Nontraumatic Myositis Ossificans After Spontaneous Subarachnoid Hemorrhage: A Case Report.

Myositis ossificans is uncommon in patients with nontraumatic brain injuries. This report presents a challenging case in which myositis ossificans was diagnosed and treated by medical management in a patient who was unable to complain of any symptoms due to akinetic mutism that occurred after nontraumatic subarachnoid hemorrhage. The patient had intermittent high-grade fever, and laboratory tests showed elevated C-reactive protein and D-dimer levels without clinical signs of infection two months after subarachnoid hemorrhage. Lower-extremity venography using computed tomography was performed to rule out deep venous thrombosis. There was no thrombus, but right vastus medialis muscle showed inflammatory change with faint multilayered curvilinear hyperdense rims. The administration of indomethacin helped prevent abnormal bone formation. For the early detection of myositis ossificans, careful observation of clinical presentation and a high index of clinical suspicion is necessary in brain-injured patients. Further, elevated serum inflammatory markers accompanied by elevated alkaline phosphatase can be a critical clue. Early computed tomography helps identify early 'string sign' prior to characteristic ossification. Our report highlights that the myositis ossificans is remediable by early detection and appropriate nonsurgical management.

Identification of connective tissue disease autoantibodies and a novel autoantibody anti-annexin A11 in patients with "idiopathic" interstitial lung disease.

BACKGROUND: Autoantibodies are a hallmark feature of Connective Tissue Diseases (CTD). Their presence in patients with idiopathic interstitial lung disease (ILD) may suggest covert CTD. We aimed to determine the prevalence of CTD autoantibodies in patients diagnosed with idiopathic ILD. METHODS: 499 patient sera were analysed: 251 idiopathic pulmonary fibrosis (IPF), 206 idiopathic non-specific interstitial pneumonia (iNSIP) and 42 cryptogenic organising pneumonia (COP). Autoantibody status was determined by immunoprecipitation. RESULTS: 2.4% of IPF sera had a CTD-autoantibody compared to 10.2% of iNSIP and 7.3% of COP. 45% of autoantibodies were anti-synthetases. A novel autoantibody targeting an unknown 56 kDa protein was found in seven IPF patients (2.8%) and two NSIP (1%) patients. This was characterised as anti-annexin A11. CONCLUSION: Specific guidance on autoantibody testing and interpretation in patients with ILD could improve diagnostic accuracy. Further work is required to determine the clinical significance of anti-annexin A11.

Immune-Mediated Necrotizing Myopathies: Current Landscape.

PURPOSE OF REVIEW: Immune-mediated necrotizing myopathy (IMNM), characterized by acute or subacute onset, severe weakness, and elevated creatine kinase levels, poses diagnostic and therapeutic challenges. This article provides a succinct overview of IMNM, including clinical features, diagnostic strategies, and treatment approaches. RECENT FINDINGS: Recent insights highlight the different clinical presentations and therapeutic options of IMNM stratified by autoantibody positivity and type. Additionally, recent findings call into question the reported link between statin use and IMNM. This review synthesizes current knowledge on IMNM, emphasizing its distinct clinical features and challenging management. The evolving understanding of IMNM underscores the need for a comprehensive diagnostic approach that utilizes a growing range of modalities. Early and aggressive immunomodulatory therapy remains pivotal. Ongoing research aims to refine diagnostic tools and therapeutic interventions for this challenging muscle disorder, underscoring the importance of advancing our understanding to enhance patient outcomes.

Unprecedented complexity of six coexisting autoimmune diseases: A case report.

INTRODUCTION: Autoimmune disorders often exhibit interconnectedness, although encountering multiple autoimmune conditions in a single patient is uncommon. Multiple autoimmune syndrome is characterized by the presence of at least three distinct autoimmune diseases in an individual. This report outlines the case of a middle-aged woman diagnosed with autoimmune thyroiditis, Sjögren's syndrome, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, and antisynthetase syndrome. Additionally, it includes a literature review encompassing multiple autoimmune syndromes involving five or more autoimmune diseases. OBSERVATION: A 57-year-old woman, with no previous medical history, presented with fever, extensive muscle weakness, progressive exertional dyspnea, inflammatory polyarthralgia, dysphagia, and dry mouth. Clinical examination revealed muscular deficit in the scapular and pelvic girdles, distal muscular deficit, synovitis in the wrists, and features indicative of "mechanic's hand". Laboratory examinations showed cytolysis, cholestasis, elevated muscle enzymes, hypergammaglobulinemia and elevated thyroid stimulating hormone. Immunoassays showed positive results for antinuclear antibodies, anti-histidyl-t-RNA synthetase, anti-Sjögren's-syndrome-related antigen A, anti-ribonucleic-acid-polymerase-III-RP155, anti-fibrillarin, anti-mitochondrial, anti-liver/kidney microsomal type 1, anti-glycoprotein 210, and anti-thyroid peroxidase antibodies. Further investigations led to the diagnosis of a multiple autoimmune syndrome involving autoimmune thyroiditis, Sjögren's syndrome, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, and antisynthetase syndrome. The patient received treatment with intravenous immunoglobulins, corticosteroids, azathioprine, and ursodeoxycholic acid, which resulted in favorable clinical and biological outcomes. CONCLUSION: This patient presented with six concurrent distinct autoimmune disorders, categorizing this case as a type two multiple autoimmune syndrome. The identification of antisynthetase syndrome notably distinguishes this case.

Effectiveness and safety of mycophenolate mofetil and rituximab combination therapy for immune idiopathic myopathies.

INTRODUCTION: Idiopathic inflammatory myopathies (IIM) represent a rare and heterogenous group diseases, and their treatment is not fully defined yet. According to previous small case series, the combination of mycophenolate mofetil (MMF) and rituximab (RTX) may be effective in controlling difficult-to-treat patients. Our aim was to further explore the efficacy and safety of this combined approach in patients with IIM. METHODS: Patients with IIM treated with the RTX/MMF combination in our Center were retrospectively identified. After the start of combination therapy, the efficacy was evaluated at 12 months (T12) according the 2016 ACR/EULAR response criteria for IIM. Cardiac imaging and pulmonary function tests were used to monitor disease activity in patients with myocarditis and interstitial lung disease, respectively. Adverse events were recorded over the follow-up period. RESULTS: Among the 20 patients (median age 61 years; 70% female) included in the study, anti-synthetase syndrome was the most prevalent IIM subgroup (60%). At treatment start, muscle, heart, and lung were the most commonly actively affected organs. After 12 months, a moderate or major response was observed in all patients, and creatine kinase was significantly decreased (p-value = 0.012). Cardiac imaging and enzymes monitoring showed a reduction of heart inflammation, while pulmonary function tests improved in patients with lung involvement. No severe side effects were observed. CONCLUSION: Our data show that combination of RTX and MMF is effective and safe in patients with severe and refractory IIM. Therefore, this combined treatment might represent a feasible approach for difficult-to-treat IIM cases.

Interpreting a Delayed Workup of Idiopathic Inflammatory Myopathy.

Idiopathic inflammatory myopathies are a widely heterogeneous group of muscle diseases and encompass multiple clinicopathologic entities. Our case presentation describes a 70-year-old male who presented with progressively worsening dyspnea, along with worsening proximal muscle weakness in the bilateral lower extremities. Extensive clinical evaluation revealed a creatine kinase level of 105 IU/L, severe and chronic widespread myopathy seen on electromyography (EMG), and asymmetric but widespread muscle atrophy with fibro-fatty replacement seen on ultrasonography. Muscle biopsy specimen from the left deltoid was suboptimal but demonstrated characteristics that could be consistent with several clinicopathologic diagnoses, including sporadic inclusion body myositis (sIBM), immune-mediated necrotizing myositis (IMNM), antisynthetase syndrome (AS), and direct toxin-induced myopathy. Electron microscopy revealed tubulofilamentous inclusion associated with autophagic debris, finally rendering an accurate diagnosis. This case summary highlights the testing workflow required to diagnose a patient with an inflammatory myopathy and outlines the difficulty in establishing a diagnosis when the workup for an inflammatory myopathy is delayed and the muscle biopsy is suboptimal.

Evaluation of Neuromuscular Diseases and Complaints by Quantitative Muscle MRI.

Background: Quantitative muscle MRI (qMRI) is a promising tool for evaluating and monitoring neuromuscular disorders (NMD). However, the application of different imaging protocols and processing pipelines restricts comparison between patient cohorts and disorders. In this qMRI study, we aim to compare dystrophic (limb-girdle muscular dystrophy), inflammatory (inclusion body myositis), and metabolic myopathy (Pompe disease) as well as patients with post-COVID-19 conditions suffering from myalgia to healthy controls. Methods: Ten subjects of each group underwent a 3T lower extremity muscle MRI, including a multi-echo, gradient-echo, Dixon-based sequence, a multi-echo, spin-echo (MESE) T2 mapping sequence, and a spin-echo EPI diffusion-weighted sequence. Furthermore, the following clinical assessments were performed: Quick Motor Function Measure, patient questionnaires for daily life activities, and 6-min walking distance. Results: Different involvement patterns of conspicuous qMRI parameters for different NMDs were observed. qMRI metrics correlated significantly with clinical assessments. Conclusions: qMRI metrics are suitable for evaluating patients with NMD since they show differences in muscular involvement in different NMDs and correlate with clinical assessments. Still, standardisation of acquisition and processing is needed for broad clinical use.

[Expert recommendations for magnetic resonance imaging of muscle disorders]. / Expertenempfehlung zur Magnetresonanztomographie bei Muskelerkrankungen.

BACKGROUND: Magnetic resonance (MRI) imaging of the skeletal muscles (muscle MRI for short) is increasingly being used in clinical routine for diagnosis and longitudinal assessment of muscle disorders. However, cross-centre standards for measurement protocol and radiological assessment are still lacking. OBJECTIVES: The aim of this expert recommendation is to present standards for the application and interpretation of muscle MRI in hereditary and inflammatory muscle disorders. METHODS: This work was developed in collaboration between neurologists, neuroradiologists, radiologists, neuropaediatricians, neuroscientists and MR physicists from different university hospitals in Germany. The recommendations are based on expert knowledge and a focused literature search. RESULTS: The indications for muscle MRI are explained, including the detection and monitoring of structural tissue changes and oedema in the muscle, as well as the identification of a suitable biopsy site. Recommendations for the examination procedure and selection of appropriate MRI sequences are given. Finally, steps for a structured radiological assessment are presented. CONCLUSIONS: The present work provides concrete recommendations for the indication, implementation and interpretation of muscle MRI in muscle disorders. Furthermore, it provides a possible basis for the standardisation of the measurement protocols at all clinical centres in Germany.

Association between anti-PL7 antibodies and increased fibrotic component in patients with antisynthetase syndrome and interstitial lung disease: a cross-sectional study.

OBJECTIVE: To evaluate whether anti-PL7 and anti-PL12 autoantibodies are associated with a greater extent of the fibrotic component of ILD in ASSD patients. METHODS: Patients with ILD-ASSD who were positive for one of the following autoantibodies: anti-Jo1, anti-PL7, anti-PL12, and anti-EJ were included. Clinical manifestations, CPK levels, pulmonary function tests, and HCRT assessments were prospectively collected according to the Goh index. The fibrotic, inflammatory, and overall extension of the Goh index and DLCO were assessed by multiple linear analyses and compared between ASSD antibody subgroups. RESULTS: Sixty-six patients were included; 17 were positive for anti-Jo1 (26%), 17 for anti-PL7 (26%), 20 for anti-PL12 (30%), and 9 (14%) for anti-EJ. Patients with anti-PL7 and anti-PL12 had a more extensive fibrotic component than anti-Jo1. Anti-PL7 patients had a 7.9% increase in the fibrotic extension (cß = 7.9; 95% CI 1.863, 13.918), and the strength of the association was not modified after controlling for sex, age, and time of disease evolution (aß = 7.9; 95% CI 0.677, 15.076) and also was associated with an increase in ILD severity after adjusting for the same variables, denoted by a lower DLCO (aß = - 4.47; 95% CI - 8.919 to - 0.015). CONCLUSIONS: Anti-PL7-positive ASSD patients had more extensive fibrosis and severe ILD than the anti-Jo1 subgroup. This information is clinically useful and has significant implications for managing these patients, suggesting the need for early consideration of concurrent immunosuppressive and antifibrotic therapy.

Anti-U1RNP antibodies are associated with a distinct clinical phenotype and a worse survival in patients with systemic sclerosis.

OBJECTIVES: To clarify the impact of anti-U1RNP antibodies on the clinical features and prognosis of patients with SSc. METHODS: We conducted a monocentric case-control, retrospective, longitudinal study. For each patient with SSc and anti-U1RNP antibodies (SSc-RNP+), one patient with mixed connective tissue disease (MCTD) and 2 SSc patients without anti-U1RNP antibodies (SSc-RNP-) were matched for age, sex, and date of inclusion. RESULTS: Sixty-four SSc-RNP+ patients were compared to 128 SSc-RNP- and 64 MCTD patients. Compared to SSc-RNP-, SSc-RNP+ patients were more often of Afro-Caribbean origin (31.3% vs. 11%, p < 0.01), and more often had an overlap syndrome than SSc-RNP- patients (53.1 % vs. 22.7%, p < 0.0001), overlapping with Sjögren's syndrome (n = 23, 35.9%) and/or systemic lupus erythematosus (n = 19, 29.7%). SSc-RNP+ patients were distinctly different from MCTD patients but less often had joint involvement (p < 0.01). SSc-RNP+ patients more frequently developed interstitial lung disease (ILD) (73.4% vs. 55.5% vs. 31.3%, p < 0.05), pulmonary fibrosis (PF) (60.9% vs. 37.5% vs. 10.9%, p < 0.0001), SSc associated myopathy (29.7% vs. 6.3% vs. 7.8%, p < 0.0001), and kidney involvement (10.9% vs. 2.3% vs. 1.6%, p < 0.05). Over a 200-month follow-up period, SSc-RNP+ patients had worse overall survival (p < 0.05), worse survival without PF occurrence (p < 0.01), ILD or PF progression (p < 0.01 and p < 0.0001). CONCLUSIONS: In SSc patients, anti-U1RNP antibodies are associated with a higher incidence of overlap syndrome, a distinct clinical phenotype, and poorer survival compared to SSc-RNP- and MCTD patients. Our study suggests that SSc-RNP+ patients should be separated from MCTD patients and may constitute an enriched population for progressive lung disease.

Clinical Features and Outcomes of Patients with Idiopathic Inflammatory Myositis-Associated Interstitial Lung Disease in Rural Appalachia: A Cross-Sectional Study.

BACKGROUND: Idiopathic inflammatory myopathies (IIMs) are a group of autoimmune disorders often complicated by interstitial lung disease (ILD). The clinical characteristics and outcomes of IIM-associated ILD have been reported variably, but the literature on rural populations is scarce. METHODS: A retrospective cross-sectional study was conducted at a rural tertiary academic medical center. Twenty-nine patients met the final inclusion criteria. The primary outcome was to assess the disease state and immunological and radiographic features of IIM-associated ILD. Secondary outcomes included disease progression, ILD exacerbation, mortality rate, and factors associated with poor outcome. RESULTS: Dermatomyositis (n = 15, 51.72%) followed by polymyositis (n = 8, 27.58%) were predominant myopathies. The most common autoantibodies were anti-Jo1 antibodies (n = 11, 37.93%). Indeterminate usual interstitial pneumonitis (41.30%, n = 12) was the most common radiographic pattern followed by non-specific interstitial pneumonia (n = 5, 17.24%). ILD exacerbation (n = 14, 66.66%) and mortality rate (n = 6, 20.69%) were high. Albumin levels were significantly lower in patients who died. CONCLUSIONS: The clinical characteristics of patients with IIM-associated ILD in rural Appalachia exhibit notable distinctions, and outcomes are worse compared to other populations. Larger studies are needed to investigate other prognostics factors and longitudinal trends of clinical characteristics and outcomes of IIM-associated ILD in rural populations.

Myositis-associated antibodies predict the severity of lung involvement in adult patients with inflammatory myositis - a cohort study of 70 adult patients with myositis in a single center.

Introduction: Idiopathic inflammatory myopathies (IIMs) encompass a diverse group of diseases characterized by considerable variability in clinical manifestations, antibody profiles, and responsiveness to immunosuppressive therapies. This study aimed to investigate the association between organ involvement and distinct myositis autoantibodies in individuals with IIM in a single-center cohort. Methods: Patients with ICD diagnoses M33.1, M33.2, M33.9, or M609 who (1) had been tested with Euroline blot assay for myositis autoantibodies and (2) met the classification criteria of definite/probable polymyositis (PM) or dermatomyositis (DM), anti-synthetase syndrome (ASS), or inclusion body myositis (IBM) were included. Medical journals were retrospectively examined with respect to clinical disease features. Results: Seventy patients (median age 58 years; 66% females) were included and represented the following diagnosis: PM (n = 23), DM (n = 21), ASS (n = 23), and IBM (n = 3). Most of the patients (87%) presented a muscle biopsy indicative of myositis. The presence of autoantibodies was as follows: myositis-specific antibodies, MSA (n = 53), myositis-associated antibodies, MAA (n = 33), both MSA + MAA (n = 24), MSA only (n = 29), MAA only (n = 9), no MSA, or MAA (n = 8). Anti-Jo-1 was the most common MSA (19%), whereas the most common MAA was anti-Ro/SSA52 (31%). We observed a significant association between antibody patterns and lung disease. In our cohort, 47% of the patients in the whole study group, 86% of patients with anti-SSA52, and 100% with anti-Jo-1 had pulmonary involvement. Patients with both MSA and MAA had a higher incidence of lung disease and decreased CO-diffusion capacity. This was especially prominent in anti-Ro/SSA52-positive patients. Interestingly, none of the patients suffered from lung disease if only antibodies against Mi-2α, Mi-2ß, NXP2, HMGCR, and TIF1γ were present or no MSA/MAA were detected. Discussion: The simultaneous presence of both MAA and MSA indicates an increased risk of lung involvement in patients with inflammatory myopathies. The presence of any MAA, and especially anti-Ro/SSA52, is associated with more severe pulmonary disease. Our data suggest that MAA antibodies might be relevant markers for early detection and treatment of lung involvement in IIM.

Management of Select Adverse Events Following Delandistrogene Moxeparvovec Gene Therapy for Patients With Duchenne Muscular Dystrophy.

BACKGROUND: Duchenne muscular dystrophy (DMD) is a rare, degenerative, recessive X-linked neuromuscular disease. Mutations in the gene encoding dystrophin lead to the absence of functional dystrophin protein. Individuals living with DMD exhibit progressive muscle weakness resulting in loss of ambulation and limb function, respiratory insufficiency, and cardiomyopathy, with multiorgan involvement. Adeno-associated virus vector-mediated gene therapy designed to enable production of functional dystrophin protein is a new therapeutic strategy. Delandistrogene moxeparvovec (Sarepta Therapeutics, Cambridge, MA) is indicated for treatment of ambulatory pediatric patients aged 4 through 5 years with DMD who have an indicated mutation in the DMD gene. OBJECTIVE: Evidence-based considerations for management of potential adverse events following gene therapy treatment for DMD are lacking in clinical literature. Our goal was to provide interdisciplinary consensus considerations for selected treatment-related adverse events (TRAEs) (vomiting, acute liver injury, myocarditis, and immune-mediated myositis) that may arise following gene therapy dosing with delandistrogene moxeparvovec. METHODS: An interdisciplinary panel of 12 specialists utilized a modified Delphi process to develop consensus considerations for the evaluation and management of TRAEs reported in delandistrogene moxeparvovec clinical studies. Panelists completed 2 Questionnaires prior to gathering for an in-person discussion. Consensus was defined as a majority (≥58% ; 7/12) of panelists either agreeing or disagreeing. RESULTS: Panelists agreed that the choice of baseline assessments should be informed by individual clinical indications, the treating provider's judgment, and prescribing information. Corticosteroid dosing for treatment of TRAEs should be optimized by considering individual risk versus benefit for each indication. In all cases involving patients with a confirmed TRAE, consultations with appropriate specialists were suggested. CONCLUSIONS: The Delphi Panel established consensus considerations for the evaluation and management of potential TRAEs for patients receiving delandistrogene moxeparvovec, including vomiting, acute liver injury, myocarditis, and immune-mediated myositis.

Effect of sirolimus on muscle in inclusion body myositis observed with magnetic resonance imaging and spectroscopy.

BACKGROUND: Finding sensitive clinical outcome measures has become crucial in natural history studies and therapeutic trials of neuromuscular disorders. Here, we focus on 1-year longitudinal data from quantitative magnetic resonance imaging (MRI) and phosphorus magnetic resonance spectroscopy (31P MRS) in a placebo-controlled study of sirolimus for inclusion body myositis (IBM), also examining their links to functional, strength, and clinical parameters in lower limb muscles. METHODS: Quantitative MRI and 31P MRS data were collected at 3 T from a single site, involving 44 patients (22 on placebo, 22 on sirolimus) at baseline and year-1, and 21 healthy controls. Assessments included fat fraction (FF), contractile cross-sectional area (cCSA), and water T2 in global leg and thigh segments, muscle groups, individual muscles, as well as 31P MRS indices in quadriceps or triceps surae. Analyses covered patient-control comparisons, annual change assessments via standard t-tests and linear mixed models, calculation of standardized response means (SRM), and exploration of correlations between MRI, 31P MRS, functional, strength, and clinical parameters. RESULTS: The quadriceps and gastrocnemius medialis muscles had the highest FF values, displaying notable heterogeneity and asymmetry, particularly in the quadriceps. In the placebo group, the median 1-year FF increase in the quadriceps was 3.2% (P < 0.001), whereas in the sirolimus group, it was 0.7% (P = 0.033). Both groups experienced a significant decrease in cCSA in the quadriceps after 1 year (P < 0.001), with median changes of 12.6% for the placebo group and 5.5% for the sirolimus group. Differences in FF and cCSA changes between the two groups were significant (P < 0.001). SRM values for FF and cCSA were 1.3 and 1.4 in the placebo group and 0.5 and 0.8 in the sirolimus group, respectively. Water T2 values were highest in the quadriceps muscles of both groups, significantly exceeding control values in both groups (P < 0.001) and were higher in the placebo group than in the sirolimus group. After treatment, water T2 increased significantly only in the sirolimus group's quadriceps (P < 0.01). Multiple 31P MRS indices were abnormal in patients compared to controls and remained unchanged after treatment. Significant correlations were identified between baseline water T2 and FF at baseline and the change in FF (P < 0.001). Additionally, significant correlations were observed between FF, cCSA, water T2, and functional and strength outcome measures. CONCLUSIONS: This study has demonstrated that quantitative MRI/31P MRS can discern measurable differences between placebo and sirolimus-treated IBM patients, offering promise for future therapeutic trials in idiopathic inflammatory myopathies such as IBM.

Viral Myositis in an Eight-Year-Old.

Benign acute childhood myositis (BACM) is a pediatric syndrome characterized by mild self-limiting sudden onset of muscle pain during or following recovery from a viral illness. The case discussed in this report is of an eight-year-old female diagnosed with the common cold after presenting to her primary care physician. Five days later, the patient presented to the emergency department with lower extremity pain. The patient was sent home with supportive care and mild analgesics. Twelve hours later, the patient was seen again in the emergency department with severe bilateral lower extremities pain and difficulty walking. BACM most commonly affects school-age children and is usually caused by influenza A and B. The main goal of this case report is to help primary care and emergency medicine physicians diagnose benign acute childhood myositis as early as possible and treat the condition appropriately.

Diagnosing and characterizing inflammatory myopathies at an Australian tertiary public hospital: Resource utilization and direct healthcare costs.

AIM: To determine the direct health service costs and resource utilization associated with diagnosing and characterizing idiopathic inflammatory myopathies (IIMs), and to assess for limitations and diagnostic delay in current practice. METHODS: A retrospective, single-center cohort analysis of all patients diagnosed with IIMs between January 2012 and December 2021 in a large tertiary public hospital was conducted. Demographics, resource utilization and costs associated with diagnosing IIM and characterizing disease manifestations were identified using the hospital's electronic medical record and Health Intelligence Unit, and the Medicare Benefits Schedule. RESULTS: Thirty-eight IIM patients were identified. IIM subtypes included dermatomyositis (34.2%), inclusion body myositis (18.4%), immune-mediated necrotizing myopathy (18.4%), polymyositis (15.8%), and anti-synthetase syndrome (13.2%). The median time from symptom onset to diagnosis was 212 days (IQR: 118-722), while the median time from hospital presentation to diagnosis was 30 days (8-120). Seventy-six percent of patients required emergent hospitalization during their diagnosis, with a median length of stay of 8 days (4-15). The average total cost of diagnosing IIM was $15 618 AUD (STD: 11331) per patient. Fifty percent of patients underwent both MRI and EMG to identify affected muscles, 10% underwent both pan-CT and PET-CT for malignancy detection, and 5% underwent both open surgical and percutaneous muscle biopsies. Autoimmune serology was unnecessarily repeated in 37% of patients. CONCLUSION: The diagnosis of IIMs requires substantial and costly resource use; however, our study has identified potential limitations in current practice and highlighted the need for streamlined diagnostic algorithms to improve patient outcomes and reduce healthcare-related economic burden.

Immune checkpoint inhibitor related myositis: an observational, retrospective, pharmacovigilance study.

BACKGROUND: Immune checkpoint inhibitors (ICIs) show promise in cancer treatment, but recent cases highlight myositis as a serious complication. RESEARCH DESIGN AND METHODS: We did a retrospective study on drug safety using FAERS data up to Q3 2022, focusing on immune checkpoint inhibitors (ICIs) and myositis. We used IC and ROR to assess the association. Logistic regression in R 3.2.5 helped identify factors linked to fatal outcomes. RESULTS: We identified 558 cases of ICIs-associated myositis. Our study found a significant link between ICIs and myositis (ROR 15.54 [14.23-16.96], IC 3.79 [3.66-3.92], see Figure 1). Notably, myositis was more common in patients on ICI combination therapy compared to monotherapy (ROR 1.72 [1.39-2.11], IC 0.63 [0.30-0.93]). Age increased the risk of ICI-associated myositis and was also a factor in fatality (p = 0.011). Common accompanying adverse events included myocarditis (21.33%), severe myasthenia gravis (16.49%), and malignant neoplasm progression (8.06%). Fatal cases were more common when myositis was accompanied by myocarditis, severe myasthenia gravis, or malignant neoplasm progression. CONCLUSIONS: Clinicians must note the risk of ICI-associated myositis, especially dangerous in older patients or when combined with other issues like myocarditis or severe myasthenia gravis.