Validation of manual muscle testing and a subset of eight muscles for adult and juvenile idiopathic inflammatory myopathies

Patient global assessment and inflammatory markers in patients with idiopathic inflammatory myopathies - A longitudinal study

AIM

To explore if patient global assessment (PGA) is associated with inflammation over time and if associations are explained by other measures of disease activity and function in patients with idiopathic inflammatory myopathies (IIM).

METHODS

PGA and systemic inflammatory markers prospectively collected over five years were retrieved from the International MyoNet registry for 1200 patients with IIM. Associations between PGA, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and creatine kinase (CK) were analyzed using mixed models. Mediation analysis was used to test if the association between PGA and inflammatory markers during the first year of observation could be explained by measures of disease activity and function.

RESULTS

PGA improved, and inflammatory markers decreased during the first year of observation. In the mixed models, high levels of inflammatory markers were associated with worse PGA in both men and women across time points during five years of observation. In men, but not in women, the association between elevated ESR, CRP and poorer PGA was explained by measures of function and disease activity. With a few exceptions, the association between improved PGA and reduced inflammatory markers was partially mediated by improvements in all measures of function and disease activity.

CONCLUSION

Increased levels of systemic inflammation are associated with poorer PGA in patients with IIM. In addition to known benefits of lowered inflammation, these findings emphasize the need to reduce systemic inflammation to improve subjective health in patients with IIM. Furthermore, the results demonstrate the importance of incorporating PGA as an outcome measure in clinical practice and clinical trials.

Artificial intelligence for nailfold capillaroscopy analyses - a proof of concept application in juvenile dermatomyositis

BACKGROUND

Biomarkers for idiopathic inflammatory myopathies are difficult to identify and may involve expensive laboratory tests. We assess the potential for artificial intelligence (AI) to differentiate children with juvenile dermatomyositis (JDM) from healthy controls using nailfold capillaroscopy (NFC) images. We also assessed the potential of NFC images to reflect the range of disease activity with JDM.

METHODS

A total of 1,120 NFC images from 111 children with active JDM, diagnosed between 1990 and 2020, and 321 NFC images from 31 healthy controls were retrieved from the CureJM JDM Registry. We built a lightweight and explainable deep neural network model called NFC-Net. Images were downscaled by interpolation techniques to reduce the computational cost.

RESULTS

NFC-Net achieved high performance in differentiating patients with JDM from controls, with an area under the ROC curve (AUROC) of 0.93 (0.84, 0.99) and accuracy of 0.91 (0.82, 0.92). With sensitivity (0.85) and specificity (0.90) resulted in model precision of 0.95. The AUROC and accuracy for predicting clinical disease activity from inactivity were 0.75 (0.61, 0.81) and 0.74 (0.65, 0.79).

CONCLUSION

The good performance of the NFC-Net demonstrates that NFC images are sufficient for detecting often unrecognized JDM disease activity, providing a reliable indicator of disease status.

IMPACT

Proposed NFC-Net can accurately predict children with JDM from healthy controls using nailfold capillaroscopy (NFC) images. Additionally, it predicts the scores to JDM disease activity versus no activity. Equipped with gradients, NFC-Net is explainable and gives visual information beside the reported accuracies. NFC-Net is computationally efficient since it is applied to substantially downscaled NFC images. Furthermore, the model can be wrapped within an edge-based device like a mobile application that is accessible to both clinicians and patients.

Fatty infiltration in the posterior muscles of the lower extremities as an MRI feature in antimitochondrial antibody-associated myopathy

OBJECTIVE

Idiopathic inflammatory myopathy (IIM) with antimitochondrial M2 antibody (AMA-M2) has been associated with distinct clinical characteristics. In this study, we explore the magnetic resonance imaging (MRI) findings of the muscles of the lower extremities in AMA-M2-positive IIM to gain more insight.

METHODS

MRI of 22 lower extremity muscles was retrospectively evaluated in 14 patients with AMA-M2-positive IIM and 37 age- and sex-matched patients with AMA-M2-negative IIM. Muscles with inflammatory edema and fatty infiltration were assessed according to the Stramare and Mercuri criteria.

RESULTS

Patients with AMA-M2-positive IIM had significantly higher incidence of MRI involvement with fatty infiltration in five lower extremity muscles, namely the adductor magnus (AM) (13/14 VS 14/37, p < 0.001), semimembranosus (SM) (13/14 VS 17/37, p = 0.002), biceps femoris (BF) (12/14 VS 15/37, p = 0.004), soleus (13/14 VS 23/37, p = 0.041), and the medial head of the gastrocnemius (Gastroc M) (13/14 VS 17/37, p = 0.002) than patients with AMA-M2-negative IIM. Furthermore, the severity scores of fatty infiltrations of the above five muscles in AMA-M2-positive IIM were significantly higher than those in patients with AMA-M2-negative IIM (p < 0.001).

CONCLUSIONS

Severe fatty infiltrations of the AM, SM, BF, soleus, and Gastroc M in the posterior muscles of the lower extremities are dominant MRI features in our patients with AMA-M2-positive IIM. This unique muscle MRI character may be a helpful indicator in clinical practice for patients with AMA-M2-positive IIM. Key Points • Striking involvement and prominent fatty infiltrations of five lower extremity muscles (adductor magnus, semimembranosus, biceps femoris, soleus, and the medial head of the gastrocnemius) are interesting MRI performances. • Severe fatty infiltrations in the posterior muscles of the lower extremities are dominant MRI features in AMA-M2-positive IIM. • This unique muscle MRI character may be very helpful for the diagnosis of the AMA-M2-positive IIM.

CD19 CAR T-Cell Therapy in Autoimmune Disease - A Case Series with Follow-up

BACKGROUND

Treatment for autoimmune diseases such as systemic lupus erythematosus (SLE), idiopathic inflammatory myositis, and systemic sclerosis often involves long-term immune suppression. Resetting aberrant autoimmunity in these diseases through deep depletion of B cells is a potential strategy for achieving sustained drug-free remission.

METHODS

We evaluated 15 patients with severe SLE (8 patients), idiopathic inflammatory myositis (3 patients), or systemic sclerosis (4 patients) who received a single infusion of CD19 chimeric antigen receptor (CAR) T cells after preconditioning with fludarabine and cyclophosphamide. Efficacy up to 2 years after CAR T-cell infusion was assessed by means of Definition of Remission in SLE (DORIS) remission criteria, American College of Rheumatology-European League against Rheumatism (ACR-EULAR) major clinical response, and the score on the European Scleroderma Trials and Research Group (EUSTAR) activity index (with higher scores indicating greater disease activity), among others. Safety variables, including cytokine release syndrome and infections, were recorded.

RESULTS

The median follow-up was 15 months (range, 4 to 29). The mean (±SD) duration of B-cell aplasia was 112±47 days. All the patients with SLE had DORIS remission, all the patients with idiopathic inflammatory myositis had an ACR-EULAR major clinical response, and all the patients with systemic sclerosis had a decrease in the score on the EUSTAR activity index. Immunosuppressive therapy was completely stopped in all the patients. Grade 1 cytokine release syndrome occurred in 10 patients. One patient each had grade 2 cytokine release syndrome, grade 1 immune effector cell-associated neurotoxicity syndrome, and pneumonia that resulted in hospitalization.

CONCLUSIONS

In this case series, CD19 CAR T-cell transfer appeared to be feasible, safe, and efficacious in three different autoimmune diseases, providing rationale for further controlled clinical trials. (Funded by Deutsche Forschungsgemeinschaft and others.).

Interferon type I signature associated with skin disease in juvenile dermatomyositis

Background

Interferon type I (IFN-I) signaling system hyperactivation plays an important role in the pathogenesis of juvenile dermatomyositis (JDM).

Aim of the study

To analyze IFN-I score with disease activity in patients with JDM.

Materials and methods

Clinical manifestations laboratory data, and treatment options were analyzed in 15 children with JDM. Disease activity was assessed by CMAS (childhood myositis assessment tool) and CAT (cutaneous assessment tool) scores. IFN I-score was assessed by RT-PCR quantitation of 5 IFN I-regulated transcripts (IFI44L, IFI44, IFIT3, LY6E, MXA1).

Results

All patients had skin and muscle involvement, some had a fever (n = 8), swallowing disorders (n = 4), arthritis (n = 5), calcinosis (n = 3), lipodystrophy (n = 2), and interstitial lung disease (n = 5). Twelve patients had elevated IFN I-score and it was correlated with skin disease activity. Ten patients had clinically active disease and the level of IFN I-score and its components were higher than in patients with inactive disease (8.8 vs. 4.2, p = 0.011). IFN I-score was evaluated in nine patients during follow-up. The simultaneous reduction of IFN I-score and its components, CMAS and CAT scores was observed.

Conclusion

Skin involvement in refractory JDM is a challenging problem requiring the use of additional medications. Serum IFN I-score might be suggested as the promising biomarker of skin disease activity in JDM patients. Further investigations on patients with JDM and recurrent disease activity are needed, especially concerning biomarkers that determine the response to JAK inhibitors and treatment options for patients who don't respond to them.

Immune-Mediated Necrotizing Myopathy (IMNM): A Story of Antibodies

Immune-mediated necrotizing myopathy (IMNM) is a rare and severe disease that corresponds to a specific entity of idiopathic inflammatory myopathy. Patients with IMNM suffer from proximal muscle weakness, and present high levels of creatine kinase and necrotic myofibers. Anti-Signal Recognition Particle (SRP) and anti-3-hydroxy-3-methylglutaryl-coenzyme A reductase autoantibodies (HMGCR) have recently been identified in two thirds of patients with IMNM and are used as a hallmark of the disease. In this review, we provide a detailed description of these antibodies and the tests used to detect them in the serum of patients. Based on in vitro studies and mouse models of IMNM, we discuss the role of autoantibodies in the pathogenesis of the disease. Finally, in the light of the latest knowledge, we conclude with a review of recent therapeutic approaches in IMNM.

Defining criteria for disease activity states in juvenile dermatomyositis based on the Juvenile Dermatomyositis Activity Index

OBJECTIVES

To develop and validate the cut-offs in the Juvenile DermatoMyositis Activity Index (JDMAI) to distinguish the states of inactive disease (ID), low disease activity (LDA), moderate disease activity (MDA) and high disease activity (HDA) in children with juvenile dermatomyositis (JDM).

METHODS

For cut-off definition, data from 139 patients included in a randomised clinical trial were used. Among the six versions of the JDMAI, JDMA1 (score range 0-40) and JDMAI2 (score range 0-39) were selected. Optimal cut-offs were determined against external criteria by calculating different percentiles of score distribution and through receiver operating characteristic curve analysis. External criteria included the modified Pediatric Rheumatology International Trials Organization (PRINTO) criteria for clinically ID in JDM (for ID) and PRINTO levels of improvement in the clinical trial (for LDA and HDA). MDA cut-offs were set at the score interval between LDA and HDA cut-offs. Cut-off validation was conducted by assessing construct and discriminative ability in two cohorts including a total of 488 JDM patients.

RESULTS

The calculated JDMAI1 cut-offs were ≤2.4 for ID, ≤6.6 for LDA, 6.7-11 for MDA and >11 for HDA. The calculated JDMAI2 cut-offs were ≤5.2 for ID, ≤8.5 for LDA, 8.6-11.3 for MDA and >11.3 for HDA. The cut-offs discriminated strongly among disease activity states defined subjectively by caring physicians and parents, parents' satisfaction or non-satisfaction with illness outcome, levels of pain, fatigue, physical functional impairment and physical well-being.

CONCLUSIONS

Both JDMAI1 and JDMAI2 cut-offs revealed good metrologic properties in validation analyses and are, therefore, suited for application in clinical practice and research.

Increased expression of the p-STAT3/IL-17 signaling pathway in patients with dermatomyositis

OBJECTIVES

The aim is to explore the roles of phosphorylated signal transduction and activator of transcription 3 (p-STAT3) and interleukin (IL)-17 in patients with dermatomyositis (DM).

METHODS

A total of 20 DM patients and 12 healthy controls were enrolled. Flow cytometry combined with counting was used to detect the number of Th17 cells. Western blotting and immunohistochemistry were used to examine the muscle levels of p-STAT3 and IL-17, and serum levels of IL-17 were measured by enzyme-linked immunosorbent assays.

RESULTS

Muscle p-STAT3 and IL-17 levels, the number of Th17 cells, and serum IL-17 levels were markedly increased in DM. p-STAT3 and IL-17 were co-expressed in the muscle of DM patients. The p-STAT3 levels were correlated with the number of Th17 cells as well as muscle and serum IL-17 levels. The correlations of the p-STAT3 level with elevated levels of transaminases, myocardial enzymes, and the health assessment questionnaire score were significantly positive, while the correlation with manual muscle testing-8 was significantly negative. A receiver operating characteristic curve indicated the good predictive value of p-STAT3 for the occurrence of DM.

CONCLUSIONS

The increased p-STAT3/IL-17 signaling pathway activation in DM patients may induce muscle inflammation and necrosis, and it may be a potential target for DM.

YKL-40 serum levels are predicted by inflammatory state, age and diagnosis of idiopathic inflammatory myopathies

YKL-40 increase according to the aging process, and its functions have been associated with tissue remodeling and systemic inflammation. In Rheumatoid Arthritis (RA) it has been proposed as a possible biomarker of activity and severity, however; in the field of idiopathic inflammatory myopathies (IIM) the role of YKL-40 in IIM is not clear. Thus, we aimed to evaluate if there is an association between the serum levels and muscle tissue expression of YKL-40 with age, IIM phenotype, muscle strength and myositis disease activity. The main finding was that age is the most important variable that affects the YKL-40 serum levels. In muscle biopsy, we observed that YKL-40 is mainly expressed in infiltrating lymphoid cells than in muscle tissue. Using ANCOVA according to the b-coefficients, YKL-40 serum levels are predicted by inflammatory state, age, and IIM diagnosis.

TWEAK and Fn14 are overexpressed in immune-mediated necrotizing myopathy: implications for muscle damage and repair

OBJECTIVES

TNF-like weak inducer of apoptosis (TWEAK) and its sole receptor fibroblast growth factor-inducible 14 (Fn14) are involved in various inflammatory conditions. This study was performed to investigate the potential role of TWEAK/Fn14 in immune-mediated necrotizing myopathy (IMNM).

METHODS

Muscle biopsies from patients with IMNM (n = 37) and controls (n = 11) were collected. Human muscle cells were treated with TWEAK in vitro. Muscle biopsies and cultured muscle cells were analysed by immunostaining and quantitative PCR. Serum levels of TWEAK and Fn14 were detected by ELISA.

RESULTS

TWEAK and Fn14 were overexpressed in IMNM muscle biopsies. The percentage of Fn14-positive myofibers correlated with disease severity, myonecrosis, regeneration and inflammation infiltrates. Fn14-positive myofibers tended to be surrounded or invaded by CD68+ macrophages. TWEAK treatment had a harmful effect on cultured muscle cells by inducing the production of multiple chemokines and pro-inflammatory cytokines. Serum Fn14 levels were increased in patients with IMNM and correlated with muscle weakness.

CONCLUSIONS

TWEAK/Fn14 signalling was activated in IMNM, most likely aggravating muscle damage via amplifying inflammatory response and macrophages chemotaxis. Fn14 seems to be a biomarker for assessing disease severity in IMNM. In addition, Fn14 may also contribute to muscle injury repair.

Skeletal muscle injury in COVID infection: Frequency and patterns

INTRODUCTION/AIMS

Little is known about skeletal muscle injury with coronavirus disease 2019 (COVID-19). We estimate the frequency and explore the patterns of skeletal muscle injury in acute COVID-19.

METHODS

A cohort of COVID patients with mild to moderate symptoms were evaluated in a COVID-designated hospital between May and December 2021 and followed for 2 weeks. Skeletal muscle injury was assessed according to creatine kinase (CK) levels, Manual Muscle Test-8 (MMT-8) score, and the Health Assessment Questionnaire (HAQ) score. Injury was defined as CK >200 IU/L with an MMT-8 score < 76. The association between such injury and severity and outcomes were evaluated using cross-tabulations.

RESULTS

Two hundred fifty participants with a mean age of 50.2 years (SD: 17.2) were included. One hundred nine (43.6%) were women; 84 (34%) developed severe disease. Median CK levels were 91 IU/L (IQR 56-181). [Correction added on 17 November 2023, after first online publication: In the preceding sentence, the IQR was corrected from '56,181'.] Patients with weakness on the MMT-8 (n = 247, 98.8%) and disability on the HAQ (n = 107; 42.8%) were common. Neck flexor muscles were prominently affected. Skeletal muscle injury was seen in 22.4% (95% CI: 17.4-28.1). There was no significant association between skeletal muscle injury and maximal severity of illness or short-term outcomes. Disability increased over 14 days in most survivors (n = 172, 72.3%) and this was not seen in those with mild disease (OR: 0.4, 95% CI: 0.22-0.70).

DISCUSSION

Skeletal muscle injury appears to be common in people presenting with mild to moderate COVID infection.

Complications of peroneus longus tendon harvesting: a retrospective review of 82 cases

OBJECTIVE

Peroneus longus tendon (PLT) has become a reliable autologous graft option for various ligament reconstructions. But there are potential risks and complications associated with its use as a graft. This retrospective study aimed to examine the complications and donor site morbidity following PLT harvesting.

PATIENTS AND METHODS

A retrospective review was performed on an institutional digital patient database, and all patients who underwent ligament reconstruction using PLT autograft were identified. Intraoperative, early, and late complications were reviewed using digital patient notes and patients underwent a complete physical examination during their final follow-up. Ankle function was assessed using the AOFAS score, and manual ankle muscle testing was performed on both sides. Sural nerve iatrogenic injury was evaluated with a dermatomal light touch examination. Cosmetic satisfaction due to incision scar and footwear complaints were also assessed.

RESULTS

82 patients (74 male, eight female) with a mean age of 31.9 ± 10.4 years (range, 16-66) were included in the final analysis. The mean follow-up time was 46.6 ± 30.3 months (range, 6-109). The mean AOFAS score for the donor side was 98.7 ± 3.3 (range, 87-100), and the contralateral side score was 100, with manual muscle testing graded as 5 in all movements and similar to the contralateral side. Fifteen patients (18.3%) had hypoesthesia over the dorsolateral aspect of the foot distal to the incision scar, two patients (2.4%) had hyperalgesia over the distal incision scar, and one patient (1.2%) had mild ankle instability. There were two cases (2.4%) of compartment syndrome, both of which were treated with fasciotomy and had complete regression of symptoms after 5 days. One patient (1.2%) had a transient peroneal nerve injury and foot drop that resolved in the sixth month.

CONCLUSIONS

The results of this retrospective study suggest that harvesting the PLT is associated with a high rate of complications and donor site morbidity. The most common complication was hypoesthesia around the lateral side of the foot, although the ankle functions were not affected significantly. Two cases of compartment syndrome and one transient peroneal nerve injury were observed. Care should be taken while harvesting PLT autograft, and it should be kept in mind that peroneal nerve injury might occur.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Reduced bone mineral density in patients with idiopathic inflammatory myopathies: a case-control study

Background

Patients with idiopathic inflammatory myopathies (IIMs) are at risk of reduced bone mineral density (BMD).

Objectives

To compare the prevalence of reduced BMD between patients with IIMs and controls and to determine its risk factors.

Design

This was a single-center case-control study.

Methods

BMD was assessed by dual-energy X-ray absorptiometry. The prevalence of reduced BMD in IIM patients and age-and sex-matched non-rheumatological controls was compared. The BMD results of female IIM were also compared to age-matched female rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients. Independent factors associated with reduced BMD in IIM patients were identified by multivariate analyses.

Results

A total of 230 patients (IIM: 65, non-rheumatological controls: 65, RA: 50, SLE: 50) were recruited. The mean age of IIM patients was 58.6 ± 11.0 years and 76.9% were females. Significantly, more IIM patients had reduced BMD (73.8% versus 43.1%, p = 0.043) and osteoporosis (29.2% versus 13.8%, p = 0.033) than non-rheumatological controls. Multivariate analysis confirmed that IIM was independently associated with reduced BMD (OR: 2.12, p = 0.048, 95% CI: 1.01-4.46). The prevalence of reduced BMD was not significantly different between IIM, RA, and SLE patients but the mean hip BMD was the lowest in the IIM group (0.641 ± 0.152 g/cm²versus 0.663 ± 0.102g/cm² in the RA group versus 0.708 ± 0.132 g/cm² in the SLE group, p = 0.035). Lower body mass index and more advanced age were independently associated with lower BMD in IIM patients.

Conclusion

Reduced BMD was more prevalent in IIM patients than in non-rheumatological controls. Hip BMD was lower in patients with IIMs than RA or SLE. Close monitoring and early treatment are encouraged especially in patients with risk factors.

Currently recommended skin scores correlate highly in the assessment of patients with Juvenile Dermatomyositis (JDM)

BACKGROUND

Juvenile Dermatomyositis (JDM) is a rare, chronic, and life-threatening childhood autoimmune disease. Currently, there are recommended, reliable and validated measurement tools for assessment of skin disease activity in JDM including the Disease Activity Score (skinDAS), Cutaneous Assessment Tool (CAT), and the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). The Physician's global assessment skin visual analog scale (Skin VAS) is also widely used for skin activity in JDM. For the purpose of comparative international studies, we wanted to compare these tools to the Physician's skin VAS (as a standard) to identify which performs better.

OBJECTIVES

We sought to compare the correlations of these scoring tools, and separately assess the responsiveness each tool demonstrates following patient treatment, in order to see if one tool may be preferred. This was determined by assessing how well these tools correlate with each other, and the Physician's skin VAS over time, as well as the responsiveness of each tool after patient treatment.

METHODS

Skin scores were recorded at a baseline (first visit after June 1^st, 2018) and all follow-up office visits at the Juvenile Dermatomyositis Clinic. Following baseline visits, patients were followed up as clinically indicated. A subset of newly diagnosed patients (inception cohort) was identified. Correlations were assessed at the baseline visit and over time for the whole cohort. The correlations over time were derived using Generalized Estimating Equations (GEEs). Standardized response means with 95% confidence intervals were calculated to test score responsiveness for the nested inception cohort.

RESULTS

The skinDAS, CAT and CDASI all correlated highly with each other and with the Physician's skin VAS. The three scoring tools accurately reflected Physician's skin VAS scores over time. In addition, all tools showed moderate to high responsiveness following treatment.

CONCLUSION

All studied skin score tools performed well in our study and appear to be useful. Since no tool far outperforms the others, arbitrary consensus will be needed to select a single standard measurement tool for the purposes of efficiency and global comparability.

First-line immunosuppression in neuromuscular diseases

Autoimmune neuromuscular diseases are common and often treatable causes for peripheral nervous system dysfunction. If not optimally managed, they result in meaningful impairments and disability. The treating neurologist should aim to maximise clinical recovery with minimal iatrogenic risk. This requires careful patient and medication selection, appropriate counselling and close monitoring of clinical efficacy and safety. Here, we summarise our consensus departmental approach to first-line immunosuppression in neuromuscular diseases. We combine multispecialty evidence and expertise with a focus on autoimmune neuromuscular diseases to create guidance on starting, dosing and monitoring for toxic effects of the commonly used drugs. These include corticosteroids, steroid-sparing agents and cyclophosphamide. We also provide efficacy monitoring advice, as clinical response informs dosage and drug choice. The principles of this approach could be applied across much of the spectrum of immune-mediated neurological disorders where there is significant therapeutic crossover.

A machine learning analysis to evaluate the outcome measures in inflammatory myopathies

OBJECTIVE

To assess the long-term outcome in patients with Inflammatory Idiopathic Myopathies (IIM), focusing on damage and activity disease indexes using artificial intelligence (AI).

BACKGROUND

IIM are a group of rare diseases characterized by involvement of different organs in addition to the musculoskeletal. Machine Learning analyses large amounts of information, using different algorithms, decision-making processes, self-learning neural networks.

METHODS

We evaluate the long-term outcome of 103 patients with IIM, diagnosed on 2017 EULAR/ACR criteria. We considered different parameters, including clinical manifestations and organ involvement, number and type of treatments, serum creatine kinase levels, muscle strength (MMT8 score), disease activity (MITAX score), disability (HAQ-DI score), disease damage (MDI score), and physician and patient global assessment (PGA). The data collected were analysed, applying, with R, supervised ML algorithms such as lasso, ridge, elastic net, classification, and regression trees (CART), random forest and support vector machines (SVM) to find the factors that best predict disease outcome.

RESULTS AND CONCLUSION

Using artificial intelligence algorithms we identified the parameters that best correlate with the disease outcome in IIM. The best result was on MMT8 at follow-up, predicted by a CART regression tree algorithm. MITAX was predicted based on clinical features such as the presence of RP-ILD and skin involvement. A good predictive capacity was also demonstrated on damage scores: MDI and HAQ-DI. In the future Machine Learning will allow us to identify the strengths or weaknesses of the composite disease activity and damage scores, to validate new criteria or to implement classification criteria.

Transcranial direct current electrical stimulation in combination with aerobic exercise: A pilot study in post-COVID-19 systemic autoimmune rheumatic patients

BACKGROUND

Systemic autoimmune rheumatic diseases (SARDs) are a group of diseases with multiorgan involvement and a high prevalence of chronic pain and fatigue. Patients with SARDs and post-coronavirus disease 2019 (COVID-19) syndrome experience aggravation of symptoms. In this context, it is essential to establish strategies to reduce chronic pain and fatigue and improve quality of life.

AIM

To assess the efficacy of transcranial direct current stimulation (tDCS) for the treatment of fatigue and pain-associated post-COVID-19 syndrome in patients with SARDs.

METHODS

This study included nine patients with different types of SARDs. All patients had reverse transcription-polymerase chain reaction (RT-PCR) test confirmed COVID-19 as well as significant, persistent fatigue and pain that began to worsen after infection. Anodal tDCS was administered in five daily sessions (2mA, 20 min). Concomitantly, patients were involved in aerobic exercise program. All participants were evaluated using specific questionnaires and strength assessment by handgrip and physical function by timed-up-and-go test and sit-to-stand test at baseline (within one week before tDCS protocol), and one week after tDCS protocol. During all procedures, the patients’ treatments remained unchanged.

RESULTS

The sample comprised eight women and one man with a mean age of 48.7 ± 9.6 years. After the tDCS protocol, pain and fatigue significantly improved on the visual analog scale (P < 0.05). The physical function also improved 9.5 ± 2.7 vs 6.8 ± 0.8 (P = 0.001) for timed-up-go-test and 10.3 ± 3.7 vs 15.1 ± 4.0 (P = 0.037) for sit-to-stand test. None of the patients experienced any adverse events.

CONCLUSION

The present study showed that tDCS in combination with aerobic exercise was effective in improving physical function, and reducing fatigue/pain in SARDs patients with post-COVID-19 syndrome.

Immunosuppressive and immunomodulatory therapies for idiopathic inflammatory myopathies

This is a protocol for a Cochrane Review (intervention). The objectives are as follows:

This protocol is for two separate reviews to assess the effects (benefits and harms) of immunosuppressant and immunomodulatory treatments for the idiopathic inflammatory myopathies.  

Musculoskeletal and Gait Characteristics in Patients with Stickler Syndrome: A Cross-Sectional Study

BACKGROUND

Stickler syndrome (SS) is a connective tissue disorder of fibrillary collagen with very variable clinical manifestations, including premature osteoarthritis and osteopenia. This musculoskeletal alteration may affect gait maturity or produce strength difficulties.

OBJECTIVE

Our aim was to describe the musculoskeletal characteristics, bone stiffness, gait kinematics, and kinetics of SS patients.

METHODS

This is a cross-sectional study of children and youngsters with SS recruited by telephone calls through the Spanish SS Association. All participants underwent an analysis of musculoskeletal characteristics, including a 3D gait analysis.

RESULTS

The sample included 26 SS patients, mainly boys (65.4%) with a median age of 11 (IQR 5-14). The manual muscle testing was normal in 88.5% of patients. The median distance covered in the 6-min walking test was 560.1 ± 113.4 m. Bone stiffness index scores were 70.9 ± 19.7 for children under 10 years and 88.3 ± 17.5 for children older than 10 years. The gait indicators GPS and GDI were: 7.4 ± 1.9 and 95.3 ± 9.7, respectively, for the left side and 6.8 ± 2.0 and 97.7 ± 9.5 for the right side, respectively.

CONCLUSIONS

In our series of patients with SS, we found muscle-articular involvement does not have a high impact on strength or gait problems. More work is needed to understand the effect of SS on the musculoskeletal system.

The accumulation of muscle RING finger-1 in regenerating myofibers: Implications for muscle repair in immune-mediated necrotizing myopathy

Background

Muscle RING finger-1 (MuRF-1) plays a key role in the degradation of skeletal muscle proteins. We hypothesize the involvement of MuRF-1 in immune-mediated necrotizing myopathy (IMNM).

Methods

Muscle biopsies from patients with IMNM (n = 37) were analyzed and compared to biopsies from patients with dermatomyositis (DM, n = 13), dysferlinopathy (n = 9) and controls (n = 7) using immunostaining.

Results

MuRF-1 staining could be observed in IMNM, DM and dysferlinopathy biopsies, whereas the percentage of MuRF-1 positive myofibers was significantly higher in IMNM than in dysferlinopathy (p = 0.0448), and positively correlated with muscle weakness and disease activity in IMNM and DM. Surprisingly, MuRF-1 staining predominantly presented in regenerating fibers but not in atrophic fibers. Moreover, MuRF-1-positive fibers tended to be distributed around necrotic myofibers and myofibers with sarcolemma membrane attack complex deposition. Abundant MuRF-1 expression in IMNM and DM was associated with rapid activation of myogenesis after muscle injury, whereas relatively low expression of MuRF-1 in dysferlinopathy may be attributed to damaged muscle regeneration.

Conclusions

MuRF-1 accumulated in regenerating myofibers, which may contribute to muscle injury repair in IMNM and DM. MuRF-1 staining may help clinicians differentiate IMNM and dysferlinopathy.

Randomized Trial of Tocilizumab in the Treatment of Refractory Adult Polymyositis and Dermatomyositis

Objective

To assess the efficacy and tolerability of tocilizumab in a multicenter, randomized, double‐blind, placebo‐controlled trial in refractory adult patients with dermatomyositis (DM) and polymyositis (PM).

Methods

Thirty‐six subjects with probable or definite DM/PM were enrolled in a 6‐month phase 2B clinical trial and randomized 1:1 to receive tocilizumab (8 mg/kg intravenously) or placebo every 4 weeks for 24 weeks. Eligible subjects had either a DM rash, a myositis‐associated autoantibody or an adjudicated PM diagnosis. Active disease was defined by at least three of six abnormal core set measures (CSMs), including a manual muscle testing (MMT)‐8 score of less than 136/150. If the MMT‐8 score was greater than 136, then a cutaneous score of 3 or more (10 cm visual analogue scale) was required along with three additional abnormal CSMs indicating disease activity. The primary endpoint compared the Total Improvement Score (TIS) between both arms from week 4 to 24. Secondary outcomes included time to meeting minimal TIS improvement, changes in CSMs, time to worsening, steroid‐sparing effect, proportion of subjects meeting more stringent improvement criteria, and safety outcomes.

Results

There was no significant difference (P = 0.86) in the TIS over 24 weeks between tocilizumab and placebo arms. The secondary endpoints of time to improvement (minimal, moderate, or major), time to worsening, CSM changes, safety outcomes, and steroid‐sparing effect were also not significantly different between arms.

Conclusion

Tocilizumab was safe and well tolerated but did not meet the primary or secondary efficacy outcomes in refractory DM and PM in this 24‐week phase 2B study.

A multidisciplinary approach to the diagnosis of antisynthetase syndrome

Antisynthetase syndrome is a subtype of idiopathic inflammatory myopathy, strongly associated with the presence of interstitial lung disease. Diagnosis is made by identifying myositis-specific antibodies directed against aminoacyl tRNA synthetase, and relevant clinical and radiologic features. Given the multisystem nature of the disease, diagnosis requires the careful synthesis of subtle clinical and radiological features with the interpretation of specialized autoimmune serological testing. This is provided in a multidisciplinary environment with input from rheumatologists, respiratory physicians, and radiologists. Differentiation from other idiopathic interstitial lung diseases is key; treatment and prognosis differ between patients with antisynthetase syndrome and idiopathic interstitial lung disease. In this review article, we look at the role of the multidisciplinary team and its individual members in the initial diagnosis of the antisynthetase syndrome, including the role of physicians, radiologists, and the wider team.

Thromboembolic events in idiopathic inflammatory myopathy: a retrospective study in China

OBJECTIVE

To investigate the clinical characteristics and risk factors for thromboembolic events in patients with idiopathic inflammatory myopathy (IIM).

METHODS

We retrospectively analyzed 1144 consecutive patients with IIM for arterial and venous thromboses and compared them with age- and sex-matched IIM patients without thrombosis. Logistic regression analysis was used to analyze risk factors for thrombosis.

RESULTS

Twenty-four (2.1%) patients had arterial or venous thromboses (mean age, 62.6 ± 11.6 years; range, 33-81 years). Thromboembolic events occurred in 54.2% (13/24) of patients within 6 months before or after IIM diagnosis. Thrombosis patients had a higher Cutaneous Dermatomyositis Disease Area and Severity Index score (p = 0.028), higher myositis disease activity assessment visual analogue scale score (MYOACT) (p < 0.001), and a greater proportion of them had varicose veins (p = 0.001), surgical history in the past 3 months (p = 0.039), malignancy (p = 0.018), and infection (p < 0.001). The manual muscle test 8 score (p < 0.001) and albumin level (p = 0.003) were lower in thrombosis patients. There was no significant difference between the two groups in glucocorticoid pulse therapy; however, intravenous immunoglobulin therapy was more commonly used in thrombosis patients (p = 0.04). In multivariable regression models, malignancy, infection, longer duration of glucocorticoid treatment, and higher MYOACT were risk factors for thrombosis. The cumulative survival time of IIM patients with thrombosis was significantly shorter than that of controls.

CONCLUSIONS

Malignancy, infection, longer duration of glucocorticoid use, and increased myositis disease activity are risk factors for thrombosis. Patients with these risk factors should undergo screening for thrombosis. Key Points • To investigate the clinical characteristics and risk factors for thromboembolism events in patients with IIM, we performed a retrospective study with IIM patients who experienced a thromboembolic event. • We found that malignancy, infection, longer duration of glucocorticoid treatment, and a higher level of myositis disease activity were risk factors for thrombosis. • The results suggest that patients with the above risk factors should undergo screening for thrombosis.

Assessment of Physical Activity and Muscle Function in Adult Inflammatory Myopathies

PURPOSE OF REVIEW

The aim is to summarize the outcome measures used in the assessment and monitoring of muscle function and physical activity in the management idiopathic inflammatory myopathy.

RECENT FINDINGS

Assessment techniques have progressed and matured over the past decade, and new options are now available to clinicians working in this field. Newer outcome measures, including the Functional Index-3 and wearable motion sensors are reviewed, as well as the current application of more established measures. The available outcome measures for use in clinical practice in idiopathic inflammatory myopathies with regard to muscle function and physical activity have expanded over the past 15 years. There are valid and reliable options for several domains and methods for assessing these factors. In a busy clinical setting, efficiency is important, but there also needs to be considered the choosing of tools that work together to give the fullest picture of the status of the patient.

Multidisciplinary approach to anti-MDA5 antibody-positive dermatomyositis associated with rapidly progressive interstitial lung disease

A man in his 40s was referred to our centre with rapidly progressive interstitial lung disease for lung transplant evaluation. Three months prior to his presentation he had developed periorbital oedema and discolouration, papules over the dorsal aspect of his metacarpophalangeal (MCP) joints and mucocutaneous ulcerations over the dorsum and palmar aspects of his MCPs. He had also been experiencing progressive shortness of breath. Based on the characteristic appearance of the cutaneous lesions, lack of muscle weakness on clinical examination, rapid progression of the interstitial lung disease together with presence of melanoma differentiation-associated gene 5 (MDA5) antibodies a diagnosis of anti-MDA5 dermatomyositis was made. Prompt treatment was initiated with aggressive combined immunomodulatory therapy that resulted in significant improvement in symptoms.

Endoplasmic Reticulum Stress Is Involved in Muscular Pathogenesis in Idiopathic Inflammatory Myopathies

Objectives: Endoplasmic reticulum (ER) stress plays pivotal roles in the regulation of skeletal muscle damage and dysfunction in multiple disease conditions. We postulate the activation of ER stress in idiopathic inflammatory myopathies (IIM).

Methods: Thirty-seven patients with immune-mediated necrotizing myopathy (IMNM), 21 patients with dermatomyositis (DM), 6 patients with anti-synthetase syndrome (ASS), and 10 controls were enrolled. The expression of ER stress-induced autophagy pathway was detected using histological sections, Western blot, and real-time quantitative Polymerase Chain Reaction.

Results: ER stress-induced autophagy pathway was activated in biopsied muscle of patients with IMNM, DM, and ASS. The ER chaperone protein, glucose-regulated protein 78 (GRP78)/BiP expression in skeletal muscle correlated with autophagy, myofiber atrophy, myonecrosis, myoregeneration, and disease activity in IMNM.

Conclusion: ER stress was involved in patients with IIM and correlates with disease activity in IMNM. ER stress response may be responsible for skeletal muscle damage and repair in IIM.

Targeting necroptosis in muscle fibers ameliorates inflammatory myopathies

Muscle cell death in polymyositis is induced by CD8⁺ cytotoxic T lymphocytes. We hypothesized that the injured muscle fibers release pro-inflammatory molecules, which would further accelerate CD8⁺ cytotoxic T lymphocytes-induced muscle injury, and inhibition of the cell death of muscle fibers could be a novel therapeutic strategy to suppress both muscle injury and inflammation in polymyositis. Here, we show that the pattern of cell death of muscle fibers in polymyositis is FAS ligand-dependent necroptosis, while that of satellite cells and myoblasts is perforin 1/granzyme B-dependent apoptosis, using human muscle biopsy specimens of polymyositis patients and models of polymyositis in vitro and in vivo. Inhibition of necroptosis suppresses not only CD8⁺ cytotoxic T lymphocytes-induced cell death of myotubes but also the release of inflammatory molecules including HMGB1. Treatment with a necroptosis inhibitor or anti-HMGB1 antibodies ameliorates myositis-induced muscle weakness as well as muscle cell death and inflammation in the muscles. Thus, targeting necroptosis in muscle cells is a promising strategy for treating polymyositis providing an alternative to current therapies directed at leukocytes.

Gathering patients and rheumatologists' perceptions to improve outcomes in idiopathic inflammatory myopathies

OBJECTIVE

Therapeutic targets in Idiopathic Inflammatory Myopathies (IIM) are based on the opinions of physicians/specialists, which may not reflect the main concerns of patients. The authors, therefore, assessed the outcome concerns of patients with IIM and compared them with the concerns of rheumatologists in order to develop an IIM outcome standard set.

METHODS

Ninety-three IIM patients, 51 rheumatologists, and one physiotherapist were invited to participate. An open questionnaire was initially applied. The top 10 answers were selected and applied in a multiple-choice questionnaire, inquiring about the top 3 major concerns. Answers were compared, and the agreement rate was calculated. Concerns were gathered in an IIM outcome standard set with validated measures.

RESULTS

The top three outcome concerns raised by patients were medication side effects/muscle weakness/prevention functionality loss. The top three concerns among rheumatologists were to prevent loss of functionality/to ensure the quality of life/to achieve disease remission. Other's outcomes concerns only pointed out by patients were muscle pain/diffuse pain/skin lesions/fatigue. The agreement rate between both groups was 41%. Assessment of these parameters guided the development of an IIM standard set which included Myositis Disease Activity Assessment Visual Analogue Scale/Manual Muscle Testing/fatigue and pain Global Visual Analogue Scale/Health Assessment Questionnaire/level of physical activity.

CONCLUSION

The authors propose a novel standard set to be pursued in IIM routine follow-up, which includes not only the main patients/rheumatologist outcome concerns but also additional important outcomes only indicated by patients. Future studies are necessary to confirm if this comprehensive approach will result in improved adherence and ultimately in better assistance.

Serum Myostatin and Follistatin Levels in Patients With Dermatomyositis and Polymyositis

BACKGROUND

Myostatin is a protein in the TGF-β family that negatively regulates muscle mass, and follistatin is a myostatin antagonist.

OBJECTIVE

The aim of this study was to measure serum levels of myostatin and follistatin in idiopathic inflammatory myopathy patients and correlate these levels with muscle strength, fatigue, functional capacity, damage, and serum levels of muscle enzymes.

METHODS

This was a multicenter cross-sectional study including 50 patients (34 dermatomyositis and 16 polymyositis [PM]) and 52 healthy individuals (control group [CG]). The disease status was evaluated according to the International Myositis Assessment & Clinical Studies. Fatigue was rated according to the Fatigue Severity Scale, and body composition was measured using dual-energy x-ray emission densitometry. Myostatin and follistatin were measured using enzyme-linked immunosorbent assays.

RESULTS

Mean age was 50.9 ± 14.0 years, and mean disease duration was 89.2 ± 80.9 months. There were no differences in levels of myostatin (14.15 ± 9.65 vs. 10.97 ± 6.77 ng/mL; p = 0.131) or follistatin (0.53 ± 0.71 vs. 0.49 ± 0.60 ng/mL; p = 0.968) between patients and the CG. However, myostatin levels were higher in PM than CG (16.9 ± 12.1 vs. 11.0 ± 6.8 ng/mL; p = 0.036). There was no difference in serum myostatin among patients with and without low lean mass. Patients not treated with corticosteroids had higher serum levels of myostatin than the CG. There was a weak negative correlation between follistatin and Manual Muscle Testing and a Subset of Eight Muscles and a weak positive correlation between follistatin and Healthy Assessment Questionnaire.

CONCLUSIONS

Serum levels of myostatin and follistatin did not differ between dermatomyositis and PM patients and control subjects. The assessment of serum levels of myostatin and follistatin in idiopathic inflammatory myopathy patients seems not to be helpful in clinical practice.

Efficacy and safety of intravenous and subcutaneous immunoglobulin therapy in idiopathic inflammatory myopathy: A systematic review and meta-analysis

OBJECTIVE

To perform a systematic review and meta-analysis on the efficacy and safety of intravenous (IVIg) and subcutaneous (SCIg) immunoglobulin (Ig) therapy in the treatment of idiopathic inflammatory myopathy (IIM) and juvenile dermatomyositis (JDM).

METHODS

PubMed, Embase and SCOPUS were searched to identify studies on Ig therapy in patients with IIM and/or JDM (2010-2020). Outcome measures were complete response (CR) or partial response (PR) in terms of muscle power and extramuscular disease activity measures on the International Myositis Assessment and Clinical Studies Group (IMACS) core set domains.

RESULTS

Twenty-nine studies were included (n = 576, 544 IIM, 32 JDM). Muscle power PR with pooled Ig therapy was 88.5% (95% confidence interval (CI): 80.6-93.5, n = 499) and PR with SCIg treatment was 96.61% (95% CI: 87.43-99.15, n = 59). Pooled PR with first-line use of IVIg was 77.07% (95% CI: 61.25-92.89, n = 80). Overall, mean time to response was 2.9 months (95% CI: 1.9-4.1). Relapse was seen in 22.76% (95% CI: 14.9-33). Studies on cutaneous disease activity and dysphagia showed significant treatment responses. Glucocorticoid and immunosuppressant sparing effect was seen in 40.9% (95% CI: 20-61.7) and 42.2% (95% CI: 20.4-64.1) respectively. Ig therapy was generally safe with low risk of infection (1.37%, 95% CI: 0.1-2.6).

CONCLUSIONS

Add-on Ig therapy improves muscle strength in patients with refractory IIM, but evidence on Ig therapy in new-onset disease and extramuscular disease activity is uncertain.

Home-based exercise program for adolescents with juvenile dermatomyositis quarantined during COVID-19 pandemic: a mixed methods study

BACKGROUND

Exercise has been suggested to prevent deterioration of health-related quality of life (HRQL) and overall health in pediatric rheumatologic diseases during the COVID-19 pandemic. Herein we describe the effects of a 12-week, home-based, exercise program on overall health and quality of life among quarantined patients with juvenile dermatomyositis (JDM).

METHOD

This prospective, quasi-experimental, mixed methods (qualitative and quantitative) study was conducted between July and December 2020, during the most restricted period of COVID-19 pandemic in Brazil. The home-based exercise program consisted of a 12-week, three-times-a-week, aerobic and strengthening (bodyweight) training program. Qualitative data were systematically evaluated. Strengths and Difficulties Questionnaire (SDQ), Pediatric Quality of Life Inventory (PedsQOL) and Pittsburgh Sleep Quality Index (PSQI) evaluate symptoms of mental health disorder, HRQL, and quality of sleep.

FINDINGS

11 patients (out of 27) met the inclusion criteria (91% female; mean ± SD age: 13.5 ± 3.2 years). Adherence to the intervention was 72.6%. Barriers to exercise involved poor internet connectivity, excessive weekly sessions, and other commitments. Even though not statistically significant, Self-report SDQ subscales Total Difficulties Score, Emotional Problems Score, and PedsQOL School Functioning Score improved after intervention (- 2.4; 95%confidence interval [CI] -5.1; 0.2, p = 0.06; - 1.0; 95%CI -2.2; 0.2, p = 0.09 and; 11.7; 95%CI -2.5; 25.8, p = 0.09, respectively). Remaining SDQ subscales were not altered. Six themes emerged from patients' and parents' comments (qualitative results). Patients engaged in exercise reported other health-related benefits including increased motivation, concentration and strength.

INTERPRETATION

A home-based exercise program was associated with qualitative perceptions of improvements in overall health and HRQL by quarantined adolescents with JDM during COVID-19 pandemic. Lessons from this trial may help developing interventions focused on tackling physical inactivity in JDM.

Development and Preliminary Validation of an Electromyography-Scoring Protocol for the Assessment and Grading of Muscle Involvement in Patients With Juvenile Idiopathic Inflammatory Myopathies

INTRODUCTION

We performed a pilot study in order to investigate the feasibility of an electromyography (EMG)-scoring protocol for the assessment of disease activity in juvenile idiopathic inflammatory myopathies (JIIM).

METHODS

Children with JIIM followed up in a tertiary-level care center underwent standardized clinical, laboratory, and EMG assessment. An EMG-scoring protocol was devised by a consensus panel including a pediatric neurophysiologist and two pediatric rheumatologists, based on a combined score obtained as the sum of (1) the presence of denervation signs (fibrillation potentials) and (2) motor unit remodeling (mixed pattern of short- and long-duration motor unit action potentials). The EMG-scoring protocol was then validated following the Outcome Measures in Rheumatoid Arthritis Clinical Trials filter for outcome measures in rheumatology and the consensus-based standards for the selection of health measurement instruments methodology.

RESULTS

Thirteen children (77% females) were included in the study, with a median age of 10 years (interquartile range: 7-17 years) and median disease duration of 11.8 months (interquartile range: 2.1-44.5). A total of 39 EMG examinations were evaluated. A strong positive association between a standardized tool for muscle strength assessment and the combined score was observed. No significant associations were found with both creatine kinase and erythrocyte sedimentation rate levels.

DISCUSSION

Our EMG-scoring protocol is the first standardized and reproducible tool for the neurophysiologic evaluation and grading of muscle involvement in patients with JIIM and could provide relevant additional information in the assessment and follow-up of these rare conditions.

Severe muscle damage with myofiber necrosis and macrophage infiltrates characterize anti-Mi2 positive dermatomyositis

OBJECTIVE

The aim of our study was to investigate clinical and histopathological findings in adult DM patients positive for anti-Mi2 (anti-Mi2+) antibodies compared with DM patients negative for anti-Mi2 (anti-Mi2-).

METHODS

Clinical data of adult DM patients, who fulfilled EULAR/ACR 2017 classification criteria, were gathered from electronic medical records of three tertiary Rheumatology Units. Histopathological study was carried out on 12 anti-Mi2+ and 14 anti-Mi2- muscle biopsies performed for diagnostic purpose. Nine biopsies from immune mediated necrotizing myopathy (IMNM) patients were used as control group.

RESULTS

Twenty-two anti-Mi2+ DM [90.9% female, mean age 56.5 (15.7) years] were compared with 69 anti-Mi2- DM patients [71% female, mean age 52.4 (17) years]. Anti-Mi2+ patients presented higher levels of serum muscle enzymes than anti-Mi2- patients [median (IQR) creatine-kinase fold increment: 16 (7-37)vs 3.5 (1-9.9), P <0.001] before treatment initiation. Moreover, a trend towards less pulmonary involvement was detected in anti-Mi2+ DM (9.1% vs 30.4%, P =0.05), without any case of rapidly progressive interstitial lung disease. At muscle histology, anti-Mi2+ patients showed more necrotic/degenerative fibres than anti-Mi2- patients [mean 5.3% (5) vs 0.8% (1), P <0.01], but similar to IMNM [5.9% (6), P >0.05]. In addition, the endomysial macrophage score was similar between anti-Mi2+ and IMNM patients [mean 1.2 (0.9) vs 1.3 (0.5), P >0.05], whereas lower macrophage infiltration was found in anti-Mi2- DM [mean 0.4 (0.5), <0.01].

CONCLUSIONS

Anti-Mi2+ patients represent a specific DM subset with high muscle damage. Histological hallmarks were a higher prevalence of myofiber necrosis, endomysial involvement and macrophage infiltrates at muscle biopsy.

The Vasculopathy of Juvenile Dermatomyositis: Endothelial Injury, Hypercoagulability, and Increased Arterial Stiffness

OBJECTIVE

Vasculopathy is considered central to the pathogenesis of juvenile dermatomyositis (DM) and is associated with severe extramuscular manifestations. We undertook this study to investigate the hypothesis that the vasculopathy of juvenile DM can be noninvasively tracked by examining biomarkers of endothelial injury, subclinical inflammation, hypercoagulability, and vascular arterial stiffness.

METHODS

The study population was a UK cohort of children with juvenile DM. Circulating endothelial cells (CECs) and microparticles (MPs) were identified using immunomagnetic bead extraction and flow cytometry, respectively. Plasma thrombin generation was determined using a fluorogenic assay. Cytokine and chemokine levels were measured by electrochemiluminescence. Arterial stiffness was assessed using pulse wave velocity (PWV). Results were expressed as the median and interquartile range (IQR), and statistical significance was assessed using nonparametric analyses.

RESULTS

Ninety patients with juvenile DM and 79 healthy control subjects were included. The median age of the patients was 10.21 years (IQR 6.68-13.40), and the median disease duration was 1.63 years (IQR 0.28-4.66). CEC counts were higher in all patients with juvenile DM compared to controls (median 96 cells/ml [IQR (40-192] and 12 cells/ml [IQR 8-24], respectively; P < 0.0001). Circulating MP numbers were also significantly higher in patients with active juvenile DM compared to controls (median 204.7 × 103 /ml [IQR 87.9-412.6] and 44.3 × 103 /ml [IQR 15.0-249.1], respectively; P < 0.0001). MPs were predominantly of platelet and endothelial origin. Enhanced plasma thrombin generation was demonstrated in patients with active juvenile DM compared to those with inactive disease (P = 0.0003) and controls (P < 0.0001). Carotid-radial PWV adjusted for age was increased in patients with juvenile DM compared to controls (P = 0.003).

CONCLUSION

We observed increased endothelial injury and increased levels of proinflammatory cytokines in patients with active juvenile DM. MP profiles reflected distinct disease activity status in juvenile DM and are markers of vascular pathology, platelet activation, and thrombotic propensity. Ongoing long-term vascular injury may result in increased arterial stiffness in patients with juvenile DM.

Chronic Onset Form of Anti-HMG-CoA Reductase Myopathy

We report a case of anti-HMGCR myopathy mimicking limb-girdle muscular dystrophy in a 27-year-old male patient with no history of statin intake and presenting with a chronic onset form over 3 years. Treatment with prednisone and methotrexate was initiated with an insufficient response, so intravenous immunoglobulin was added. One year after initial treatment was started, as levels of creatine kinase (CK) were >1000 U/l, treatment with rituximab was added. Despite a 3-year delay before treatment, muscle strength improved even though CK levels remain elevated.

Feasibility of a blended therapy approach in the treatment of patients with inflammatory myopathies

Background

Inflammatory myopathies (IMs) are a group of rare conditions characterized by proximal and often symmetrical muscle weakness and reduced muscle endurance. The recommended medical treatment is based on corticosteroids in combination with immunosuppressants. This anti-inflammatory therapy serves to inhibit and prevent inflammation but does not influence impaired muscle strength. Exercise, particularly progressive resistance training, plays therefore an important role in IMs management. Blended therapy, a combination of face-to-face treatment and telerehabilitation, may be a powerful therapy option in improving exercise program adherence in these patients.

Methods

The feasibility of a 12-week interactive tablet-based home exercise program combined with face-to-face therapy sessions – a ‘blended therapy’ approach - was evaluated using a quasi-experimental one-group pre-post comparison design. Primary outcomes were recruitment, attrition and adherence rates, plus measures of acceptance (Technology Acceptance Model Questionnaire (TAM)) and satisfaction (satisfaction questionnaire). Secondary outcomes comprised potential effects of the intervention on muscle strength and function, activity limitation, disability and health-related quality of life.

Results

Thirteen of the included 14 participants completed the study without any related adverse events. Mean adherence to exercise program was 84% (range: 25–100%) and participants indicated high acceptance of the intervention with mean TAM scores between 6.1 and 6.5 points. Overall satisfaction with the therapy sessions, the home program, and the technology was good. Approximately half the participants wished for longer training periods and more training sessions per week. There were inconsistent effects on muscle strength, muscle function, activity limitation, disability, and health-related quality of life.

Conclusion

Blended therapy combining the use of an interactive tablet-based resistance training program with face-to-face therapy sessions is feasible and safe and participants` acceptance with this approach was high. Furthermore, results were obtained that might be useful in selecting appropriate assessments and sample sizes in future trials.

Trial registration

NCT03713151.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40945-021-00108-z.

MRI and muscle imaging for idiopathic inflammatory myopathies

Although idiopathic inflammatory myopathies (IIM) are a heterogeneous group of diseases nearly all patients display muscle inflammation. Originally, muscle biopsy was considered as the gold standard for IIM diagnosis. The development of muscle imaging led to revisiting not only the IIM diagnosis strategy but also the patients' follow-up. Different techniques have been tested or are in development for IIM including positron emission tomography, ultrasound imaging, ultrasound shear wave elastography, though magnetic resonance imaging (MRI) remains the most widely used technique in routine. Whereas guidelines on muscle imaging in myositis are lacking here we reviewed the relevance of muscle imaging for both diagnosis and myositis patients' follow-up. We propose recommendations about when and how to perform MRI on myositis patients, and we describe new techniques that are under development.

Longitudinal observational study investigating outcome measures for clinical trials in inclusion body myositis

OBJECTIVE

To describe decline in muscle strength and physical function in patients with sporadic inclusion body myositis (IBM).

METHODS

Manual muscle testing (MMT), quantitative muscle testing (QMT) and disability scoring using the IBM Functional Rating Scale (IBMFRS) were undertaken for 181 patients for up to 7.3 years. The relationship between MMT, QMT and IBMFRS composite scores and time from onset were examined using linear mixed effects models adjusted for gender and age of disease onset. Adaptive LASSO regression analysis was used to identify muscle groups that best predicted the time elapsed from onset. Cox proportional hazards regression was used to evaluate time to use of a mobility aid.

RESULTS

Multilevel modelling of change in percentage MMT, QMT and IBMFRS score over time yielded an average decline of 3.7% (95% CI 3.1% to 4.3%), 3.8% (95% CI 2.7% to 4.9%) and 6.3% (95% CI 5.5% to 7.2%) per year, respectively. The decline, however, was not linear, with steeper decline in the initial years. Older age of onset was associated with a more rapid IBMFRS decline (p=0.007), but did not influence the rate of MMT/QMT decline. Combination of selected muscle groups allowed for generation of single measures of patient progress (MMT and QMT factors). Median (IQR) time to using a mobility aid was 5.4 (3.6-9.2) years, significantly affected by greater age of onset (HR 1.06, 95% CI 1.04 to 1.09, p<0.001).

CONCLUSION

This prospective observational study represents the largest IBM cohort to date. Measures of patient progress evaluated in this study accurately predict disease progression in a reliable and useful way to be used in trial design.

Decreased Muscular Perfusion in Dermatomyositis: Initial Results Detected by Inflow-Based Vascular-Space-Occupancy MRI

OBJECTIVE. This study aimed to determine whether inflow-based vascular-space-occupancy (iVASO) MRI could reproducibly quantify skeletal muscle perfusion and differentiate patients with dermatomyositis (DM) from healthy subjects. MATERIALS AND METHODS. A total of 25 patients with DM and 22 healthy volunteers underwent iVASO MRI in a 3-T MRI scanner. Maximum and mean arteriolar muscle blood volume (MBV) values of four subgroups of muscles (normal muscles, morphologically normal-appearing muscles, edematous muscles, and atrophic or fat-infiltrated muscles) were obtained. Maximum and mean arteriolar MBV values were compared among the different subgroups, and repeat testing was performed in 20 subjects to assess reproducibility. RESULTS. Compared with normal muscles in healthy subjects, morphologically normal-appearing muscles, edematous muscles, and atrophic or fat-infiltrated muscles in patients with DM showed a significant decrease of both maximum and mean arteriolar MBV (p < .001). Both parameters were significantly lower in atrophic or fat-infiltrated muscles than in morphologically normal-appearing and edematous muscles (p < .001). ROC AUCs for discriminating patients with DM from healthy volunteers were 0.842 and 0.812 for maximum and mean arteriolar MBV values, respectively. As a measure of test-retest studies, the intraclass correlation coefficients (ICCs) were 0.990 (95% CI, 0.986-0.993) and 0.990 (95% CI, 0.987-0.993) for maximum and mean arteriolar MBV, respectively. For interobserver reproducibility, the ICCs were 0.989 (95% CI, 0.986-0.991) and 0.980 (95% CI, 0.975-0.983), respectively. CONCLUSION. iVASO MRI can reproducibly quantify arteriolar MBV in the thigh and discriminate between healthy volunteers and patients with DM.

Clinical characteristics of Vietnamese patients with idiopathic inflammatory myopathies and autoantibodies to aminoacyl-transfer RNA synthetases

OBJECTIVE

To assess clinical phenotypes of anti-aminoacyl-transfer RNA synthetases (aaRS) autoantibodies in Vietnamese patients of Kinh ethnicity with idiopathic inflammatory myopathies (IIM).

METHODS

In a cross-sectional study 23 patients with anti-aaRS autoantibodies were compared to 36 patients with other myositis-specific antibodies and to 69 seronegative patients with IIM. Assessments included muscle performance, extra-muscular involvement, and disease activity according to the International Myositis Assessment and Clinical Studies (IMACS). Sera were tested by a line immunoassay (Euroline Myositis Profile 4).

RESULTS

The frequency of anti-Jo-1 antibodies was 56.5%, anti-EJ antibodies 26.1%, and anti-PL-7 antibodies 17.4%, while anti-PL-12 and anti-OJ antibodies were not present in any case. All patients with anti-aaRS autoantibodies had signs of myositis. At time of investigation 22/23 patients had muscle weakness, 52.2% arthritis, 34.8% Raynaud's phenomenon, 73.9% fever, 14.3% mechanic's hands and 56.5% dysphagia. Interstitial lung disease was present in 52.2%, and pulmonary hypertension in 56.5%. The anti-aaRS autoantibody positive group had higher disease activity in the domains of skin and pulmonary disease compared to the seronegative group and had lower disease activity in skeletal disease compared to the anti-melanoma differentiation-associated protein 5-positive patients. The clinical presentation of antisynthetase syndrome was similar between the aaRS autoantibody specificities with the exception of more frequent pulmonary hypertension in anti-Jo-1 positive patients.

CONCLUSIONS

Different aaRS autoantibody specificities may vary between different ethnic populations for reasons that still need to be clarified. Furthermore, the high frequency of pulmonary hypertension is noteworthy but otherwise clinical manifestations associated with aaRS autoantibodies did not differ from other ethnic populations.

Outcome Scores in Pediatric Rheumatology

PURPOSE OF REVIEW

Providing a summary of the latest research on outcome measures in juvenile idiopathic arthritis, childhood -onset systemic lupus erythematosus, and juvenile dermatomyositis.

RECENT FINDINGS

A rational management of patients with pediatric rheumatic diseases requires the regular assessment of the level of disease activity and damage, as well as the evaluation of therapeutic response through validated and standardized outcome measures. Ideally, such tools should be simple, feasible, and easily applicable in routine care. Recently, there has been a great deal of effort to refine existing tools and devise novel outcome measures, aiming to address the various aspects of disease impact and to improve the reliability of research studies and clinical trials. The newest outcome tools in pediatric rheumatology have markedly enlarged the spectrum of health domains assessable in a standardized way, thus increasing the reliability of evaluation of clinical response and fostering future clinical trials.

Correlation of a Modified Disease Activity Score (DAS) with the Validated Original DAS in Patients with Juvenile Dermatomyositis

OBJECTIVE

Juvenile dermatomyositis (JDM) is a rare disease in children that is treatable, but patients may suffer from long-term effects. Clinical trials are needed to find better treatments for affected patients. Among validated tools for evaluating disease activity clinically is the Disease Activity Score (DAS), but it is not routinely collected in all clinics. We developed a modified DAS (DAS_mod), which can be scored using data routinely collected by our clinical staff and has been used in previous studies. The aim of this study was to determine if our DAS_mod correlates with the validated DAS in patients with JDM.

METHODS

In this study, we used DAS_mod (scored 0-12) and DAS (scored 0-20) scores for patients with JDM in our clinic. We analyzed the correlation between the DAS_mod and the validated DAS.

RESULTS

For 51 patients seen in our JDM clinic, the median (IQR) DAS_mod score was 2.0 (0-4.0) and the DAS score was 3.0 (0-5.5). Scores on the 2 tools were highly positively correlated (r = 0.94, P < 0.001, 95% CI 0.89-0.96). The linear regression was significant [R² = 0.88, F (1, 49) = 357.60, P < 0.001] and in this dataset, the tools can be used interchangeably with the regression equation: DAS score = -0.26 + 1.5*DAS_mod.

CONCLUSION

If the regression equation from this dataset is successfully tested against future datasets, then further research collaborations between centers that collect different data related to disease activity in children with JDM will be facilitated.

Juvenile Dermatomyositis: Advances in Pathogenesis, Assessment, and Management

BACKGROUND

Juvenile dermatomyositis is the most common inflammatory myopathy in the pediatric age group and a major cause of mortality and morbidity in individuals with childhood rheumatic diseases. Mounting evidence suggests that early diagnosis and timely aggressive treatment are associated with better outcomes.

OBJECTIVE

The purpose of this article is to provide readers with an update on the evaluation, diagnosis, and the treatment of juvenile dermatomyositis.

METHODS

A PubMed search was performed in Clinical Queries using the key term "juvenile dermatomyositis" in the search engine. The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews. The search was restricted to English literature. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

Juvenile dermatomyositis is a chronic autoimmune inflammatory condition characterized by systemic capillary vasculopathy that primarily affects the skin and muscles with possible involvement of other organs. In 2017, the European League Against Rheumatism (EULAR) and the American College of Rheumatology (ACR) developed diagnostic criteria for juvenile idiopathic inflammatory myopathies and juvenile dermatomyositis. In the absence of muscle biopsies which are infrequently performed in children, scores (in brackets) are assigned to four variables related to muscle weakness, three variables related to skin manifestations, one variable related to other clinical manifestations, and two variables related to laboratory measurements to discriminate idiopathic inflammatory myopathies from non-idiopathic inflammatory myopathies as follows: objective symmetric weakness, usually progressive, of the proximal upper extremities (0.7); objective symmetric weakness, usually progressive, of the proximal lower extremities (0.8); neck flexors relatively weaker than neck extensors (1.9); leg proximal muscles relatively weaker than distal muscles (0.9); heliotrope rash (3.1); Gottron papules (2.1); Gottron sign (3.3); dysphagia or esophageal dysmotility (0.7); the presence of anti-Jo-1 autoantibody (3.9); and elevated serum levels of muscle enzymes (1.3). In the absence of muscle biopsy, a definite diagnosis of idiopathic inflammatory myopathy can be made if the total score is ≥7.5. Patients whose age at onset of symptoms is less than 18 years and who meet the above criteria for idiopathic inflammatory myopathy and have a heliotrope rash, Gottron papules or Gottron sign are deemed to have juvenile dermatomyositis. The mainstay of therapy at the time of diagnosis is a high-dose corticosteroid (oral or intravenous) in combination with methotrexate.

CONCLUSION

For mild to moderate active muscle disease, early aggressive treatment with high-dose oral prednisone alone or in combination with methotrexate is the cornerstone of management. Pulse intravenous methylprednisolone is often preferred to oral prednisone in more severely affected patients, patients who respond poorly to oral prednisone, and those with gastrointestinal vasculopathy. Other steroid-sparing immunosuppressive agents such as cyclosporine and cyclophosphamide are reserved for patients with contraindications or intolerance to methotrexate and for refractory cases, as the use of these agents is associated with more adverse events. Various biological agents have been used in the treatment of juvenile dermatomyositis. Data on their efficacy are limited, and their use in the treatment of juvenile dermatomyositis is considered investigational.

Development and Testing of Reduced Versions of the Manual Muscle Test-8 in Juvenile Dermatomyositis

OBJECTIVE

To develop and test shortened versions of the Manual Muscle Test-8 (MMT-8) in juvenile dermatomyositis (JDM).

METHODS

Construction of reduced tools was based on a retrospective analysis of individual scores of MMT-8 muscle groups in 3 multinational datasets. The 4 and 6 most frequently impaired muscle groups were included in MMT-4 and MMT-6, respectively. Metrologic properties of reduced tools were assessed by evaluating construct validity, internal consistency, discriminant ability, and responsiveness to change.

RESULTS

Neck flexors, hip extensors, hip abductors, and shoulder abductors were included in MMT-4, whereas MMT-6 also included elbow flexors and hip flexors. Both shortened tools revealed strong correlations with MMT-8 and other muscle strength measures. Correlations with other JDM outcome measures were in line with predictions. Internal consistency was good (0.88-0.96) for both MMT-4 and MMT-6. Both reduced tools showed strong ability to discriminate between disease activity states, assessed by the caring physician or a parent (P < 0.001), and between patients whose parents were satisfied or not satisfied with illness course (P < 0.001). Responsiveness to change (assessed by both standardized response mean and relative efficiency) of MMT-4 and, to a lesser degree, MMT-6, was slightly superior to that of MMT-8.

CONCLUSION

Overall, the metrologic performance of MMT-4 and MMT-6 was comparable to that of the other established muscle strength tools, which indicates that they may be suitable for use in clinical practice and research, including clinical trials. The measurement properties of these tools should be further tested in other patient populations and evaluated prospectively.

Interleukin-35 in idiopathic inflammatory myopathies

BACKGROUND

Interleukin-35 (IL-35) is a recently described heterodimeric cytokine that belongs to the IL-12 family and consists of p35 (IL-12a) and EBI3 (IL-27b) subunits. The expression of IL-35 in humans is inducible in response to inflammatory stimuli. Increased IL-35 levels were documented in several autoimmune inflammatory diseases, suggesting a possible immunomodulatory role in their pathogenesis.

OBJECTIVES

The aim of this study was to explore a potential role of IL-35 in the pathogenesis of idiopathic inflammatory myopathies (IIM) by studying the expression of IL-35 subunits in muscle biopsy samples and by evaluating serum levels of IL-35 and their association with disease activity in IIM patients.

METHODS

The expression of IL-35 subunits was studied in serial sections of 9 muscle biopsy samples [4 polymyositis (PM), 5 dermatomyositis (DM)] and in 7 non-inflammatory control muscle biopsies. Serum levels of IL-35 were measured in 23 PM, 28 DM and 15 cancer associated myositis (CAM) patients as well as in 40 healthy controls. Disease activity was evaluated using the Myositis Disease Activity Assessment Tool (MDAAT) and by serum muscle enzymes.

RESULTS

Expression of both IL-35 subunits was evident in the inflammatory infiltrates in IIM muscle biopsies, while no IL-35 expression was observed in control muscle samples. IL-35 serum levels were increased in all IIM patients compared to healthy controls [median 119.5 (range 32.1-1074.5) vs 36.2 (range 1.5-86.5) pg/ml, P < 0.001]. There were no differences in IL-35 serum levels between myositis subgroups (DM, PM or CAM). Serum IL-35 levels correlated significantly with physician's assessment of global (r = 0.29, p = 0.021), muscle (r = 0.30, p = 0.017) and extramuscular (r = 0.30, p = 0.016) disease activity as well as creatine kinase (r = 0.26, p = 0.044) and lactate dehydrogenase (r = 0.40, p = 0.003) levels. There was a significant correlation with pulmonary activity in patients with interstitial lung disease (r = 0.39, p = 0.037). Serum IL-35 correlated negatively with duration of treatment (r = -34, p = 0.009).

CONCLUSIONS

IL-35 is overexpressed in inflammatory infiltrates in muscle tissue and serum in IIM patients and there is correlation with several disease activity parameters. These data suggest potential role of locally produced IL-35 in the pathogenesis of inflammatory myopathies.

Update on dermatomyositis in adults

Dermatomyositis (DM) in adults has a prevalence of 6-7 per 100,000 population per year. This dedicated compact overview was prepared due to an increasing incidence as well as an often underestimated systemic involvement and new developments in myositis-specific antibodies (MSA). The spectrum of clinical dermatological and systemic symptoms is described. Related diagnostic procedures are depicted, and therapeutic regimens based on the German S2k guidelines and the current literature are presented. The urgency of an early diagnosis is emphasized as about 30 % of patients with DM manifest a tumor. Etiopathology is often associated with pulmonary fibrosis, and inflammation of myositis can cause irreversible muscle damage. Clinical signs and correct interpretation of serological markers can deliver valuable information on the extent of DM, and provide an indication for further diagnostic procedures, prognosis and choice of therapy.

Patient insights on living with idiopathic inflammatory myopathy and the limitations of disease activity measurement methods - a qualitative study

Background

The idiopathic inflammatory myopathies (IIMs) are chronic autoimmune conditions, typically resulting in proximal muscle weakness and impacting upon quality of life. Accurate measurement of IIM disease activity is imperative for appropriate medical management and carrying out valid clinical trials. The International Myositis Assessment and Clinical Studies Group (IMACS) “Disease Activity Core Set Measures” are the current gold-standard of IIM disease activity assessment. Anecdotally, patients with an IIM report that the IMACS Core Set Measures and other available methods do not necessarily capture their perceived disease activity. Investigating the patient experiences of living with an IIM and their views on the accuracy of the IMACS Core Set Measures will provide valuable insights for both clinical and research purposes.

Methods

Eighteen interviews with patients with an IIM were carried out and analysed thematically, using a grounded theory approach. Experiences on living with an IIM and perceptions on the accuracy of disease activity measurement methods were explored.

Results

Interview analysis revealed four themes: 1) fatigue, 2) pain, 3) day-to-day symptom variation, 4) limitations of creatine kinase levels and manual muscle testing.

Conclusions

This study has provided valuable insights into patient experiences of living with an IIM. Aspects of IIM disease activity perceived not to be wholly measured by the IMACS Core Set Measures have also been identified. These findings have implications for future IIM clinical care and research, in particular providing justification for research into pain, fatigue and symptom variation.