Sporadic Inclusion Body Myositis Research Articles

Intramyocardial fatty infiltration lesion in sporadic inclusion body myositis: a case report.

Sporadic inclusion body myositis (sIBM), the most common inflammatory muscle disorder in adults over 50 years, is often misdiagnosed due to its gradual onset and its common but unspecific muscle weakness in older adults. Diagnosis relies on clinical, radiological, and pathological features. Cardiac involvement is rare, prompting this case description and a comprehensive literature analysis. A 73-year-old woman diagnosed with sIBM in 2021 through muscle biopsy had been experiencing muscular symptoms since 2015. Her condition progressively worsened, affecting daily activities. Annual follow-ups revealed a moderate obstructive syndrome on respiratory testing, prompting a cardiac evaluation. Cardiac magnetic resonance (CMR) imaging identified intramyocardial lesions consistent with fatty infiltration, highlighting the interest of advanced imaging in sIBM management. Cardiac involvement in sIBM is presumed rare compared to other idiopathic inflammatory myopathies, though the exact frequency remains unclear. Early identification of heart alterations by CMR in sIBM can be prognostically valuable, guiding follow-up and interventions. However, literature on this subject is limited to small cohort studies and case reports describing complications. Given the slow progression of sIBM and the limited efficacy of current treatments, the discovery of myocardial lesions could warrant closer cardiological monitoring. Larger cohort studies are needed to explore potential new therapeutic approaches. Our case underscores the importance of CMR in detecting subtle cardiac manifestations in sIBM and illustrates the potential prognostic value of cardiac assessment in the management of sIBM.

Features of Swallowing Function in Sporadic Inclusion Body Myositis: Preliminary Evidence Using Well-Tested Assessment Frameworks.

Evidence surrounding swallowing impairment in sporadic inclusion body myositis (IBM) is based on nonstandardized and nonvalidated assessment methods. We investigated (a) IBM's impact on swallowing function and oral intake status using well-tested assessment frameworks; (b) changes in swallowing over time; and (c) age, sex, and swallowing impairment severity's influence on oral intake status. We conducted a secondary analysis of Modified Barium Swallow Impairment Profile (MBSImP) and Functional Oral Intake Scale (FOIS) data from 13 patients with IBM (seven females; Mage = 60.2 [±13.6] years) and 13 age- and sex-matched healthy controls. We compared MBSImP Overall Impression (OI), Oral Total (OT), Pharyngeal Total (PT), and FOIS scores between groups. Specific to the IBM cohort, we analyzed repeated OT and PT scores and calculated whether age, sex, and OT and PT scores predicted FOIS scores. The IBM cohort demonstrated poorer OI scores across six swallowing components than healthy controls (each p < .05). Unlike OT scores (p = .84), PT (p = .033) and FOIS (p < .001) scores were worse in the IBM cohort. Repeated OI scores revealed changes in three swallowing components (each p < .05), but repeated OT (p = .16) and PT (p = .30) scores did not significantly change. Age, sex, and OT and PT scores did not influence FOIS scores (each p > .05). Pharyngeal impairments were most prominent in the IBM cohort, and their oral intake status was adversely affected. Our preliminary data showcase the application of robust assessment methods to investigate swallowing function in IBM, enhancing standardization and comparability across studies. https://doi.org/10.23641/asha.27165450.

Volumetric muscle composition analysis in sporadic inclusion body myositis using fat-referenced magnetic resonance imaging: Disease pattern, repeatability, and natural progression.

Fat-referenced magnetic resonance imaging (MRI) has emerged as a promising volumetric technique for measuring muscular volume and fat in neuromuscular disorders, but the experience in inflammatory myopathies remains limited. Therefore, this work aimed at describing how sporadic inclusion body myositis (sIBM) manifests on standardized volumetric fat-referenced MRI muscle measurements, including within-scanner repeatability, natural progression rate, and relationship to clinical parameters. Ten sIBM patients underwent whole-leg Dixon MRI at baseline (test-retest) and after 12 months. The lean muscle volume (LMV), muscle fat fraction (MFF), and muscle fat infiltration (MFI) of the quadriceps, hamstrings, adductors, medial gastrocnemius, and tibialis anterior were computed. Clinical assessments of IBM Functional Rating Scale (IBMFRS) and knee extension strength were also performed. The baseline test-retest MRI measurements were used to estimate the within-subject standard deviation (sw). 12-month changes were derived for all parameters. The MRI measurements showed high repeatability in all muscles; sw ranged from 2.7 to 18.0 mL for LMV, 0.7-1.3 percentage points (pp) for MFF, and 0.2-0.7 pp for MFI. Over 12 months, average LMV decreased by 7.4% while MFF and MFI increased by 3.8 pp and 1.8 pp, respectively. Mean IBMFRS decreased by 2.4 and mean knee extension strength decreased by 32.8 N. The MRI measurements showed high repeatability and 12-month changes consistent with muscle atrophy and fat replacement as well as a decrease in both muscle strength and IBMFRS. Our findings suggest that fat-referenced MRI measurements are suitable for assessing disease progression and treatment response in inflammatory myopathies.

Quantitative muscle MRI in sporadic inclusion body myositis (sIBM): A prospective cohort study.

Sporadic inclusion body myositis (sIBM) is the predominant idiopathic inflammatory myopathy (IIM) in older people. Limitations of classical clinical assessments have been discussed as possible explanations for failed clinical trials, underlining the need for more sensitive outcome measures. Quantitative muscle MRI (qMRI) is a promising candidate for evaluating and monitoring sIBM. Longitudinal assessment of qMRI in sIBM patients. We evaluated fifteen lower extremity muscles of 12 sIBM patients (5 females, mean age 69.6, BMI 27.8) and 12 healthy age- and gender-matched controls. Seven patients and matched controls underwent a follow-up evaluation after one year. Clinical assessment included testing for muscle strength with Quick Motor Function Measure (QMFM), IBM functional rating scale (IBM-FRS), and gait analysis (6-minute walking distance). 3T-MRI scans of the lower extremities were performed, including a Dixon-based sequence, T2 mapping and Diffusion Tensor Imaging. The qMRI-values fat-fraction (FF), water T2 relaxation time (wT2), fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (λ1), and radial diffusivity (RD) were analysed. Compared to healthy controls, significant differences for all qMRI parameters averaged over all muscles were found in sIBM using a MANOVA (p < 0.001). In low-fat muscles (FF < 10%), a significant increase of wT2 and FA with an accompanying decrease of MD, λ1, and RD was observed (p≤0.020). The highest correlation with clinical assessments was found for wT2 values in thigh muscles (r≤-0.634). Significant changes of FF (+3.0%), wT2 (+0.6 ms), MD (-0.04 10-3mm2/s), λ1 (-0.05 10-3mm2/s), and RD (-0.03 10-3mm2/s) were observed in the longitudinal evaluation of sIBM patients (p≤0.001). FA showed no significant change (p = 0.242). qMRI metrics correlate with clinical findings and can reflect different ongoing pathophysiological mechanisms. While wT2 is an emerging marker of disease activity, the role of diffusion metrics, possibly reflecting changes in fibre size and intracellular deposits, remains subject to further investigations.

Anti-HMGCR myopathy: Diversity of clinical presentations in a national cohort in New Zealand

AimsWe describe the varied clinical presentations, barriers in diagnosis and outcomes of anti-HMGCR myopathy in a large national cohort. MethodsAdults found positive for serum anti-HMGCR autoantibodies via line blot or enzyme-immunoassay followed by immunoprecipitation were included in the study. ResultsOf 75 patients identified, the records of 72 (96 %) described weakness as the presenting symptom. The records of 65 gave a reliable description of proximal weakness. In 22/65 (33.8 %) the weakness was described as predominantly or solely lower limb weakness. Forty-five of 75 (60 %) presented with a subacute onset (duration of symptoms >4 weeks -≤6 months), whilst 22/75 (29.3 %) presented with a more indolent chronic onset (duration of symptoms >6 months). Eighteen of 75 (24 %) suffered falls and 2/75 (2.7 %) had “general decline”. In three patients no weakness was described: two presented with myalgia and one with a skin rash characterized as Jessner lymphocytic skin rash. Median creatine kinase at presentation was 7337 U/L (range 1050–25,500). Muscle biopsy was performed in 38 (50.7 %). Associated malignancy was infrequent. Four patients recovered without immunosuppression. Five-year and 10-year survival was 92.7 % (95 % CI 80.6–97.4 %), and 82.5 % (95 % CI 61.2–92.8 %) respectively. ConclusionRecurrent falls, a long prodrome and dominant lower limb proximal weakness were common in this anti-HMGCR myopathy cohort. These features overlap with frailty syndrome and sporadic inclusion body myositis emphasizing the importance of considering anti-HMGCR myopathy in that clinical context. A minority of patients recover after statin withdrawal alone.

Mitochondrial defects in sporadic inclusion body myositis-causes and consequences.

Sporadic inclusion body myositis (sIBM) is a distinct subcategory of Idiopathic Inflammatory Myopathies (IIM), characterized by unique pathological features such as muscle inflammation, rimmed vacuoles, and protein aggregation within the myofibers. Although hyperactivation of the immune system is widely believed as the primary cause of IIM, it is debated whether non-immune tissue dysfunction might contribute to the disease's onset as patients with sIBM are refractory to conventional immunosuppressant treatment. Moreover, the findings that mitochondrial dysfunction can elicit non-apoptotic programmed cell death and the subsequent immune response further support this hypothesis. Notably, abnormal mitochondrial structure and activities are more prominent in the muscle of sIBM than in other types of IIM, suggesting the presence of defective mitochondria might represent an overlooked contributor to the disease onset. The large-scale mitochondrial DNA deletion, aberrant protein aggregation, and slowed organelle turnover have provided mechanistic insights into the genesis of impaired mitochondria in sIBM. This article reviews the disease hallmarks of sIBM, the plausible contributors of mitochondrial damage in the sIBM muscle, and the immunological responses associated with mitochondrial perturbations. Additionally, the potential application of mitochondrial-targeted chemicals as a new treatment strategy to sIBM is explored and discussed.

Sporadic Inclusion Body Myositis

Sporadic inclusion body myositis (sIBM) is an intractable and progressive skeletal muscle disease of unknown etiology. Muscle biopsy typically reveals endomysial inflammation, invasion of mononuclear cells into non-necrotic fibers, and rimmed vacuoles, suggesting that inflammation and degeneration co-exist in the pathomechanism. According to a nationwide survey conducted by a research team of the Ministry of Health, Labor, and Welfare, the number of patients is increasing in Japan as well. The clinical progression shows a slow and chronic deterioration. sIBM is usually diagnosed five years after onset. Muscle weakness and atrophy in the quadriceps, wrist flexors, and finger flexors are typical neurological findings of sIBM. Dysphagia and asymmetric weakness are often found. Serum creatine kinase is usually below 2,000 IU/L. sIBM is generally refractory to current therapy, such as steroids or immunosuppressants. Understanding the pathomechanism of sIBM is crucial for developing effective therapeutic strategies.

P150 Diagnostic utility of anti-cN1A autoantibody testing in sporadic inclusion body myositis

Abstract Background/Aims Sporadic inclusion body myositis (sIBM) is the most common acquired myopathy in patients aged over 50 years. Diagnostic criteria encompass clinical, biochemical, and myopathological features. Certain myopathological features possess high specificity but low sensitivity; reliance on such findings may lead to delayed or misdiagnoses. The discovery of autoantibodies against cytosolic 5'-Nucleotidase 1A (cN1A) in sIBM patients suggests an autoimmune component in pathogenesis, but the inclusion of this autoantibody in diagnostic criteria remains uncertain. Additionally, optimal testing methodology has not been established, with varying techniques (e.g., ELISA/line-blot) in use. We assessed antibody profiles in an sIBM cohort and reviewed diagnoses in anti-cN1A positive patients. Methods This study was based at the Northern Care Alliance NHS Foundation Trust which hosts a tertiary neuromuscular referral service for the North-West of England. Data sources included myositis clinic and immunology results databases. All patients tested using a validated myositis line-blot immunoassay (EUROLINE 16 Antigen et cN1A [EUROIMMUN]) November 2021-April 2023 were included. Diagnoses of all tested patients were identified through case-note review. Sensitivity and specificity metrics were calculated based on diagnosis and anti-cN1A antibody status. Results The total number of patients tested for anti-cN1A was 495. Of these, 10 patients had a diagnosis of sIBM. The true-positive and false-negative rates were both 50% (n = 5 each). Of the 485 patients who did not have sIBM, true-negativity was 97.52% (n = 473) and false-positivity 2.47% (n = 12). Overall, anti-cN1A had a sensitivity of 50%, specificity of 97.52%, positive predictive value of 29.41% and negative predictive value of 98.95% for sIBM (Table 1). Patients with a false-positive anti-cN1A antibody had diagnoses of: primary Raynaud’s (n = 5); undifferentiated CTD (n = 3); systemic sclerosis (n = 2); non-sIBM myositis (n = 2). Conclusion Anti-cN1A detected using the EUROLINE 16 Antigen assay has high specificity but lacks sensitivity for sIBM, consistent with previous literature. These findings suggest that this assay performs similarly to other cN1A detection methodologies and has utility in confirming the diagnosis of sIBM where there is clinical suspicion. Further real-world analysis of antibody data in larger cohorts is required to clarify the role of serological testing in sIBM diagnostic criteria, to improve diagnostic delays and misclassifications. Disclosure M. Al-Attar: None. T. Khoo: None. J.B. Lilleker: None. H. Chinoy: None.

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

To investigate the prevalence and characteristics of typical polymyositis (PM) in Chinese patients with idiopathic inflammatory myopathy (IIM). 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. 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. 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.

Quantitative whole-body muscle MRI in idiopathic inflammatory myopathies including polymyositis with mitochondrial pathology: indications for a disease spectrum

ObjectiveInflammatory myopathies (IIM) include dermatomyositis (DM), sporadic inclusion body myositis (sIBM), immune-mediated necrotizing myopathy (IMNM), and overlap myositis (OLM)/antisynthetase syndrome (ASyS). There is also a rare variant termed polymyositis with mitochondrial pathology (PM-Mito), which is considered a sIBM precursor. There is no information regarding muscle MRI for this rare entity. The aim of this study was to compare MRI findings in IIM, including PM-Mito.MethodsThis retrospective analysis included 41 patients (7 PM-Mito, 11 sIBM, 11 PM/ASyS/OLM, 12 IMNM) and 20 healthy controls. Pattern of muscle involvement was assessed by semiquantitative evaluation, while Dixon method was used to quantify muscular fat fraction.ResultsThe sIBM typical pattern affecting the lower extremities was not found in the majority of PM-Mito-patients. Intramuscular edema in sIBM and PM-Mito was limited to the lower extremities, whereas IMNM and PM/ASyS/OLM showed additional edema in the trunk. Quantitative assessment showed increased fat content in sIBM, with an intramuscular proximo-distal gradient. Similar changes were also found in a few PM-Mito- and PM/ASyS/OLM patients. In sIBM and PM-Mito, mean fat fraction of several muscles correlated with clinical involvement.InterpretationAs MRI findings in patients with PM-Mito relevantly differed from sIBM, the attribution of PM-Mito as sIBM precursor should be critically discussed. Some patients in PM/ASyS/OLM and PM-Mito group showed MR-morphologic features predominantly observed in sIBM, indicative of a spectrum from PM/ASyS/OLM toward sIBM. In some IIM subtypes, MRI may serve as a biomarker of disease severity.

Inclusion Body Myositis in Children: Does it Exist?

Context: Sporadic inclusion body myositis (sIBM) is a rare type of juvenile idiopathic inflammatory myopathies (JIIMs). It mainly affects skeletal muscles but can also affect the skin and other organs in the body. Sporadic inclusion body myositis prevalence in children under 18 years old is very rare. Objectives: This review provides an overview of the evidence of sIBM in children, discusses the possible clinical and pathological features, and explores the proposed pathogenesis. Methods: A literature review of over 44 articles in PubMed and other medical libraries, such as Google Scholar and Web of Science, was carried out using terms such as JIIM, IBM, Inflammatory Myopathies in Children, and Inherited IBM. Two documented reports for sIBM were found, and the rest included the disease pathogenesis, prevalence of inherited IBM, and other myopathies in children. Results: This review discussed the prevalence and incidence of JIIM, in particular sIBM in children. While IBM is typically sporadic, there have been rare cases where it is familial and inherited. Genetic susceptibility factors are believed to play a role in sIBM. Most patients with sIBM are over 50 years old and experience significant weakness in the quadriceps; however, patients with inherited IBM (h-IBM) typically present earlier in adulthood with a distinct pattern of weakness. Sporadic inclusion body myositis can be misdiagnosed as other forms of myopathies, such as juvenile dermatomyositis (JDM) or limb-girdle muscular dystrophy (LGMD), during the early stages of the disease. The exact causes of sIBM are still unknown; however, environmental factors, genetic predispositions, and immune dysregulation might contribute to the pathogenesis of the disease. Conclusions: Sporadic inclusion body myositis is a rare form of JIIMs. Its early diagnosis in children can be challenging due to the presence of other coexisting diseases. Discussions have revolved around potential environmental factors, such as viral infections, specific myositis-specific antibodies (MSAs), such as anti-Ro52, and possibly certain human leukocyte antigen (HLA) haplotypes. Given the rarity of reported cases of sIBM in children, it is important to encourage further studies to better understand the underdiagnosed instances of this condition.

Inclusion-body myositis associated with Sjögren's disease: clinical characteristics and comparison with other Sjögren-associated myositis.

To describe the characteristics of patients with Sjögren's disease (SjD) and inclusion-body myositis (IBM), and how they compare to SjD patients with other inflammatory myopathies (IM). Patients were retrospectively recruited from 13 French centers and included if they met the ACR/EULAR criteria for SjD and for IM. They were categorized as SjD-IBM if sub-criteria for IBM were met, or as SjD-other IM if not. SjD-IBM patients (n = 22) were mostly females (86%), with a median [Q1; Q3] age of 54 [38.5; 64] years at SjD diagnosis, and 62 [46.5; 70] years at first IBM symptoms. Although most patients displayed glandular and immunological abnormalities, additional extra-glandular manifestations were uncommon, resulting in moderate disease activity at SjD diagnosis (ESSDAI 5.5 [1; 7.8]). Classic IBM features were frequent, such as progressive symptom onset (59%), asymmetrical (27%) and distal (32%) involvements, dysphagia (41%), low CPK (386.5 [221.8; 670.5] UI/l) and CRP (3.0 [3; 8.5] mg/l) levels. Immunosuppressants were reported as efficient in 55% of cases.Compared with SjD-IBM patients, SjD patients with other IM (n = 50) were significantly younger, displayed more frequent additional extra-glandular disease, higher ESSDAI score (11 [3; 30]), shorter delay between SjD diagnosis and myositis onset (0 [-0.5; 26]), more frequent CPK values over 1000 UI/l (36%), and less frequent classic IBM features. IBM can occur in SjD patients, with muscle features reminiscent of classic sporadic IBM characteristics, but mostly affecting women. In SjD patients with muscle involvement, extra-glandular manifestations, high ESSDAI score, elevated CPK values, and shorter delay after SjD diagnosis plead against IBM.

Sporadic Inclusion Body Myositis at the Crossroads between Muscle Degeneration, Inflammation, and Aging.

Sporadic inclusion body myositis (sIBM) is the most common muscle disease of older people and is clinically characterized by slowly progressive asymmetrical muscle weakness, predominantly affecting the quadriceps, deep finger flexors, and foot extensors. At present, there are no enduring treatments for this relentless disease that eventually leads to severe disability and wheelchair dependency. Although sIBM is considered a rare muscle disorder, its prevalence is certainly higher as the disease is often undiagnosed or misdiagnosed. The histopathological phenotype of sIBM muscle biopsy includes muscle fiber degeneration and endomysial lymphocytic infiltrates that mainly consist of cytotoxic CD8+ T cells surrounding nonnecrotic muscle fibers expressing MHCI. Muscle fiber degeneration is characterized by vacuolization and the accumulation of congophilic misfolded multi-protein aggregates, mainly in their non-vacuolated cytoplasm. Many players have been identified in sIBM pathogenesis, including environmental factors, autoimmunity, abnormalities of protein transcription and processing, the accumulation of several toxic proteins, the impairment of autophagy and the ubiquitin-proteasome system, oxidative and nitrative stress, endoplasmic reticulum stress, myonuclear degeneration, and mitochondrial dysfunction. Aging has also been proposed as a contributor to the disease. However, the interplay between these processes and the primary event that leads to the coexistence of autoimmune and degenerative changes is still under debate. Here, we outline our current understanding of disease pathogenesis, focusing on degenerative mechanisms, and discuss the possible involvement of aging.

Sporadic inclusion body myositis-derived myotube culture revealed muscle cell-autonomous expression profiles.

Sporadic inclusion body myositis (sIBM) is a muscle disease in older people and is characterized by inflammatory cell invasion into intact muscle fibers and rimmed vacuoles. The pathomechanism of sIBM is not fully elucidated yet, and controversy exists as to whether sIBM is a primary autoimmune disease or a degenerative muscle disease with secondary inflammation. Previously, we established a method of collecting CD56-positive myoblasts from human skeletal muscle biopsy samples. We hypothesized that the myoblasts derived from these patients are useful to see the cell-autonomous pathomechanism of sIBM. With these resources, myoblasts were differentiated into myotubes, and the expression profiles of cell-autonomous pathology of sIBM were analyzed. Myoblasts from three sIBM cases and six controls were differentiated into myotubes. In the RNA-sequencing analysis of these "myotube" samples, 104 differentially expressed genes (DEGs) were found to be significantly upregulated by more than twofold in sIBM, and 13 DEGs were downregulated by less than twofold. For muscle biopsy samples, a comparative analysis was conducted to determine the extent to which "biopsy" and "myotube" samples differed. Fifty-three DEGs were extracted of which 32 (60%) had opposite directions of expression change (e.g., increased in biopsy vs decreased in myotube). Apolipoprotein E (apoE) and transmembrane protein 8C (TMEM8C or MYMK) were commonly upregulated in muscle biopsies and myotubes from sIBM. ApoE and myogenin protein levels were upregulated in sIBM. Given that enrichment analysis also captured changes in muscle contraction and development, the triggering of muscle atrophy signaling and abnormal muscle differentiation via MYMK or myogenin may be involved in the pathogenesis of sIBM. The presence of DEGs in sIBM suggests that the myotubes formed from sIBM-derived myoblasts revealed the existence of muscle cell-autonomous degeneration in sIBM. The catalog of DEGs will be an important resource for future studies on the pathogenesis of sIBM focusing on primary muscle degeneration.

Imaging swallowing function and the mechanisms driving dysphagia in inclusion body myositis.

Sporadic inclusion body myositis (IBM) is a progressive condition which commonly affects patients aged above 40. IBM does not respond to immunosuppression and no proven treatments are available. Up to 80% of patients develop some degree of swallowing impairment during the disease course. Dysphagia is a source of marked morbidity in IBM and predisposes patients to life-threatening complications such as aspiration pneumonia. The pathophysiology behind dysphagia in IBM is not fully understood. Evidence from imaging demonstrates that impaired swallowing is predominantly underpinned by oropharyngeal deficits. Changes in cricopharyngeal physiology is thought to be an important factor influencing dysphagia in IBM. However, it is unclear whether this is secondary to structural changes within the cricopharyngeus itself or driven by impairment of the muscles promoting pharyngeal clearance. The approach to dysphagia in IBM patients is limited by a lack of validated instruments to reliably assess swallowing function and an absence of effective therapeutic interventions derived from controlled trials targeting dysphagia. Imaging modalities such as the video fluoroscopic swallowing study (VFSS) are commonly used to evaluate dysphagia in IBM. Whilst VFSS is a commonly used technique in clinical practice; cumulative radiation exposure with repeated testing can be a limitation. Alternative imaging techniques could be developed further as outcome measures for assessing swallowing.In this review, we provide an overview of imaging techniques used to assess swallowing and the insight provided from such investigations into the mechanisms behind dysphagia in IBM. We suggest future directions for evaluation and outcome measurement of dysphagia in this population.

Pathogenic role of anti-cN1A autoantibodies in sporadic inclusion body myositis

BackgroundSporadic inclusion body myositis (sIBM) is an intractable muscle disease that frequently affects elderly people. Autoantibodies recognising cytosolic 5’-nucleotidase 1A (cN1A) were found in the sera of patients with sIBM....

Tendon Transfers to Improve Grip and Pinch in Patients with Sporadic Inclusion Body Myositis.

Sporadic inclusion body myositis (sIBM) is a rare and slowly progressive skeletal muscle disease that can cause hand dysfunction, which is a major source of disability. Tendon transfers have been reliably used to improve function in other neuromuscular settings. Given that sIBM patients often present with flexion impairments and mostly functioning extensors, we investigated the potential opportunity for tendon transfer surgery to improve hand dysfunction in sIBM patients. We conducted a scoping review for studies of sIBM and tendon transfers, extracted descriptions of hand function and surgical technique, and recorded results in terms of hand function. We also conducted an institutional review board-approved survey with 470 participants to determine baseline patient-reported function and to determine participant perceptions and expectations for tendon transfer surgery to improve hand function in sIBM. We identified three published case reports on tendon transfers in sIBM patients with subjectively improved grip and pinch strength, but standardized measures of hand function or quality-of-life were not reported. Within the surveyed cohort, half of participants reported that they would consider surgery, yet only 8% had been referred to a hand surgeon. Fifty four percent of participants reported that they would consider surgery if there would be 1-2 years of benefit after surgery. All participants who would consider surgery also had significant upper extremity disability. Tendon transfer surgery has the potential to improve quality-of-life for sIBM patients, and there is significant patient interest in this approach. To objectively assess its efficacy, we propose conducting a surgical trial.

Paraneoplastic dermatomyositis associated with urothelial cancer: report of a case and systematic review of the literature.

The idiopathic inflammatory myopathies (IIM) are a collection of autoimmune diseases that have a substantial impact on the entire body and include conditions such as dermatomyositis (DM), polymyositis (PM), sporadic inclusion body myositis, and immune-mediated necrotizing myopathy. These disorders are characterized by symptoms such as muscular weakness, pain, and dermal rash. This systematic review is intended to explore the potential link between bladder cancer and DM/PM. We performed a comprehensive systematic search on PubMed and Scopus until August 2022 to identify relevant research studies. The studies that met our inclusion criteria focused on patients with urinary bladder cancer and dermatomyositis, and/or polymyositis. The patients' median age was 65.5 years (47-79), with the majority being male (15, 39.47%). Bladder cancer manifested before PM/DM in 5 (13.15%) patients, while in the majority of cases occurred after the cancer diagnosis. The stage of cancer at the time of the initial PM/DM diagnosis were mostly locally (11/20, 50%).During the first presentation, the patients had a median creatine kinase level of 2227 U/L, ranging between 44 and 10471. In one case, anti-TIF-1γ antibodies were found to be present. Among the cases with reported medical history (20/38), treatment immediately improved DM symptoms in 16 patients(53.8%) and in 3 patients(15%), symptoms of DM resurfaced during the period after the operation. Death was reported in 14 (36.8%) patients. In conclusion, our study provides knowledge and understanding for identifying specific risk factors in patients with the coexistence of bladder cancer and DM/PM and their management. During the initial and follow-up screening, age, gender, and the clinicopathological subgroup of myositis should be considered to ensure proper management of the condition.

P340 The MikroIBioM study - Comparison of gut microbiome of sporadic Inclusion Body Myositis (sIBM) patients and unaffected spouses

P340 The MikroIBioM study - Comparison of gut microbiome of sporadic Inclusion Body Myositis (sIBM) patients and unaffected spouses

Retrospective Study Shows That Serum Levels of Chemokine CXCL10 and Cytokine GDF15 Support a Diagnosis of Sporadic Inclusion Body Myositis and Immune-Mediated Necrotizing Myopathy.

The implementation of novel blood-based biomarkers is desired to reduce the diagnostic delay and burden for myositis patients. In this retrospective study, the potential of C-X-C motif chemokine ligand 10 (CXCL10) and growth differentiation factor 15 (GDF15) was explored in an established patient cohort diagnosed with immune-mediated necrotizing myopathy (IMNM; n = 21), sporadic inclusion body myositis (IBM; n = 18), overlap myositis (OM; n = 3), dermatomyositis (DM; n = 2), and anti-synthetase syndrome (ASS; n = 1), comparing these results with healthy controls (n = 10) and patients with a hereditary neuromuscular disorder (n = 14). CXCL10 and GDF15 were quantified in sera with enzyme-linked immunosorbent assays and immunolocalized in skeletal muscle tissue. In myositis patients, serum CXCL10 levels were significantly increased 9.6-fold compared to healthy controls and 4.2-fold compared to disease controls. Mean levels of CXCL10 were 929 ± 658 pg/mL of serum in IBM and 425 ± 324 pg/mL of serum in IMNM. With the threshold set to 180 pg/mL of CXCL10, myositis patients could be differentiated from healthy and disease controls with a sensitivity of 0.80 and a specificity of 0.71. Incorporating a threshold of 300 pg/mL for GDF15 reduced false negatives to two IMNM patients only. Subsets of muscle-infiltrating immune cells expressed CXCL10, and serum levels correlated with muscle inflammation grade. We propose adding circulating CXCL10 and GDF15 to the blood-based diagnostic toolkit for myositis as a valuable patient-friendly approach.