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

OBJECTIVE: Idiopathic inflammatory myopathy (IIM) with antimitochondrial M2 antibody (AMA-M2) has been associated with distinct clinical characteristics. In this study, we explore the magnetic resonance imaging (MRI) findings of the muscles of the lower extremities in AMA-M2-positive IIM to gain more insight. METHODS: MRI of 22 lower extremity muscles was retrospectively evaluated in 14 patients with AMA-M2-positive IIM and 37 age- and sex-matched patients with AMA-M2-negative IIM. Muscles with inflammatory edema and fatty infiltration were assessed according to the Stramare and Mercuri criteria. RESULTS: Patients with AMA-M2-positive IIM had significantly higher incidence of MRI involvement with fatty infiltration in five lower extremity muscles, namely the adductor magnus (AM) (13/14 VS 14/37, p < 0.001), semimembranosus (SM) (13/14 VS 17/37, p = 0.002), biceps femoris (BF) (12/14 VS 15/37, p = 0.004), soleus (13/14 VS 23/37, p = 0.041), and the medial head of the gastrocnemius (Gastroc M) (13/14 VS 17/37, p = 0.002) than patients with AMA-M2-negative IIM. Furthermore, the severity scores of fatty infiltrations of the above five muscles in AMA-M2-positive IIM were significantly higher than those in patients with AMA-M2-negative IIM (p < 0.001). CONCLUSIONS: Severe fatty infiltrations of the AM, SM, BF, soleus, and Gastroc M in the posterior muscles of the lower extremities are dominant MRI features in our patients with AMA-M2-positive IIM. This unique muscle MRI character may be a helpful indicator in clinical practice for patients with AMA-M2-positive IIM. Key Points • Striking involvement and prominent fatty infiltrations of five lower extremity muscles (adductor magnus, semimembranosus, biceps femoris, soleus, and the medial head of the gastrocnemius) are interesting MRI performances. • Severe fatty infiltrations in the posterior muscles of the lower extremities are dominant MRI features in AMA-M2-positive IIM. • This unique muscle MRI character may be very helpful for the diagnosis of the AMA-M2-positive IIM.

Adversarial Defense Method Based on Latent Representation Guidance for Remote Sensing Image Scene Classification.

Deep neural networks have made great achievements in remote sensing image analyses; however, previous studies have shown that deep neural networks exhibit incredible vulnerability to adversarial examples, which raises concerns about regional safety and production safety. In this paper, we propose an adversarial denoising method based on latent representation guidance for remote sensing image scene classification. In the training phase, we train a variational autoencoder to reconstruct the data using only the clean dataset. At test time, we first calculate the normalized mutual information between the reconstructed image using the variational autoencoder and the reference image as denoised by a discrete cosine transform. The reconstructed image is selectively utilized according to the result of the image quality assessment. Then, the latent representation of the current image is iteratively updated according to the reconstruction loss so as to gradually eliminate the influence of adversarial noise. Because the training of the denoiser only involves clean data, the proposed method is more robust against unknown adversarial noise. Experimental results on the scene classification dataset show the effectiveness of the proposed method. Furthermore, the method achieves better robust accuracy compared with state-of-the-art adversarial defense methods in image classification tasks.

Efficacy and Safety of Tofacitinib in Anti-Melanoma Differentiation-Associated 5 Gene Antibody-Positive Dermatomyositis.

OBJECTIVES: This study aimed to evaluate the efficacy and safety of tofacitinib for the treatment of anti-melanoma differentiation-associated 5 gene (anti-MDA5) antibody-positive dermatomyositis (DM). METHODS: This study included 52 patients with anti-MDA5 antibody-positive DM (MDA5 + DM) who were treated with tofacitinib and followed up. Clinical and laboratory data of these patients were recorded between January 2019 and June 2022. SPSS was used for all statistical analyses. RESULTS: The mean age of patients with MDA5 + DM was 45 ± 12.4 years, and the median disease duration was 6.5 months (range, 3-13 months). The mean dosage of glucocorticoids was 34.7 ± 20.9 mg/d at the initiation of tofacitinib therapy. Overall, 47 patients were followed up for a mean duration of 7.8 ± 6.2 months. We found that the clinical symptoms of 28 patients (59.6%) were improved, but 1 patient (2.1%) died because of severe infection. Moreover, complications occurred in 25 patients (53.2%), among whom 19 patients had infections. Older age and C-reactive protein levels close to the upper value in reference range at the initial treatment were found to be the potential risk factors of infection. Furthermore, patients with cutaneous ulcers were found to have a lower risk of infection. CONCLUSION: Tofacitinib can be used as a potential therapeutic option for MDA5 + DM. The occurrence of infection requires special attention during treatment, particularly in patients with older age and C-reactive protein levels close to the upper value in reference range.

Clinical role of bronchoalveolar lavage in dermatomyositis-associated interstitial lung disease.

OBJECTIVE: To investigate the role of bronchoalveolar lavage (BAL) in DM-associated interstitial lung disease (ILD). METHODS: We retrospectively reviewed the medical records of patients with DM-ILD who underwent bronchoscopy between October 2015 and September 2019. We then collated clinical features, laboratory data and bronchoscopy findings. The follow-up study was terminated on the 1 May 2020. RESULTS: A total of 113 DM-ILD patients were included in this study, including 27 patients with acute/subacute interstitial pneumonia (A/SIP) and 86 patients with chronic interstitial pneumonia (CIP). The A/SIP group had significantly lower proportions of lymphocytes and eosinophils in the bronchoalveolar lavage fluid (BALF) than the CIP group, but had a significantly higher proportion of neutrophils. Pathogens were discovered in BALF from 28 (24.8%) patients. Twenty-five (22.1%) patients commenced or changed antibiotic therapy on the basis of their bronchoscopy results. Lymphopenia and intensive care unit care were significantly associated with pathogen-positive BALF findings. Complications of bronchoscopy occurred in nine (8.0%) patients; fever (5.3%) was the most common complication. Twenty-five deaths (25/106, 23.6%) were observed during a mean follow-up of 22 months. Age, A/SIP and anti-MDA5 antibody were identified as independent predictors of a poor outcome, while mechanic's hands was an independent protective factor. However, cellular and pathogen findings in BALF had no significant influence on 30-day or overall mortality. CONCLUSION: Bronchoscopy is a relatively useful instrument to evaluate ILD in patients with DM, and BAL can improve the diagnosis of infection. However, cellular and pathogen findings from BALF had no significant influence on prognosis.

The effects of infliximab in treating idiopathic inflammatory myopathies: A review article.

Anti-TNF treatment may be useful for patients with idiopathic inflammatory myopathies (IIMs). The purpose of this study is to assess the efficacy of infliximab (IFX) in the management of IIMs. Two databases (ie, PubMed and China National Knowledge Infrastructure) were searched up to Nov 2020 for studies investigating skin lesions and muscular weakness in patients with IIMs treated with IFX. A total of 18 studies were included. One hundred and eighteen patients were identified, including 58 adult patients and 60 patients with juvenile dermatomyositis (JDM) treated with IFX. Among these patients, 110 (93%) patients with refractory cases. In addition to glucocorticoids, patients from 15/18 studies received immunosuppressant agents (ISAs) concomitantly with IFX, among which methotrexate (MTX) was most common. After treatment with IFX, skin lesions and muscle strength were improved in 67% of patients with DM and 75% of patients with JDM, respectively. Skin calcinosis was improved in 21/34 (62%) of patients with JDM. Only 55% (12/22) of patients with polymyositis exhibited improvements in muscle strength. Lastly, 40% (42/104) of patients reported adverse events. Current evidence appears to support the use of IFX in some patients with refractory IIMs, especially those with JDM. The most common adverse reaction was infection. Large, randomized-controlled studies should be carried out to confirm these findings.

The Efficacy of Tocilizumab in the Treatment of Patients with Refractory Immune-Mediated Necrotizing Myopathies: An Open-Label Pilot Study.

Objective: To evaluate the efficacy of tocilizumab (TCZ) in adult patients with refractory immune-mediated necrotizing myopathies (IMNMs) and investigate possible predictive biomarkers of the response to treatment with TCZ. Methods: Patients with refractory IMNM were enrolled in this open-label pilot observational study and received intravenous TCZ treatment. The clinical response was assessed after 6 months of TCZ treatment according to the 2016 American College of Rheumatology-European League Against Rheumatism (ACR-EULAR) response criteria for adult dermatomyositis and polymyositis. Muscle biopsies were performed to investigate muscle fiber regeneration by immunohistochemical staining of CD56. Serum levels of interleukin (IL)-6 were measured using a multiplex bead-based flow fluorescent immunoassay. The levels of muscle IL-6 mRNA were detected by real-time polymerase chain reaction. Results: A total of 11 patients with refractory IMNM were enrolled in the study, including 3 anti-3-hydroxy-3-methylglutaryl-CoA reductase- and 8 anti-signal recognition particle-positive patients. Seven (63.6%) of these patients achieved clinically significant responses according to the 2016 ACR-EULAR myositis response criteria. Responders had higher baseline serum IL-6 and muscle IL-6 mRNA levels and percentage of CD56-positive muscle fibers than non-responders. Baseline serum IL-6 levels and the percentage of CD56-positive muscle fibers were positively correlated with total improvement score after 6 months of TCZ treatment. Furthermore, muscle fiber necrosis and muscle fiber size variation decreased in repeated muscle biopsies in five responders. Conclusion: Patients with refractory IMNM may respond to TCZ. Baseline serum IL-6 and muscle IL-6 mRNA levels and the percentage of CD56-positive muscle fibers may predict the response to TCZ treatment in these patients.

Clinical features, treatments and outcomes of calcinosis in adult patients with dermatomyositis: a single cohort study.

OBJECTIVE: The occurrence of calcinosis cutis as a clinical feature of dermatomyositis in adult patients is not well understood. Cohort studies of adult patients with calcinosis are rare. We systematically describe the clinical features, treatments and outcomes of adult patients with calcinosis. METHODS: We initially enrolled 627 adult DM patients. Of those enrolled, 35 (5.6%) were found to have calcinosis. We analysed the clinical features associated with calcinosis in this subgroup. The risk factors associated with calcinosis were analysed using the Poisson regression model. RESULTS: Multivariate analysis showed that a younger age at disease onset [odds ratio (OR) = 0.945, 95% CI 0.925, 0.966, P < 0.001], dysphagia (OR = 2.609, 95% CI 1.189, 5.728, P = 0.017), skin ulcer (OR = 5.705, 95% CI 3.041, 10.705, P < 0.001) and the presence of anti-nuclear matrix protein 2 antibody (OR = 5.917, 95% CI 2.754, 12.714, P < 0.001) were independently associated with calcinosis. In both the low- and high-dose prednisone treatment groups, no difference in treatment response was seen between the bisphosphonate treatment group and the group not receiving bisphosphonate treatment (P = 1.000 and P = 0.375, respectively). A follow-up study revealed that the mortality rate of the calcinosis group was 5.7%. Additionally, 60.6% of the cases had a chronic polycyclic disease course and 17.1% had mild complications secondary to calcinosis. CONCLUSION: Calcinosis is an uncommon, but significant clinical feature in adult patients with DM. Bisphosphonates were not found to effectively treat calcinosis, however, the overall health outcomes of adult DM patients with calcinosis were favourable.

Interstitial lung disease is a major characteristic of anti-KS associated ant-synthetase syndrome.

BACKGROUND: Anti-KS autoantibodies are rare myositis-specific autoantibodies that have been described to target asparaginyl-transfer RNA synthetase. METHODS: Here, we review the published literature on critical issues concerning the detection of anti-KS antibodies and the clinical features associated with their presence. RESULTS: Seven articles are reviewed, in all of which immunoprecipitation was employed for the detection of anti-KS antibodies. A total of 47 patients were included; the ratio of females to males was 1.9:1. In total, 46 (98%) of these patients had interstitial lung disease (ILD), which was the sole manifestation in half (50%) of them. Pulmonary pathology revealed 7 (27%) with usual interstitial pneumonia, and 16 (62%) with non-specific pneumonia. Arthritis was present in about one-quarter (26%) of patients, and the incidence of Raynaud's phenomenon and mechanic's hands was 19% and 32%, respectively. However, manifestations of myositis were rare (9%). In addition, three (11%) patients had malignant tumors. Most patients responded to glucocorticoid therapy. CONCLUSIONS: Identifying anti-KS in patients with ILD may be useful for treatment, but reliable practical detection is needed. Furthermore, clinicians need to be aware of the possible presence of anti-KS antibodies in patients with ILD, either isolated or in combination with myositis.

Soluble IL-2 Receptor in Dermatomyositis: Its Associations with Skin Ulcers and Disease Activity.

OBJECTIVE: To investigate the role of soluble interleukin-2R (sIL-2R) in idiopathic inflammatory myopathies (IIM). METHODS: Serum sIL-2R levels were measured in 74 dermatomyositis (DM), 16 immune-mediated necrotizing myopathy (IMNM), 24 rheumatoid arthritis (RA), 20 systemic lupus erythematosus (SLE), and 20 healthy controls (HCs) by chemiluminescent immunometric assay. Clinical features and laboratory data were collected from electronic medical record. Disease activity was evaluated by using physician global disease activity and myositis disease activity assessment visual analog scale (MYOACT) on admission. 20 DM patients were followed. Serum sIL-2R levels were analyzed and compared with clinical features, laboratory data, and measures of disease activity. RESULTS: Serum sIL-2R levels were significantly higher in DM patients than in IMNM patients and HCs (648.8 ± 433.1 U/ml vs. 352.3 ± 126.0 U/ml and 648.8 ± 433.1 U/ml vs. 285.8 ± 101.9 U/ml, respectively; all P < 0.001), while there was no significant difference between IMNM and HCs. There were also no significant differences of sIL-2R levels in DM, SLE, and RA. Importantly, serum sIL-2R levels were significantly higher in treatment-naïve or active DM patients than those that are not (1100.9 ± 550.4 U/ml vs. 615.6 ± 330.4 U/ml, P = 0.006; 808.8 ± 421.6 U/ml vs. 339.8 ± 103.4 U/ml, P < 0.001). DM patients with skin ulcers had significantly higher sIL-2R levels than those without (889.3 ± 509.9 U/ml vs. 640.0 ± 368.7 U/ml, P = 0.023). Cross-sectional analysis in DM showed that sIL-2R levels positively correlated with CK, ESR, CRP, ferritin, physician VAS, and MYOACT scores (rho = 0.278, rho = 0.474, rho = 0.469, rho = 0.454, r = 0.646, and r = 0.600, respectively; all P < 0.05), negatively correlated with T cell counts and MMT8 scores (r = -0.380, P = 0.002; rho = -0.394, P = 0.001). Follow-up study showed that changes in sIL-2R levels after treatment correlated with changes in physician VAS and MYOACT scores (r = 0.823 and r = 0.695, respectively; all P < 0.01). CONCLUSION: Serum sIL-2R levels were elevated in DM but not in IMNM. Serum sIL-2R could act as a disease activity marker and be associated with ulcerative skin lesions in DM.

Clinical Features of Patients with Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders.

BACKGROUND: Neuromyelitis optica spectrum disorder (NMOSD) was long believed to be an aggressive form of multiple sclerosis (MS). This study aimed to describe the clinical features of patients with MS and NMOSD to assist in differential diagnoses in clinical practice. METHODS: Data including the patients' serum and cerebrospinal fluid (CSF) tests, image findings, and clinical information from 175 patients with MS or NMOSD at Xuanwu Hospital, Capital Medical University from November 2012 to May 2014 were collected and analyzed retrospectively. An enzyme-linked immunosorbent assay was performed to detect the myelin oligodendrocyte glycoprotein (MOG) autoantibodies in CSF and serum. Cell-based assays were used to detect aquaporin-4-antibody (AQP4-Ab). The Chi-square test was used to compare the categorical variables. Wilcoxon rank sum test was performed to analyze the continuous variables. RESULTS: Totally 85 MS patients (49%) and 90 NMOSD patients (51%) were enrolled, including 124 (71%) women and 51 (29%) men. Fewer MS patients (6%) had autoimmune diseases compared to NMOSD (19%) (Δ2 = 6.9, P < 0.01). Patients with NMOSD had higher Expanded Disability Status Scale scores (3.5 [3]) than MS group (2 [2]) (Z = -3.69, P < 0.01). The CSF levels of white cell count and protein in both two groups were slightly elevated than the normal range, without significant difference between each other. Positivity of serum AQP4-Ab in NMOSD patients was higher than that in MS patients (MS: 0, NMOSD: 67%; Δ2 = 63.9, P < 0.01). Oligoclonal bands in CSF among NMOSD patients were remarkably lower than that among MS (MS: 59%, NMOSD: 20%; Δ2 = 25.7, P < 0.01). No significant difference of MOG autoantibodies was found between the two groups. CONCLUSION: The different CSF features combined with clinical, magnetic resonance imaging, and serum characteristics between Chinese patients with MS and NMOSD could assist in the differential diagnosis.

Frequency selectivity in pulse responses of Pt/poly(3-hexylthiophene-2,5-diyl)/polyethylene oxide +Li+/Pt hetero-junction.

Pt/poly(3-hexylthiophene-2,5-diyl)/polyethylene oxide + Li+/Pt hetero junctions were fabricated, and their pulse responses were studied. The direct current characteristics were not symmetric in the sweeping range of ±2 V. Negative differential resistance appeared in the input range of 0 to 2 V because of de-doping (or reduction) in the side with the semiconductor layer. The device responded stably to a train of pulses with a fixed frequency. The inverse current after a pulse was related to the back-migrated ions. Importantly, the weight calculated based on the inverse current strength, was depressed during low-frequency stimulations but was potentiated during high-frequency stimulations when pulses were positive. Therefore, frequency selectivity was first observed in a semiconducting polymer/electrolyte hetero junction. Detailed analysis of the pulse response showed that the input frequency could modulate the timing of ion doping, de-doping, and re-doping at the semiconducting polymer/electrolyte interface, which then resulted in the frequency selectivity. Our study suggests that the simple redox process in semiconducting polymers can be modulated and used in signal handling or the simulation of bio-learning.