暂无摘要。

OBJECTIVE: Idiopathic Inflammatory Myopathies (IIM) are rare and characterized by heterogeneous manifestations and clinical trajectories. Utilizing tele-research methods has the potential to improve participant recruitment and advance the understanding of the disease. We aimed to evaluate disease characteristics in IIM patients throughout the U.S. and compare these parameters between patients recruited remotely through mobile application or website vs those recruited locally in myositis clinics.
METHODS: \"Myositis Patient Centered Tele-Research\" (My PACER) is a multicentre prospective observational study of U.S. IIM subjects, competitively recruited through traditional in-person clinic visits (Center-Based Cohort [CBC]), and remotely using mobile application or website and social media (Tele-Research Cohort [TRC]). Data collection comprised baseline demographic and clinical variables, encompassing symptoms, organ involvement, diagnostic tests results and medication use.
RESULTS: The study included 120 IIM patients, 82 in the TRC and 38 in the CBC. The average age was 55 ± 13.4, 75% females and 81% Caucasians. Both cohorts exhibited similar demographic characteristics. Overall, 41% dermatomyositis, 27% polymyositis, 23% anti-synthetase syndrome, and 9% necrotizing myositis patients were enrolled, with comparable subtypes prevalence among cohorts (p= 0.85). The groups demonstrated similarities in multiple clinical factors, including muscle enzymes, diagnostic delay, employment status, various patient and physician-reported outcomes, functional tests, and the frequency of abnormal findings in chest CT, pulmonary function tests, and electromyography. TRC patients received biologics and csDMARDs more frequently (p< 0.001 and p= 0.013, respectively).
CONCLUSIONS: Tele-research recruitment yielded a patient cohort resembling traditionally recruited patients demographically and clinically, indicating its effectiveness for robust and diverse patient recruitment in clinical studies.

OBJECTIVE: Our aim was to assess efficacy and safety of Rituximab (RTX) in patients with refractory Idiopathic inflammatory myopathies (IIM) from a monocentric cohort. Thereafter, we evaluated the efficacy of a low-dose RTX regimen as a remission-maintenance therapy.
METHODS: We retrospectively evaluated a cohort of patients affected with IIM treated with RTX. All patients were refractory to glucocorticoids (GC) and at least one immunosuppressant. Two infusions of 1 g two weeks apart were considered as standard cycle of RTX, a single dose of 1 g every six months was deemed as a low-dose RTX regimen. Complete and partial response were defined according to physician\'s judgment, laboratory and radiological features.
RESULTS: Thirty-six patients affected with IIM were enrolled. Eighteen patients (50%) required the use of RTX for muscular involvement, 6 (16.7%) for interstitial lung disease (ILD), 12 (33.3%) for both myositis and ILD. We observed complete response to RTX in 25 patients (69.4%), partial response in 7 (19.4%) and no response in 4 (11.1%), with an overall response of 88.8% (partial and complete response). From the subgroup of twenty-five patients that achieved a complete response, six were treated with a low dose maintenance therapy maintaining a complete response to RTX. Twenty-six patients who achieved a complete or partial response were able to decrease the mean daily GC dose. Infections were the major adverse events detected in our study.
CONCLUSIONS: RTX shows favorable outcomes in refractory patients with IIM. A low-dose regimen of RTX appears to be effective in maintaining remission after induction with standard dose. Key Points • The precise pathogenic mechanism of idiopathic inflammatory myopathies (IIM) remains elusive; however, a growing body of data support the autoimmune hypothesis. In this context, rituximab, a B cell-depleting agent, has emerged as a second-line therapeutic option in IIM. • Several studies have assessed It its effectiveness in refractory IIM patients. • Limited information exists on the use of Rituximab as maintenance therapy in patients who have achieved remission following induction therapy with Rituximab.

OBJECTIVE: To study the trajectories of changes in damage over time and explore associations with autoantibody defined subgroups using a large international cohort of patients with idiopathic inflammatory myopathies (IIM).
METHODS: Data from the MYONET registry, including patients who were tested for autoantibodies and had at least one assessment of damage using the Myositis Damage Index (MDI), were analyzed. Patients were sub-grouped according to their autoantibody profiles (myositis-specific, myositis-associated, or seronegative). The index date was defined as the time point for the first registered MDI assessment. The longitudinal trajectories of damage with autoantibody status as the main predictor were analyzed using linear mixed models.
RESULTS: A total of 757 adult patients were included in this study. Each year of disease duration since diagnosis had an estimated MDI score increase of 0.16 units for the seronegative group (reference). Compared with the seronegative group as reference, patients with dermatomyositis-specific autoantibodies developed less damage per year of follow-up since diagnosis (average 0.08 less score, P = 0.04), whereas patients with anti-PM/Scl autoantibodies developed more damage per year of follow-up since diagnosis (average 0.28 higher score, P = 0.03) independent of sex and age at diagnosis. The seronegative subgroup and the immune-mediated necrotizing myopathy autoantibody subgroup had the strongest correlation between severity of muscle damage and HAQ-DI scores at five years of follow-up, rho=0.84, P < 0.001 and rho=0.72, P < 0.001, respectively.
CONCLUSIONS: Our study is the first to describe patterns and trajectories of change in damage over time in relation to autoantibody defined subgroups in a large international multicenter cohort of patients with IIM. Patients with anti-PM/Scl scored a greater extent of damage, whereas patients with dermatomyositis-specific antibodies had less damage than seronegative patients. Severity in muscle damage had moderate to strong correlation with functional disability among the IMNM and seronegative subgroups with lower correlations for the other subgroups. These findings suggest that autoantibodies may be useful predictors of long-term damage.

Mitochondria form a dynamic network within skeletal muscle. This network is not only responsible for producing adenosine triphosphate (ATP) through oxidative phosphorylation, but also responds through fission, fusion and mitophagy to various factors, such as increased energy demands, oxidative stress, inflammation, and calcium dysregulation. Mitochondrial dysfunction in skeletal muscle not only occurs in primary mitochondrial myopathies, but also other hereditary and acquired myopathies. As such, this review attempts to highlight the clinical and histopathologic aspects of mitochondrial dysfunction seen in hereditary and acquired myopathies, as well as discuss potential mechanisms leading to mitochondrial dysfunction and therapies to restore mitochondrial function.

Background Despite the increasing use of wearable devices worldwide, concise data on these instruments in patients with systemic autoimmune rheumatic diseases, including idiopathic inflammatory myopathies (IIM) and primary systemic vasculitis (PSV), are lacking. Objectives The aim of this study is to investigate the knowledge and use of wearable devices and to assess their impact on the general quality of life of patients with IIM and PSV. Moreover, we compared these characteristics between patients with IIM and PSV users and non-users of wearable devices. Methods This single-center, cross-sectional study was conducted between January 2023 and June 2023. We included adult patients with IIM and PSV and a control group (CTR) and evaluated their use of cell phones and wearables, level of physical activity, and quality of life. Results A total of 132 patients with IIM, 82 with PSV, and 178 in the CTR were evaluated. Overall, 169 patients and 144 in the CTR were aware of wearable devices, of whom 50 (29.6%) and 47 (32.6%), respectively, had already used this technology. In addition, the IPAQ-Mets and EQ-5D scores were lower in the IIM and PSV groups than in the CTR, and the fatigue severity scale (FSS) scores were higher in the IIM and PSV groups than in the CTR. Patients who used the devices showed FSS scores of 29 (18-40) points, with higher levels of IPAQ-Mets among device users, indicating greater physical activity than among nonusers. Conclusion Based on the results, the use of wearable devices is associated with better fatigue and IPAQ scores. Possibly, the use of such devices can have an impact on better lifestyle habits among these patients.

Idiopathic Inflammatory Myopathies are rare conditions with several heterogeneous disease subtypes. They can range from limited muscle or skin involvement to severe, systemic, life-threatening disease. Although the etiology is unknown, some evidence suggests a role for external agents, particularly drugs. Herein, we present a case of a 71-year-old woman with chronic myeloid leukemia who developed imatinib-induced dermatomyositis sine dermatitis. The presentation was predominantly muscular, characterized by proximal muscle weakness and myalgia of the lower limbs, with positive anti-Mi2a antibodies. Spontaneous recovery was observed after drug discontinuation, without the need for immunosuppressive therapy. This is the first confirmed description of an imatinib-induced dermatomyositis sine dermatitis. It reflects the importance of a high awareness from rheumatologists and hematologists to accurately anticipate and identify similar situations.

暂无摘要。

UNASSIGNED: Inclusion body myositis (IBM) is a progressive late-onset muscle disease characterised by preferential weakness of quadriceps femoris and finger flexors, with elusive causes involving immune, degenerative, genetic and age-related factors. Overlapping with normal muscle ageing makes diagnosis and prognosis problematic.
UNASSIGNED: We characterised peripheral blood leucocytes in 81 IBM patients and 45 healthy controls using flow cytometry. Using a random forest classifier, we identified immune changes in IBM compared to HC. K-means clustering and the random forest one-versus-rest model classified patients into three immunophenotypic clusters. Functional outcome measures including mTUG, 2MWT, IBM-FRS, EAT-10, knee extension and grip strength were assessed across clusters.
UNASSIGNED: The random forest model achieved a 94% AUC ROC with 82.76% specificity and 100% sensitivity. Significant differences were found in IBM patients, including increased CD8+ T-bet+ cells, CD4+ T cells skewed towards a Th1 phenotype and altered γδ T cell repertoire with a reduced proportion of Vγ9+Vδ2+ cells. IBM patients formed three clusters: (i) activated and inflammatory CD8+ and CD4+ T-cell profile and the highest proportion of anti-cN1A-positive patients in cluster 1; (ii) limited inflammation in cluster 2; (iii) highly differentiated, pro-inflammatory T-cell profile in cluster 3. Additionally, no significant differences in patients\' age and gender were detected between immunophenotype clusters; however, worsening trends were detected with several functional outcomes.
UNASSIGNED: These findings unveil distinct immune profiles in IBM, shedding light on underlying pathological mechanisms for potential immunoregulatory therapeutic development.

OBJECTIVE: To assess the ability of dual-energy X-ray absorptiometry (DXA) and hand-grip dynamometer to measure damage in inflammatory myopathies (IM).
METHODS: Forty adult IM patients with a disease duration ≥12 months, low or no disease activity for ≥6 months, were prospectively enrolled. Thirty healthy age and sex-matched volunteers were enrolled as controls. Whole-body DXA and hand-grip dynamometer were used to measure muscle mass, grip strength and diagnose sarcopenia (EWGSOP2 criteria). Relationships between the results of strength in 12 muscles, functional tests, patient-reported disability, IMACS damage score, and history of the disease were assessed. The serum levels of potential molecular actors in the damage were measured.
RESULTS: DXA and grip strength measurements took ≤20 min. Both muscle mass and grip strength were decreased in IM patients vs volunteers (-10% and -30%, respectively) with a dispersion that varied widely (interquartile range -24.3% to +7.8% and -51.3% to -18.9%, respectively). Muscle mass and grip strength were non-redundantly correlated (r up to 0.6, P = 0.0001) with strength in 14 muscles (manual muscle test and hand-held dynamometer), functions (of limbs, respiratory and deglutition muscles), patient-reported disability, damage (extension and severity in muscular and extra-muscular domains) and blood levels of several myokines. Seven IM patients (17.5%) were sarcopenic. They had the worst damage, impaired functions, disability and history of severe myopathy. Decreased irisin and osteonectin levels were associated with sarcopenia (area under the curve 0.71 and 0.80, respectively).
CONCLUSIONS: DXA and hand-grip dynamometer are useful tools to assess damage in IM. Irisin and osteonectin may play a role in IM damage pathogenesis.