Case report: Multi-antibody-positive myasthenia gravis concomitant myositis associated with thymoma.

Myasthenia gravis (MG) and idiopathic inflammatory myopathy (IIM) are autoimmune diseases of the nervous system, and their main clinical manifestation is muscle weakness. The concurrent presence of both conditions in the same patient is clinically rare and easily missed. Here, we report the case of a 74-year-old woman who went to the doctor with fluctuating weakness of the limbs and muscle pain. By analyzing the patient's history and the results of repeated frequency electrical stimulation, chest computed tomography, thigh muscle magnetic resonance imaging, serum antibody detection, lymph node biopsy, etc., she was finally diagnosed with MG-concomitant IIM with squamous cell carcinoma of the thymus. Acetylcholine receptor antibody, titin antibody, ryanodine receptor antibody, anti-JO-1 antibody, and Ro-52 antibody tests were positive. MG-concomitant IIM is often associated with thymoma. The immunopathology mechanism may be different from that of pure MG or IIM, which needs further research.

Adenosine A2B receptor activation regulates the balance between T helper 17 cells and regulatory T cells, and inhibits regulatory T cells exhaustion in experimental autoimmune myositis.

BACKGROUND: Idiopathic inflammatory myopathy (IIM) is a systemic autoimmune disease characterized by skeletal muscle involvement. This study aimed to investigate the role of adenosine receptor signalling pathways in the development of experimental autoimmune myositis (EAM). METHODS: An ecto-5'-nucleotidase (CD73) inhibitor, adenosine receptor agonists, a hypoxia-inducible factor-1α (HIF-1α) inhibitor or a vehicle were administered to control and EAM mice. Murine splenic CD4+ or regulatory T cells (Tregs) were isolated using magnetic beads and subsequently stimulated with an adenosine A2B receptor agonist, a HIF-1α inhibitor, or vehicle in vitro. In cross-sectional studies, we collected 64 serum samples (69% female, 49 ± 9 years), 63 peripheral blood samples (70% female, 50 ± 11 years), and 34 skeletal muscle samples (71% female, 63 ± 6 years) from patients with IIM. Additionally, 35 serum samples and 30 peripheral blood samples were obtained from age- and sex-matched healthy controls, and six quadriceps muscle samples were collected from patients with osteoarthritis to serve as the normal group. RESULTS: Patients with IIM exhibited increased CD73 [dermatomyositis (DM), polymyositis (PM): P < 0.01; immune-mediated necrotizing myopathy (IMNM): P < 0.0001] and adenosine deaminase (ADA) expression (DM: P < 0.001; PM, IMNM: P < 0.0001) in the skeletal muscles, and serum ADA levels [56.7 (95% CI: 53.7, 58.7) vs. 198.8 (95% CI: 186.2, 237.3) ng/µL, P < 0.0001]. Intervention with a CD73 inhibitor exacerbated (P = 0.0461), whereas adenosine receptor agonists (A1: P = 0.0009; A2B: P < 0.0001; A3: P = 0.0001) and the HIF-1α inhibitor (P = 0.0044) alleviated skeletal muscle injury in EAM mice. Elevated expression of programmed cell death protein-1 (PD1: P = 0.0023) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3: P < 0.0001) in skeletal muscles of patients with IIM were correlated with creatine kinase levels (PD1, r = 0.7072, P < 0.0001; TIM3, r = 0.4808, P = 0.0046). PD1+CD4+ (r = 0.3243, P = 0.0115) and PD1+CD8+ (r = 0.3959, P = 0.0017) T cells were correlated with Myositis Disease Activity Assessment Visual Analogue Scale scores (muscle) in IIM. The exhausted Tregs were identified in the skeletal muscles of patients with IIM. Activation of the A2B adenosine receptor downregulated HIF-1α (protein or mRNA level, P < 0.01), resulting in decreased T helper cell 17 (Th17) (13.58% vs. 5.43%, P = 0.0201) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3)+ Th17 (16.32% vs. 6.73%, P = 0.0029), decreased exhausted Tregs (PD1+ Tregs: 53.55% vs. 40.28%, P = 0.0005; TIM3+ Tregs: 3.93% vs. 3.11%, P = 0.0029), and increased Tregs (0.45% vs. 2.89%, P = 0.0006) in EAM mice. CONCLUSIONS: The exhausted T cells may be pathogenic in IIM, and the activation of adenosine A2B receptor signalling pathway can regulate Th17/Treg balance and inhibit Tregs exhaustion, thereby slowing EAM disease progression.

[Peripheral neuroimmunological diseases - Neuropathological insights and clinical perspectives]. / Periphere neuroimmunologische Erkrankungen ­ neuropathologische Einsichten und klinische Perspektiven.

This article deals with peripheral neuroimmunological diseases and briefly outlines the currently most important aspects and treatment developments. Idiopathic inflammatory myopathies have different mechanisms of development, manifestations and prognoses. New classification systems and more specific treatment concepts have been developed. The IIMs include different subgroups. These entities can have specific autoantibodies. Diagnostically, a muscle biopsy is generally desirable for a precise diagnosis and is essential in unclear cases. Primary systemic vasculitides can be divided into different groups based on the predominant pattern of involvement, while secondary vasculitides and single organ vasculitides are also differentiated. Vasculitic myopathy cannot be equated with myositis and a reliable distinction is currently only possible by a muscle biopsy. Treatment concepts should be developed on an interdisciplinary basis. Chronic inflammatory demyelinating polyneuropathy is the most frequent immune-mediated neuropathy and is characterized by a predominant demyelination of the motor and sensory nerves. The disease course runs in phases or is progressive and leads to significant disability and reduction in quality of life, despite current standard treatment. Novel treatment approaches are currently undergoing clinical trials. Myasthenia gravis, with the leading symptom of exercise-induced muscle weakness, is caused by autoantibodies against structures of the neuromuscular endplate. Autoantibody testing is the most important pillar in the diagnosis and is now also increasingly guiding treatment decisions. Overall, peripheral neuroimmunological diseases represent a heterogeneous group. Increasing knowledge of the pathophysiology is the key to numerous developments in diagnostics and treatment, which could lead to far-reaching practical changes in the future.

Association of anti-Ro-52 antibodies with occurrence of interstitial lung disease in patients with idiopathic inflammatory myopathy.

BACKGROUND: Anti-Ro-52 antibodies have been associated with interstitial lung disease (ILD) in various autoimmune diseases. However, their role in ILD among patients with idiopathic inflammatory myopathies (IIMs) is relatively underexplored. This study aimed to investigate the association between anti-Ro-52 antibodies and the occurrence of ILD in individuals with IIMs. METHODS: This retrospective observational study included 604 patients who underwent myositis autoantibody testing between July 2018 and January 2021 at our hospital and were diagnosed with either IIMs or IIM-mimics. Comparative analyses were conducted between IIMs and IIM-mimics, as well as within the IIM group between cases with and without ILD. Logistic regression or Firth's logistic regression analyses were employed to assess the risk of ILD development in different IIM subgroups and myositis antibody categories. RESULTS: This study included 190 patients with IIM and 414 patients with IIM-mimics. Patients with IIM demonstrated higher incidence of ILD, concurrent autoimmune disease, and a greater likelihood of various myositis autoantibodies when compared to the IIM-mimics group. Within the IIM patient cohort, those with ILD exhibited a later age of onset of IIM, an increased mortality rate, and a more frequent presence of anti-aminoacyl-tRNA synthetase (ARS) antibodies compared to those without ILD. The presence of any myositis-specific antibody (MSA) was associated with a six-fold increased risk of ILD, while dual positivity for MSA and anti-Ro-52 antibodies conferred a twenty-fold risk. Anti-ARS antibodies carried a 14-fold increased risk of ILD, which escalated to 38-fold in cases of dual positivity for anti-ARS and anti-Ro-52 antibodies. Anti-Ro-52 antibodies alone increased the risk eight-fold. CONCLUSIONS: Among patients with IIM, the presence of ILD was linked to higher mortality. Certain autoantibodies, notably anti-ARS and anti-Ro-52 antibodies, were associated with an increased risk of ILD. The greatest risk of ILD was observed in cases of dual positivity for anti-ARS and anti-Ro-52 antibodies.

Clinico-sero-pathological profiles and risk prediction model of idiopathic inflammatory myopathy (IIM) patients with different perifascicular changes.

AIMS: To explore the clinico-sero-pathological characteristics and risk prediction model of idiopathic inflammatory myopathy (IIM) patients with different muscular perifascicular (PF) changes. METHODS: IIM patients in our center were enrolled and the clinico-sero-pathological data were retrospectively analyzed. A decision tree model was established through machine learning. RESULTS: There were 231 IIM patients enrolled, including 53 with perifascicular atrophy (PFA), 39 with perifascicular necrosis (PFN), and 26 with isolated perifascicular enhancement of MHC-I/MHC-II (PF-MHCn). Clinically, PFA patients exhibited skin rashes and dermatomyositis-specific antibodies (DM-MSAs, 74.5%) except for anti-Mi2. PFN patients showed the most severe muscle weakness, highest creatine kinase (CK), anti-Mi2 (56.8%), and anti-Jo-1 (24.3%) antibodies. PF-MHCn patients demonstrated negative MSAs (48.0%) and elevated CK. Histopathologically, MAC predominantly deposited on PF capillaries in PFA but on non-necrotic myofiber in PFN (43.4% and 36.8%, p < 0.001). MxA expression was least in PF-MHCn (36.0% vs. 83.0% vs. 63.2%, p < 0.001). The decision tree model could effectively predict different subgroups, especially PFA and PFN. CONCLUSIONS: Three types of PF change of IIMs representing distinct clinico-serological characteristics and pathomechanism. Undiscovered MSAs should be explored especially in PF-MHCn patients. The three pathological features could be accurately predicted through the decision tree model.

A Case of COVID-19-Triggered Polymyositis Leading to Rhabdomyolysis.

SARS-COVID-19 is known to manifest with a wide variety of symptoms, most of which are respiratory. Myalgias are a common symptom of COVID-19, but cases of severe virus-induced inflammatory muscle injury leading to rhabdomyolysis and polymyositis have also been reported. Here, we present and discuss a case of a 56-year-old woman who presented with an initial presentation of COVID-19 infection with inflammatory polymyositis leading to rhabdomyolysis. The patient was first treated for rhabdomyolysis with aggressive fluid resuscitation with intravenous normal saline without improvement in symptoms. She was then started on high-dose intravenous methylprednisolone for presumed immune-mediated polymyositis. An MRI of the bilateral lower extremities and a biopsy of the left thigh confirmed inflammatory myositis. After the initiation of steroids, liver function tests and creatinine kinase levels trended down, and symptoms improved. The patient was discharged with a prednisone taper and completely recovered at a follow-up six months later. Post-COVID severe musculoskeletal involvement, including polymyositis or rhabdomyolysis, is rare, with only a few other cases published so far. Viral myositis, supported by myopathological evidence, should be considered carefully in patients with a recent COVID-19 infection after ruling out more common causes of myositis. Some proposed mechanisms include direct infection of the muscle or an environmental event triggering autoimmunity. Treatment generally involves corticosteroids that are gradually tapered.

Differences in the autoantibody phenotypes and long-term outcomes between juvenile- and adult-idiopathic inflammatory myopathies.

OBJECTIVE: To investigate differences in autoantibodies, clinical features, and long-term outcomes between juvenile-idiopathic inflammatory myopathy (IIM) and adult-IIM METHODS: Autoantibodies, clinical characteristics, and drug-free conditions for a maximum of 20 years were retrospectively analyzed in 320 Japanese IIM patients (juvenile-IIM, n = 34; adult-IIM, n = 286) using the Kyoto University Registry. RESULTS: Autoantibodies observed in juvenile-IIM were anti-TIF1-γ (15 %), anti-MDA-5 (15 %), anti-ARS (9 %), and anti-NXP-2 (6 %). Those observed in adult-IIM were anti-ARS (32 %), anti-MDA-5 (23 %), anti-TIF1-γ (8 %), anti-SRP (8 %), anti-Mi-2 (2 %), and anti-NXP-2 (1 %). The cumulative drug-free condition rate was higher in juvenile-IIM than in adult-IIM up to 20 years (juvenile-IIM vs. adult-IIM, 34 % vs. 18 %, p = 0.0016). Anti-TIF1-γ was associated with lesser muscle symptoms (60 % vs. 90 %), malignancy (0 % vs. 57 %), and glucocorticoid use (40 % vs. 86 %) in juvenile-IIM compared to adult-IIM, while juvenile-IIM more achieved drug-free conditions (60 % vs. 25 %). Both juvenile-IIM and adult-IIM with anti-MDA-5 demonstrated a high frequency of amyopathic dermatomyositis, interstitial lung disease (ILD), and multi-immunosuppressive therapy, with high drug-free conditions (50 % vs. 49 %). Both juvenile-IIM and adult-IIM with anti-ARS showed frequent skin rashes, muscle symptoms, and ILD, frequent need for multi-immunosuppressive therapy, and low drug-free condition rates (0 % vs. 3 %). Both juvenile-IIM and adult-IIM with anti-NXP-2 showed frequent skin rashes and muscle symptoms, low ILD frequency, and frequent use of methotrexate and glucocorticoids, which did not achieve drug-free conditions (0 % vs. 0 %). CONCLUSIONS: Drug-free condition was achieved more frequently in juvenile-IIM patients than adult-IIM patients. Specific autoantibodies were associated with different clinical characteristics and outcomes between juvenile-IIM and adult-IIM.

A protocol for scoping reviews on the role of whole-body and dedicated body-part magnetic resonance imaging for assessment of adult and juvenile idiopathic inflammatory myopathies.

Currently, standardized magnetic resonance imaging (MRI) scoring systems and protocols for assessment of idiopathic inflammatory myopathies (IIMs) in children and adults are lacking. Therefore, we will perform a scoping review of the literature to collate and evaluate the existing semi-quantitative and quantitative MRI scoring systems and protocols for the assessment and monitoring of skeletal muscle involvement in patients with IIMs. The aim is to compile evidence-based information that will facilitate the future development of a universal standardized MRI scoring system for both research and clinical applications in IIM. A systematic search of electronic databases (PubMed, EMBASE, and Cochrane) will be undertaken to identify relevant articles published between January 2000 and October 2023. Data will be synthesized narratively. This scoping review seeks to comprehensively summarize and evaluate the evidence on the scanning protocols and scoring systems used in the assessment of diagnosis, disease activity, and damage using skeletal muscle MRI in IIMs. The results will allow the development of consensus recommendations for clinical practice and enable the standardization of research methods for the MRI assessment of skeletal muscle changes in patients with IIMs.

Magnetic resonance imaging of the musculoskeletal system in the diagnosis of rheumatic diseases in the pediatric population.

Magnetic resonance imaging (MRI) of the musculoskeletal system is an examination increasingly performed for suspected juvenile idiopathic arthritis, chronic nonbacterial osteomyelitis and juvenile idiopathic inflammatory myopathies, as well as other rheumatic diseases of developmental age. T1-, T2- and PD-weighted with or without fat suppression or short tau inversion recovery/turbo inversion recovery magnitude (STIR/TIRM) sequences and post-contrast sequences are evaluated to diagnose pathological changes in the synovial membrane, subchondral bone marrow and surrounding soft tissues. Magnetic resonance imaging allows detection of synovitis, tenosynovitis, bursitis, and enthesitis as well as bone marrow edema and soft tissue edema. Several pediatric-specific MRI scoring systems have been developed and validated to standardize and facilitate the assessment of the extent of the inflammatory process and disease activity in MRI. Early detection of inflammatory changes allows the inclusion of comprehensive pharmacotherapy giving the possibility of permanent remission and objective measurement of the effectiveness of treatment.

Anti-FHL1 autoantibodies in adult patients with myositis: a longitudinal follow-up analysis.

OBJECTIVES: To determine prevalence and clinical associations of anti-FHL1 autoantibodies in patients with idiopathic inflammatory myopathies (IIM), and to evaluate autoantibody levels over time. METHODS: Sera at the time of diagnosis from patients with IIM (n = 449), autoimmune disease controls (DC, n = 130), neuromuscular diseases (NMD, n = 16) and healthy controls (HC, n = 100) were analyzed for anti-FHL1 autoantibodies by Enzyme-Linked ImmunoSorbent Assay (ELISA). Patients with IIM FHL1+ and FHL1- were included in a longitudinal analysis. Serum levels were correlated to disease activity. RESULTS: Autoantibodies to FHL1 were more frequent in patients with IIM (122/449, 27%) compared with DC (Autoimmune DC and NMD, 13/146, 9%, p< 0.001) and HC (3/100,3%, p< 0.001). Anti-FHL1 levels were higher in IIM [median (IQR)=0.62 (0.15-1.04)] in comparison with DC [0.22 (0.08-0.58)], HC [0.35 (0.23-0.47)] and NMD [0.48 (0.36-0.80)] p< 0.001. Anti-FHL1+ patients with IIM were younger at time of diagnosis compared with the anti-FHL1- group (p= 0.05) and were seronegative for other autoantibodies in 25%.In the first follow-up anti-FHL1+ sample 20/33 (60%) positive at baseline had turned negative for anti-FHL1 autoantibodies. Anti-FHL1 autoantibodies rarely appeared after initiating treatment. Anti-FHL1 autoantibody levels correlated with CK (r = 0.62, p= 0.01), disease activity measure MYOACT (n = 14, p= 0.004) and inversely with manual muscle test-8 (r=-0.59, p= 0.02) at baseline. CONCLUSIONS: Anti-FHL1 autoantibodies were present in 27% of patients with IIM, of these 25% were negative for other autoantibodies. Other autoimmune diseases had lower frequencies and levels. Anti-FHL1 levels often decreased with immunosuppressive treatment, correlated with disease activity measures at diagnosis and rarely appeared after start of treatment.

Predictive risk factors for one-year mortality in idiopathic inflammatory myopathy patients with interstitial lung disease: A retrospective, single-center cohort study.

Objectives: This study aimed to analyze the risk factors for mortality of idiopathic inflammatory myopathy (IIM) patients admitted with interstitial lung disease (ILD) to guide rapid and accurate judgment of clinical prognosis. Patients and methods: This retrospective, single-center cohort study was conducted with 135 participants (37 males, 98 females; mean age: 54.8±11.1 years; range, 24 to 85 years) between June 1, 2016, and June 30, 2021. The participants were categorized into the survival group (n=111) and nonsurvivors (n=24) according to whether they survived during the one-year follow-up. The independent risk factors for mortality in one year after discharge were analyzed. Receiver operating characteristic curve analysis was used to determine the accuracy of oxygenation index at baseline combined with pulmonary infection (PI) at follow-up to indicate death in IIM-ILD patients. Results: Compared to the survival group, nonsurvivors were older (p=0.006) and had a higher proportion of anti-MDA5 (melanoma differentiation-associated protein 5) positivity (p<0.001). The ILD duration was shorter (p=0.006), the oxygenation index was lower (p<0.001), and the intensive care unit occupancy rate (p<0.001) and ventilator utilization rate (p<0.001) were elevated in nonsurvivors compared to the survival group. Oxygenation index at baseline (odds ratio [OR]=1.021, 95% confidence interval [CI]: 1.001-1.023, p=0.040) and PI (clinical judgment) at follow-up (OR=16.471, 95% CI: 1.565-173.365, p=0.020) were found as independent risk factors for death in the year after discharge in IIM inpatients with ILD. An oxygenation index ≤279 mmHg at baseline combined with PI at follow-up exhibited a promising predictive value for all-cause death in IIM-ILD patients within one year. Conclusion: Oxygenation index at baseline and PI during follow-up were independent risk factors for death of IIM-ILD patients within one year after discharge. Patients with an oxygenation index ≤279 mmHg at baseline had an increased risk of death once they developed PI during the one-year follow-up.

Disease-specific autoantibody production in the lungs and salivary glands of anti-synthetase syndrome.

Interstitial lung disease is a common complication of anti-synthetase syndrome (ASS), and lymphocytic infiltration is often observed in the lesion. We have recently reported that disease-specific autoantibodies are produced by infiltrating lymphocytes in some autoimmune diseases. Here, we investigate the antigen specificity of B cells in the lung lesions of ASS patients. A total of 177 antibodies were produced from antibody-secreting cells in bronchoalveolar fluid (BALF) of three each of serum anti-Jo-1 and serum anti-EJ antibody-positive patients. Twelve to 30% and 50 to 62% of these antibodies were disease-specific autoantibodies, respectively. These autoantibodies recognized conformational epitopes of the whole self-antigen and had affinity maturations, indicating that self-antigens themselves are the target of humoral immunity. In addition, 100 antibodies were produced from two salivary gland tissues, obtained by chance, of ASS patients. Salivary glands are not generally recognized as lesions of ASS, but unexpectedly, ASS-related autoantibody production was also observed similar to that of BALF. Immunostaining confirmed the presence of ASS-related autoantibody-producing cells in salivary glands. Our results suggest that disease-specific autoantibody production at lesion sites is a common pathogenesis of autoimmune diseases, and that tissue-specific production of autoantibodies can provide insights regarding the distribution of organ manifestations in autoimmune diseases.

Immune-Mediated Necrotizing Myopathy Associated With Anti-signal Recognition Particle Antibody Complicated With Acute Respiratory Distress Syndrome: A Report of Two Cases.

Immune-mediated necrotizing myopathy (IMNM) represents a rare category of inflammatory myopathies characterized by more severe and rapid progression of symmetrical proximal muscle weakness. It is also marked by notably elevated serum muscle enzyme levels and distinct histological features, setting it apart from other types of myositis. Moreover, acute chronic lung respiratory dysfunction is a major comorbidity of great concern. We herein present two cases of IMNM associated with anti-signal recognition particle antibodies complicated by acute respiratory distress syndrome.

Prognostic significance of natural killer cell depletion in predicting progressive fibrosing interstitial lung disease in idiopathic inflammatory myopathies.

Objectives: Interstitial lung disease (ILD) is one of the common extramuscular involvement in idiopathic inflammatory myopathies (IIMs) (1). Several patients develop a progressive fibrosing ILD (PF-ILD) despite conventional treatment, resulting in a progressive deterioration in their quality of life (2). Here, we investigated the clinical and immune characteristics of IIM-ILD and risk factors for PF-ILD in IIM, mainly in anti-melanoma differentiation-associated protein 5 (anti-MDA5+) dermatomyositis (DM) and anti-synthetase syndrome (ASS). Methods: Here, a prospective cohort of 156 patients with IIM-ILD were included in the longitudinal analysis and divided into the PF-ILD (n=65) and non-PF-ILD (n=91) groups, and their baseline clinical characteristics were compared. Univariate and multivariate Cox analyses were performed to identify the variables significantly associated with pulmonary fibrosis progression in the total cohort, then anti-MDA5+ DM and ASS groups separately. Results: Peripheral blood lymphocyte counts, including T, B, and NK cell counts, were significantly lower in the PF-ILD group than in the non-PF-ILD group. This characteristic is also present in the comparison between patients with anti-MDA5+ DM and ASS. The multivariate Cox regression analysis revealed that age > 43.5 years [HR: 7.653 (95% CI: 2.005-29.204), p = 0.003], absolute NK cell count < 148 cells/µL [HR: 6.277 (95% CI: 1.572-25.067), p = 0.009] and absolute Th cell count < 533.2 cells/µL [HR: 4.703 (95% CI: 1.014-21.821), p = 0.048] were independent predictors of progressive fibrosing during 1-year follow-up for patients with anti-MDA5+ DM, while absolute count of NK cells < 303.3 cells/µL [HR: 19.962 (95% CI: 3.108-128.223), p = 0.002], absolute count of lymphocytes < 1.545×109/L [HR: 9.684 (95% CI: 1.063-88.186), p = 0.044], and ferritin > 259.45 ng/mL [HR: 6 (95% CI: 1.116-32.256), p = 0.037] were independent predictors of PF-ILD for patients with ASS. Conclusions: Patients with anti-MDA5+ DM and ASS have independent risk factors for PF-ILD. Lymphocyte depletion (particularly NK cells) was significantly associated with PF-ILD within 1-year of follow-up for IIM-ILD.

Effectiveness and safety of immunoadsorption as a rescue treatment of inflammatory myopathies: report of three cases and literature review.

Idiopathic inflammatory myopathy (IIM) summarizes rare, systemic autoimmune conditions primarily characterized by inflammatory damage to the skeletal muscle. Although primary damage occurs to the muscle, these IIM-related conditions involve other organs, including the skin, lungs, upper gastrointestinal tract, joints, and heart. While many patients have an adequate response to immunosuppressive treatment, some patients develop rapidly progressive and treatment-resistant life-threatening courses. Treatment-resistant IIM is challenging for the treating physician and requires interdisciplinary and individualized treatment approaches. Extracorporeal therapy is one option for rescue therapy, with immunoadsorption (IA) having proven more effective than plasma exchange regarding the removal of circulating antibodies. Despite its efficacy and desirable safety profile, the clinical value of IA use in IIM is understudied with no controlled trials reported. Here, we present a review of the current knowledge regarding the management of treatment-resistant IIM and the cases of three patients with treatment-resistant IIM (two with dermatomyositis and one with immune-mediated necrotizing myopathy) who have successfully been treated with IA. All patients responded well to the therapy and experienced no IA-related complications. Taken together, we found IA to be a safe and effective treatment option in treatment-resistant IIM.

Real-world implications of IMACS malignancy screening guidelines for idiopathic inflammatory myopathies: An evaluation of compliance and economic impact at a tertiary referral center.

AIM: An inaugural set of consensus guidelines for malignancy screening in idiopathic inflammatory myopathy (IIM) were recently published by an international working group. These guidelines propose different investigation strategies based on "high", "intermediate" or "standard" malignancy risk groups. This study compares current malignancy screening practices at an Australian tertiary referral center with the recommendations outlined in these guidelines. METHODS: We conducted a retrospective analysis of newly diagnosed IIM patients. Relevant demographic and clinical data regarding malignancy screening were recorded. Existing practice was compared with the guidelines using descriptive statistics; costs were calculated using the Australian Medicare Benefit Schedule. RESULTS: Of the 47 patients identified (66% female, median age: 63 years [IQR: 55.5-70], median disease duration: 4 years [IQR: 3-6]), only one had a screening-detected malignancy. Twenty patients (43%) were at high risk, while 20 (43%) were at intermediate risk; the remaining seven (15%) had IBM, for which the proposed guidelines do not recommend screening. Only three (6%) patients underwent screening fully compatible with International Myositis Assessment and Clinical Studies recommendations. The majority (N = 39, 83%) were under-screened; the remaining five (11%) overscreened patients had IBM. The main reason for guideline non-compliance was the lack of repeated annual screening in the 3 years post-diagnosis for high-risk individuals (0% compliance). The mean cost of screening was substantially lower than those projected by following the guidelines ($481.52 [SD 423.53] vs $1341 [SD 935.67] per patient), with the highest disparity observed in high-risk female patients ($2314.29/patient). CONCLUSION: Implementation of the proposed guidelines will significantly impact clinical practice and result in a potentially substantial additional economic burden.

Further expanding the phenotype of anti-Ku antibody associated disease in children and adolescents.

Anti-Ku autoantibodies are associated with several autoimmune inflammatory diseases. We aimed to review our anti-Ku positive pediatric patients in this study. Four pediatric patients (all female) who had anti-Ku positivity were included (Patients 1-2-3 with idiopathic inflammatory myopathy (IIM); Patient 4 with chronic urticaria). Patient 1 (onset:10.5 years) had proximal muscle weakness, Raynaud phenomenon, sclerodactyly, hyperpigmentation, joint contracture, and tenosynovitis. The disease course was progressive despite treatment with corticosteroids, intravenous immunoglobulin (IVIG), plasma exchange, and 11 different immunosuppressive drugs. Patient 2 (onset:15 years) presented with proximal muscle weakness, fatigue, weight loss. She recovered normal muscle strength after treatment with corticosteroids, IVIG, methotrexate, cyclosporine A, mycophenolate mofetil. Patient 3 (onset:10 years) had juvenile dermatomyositis with proximal muscle weakness, Gottron's papules, and calcinosis. She also had anti-NXP2 positivity. Remission was achieved with corticosteroids, methotrexate, azathioprine, and infliximab. Muscle biopsy findings revealed a variable spectrum of necrosis, regeneration, perifascicular pattern, and inflammation. Patient 4 had only chronic urticaria (onset: 6.5 years). The striking features of this series were heterogeneity in clinical presentations including solely chronic urticaria and IIM; variable response to immunosuppressive treatments; and histopathology revealing a spectrum of necrosis, regeneration and inflammatory infiltration. Expanding the spectrum of anti-Ku positivity will allow better understanding of anti-Ku-associated phenotype clusters.

Cluster analysis of clinical phenotypes in idiopathic inflammatory myopathy patients complicated with cardiac involvement.

OBJECTIVE: This study aimed to classify idiopathic inflammatory myopathy (IIM) patients with cardiac involvement (IIM-CI) into different categories based on their clinical phenotypes via cluster analysis and to explore their differences in outcomes. METHODS: IIM-CI patients admitted to Peking Union Medical College Hospital from January 2015 to June 2021 were retrieved. The clinical data, laboratory examinations, and treatment were retrospectively reviewed, and the outcome was traced. A second-order clustering method was employed for categorization. RESULTS: A total of 88 IIM-CI patients were enrolled in this study and were classified into two categories through cluster analysis. Category I consisted of patients who exhibited distinct cardiac structural and functional changes, such as enlargement of atriums and/or ventricles, along with the remarkable heart insufficiency biomarkers, whereas patients of category II displayed more widely systemic injuries and intensive skeletal muscle weakness. In comparison, pulmonary hypertension (58.8% vs 16.7%, p < 0.01), arrhythmia (82.4% vs 27.8%, p < 0.01), and positive serum anti-mitochondrial-M2 antibody (52.9% vs 5.6%, p < 0.01) were more prevalent in category I than in category II, and serum N-terminal pro-B-type natriuretic peptide levels (1703.5 pg/L vs 364.0 pg/L, p = 0.02) were significantly elevated in category I, whereas skeletal muscle weakness (50.0% vs 74.1%, p = 0.02), interstitial lung disease (20.6% vs 63.0%, p < 0.01), skin rash (11.8% vs 48.1%, p < 0.01), arthralgia (2.9% vs 27.8%, p < 0.01), fever (2.9% vs 27.8%, p < 0.01), and dysphagia (2.9% vs 22.2%, p < 0.01) were more common in category II patients. Heart failure was the primary cause of death in category I, but severe pneumonia was predominantly responsible for deaths in category II. CONCLUSION: Two categories of IIM-CI were identified based on clinical features with distinctive characteristics. Two categories exhibited differences in clinical manifestations, autoantibody profiles, and the primary cause of death.