Distribution and severity of weakness among patients with polymyositis, dermatomyositis and juvenile dermatomyositis

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Inaugural dropped head syndrome and camptocormia in inflammatory myopathies: a retrospective study

OBJECTIVES

Inaugural axial muscle involvement, defined as dropped head syndrome (DHS) and/or camptocormia (CC), is poorly described in inflammatory myopathies (IM). This study aimed to further characterize IM patients with inaugural DHS/CC, their outcome and care management.

METHODS

This retrospective study included IM patients diagnosed between 2000 and 2021. The main inclusion criterion was IM revealed by axial muscle deficit (DHS/CC).

RESULTS

Twenty-seven patients were included; median (IQR) age at first symptoms was 66.0 years (55.5-75.0); 21 were female (77.8%). There were nine IBM, 33.3%, nine overlap myositis (OM, 33.3%), five DM, 18.5%, two immune checkpoint inhibitor-related myositis (7.4%), one focal myositis (3.7%) and one myositis with anti-Hu antibodies (3.7%). Age at first symptoms was ≤70 years in 16 patients (59.3%), including all DM patients and 8/9 OM patients (88.9%). In this group, partial remission of the disease was obtained in 9/16 (56.3%) and complete remission in 1/16 patients (6.3%); regression of DHS/CC was achieved in 3/16 patients (18.8%). Conversely, in the group of 11 patients aged >70 years at first symptoms, there were eight IBM (72.7%). Partial remission was obtained in 5/11 patients (45.5%), the disease was stable in 6/11 patients (54.5%); no complete remission was obtained nor regression of DHS/CC.

CONCLUSION

The analysis of IM patients with inaugural DHS/CC delineates two groups of patients according to the age at first symptoms in terms of clinical and outcome specificities, and proposes an adapted diagnostic and care management approach to prevent long-term complications.

Work situation, work ability and expectation of returning to work in patients with systemic autoimmune myopathies

OBJECTIVES

To document the work situation, the work ability and the expectation of returning to work among adult patients with systemic autoimmune myopathies (SAMs), and to identify the factors associated with each of these outcomes.

METHODS

Cross-sectional study. The work situation (performing paid work vs out of work) was ascertained via a structured questionnaire. For those who were working, we applied the Work Ability Index (WAI; scale 7-49); and for those who were out of work, we applied the Return-to-Work Self-Efficacy questionnaire (RTW-SE; scale 11-66).

RESULTS

Of the 75 patients with SAMs included, 33 (44%) were doing paid work and 42 (56%) were out of work. The work situation was independently associated with physical function, assessed by the Health Assessment Questionnaire-Disability Index (HAQ-DI). A 1-point increase in the HAQ-DI (scale 0-3) decreased the chance of doing paid work by 66% (95% CI: 0.16, 0.74; P = 0.007). Patients performing paid work had a mean WAI of 33.5 (6.9). The following variables were associated with a decrease in the WAI score in the regression model: female sex (-5.04), diabetes (-5.94), fibromyalgia (-6.40), fatigue (-4.51) and severe anxiety (-4.59). Among those out of work, the mean RTW-SE was 42.8 (12.4). Cutaneous manifestations and >12 years of education were associated with an average increase of 10.57 and 10.9 points, respectively, in the RTW-SE. A 1-point increase in the HAQ-DI decreased the RTW-SE by 4.69 points.

CONCLUSION

Our findings highlight the poor work participation in a well-characterized sample of working-age patients with SAMs. Strategies to improve work-related outcomes in these patients are urgently needed.

Performance of timed function tests as outcome measures in idiopathic inflammatory myopathy-results from a single-centre cohort

OBJECTIVE

To evaluate performance of timed function tests (TFTs) in assessing muscle strength and endurance as determined by Manual Muscle Testing 8 (MMT-8) and Functional Index 2 (FI-2), respectively, in idiopathic inflammatory myopathies (IIM).

METHODS

This cohort study included 42 IIM patients satisfying 2017 EULAR/ACR criteria. Patients were classified as active (n = 18) or inactive disease (n = 24) based on clinical status at baseline. MMT-8, FI-2, 30 s rise from chair test, 30 s 1 kg arm rise test and 2-min walking distance (2MWD) were administered at baseline, 3 months and 6 months. Pearson rank correlation analysis and receiver operating curves were performed to assess the performance of timed function tests.

RESULTS

All patients were followed up at 3 months and 39 completed 6 months' follow-up. All the three TFTs had excellent convergent (r > 0.7, P < 0.05) and divergent validity (P < 0.05). Only 2MWD had moderate to strong correlation with ΔMMT-8 at 3 and 6 months among those with active disease (P = 0.001). All the TFTs correlated with ΔFI-2 in active disease but only Δ2MWD correlated with ΔFI-2 in inactive disease at 6 months (r = 0.506, P = 0.036). At a cut-off of 5% improvement in MMT-8, 2MWD had an area under the curve (AUC) of 0.868 with 95% sensitivity with 2% improvement at 3 months. To detect a 10% ΔMMT-8, Δ2MWD at a cut of 8% and 7% had an AUC of 0.909 and 0.893 with a sensitivity of 92% at 3 and 6 months, respectively (P < 0.05).

CONCLUSION

2MWD is a reliable indicator of muscle strength, endurance and treatment response. The 2MWD can be self-administered by patients, making it a potential patient-reported outcome measure.

The clinical features of juvenile dermatomyositis: A single-centre inception cohort

INTRODUCTION

Juvenile Dermatomyositis (JDM), a severe and rare autoimmune disease, is the most common idiopathic inflammatory myopathy in children. We describe the clinical features of a large single-centre cohort.

METHODS

We studied an inception cohort (0-18 years old) referred for diagnosis to the JDM clinic at The Hospital for Sick Children (SickKids), between January 1989 and September 2017. Probable or definite diagnosis of JDM was done according to the 2017 ACR/EULAR Criteria. We excluded children who had treatment started at another hospital. The data were collected retrospectively from clinical charts and the SickKids JDM database.

RESULTS

172/230 (74.8%) patients were included. They were most often female (female:male = 1.8:1); the age at diagnosis was 8.5±4.3 years. There was a positive family history for autoimmune disease in 52%, mainly rheumatoid arthritis. No patient died. The most common signs at inception were muscle weakness (85.5%), nailfold capillary abnormalities (83.4%), Gottron papules (78.5%), heliotrope rash (66.3%), abnormal gait (55.8%), and malar/facial rash (54.7%). The prevalence of Gottron papules, heliotrope rash, facial/malar rash, nailfold capillary abnormalities, Raynaud phenomenon, dysphonia/dysphagia (a frequent cause of hospitalization), mouth ulcers, calcinosis, eye problems, joint involvement, acanthosis nigricans and lipodystrophy increased during follow-up. Muscle enzymes, namely CK, ALT, AST, were often normal or only slightly raised despite active muscle disease; conversely LD was often high. Anti-Nuclear Autoantibodies were positive in 49.7% of patients at diagnosis. The course of the disease was: 29.1% monocyclic, 5.3% polycyclic, 33.1% chronic. The course of 56 patients (32.5%) was not classifiable due to length of follow-up. Corticosteroids were used as treatment in almost all our patients and 30% required intravenous therapy due to the severity of the presentation; methotrexate was added in 64%, more often in recent years. Unresponsive patients were treated mostly with intravenous immunoglobulins (IVIG).

CONCLUSIONS

The information obtained from this relatively large number of patients adds to the growing knowledge base of this rare disease.

TRIAL REGISTRATION

SickKids Research Ethics Board approved the study.

Demographic, clinical, laboratory data, prognostic, and treatment features of patients with antisynthetase syndrome: An international, two-center cohort study

Objectives: To compare clinical, demographic, laboratory data, prognostic and treatment characteristics of patients with antisynthetase syndrome (ASSD) treated in two different centers of India and Brazil.

Patients and methods: This international, two-center, retro-prospective cohort study which was conducted at two tertiary rheumatology centers (one in Brazil and one in India) between January 2000 to January 2020 included a total of 115 patients with ASSD (21 males, 94 females; mean age; at disease diagnosis at 40.3; range, 18 to 80 years). Demographic, clinical and laboratory data of the patients were recorded. Clinical involvement was evaluated.

Results: Of the patients, 81 were Brazilians and 34 were of Indian origin. The Indian group exhibited a greater delay in diagnosis after the onset of symptoms compared to Brazilian patients (12 vs. 6 months, respectively; p=0.026). Brazilian patients exhibited a significantly higher prevalence of joint and lung involvement, mechanic’s hands, and Raynaud’s phenomenon. Anti-Jo-1 was the most common autoantibodies in both groups. Systemic arterial hypertension, followed by diabetes mellitus were the most prevalent comorbidities. Concerning previously used drugs, the Indian patients had a larger group of patients treated with antimalarials, whereas the Brazilian group used more azathioprine and intravenous immunoglobulin. A higher proportion of Indian patients was treated with one immunosuppressive drug (70.6%), while the Brazilian group were often treated using two immunosuppressive drugs (33%). Comparison between the severity and prognosis showed that Brazilian group had a higher number of relapses, and during follow-up, the global mortality rates were similar in both groups (6.2% for Brazilian vs. 8.8% for Indian).

Conclusion: Brazilian and Indian patients with ASSD have comparable epidemiological characteristics such as age at the time of disease diagnosis, and sex distribution, and autoantibodies. Diagnostic delay is seen in Indian patients, and Brazilians exhibit a higher prevalence of joint and lung involvement, mechanic’s hands, Raynaud’s phenomenon with a higher number of relapses, although the mortality rate seems to be similar in both groups.

Improved skeletal muscle fatigue resistance in experimental autoimmune myositis mice following high-intensity interval training

Background

Muscle weakness and decreased fatigue resistance are key manifestations of systemic autoimmune myopathies (SAMs). We here examined whether high-intensity interval training (HIIT) improves fatigue resistance in the skeletal muscle of experimental autoimmune myositis (EAM) mice, a widely used animal model for SAM.

Methods

Female BALB/c mice were randomly assigned to control (CNT) or EAM groups (n = 28 in each group). EAM was induced by immunization with three injections of myosin emulsified in complete Freund’s adjuvant. The plantar flexor (PF) muscles of mice with EAM were exposed to either an acute bout or 4 weeks of HIIT (a total of 14 sessions).

Results

The fatigue resistance of PF muscles was lower in the EAM than in the CNT group (P < 0.05). These changes were associated with decreased activities of citrate synthase and cytochrome c oxidase and increased expression levels of the endoplasmic reticulum stress proteins (glucose-regulated protein 78 and 94, and PKR-like ER kinase) (P < 0.05). HIIT restored all these alterations and increased the peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and the mitochondrial electron transport chain complexes (I, III, and IV) in the muscles of EAM mice (P < 0.05).

Conclusions

HIIT improves fatigue resistance in a SAM mouse model, and this can be explained by the restoration of mitochondria oxidative capacity via inhibition of the ER stress pathway and PGC-1α-mediated mitochondrial biogenesis.

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.

Demographic, clinical, laboratory data, prognostic, and treatment features of patients with antisynthetase syndrome: An international, two-center cohort study

Objectives

To compare clinical, demographic, laboratory data, prognostic and treatment characteristics of patients with antisynthetase syndrome (ASSD) treated in two different centers of India and Brazil.

Patients and methods

This international, two-center, retro-prospective cohort study which was conducted at two tertiary rheumatology centers (one in Brazil and one in India) between January 2000 to January 2020 included a total of 115 patients with ASSD (21 males, 94 females; mean age; at disease diagnosis at 40.3; range, 18 to 80 years). Demographic, clinical and laboratory data of the patients were recorded. Clinical involvement was evaluated.

Results

Of the patients, 81 were Brazilians and 34 were of Indian origin. The Indian group exhibited a greater delay in diagnosis after the onset of symptoms compared to Brazilian patients (12 vs. 6 months, respectively; p=0.026). Brazilian patients exhibited a significantly higher prevalence of joint and lung involvement, mechanic's hands, and Raynaud's phenomenon. Anti-Jo-1 was the most common autoantibodies in both groups. Systemic arterial hypertension, followed by diabetes mellitus were the most prevalent comorbidities. Concerning previously used drugs, the Indian patients had a larger group of patients treated with antimalarials, whereas the Brazilian group used more azathioprine and intravenous immunoglobulin. A higher proportion of Indian patients was treated with one immunosuppressive drug (70.6%), while the Brazilian group were often treated using two immunosuppressive drugs (33%). Comparison between the severity and prognosis showed that Brazilian group had a higher number of relapses, and during follow-up, the global mortality rates were similar in both groups (6.2% for Brazilian vs. 8.8% for Indian).

Conclusion

Brazilian and Indian patients with ASSD have comparable epidemiological characteristics such as age at the time of disease diagnosis, and sex distribution, and autoantibodies. Diagnostic delay is seen in Indian patients, and Brazilians exhibit a higher prevalence of joint and lung involvement, mechanic's hands, Raynaud's phenomenon with a higher number of relapses, although the mortality rate seems to be similar in both groups.

OptimisAtion of Diagnostic Accuracy in idioPathic inflammaTory myopathies (ADAPT study): a protocol for a prospective diagnostic accuracy study of multimodality testing in patients suspected of a treatable idiopathic inflammatory myopathy

INTRODUCTION

Idiopathic inflammatory myopathies (IIMs) excluding inclusion body myositis (IBM) are a group of heterogeneous autoimmune disorders characterised by subacute-onset and progressive proximal muscle weakness, which are frequently part of a multisystem autoimmune disorder. Reaching the diagnosis can be challenging, and no gold standard for the diagnosis of IIM exists. Diagnostic modalities include serum creatine kinase activity, muscle imaging (MRI or ultrasound (US)), electromyography (EMG), myositis autoantibody testing and muscle biopsy. Several diagnostic criteria have been developed for IIMs, varying in reported sensitivity and specificity.

HYPOTHESIS

We hypothesise that an evidence-based diagnostic strategy, using fewer and preferably the least invasive diagnostic modalities, can achieve the accuracy of a complete panel of diagnostic tests, including MRI, US, EMG, myositis-specific autoantibody testing and muscle biopsy.

METHODS AND ANALYSIS

The OptimizAtion of Diagnostic Accuracy in idioPathic inflammaTory myopathies study is a prospective diagnostic accuracy study with an over-complete study design. 100 patients suspected of an IIM excluding IBM will be included. A reference diagnosis will be assigned by an expert panel using all clinical information and all results of all ancillary tests available, including 6 months of follow-up. Several predefined diagnostic strategies will be compared against the reference diagnosis to find the optimal diagnostic strategy.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the medical ethics committee of the Academic Medical Centre, University of Amsterdam, The Netherlands (2019-814). The results will be distributed through conference presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER

Netherlands trial register; NL8764.

Systemic autoimmune myopathies: A prospective phase 4 controlled trial of an inactivated virus vaccine against SARS-CoV-2

Objectives

To evaluate immunogenicity and safety of an inactivated SARS-CoV-2 vaccine in systemic autoimmune myopathies (SAMs) and the possible influence of baseline disease parameters, comorbidities and therapy on immune response.

Methods

This prospective controlled study included 53 patients with SAMs and 106 non-immunocompromised control group (CTRL). All participants received two doses of the Sinovac-CoronaVac vaccine (28-day interval). Immunogenicity was assessed by anti-SARS-CoV-2 S1/S2 IgG seroconversion (SC), anti-S1/S2 IgG geometric mean titre (GMT), factor increase GMT (FI-GMT), neutralizing antibodies (NAb) positivity, and median neutralizing activity after each vaccine dose (D0 and D28) and six weeks after the second dose (D69). Participants with pre-vaccination positive IgG serology and/or NAb and those with RT-PCR confirmed COVID-19 during the protocol were excluded from immunogenicity analysis.

Results

Patients and CTRL had comparable sex (P>0.99) and age (P=0.90). Immunogenicity of 37 patients and 79 CTRL-naïve participants revealed at D69, a moderate but significantly lower SC (64.9% vs 91.1%, P<0.001), GMT [7.9 (95%CI 4.7–13.2) vs 24.7 (95%CI 30.0–30.5) UA/ml, P<0.001] and frequency of NAb (51.4% vs 77.2%, P<0.001) in SAMs compared with CTRL. Median neutralizing activity was comparable in both groups [57.2% (interquartile range (IQR) 43.4–83.4) vs 63.0% (IQR 40.3–80.7), P=0.808]. Immunosuppressives were less frequently used among NAb+ patients vs NAb- patients (73.7% vs 100%, P=0.046). Type of SAMs, disease status, other drugs or comorbidities did not influence immunogenicity. Vaccine-related adverse events were mild with similar frequencies in patients and CTRL (P>0.05).

Conclusion

Sinovac-CoronaVac is safe and has a moderate short-term immunogenicity in SAMs, but reduced compared with CTRL. We further identified that immunosuppression is associated with diminished NAb positivity.

Trial registration

COVID-19 CoronaVac in Patients With Autoimmune Rheumatic Diseases and HIV/AIDS (CoronavRheum), http://clinicaltrials.gov/ct2/show/NCT04754698

Anti-Ku Antibody-Positive Myositis Presenting as a Wide Range of Axial Myopathies and Myocarditis: A Case Report and Review of the Literature

Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases predominantly affecting proximal muscles; paraspinal muscle involvement is relatively rare. Because paraspinal myopathies do not always cause clinically-evident symptoms, the diagnosis of IIMs with axial myopathies can be challenging. Anti-Ku autoantibodies, initially reported in polymyositis/systemic sclerosis overlap syndrome, are myositis-associated antibodies (MAAs) observed in patients with a wide variety of connective tissue diseases (CTDs). Few reports have been published demonstrating predominant axial myopathy in IIM patients with anti-Ku antibodies. Herein, we investigated a previously healthy Japanese woman in her early 70s who presented with Raynaud's phenomenon, back pain, and exertional dyspnea. The creatine kinase (CK) was elevated and antinuclear antibody staining was positive, but myositis-specific antibodies (MSAs) were negative. Magnetic resonance imaging (MRI) revealed myocarditis and a wide range of axial muscle inflammation, including bilateral thoracolumbar paraspinal, infraspinatus, and trapezius muscles. The muscle biopsy was consistent with IIM. In addition, anti-Ku antibody was positive. Administration of prednisolone and tacrolimus quickly alleviated the symptoms and the CK level returned to normal. The diagnosis of IIM was arduous in this case because she did not present with camptocormia, muscle weakness involving the proximal limbs was not apparent, and MSAs were negative. Whether axial myopathy and myocarditis are more prevalent in IIM patients with than without anti-Ku antibodies is uncertain. Clinicians should suspect axial myopathy and MAAs, such as anti-Ku antibodies, especially in patients in whom muscle weakness of the proximal limbs is not noticeable.

Safety of Atorvastatin in Patients With Stable Systemic Autoimmune Myopathies: A Pilot Longitudinal Study

BACKGROUND/OBJECTIVE

Patients with systemic autoimmune myopathies (SAMs) have high prevalence of dyslipidemia and, consequently, possible endothelial dysfunction and vascular stiffness. Our objective was to evaluate the possible benefits on endothelial function and vascular stiffness, as well as adverse effects of atorvastatin in SAMs.

METHODS

A pilot longitudinal, double-blind, randomized, placebo-controlled study was conducted. Twenty-four of 242 patients were randomized at a 2:1 ratio to receive atorvastatin (20 mg/d) or placebo for a period of 12 weeks. Demographic data, comorbidities, and clinical and laboratory parameters, as well as endothelial function and arterial stiffness, were evaluated.

RESULTS

Of the 24 randomized patients, 4 patients were excluded, with remaining 20 patients (14 in the atorvastatin group and 6 in the placebo group). The mean age of the patients was 49.0 years, and 75% of the patients were female. At baseline, the demographic data, disease status, treatment, cardiovascular comorbidities, and risk factors were comparable between the atorvastatin and placebo groups. After 12 weeks of follow-up of atorvastatin therapy, no improvements were observed for endothelial function and arterial stiffness in either group (p > 0.05). As expected, a significant reduction in total and low-density lipoprotein cholesterol levels was observed. During the study, no clinical intercurrences or disease relapses were observed in either group.

CONCLUSIONS

The atorvastatin drug attenuated low-density lipoprotein cholesterol without worsening clinical outcomes in SAMs. No change was observed for endothelial function and arterial stiffness. Additional studies, with long-term follow-up time and different atorvastatin dosage, are needed to corroborate the results of this study.

High YKL-40 serum levels and its expression in the muscle tissues of patients with antisynthetase syndrome

BACKGROUND

The protein chitinase-3-like-1 (YKL-40) is rarely analyzed in patients with myositis. Therefore, we aimed to evaluate YKL-40 serum levels; correlate them with laboratory and clinical parameters, disease status, and treatment schemes; and analyze the YKL-40 expression in the muscle tissues of patients with antisynthetase syndrome (ASSD).

METHODS

This cross-sectional single-center study included 64 adult patients with ASSD who were age-, gender-, and ethnicity-matched to 64 healthy control individuals. Their YKL-40 serum levels were analyzed using the Enzyme-Linked Immunosorbent Assay (ELISA) kit method, while YKL-40 expression in muscle tissues was analyzed using an immunohistochemical technique. Disease status was assessed using the International Myositis Assessment and Clinical Studies Group (IMACS) set scores.

RESULTS

The patients' mean age was 44.8 ± 11.8 years, and median disease duration was 1.5 (0.0-4.0) years. These patients were predominantly female (82.8%) and Caucasian (73.4%). Most patients had stable disease. The median YKL-40 serum level was significantly higher in patients with ASSD when compared to the healthy individuals: 538.4 (363.4-853.1) pg/mL versus 270.0 (201.8-451.9) pg/mL, respectively; P < 0.001. However, YKL-40 serum levels did not correlate with any clinical, laboratory, disease status, or therapeutic parameters (P > 0.050), except tumor necrosis factor alpha (TNF-α) serum levels (Spearman's correlation, rho = 0.382; P = 0.007). YKL-40 was highly expressed by inflammatory cells found in muscle biopsy specimens.

CONCLUSIONS

High YKL-40 serum levels were observed in patients with ASSD and correlated positively with TNF-α serum levels. Moreover, YKL-40 was expressed by the inflammatory cells of the muscle tissue.

Efficacy of aqua-based plyometric exercises in the rehabilitation of patients with juvenile dermatomyositis: A randomized crossover pilot study

BACKGROUND

Patients with juvenile dermatomyositis (JDM) experience muscle weakness, tiredness, and loss of energy, which restrict their abilities in performance of their daily living activities.

OBJECTIVE

To explore the effect of aquatic-based plyometric (Aqua-PLYO) exercises on muscle strength, fatigue, and functional ability in patients with JDM.

METHODS

This was a randomized, single-blind, crossover pilot study that included 16 patients with JDM (age 13.44 ± 2.85 years). They were assigned randomly to receive either the Aqua-PLYO exercises (n = 8) or the standard outpatient care (SoC ; n = 8) first. After a 1-month washout, the treatment was reversed. Lower limb muscle strength, fatigue perception, functional ability, and disease activity were evaluated before and after each treatment period.

RESULTS

Irrespective of the treatment order, the Aqua-PLYO treatment yielded greater improvement in muscle strength (hip flexors and abductors [P < 0.001] or knee flexors [P < 0.001] and extensors [P = 0.0008]), fatigue perception (P < 0.001), functional ability (P = 0.009), and disease activity (P = 0.0001) than the SoC treatment. By using the shortest confidence intervals (100[1-2α]%) of the difference, the average bioequivalence of the Aqua-PLYO and SoC has not been established at P = 0.05, because the upper and lower confidence bounds of all outcomes were not between the acceptance limits. No period or carryover effects were detected in all outcomes.

CONCLUSION

The Aqua-PLYO exercise protocol as implemented in this study is safe, feasible, and well-tolerated in patients with JDM and seemingly useful to help increase muscle strength, reduce fatigue, and enhance functional ability in such a patient population.

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.

Hand-held dynamometry for assessment of muscle strength in patients with inflammatory myopathies

OBJECTIVES

Muscle weakness in idiopathic inflammatory myopathies (IIMs) is conventionally assessed using manual muscle testing (MMT). However, more objective tools must be developed to accurately and reliably quantify muscle strength in myositis patients. Hand-held dynamometry (HHD) is a quantitative, portable device with reported reliability in neuromuscular disorders. Our aim was to assess the reliability, validity and responsiveness of HHD in myositis.

METHODS

Myositis patients [DM, necrotizing myopathy (NM), PM and anti-synthetase syndrome] evaluated at the University of Pittsburgh myositis centre were prospectively enrolled. Each patient was assessed at 0, 3 and 6 months for validated outcome measures of myositis disease activity and physical function. At each visit, muscle strength was assessed using both MMT and HHD (Micro FET2, Hoggan Health Industries, Draper, UT, USA). The reliability, validity and responsiveness of the HHD was assessed using standard statistical methods.

RESULTS

Fifty IIM patients (60% female; mean age 51.6 years; 6 PM, 9 NM, 24 DM and 11 anti-synthetase syndrome) were enrolled. HHD showed strong test-retest intrarater reliability (r = 0.96) and interrater reliability (r = 0.98). HHD correlated significantly with the MMT score (r = 0.48, P = 0.0006) and myositis disease activity and functional measures. Longitudinal analysis showed a significant and strong association between the HHD and MMT as well as 2016 ACR/EULAR myositis response criteria (r = 0.8, P < 0.0001) demonstrating responsiveness. The mean effect size and standardized response mean of HHD was large: 0.95 and 1.03, respectively. MMT had a high ceiling effect compared with HHD.

CONCLUSION

HHD demonstrated strong reliability, construct validity and responsiveness in myositis patients. External validation studies are required to confirm these findings.

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.

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.

Alterations in activin A-myostatin-follistatin system associate with disease activity in inflammatory myopathies

OBJECTIVES

The aim of this study was to investigate the systemic and skeletal muscle levels of atrophy-associated myokines in patients with idiopathic inflammatory myopathies (IIM) and their association with clinical characteristics of myositis.

METHODS

A total of 94 IIM patients and 162 healthy controls were recruited. Of those, 20 IIM patients and 28 healthy controls underwent a muscle biopsy. Circulating concentrations of myostatin, follistatin, activin A and TGF-β1 were assessed by ELISA. The expression of myokines and associated genes involved in the myostatin signalling pathway in muscle tissue was determined by real-time PCR.

RESULTS

We report decreased levels of circulating myostatin (median 1817 vs 2659 pg/ml; P = 0.003) and increased follistatin (1319 vs 1055 pg/ml; P = 0.028) in IIM compared with healthy controls. Activin A levels were also higher in IIM (414 vs 309 pg/ml; P = 0.0005) compared with controls. Myostatin was negatively correlated to muscle disease activity assessed by physician on visual analogue scale (MDA) (r = -0.289, P = 0.015) and positively to manual muscle testing of eight muscles (r = 0.366, P = 0.002). On the other hand, follistatin correlated positively with MDA (r = 0.235, P = 0.047). Gene expression analysis showed higher follistatin (P = 0.003) and myostatin inhibitor follistatin-like 3 protein (FSTL3) (P = 0.008) and lower expression of activin receptor type 1B (ALK4) (P = 0.034), signal transducer SMAD3 (P = 0.023) and atrophy marker atrogin-1 (P = 0.0009) in IIM muscle tissue compared with controls.

CONCLUSION

This study shows lower myostatin and higher follistatin levels in circulation and attenuated expression of myostatin pathway signalling components in skeletal muscle of patients with myositis, a newly emerging pattern of the activin A-myostatin-follistatin system in muscle wasting diseases.

Eccentric Resistance Training Ameliorates Muscle Weakness in a Mouse Model of Idiopathic Inflammatory Myopathies

OBJECTIVE

High-force eccentric contractions (ECCs) have traditionally been excluded from rehabilitation programs that include patients with idiopathic inflammatory myopathies (IIMs) due to unverified fear of causing muscle damage and inflammation. In an IIM animal model that used mice with experimental autoimmune myositis (EAM), we undertook this study to investigate whether ECC training can safely and effectively be used to counteract muscle weakness in IIM.

METHODS

EAM was induced in BALB/c mice by immunization with 3 injections of myosin emulsified in Freund's complete adjuvant. Controls (n = 12) and mice with EAM (n = 12) were exposed to either an acute bout of 100 ECCs or 4 weeks of ECC training (20 ECCs every other day). To induce ECCs, plantar flexor muscles were electrically stimulated while the ankle was forcibly dorsiflexed.

RESULTS

Less cell damage, as assessed by Evans blue dye uptake, was observed in the muscles of mice with EAM, compared to controls, after an acute bout of 100 ECCs (P < 0.05). Maximum Ca²⁺ -activated force was decreased in skinned gastrocnemius muscle fibers from mice with EAM, and this was accompanied by increased expression of endoplasmic reticulum (ER) stress proteins, including Gsp78 and Gsp94 (P < 0.05). ECC training prevented the decrease in force and the increase in ER stress proteins and also enhanced the expression and myofibrillar binding of small heat-shock proteins (HSPs) (P < 0.05), which can stabilize myofibrillar structure and function.

CONCLUSION

ECC training protected against the reduction in myofibrillar force-generating capacity in an IIM mouse model, and this occurred via inhibition of ER stress responses and small HSP-mediated myofibrillar stabilization.

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.

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.

Functional Index-3: A Valid and Reliable Functional Outcome Assessment Measure in Patients With Dermatomyositis and Polymyositis

OBJECTIVE

Patients with dermatomyositis (DM) and polymyositis (PM) have reduced muscle endurance.The aim of this study was to streamline the Functional Index-2 (FI-2) by developing the Functional Index-3 (FI-3) and to evaluate its measurement properties, content and construct validity, and intra- and interrater reliability.

METHODS

A dataset of the previously performed and validated FI-2 (n = 63) was analyzed for internal redundancy, floor, and ceiling effects. The content of the FI-2 was revised into the FI-3. Construct validity and intrarater reliability of FI-3 were tested on 43 DM and PM patients at 2 rheumatology centers. Interrater reliability was tested in 25 patients. The construct validity was compared with the Myositis Activities Profile (MAP), Health Assessment Questionnaire (HAQ), and Borg CR-10 using Spearman correlation coefficient.

RESULTS

Spearman correlation coefficients of 63 patients performing FI-3 revealed moderate to high correlations between shoulder flexion and hip flexion tasks and similar correlations with MAP and HAQ scores; there were lower correlations for neck flexion task. All FI-3 tasks had very low to moderate correlations with the Borg scale. Intraclass correlation coefficients (ICC) of FI-3 tasks for intrarater reliability (n = 25) were moderate to good (0.88-0.98). ICC of FI-3 tasks for interrater reliability (n = 17) were fair to good (range 0.83-0.96).

CONCLUSION

The FI-3 is an efficient and valid method for clinically assessing muscle endurance in DM and PM patients. FI-3 construct validity is supported by the significant correlations between functional tasks and the MAP, HAQ, and Borg CR-10 scores.

Functional and Structural Adaptations of Skeletal Muscle in Long-Term Juvenile Dermatomyositis: A Controlled Cross-Sectional Study

OBJECTIVE

To compare muscle strength and endurance of the knee extensors between patients with long-term juvenile dermatomyositis (DM) and controls and between patients with active disease and those with inactive disease, and to explore associations between strength/endurance and 1) clinical parameters, 2) physical activity, and 3) humoral/structural adaptation in the skeletal muscle of patients.

METHODS

In a cross-sectional study (44 patients and 44 age- and sex-matched controls), we tested isometric muscle strength (peak torque, in Nm) and dynamic muscle endurance (total work, in Joules) of the knee extensors, physical activity (measured by accelerometer), and serum myokine levels (by enzyme-linked immunosorbent assay). Patients were examined with validated tools (clinical muscle tests and measures of disease activity/damage and inactive disease) and using magnetic resonance imaging of the thigh muscles, which included evaluation of the quadriceps cross-sectional area (CSA). Needle biopsy samples of the vastus lateralis muscle (obtained from 12 patients ages ≥18 years) were assessed by histochemistry.

RESULTS

After a mean ± SD disease duration of 21.8 ± 11.8 years, peak torque was lower in patients with juvenile DM compared to controls (mean difference 29 Nm, 95% confidence interval 13-46; P = 0.001). Similarly, total work of the knee extensors was lower in patients compared to controls (median 738J [interquartile range 565-1,155] versus 1,249J [interquartile range 815-1,665]; P < 0.001). Both peak torque and total work were lower in patients with active juvenile DM compared to those with inactive disease (both P < 0.019); in analyses controlled for quadriceps CSA, only total work remained lower in patients with active disease. Moreover, peak torque and total work correlated with findings from clinical muscle tests in patients with active disease (r = 0.57-0.84). Muscle biopsy results indicated that the fiber type composition was different, but capillary density was similar, between patients with active disease and those with inactive disease.

CONCLUSION

In patients with long-term juvenile DM, both muscle strength and endurance of the knee extensors were lower when compared to matched controls, and also lower in patients with active disease compared to those with inactive disease. Our results indicate a need for more sensitive muscle tests in this clinical setting. We hypothesize that impaired muscle endurance in patients with active juvenile DM may be influenced by structural/functional adaptations of muscle tissue independent of muscle size.

A review of accelerometer-derived physical activity in the idiopathic inflammatory myopathies

Background

The idiopathic inflammatory myopathies (IIMs) are a group of rare conditions characterised by muscle inflammation (myositis). Accurate disease activity assessment is vital in both clinical and research settings, however, current available methods lack ability to quantify associated variation of physical activity, an important consequence of myositis.

This study aims to review studies that have collected accelerometer-derived physical activity data in IIM populations, and to investigate if these studies identified associations between physical and myositis disease activity.

Methods

A narrative review was conducted to identify original articles that have collected accelerometer-derived physical activity data in IIM populations. The following databases were searched from February 2000 until February 2019: Medline via PubMed, Embase via OVID and Scopus.

Results

Of the 297 publications screened, eight studies describing accelerometer use in 181 IIM cases were identified. Seven out of the eight studies investigated juvenile dermatomyositis (JDM) populations and only one reported on an adult-onset population. Population sizes, disease duration, accelerometer devices used, body placement sites, and study duration varied between each study.

Accelerometer-derived physical activity levels were reduced in IIM cohorts, compared to healthy controls, and studies reported improvement of physical activity levels following exercise programme interventions, thus demonstrating efficacy.

Higher levels of accelerometer-derived physical activity measurements were associated with shorter JDM disease duration, current glucocorticoid use and lower serum creatine kinase. However, no clear association between muscle strength and accelerometer-derived physical activity measures was identified.

Conclusions

The use of accelerometer-derived physical activity in IIM research is in its infancy. Whilst knowledge is currently limited to small studies, the opportunities are promising and future research in this area has the potential to improve disease activity assessment for clinical and research applications.

Pediatric rheumatologic diseases: A review for primary care NPs

Rheumatologic diseases are uncommon in children but have the potential for significant morbidity, mortality, and disability. This article reviews the most common rheumatologic diseases in children, their diagnostic evaluations, and the NP's role in the management and coordination of these conditions.

Idiopathic inflammatory myopathy comorbid with Sturge-Weber syndrome: a case report

Background

Sturge-Weber syndrome (SWS) is a rare and sporadic congenital neurocutaneous disorder, that is characterized by facial venous capillary malformation (port-wine birthmark), leptomeningeal venous malformation (angiomatosis), glaucoma, and neurologic problems. SWS can comorbid with other disorders in some patients, however, muscular abnormalities have still not been reported in patients with SWS.

Case presentation

A forty-one-year-old Chinese female who had left side port-wine stain, ipsilateral glaucoma, and hypothyroidism was included in the present study. The neurocutaneous and endocrine symptoms were consistent with the SWS diagnostic criteria. Meanwhile, the patient had progressive weakness on her both arms and legs, dramatically elevated creatine kinase (CK) and myoglobin levels, and elevated antinuclear and anti-Ro52 antibodies. Intravenous methylprednisolone (MP) (80 mg/d), methotrexate, and intravenous cyclophosphamide were administrated and the weakness of the patient was gradually relieved with normal serum CK level.

Conclusions

We reported the first case of SWS comorbid with inflammatory myopathy. The underlying mechanism for SWS and idiopathic inflammatory myopathy is still not clear, and further researches need to be conducted to deeply explore the mentioned mechanism.

Whole-body MRI and pathological findings in adult patients with myopathies

Magnetic resonance imaging (MRI) is considered the most sensitive and specific imaging technique for the detection of muscle diseases related to myopathies. Since 2008, the use of whole-body MRI (WBMRI) to evaluate myopathies has improved due to technical advances such as rolling table platform and parallel imaging, which enable rapid assessment of the entire musculoskeletal system with high-quality images. WBMRI protocols should include T1-weighted and short-tau inversion recovery (STIR), which provide the basic pulse sequences for studying myopathies, in order to detect fatty infiltration/muscle atrophy and muscle edema, respectively. High signal intensity in T1-weighted images shows chronic disease with fatty infiltration, whereas high signal intensity in STIR indicates an acute stage with muscle edema. Additional sequences such as diffusion-weighted imaging (DWI) can be readily incorporated into routine WBMRI study protocols. Contrast-enhanced sequences have not been done. This article reviews WBMRI as an imaging method to evaluate different myopathies (idiopathic inflammatory, dystrophic, non-dystrophic, metabolic, and channelopathies). WBMRI provides a comprehensive estimate of the total burden with a single study, seeking specific distribution patterns, including clinically silent involvement of muscle areas. Furthermore, WBMRI may help to select the "target muscle area" for biopsy during patient follow-up. It may be also be used to detect related and non-related pathological conditions, such as tumors.

Muscle Expression of Type I and Type II Interferons Is Increased in Juvenile Dermatomyositis and Related to Clinical and Histologic Features

OBJECTIVE

To evaluate the expression of type I interferon (IFNα/β)- and type II IFN (IFNγ)-inducible genes in muscle biopsy specimens from patients with juvenile dermatomyositis (DM) and to correlate their expression levels with histologic and clinical features.

METHODS

Expression levels of IFN-inducible genes and proinflammatory cytokines were assessed by quantitative polymerase chain reaction in muscle biopsy specimens from patients with juvenile DM (n = 39), patients with Duchenne's muscular dystrophy (DMD), and healthy controls. Muscle biopsy sections were stained and scored for severity of histopathologic features. The charts of patients with juvenile DM were reviewed for clinical features at the time of sampling and long-term outcomes.

RESULTS

Muscle expression levels of IFNα/β-inducible genes (type I IFN score), IFNγ, IFNγ-inducible genes (type II IFN score), and tumor necrosis factor (TNF) were significantly higher in juvenile DM patients not receiving glucocorticoid therapy before muscle biopsy (n = 27) compared to DMD patients (n = 24) (type I IFN score, P < 0.0001; type II IFN score, P < 0.001; TNF, P < 0.05) and healthy controls (n = 4) (type I IFN score, P < 0.01; type II IFN score, P < 0.01; TNF, P < 0.05). Immunofluorescence staining of muscle biopsy sections from untreated juvenile DM patients showed increased immunoreactivity for IFNγ and HLA class II molecules compared to controls. Type I and type II IFN scores were correlated with typical histopathologic features of juvenile DM muscle biopsy samples, such as infiltration of endomysial CD3+ cells (type I IFN score, r = 0.68; type II IFN score, r = 0.63), perimysial CD3+ cells (type I IFN score, r = 0.59; type II IFN score, r = 0.66), CD68+ cells (type II IFN score, r = 0.46), and perifascicular atrophy (type I IFN score, r = 0.61; type II IFN score, r = 0.77). Juvenile DM patients with a high type I IFN score, a high type II IFN score, and high TNF expression levels showed more severe disease activity at biopsy (P < 0.05). In addition, juvenile DM patients with a high type II IFN score at biopsy reached clinically inactive disease significantly later than patients with low type II IFN score (log rank chi-square value 13.53, P < 0.001).

CONCLUSION

The increased expression of IFN-inducible genes in the muscle in juvenile DM patients and their association with histologic and clinical features further support a pathogenic role for both type I and type II IFNs in juvenile DM.

Mycophenolate mofetil treatment with or without a calcineurin inhibitor in resistant inflammatory myopathy

To evaluate the efficacy and tolerability of mycophenolate mofetil (MMF) with or without calcineurin inhibitors (CNIs) in patients with inflammatory myopathy taking prednisolone, but refractory to conventional immunosuppressive therapy. The records of patients with inflammatory myopathy who had previously failed treatment with at least one immunosuppressant were retrospectively evaluated. We selected patients treated with MMF and divided them into two groups depending on whether or not there was concomitant use of CNIs. We investigated the efficacy by changes in creatine kinase (CK) levels, forced vital capacity (%FVC), prednisolone dose, and high-resolution computed tomography (HRCT) findings. Interstitial lung disease (ILD) progression was defined by more than 10% decline of %FVC from baseline. We identified 19 patients on MMF treatment. There were seven (36.8%) patients on MMF and CNIs, including five on cyclosporine and two on tacrolimus. At baseline, no significant difference was seen in the prevalence of ILD between patients taking or not taking CNIs (85.7% vs. 75.0%, P = 0.68). Improvement in CK was seen in patients treated with CNIs (P = 0.04) but not in those without (P = 0.39). No significant improvement in %FVC and HRCT findings were found in patients with ILD in either group, and there were no differences in death or ILD progression. The combination of CNIs and MMF might be more effective for decreasing CK levels than MMF alone. Neither treatment arm had a beneficial effect on ILD over a variable observation period.

Novel insights of disability assessment in adult myositis

PURPOSE OF REVIEW

To review the novel development of standardized clinical outcome measures used in adult patients with idiopathic inflammatory myopathies (IIMs). A further aim was to determine what aspects of IIM are covered by these outcome measures according to the International Classification of Functioning, Disability and Health (ICF).

RECENT FINDINGS

The sporadic inclusion body myositis functional assessment (sIFA) is the first diagnosis-specific patient-driven patient-reported outcome measure. The adult myositis assessment tool (AMAT) is a new outcome measure assessing physical performance. Also, new criteria to assess response to treatment have been presented for both adults and children with IIM. The ICF provides a standardized frame and structure to report outcome, including functional disability. Using this framework, it is evident that there is a lack of validated patient-reported outcome measures to assess disease aspects important to patient, and that no studies have evaluated life-style factors such as physical activity in these patients.

SUMMARY

The sIFA will ensure patient-relevant patient-reported assessment of activity limitations in patients with inclusion body myositis. The AMAT is a partly validated tool that needs to be used in clinical trials for further validation. The response criteria will enhance assessment of individual response to different treatments.

Update on outcome assessment in myositis

The adult and juvenile myositis syndromes, commonly referred to collectively as idiopathic inflammatory myopathies (IIMs), are systemic autoimmune diseases with the hallmarks of muscle weakness and inflammation. Validated, well-standardized measures to assess disease activity, known as core set measures, were developed by international networks of myositis researchers for use in clinical trials. Composite response criteria using weighted changes in the core set measures of disease activity were developed and validated for adult and juvenile patients with dermatomyositis and adult patients with polymyositis, with different thresholds for minimal, moderate and major improvement in adults and juveniles. Additional measures of muscle strength and function are being validated to improve content validity and sensitivity to change. A health-related quality of life measure, which incorporates patient input, is being developed for adult patients with IIM. Disease state criteria, including criteria for inactive disease and remission, are being used as secondary end points in clinical trials. MRI of muscle and immunological biomarkers are promising approaches to discriminate between disease activity and damage and might provide much-needed objective outcome measures. These advances in the assessment of outcomes for myositis treatment, along with collaborations between international networks, should facilitate further development of new therapies for patients with IIM.

Innovative Research Design to Meet the Challenges of Clinical Trials for Juvenile Dermatomyositis

PURPOSE OF REVIEW

This paper aims to provide a summary of the recent therapeutic advances and the latest research on outcome measures for clinical trials in juvenile dermatomyositis (JDM).

RECENT FINDINGS

Recent randomized controlled trials (RCTs) have demonstrated the superiority of the combination of prednisone with methotrexate over other conventional therapies and the potential effectiveness of rituximab in refractory cases. A multinational project has led to develop new criteria for the definition of minimal, moderate, and major improvement in future JDM clinical trials. This effort has been paralleled by the establishment of criteria for clinically inactive disease. The validation of the first composite disease activity score for JDM is in progress. The new outcome measures will increase the reliability of assessment of clinical response in JDM clinical trials and foster future multinational RCTs aimed to investigate novel treatment strategies for refractory forms of JDM.

Manual muscle testing and hand-held dynamometry in people with inflammatory myopathy: An intra- and interrater reliability and validity study

Manual muscle testing (MMT) and hand-held dynamometry (HHD) are commonly used in people with inflammatory myopathy (IM), but their clinimetric properties have not yet been sufficiently studied. To evaluate the reliability and validity of MMT and HHD, maximum isometric strength was measured in eight muscle groups across three measurement events. To evaluate reliability of HHD, intra-class correlation coefficients (ICC), the standard error of measurements (SEM) and smallest detectable changes (SDC) were calculated. To measure reliability of MMT linear Cohen`s Kappa was computed for single muscle groups and ICC for total score. Additionally, correlations between MMT8 and HHD were evaluated with Spearman Correlation Coefficients. Fifty people with myositis (56±14 years, 76% female) were included in the study. Intra-and interrater reliability of HHD yielded excellent ICCs (0.75–0.97) for all muscle groups, except for interrater reliability of ankle extension (0.61). The corresponding SEMs% ranged from 8 to 28% and the SDCs% from 23 to 65%. MMT8 total score revealed excellent intra-and interrater reliability (ICC>0.9). Intrarater reliability of single muscle groups was substantial for shoulder and hip abduction, elbow and neck flexion, and hip extension (0.64–0.69); moderate for wrist (0.53) and knee extension (0.49) and fair for ankle extension (0.35). Interrater reliability was moderate for neck flexion (0.54) and hip abduction (0.44); fair for shoulder abduction, elbow flexion, wrist and ankle extension (0.20–0.33); and slight for knee extension (0.08). Correlations between the two tests were low for wrist, knee, ankle, and hip extension; moderate for elbow flexion, neck flexion and hip abduction; and good for shoulder abduction. In conclusion, the MMT8 total score is a reliable assessment to consider general muscle weakness in people with myositis but not for single muscle groups. In contrast, our results confirm that HHD can be recommended to evaluate strength of single muscle groups.

Muscle Strength and Muscle Endurance During the First Year of Treatment of Polymyositis and Dermatomyositis: A Prospective Study

Objective.

To investigate muscle impairment (isometric and dynamic) and disease activity during the first year after diagnosis of polymyositis (PM) and dermatomyositis (DM), and to study the relationship between muscle impairment, patient-reported health, and disease activity.

Methods.

Seventy-two patients enrolled in the Swedish Myositis Register, 2003–2010, were followed prospectively. The Manual Muscle test (MMT-8; isometric muscle strength), the Functional Index of myositis test (FI-2; dynamic, repetitive muscle function), and disease activity (6-item core set) were retrieved at the time of diagnosis, and after 6 and 12 months. Self-reported health (Medical Outcomes Study Short Form-36; SF-36) was retrieved at 12 months.

Results.

At the time of diagnosis, median (Q1–Q3) for the FI-2 was 27.2% (7.9–60.5%) of maximal score compared to 93.8% (92.5–98.8%) of maximal MMT-8. At 12 months, the FI-2 and the MMT-8 improved to 29.4% (16.5–60.7%; p < 0.05) and 96.1% (88.1–99.4%), respectively (p < 0.01). At 12 months, 45% of patients improved ≥ 20%, and 27% worsened ≥ 20% in FI-2 score, while 10% improved ≥ 20% in MMT-8. Physician’s global visual analog scale (VAS), Health Assessment Questionnaire, and creatine phosphokinase levels improved significantly at 12 months (p < 0.05–0.001) while patient’s global and extramuscular VAS remained unchanged. The SF-36 physical function correlated strongly with the FI-2 (rs = 0.74; CI 0.55–0.85) and moderately with the MMT (rs = 0.54; CI 0.27–0.73), with lower correlations between muscle function and other SF-36 domains.

Conclusion.

Patients with PM/DM were characterized by impaired dynamic repetitive muscle function (DRMF) that correlated well with patient-reported physical function. Assessment of DRMF adds information regarding muscle impairment in these patients.

Trajectories of cardiorespiratory fitness in patients with juvenile dermatomyositis

Objectives

Previous research demonstrated decreased cardiorespiratory fitness (CRF) in patients with JDM during active disease and remission. However, longitudinal data regarding trajectories of CRF are currently lacking. The objective of this study was to determine trajectories of CRF in patients with both monocyclic and chronic JDM, and to identify potential predictors of these trajectories.

Methods

Thirty-six patients with JDM [median age (interquartile range) at diagnosis: 8.3 (6.3-15.4) years] treated in our paediatric rheumatology outpatient clinic were included. All patients performed multiple cardiopulmonary exercise tests between 2003 and 2016. Relevant CRF parameters were analysed, including peak oxygen uptake, maximal workload, mechanical efficacy and oxygen uptake at ventilatory anaerobic threshold. We analysed trajectories up to 10 years after diagnosis and determined predictors of CRF outcome parameters by multilevel analyses.

Results

Trajectories demonstrated significant declines in CRF during the active phase of the disease with subsequent improvement in CRF during the initial years after diagnosis. However, hereafter no further improvements, and even a decrease, in CRF were observed over time in both monocyclic and chronic subtypes of JDM. We found that a longer disease duration, younger age of onset and higher prednisone dose negatively influence CRF.

Conclusion

Patients with both monocyclic and chronic JDM show decreases in long-term CRF trajectories. Longer disease duration, younger age of onset and higher prednisone dose negatively influence CRF. This study stresses the need for regular evaluation of CRF and implementation of (exercise) interventions to improve CRF in patients with JDM, even in monocyclic patients.

Childhood- versus adult-onset ANCA-associated vasculitides: A nested, matched case-control study from the French Vasculitis Study Group Registry

OBJECTIVE

To investigate differences between childhood-onset ANCA-associated vasculitides (cAAVs) and matched adult-onset controls (aAAVs).

METHODS

cAAV clinical pictures at onset and outcomes were compared to a randomly selected sample of aAAV patients from the French Vasculitis Study Group Registry. Cases and controls were matched for AAV (granulomatosis with polyangiitis [GPA], microscopic polyangiitis [MPA] or eosinophilic granulomatosis with polyangiitis [EGPA]), sex and year of enrollment. Medications, disease activity and damage were prospectively recorded. Kaplan-Meier curves and the log-rank test were used to analyze case-vs.-control differences for predefined outcomes.

RESULTS

Comparing 35 cAAVs (25 GPA, 4 MPA, 6 EGPA) to 151 aAAVs (106 GPA, 17 MPA, 28 EGPA), their respective median follow-up durations were 71 and 64months (P=0.49), and, at baseline, children had less frequent myalgias (P=0.005) and peripheral neuropathy (P<0.001) but were more frequently febrile (P<0.05). Rates of renal involvement were comparable (13 [37%] cAAVs vs. 73 [48%] aAAVs; P=0.31). Initial GPA-associated ischemic abdominal pain and nasal cartilage damage were more common in cAAVs than aAAVs (P<0.05). During follow-up, the cAAV relapse rate was higher (24.5 vs. 18.7 flares per 100 patient-years; P<0.05) and, at last visit, cases had accumulated more damage, mostly ear, nose & throat sequelae (P=0.001), associated with longer maintenance therapy (P=0.03), than aAAV controls. Four (11.4%) cAAV and 13 (8.6%) aAAV patients died (P=0.53).

CONCLUSION

cAAVs are severe diseases, characterized by a higher relapse rate, more accrued damage and longer maintenance therapy than for aAAVs.

A randomized, double-blind, placebo-controlled trial of infliximab in refractory polymyositis and dermatomyositis

OBJECTIVE

To investigate in a pilot study the safety and efficacy of infliximab in patients with refractory dermatomyositis (DM) and polymyositis (PM).

METHODS

A randomized, double-blind, placebo-controlled trial including subjects with active DM or PM. Participants had stable doses of immunosuppressive medication and prednisone (≤0.5mg/kg/day), and exhibited clinical signs of muscle weakness for at least 4 weeks prior to study entry. Participants received infusions of either placebo or infliximab 5mg/kg at 0, 2, 6, and 14 weeks in blinded manner. The primary outcome was a ≥15% manual muscle strength (MMT) improvement at week 16 compared to week 0. The secondary outcome measures were improvement defined by the International Myositis Assessment and Clinical Studies Group (IMACS) criteria. At week 16, responders in each arm had the option of either continuing the same treatment or changing to the non-responder treatment for that study arm. Non-responders in the 5mg/kg infliximab arm were increased to infliximab 7.5mg/kg for weeks 22, 30, and 38. Non-responders in the placebo arm at week 16 received infliximab 5mg/kg at weeks 16, 18, 22, 30, and 38. Outcomes were reassessed at week 40.

RESULTS

Twelve subjects completed the study to week 16. Six of the 12 subjects received infliximab treatment at the dose of 5mg/kg with only one subject meeting the responder criteria at that dose. Of the remaining five subjects on infliximab, three crossed over to the infliximab 7.5mg/kg dose. One of those three subjects responded. All six patients in the placebo arm crossed over to the 5mg/kg dosing regimen after week 16, and two of those responded to infliximab.

CONCLUSIONS

Infliximab therapy for patients with refractory PM and DM was well tolerated and may benefit a subset of patients.

Effect of endurance exercise on microRNAs in myositis skeletal muscle-A randomized controlled study

OBJECTIVE

To identify changes in skeletal muscle microRNA expression after endurance exercise and associate the identified microRNAs with mRNA and protein expression to disease-specific pathways in polymyositis (PM) and dermatomyositis (DM) patients.

METHODS

Following a parallel clinical trial design, patients with probable PM or DM, exercising less than once a week, and on stable medication for at least one month were randomized into two groups at Karolinska University Hospital: a 12-week endurance exercise group (n = 12) or a non-exercised control group (n = 11). Using an Affymetrix microarray, microRNA expression was determined in paired muscle biopsies taken before and after the exercise intervention from 3 patients in each group. Ingenuity pathway analysis with a microRNA target filter was used to identify microRNA transcript targets. These targets were investigated at the mRNA (microarray) and protein (mass spectrometry) levels in patients.

RESULTS

Endurance exercise altered 39 microRNAs. The microRNAs with increased expression were predicted to target transcripts involved in inflammatory processes, metabolism, and muscle atrophy. Further, these target transcripts had an associated decrease in mRNA expression in exercised patients. In particular, a decrease in the NF-κB regulator IKBKB was associated with an increase in its target microRNA (miR-196b). At the protein level, there was an increase in mitochondrial proteins (AK3, HIBADH), which were associated with a decrease in microRNAs that were predicted to regulate their expression.

CONCLUSION

Improvement in disease phenotype after exercise is associated with increasing microRNAs that target and downregulate immune processes at the transcript level, as well as decreasing microRNAs that target and upregulate mitochondrial content at the protein level. Therefore, microRNAs may improve disease by decreasing immune responses and increasing mitochondrial biogenesis.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01184625.

Immune Mediated Necrotizing Myopathy: a Cause of Isolated Myopathy of Neck Extensor Muscle

Immune mediated necrotizing myopathy (IMNM) is a unique form of myositis that is characterized by distinct muscle biopsy features including abundant myofiber necrosis, degeneration, and regeneration with only minimal, if any, inflammation on muscle biopsy. IMNM is clinically similar to idiopathic inflammatory myopathy (IIM); hence, muscle biopsy is essential to diagnose IMNM. Herein we describe a case of neck extensor weakness due to necrotizing myopathy. Isolated weakness of the neck extensor muscles is uncommon in IIM and IMNM. This case describes the diagnostic work-up, treatments utilized, and 2 year follow-up course without involvement of other muscle groups and without progression of neck extensor muscle weakness. Advanced imaging using magnetic resonance imaging (MRI) facilitated the diagnosis by identifying the affected muscles and site for muscle biopsy.

Comparative Long-Term Evaluation of Patients With Juvenile Inflammatory Myopathies

OBJECTIVES

We conducted a retrospective study analyzing the clinical features, laboratory findings, demographics, and long-term prognoses of patients with juvenile inflammatory myopathies to determine possible predictors indicating the use of aggressive immunotherapy and the response to and complications of treatment.

METHODS

The medical records of 41 patients with juvenile inflammatory myopathies seen at University of Tennessee-affiliated hospitals in Memphis from 1969 to 2008 were evaluated. Patients' clinical characteristics, laboratory studies, muscle biopsies, and electromyography were reviewed. All patients were treated with prednisone initially; additionally, 14 patients received varying combinations of other immunosuppressant therapies.

RESULTS

Seventy-three percent of the patients experienced remission. Patients in the group that did not go into remission had specific characteristics at onset: they were comparatively older and had more severe rashes, contractures, arthritis, and systemic involvement. Also, patients with positive autoantibodies (antinuclear antibody, rheumatoid arthritis factor) had better outcomes.

CONCLUSIONS

Juvenile inflammatory myopathies have relatively good prognoses. Initial presentation at advanced age or with severe rash, systemic vasculopathies, anemia, or arthritis portends refractory disease; in these patients, second- and third-line therapies improve outcome.

Consensus-based recommendations for the management of juvenile dermatomyositis

Background

In 2012, a European initiative called Single Hub and Access point for pediatric Rheumatology in Europe (SHARE) was launched to optimise and disseminate diagnostic and management regimens in Europe for children and young adults with rheumatic diseases. Juvenile dermatomyositis (JDM) is a rare disease within the group of paediatric rheumatic diseases (PRDs) and can lead to significant morbidity. Evidence-based guidelines are sparse and management is mostly based on physicians' experience. Consequently, treatment regimens differ throughout Europe.

Objectives

To provide recommendations for diagnosis and treatment of JDM.

Methods

Recommendations were developed by an evidence-informed consensus process using the European League Against Rheumatism standard operating procedures. A committee was constituted, consisting of 19 experienced paediatric rheumatologists and 2 experts in paediatric exercise physiology and physical therapy, mainly from Europe. Recommendations derived from a validated systematic literature review were evaluated by an online survey and subsequently discussed at two consensus meetings using nominal group technique. Recommendations were accepted if >80% agreement was reached.

Results

In total, 7 overarching principles, 33 recommendations on diagnosis and 19 recommendations on therapy were accepted with >80% agreement among experts. Topics covered include assessment of skin, muscle and major organ involvement and suggested treatment pathways.

Conclusions

The SHARE initiative aims to identify best practices for treatment of patients suffering from PRD. Within this remit, recommendations for the diagnosis and treatment of JDM have been formulated by an evidence-informed consensus process to produce a standard of care for patients with JDM throughout Europe.

Altered mean platelet volume in patients with polymyositis and its association with disease severity

Polymyositis (PM) is an autoimmune disease characterized by chronic inflammation in skeletal muscle. Mean platelet volume (MPV), a marker in the assessment of systemic inflammation, is easily measured by automatic blood count equipment. However, to our knowledge, there are no data in the literature with respect to MPV levels in PM patients. Therefore, in this study we aimed to investigate MPV levels in patients with PM. This study included 92 newly diagnosed PM patients and 100 healthy individuals. MPV levels were found to be significantly lower compared with healthy controls (10.3±1.23 vs 11.5±0.74 fL, P<0.001). Interestingly, MPV was found to be positively correlated with manual muscle test (MMT) score and negatively correlated with erythrocyte sedimentation rate (ESR) in patients with PM (r=0.239, P=0.022; r=-0.268, P=0.010, respectively). In addition, MPV was significantly lower in active PM patients compared with inactive PM patients (9.9±1.39 vs 10.6±0.92 fL, P=0.010). MPV was independently associated with PM in multivariate regression analyses, when controlling for hemoglobin and ESR (OR=0.312, P=0.031, 95%CI=0.108 to 0.899). The ROC curve analysis for MPV in estimating PM patients resulted in an area under the curve of 0.800, with sensitivity of 75.0% and specificity of 67.4%. Our results suggest that MPV is inversely correlated with disease activity in patients with PM. MPV might be a useful tool for rapid assessment of disease severity in PM patients.