Myositis Research Articles

Impact of SARS-CoV-2 on the clinical presentation of juvenile idiopathic inflammatory myopathies

BackgroundGrowing evidence suggests that infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may trigger idiopathic inflammatory myopathies (IIM). Few studies have described individual juvenile IIM (JIIM) cases following SARS-CoV-2 infection, and none explored its potential effects on JIIM clinical presentation. We aim to investigate the impact of SARS-CoV-2 on JIIM in patients diagnosed before and after the onset of the Coronavirus Disease 2019 (COVID-19) pandemic.MethodsPatients diagnosed with JIIM before age 19 at The Children’s Hospital at Montefiore were included. Demographics, clinical and laboratory data, and evidence of SARS-CoV-2 exposure were collected retrospectively. Patients were grouped by pre-COVID-19 (before January 1, 2020) and post-COVID-19 (January 1, 2020, or later). Descriptive statistics were used to summarize each variable. Non-parametric testing was performed using Fischer’s exact test and Mann-Whitney U test.ResultsFifty-one patients were included, 13 (25%) diagnosed in the post-COVID-19 era. Of these, 10 (77%) had onset of JIIM symptoms after January 1, 2020; 6 (60%) with known or suspected SARS-CoV-2 exposure. Though not statistically significant, post-pandemic patients tended to be older, female, and have non-specific cutaneous manifestations. Despite reported delays in care for other pediatric diagnoses during the pandemic, fewer post-pandemic patients had delays in JIIM diagnosis.ConclusionsThis is the first study to explore the effects of SARS-CoV-2 on JIIM clinical presentation. While our exploratory single-center study did not find significant differences in JIIM diagnosed pre- and post-pandemic, larger prospective multicenter studies are warranted to evaluate this association and to explore clinical variances over time.

Deciphering the crosstalk of immune dysregulation between COVID-19 and idiopathic inflammatory myopathy.

The coronavirus disease (COVID-19) pandemic is a serious threat to public health worldwide. Growing evidence reveals that there are certain links between COVID-19 and autoimmune diseases; in particular, COVID-19 and idiopathic inflammatory myopathies (IIM) have been observed to be clinically comorbid. Hence, this study aimed to elucidate the molecular mechanisms of COVID-19 and IIM from a genomic perspective. We obtained transcriptome data of patients with COVID-19 and IIM separately from the GEO database and identified common differentially expressed genes (DEGs) by intersection. We then performed functional enrichment, PPI, machine learning, gene expression regulatory network, and immune infiltration analyses of co-expressed genes. A total of 91 common genes were identified between COVID-19 and IIM. Functional enrichment analysis revealed that these genes were mainly involved in immune dysregulation, response to external stimuli, and MAPK signaling pathways. The MCODE algorithm recognized two densely linked clusters in the common genes, which were related to inflammatory factors and interferon signaling. Subsequently, three key genes (CDKN1A, IFI27, and STAB1) were screened using machine learning to predict the occurrence of COVID-19 related IIM. These key genes exhibited excellent diagnostic performance in both training and validation cohorts. Moreover, we created TF-gene and miRNA-gene networks to reveal the regulation of key genes. Finally, we estimated the relationship between key genes and immune cell infiltration, of which IFI27 was positively associated with M1 macrophages. Our work revealed common molecular mechanisms, core genes, potential targets, and therapeutic approaches for COVID-19 and IIM from a genomic perspective. This provides new ideas for the diagnosis and treatment of COVID-19 related IIM in the future.

E58 The rheumatologic masquerader: a case report on SLE-dermatomyositis-systemic scleroderma overlap syndrome

Abstract Introduction Juvenile dermatomyositis is an autoimmune connective tissue disorder characterized by idiopathic inflammatory myopathy primarily affecting the skin and muscles(1, 2). It may occur alone or in overlap syndromes usually with systemic scleroderma, systemic lupus erythematosus (SLE) and mixed connective tissue disease(3, 4). There is need to further describe and characterize cases encountered in different set ups. Objective To describe a case of dermatomyositis-scleroderma overlap in an African male adolescent. Methods We carried out a retrospective chart review to ascertain clinical features and management strategies. Results We present a case of a 17- year old African male patient who presented with a diagnosis of systemic lupus erythematosus made at a peripheral facility in February 2021, and started on azathioprine 50 mg daily, hydroxychloroquine 200 mg daily and prednisolone 5 mg twice daily. He presented on 30th November 2022 with a 2-year history of bilateral elbow, knee, ankle pain and swelling with an 8-month history of bilateral proximal upper and lower limb muscle weakness. Review of systems revealed alopecia, occasional fever and hyperpigmentation over his proximal interphalangeal and metacarpophalangeal joints that has since evolved to hypopigmentation. Positive examination findings included fine sparse hair, heliotrope rash, Gottron's papule, salt and pepper skin rash, hardening of the skin over the arm and thighs with a rodnan score 3/3 over the phalanges, nodular non tender lesions in the abdominal subcutaneous tissue and dactylitis with fixed flexion deformities of both elbows. He had bilateral flexion contractures of both elbows and knees with dactylitic fingers. Laboratory investigations showed an elevated CRP 94 mg/l, elevated lactate dehydrogenase 458 U/l, elevated creatine kinase 492U/l, positive antinuclear antibodies (1:640 titres) with a nuclear coarse and large speckled pattern, positive double stranded DNA antibodies and weak positive anti SM, anti RNP and PCNA antibodies. Myositis panel was positive for MDA5 and OJ. Pelvic MRI showed features of proximal inflammatory myositis. The childhood myositis assessment scale revealed a score of 25/52. ECHO and chest radiograph were normal. Pulmonary function test showed a low FEV 1 and FVC in keeping with a restrictive lung picture. Gastroenterology review revealed gastritis with no other stigmata of autoimmune disease. Management has consisted of monthly therapy with intravenous immunoglobulin. Azathioprine therapy was switched with mycophenolate mofetil 1 gram twelve hourly. He was advised on sunscreen protection. Physiotherapy and occupational therapy has been ongoing. Three months of follow up has led to the resolution of the flexion knee contractures, improved functionality in activities of daily living and a rodnan score of 2/3 over the phalanges. Conclusion SLE-juvenile dermatomyositis and systemic scleroderma can occur as an overlap syndrome and a definitive diagnosis remains elusive to many clinicians. A thorough history and comprehensive physical examination remains key to establishing a correct diagnosis. Early patient referral to paediatric rheumatologist for prompt appropriate treatment can avert debilitating morbidity and mortality.

E53 Anti-OJ synthetase syndrome: a pediatric case report

Abstract Introduction The antisynthetase syndrome (ASS) is a connectivity with variable clinical expression. It is defined by the presence of anti-tRNA synthetase autoantibodies, associated with a clinical phenotype. It is an overlapping myositis associated with the presence of idiopathic inflammatory myopathy autoantibodies. Observation We report the case of an 11-year-old girl with no particular family history. The patient was diagnosed and treated as rheumatic fever 3 years ago and put on extencillin due to arthralgias of large right knee and hip joints with positive antistreptolysin O antibodies and history of repeated angina but without clinical improvement. The polyarthralgias progressed and became bilateral predominantly in the scapular and pelvic girdles associated with intense myalgias of three days before his admission leading to a motor deficit. A biological assessment was requested: creatine phosphokinase (CPK) = 1880UI/l; ASAT = 58UI/l; procalcitonin = 0.15; erythrocytesedimentation rate (ESR) was elevated. The immunological workup showed antibodies specific for myositis; antiRNA synthetase type OJ Positive. Results of immunological tests for other associated autoimmune diseases were (rheumatoid factor, anti-CyclicCitrullinated Peptide antibodies, anti SM and anti-Native DNA) negative. Electromyography showed no abnormalities. A muscle biopsy was not done. Chest CT scan showed no abnormalities. The patient was commenced on corticosteroid therapy at a dose of 1 mg/kg/day for 4–6 weeks then progressive weaning. Conclusion ASS is a complex and heterogeneous autoimmune connective disease. In the presence of extra-pulmonary signs and the positivity of the anti-tRNA synthetase antibody, the diagnosis is confirmed. The management often requires multidisciplinary approach.

Value of the HFA-PEFF diagnostic algorithms for heart failure with preserved ejection fraction to the inflammatory myopathy population

ObjectivesThe HFA-PEFF score has been validated to hold great diagnostic and prognostic utility for heart failure with preserved ejection fraction (HFpEF). Idiopathic inflammatory myopathy (IIM) is recognized as one of the potential etiologies underlying HFpEF. Here, we intended to investigate the real prevalence of HFpEF in IIM via the HFA-PEFF score and explore the prognostic value of this score.MethodsTwo hundred twenty IIM patients were enrolled for assessment. The cohort was divided into low, intermediate and high tertiles of the HFA-PEFF score. Spearman’s correlation analysis was used to explore the association between the score and disease activity. Chi-square test was applied to investigate the distribution discrepancy of HFA-PEFF tertiles among patients with different myositis-specific antibodies (MSAs) or myositis-associated antibodies (MAAs). Univariate and multivariate ordinal regression analyses were performed to screen risk factors for high HFA-PEFF scores. Survival curves were obtained using the Kaplan–Meier method and log-rank tests.ResultsIn total, 79 (35.9%), 107 (48.6%) and 34 (15.5%) patients were rated low, intermediate and high probability of HFpEF, respectively. The HFA-PEFF score correlated well with disease activity. Patients with positive AMA-M2 scored higher in the HFA-PEFF score (p = 0.011). During follow-up, patients with positive AMA-M2 or anti-SRP antibody developed an inclination towards concentric hypertrophy on echocardiography. Additionally, palpitation symptom, AMA-M2 positivity and elevated serum levels of LDH, cTnI were independent risk factors for high HFA-PEFF scores. Finally, a high-tertile HFA-PEFF score was related to lower overall survival rate (p < 0.001). Patients with positive AMA-M2 had poorer outcomes (p = 0.002).ConclusionHFpEF was prevailing in IIM patients according to the HFA-PEFF score. The HFA-PEFF score correlated well with disease activity and held significant prognostic value. Patients with AMA-M2 antibody were prone to have poor outcomes.

Interstitial lung disease with and without progressive fibrosing phenotype in patients with idiopathic inflammatory myopathies: data from a large multicentric cohort

ObjectivesPatients with connective tissue diseases can develop interstitial lung disease (ILD), leading to a progressive fibrosing ILD (PF-ILD) phenotype in some cases. We aimed to investigate the occurrence of PF-ILD...

Cancer and idiopathic inflammatory myopathies –association of autoantibodies with carcinogenesis

The relationship between cancer development in the course of idiopathic inflammatorymyopathies (IIM) has already been noticed at the beginning of the 20th century. However, theunderlying mechanisms remain not fully understood. Risk factors for carcinogenesis in patientswith IIM include male sex, older age, and the presence of specific subtypes of inflammatorymyopathies and clinical manifestations, including dermatomyositis, dysphagia, severe skinchanges, leukocytoclastic vasculitis, acute disease onset and immunosuppressive therapyresistance. The presence of certain autoantibodies in the serum of patients with IIM is a factorof considerable importance in the stratification of cancer risk. Anti-TIF1γ autoantibodies, which might be present in even 38-80% of cancer cases in adult IIM patients, are antibodies with a wellstudiedrelationship with carcinogenesis. The relationship of other antibodies found in IIM withthe risk of carcinogenesis is still discussed. This group includes anti-NXP2, anti-HMGCR, anti-SAE1 and anti-Mi2 antibodies. Due to the contrary reports on the role of these antibodies incancer development and their relatively low prevalence in IIM, the unambiguous classificationas risk factors requires further research in larger study groups. The potential autoantibodiesutility in cancer screening in IIM patients could help detect cancer early, improving prognosisand long-term survival.

Cancer Screening for Dermatomyositis: A Survey of Indirect Costs, Burden, and Patient Willingness to Pay.

Dermatomyositis (DM) is a rare idiopathic inflammatory myopathy (IIM) associated with an increased risk for malignancy. Although cancer screening is recommended, no consensus guidelines currently exist. Whole-body positron emission tomography/ computed tomography (PET/CT) has similar cost and efficacy to a more traditional conventional cancer screening panel (CSP). Our study sought to characterize patients' perspective of cancer screening and the indirect costs to patients. We conducted a survey of patients recently diagnosed with DM who were undergoing or had recently undergone a CSP. Patient values and indirect costs need to be considered in choosing a screening modality. This study contributes to a greater understanding of patients' experience of cancer screening in DM, which should be taken into consideration when developing consensus guidelines for cancer screening.

Single-cell profiling of muscle-infiltrating T cells in idiopathic inflammatory myopathies.

Idiopathic inflammatory myopathies (IIM) are rare autoimmune systemic diseases characterized by muscle weakness and the presence of muscle-infiltrating T cells. IIM represent a clinical challenge due to heterogeneity of symptoms and variability of response to immunosuppressive treatment. Here, we performed in-depth single-cell sequencing on muscle-infiltrating T cells and peripheral blood memory T cells in six patients with recently diagnosed IIM. We identified tissue resident memory T-cell (TRM ) signatures including the expression of HOBIT, XCL1 and CXCR6 in the muscle biopsies of all patients with IIM. Clonally expanded T-cell clones were mainly found among cytotoxic and TRM implying their role in the disease pathogenesis. Finally, identical expanded T-cell clones persisting at follow-up in the muscle tissue of two patients suggest their involvement in disease chronicity. Our study reveals a muscle tissue resident memory T-cell signature in patients with IIM and a transcriptomic map to identify novel therapeutic targets in IIM.

High‐throughput transcriptomic profiling of mRNAs and lncRNAs in the dermatomyositis muscle by RNA sequencing

AbstractBackgroundDermatomyositis (DM) is an idiopathic inflammatory myopathy (IIM). In this study, we investigated the mRNAs and long noncoding RNAs (lncRNAs) in muscle biopsy specimens that are differentially expressed among patients with DM, patients with other IIM, and healthy controls (HCs).MethodsIn total, three patients with DM, 10 patients with other IIM, and three HCs were included. Muscle biopsy specimens were collected for RNA‐sequencing. Gene ontology and pathway analyses were employed to characterize the biological processes and signaling pathways.ResultsCompared with HCs, 372 differentially expressed mRNAs were identified within the DM group, including 275 upregulated and 97 downregulated ones. Moreover, 692 differentially expressed lncRNAs were identified in the DM group compared with HCs, of which 407 were upregulated and 285 were downregulated. Bioinformatic analysis indicated that the type‐I interferon signaling pathway and biological processes of innate immunity were significantly influenced by the differentially expressed mRNAs. Notably, 11 of the top 20 upregulated mRNAs were involved in the type‐I interferon signaling pathway. Reverse transcription polymerase chain reaction analysis verified the RNA‐sequencing data. Target gene prediction analysis suggested that the lncRNA NONHSAG043573.2 potentially targeting transporter associated with antigen processing 1, a key regulator of interferon signaling genes, might play an important role in the pathogenesis of DM.ConclusionsOur study assessed the transcriptomic profiles of differentially expressed mRNAs and lncRNAs in the DM muscle tissue and revealed that the upregulated mRNAs are significantly involved in the innate immune response and the type‐I interferon signaling pathway, which might play important roles in the pathogenesis of DM.

Patient-Reported Health-Related Quality of Life, Anxiety and Depression in Patients with Inclusion Body Myositis: A Register-Based Cross-Sectional Study in Germany.

Inclusion body myositis (IBM) is a rare neuromuscular disease and the most prevalent idiopathic inflammatory myopathy (IIM) in patients aged older than 50 years. A systematic review has shown that no clear-cut conclusions can be drawn about the health-related quality of life (HRQoL) and mental health in IBM. We aimed to assess the HRQoL and mental health, to explore associated disease-related and socioeconomic factors as well as the utilization of psychological support in German IBM patients. This cross-sectional study included 82 patients registered in the German IBM patient registry. Patients had completed a survey battery including the EQ-5D-5L, the Individualized Neuromuscular Quality of Life (INQoL) and the Hospital Anxiety and Depression Scale German version (HADS-D). The physical HRQoL dimension was suggested to be most relevant. Most impaired life domains of HRQoL were mobility, independence, and activities. We identified significant differences in the total INQoL score for the degree of disability and care level as well as in depression for the degree of disability (p < 0.05), respectively. Most patients indicated no symptoms of anxiety (64.6%) and depression (62.2%). A more need-oriented psychological support in German IBM patients, reporting doubtful or definite anxiety or depression, could be suggested.

Leveraging Genomic and Bioinformatic Analysis to Enhance Drug Repositioning for Dermatomyositis.

Dermatomyositis (DM) is an autoimmune disease that is classified as a type of idiopathic inflammatory myopathy, which affects human skin and muscles. The most common clinical symptoms of DM are muscle weakness, rash, and scaly skin. There is currently no cure for DM. Genetic factors are known to play a pivotal role in DM progression, but few have utilized this information geared toward drug discovery for the disease. Here, we exploited genomic variation associated with DM and integrated this with genomic and bioinformatic analyses to discover new drug candidates. We first integrated genome-wide association study (GWAS) and phenome-wide association study (PheWAS) catalogs to identify disease-associated genomic variants. Biological risk genes for DM were prioritized using strict functional annotations, further identifying candidate drug targets based on druggable genes from databases. Overall, we analyzed 1239 variants associated with DM and obtained 43 drugs that overlapped with 13 target genes (JAK2, FCGR3B, CD4, CD3D, LCK, CD2, CD3E, FCGR3A, CD3G, IFNAR1, CD247, JAK1, IFNAR2). Six drugs clinically investigated for DM, as well as eight drugs under pre-clinical investigation, are candidate drugs that could be repositioned for DM. Further studies are necessary to validate potential biomarkers for novel DM therapeutics from our findings.

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

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). 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. 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. 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.

Magnetic resonance imaging findings of the lower limb muscles in anti-mitochondrial M2 antibody-positive myositis

Anti-mitochondrial M2 antibody (AMA-M2)-positive myositis is an idiopathic inflammatory myopathy (IIM). Of all patients with myositis, 2.5–19.5% have AMA-M2 antibodies. However, the detailed distribution of muscles affected in AMA-positive myositis is unknown. Therefore, we examined lower muscle magnetic resonance imaging (MRI) findings of patients with AMA-positive myositis. Among the 63 patients with IIM at our institute, 5 (7.9%) were positive for AMA-M2 antibodies. However, one was also positive for anti-Jo1 antibodies; therefore, four patients were finally participated in this study. All patients had high-intensity MRI signals in the proximal muscles, including the gluteus maximus and iliopsoas muscles, and in the thigh muscles, including the vastus lateralis, vastus medialis, adductor magnus, and semimembranosus muscles. Lower leg muscles were relatively spared. Fascial edema was observed in all patients and was also present in the lower leg muscles. Subcutaneous edema was observed, particularly in the proximal portion of the lower limbs. In AMA-positive myositis, proximal muscles, including the gluteus maximus, vastus lateralis, adductor magnus, and the semimembranosus, were markedly affected, while the lower leg muscles were relatively preserved. Additionally, fascial edema was evident even in lower leg muscles. Therefore, muscle MRI can be a useful diagnostic aid for AMA-positive myositis.

Autoantibodies Recognizing Specificity Protein 4 Co-occur With Anti-Transcription Intermediary Factor 1 and Are Associated With Distinct Clinical Features and Immunogenetic Risk Factors in Juvenile Myositis.

Autoantibodies recognizing specificity protein 4 (Sp4) were recently discovered in adults with idiopathic inflammatory myopathies (IIM). Anti-Sp4 autoantibodies co-occurred in patients with anti-transcription intermediary factor 1 (anti-TIF1) autoantibody-positive dermatomyositis (DM) and were associated with a reduced risk of cancer. In the present study, the prevalence and clinical features associated with anti-Sp4 autoantibodies in juvenile-onset IIM were investigated. Serum samples from 336 patients with juvenile myositis in a cross-sectional cohort and 91 healthy controls were screened for anti-Sp4 autoantibodies using enzyme-linked immunosorbent assay. Clinical characteristics, outcomes, and HLA alleles of those with and those without anti-Sp4 autoantibodies were compared. Anti-Sp4 autoantibodies were present in 23 patients (7%) with juvenile myositis and were not present in any of the controls. Anti-Sp4 autoantibodies were found among each clinical myositis subgroup. The frequency of TIF1 autoantibody positivity was significantly higher among those with anti-Sp4 autoantibodies (21 [91%] versus 92 [30%], P < 0.001). In the anti-TIF1 autoantibody-positive subgroup, Raynaud's phenomenon (8 [38%] versus 2 [2%], P < 0.001) was more common and peak aspartate aminotransferase was significantly lower in those with anti-Sp4 autoantibodies. None of the patients with anti-Sp4 autoantibodies required a wheelchair. Among White patients, DQA1*04 and DRB1*08 were associated with anti-Sp4 autoantibodies. Anti-Sp4 autoantibodies were found in patients with juvenile-onset IIM, predominantly those with coexisting anti-TIF1 autoantibodies. Patients with anti-Sp4 autoantibodies represent a phenotypic subset of anti-TIF1 autoantibody-positive myositis characterized by frequent Raynaud's phenomenon and less pronounced muscle involvement, similar to adults with these autoantibodies. Novel immunogenetic risk factors for White patients with IIM were identified among juveniles with anti-Sp4 autoantibodies.

Analytic Morphomics in Myositis-Related Interstitial Lung Disease

PurposeInterstitial lung disease (ILD) is the most common non-musculoskeletal manifestation of idiopathic inflammatory myopathies (IIM). Identification of body composition change may enable early intervention to improve prognosis. We investigated muscle quantity and quality derived from cross-sectional imaging in IIM, and its relationship to ILD severity.MethodsA retrospective cohort study assessing IIM of ILD patients (n = 31) was conducted. Two datasets separated in time were collected, containing demographics, biochemical data, pulmonary function testing and thoracic CT data. Morphomic analysis of muscle quantity (cross-sectional area) and quality (density in Hounsfield Units) on thoracic CT were analysed utilising a web-based tool allowing segmentation of muscle and fat. Bilateral erector spinae and pectoralis muscle (ESM&PM) were measured at defined vertebral levels.ResultsFVC and DLCO decreased but within acceptable limits of treatment response (FVC: 83.7–78.7%, p < 0.05, DLCO 63.4–60.6%, p < 0.05). The cross-sectional area of the PM and ESM increased (PM: 39.8 to 40.7 cm2, p = 0.491; ESM: 35.2 to 39.5 cm2, p = 0.098). Density significantly fell for both the PM and ESM (PM: 35.3–31 HU, p < 0.05; ESM: 38–33.7, p < 0.05). Subcutaneous fat area increased from 103.9 to 136.1 cm2 (p < 0.05), while the visceral fat area increased but not reaching statistical significance. The change in PM density between time points demonstrated an inverse correlation with DLCO (p < 0.05, R = − 0.49).ConclusionPatients with IIM ILD demonstrated significant body composition changes on CT imaging unlikely to be detected by traditional measurement tools. An increase in muscle area with an inverse decrease in density suggests poor muscle quality.

Fever in the initial stage of IIM patients: an early clinical warning sign for AE-ILD

BackgroundFever is a common symptom of Idiopathic inflammatory myopathies (IIM). However, the exact correlation between fever and the prognosis of IIM is still unclear. This study aims to clarify if the IIM patients initiated with fever are associated with poorer outcomes.MethodsThis was a single-center retrospective cohort study. Data were collected from 79 newly diagnosed, treatment-naive IIM patients in the Affiliated Wuxi People’s Hospital of Nanjing Medical University (Wuxi, Jiangsu, China) from November 2016 to June 2020. According to the presence or absence of fever at the onset, the IIM patients were divided into two groups(fever group n = 28, without fever group n = 51) Clinical characteristics, laboratory data, treatment, and outcomes were recorded. The Kaplan-Meier and log-rank tests were used to compare the all-cause mortality, relapse rate, and acute exacerbation of interstitial lung disease (AE-ILD) incidence. The association of fever with the outcomes was assessed in the unadjusted and adjusted forward logistic regression model.ResultsCompared with the non-fever group, the age at onset of the fever group was higher, and mechanic’s hands (MH) and interstitial lung disease (ILD) were more common. Systemic inflammation (CRP and ESR) was significantly higher in the fever group, while the level of albumin(ALB) and muscle enzymes were lower. The fever group seemed to be received more aggressive treatment, with higher dose glucocorticoids and higher rates of intravenous immunoglobulins(IVIG) use. The all-cause mortality rate and the incidence rate of AE-ILD were higher in the fever group. Even adjusted for the age at onset and treatments, fever was significantly associated with AE-ILD and all-cause mortality.ConclusionOur study has demonstrated that fever at initial diagnosis is associated with AE-ILD and mortality. Fever should serve as an early clinical warning sign for poor outcomes in IIM patients.

Anti-Cytosolic 5'-Nucleotidase 1A in the Diagnosis of Patients with Suspected Idiopathic Inflammatory Myopathies: An Italian Real-Life, Single-Centre Retrospective Study.

Anti-cytosolic 5'-nucleotidase 1A (anti-cN1A) antibodies were proposed as a biomarker for the diagnosis of inclusion body myositis (IBM), but conflicting specificity and sensitivity evidence limits its use. Our study aimed to assess the diagnostic accuracy of anti-cN1A in a cohort of patients who underwent a myositis line immunoassay for suspected idiopathic inflammatory myopathies (IIM). We also assessed the agreement between two testing procedures: line immunoassay (LIA) and enzyme-linked immunoassay (ELISA). We collected retrospective clinical and serological data for 340 patients who underwent a myositis antibody assay using LIA (EUROLINE Autoimmune Inflammatory Myopathies 16 Ag et cN-1A (IgG) line immunoassay) and verification with an anti-cN1A antibody assay using ELISA (IgG) (Euroimmun Lubeck, Germany). The serum samples of 20 (5.88%) patients (15 females, 5 males, mean age 58.76 ± 18.31) tested positive for anti-cN1A using LIA, but only two out of twenty were diagnosed with IBM. Seventeen out of twenty tested positive for anti-cN1A using ELISA (median IQR, 2.9 (1.9-4.18)). Our study suggests excellent concordance between LIA and ELISA for detecting anti-cN1A antibodies. LIA may be a rapid and useful adjunct, and it could even replace ELISA for cN1A assay. However, the high prevalence of diseases other than IBM in our cohort of anti-cN1A-positive patients did not allow us to consider anti-cN1A antibodies as a specific biomarker for IBM.

Myositis-associated interstitial lung disease.

In idiopathic inflammatory myopathies (IIMs), interstitial lung disease (ILD) is common and the autoantibody profile, made up of myositis-specific and myositis-associated (MSA and MAA) antibodies, can predict the clinical phenotype and progression over time. This review will focus on the characteristics and management of antisynthetase syndrome related ILD and anti-MDA5 positive ILD, which are the most clinically relevant subtypes. The prevalence of ILD in IIM has been estimated in Asia, North America and Europe at 50, 23 and 26%, respectively, and is increasing. In antisynthetase syndrome related ILD, the clinical presentation, progression and prognosis varies among anti-ARS antibodies. ILD is more common and severe in patients with anti-PL-7/anti-PL-12 antibodies when compared with anti Jo-1 patients. The prevalence of anti-MDA5 antibodies is higher in Asians (11-60%) than in whites (7-16%). Sixty-six percent of antisynthetase syndrome patients had 'chronic ILD' compared with the more rapidly progressive ILD (RP-ILD) seen in 69% of patients with anti-MDA5 antibodies. ILD is most common in the antisynthetase subtype of IIM and can be a chronic indolent or RP- ILD. The MSA and MAAs are associated with different clinical phenotypes of ILD. Treatments typically involve combinations of corticosteroids and other immunosuppressants.

18F]FDG-PET/CT in Idiopathic Inflammatory Myopathies: Retrospective Data from a Belgian Cohort.

[18F]FDG-PET/CT is a useful tool for diagnosis and cancer detection in idiopathic inflammatory myopathies (IIMs), especially polymyositis (PM) and dermatomyositis (DM). Data deriving from Europe are lacking. We describe [18F]FDG-PET/CT results in a Belgian cohort with IIMs, focusing on patients with PM and DM. All of the cases of IIMs admitted between December 2010 and January 2023 to the Cliniques Universitaires Saint-Luc (Belgium) were retrospectively reviewed. In total, 44 patients were identified with suspected IIMs; among them, 29 were retained for final analysis. The mean age of the retained patients was 48.7 years; 19 patients were female (65.5%). Twenty-two patients had DM and seven had PM. The mean serum creatinine kinase (CK) and the mean CRP levels were 3125 UI/L and 30.3 mg/L, respectively. [18F]FDG-PET/CT imaging was performed for 27 patients, detecting interstitial lung diseases (ILDs) in 7 patients (25.9%), cancer in 3 patients (11.1%), and abnormal muscle FDG uptake compatible with myositis in 13 patients (48.1%). All of the patients who were detected to have ILDs via PET/CT imaging were confirmed using a low-dose lung CT scan. Among the patients who were detected to have abnormal muscle FDG uptake via PET/CT scans (13/28), the EMG was positive in 12 patients (p = 0.004), while the MRI was positive in 8 patients (p = 0.02). We further observed that there was a significantly higher level of CK in the group with abnormal muscle FDG uptake (p = 0.008). Our study showed that PET/CT is useful for detecting cancer and ILDs. We showed that the detection of abnormal muscle uptake via PET/CT was in accordance with EMG and MRI results, as well as with the mean CK value, and that the presence of dyspnea was significantly associated with the presence of ILDs detected via PET/CT imaging (p = 0.002).