLUSIONS

MRI is a sensitive measure of muscle oedema and systematic assessment of SSc patients using MRI shows that myopathy is highly prevalent, even in patients without symptoms or other signs of muscle involvement. Similarly, cardiac fibrosis is highly prevalent but occurs independently of skeletal muscle changes. These results indicate that novel quantitative MRI techniques may be useful for assessing sub-clinical skeletal muscle disease in SSc.

The Role of the Multidisciplinary Health Care Team in the Management of Patients with Systemic Sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterised by immune dysfunction, vascular damage and fibrosis affecting the skin and multiple internal organs. The clinical spectrum of SSc is wide and its manifestations may lead to severe morbidity and mortality, in addition to a great impact on patients’ quality of life. Due to the multifaceted clinical manifestations of SSc, its management requires a combined expertise of different medical specialists to guarantee an adequate disease control and prevent organ complications. Multi-disciplinary teams (MDT), which are composed by physicians and other specialized health professionals, represent therefore a key element for the comprehensive management of SSc patients. Moreover, MTD can improve communication and patients’ empowerment while the presence of dedicated nurses can help patients to ask questions about their condition. The scope of this narrative review is to analyse the available evidences regarding the role of MDT in the management of SSc patients, and how this holistic approach may improve different disease domains and the overall prognosis. MDT regarding the cardiovascular and lung complication are the more represented in literature, given the great impact in prognosis. Nonetheless, MDT have been shown to be fundamental also in other disease domains as they can intercept early manifestations, thus stratifying patients based on the individual risks in order to personalize patients’ follow-up. MDTs may also minimize the treatment delay, enabling fast-track specialist referral. On the other hand, there are few trials specifically studying MDT in SSc and several authors have highlight the lack of standardization.

Treatment of systemic sclerosis

Systemic sclerosis (SSc) is a rare connective tissue disease characterized by skin and visceral fibrosis, vascular hyperreactivity and obliterative vasculopathy. Some of its complications such as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH) and heart involvement can be life-threatening and are associated with a high mortality and a poor prognosis. Many clinical trials were carried out in order to improve the survival and prognosis of SSc patients. The management of SSc is based on the frequent and regular assessment of the potential organ damage, and if present, the establishment of graduated pharmacological therapeutic strategies, associated with non-pharmacological procedures. Several randomized clinical trials have showed significant positive outcomes regarding some specific involvements. Many advances have been made, especially in the field of targeted therapies and personalized medicine, based on specific characteristics of the patient and the SSc.

A comprehensive framework for navigating patient care in systemic sclerosis: A global response to the need for improving the practice of diagnostic and preventive strategies in SSc

Systemic sclerosis (SSc), the most lethal of rheumatologic conditions, is the cause of death in >50% of SSc cases, led by pulmonary fibrosis followed by pulmonary hypertension and then scleroderma renal crisis (SRC). Multiple other preventable and treatable SSc-related vascular, cardiac, gastrointestinal, nutritional and musculoskeletal complications can lead to disability and death. Vascular injury with subsequent inflammation transforming to irreversible fibrosis and permanent damage characterizes SSc. Organ involvement is often present early in the disease course of SSc, but requires careful history-taking and vigilance in screening to detect. Inflammation is potentially reversible provided that treatment intensity quells inflammation and other immune mechanisms. In any SSc phenotype, opportunities for early treatment are prone to be under-utilized, especially in slowly progressive phenotypes that, in contrast to severe progressive ILD, indolently accrue irreversible organ damage resulting in later-stage life-limiting complications such as pulmonary hypertension, cardiac involvement, and malnutrition. A single SSc patient visit often requires much more physician and staff time, organization, vigilance, and direct management for multiple organ systems compared to other rheumatic or pulmonary diseases. Efficiency and efficacy of comprehensive SSc care enlists trending of symptoms and bio-data. Financial sustainability of SSc care benefits from understanding insurance reimbursement and health system allocation policies for complex patients. Sharing care between recognised SSc centers and local cardiology/pulmonary/rheumatology/gastroenterology colleagues may prevent complications and poor outcomes, while providing support to local specialists. As scleroderma specialists, we offer a practical framework with tools to facilitate an optimal, comprehensive and sustainable approach to SSc care. Improved health outcomes in SSc relies upon recogntion, management and, to the extent possible, prevention of SSc and treatment-related complications.

Exercise as a multi-modal disease-modifying medicine in systemic sclerosis: An introduction by The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis (G-FoRSS)

Systemic sclerosis (SSc) is a heterogeneous multisystem autoimmune disease whereby its main pathological drivers of disability and damage are vascular injury, inflammatory cell infiltration, and fibrosis. These mechanisms result in diffuse and diverse impairments arising from ischemic circulatory dysfunction leading to painful skin ulceration and calcinosis, neurovascular aberrations hindering gastrointestinal (GI) motility, progressive painful, incapacitating or immobilizing effects of inflammatory and fibrotic effects on the lungs, skin, articular and periarticular structures, and muscle. SSc-related impairments impede routine activities of daily living (ADLs) and disrupt three critical life areas: work, family, social/leisure, and also impact on psychological well-being. Physical activity and exercise are globally recommended; however, for connective tissue diseases, this guidance carries greater impact on inflammatory disease manifestations, recovery, and cardiovascular health. Exercise, through myogenic and vascular phenomena, naturally targets key pathogenic drivers by downregulating multiple inflammatory and fibrotic pathways in serum and tissue, while increasing circulation and vascular repair. G-FoRSS, The Global Fellowship on Rehabilitation and Exercise in Systemic Sclerosis recognizes the scientific basis of and advocates for education and research of exercise as a systemic and targeted SSc disease-modifying treatment. An overview of biophysiological mechanisms of physical activity and exercise are herein imparted for patients, clinicians, and researchers, and applied to SSc disease mechanisms, manifestations, and impairment. A preliminary guidance on exercise in SSc, a research agenda, and the current state of research and outcome measures are set forth.

Brachio-cervical inflammatory myopathy associated with systemic sclerosis. Case series and review of literature

This study was aimed at describing a case series of brachio-cervical inflammatory myopathy (BCIM) associated with systemic sclerosis (SSc), due to its rarity and limited coverage in published data. Another aim was to provide a literature review. We reported four cases of BCIM-SSc from our tertiary center. In addition, we researched the literature and found six articles featuring 17 patients who fit this phenotype. We pooled all cases and reported their features. Most patients were female and had limited SSc, and the median time of BCIM presentation was three years after SSc diagnosis. Asymmetric muscle involvement, scapular winging, dropped head, axial weakness, camptocormia, dysphagia, and dermatomyositis stigmas were common features. All patients had esophageal involvement. Most had positive antinuclear antibody results, a scleroderma pattern in their capillaroscopy images, elevated serum creatine phosphokinase, myopathic electrophysiology, and muscle involvement in magnetic resonance imaging. Muscle histopathological findings varied widely, but in general all showed the presence of lymphoid infiltrates, muscle atrophy, increased MHC-I expression, MAC deposits, vasculopathy, and muscle fiber necrosis. The response to immunosuppressive therapy was highly irregular. BCIM-SSc is a rare disorder that shares many similar phenotypes among the described cases, but has a highly heterogeneous response to treatment. At present, more data on the physiopathology, clinical features, and treatment is still needed.

First pilot study of extracellular volume MRI measurement in peripheral muscle of systemic sclerosis patients suggests diffuse fibrosis

OBJECTIVES

Peripheral muscle involvement in systemic sclerosis (SSc) may comprise myositis or a non-inflammatory myopathy. There is little understanding on the nature of SSc myopathy. This pilot study aimed to evaluate for the presence of diffuse fibrosis in the peripheral muscle of patients with SSc by determining extracellular volume (ECV) MRI measurement.

METHODS

SSc patients, with suspected myopathy or no muscle involvement, and healthy volunteers (HV) had native T1 and ECV MRI quantification of the thigh and creatine-kinase (CK) measured. Suspected myopathy was defined as current/history of minimally raised CK (<600 IU/l) +/- presence of clinical signs-symptoms (proximal muscle weakness and/or myalgia) +/- a Manual Muscle Testing score <5 in the thighs.

RESULTS

12 SSc patients and 10 HV were recruited. 9/12 patients had limited cutaneous SSc, 4/12 interstitial lung disease, 7/12 suspected myopathy. Higher skeletal muscle ECV was recorded in SSc patients compared to HV [mean (SD) 23(11)%, vs 11(4)% p = 0.04].Peripheral muscle ECV associated with CK (rho=0.554, p = 0.061) and was higher in SSc patients with myopathy compared to those with no myopathy [mean (SD) 28 (10) vs 15 (5), p = 0.023]. An ECV of 22% was determined to best identify myopathy with a sensitivity of 71% and a specificity of 80%.

CONCLUSION

This hypothesis-generating study showed higher ECV in SSc patients compared to HV as well as association of ECV with suspected myopathy, suggesting the presence of diffuse fibrosis in the peripheral muscle of SSc patients. Further studies are needed to understand the nature of SSc myopathy.

Autoantibody profiles delineate distinct subsets of scleromyositis

OBJECTIVE

Scleromyositis remains incompletely characterized owing in part to its heterogeneity. The purpose of this study was to explore the role of autoantibody profiles to define subsets of scleromyositis.

METHODS

Subjects with scleromyositis from a prospective cohort were divided into 3 groups based on autoantibody profiles: subjects with SSc-specific autoantibodies (anti-centromere, -topoisomerase 1, -RNA polymerase III, -Th/To, -fibrillarin), subjects with SSc-overlap autoantibodies (anti-PM/Scl, -U1RNP, -Ku), and subjects without SSc-related autoantibodies. Clinical features, laboratory tests, and histopathological findings were retrieved and compared between groups.

RESULTS

Of 42 scleromyositis subjects (79% female, mean age at diagnosis 55 years, mean disease duration 3.5 years), 8 (19%) subjects had SSc-specific autoantibodies, 14 (33%) SSc-overlap autoantibodies and 20 (48%) had no SSc-related autoantibodies. One-third had no skin involvement, a finding more frequent in the SSc-overlap subjects and those without SSc-related autoantibodies. Proximal and distal weakness was common and head drop/bent spine was found in 50% of the SSc-specific and 35% of the subjects without SSc-related autoantibodies. Of note, the group without SSc-related autoantibodies had the only cases of severe cardiac systolic dysfunction (n = 1) and scleroderma renal crisis (n = 1), as well as 3 out of the 4 cancers and 3 out of the 4 deaths.

CONCLUSION

In this carefully phenotyped series of scleromyositis subjects, absence of SSc-related autoantibodies was common and associated with distinct features and poor prognosis. Future studies are needed to validate these results and possibly identify novel autoantibodies or other biomarkers associated with scleromyositis.

Histopathological features of systemic sclerosis-associated myopathy: A scoping review

BACKGROUND

Scleromyositis (SM) is an emerging subset of myositis associated with features of systemic sclerosis (SSc) but it is currently not recognized as a distinct histopathological subset by the European NeuroMuscular Center (ENMC). Our aim was to review studies reporting muscle biopsies from SSc patients with myositis and to identify unique histopathological features of SM.

METHODS

A scoping review was conducted and included all studies reporting histopathological findings in SSc patients with myositis searching the following databases: PubMed, MEDLINE, EMBASE, CINAHL and EBM-Reviews. Clinical, serological, and histopathological data were extracted using a standardized protocol.

RESULTS

Out of 371 citations, 77 studies that included 559 muscle biopsies were extracted. Fifty-seven percent (n = 227/400) had inflammatory infiltrates, predominantly T cells, which were endomysial (49%), perimysial (42%) and perivascular (41%). Few studies (18%, n = 8/44) evaluated the presence of B-cells. Myofiber atrophy was present in 48% (n = 104/218) of biopsies, and was predominantly perifascicular in 19% (n = 6/31), with necrosis reported in 56% (n = 162/290) of cases. Sarcolemmal MHC-I upregulation was found in 72% (n = 64/89) of biopsies. Non-specified C5b-9 deposition was described in 39% of muscle biopsies (n = 28/72). Neurogenic features were present in 23% (n = 44/191); endomysial fibrosis was reported in 35% (n = 120/340); and rimmed vacuoles were observed in 32% (n = 11/34) of biopsies. Capillaropathy, such as capillary dropout and/or ultrastructural endothelial abnormalities, was reported in 33% (n = 43/129) of cases. Reported ENMC categories were mainly polymyositis (21%), non-specific myositis (19%), immune-mediated necrotizing myopathy (16%), and dermatomyositis (8%). Histopathological features were analyzed according to serological subtypes in 28 studies, including anti-PM-Scl (n = 48), -Ku (n = 23) and -U1RNP (n = 90). Most of these biopsies demonstrated inflammatory infiltrates (range 49-85%) as well as MHC-I expression (range 63-81%). Necrosis was associated with anti-Ku (85%) and anti-U1RNP (73%), while anti-Ku was also associated with neurogenic features and rimmed vacuoles in 57% and 25% of cases, respectively.

CONCLUSION

Our review suggests that SM is characterized by heterogeneous pathological features using definitions included in current histopathological criteria. Whether a distinct histopathological signature exists in SM remains to be determined. SSc-specific and SSc-associated autoantibodies may help define more homogeneous histopathological subsets.

[A case of anti-Th/To antibody-positive systemic sclerosis with muscle symptoms and interstitial pneumonia]

A 62-year-old Japanese man with swollen fingers and walking difficulty due to myalgia and muscle weakness in proximal limb muscles was admitted to our hospital. Serum creatine kinase was remarkably increased (7,380 U/l) and rapidly progressing interstitial pneumonia developed. Muscle biopsy showed necrotic and regenerating fibers without mononuclear infiltration and fibrosis. Anti-Th/To antibodies were detected in the serum, and anti-Th/To antibody-positive systemic sclerosis was diagnosed. Anti-Th/To antibody-positive sclerosis-associated myopathy has not yet been reported in the literature. The present case suggests that anti-Th/To antibody-positive systemic sclerosis can be accompanied by immune-mediated necrotizing myopathy and be effectively treated with immunotherapy comprising corticosteroids, tacrolimus and immunoglobulin.

The clinicoserological spectrum of inflammatory myopathy in the context of systemic sclerosis and systemic lupus erythematosus

The autoimmune rheumatic diseases (ARDs) are characterised by a pathological triad composed of autoimmunity/inflammation, microangiopathy and aberrant tissue remodelling. Disease terms such as idiopathic inflammatory myopathy (IIM), scleroderma/systemic sclerosis (SSc), and systemic lupus erythematosus (SLE) are helpful clinically but disguise the considerable overlap that exists within these 'distinct' disorders. This is perhaps best demonstrated by inflammatory myopathy, which can be present in SSc or SLE, but can itself be absent in clinically amyopathic IIM. Archetypal clinical manifestations of ARD (such as Raynaud's phenomenon) are frequently present, albeit with varying prominence, within each of these diseases. This is certainly the case for inflammatory myositis, which has long been recognised as an important clinical feature of both SSc and SLE. Progress in elucidating the clinicoserological spectrum of autoimmune rheumatic diseases has identified autoantibody specificities that are strongly associated with 'overlap' disease and the presence of inflammatory myositis in SSc and SLE. In this review, we shall describe the prevalence, burden, prognostic value and management considerations of IIM in the context of both SSc and SLE. A major emphasis on the value of autoantibodies shall highlight the value of these tools in predicting the future occurrence of inflammatory myositis in both SSc and SLE. Where applicable, unmet research needs shall be highlighted. The review emphasises the importance of myopathy as a common feature across all the ARDs, and highlights specific antibody specificities that are strongly associated with myopathy in the context of SLE and SSc.

Rheumatic manifestations of COVID-19: a systematic review and meta-analysis

BACKGROUND

Different proportions of musculoskeletal or autoimmune manifestations associated with COVID-19 have been reported in literature. We performed a systematic review and meta-analysis with the aim of assessing the prevalence of rheumatic manifestations in patients affected by COVID-19, as initial symptom or during disease course.

METHODS

A database search was run on May 18th, 2020, using two distinct strategies. We were interested in the percentage of symptoms of potential rheumatologic interest observed in large population studies of COVID-19 cases, and in identifying uncommon autoimmune disorders described in patients with COVID-19. For manifestations individually reported, a meta-analysis was performed taking into consideration the proportion of COVID-19 patients presenting the symptom.

RESULTS

Eighty eight original articles were included in the systematic review and 51 in the meta-analysis. We found pooled estimates of 19% for muscle pain and 32% for fatigue as initial symptom of COVID-19 presentation and, respectively, of 16 and 36% during the disease course. Only one article discussed arthralgia as unique symptom. Additionally, we found that vasculitis, chilblains, presence of autoantibodies commonly found in patients with rheumatic diseases, or autoimmune haematological and neurological disorders have all been reported in patients with COVID-19.

CONCLUSIONS

In conclusion, our review and meta-analysis emphasises that symptoms potentially leading to rheumatologic referral are common in patients with COVID-19. Therefore, COVID-19 is a new differential diagnosis to bear in mind when evaluating patients with musculoskeletal symptoms and rheumatologists might play a crucial role in identifying COVID-19 cases in early phases of the illness.

Myopathy is a Risk Factor for Poor Prognosis of Patients with Systemic Sclerosis: A retrospective cohort study

To compare clinical characteristics and identify long-term outcomes of Chinese patients with systemic sclerosis (SSc) with and without muscle involvement.We retrospectively investigated the medical records, laboratory results, and computed tomography images of 204 consecutive SSc patients. Kaplan-Meier analysis was performed to determine survival rates. Patients were allocated into groups with and without myopathy.The prevalence of myopathy was 21.6%. The myopathy group was more likely to develop diffuse cutaneous involvement (90.9% vs 56%, P = .006), interstitial lung disease (90% vs 56%, P < .001), digestive system involvement (56.7% vs 29.3%, P = .001), pulmonary hypertension (29.5% vs 10.5%, P = .004), and pericardial effusion (25% vs. 10%, P = .019). Patients with myopathy had lower single-breath diffusing capacity of the lung for carbon oxide (46.5 ± 11.1 vs 57.1 ± 13.4, P < .001).Further, the myopathy group has similar results in interstitial lung disease associated higher resolution computed tomography score (186.8 ± 64.5 vs 152.3 ± 45.5, P = .037), Valentini score for disease activity (3.4 ± 0.9 vs 2.0 ± 0.9, P < .001) and modified Rodnan total skin score (19.4 ± 6.1 vs 15.1 ± 7.7, P = .002), compared with non-myopathy group. Kaplan-Meier survival analysis revealed decreased overall survival rate of the myopathy group (P = .028).SSc Patients with myopathy had more severe clinical manifestations and higher disease activity compared with those without, which affected survival rates and indicated worse prognosis.

Thrombospondin-1 mediates muscle damage in brachio-cervical inflammatory myopathy and systemic sclerosis

Objective

To describe the clinical, serologic and histologic features of a cohort of patients with brachio-cervical inflammatory myopathy (BCIM) associated with systemic sclerosis (SSc) and unravel disease-specific pathophysiologic mechanisms occurring in these patients.

Methods

We reviewed clinical, immunologic, muscle MRI, nailfold videocapillaroscopy, muscle biopsy, and response to treatment data from 8 patients with BCIM-SSc. We compared cytokine profiles between patients with BCIM-SSc and SSc without muscle involvement and controls. We analyzed the effect of the deregulated cytokines in vitro (fibroblasts, endothelial cells, and muscle cells) and in vivo.

Results

All patients with BCIM-SSc presented with muscle weakness involving cervical and proximal muscles of the upper limbs plus Raynaud syndrome, telangiectasia and/or sclerodactilia, hypotonia of the esophagus, and interstitial lung disease. Immunosuppressive treatment stopped the progression of the disease. Muscle biopsy showed pathologic changes including the presence of necrotic fibers, fibrosis, and reduced capillary number and size. Cytokines involved in inflammation, angiogenesis, and fibrosis were deregulated. Thrombospondin-1 (TSP-1), which participates in all these 3 processes, was upregulated in patients with BCIM-SSc. In vitro, TSP-1 and serum of patients with BCIM-SSc promoted proliferation and upregulation of collagen, fibronectin, and transforming growth factor beta in fibroblasts. TSP-1 disrupted vascular network, decreased muscle differentiation, and promoted hypotrophic myotubes. In vivo, TSP-1 increased fibrotic tissue and profibrotic macrophage infiltration in the muscle.

Conclusions

Patients with SSc may present with a clinically and pathologically distinct myopathy. A prompt and correct diagnosis has important implications for treatment. Finally, TSP-1 may participate in the pathologic changes observed in muscle.

Development and validation of the Scleroderma Clinical Trials Consortium Damage Index (SCTC-DI): a novel instrument to quantify organ damage in systemic sclerosis

Objective

We sought to develop the first Damage Index (DI) in systemic sclerosis (SSc).

Methods

The conceptual definition of ‘damage’ in SSc was determined through consensus by a working group of the Scleroderma Clinical Trials Consortium (SCTC). Systematic literature review and consultation with patient partners and non-rheumatologist experts produced a list of potential items for inclusion in the DI. These steps were used to reduce the items: (1) Expert members of the SCTC (n=331) were invited to rate the appropriateness of each item for inclusion, using a web-based survey. Items with >60% consensus were retained; (2) Using a prospectively acquired Australian cohort data set of 1568 patients, the univariable relationships between the remaining items and the endpoints of mortality and morbidity (Physical Component Summary score of the Short Form 36) were analysed, and items with p<0.10 were retained; (3) using multivariable regression analysis, coefficients were used to determine a weighted score for each item. The DI was externally validated in a Canadian cohort.

Results

Ninety-three (28.1%) complete survey responses were analysed; 58 of 83 items were retained. The univariable relationships with death and/or morbidity endpoints were statistically significant for 22 items, with one additional item forced into the multivariable model by experts due to clinical importance, to create a 23-item weighted SCTC DI (SCTC-DI). The SCTC-DI was predictive of morbidity and mortality in the external cohort.

Conclusions

Through the combined use of consensus and data-driven methods, a 23-item SCTC-DI was developed and retrospectively validated.

Idiopathic inflammatory myopathies overlapping with systemic diseases

A muscle biopsy is currently requested to assess the diagnosis of an idiopathic inflammatory myopathy overlapping with a systemic disease. During the past few years, the classification of inflammatory myopathy subtypes has been revisited progressively on the basis of correlations between clinical phenotypes, autoantibodies and histological data. Several syndromic entities are now more clearly defined, and the aim of the present review is to clarify the contribution of muscle biopsy in a setting of idiopathic inflammatory myopathies overlapping with systemic diseases.
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Muscle involvement in systemic sclerosis: points to consider in clinical trials

SSc is clinically and pathogenetically heterogeneous. Consensus standards for trial design and outcome measures are needed. International experts experienced in SSc clinical trial design and a researcher experienced in systematic literature review screened the PubMed and Cochrane Central Register of Controlled Trials in order to develop points to consider when planning a clinical trial for muscle involvement in SSc. The experts conclude that SSc-associated muscle involvement is heterogeneous and lacks a universally accepted gold-standard for measuring therapeutic response. Although outcome studies are currently limited by the inability to clearly distinguish active, reversible muscle inflammation from irreversible muscle damage and extramuscular organ involvement, strong consideration should be given to enrolling patients with a myopathy that features several elements of likely reversibility such as muscle weakness, biopsy-proven active inflammation, an MRI indicating muscle inflammation and a baseline serum creatinine kinase above three times the upper limit of normal to prevent floor effect. Randomized controlled trials are preferred, with a duration of at least 24 weeks. Outcome measures should include a combination of elements that are likely to be reversible, such as muscle weakness, biopsy-proven active inflammation, creatinine kinase/aldolase and a quality of life questionnaire. The individual measurements might require a short pre-study for further validation. A biological sample repository is recommended.

Muscle function in women with systemic sclerosis: Association with fatigue and general physical function

BACKGROUND

Individuals with systemic sclerosis have muscle functions with varying degrees of muscle weakness and atrophy, which in turn can have a negative impact on functional and health-related quality of life. This study aimed to evaluate peripheral muscle performance using isokinetic dynamometry of the knee in women with systemic sclerosis and to correlate peripheral muscle dysfunction with disability levels and general fatigue.

METHODS

Twenty-six women with systemic sclerosis and a matched control group with an equal number of women underwent knee isokinetic dynamometry at angular speeds of 75°/s and 240°/s, isometric handgrip strength, the Health Assessment Questionnaire Disability Index, the Functional Assessment of Chronic Illness Therapy-Fatigue scale, and the Fatigue Impact Scale.

FINDINGS

Women with systemic sclerosis showed significant reductions in almost all isokinetic parameters for the two angular velocities tested compared with the controls. An agonist/antagonist ratio with values <40% was observed in approximately one-third of the patients. These patients had lower isometric handgrip strength. These patients also performed worse on the two general fatigue scales evaluated. Significant correlations were observed between the isokinetic parameters and the measured isometric handgrip strength, and the Health Assessment Questionnaire Disability Index.

INTERPRETATION

Systemic sclerosis patients have reduced strength and endurance as well as a muscle imbalance between the quadriceps and hamstrings. In these patients, lower muscle dysfunction of the knee joint is associated with lower handgrip strength and physical incapacity.

Early Accrual of Organ Damage in Systemic Sclerosis: Rationale for Development of a Disease Damage Index

Introduction

Systemic sclerosis (SSc) is characterized by irreversible organ damage rather than fluctuating disease activity. However, there is no validated measure of damage in SSc. We aimed to quantify the accrual of organ damage in patients with early SSc.

Methods

Patients enrolled in the Australian Scleroderma Cohort Study with less than 2 years of SSc since the onset of the first non-Raynaud's symptom were included. Organ damage was defined by a group of six experts as substantial and permanent loss of organ function due to SSc.

Results

We identified 278 patients with early SSc. Among these, 38% had diffuse SSc. Damage was more common in the diffuse than in the limited disease subtype in the skin/musculoskeletal (75% vs. 25.2%, p<0.001) and lung (31.4% vs. 19.9%, p = 0.035) domains at year seven. The rates of damage accrual were highest in the skin/musculoskeletal, gastrointestinal and respiratory systems at year two (29.1%, 18.7%, 14.4%), increasing at year five (41.4%, 30.6%, 21.2%) and declining thereafter to year seven (43.9%, 32.7%, 23.0%). In particular, there was early accrual of damage due to joint contracture (22.3%), gastrointestinal dysmotility (11.5%) and pulmonary fibrosis with forced vital capacity <70% predicted (9.7%) at year two. The highest accrual rate of organ-specific damage from years two to seven was seen in fecal incontinence followed by proximal muscle weakness and pulmonary fibrosis.

Conclusions

Substantial accrual of organ damage occurs early in the course of disease, particularly in diffuse SSc. This provides the rationale for the development of a SSc damage index.

Systemic sclerosis: Association between physical function, handgrip strength and pulmonary function

BACKGROUND

Systemic sclerosis (SSc) is a multisystem disease affecting the skin, respiratory system and skeletal muscles. In SSc patients, hand function disability is the major factor limiting daily activities.

AIM

To evaluate the association of physical function with handgrip strength and pulmonary function in SSc patients. A further aim was to assess the relationship between handgrip strength and pulmonary function in patients with SSc.

METHOD

A cross-sectional study in which 28 patients with SSc underwent isometric handgrip strength (IHGS) measurement and pulmonary function tests and completed the Health Assessment Questionnaire Disability Index (HAQ-DI) to measure physical function.

RESULTS

The HAQ-DI scores were associated with the IHGS (r_s = -0.599, P = 0.001) and pulmonary function parameters, particularly the diffusion capacity for carbon monoxide (DLco; r_s = -0.642, P = 0.0004).

CONCLUSION

In patients with SSc, the degree of physical disability is associated with both hand grip strength and pulmonary function. However, there is no relationship between handgrip strength and pulmonary function in these patients.

Inflammatory myopathies: A new landscape

Greater accuracy in clinical descriptions combined with advances in muscle histology and immunology have established that inflammatory myopathies (IMs), similarly to inflammatory rheumatic diseases, constitute a highly heterogeneous group of conditions. The topographic distribution, severity, and tempo of onset of the myopathy vary widely, and the histological findings distinguish at least five different profiles, which may reflect different pathophysiological processes. Most IMs are connective tissue diseases that can affect multiple organs, among which the most common targets are the skin, joints, and lungs. The extramuscular manifestations may antedate the muscular involvement and should therefore suggest a diagnosis of IM even in the absence of obvious muscle disease. About 20 different autoantibodies have been identified in patients with IM. Some are mutually exclusive and associated with specific combinations of clinical manifestations. Following the model of antisynthetase syndrome, about 10 syndromes associated with autoantibodies specific of IM have been identified. Thus, polymyositis is now emerging as a rare entity that is often mistaken for more recently described patterns of IM. No consensus exists to date about the classification of IMs. Nevertheless, the clinical manifestations, autoantibody profile, and muscle histology can be used to distinguish patient subgroups with fairly homogeneous patterns of complications, treatment responses, and outcomes. These subgroups are also characterized by specific genetic and environmental factors. The advances made in the nosology of IMs have benefited the diagnosis, personalization of treatment strategies, and understanding of pathophysiological mechanisms. They can be expected to assist in the development of specific treatments.

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.

Independent Association of Severity of Muscle Weakness With Disability as Measured by the Health Assessment Questionnaire Disability Index in Scleroderma

OBJECTIVE

To determine whether the presence and degree of muscle weakness in scleroderma is associated with disability.

METHODS

The study included a cohort of 1,718 scleroderma patients who had available data on muscle strength and disability. The primary independent variable was muscle weakness as defined by the maximum Medsger muscle severity score and the outcome was disability as measured by the last recorded Health Assessment Questionnaire disability index (HAQ DI) score. Univariate regression analyses were performed to assess the association of HAQ DI scores with the Medsger muscle severity score and other scleroderma characteristics. A multivariate regression analysis was performed to determine whether an association existed between the degree of muscle weakness and disability, while controlling for confounders.

RESULTS

In 1,718 patients with scleroderma, 22.8% (392 of 1,718) had muscle weakness, as defined by a Medsger muscle severity score of ≥1. This subset was more likely than those without weakness to have diffuse cutaneous scleroderma (55.6% versus 35.1%; P < 0.0001), higher modified Rodnan skin thickness scores (mean ± SD 16.3 ± 13.7 versus 10.3 ± 10.6; P < 0.00001), shorter disease duration (mean ± SD 5.21 ± 6.75 versus 6.22 ± 7.67 years; P = 0.02), synovitis (17.7% versus 11.4%; P = 0.001), forced vital capacity <70% (46.2% versus 30.6%; P = 0.0001), and higher creatine kinase values (mean ± SD 441 ± 1,211 versus 151 ± 255; P = 0.00001). Both univariate and multivariate analyses revealed that for every unit of increase in the Medsger muscle severity score, there was a clinically significant (minimum clinically important difference ± 0.14) increase in the mean HAQ DI score at last followup visit.

CONCLUSION

The presence of muscle weakness associates with several features of worse disease burden and independently associates with disability as measured by the HAQ DI.

Patients with Systemic Sclerosis/polymyositis Overlap Have a Worse Survival Rate Than Patients Without It

OBJECTIVE

Studies on mortality associated with patients with systemic sclerosis (SSc) and myopathy have been limited by heterogeneous definitions of muscle involvement. The objective of this study is to determine whether homogeneous-defined SSc/polymyositis overlap (SSc-PM overlap) is associated with a worse survival rate compared with SSc without PM.

METHODS

Data from the Nijmegen Systemic Sclerosis cohort were used. Incidence rates were calculated from the observed number of deaths and followup time. Survival analysis using Cox proportional hazard modeling was performed to compare survival among patients with SSc and patients with SSc-PM overlap, including controlling for confounders. All patients with SSc-PM fulfilled the Bohan and Peter criteria for PM.

RESULTS

There were 24 patients with SSc-PM (5.7%) and 396 patients with SSc (94.2%). The 5- and 10-year cumulative survival rates from diagnosis were 82% and 68% for the SSc-PM group and 93% and 87% for the SSc group, respectively. Multivariate survival analysis revealed an adjusted HR of 2.34 (95% CI 1.09-5.02) for SSc-PM compared with SSc, with age at diagnosis, modified Rodnan skin score, diffuse cutaneous subtype, and male sex included as confounders. The most common cause of death among patients with SSc-PM overlap was cardiopulmonary involvement (63%), which was similar to the patients with SSc (51%).

CONCLUSION

Patients with SSc-PM overlap have a worse survival rate compared with patients with SSc.

Spectrum of Muscle Histopathologic Findings in Forty-Two Scleroderma Patients With Weakness

OBJECTIVE

To determine if distinct muscle pathologic features exist in scleroderma subjects with weakness.

METHODS

This retrospective study included weak scleroderma subjects with muscle biopsies available for review. Biopsies were systematically assessed for individual pathologic features, including inflammation, necrosis, fibrosis, and acute neurogenic atrophy. Based on the aggregate individual features, biopsies were assigned a histopathologic category of polymyositis, dermatomyositis, necrotizing myopathy, nonspecific myositis, "acute denervation," "fibrosis only," or "other." Clinical data analyzed included autoantibody profiles, scleroderma subtype and disease duration, Medsger muscle severity scores, creatine kinase, electromyography, and muscle magnetic resonance imaging.

RESULTS

A total of 42 subjects (79% female and 64% diffuse scleroderma) were included in this study. Necrosis (67%), inflammation (48%), acute neurogenic atrophy (48%), and fibrosis (33%) were the most prevalent pathologic features. The presence of fibrosis was strongly associated with anti-PM-Scl antibodies. Histopathologic categories included nonspecific myositis (36%), necrotizing myopathy (21%), dermatomyositis (7%), "acute denervation" (7%), "fibrosis only" (7%), and polymyositis (5%). Disease duration of scleroderma at the time of muscle biopsy was shorter in polymyositis than other histopathologic categories. Patients with anti-PM-Scl and Scl-70 antibodies also had a shorter disease duration than those with other autoantibody profiles.

CONCLUSION

Nonspecific myositis and necrotizing myopathy were the most common histopathologic categories in weak scleroderma subjects. Surprisingly, nearly half of the subjects studied had histologic evidence of acute motor denervation (acute neurogenic atrophy); this has not been previously reported. Taken together, these observations suggest that a variety of pathologic mechanisms may underlie the development of myopathy in scleroderma.