Composite measures to assess disease damage, disease severity and treatment response in systemic sclerosis clinical trials

PURPOSE OF REVIEW

The aim of this study was to summarize the composite outcome measures available to assess disease damage, severity and treatment response in systemic sclerosis (SSc).

RECENT FINDINGS

There have been many recent efforts to rigorously develop and validate composite outcome measures to assess the totality of the impact of SSc on patients. All initiatives have used both consensus and data-driven methods. Recently developed are a SSc-specific damage index, a patient-reported disease impact questionnaire (ScleroID) and a treatment response index (ACR-CRISS).

SUMMARY

Multiorgan, composite measures are being increasingly applied to assess treatment efficacy in clinical trials. Although a fully validated, disease-specific composite measure is not yet available, there has been significant recent progress towards developing measures of treatment response, damage and overall impact of SSc for application in randomized controlled trials.

Sudden cardiac death, arrhythmias and abnormal electrocardiography in systemic sclerosis: A systematic review and meta-analysis

OBJECTIVE

To calculate the frequency of sudden cardiac death(SCD), arrhythmia and conduction defects in SSc.

METHODS

MEDLINE/EMBASE were searched to January 2023. English-language studies reporting the incidence/frequency of SCD, arrhythmia and electrocardiography(ECG) abnormalities in SSc were included. Odds ratios(OR), estimations of annual incidence or pooled frequencies were calculated.

RESULTS

Seventy-nine studies(n = 13,609 participants with SSc) were included in the meta-analysis. Methodology and outcomes were heterogeneous. Ten studies included cohorts with known/suspected SSc-associated heart involvement(SHI), generally defined as clinically-manifest cardiac disease/abnormal cardiac investigations. The incidence of SCD in SHI was estimated to be 3.3% annually(n = 4 studies, 301PY follow-up). On ambulatory ECG, 18% of SHI cohorts had non-sustained ventricular tachycardia(NSVT; n = 4, 95%CI3.2-39.3%), 70% frequent premature ventricular complexes (PVCs; n = 1, 95%CI34.8-93.3%), and 8% atrial fibrillation (AF; n = 1, 95%CI4.2-13.6%). Nineteen studies included participants without SHI, defined as normal cardiac investigations/absence of cardiac disease. The estimated incidence of SCD was approximately 2.9% annually (n = 1, 67.5PY). Compared to healthy controls, individuals without SHI demonstrated NSVT 13.3-times more frequently (n = 2, 95%CI2-102), and paroxysmal supraventricular tachycardia 7-times more frequently (n = 4, 95%CI3-15). Other ambulatory ECG abnormalities included NSVT in 9% (n = 7, 95%CI6-14%), >1000 PVCs/24 h in 6% (n = 2, 95%CI1-13%), and AF in 7% (n = 5, 0-21%). Fifty studies included general SSc cohorts unselected for cardiac disease. The incidence of SCD was estimated to be 2.0% annually(n = 4 studies, 1646PY). Unselected SSc cohorts were 10.5-times more likely to demonstrate frequent PVCs (n = 2, 95%CI 2-59) and 2.5-times more likely to have an abnormal electrocardiography (n = 2, 95%CI1-4).

CONCLUSIONS

The incidence of SCD in SSc is estimated to be 1.0-3.3% annually, at least 10-fold higher than general population estimates. Arrhythmias including NSVT and frequent PVCs appear common, including amongst those without known/suspected SHI.

Multidisciplinary team discussion: the emerging gold standard for management of cardiopulmonary complications of connective tissue disease

Cardiopulmonary complications of connective tissue diseases (CTDs), particularly pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD), are major determinants of morbidity and mortality. Multidisciplinary meetings may improve diagnostic accuracy and optimise treatment. We review the literature regarding multidisciplinary meetings in CTD-ILD and PAH and describe our tertiary centre experience of the role of the multidisciplinary meeting in managing CTD-PAH.

Paternal genome elimination: patterns and mechanisms of drive and silencing

In thousands of arthropod species, males inherit, but subsequently eliminate the entire haploid genome of their father. However, why this peculiar reproductive strategy evolved repeatedly across diverse species and what mechanisms are involved in paternal genome elimination (PGE) remains largely unknown. In this review, we summarize what we know about the patterns of paternal chromosome elimination during various stages of development in the diverse taxa that have been studied. We also discuss some other unusual features often associated with PGE, such as the transcriptional silencing of paternally derived chromosomes in males and sex determination through the early embryonic elimination of X chromosomes. Little is known about the molecular mechanisms underlying the parent-of-origin-dependent chromosome elimination and silencing under PGE, but we discuss the insight of several studies that are pioneering this work and highlight directions for future research.

The genome sequence of the springtail Allacma fusca (Linnaeus, 1758)

We present a genome assembly from an individual male Allacma fusca (the springtail; Arthropoda; Collembola; Symphypleona; Sminthuridae). The genome sequence is 392.8 megabases in span. Most of the assembly is scaffolded into 6 chromosomal pseudomolecules, including the X 1 and X 2 sex chromosomes. The mitochondrial genome has also been assembled and is 14.94 kilobases in length.

Are asymmetric inheritance systems an evolutionary trap? Transitions in the mechanism of paternal genome loss in the scale insect family Eriococcidae

Haplodiploidy and paternal genome elimination (PGE) are examples of asymmetric inheritance, where males transmit only maternally inherited chromosomes to their offspring. Under haplodiploidy, this results from males being haploid, whereas under PGE, males inherit but subsequently exclude paternally inherited chromosomes from sperm. Their evolution involves changes in the mechanisms of meiosis and sex determination and sometimes also dosage compensation. As a result, these systems are thought to be an evolutionary trap, meaning that once asymmetric chromosome transmission evolves, it is difficult to transition back to typical Mendelian transmission. We assess whether there is evidence for this idea in the scale insect family Eriococcidae, a lineage with PGE and the only clade with a suggestion that asymmetric inheritance has transitioned back to Mendelian inheritance. We conduct a cytological survey of 13 eriococcid species, and a cytological, genetic, and gene expression analysis of species in the genus Cystococcus, to investigate whether there is evidence for species in this family evolving Mendelian chromosome transmission. Although we find that all species we examined exhibit PGE, the mechanism is extremely variable within Eriococcidae. Within Cystococcus, in fact, we uncover a previously undiscovered type of PGE in scale insects that acts exclusively in meiosis, where paternally inherited chromosomes in males are present, uncondensed, and expressed in somatic cells but eliminated prior to meiosis. Broadly, we fail to find evidence for a reversion from PGE to Mendelian inheritance in Eriococcidae, supporting the idea that asymmetric inheritance systems such as PGE may be an evolutionary trap.

Recent evolution of a maternally-acting sex-determining supergene in a fly with single-sex broods

Sex determination is a key developmental process, yet it is remarkably variable across the tree of life. The dipteran family Sciaridae exhibits one of the most unusual sex determination systems in which mothers control offspring sex through selective elimination of paternal X chromosomes. Whereas in some members of the family females produce mixed-sex broods, others such as the dark-winged fungus gnat Bradysia coprophila are monogenic, with females producing single-sex broods. Female-producing females were previously found to be heterozygous for a large X-linked paracentric inversion (X´), which is maternally inherited and absent from male-producing females. Here we assembled and characterized the X´ sequence. As close sequence homology between the X and X´ made identification of the inversion challenging, we developed a k-mer-based approach to bin genomic reads before assembly. We confirmed that the inversion spans most of the X´ chromosome (approximately 55Mb) and encodes around 3500 genes. Analysis of the divergence between the inversion and the homologous region of the X revealed that it originated very recently (<0.5 mya). Surprisingly, we found that the X´ is more complex than previously thought and is likely to have undergone multiple rearrangements that have produced regions of varying ages, resembling a supergene composed of evolutionary strata. We found functional degradation of around 7.3% of genes within the region of recombination suppression, but no evidence of accumulation of repetitive elements. Our findings provide an indication that sex-linked inversions are driving turnover of the strange sex determination system in this family of flies.

Why put all your eggs in one basket? Evolutionary perspectives on the origins of monogenic reproduction

Sexual reproduction is ubiquitous in eukaryotes, but the mechanisms by which sex is determined are diverse and undergo rapid turnovers in short evolutionary timescales. Usually, an embryo's sex is fated at the moment of fertilisation, but in rare instances it is the maternal genotype that determines the offspring's sex. These systems are often characterised by mothers producing single-sex broods, a phenomenon known as monogeny. Monogenic reproduction is well documented in Hymenoptera (ants, bees and wasps), where it is associated with a eusocial lifestyle. However, it is also known to occur in three families in Diptera (true flies): Sciaridae, Cecidomyiidae and Calliphoridae. Here we review current knowledge of monogenic reproduction in these dipteran clades. We discuss how this strange reproductive strategy might evolve, and we consider the potential contributions of inbreeding, sex ratio distorters, and polygenic control of the sex ratio. Finally, we provide suggestions on future work to elucidate the origins of this unusual reproductive strategy. We propose that studying these systems will contribute to our understanding of the evolution and turnover of sex determination systems.

CATCH-UP vaccines: protocol for a randomized controlled trial using the multiphase optimization strategy (MOST) framework to evaluate education interventions to increase COVID-19 vaccine uptake in Oklahoma

BACKGROUND

Oklahoma's cumulative COVID-19 incidence is higher in rural than urban counties and higher than the overall US incidence. Furthermore, fewer Oklahomans have received at least one COVID-19 vaccine compared to the US average. Our goal is to conduct a randomized controlled trial using the multiphase optimization strategy (MOST) to test multiple educational interventions to improve uptake of COVID-19 vaccination among underserved populations in Oklahoma.

METHODS

Our study uses the preparation and optimization phases of the MOST framework. We conduct focus groups among community partners and community members previously involved in hosting COVID-19 testing events to inform intervention design (preparation). In a randomized clinical trial, we test three interventions to improve vaccination uptake: (1) process improvement (text messages); (2) barrier elicitation and reduction (electronic survey with tailored questions/prompts); and (2) teachable moment messaging (motivational interviewing) in a three-factor fully crossed factorial design (optimization).

DISCUSSION

Because of Oklahoma's higher COVID-19 impact and lower vaccine uptake, identifying community-driven interventions is critical to address vaccine hesitancy. The MOST framework provides an innovative and timely opportunity to efficiently evaluate multiple educational interventions in a single study.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT05236270, First Posted: February 11, 2022, Last Update Posted: August 31, 2022.

Clinical characteristics and survival of pulmonary arterial hypertension with or without interstitial lung disease in systemic sclerosis

OBJECTIVES

To describe the clinical phenotype and prognosis of people in the Australian Scleroderma (SSc) Cohort Study with pulmonary arterial hypertension (PAH) with or without interstitial lung disease (ILD).

METHODS

Participants meeting ACR/EULAR criteria for SSc were divided into four mutually exclusive groups: those meeting criteria for PAH (PAH-only), ILD (ILD-only), concurrent PAH and ILD (PAH-ILD) or neither PAH nor ILD (SSc-only). Logistic or linear regression analyses were used for associations between clinical features, health-related quality of life (HRQoL) and physical function. Survival analysis was performed using Kaplan-Meier estimates and Cox-regression modelling.

RESULTS

Of 1561 participants, 7% fulfilled criteria for PAH-only, 24% ILD-only, 7% PAH-ILD and 62% SSc-only. People with PAH-ILD were more frequently male, with diffuse skin involvement, higher inflammatory markers, older age of SSc onset and higher frequency of extensive ILD than the cohort overall (p < 0.001). People of Asian race more frequently developed PAH-ILD (p < 0.001). People with PAH-ILD or PAH-only had worse WHO functional class and 6-min-walk-distance than ILD-only (p < 0.001). HRQoL scores were worst in those with PAH-ILD (p < 0.001). Survival was reduced in the PAH-only and PAH-ILD groups (p < 0.01). Multivariable hazard modelling demonstrated the worst prognosis in extensive ILD and PAH (HR = 5.65 95% CI 3.50-9.12 p < 0.01), followed by PAH-only (HR = 4.21 95% CI 2.89-6.13 p < 0.01) and PAH with limited ILD (HR = 2.46 95% CI 1.52-3.99 p < 0.01).

CONCLUSIONS

The prevalence of concurrent PAH-ILD in the ASCS is 7%, with poorer survival in those patients with PAH-ILD compared to ILD or SSc alone. The presence of PAH confers a poorer overall prognosis than even extensive ILD; however, further data are required to better understand the clinical outcomes of this high-risk patient group.

DNA methylation is associated with codon degeneracy in a species of bumblebee

Social insects display extreme phenotypic differences between sexes and castes even though the underlying genome can be almost identical. Epigenetic processes have been proposed as a possible mechanism for mediating these phenotypic differences. Using whole genome bisulfite sequencing of queens, males, and reproductive female workers we have characterised the sex- and caste-specific methylome of the bumblebee Bombus terrestris. We have identified a potential role for DNA methylation in histone modification processes which may influence sex and caste phenotypic differences. We also find differentially methylated genes generally show low levels of DNA methylation which may suggest a separate function for lowly methylated genes in mediating transcriptional plasticity, unlike highly methylated genes which are usually involved in housekeeping functions. We also examined the relationship between the underlying genome and the methylome using whole genome re-sequencing of the same queens and males. We find DNA methylation is enriched at zero-fold degenerate sites. We suggest DNA methylation may be acting as a targeted mutagen at these sites, providing substrate for selection via non-synonymous changes in the underlying genome. However, we did not see any relationship between DNA methylation and rates of positive selection in our samples. In order to fully assess a possible role for DNA methylation in adaptive processes a specifically designed study using natural population data is needed.

Sex-specific transcription and DNA methylation landscapes of the Asian citrus psyllid, a vector of huanglongbing pathogens

The relationship of DNA methylation and sex-biased gene expression is of high interest, it allows research into mechanisms of sexual dimorphism and the development of potential novel strategies for insect pest control. The Asian citrus psyllid, Diaphorina citri Kuwayama, is a major vector for the causative agents of Huanglongbing (HLB), which presents an unparalleled challenge to citrus production worldwide. Here, we identify the X chromosome of D. citri and investigate differences in the transcription and DNA methylation landscapes between adult virgin males and females. We find a large number of male-biased genes on the autosomes and a depletion of such on the X chromosome. We have also characterised the methylome of D. citri, finding low genome-wide levels, which is unusual for an hemipteran species, as well as evidence for both promoter and TE methylation. Overall, DNA methylation profiles are similar between the sexes but with a small number of differentially methylated genes found to be involved in sex differentiation. There also appears to be no direct relationship between differential DNA methylation and differential gene expression. Our findings lay the groundwork for the development of novel epigenetic-based pest control methods, and given the similarity of theD. citri methylome to some other insect species, these methods could be applicable across agricultural insect pests.

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.

Muscle biopsy practices in the evaluation of neuromuscular disease: A systematic literature review

AIMS

Muscle biopsy techniques range from needle muscle biopsy (NMB) and conchotome biopsy to open surgical biopsy. It is unknown whether specific biopsy techniques offer superior diagnostic yield or differ in procedural complication rates. Therefore, we aimed to compare the diagnostic utility of NMB, conchotome and open muscle biopsies in the assessment of neuromuscular disorders.

METHODS

A systematic literature review of the EMBASE and Medline (Ovid) databases was performed to identify original, full-length research articles that described the muscle biopsy technique used to diagnose neuromuscular disease in both adult and paediatric patient populations. Studies of any design, excluding case reports, were eligible for inclusion. Data pertaining to biopsy technique, biopsy yield and procedural complications were extracted.

RESULTS

Sixty-four studies reporting the yield of a specific muscle biopsy technique and, or procedural complications were identified. Open surgical biopsies provided a larger tissue sample than any type of percutaneous muscle biopsy. Where anaesthetic details were reported, general anaesthesia was required in 60% of studies that reported open surgical biopsies. Percutaneous biopsies were most commonly performed under local anaesthesia and despite the smaller tissue yield, moderate- to large-gauge needle and conchotome muscle biopsies had an equivalent diagnostic utility to that of open surgical muscle biopsy. All types of muscle biopsy procedures were well tolerated with few adverse events and no scarring complications were reported with percutaneous sampling.

CONCLUSIONS

When a histological diagnosis of myopathy is required, moderate- to large-gauge NMB and the conchotome technique appear to have an equivalent diagnostic yield to that of an open surgical biopsy.

The Multidisciplinary Heart Team in Cardiovascular Medicine: Current Role and Future Challenges

Cardiovascular multidisciplinary heart teams (MDHTs) have evolved significantly over the past decade. These teams play a central role in the treatment of a wide array of cardiovascular diseases affecting interventional cardiology, cardiac surgery, interventional imaging, advanced heart failure, adult congenital heart disease, cardio-oncology, and cardio-obstetrics. To meet the specific needs of both patients and heart programs, the composition and function of cardiovascular MDHTs have had to adapt and evolve. Although lessons have been learned from multidisciplinary cancer care, best practices for the operation of cardiovascular MDHTs have yet to be defined, and the evidence base supporting their effectiveness is limited. This expert panel review discusses the history and evolution of cardiovascular MDHTs, their composition and role in treating patients across a broad spectrum of disciplines, basic tenets for successful operation, and the future challenges facing them.

Evaluation of patient and physician assessments of gastrointestinal disease activity in systemic sclerosis

Objective

To assess whether patient and physician global assessment of gastrointestinal disease in systemic sclerosis (SSc) are associated with a meaningful change in disease status.

Methods

One hundred and forty-three participants from the Australian Scleroderma Cohort Study were recruited to this study. Using logistic regression analysis, we evaluated the relationship between patient and physician assessed gastrointestinal disease status and symptoms, measures of health-related quality of life (Medical Short Form 36 (SF-36)) and gastrointestinal disease severity, measured by the Scleroderma Clinical Trials Consortium (SCTC) UCLA Gastrointestinal Tract 2.0 Score (GIT 2.0).

Results

Patient-reported worsening of gastrointestinal symptoms in the month preceding assessment was significantly associated with more severe gastrointestinal disease (OR 6.14, p<0.01) and progressive worsening gastrointestinal disease severity as measured by the GIT 2.0 score (OR 45.98, p<0.01). The new onset of reflux was the only specific symptom associated with patient reported gastrointestinal disease activity (OR 2.98, p=0.04). Physician assessed gastrointestinal disease activity was not significantly associated with higher GIT 2.0 scores or increasing severity of disease. Patient and physician assessed gastrointestinal activity was not associated with SF-36 scores.

Conclusion

In the absence of objective measures of gastrointestinal disease activity in SSc, patient-reported symptoms of gastrointestinal disease could be used to indicate disease activity and merit consideration for inclusion in a multi-system disease activity index.

Patient and Physician Global Assessments of Disease Status in Systemic Sclerosis

Global assessments of disease by both patients and physicians are widely used in clinical studies of systemic sclerosis (SSc). They are commonly secondary end points in randomized controlled trials (RCTs) and are considered important items in composite measures of treatment response. A comprehensive literature review was conducted of the formats, wording, and clinimetric properties of the patient global assessment of disease status (PtGA) and physician global assessment of disease status (PhGA) used in RCTs of SSc. Marked heterogeneity was found in the wording and measurement scales of the global assessments applied in RCTs. These instruments were not developed using rigorous methodology and have not been fully validated. There is a pressing need for standardization and validation of patient and physician global assessment tools in SSc to enable universal application of these measures across RCTs in SSc.

The clinical implications of left ventricular diastolic dysfunction in systemic sclerosis

OBJECTIVES

We sought to quantify the burden of left ventricular diastolic dysfunction (LVDD) and heart failure with preserved ejection fraction (HFpEF) in systemic sclerosis (SSc) and assess the progression of LVDD over time and its prognostic importance.

METHODS

Two-hundred and twenty-five participants enrolled in the Australian Scleroderma Cohort Study were included and LVDD was assessed according to 2016 ASE/EACVI Guidelines. Logistic regression analyses and generalised estimating equations were performed to evaluate the relationship between LVDD and SSc disease characteristics and symptoms and signs of heart failure, respectively. The relationship between LVDD and mortality was assessed using Kaplan-Meier survival estimates.

RESULTS

Thirty-four (15%) participants were diagnosed with LVDD. A further 89 (40%) participants had indeterminate diastolic function. Older age (p<0.01), hypertension (p=0.02), impaired systolic function (p=0.03) and interstitial lung disease (p=0.01) were all associated with the presence of LVDD. There was no association between the presence of LVDD and clinical signs of heart failure, however, LVDD was associated with more breathlessness and worse functional class (p=0.03). LVDD was observed to progress over time, with significant worsening of parameters of left ventricular filling pressure. There was no significant relationship between LVDD and mortality (p=0.23).

CONCLUSIONS

Abnormal diastolic function is a common finding in SSc, progresses over time and is associated with more severe dyspnoea. Whilst patients with LVDD are more breathless, LVDD is not clearly associated with clinical findings of heart failure demonstrating that LVDD may be of importance in explaining symptoms even in the absence of HFpEF in SSc.

Overall survival in the OlympiA phase III trial of adjuvant olaparib in patients with germline pathogenic variants in BRCA1/2 and high risk, early breast cancer

BACKGROUND

The randomized, double-blind OlympiA trial compared 1 year of the oral poly(adenosine diphosphate-ribose) polymerase inhibitor, olaparib, to matching placebo as adjuvant therapy for patients with pathogenic or likely pathogenic variants in germline BRCA1 or BRCA2 (gBRCA1/2pv) and high-risk, human epidermal growth factor receptor 2-negative, early breast cancer (EBC). The first pre-specified interim analysis (IA) previously demonstrated statistically significant improvement in invasive disease-free survival (IDFS) and distant disease-free survival (DDFS). The olaparib group had fewer deaths than the placebo group, but the difference did not reach statistical significance for overall survival (OS). We now report the pre-specified second IA of OS with updates of IDFS, DDFS, and safety.

PATIENTS AND METHODS

One thousand eight hundred and thirty-six patients were randomly assigned to olaparib or placebo following (neo)adjuvant chemotherapy, surgery, and radiation therapy if indicated. Endocrine therapy was given concurrently with study medication for hormone receptor-positive cancers. Statistical significance for OS at this IA required P < 0.015.

RESULTS

With a median follow-up of 3.5 years, the second IA of OS demonstrated significant improvement in the olaparib group relative to the placebo group [hazard ratio 0.68; 98.5% confidence interval (CI) 0.47-0.97; P = 0.009]. Four-year OS was 89.8% in the olaparib group and 86.4% in the placebo group (Δ 3.4%, 95% CI -0.1% to 6.8%). Four-year IDFS for the olaparib group versus placebo group was 82.7% versus 75.4% (Δ 7.3%, 95% CI 3.0% to 11.5%) and 4-year DDFS was 86.5% versus 79.1% (Δ 7.4%, 95% CI 3.6% to 11.3%), respectively. Subset analyses for OS, IDFS, and DDFS demonstrated benefit across major subgroups. No new safety signals were identified including no new cases of acute myeloid leukemia or myelodysplastic syndrome.

CONCLUSION

With 3.5 years of median follow-up, OlympiA demonstrates statistically significant improvement in OS with adjuvant olaparib compared with placebo for gBRCA1/2pv-associated EBC and maintained improvements in the previously reported, statistically significant endpoints of IDFS and DDFS with no new safety signals.

Genomic evidence of paternal genome elimination in the globular springtail Allacma fusca

Paternal genome elimination (PGE) - a type of reproduction in which males inherit but fail to pass on their father's genome - evolved independently in six to eight arthropod clades. Thousands of species, including several important for agriculture, reproduce via this mode of reproduction. While PGE is well established in some of the clades, the evidence in globular springtails (Symphypleona) remains elusive, even though they represent the oldest and most species rich clade putatively reproducing via PGE. We sequenced genomic DNA from whole bodies of Allacma fusca males with high fractions (>27.5%) of sperm to conclusively confirm that all the sperm carry one parental haplotype only. Although it is suggestive that the single haplotype present in sperm is maternally inherited, definitive genetic proof of the parent of origin is still needed. The genomic approach we developed allows for detection of genotypic differences between germline and soma in all species with sufficiently high fraction of germline in their bodies. This opens new opportunities for scans of reproductive modes in small organisms.

Gene-rich X chromosomes implicate intragenomic conflict in the evolution of bizarre genetic systems

Haplodiploidy and paternal genome elimination (HD/PGE) are common in invertebrates, having evolved at least two dozen times, all from male heterogamety (i.e., systems with X chromosomes). However, why X chromosomes are important for the evolution of HD/PGE remains debated. The Haploid Viability Hypothesis posits that X-linked genes promote the evolution of male haploidy by facilitating purging recessive deleterious mutations. The Intragenomic Conflict Hypothesis holds that conflict between genes drives genetic system turnover; under this model, X-linked genes could promote the evolution of male haploidy due to conflicts with autosomes over sex ratios and genetic transmission. We studied lineages where we can distinguish these hypotheses: species with germline PGE that retain an XX/X0 sex determination system (gPGE+X). Because evolving PGE in these cases involves changes in transmission without increases in male hemizygosity, a high degree of X linkage in these systems is predicted by the Intragenomic Conflict Hypothesis but not the Haploid Viability Hypothesis. To quantify the degree of X linkage, we sequenced and compared 7 gPGE+X species’ genomes with 11 related species with typical XX/XY or XX/X0 genetic systems, representing three transitions to gPGE. We find highly increased X linkage in both modern and ancestral genomes of gPGE+X species compared to non-gPGE relatives and recover a significant positive correlation between percent X linkage and the evolution of gPGE. These empirical results substantiate longstanding proposals for a role for intragenomic conflict in the evolution of genetic systems such as HD/PGE.

POS0888 NON-SURGICAL LOCAL TREATMENTS FOR DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Digital ulcers(DUs) in systemic sclerosis(SSc) represent a major clinical challenge. There are no recommendations for the local management of SSc-DUs. Systemic therapy is considered the standard of care. However, there is a strong rationale for local approaches to DU by avoiding side effects from systemic therapies. The World Scleroderma Foundation DU Working Group intends to develop evidence-based recommendations for DU management including local, non-surgical treatment(ln-sT).

Objectives

To summarise the literature on the safety and efficacy of ln-sT for SSc-DUs.

Methods

A systematic literature review(SLR) of papers describing the use of ln-sT for DU in SSc was performed up to May 2021 according to the PICO framework. References were independently screened by two reviewers who independently assessed the full text of eligible articles and extracted data.

Results

Among 790 retrieved references, 12 were included. Median(range) number of patients per study was 9(7–84), mean age ranging from 37 to 62.5 years. In 5(41%) studies a control group was included. Background systemic therapies are summarized in Table 1. The most studied treatment was botulin toxin A(BTA). It was used as hand injection in 3 studies (median dose ranging from 90 to 150 U) and as 50 U single finger injection in 1 study. Healing rate after a median time of 8-49 weeks ranged from 71% to 100%. In 2 studies a reduction in VAS pain was observed from 20% to 100%. Transient muscle weakness was the most common side effect in 10% of patients. Amniotic(Am) and hydrocolloid membranes(HyM) were used in 1 study each. They were associated with a good healing rate, statistically significant for the HyM. Tadalafil 2% cream was studied in 1 study and was associated with a reduction in the median DU number from 1.6 to 1 per patient after a median time of 4 weeks and a reduction by 1.4 point in the 10-mm VAS scale. Vitamin E gel was shown to be associated with a statistically significant reduction in the healing time compared to SoC alone in 1 RCT(13.2 ± 2.7 versus 20.9 ± 3.6 weeks, P=<0.001). Low-level light therapy, hydrodissection and corticosteroid injection and extracorporeal shock wave(ESW) were evaluated in 1 study each. They were all associated with positive outcomes which was statistically significant only for the ESW. The only negative trial examined dimethyl sulfoxide and was associated with local toxicity.

Table 1.

Characteristics of the studies.

TreatmentType of studyPatientsBaseline DUBackground therapy (%) ETA CCB APA PG ARB ACE-I PDE-5i ISFollow-up (weeks)Healing rate(%)*Pain Reduction (VAS/10)ComparatorHydrodissection and corticosteroid injectionP1202334.4Rheumatoid ArthritisTadalafil 2% Vitamin E gelRRCT15131.6(1)3.5±2.30462700130704 241(1)Reduced time to heal**1.4SoCAmHyMRP67310001002800002817033143810090**SoCBTAMedian 90 U per handHigh-concentration hand100 U non-dominant handSingle finger 50 URRPP772010314571140718558551008514201001414718 4981277717510020%100%Untreated CHLow-level light therapyP8102537025378100ESWP9493355661144441**1.31Dimethyl sulfoxideDBRCT84No change, skin toxicity with 70% formulation

*Unless otherwise stated. **Statistically significant. ARB= angiotensin receptor antagonist. ACEi= ACE inhibitors. APA= anti-platelet agents. CCB= calcium channel blockers. CH= contralateral hand. DBRCT= double blind randomized-controlled trial. ETA = endothelin antagonist. IS= immunosuppression. PG= prostaglandins. PDE-5i= Phosphodiesterase type-5 inhibitors. P = prospective. R = retrospective. SoC= standard of care (as per local protocol).

Conclusion

Our SLR supports interest to develop ln-sTs for SSc-DUs. The number of studies is limited and mainly case reports and small single studies are present. Treatments were well tolerated and there was evidence of efficacy for BTA, vitamin E, ESW and HyM in refractory DUs. The evidence is not robust and confounding factors (vasodilators background therapies) could impact on the findings. Future research is indicated to conduct larger, well-designed studies.

Disclosure of Interests

Corrado Campochiaro: None declared, Yossra A. Suliman: None declared, Michael Hughes Speakers bureau: Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work., Jan Schoones: None declared, Dilia Giuggioli: None declared, Pia Moinzadeh Speakers bureau: speaking fees from Actelion pharmaceuticals and Boehringer Ingelheim, Nancy Maltez: None declared, Laura Ross: None declared, Murray Baron: None declared, Lorinda Chung: None declared, Yannick Allanore: None declared, Christopher P Denton: None declared, Oliver Distler Speakers bureau: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur, Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Speakers bureau: Janssen and Eicos Sciences, Inc., Thomas Krieg: None declared, Masataka Kuwana Speakers bureau: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

POS0898 SURGICAL MANAGEMENT OF DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Management of digital ulcers (DUs) in systemic sclerosis (SSc) is a major clinical challenge. To date, systemic therapy is generally considered as the ‘standard of care’ for significant SSc-DUs. However, there is a strong rationale to develop local approaches to DUs, to avoid side effects from systemic therapies. World Scleroderma Foundation DU Working Group intends to develop practical, evidence-based recommendations for DU management including local, Surgical Treatment (L-ST).

Objectives

To summarize the literature on the safety and efficacy of L-ST for SSc-DUs.

Methods

A systematic literature review (SLR) was conducted up to May 2021. According to the PICO framework, eligibility criteria were defined and original research articles about surgical treatment of SSc DUs in adult patients were included. References were independently screened by 2 reviewers who assessed the full text of eligible articles and extracted data.

Results

Thirteen eligible articles out of 790 total publications were identified (Table 1). Due to the paucity of randomized controlled trials of surgical treatments for SSc-DU, we included retrospective studies and case series with at least 4 patients. Autologous fat (adipose tissue AT) grafting was the surgical modality mostly identified (7 studies of which 1 RCT and 6 prospective open label single arm). The healing rate (HR) with autologous fat grafting (4 studies) ranged from 66-100 %. In the RCT, two age and sex matched groups were included, adipose tissue (AT)group (n=25 pts) and sham procedure (SP) group (n=13), DU healing was reported in 23/25 in AT group versus 1/13 in the SP group in 8 wks, (p<0.0001), 12 pts in the SP group, received rescue AT injection, all of them healed after 8 wks. Three studies reported autologous adipose-derived stromal vascular fraction(SVF) grafting and the HR ranged from 32-60%, followed up to 12 months. Transient edema and paresthesia were reported in 2 studies, and amputation in 2 ulcers in 1 study, and no complications were reported in other studies. Surgical sympathectomy was reported in 3 studies, with a median healing rate of 81%. Bone marrow derived cell transplantation in a single study showed 87% healing rate over (4-24 wks). Two surgical studies (of direct microsurgical revascularization N=4, and microsurgical arteriolysis, N=6), showed 100% healing of ulcers, no complications reported.

Table 1.

Characteristics of the extracted studies.

StudydesignPatients (n)Baseline DU (n)Background therapy (%)Follow-upOutcomeHealed ulcers(%) Adipose tissue graftAutologous fat graftp9.15PG, CCB—100ETA 26PDE-5i 138-12 wks66Adipose tissue graftingRCT25 case13- Ctr25-case13- CtrPG- 100CCB 1008 wks92-case7-CtrAdipose tissue implantp1515no therapy7 wks100Adipose tissue graftp129PG,CCB-100ETA6 month88adipose derived SVFp1215PDE-5i, ccb, PG allowed22m6Adipose derived SVFp1215CCB 50ETA166 m63 Adipose derived SVFp1819CCB 50PG 27ETA 5IS 7124 wks32SympathectomySympathectomyR611CCB-10020 m81SympathectomyR1335PGCCBAPA35Sympathectomy, vascular bypass (+vein graftR1726Ccb 35APA 47PDE-i5 589 m100Bone marrow derived cells transplantation)p88PG-6236 m87Direct microsurgical revascularizationR44m100Limited microsurgical arteriolysisR61712 m100

SVF =stromal vascular fraction P = prospective. R = retrospective. RCT= double blind randomized-controlled trial. ETA = endothelin antagonist. CCB= calcium channel blockers. APA= anti-platelet agents. PG= prostaglandins. ARB= angiotensin receptor antagonist. ACEi= ACE inhibitors. PDE-5i= PDE-5 inhibitors. IS= immunosuppression. M=median. SoC= standard of care. HR= healing rate

Conclusion

Our SLR has identified several surgical modalities for SSc-DUs. L-STseemed generally effective and safe for DU healing, thus Significant methodological issues emerged including small numbers of pts, lack of comparator, failure to report confounders such as background therapies and variable follow up. Future research is warranted to rigorously investigate surgical interventions for Dus.

Disclosure of Interests

Yossra A. Suliman: None declared, Corrado Campochiaro: None declared, Michael Hughes Speakers bureau: speaking fees from Actelion pharmaceuticals, Eli Lilly, and Pfizer, outside of the submitted work, Jan Schoones: None declared, Dilia Giuggioli: None declared, Nancy Maltez: None declared, Pia Moinzadeh Speakers bureau:: speaking fees from Actelion pharmaceuticals and Boehringer Ingelheim, Laura Ross: None declared, Lorinda Chung: None declared, Yannick Allanore: None declared, Murray Baron: None declared, Christopher P Denton: None declared, Oliver Distler Shareholder of: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Speakers bureau: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Consultant of: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Grant/research support from: Consultancy relationship with and/or has received research funding from and/or has served as a speaker for the following companies in the area of potential treatments for systemic sclerosis and its complications in the last three calendar years: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur. Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143)., Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Speakers bureau: Janssen and Eicos Sciences, Inc., Paid instructor for: Janssen and Eicos Sciences, Inc., Consultant of: Janssen and Eicos Sciences, Inc., Thomas Krieg: None declared, Masataka KUWANA Speakers bureau: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Paid instructor for: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Consultant of: Speakers fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and Consultant fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida, outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

POS0900 SYSTEMIC PHARMACOLOGICAL TREATMENT OF DIGITAL ULCERS IN SYSTEMIC SCLEROSIS: A SYSTEMATIC LITERATURE REVIEW

Background

Digital ulcers (DU) are common in systemic sclerosis (SSc) and associated with reduced survival, high morbidity and poor quality of life. Recommendations have previously been proposed for DU management yet there remains significant unmet patient need. Therefore the World Scleroderma Foundation DU Working Group intends to develop practical evidence based recommendations for DU management.

Objectives

To summarise data on efficacy and safety of systemic treatments for SSc DU.

Methods

A systematic literature review to May 2021 was performed. PubMed, MEDLINE, Embase, Web of Science, Cochrane Library, Emcare (OVID) and Academic Search Premier databases were searched for original studies on adult patients with SSc DU treated with systemic pharmacological treatment. Based on the PICO framework, eligibility criteria were defined and references were independently screened by two reviewers. Reviewers independently assessed the full text of eligible articles. Owing to interstudy heterogeneity narrative summaries were used to present data.

Results

The search strategy identified 1271 references of which 45 eligible articles were included. Seventeen studies were randomised placebo controlled trials (RCT) pertaining to PDE5 antagonists (PDE5i) (n=3), endothelin receptor antagonists (ERA) (n=3), prostanoids (n=7), antiplatelet agents (n=1) and other (n=3) (Table 1). No head to head RCT was retrieved. All other studies were observational studies (OBS). Studies were highly heterogeneous with application of differing definition of DU, variable study eligibility criteria, clinical endpoints and follow up periods. This limited the calculation of effect size and comparison across studies.

Table 1.

Characteristics of placebo controlled randomised controlled trials

Author YearInterventionnFollow upOutcomeFavours interventionHachulla 2016Sildenafil8312 weeksTime to DU healing-Andrigueti 2017Sildenafil4112 weeksDU healing+Shenoy 2010Tadalafil246 weeksNew DU+Khanna 2016Macitentan55416 weeksNew DU-Matucci-Cerinic 2011Bosentan18832 weeksNew DU Time to healing of DU+-Korn 2004Bosentan12212 weeksNew DU+Kawald 2008IV iloprost5012 monthsDU healing-Wigley 1992IV iloprost3510 weeksDU healing+Wigley 1994IV iloprost739 weeks50% reduction in DU score-Seibold 2017Treprostinil14820 weeksNet DU burden-Vayssairat 1999Beraprost10725 weeks% patients with new DU-Denton 2017Selexipag7412 weeksNumber of new DU DU healing-Lau 1993Cicaprost334 weeksNumber of DU-Abou-Raya 2008Atorvastatin844 monthsNumber of DU+Au 2010Cyclophosphamide15812 monthsNumber of patients with DU-Beckett 1984Dipyridamole / aspirin412 yearsChange in general SSc-Nagaraja 2019Riociguat1732 weeksNet DU burden-

+ significantly superior to comparator

- non significantly different from comparator

DU: digital ulcers IV: intravenous SSc: systemic sclerosis

Several RCT found improved DU healing with treatment: two with PDE5i, one with iloprost and one showed improved DU healing and prevention with atorvastatin. Two RCT demonstrated effective prevention of new DU with bosentan. OBS studies with a total of 621 patients showed variable improvements in the healing of DU with CCB, PDE5i, ERA, statins, N-acetylcysteine, prostanoids and ketanserin and prevention of new DU with ERA.

Regarding safety, all treatments were generally tolerated with few serious adverse events. Treatment was ceased in 6.25-17.5% of patients in RCT due to treatment related side effects.

Conclusion

Despite several studies assessing the efficacy and safety of systemic pharmacological treatment of SSc DU, it is not possible to draw solid conclusions due to study heterogeneity. Small RCT have shown treatment benefit with PDE5i, iloprost and atorvastatin. Large studies demonstrated effective prevention of new DU with bosentan. Our results highlight the urgent need for improved clinical trial design to generate more robust evidence and novel therapies to guide the management SSc DU.

Acknowledgements

This work was supported by the World Scleroderma Foundation.

Disclosure of Interests

Nancy Maltez: None declared, Laura Ross: None declared, Michael Hughes Speakers bureau: Actelion Pharmaceuticals, Eli Lilly and Pfizer outside of the submitted work., Jan Schoones: None declared, Murray Baron: None declared, Lorinda Chung Consultant of: Eicos, Corrado Campochiaro: None declared, Yossra A. Suliman: None declared, Dilia Giuggioli: None declared, Pia Moinzadeh Speakers bureau: Actelion Pharmaceuticals, Boehringer Ingelheim, Yannick Allanore: None declared, Christopher P Denton: None declared, Oliver Distler Speakers bureau: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Consultant of: Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Grant/research support from: Patent issued “mir-29 for the treatment of systemic sclerosis” (US8247389, EP2331143), Abbvie, Acceleron, Alcimed, Amgen, AnaMar, Arxx, AstraZeneca, Baecon, Blade, Bayer, Boehringer Ingelheim, Corbus, CSL Behring, Galapagos, Glenmark, Horizon, Inventiva, Kymera, Lupin, Medscape, Miltenyi Biotec, Mitsubishi Tanabe, MSD, Novartis, Prometheus, Roivant, Sanofi and Topadur., Tracy Frech: None declared, Daniel Furst: None declared, Dinesh Khanna Consultant of: Eicos Sciences Inc, Janssen, Thomas Krieg: None declared, Masataka Kuwana Speakers bureau: Speaker fees from AbbVie, Asahi Kasei Pharma, Astellas, Boehringer Ingelheim, Chugai, Eisai, GlaxoSmithKline, Janssen, Nippon Shinyaku, Ono Pharmaceuticals, Tanabe-Mitsubishi, and consultancy fees from AstraZeneca, Boehringer Ingelheim, Corbus, Kissei, Mochida outside of the submitted work., Marco Matucci-Cerinic: None declared, Janet Pope: None declared, Alessia Alunno: None declared

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.