Polymyositis is a rare and favourable outcome subtype of idiopathic inflammatory myopathy in Chinese patients.

OBJECTIVES: To investigate the prevalence and characteristics of typical polymyositis (PM) in Chinese patients with idiopathic inflammatory myopathy (IIM). METHODS: Patients diagnosed with IIM according to the 2017 EULAR/ACR criteria were included. Serological aspects including myositis-specific antibodies (MSA) and pathological data were re-evaluated. The diagnosis of typical PM was strictly done using the pathological criteria, while excluding other IIM subtypes such as dermatomyositis (DM), immune-mediated necrotising myopathies (IMNM), anti-synthetase syndrome (ASS), and sporadic inclusion body myositis (sIBM), based on their respective diagnostic criteria. RESULTS: A total of 544 IIM patients with muscle biopsy were involved, and 129 of them were diagnosed with initial PM according to the 2017 EULAR/ACR criteria. Only 6 (1.1%, 6/544) patients met the strict definition of typical PM after re-evaluation. Patients with typical PM were MSA-negative (100% vs. 35.7%, p=0.003) and had CD8+ T cells surrounding or invading non-necrotic muscle fibres in muscle biopsies (100% vs. 7.8%, p<0.001) compared to the initially diagnosed PM patients. All typical PM patients achieved clinical remission at the second-year follow-up. Typical PM patients had a favourable prognosis compared to MSA-negative IMNM and unspecific myositis patients. CONCLUSIONS: Strictly defined typical PM is a rare clinical subtype in Chinese IIM patients. Typical PM patients with classical pathology were MSA-negative and responded well to treatment and had a favourable prognosis. It is crucial for clinicians to combine clinical, serological, and pathological features to properly distinguish PM from other IIM subtypes.

Spontaneous pneumomediastinum in anti-MDA5-positive dermatomyositis: Prevalence, risk factors, and prognosis.

OBJECTIVE: To depict the clinical panorama of spontaneous pneumomediastinum (SPM) in anti-MDA5 antibody-positive dermatomyositis (anti-MDA5+ DM). METHODS: A total of 1352 patients with idiopathic inflammatory myopathy (IIM), including 384 anti-MDA5+ DM patients were retrospectively enrolled. The clinical profiles of anti-MDA5+ DM-associated SPM were analyzed. RESULTS: We identified that 9.4 % (36/384) of anti-MDA5+ DM patients were complicated with SPM, which was significantly higher than that of non-anti-MDA5+ DM and other IIM subtypes (P all <0.001). SPM developed at a median of 5.5 (3.0, 12.0) months after anti-MDA5+ DM onset. Anti-MDA5+ DM patients complicated with SPM showed a significantly higher frequency of fever, dyspnea, and pulmonary infection including viral and fungal infections compared to those without SPM (P all < 0.05). Cytomegalovirus (CMV) and fungal infections were identified to be independent risk factors for SPM development in the anti-MDA5+ DM. SPM and non-SPM patients in our anti-MDA5+ DM cohort showed comparable short-term and long-term survival (P = 0.236). Furthermore, in the SPM group, we found that the non-survivors had a lower peripheral lymphocyte count, higher LDH level, and higher frequency of intensification of immunosuppressive treatment (IST) than survivors. The elevated LDH level and intensification of IST were independent risk factors for increased mortality in anti-MDA5+ DM-associated SPM patients. CONCLUSIONS: Nearly one-tenth of patients with anti-MDA5+ DM develop SPM. Both CMV and fungal infections are risk factors for SPM occurrence. The development of SPM does not worsen the prognosis of anti-MDA5+ DM patients, and the intensification of IST does harm to the SPM prognosis.

Upregulation of the CD155-CD226 Axis Is Associated With Muscle Inflammation and Disease Severity in Idiopathic Inflammatory Myopathies.

BACKGROUND AND OBJECTIVES: The CD155-CD226/T-cell Ig and immunoreceptor tyrosine-based inhibitory motif (ITIM) domain (TIGIT) pathway plays a critical role in regulating T-cell responses and is being targeted clinically. However, research on the role of this pathway in autoimmune diseases is limited. This study aimed to investigate the expression and tissue-specific roles of CD155-CD226/TIGIT pathway molecules in the inflamed muscles of patients with idiopathic inflammatory myopathies (IIMs). METHODS: Immunohistochemistry, Western blot analysis, and polychromatic immunofluorescence staining were performed to examine the expression of CD155, CD226, and TIGIT in skeletal muscle biopsies from 30 patients with dermatomyositis (DM), 10 patients with amyopathic DM (ADM), 20 patients with immune-mediated necrotizing myopathy (IMNM), 5 patients with dysferlinopathy, and 4 healthy controls. Flow cytometry analysis was used to analyze the functions of T cells with different phenotypes. RESULTS: Strong expression of CD155 was observed in patients with DM and IMNM, while its expression was largely negative in those with ADM and dysferlinopathy and healthy controls. The costimulatory receptor CD226 was highly expressed on muscle-infiltrating cells, while the coinhibitory receptor TIGIT was expressed at low levels. These infiltrating CD226+ cells were mainly activated effector T cells that localized adjacent to CD155-expressing myofibers, but were faintly detectable within the muscle fascicles lacking CD155. A strong positive correlation between CD155 and CD226 expression scores was also observed. Polychromatic immunofluorescence staining revealed that CD155+ muscle cells coexpressed major histocompatibility complex classes I and II, and tumor necrosis factor alpha expression was detected in CD226+ T cells at their close sites with the myofibers. Furthermore, the expression levels of CD155 and CD226 showed a positive correlation with creatine kinase, lactate dehydrogenase, and the muscle histopathology damage scores and an inverse correlation with the Manual Muscle Testing-8 scores. In addition, CD155 and CD226 expressions were significantly decreased in representative patients who achieved remission posttreatment. DISCUSSION: These findings demonstrate that the CD155-CD226 axis is highly activated in inflamed muscle tissues of patients with IIM and is associated with muscle disease severity. Our data uncover the immunopathogenic role of the axis in the pathology of IIMs.

Clinical characteristics of myositis patients with isolated anti-U1 ribonucleoprotein antibody resemble immune-mediated necrotizing myopathy.

Background: Anti-U1 ribonucleoprotein (U1RNP) antibodies were associated with connective tissue diseases (CTDs), but the clinical characteristics of this antibody in Chinese myositis patients have not been studied. Objective: We aim to analyze the clinical features of myositis patients who test positive for anti-U1RNP antibodies and delineate a subgroup of myositis. Design: This is a retrospective cohort study. Methods: We reviewed the clinical data of myositis patients with anti-U1RNP antibodies and compared them to those with anti-signal recognition particle (SRP) and hydroxy-3-methylglutaryl-CoA reductase (HMGCR) antibody-associated immune-mediated necrotizing myopathy (IMNM). Results: A total of 30 adult cases were identified; median age was 47.5 years and 24 (80%) were females, and 12 patients did not coexist with myositis-specific antibodies (MSAs) (isolated anti-U1RNP). The serum creatine kinase (CK) was significantly higher in patients with isolated anti-U1RNP (2182.5 U/L versus 289 U/L, p = 0.01), and the number of patients with CK > 2000 U/L was higher compared to that in anti-U1RNP antibody patients coexisting with MSAs (66.7% versus 16.7%, p = 0.009). The prevalence of IMNM in patients' muscle pathology with isolated anti-U1RNP was significantly higher (75%, p = 0.003). Skin rashes were less common in isolated anti-U1RNP group (p < 0.05). Of the 25 individuals with available pulmonary high-resolution CT (HRCT), 14 (56%) were diagnosed with interstitial lung disease (ILD). The incidence of muscular weakness, dysphagia, or levels of CK was not different between the isolated anti-U1RNP antibody individuals and the anti-HMGCR or SRP-IMNM groups (p > 0.05). But the frequency of Raynaud's phenomenon, arthritis, and membrane attack complex (MAC) deposits in myositis patients with isolated anti-U1RNP antibodies were higher than in anti-HMGCR and SRP-IMNM (all p < 0.005). There was no difference between anti-U1RNP patients with and without Ro-52 (p > 0.05). Isolated anti-U1RNP individuals showed marked improvements in muscle strength, and the remission rate in 1 and 2 years was significantly higher than that in anti-HMGCR and SRP-IMNM (p < 0.05). Conclusions: The clinical and pathological features of myositis patients with isolated anti-U1RNP antibodies were similar to IMNM. Arthritis and ILD are the most common extramuscular clinical features. Most respond well to treatment and have a good prognosis.

Predicting the Melting Point of Energetic Molecules Using a Learnable Graph Neural Fingerprint Model.

Melting point prediction for organic molecules has drawn widespread attention from both academic and industrial communities. In this work, a learnable graph neural fingerprint (GNF) was employed to develop a melting point prediction model using a dataset of over 90,000 organic molecules. The GNF model exhibited a significant advantage, with a mean absolute error (MAE) of 25.0 K, when compared to other featurization methods. Furthermore, by integrating prior knowledge through a customized descriptor set (i.e., CDS) into GNF, the accuracy of the resulting model, GNF_CDS, improved to 24.7 K, surpassing the performance of previously reported models for a wide range of structurally diverse organic compounds. Moreover, the generalizability of the GNF_CDS model was significantly improved with a decreased MAE of 17 K for an independent dataset containing melt-castable energetic molecules. This work clearly demonstrates that prior knowledge is still beneficial for modeling molecular properties despite the powerful learning capability of graph neural networks, especially in specific fields where chemical data are lacking.

Immunoproteasome subunit ß5i promotes perifascicular muscle atrophy in dermatomyositis by upregulating RIG-I.

BACKGROUND: Perifascicular atrophy is a unique pathological hallmark in dermatomyositis (DM)-affected muscles; however, the mechanism underlying this process remains unclear. In this study, we aimed to investigate the potential role of the immunoproteasome subunit ß5i and retinoic acid-inducible gene-I (RIG-I) in DM-associated muscle atrophy. METHODS: The expression of ß5i and RIG-I in the muscles of 16 patients with DM was examined by PCR, western blotting and immunohistochemistry. The associations between ß5i and RIG-I expression levels and muscle disease severity were evaluated. Lentivirus transduction was used to overexpress ß5i in human skeletal muscle myoblasts (HSMMs) and consequent cell functional changes were studied in vitro. RESULTS: ß5i and RIG-I expression in the muscle of patients with DM was significantly increased and closely associated with muscle disease severity. Immunohistochemistry and immunofluorescence analyses showed the marked colocalised expression of ß5i and RIG-I in perifascicular myofibres. ß5i overexpression in HSMMs significantly upregulated RIG-I, the muscle atrophy marker MuRF1, type I IFN-related proteins (MxA and IFNß) and NF-κB pathway-related proteins (pIκBα, pIRF3 and pNF-κBp65). In addition, the viability of HSMMs decreased significantly after ß5i overexpression and was partly recovered by treatment with a ß5i inhibitor (PR957). Moreover, activation of RIG-I by pppRNA upregulated IFNß and MuRF1 and reduced the cell viability of HSMMs. CONCLUSION: The immunoproteasome subunit ß5i promotes perifascicular muscle atrophy in DM via RIG-I upregulation; our findings suggest a pathomechanistic role of ß5i and RIG-I in DM-associated muscle damage, highlighting these components as potential therapeutic targets for the treatment of DM.

Peripheral lymphocyte count defines the clinical phenotypes and prognosis in patients with anti-MDA5-positive dermatomyositis.

OBJECTIVE: To explore the role of peripheral lymphocyte count in phenotyping and prognosis prediction in dermatomyositis (DM) patients with anti-MDA5 antibodies. METHODS: In total, 1669 patients with idiopathic inflammatory myopathy (IIM) were retrospectively enrolled. Clinical characteristics and prognosis of patients with anti-MDA5+ DM were analyzed in association with peripheral lymphocyte counts and clusters determined by unsupervised machine learning. RESULTS: The peripheral lymphocyte count was significantly lower in the anti-MDA5+ DM group (N = 421) than in the other IIM serotype groups. The anti-MDA5+ DM patients were divided into three groups; the severe lymphopenia group had skin ulcers and rapidly progressive interstitial lung disease (RP-ILD); patients with a normal lymphocyte count had a younger age of onset, more frequent arthritis, and normal serum ferritin levels, whereas mild lymphopenia group showed a moderate increase of serum ferritin and intermediate incidence of RP-ILD. Survival analysis revealed that the 3- and 6-month mortality rates were significantly higher in the severe lymphopenia group (29.0% and 42.1%, respectively) than in the mild lymphopenia group and normal lymphocyte count group (p value <0.001). Consistently, unsupervised machine learning identified three similar groups; the arthritis cluster shows the highest lymphocyte counts and best prognosis; the RP-ILD cluster presents the lowest peripheral lymphocyte, high incidence of RP-ILD, and poor prognosis; the typical DM rash cluster had a moderate peripheral lymphocyte count and an intermediate prognosis. CONCLUSIONS: Lymphopenia is a unique manifestation of anti-MDA5+ DM. Peripheral lymphocyte count can define clinical phenotypes and predict prognosis in anti-MDA5+ DM.

Long-Term Outcomes and Prognosis Factors in Patients With Idiopathic Inflammatory Myopathies Based on Myositis-Specific Autoantibodies: A Single Cohort Study.

OBJECTIVE: This study was undertaken to investigate the long-term survival rates and prognostic factors in patients with idiopathic inflammatory myopathies (IIMs) based on myositis-specific antibody (MSA) stratification. METHODS: Exactly 628 patients with an IIM were included. Kaplan-Meier survival curves, univariate, and multivariate Cox regression were used to analyze the outcomes and risk factors. RESULTS: The cumulative 1-, 5-, and 10-year survival rates for IIM patients overall were 91.4%, 82.8%, and 75.6%, respectively. The survival rate in the MSA subset was significantly different (P < 0.001). The 1- and 10-year survival rates in the anti-melanoma differentiation-associated protein 5 (anti-MDA-5)-positive subgroup were 79.5% and 58.5%, respectively, which were the lowest among all subgroups. The 10-year survival rate of anti-signal recognition particle (anti-SRP)-positive patients was the highest (96.4%). Independent risk factors that impacted the long-term prognosis for IIM patients included rapidly progressive interstitial lung disease (RP-ILD), malignancy, and elevated serum ferritin levels (hazard ratio [HR] 17.47, 20.36, and 9.15, respectively, P < 0.01), whereas disease duration was a protective factor (HR 0.27, P = 0.003). Among these subsets, the strongest independent risk factor for death in the anti-MDA-5-positive subgroup was RP-ILD (HR 3.4, P = 0.017). Malignancy was an independent risk factor in the anti-aminoacyl-tRNA synthetase antibody-positive, anti-transcription intermediary factor 1γ-positive, and MSA-negative subgroups (HR 46.69, 6.65, and 4.48, respectively; P < 0.001). RP-ILD was also a risk factor in the prognosis of individuals in the MSA-negative subgroup (HR 72.28, P < 0.001). CONCLUSION: Despite favorable overall survival in patients with IIM, the anti-MDA-5-positive subgroup had the highest mortality rate among all MSA subgroups, highlighting the distinctive prognosis for patients with different MSAs. RP-ILD and malignancy are the most common causes of death in IIM patients.

Clinical and pathological features of immune-mediated necrotising myopathies in a single-centre muscle biopsy cohort.

OBJECTIVE: Immune-mediated necrotising myopathy (IMNM) is a subset of idiopathic inflammatory myopathies (IIM) characterized by significantly elevated creatine kinase level, muscle weakness and predominant muscle fibre necrosis in muscle biopsy. This study aimed to investigate the clinical and pathological characteristics of patients with IMNM in a single-centre muscle biopsy cohort. METHODS: A total of 860 patients who had muscle biopsy reports in our centre from May 2008 to December 2017 were enrolled in this study. IMNM was diagnosed according to the 2018 European Neuromuscular Centre (ENMC) clinicopathological diagnostic criteria for IMNM. RESULTS: The muscle biopsy cohort consisted of 531 patients with IIM (61.7%), 253 patients with non-IIM (29.4%), and 76 undiagnosed patients (8.8%). IIM cases were classified as IMNM (68[7.9%]), dermatomyositis (346[40.2%]), anti-synthetase syndrome (82[9.5%]), polymyositis (32[3.7%]), and sporadic inclusion body myositis (3[0.3%]). Limb girdle muscular dystrophy (LGMD) 2B and lipid storage myopathy (LSM) are the two most common non-IIM disorders in our muscle biopsy cohort. IMNM patients had a higher onset age (41.57 ± 14.45 vs 21.66 ± 7.86 and 24.56 ± 10.78, p < .0001), shorter duration (21.79 ± 26.01 vs 66.69 ± 67.67 and 24.56 ± 10.78, p < .0001), and more frequent dysphagia (35.3% vs. 3.4 and 6.3%, p = .001) than LGMD 2B and LSM patients. Muscle biopsy from IMNM showed more frequent muscle fibre necrosis (95.6% vs 72.4 and 56.3%, p < .0001), overexpression of major histocompatibility complex-I on sarcolemma (83.8% vs 37.9 and 12.9%, p < .0001), and CD4+ T cell endomysia infiltration (89.7% vs 53.6 and 50%, p < .0001) compared with those from LGMD 2B and LSM patients. CONCLUSIONS: It is easy to distinguish IMNM from other IIM subtypes according to clinical symptoms and myositis specific antibodies profiles. However, distinguishing IMNM from disorders clinically similar to non-IIM needs combined clinical, serological and pathological features.

Serum levels of anti-transcriptional intermediary factor 1-γ autoantibody associated with the clinical, pathological characteristics and outcomes of patients with dermatomyositis.

OBJECTIVE: To investigate the association of the serum levels of anti-transcriptional intermediary factor 1 (TIF1)-γ autoantibodies with the clinical and pathological characteristics, as well as the prognosis of adult patients with dermatomyositis (DM). METHODS: Eighty-seven adult DM patients with anti-TIF1-γ autoantibodies positive screened by immunoblotting assay were enrolled in the study. The presence and levels of anti-TIF1-γ autoantibodies were examined through enzyme-linked immunosorbent assay (ELISA). Muscle biopsy specimens were obtained from 52 patients, and immunohistochemistry was performed to visualize major histocompatibility complex (MHC)-I, CD3, CD20 and C5b-9. Muscle biopsy scores and disease activity were evaluated. RESULTS: A total of 80 patients were positive for anti-TIF1-γ autoantibodies confirmed by ELISA assay, including 30 cancer-associated myositis (CAM) and 50 non-CAM. Serum levels of anti-TIF1-γ autoantibodies did not significantly differ between the CAM and non-CAM groups. The levels of anti-TIF1-γ were associated with disease activity scores. A total of 63.9% of non-CAM patients displayed a classical DM pathological phenotype. Conversely, CAM patients presented with classical DM (25%), immune-mediated necrotizing myopathy (25%), non-specific myositis (32.3%), and normal (18%) phenotypes of muscle biopsy. Anti-TIF1-γ autoantibody levels were positively associated with muscle biopsy total scores, muscle fiber scores and inflammatory infiltration scores in the non-CAM patients but not in the CAM patients. The survival rate of CAM patients presenting with high anti-TIF1-γ autoantibody levels was lower than that of patients with low levels. However, no difference in survival rate was observed in the non-CAM group between high and low autoantibody levels. CONCLUSION: The distinct associations of anti-TIF1-γ autoantibody levels with disease activity, muscle histopathology damage and outcome indicated that different pathogenesis might be involved in DM with or without cancer.

Contribution of Necroptosis to Myofiber Death in Idiopathic Inflammatory Myopathies.

OBJECTIVE: Myofiber necrosis is a significant pathologic characteristic of idiopathic inflammatory myopathies (IIMs), and its molecular mechanism is largely unknown. Necroptosis is a recently identified form of regulated necrotic cell death, and its activation might have crucial biologic consequences. The aim of the present study was to investigate the role of necroptosis in IIM muscle damage. METHODS: Western blot and immunohistochemistry analyses were performed to examine the expression of receptor-interacting protein 3 (RIP-3) and mixed-lineage kinase domain-like (MLKL) proteins in 26 IIM patients and 4 healthy controls, as well as necroptosis-related damage-associated molecular pattern molecules. Tumor necrosis factor (TNF) was used to stimulate cultured C2C12 myoblasts, and the involvement of necroptosis in cell death of C2C12 cells was studied in vitro. RESULTS: The expression of RIP-3 and MLKL proteins and their phosphorylated forms was significantly increased in the muscle tissue of IIM patients compared to that of healthy controls. The expression levels of RIP-3 and MLKL proteins were associated with the severity of muscle damage in patients with IIM. Significant colocalization of MLKL with high mobility group box chromosomal protein 1 in necrotizing myofibers was observed in muscle biopsy tissue from patients with IIM. Stimulation of C2C12 myoblasts with TNF and a pan-caspase inhibitor, Z-VAD, resulted in the overactivation of necroptosis and significantly increased necrotic cell death. Strategies involving either inhibition of necroptosis with necrostatin-1 or knockdown of MLKL expression successfully prevented necroptosis-induced cell death of C2C12 cells. CONCLUSION: These findings demonstrate that overactivated necroptosis contributes to muscle damage in IIMs and suggest that necroptosis inhibitors could represent a new therapeutic target in the treatment of IIMs.

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis responds to rituximab therapy.

OBJECTIVES: The purpose of this study was to assess the efficacy of rituximab (RTX) in the management of anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis (DM), with or without rapidly progressive interstitial lung disease (RP-ILD). METHODS: Medical records of DM patients with anti-MDA5 antibodies treated with RTX therapy were reviewed retrospectively. Skin rash data, lung function tests, chest high-resolution computed tomography (HRCT), and serum markers were compared before and after RTX. RESULTS: Eleven consecutive cases, including 5 males and 6 females, were identified. One hundred percent of patients had a typical DM rash and about 45% presented with skin ulceration. All the patients had ILD, 73% had RP-ILD, and 27% had mild or asymptomatic ILD. Ro-52 antibodies were found in 55% of this group. Lymphopenia was present in 10/11 patients (91%). Around half (55%) had a level of ferritin greater than 1000 ng/ml. Nine patients (82%) were refractory. These patients received intravenous RTX (375 mg/m2) at 0 and 14 days (conventional dose) or 100 mg once a week for 4 weeks (low dose). After RTX treatment, 2 patients (18%) with mild ILD showed complete remission, and 6 (55%) showed improvement in lung HRCT and/or lung function. Skin rash in 4 patients (100%) and ILD in 3 (75%) showed improvement in the low-dose group. Infection episodes occurred in four (57%) and one (25%) of the conventional-dose and low-dose group, respectively. CONCLUSIONS: Our study found that RTX is sufficient to improve skin rash and ILD or RP-ILD. Our results also suggest that lower RTX doses may be a useful therapy for anti-MDA5 antibody-positive DM patients. Key Points • To clarify efficacy of RTX in the management of anti-MDA5 antibody-positive DM, we performed a retrospective chart review of DM patients with anti-MDA5 antibodies who were treated with RTX. • This study found that RTX is sufficient to improve skin rash and ILD or RP-ILD. • The results suggest that low-dose RTX in treatment of MDA5-DM results in better responses and fewer adverse events.

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.

Clinical features and outcomes of the patients with anti-glycyl tRNA synthetase syndrome.

OBJECTIVE: To analyze the clinical features and outcomes of the patients with anti-glycyl tRNA synthetase (anti-EJ) syndrome in a large Chinese cohort. METHODS: The medical records, imaging, and serologic data of patients with anti-EJ antibodies from the China-Japan Friendship Hospital database were retrospectively investigated. Anti-EJ antibodies were identified using immunoblot assay. Long-term follow-up was conducted. RESULTS: Anti-EJ antibodies were present in 46 (19.7%) of the 234 patients with antisynthetase syndrome (ASS), preceded by anti-Jo-1 and anti-PL-7 antibodies. The mean age of disease onset was 51.2 ± 15.9 years, and 69.6% of these patients were female. The most prevalent clinical feature was interstitial lung disease (ILD) (96.7%), which was also the most common initial manifestation, followed by fever (60.9%), mechanic's hands (56.5%), muscle involvement (50%), and Raynaud phenomenon (8.7%). Ten (21.7%) patients developed rapidly progressive ILD (RP-ILD). Organizing pneumonia (OP) on high-resolution computed tomography (HRCT) scans (OR = 37.5, p = 0.006) and a higher C-reactive protein-to-albumin ratio (CAR) (OR = 28.3, p = 0.01) were independent risk factors for RP-ILD. Muscular pathological features were heterogeneous. Concomitant infection was noted in 63.0% of the patients during the disease course. Hypoalbuminemia (OR = 0.759, p = 0.002) was an independent risk factor for concomitant infection. Patients responded well to glucocorticoid therapy. The 5- and 10-year survival rates of the patients with anti-EJ were 97.8% and 88%, respectively. CONCLUSION: Anti-EJ syndrome was found to be a relatively common ASS subtype, with a favorable outcome. A notable proportion of the patients experienced RP-ILD, which was prone to OP on HRCT and a higher CAR, and needed aggressive management. Key Points • ILD was the most common initial manifestation of anti-glycyl tRNA synthetase syndrome. • RP-ILD was notable in anti-EJ positive patients. • Anti-EJ positive patients possessed a favorable long-term prognosis, but easily relapsed.

Application of loop-mediated isothermal amplification (LAMP) for rapid detection of Atlantic cod (Gadus morhua), Pacific cod (Gadus macrocephalus) and haddock (Melanogrammus aeglefinus).

Codfish is a commercially important species of sea fish and plays an important role in the world fishery. In our study, two loop-mediated isothermal amplification (LAMP) assays (real-time fluorescence LAMP and visual LAMP) were established for the identification of three cod species in Gadidae (Gadus morhua, Gadus macrocephalus and Melanogrammus aeglefinus). 12S rDNA gene was used to design primers to distinguish the Gadidae and non-Gadidae species, and the mitochondrial Cytb gene was selected for discrimination of three cod species. After optimization, the 12S rDNA system and species-specific systems performed well, and target cod DNA could be detected in single or mixed samples. In the species-specific systems, the absolute limit of detection (LODa) of three cod species were 285, 37 and 197 pg/µL, and the relative limit of detection (LODr) reached to 1%, 0.1% and 1%, respectively. In the 12S rDNA system, the LODa of three cod species were 28.5, 37 and 19.7 pg/µL, respectively, and the LODr reached to 0.1%. Through the detection of 13 commercial cod products, the LAMP systems can detect cod contents in raw materials and deep-processed products as well. It indicated that the methods developed in this study have strong practicability and can meet the needs of routine testing.

Pretreatment with NaCl Promotes the Seed Germination of White Clover by Affecting Endogenous Phytohormones, Metabolic Regulation, and Dehydrin-Encoded Genes Expression under Water Stress.

This study was designed to examine the effects of NaCl pretreatment on the seed germination of white clover (Trifolium repens cv. Ladino) under water stress induced by 19% polyethylene glycol (PEG) 6000. Lower concentrations of NaCl (0.5, 1, and 2.5 mM) pretreatment significantly alleviated stress-induced decreases in germination percentage, germination vigor, germination index, and radicle length of seedlings after seven days of germination under water stress. The soaking with 1 mM of NaCl exhibited most the pronounced effects on improving seed germination and alleviating stress damage. NaCl-induced seeds germination and growth could be associated with the increases in endogenous gibberellic acid (GA) and indole-3-acetic acid (IAA) levels through activating amylases leading to improved amylolysis under water stress. Seedlings pretreated with NaCl had a significantly lower osmotic potential than untreated seedlings during seed germination, which could be related to significantly higher soluble sugars and free proline content in NaCl-treated seedlings under water stress. For antioxidant metabolism, NaCl pretreatment mainly improved superoxide dismutase, peroxidase, ascorbate peroxidase, and glutathione reductase activities, transcript levels of FeSOD, APX, and DHAR, and the content of ascorbic acid, reduced glutathione, and oxidized glutathione during seed germination under water stress. The results indicated that seeds soaking with NaCl could remarkably enhance antioxidant metabolism, thereby decreasing the accumulation of reactive oxygen species and membrane lipid peroxidation during germination under water stress. In addition, NaCl-upregulated dehydrin-encoded genes SK2 expression could be another important mechanism of drought tolerance during seeds germination of white clover in response to water stress.

Direct loop-mediated isothermal amplification assay for on-site detection of Staphylococcus aureus.

Staphylococcus aureus (S. aureus) is a major human pathogen that may produce a variety of toxins and cause staphylococcal food poisoning. In the present study, a direct loop-mediated isothermal amplification (LAMP) assay was developed and validated to detect S. aureus in food samples. Without prior cultural enrichment and DNA extraction steps, bacterial DNA was released by heating at 100°C for 5 min and directly subjected to LAMP assay. Using a set of LAMP primers recognizing six distinct regions of nuc gene, the developed direct LAMP assay was highly specific, and the analytical sensitivity was determined to be 7.6 × 102 CFU/mL. Moreover, with the pre-mixed LAMP reagents stored at -20°C, the entire assay should be finished within 40 min. These features greatly simplified the operating procedure and made the direct LAMP a powerful tool for rapid and on-site detection of S. aureus in food samples.

Potential role of autophagy in T­cell survival in polymyositis and dermatomyositis.

Peripheral blood T lymphocytopenia has previously been identified in polymyositis/dermatomyositis (PM/DM) patients. Therefore, the present study aimed to examine the potential role of autophagy in peripheral blood T cell survival in PM/DM patients. Transmission electron microscopy was used to detect the formation of autophagosomes of peripheral blood cluster of differentiation (CD)3+ T cells obtained from 24 patients with PM/DM and 21 healthy controls. Protein and mRNA expression levels of autophagy­related molecules were examined by western blot analysis and reverse transcription­quantitative polymerase chain reaction, respectively. The number of peripheral blood CD3+ T cells decreased significantly in PM/DM patients. The median percentage of apoptosis of CD3+ T cells in PM/DM patients was significantly increased compared with healthy controls. Furthermore, the number of autophagosomes and the expression of the autophagy markers microtubule­associated protein 1A/1B­light chain 3 (LC3) and Beclin­1 were significantly reduced in the circulating CD3+ T cells of PM/DM patients compared with those of healthy controls. LC3 and Beclin­1 protein levels correlated negatively with apoptosis rates in circulating CD3+ T cells in patients with PM/DM. CD3+ T cells from PM/DM patients treated with rapamycin increased autophagy and decreased apoptosis compared with untreated cells (P<0.05). In conclusion, these results suggested that autophagy may serve a potential protective role in the peripheral blood T cells of patients with PM/DM.

Significant decrease in peripheral regulatory B cells is an immunopathogenic feature of dermatomyositis.

Regulatory B cells (Bregs) are critical in maintaining self-tolerance. Their role in dermatomyositis (DM), an autoimmune disease characterized by inappropriate regulation of hyperactivated B and T cells, has not been clearly defined. In the current study, we performed flow cytometry analysis of studied CD19(+) CD24(high)CD38(high) Breg subpopulations in blood samples from 30 patients with DM, 37 diseased controls and 23 healthy controls. A significant decrease was observed in the frequency of Bregs in DM patients compared to that in diseased controls (p < 0.0001) and in healthy controls (p < 0.0001). And the prevalence of Bregs deficiency (defined as Bregs/B cells < 0.50% in this study) in DM patients went as high as 73.3%. Furthermore, DM patients with positive myositis specific autoantibody often had lower Bregs levels than negative patients (p = 0.036), and lower level of Bregs was also found in DM patients with interstitial lung disease than in DM patients without (p = 0.041). In a follow-up study, seven DM patients were considered to be in remission stage, and their Breg levels were found to have significantly increased after treatment (p = 0.022). Our research revealed that Breg deficiency is an immunopathogenic feature of DM and provided insights into the design of new immunotherapy target for DM clinical interventions.