[Current and Future Status of Muscle Pathology: The Position of Muscle Pathology Diagnosis in the Future].

Many muscle disease names are mostly based on muscle pathology findings. Naturally, muscle pathology is important in the diagnosis of muscle diseases. Moreover, in recent years, extensive genetic analysis and autoantibody testing for myositis have been applied clinically, although muscle biopsies are less performed. However, muscle pathology should be proactively considered when a single gene presents multiple phenotypes, when variants of unknown pathological significance are detected, or in cases of autoimmune myositis that may be misdiagnosed as muscular dystrophy.

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.

Revealing myopathy spectrum: integrating transcriptional and clinical features of human skeletal muscles with varying health conditions.

Myopathy refers to a large group of heterogeneous, rare muscle diseases. Bulk RNA-sequencing has been utilized for the diagnosis and research of these diseases for many years. However, the existing valuable sequencing data often lack integration and clinical interpretation. In this study, we integrated bulk RNA-sequencing data from 1221 human skeletal muscles (292 with myopathies, 929 controls) from both databases and our local samples. By applying a method similar to single-cell analysis, we revealed a general spectrum of muscle diseases, ranging from healthy to mild disease, moderate muscle wasting, and severe muscle disease. This spectrum was further partly validated in three specific myopathies (97 muscles) through clinical features including trinucleotide repeat expansion, magnetic resonance imaging fat fraction, pathology, and clinical severity scores. This spectrum helped us identify 234 genuinely healthy muscles as unprecedented controls, providing a new perspective for deciphering the hallmark genes and pathways among different myopathies. The newly identified featured genes of general myopathy, inclusion body myositis, and titinopathy were highly expressed in our local muscles, as validated by quantitative polymerase chain reaction.

External validation of the 2017 ACR/EULAR classification criteria for inflammatory myopathies in a Mexican cohort: Role of autoantibodies in the diagnosis and classification of patients with inflammatory myopathies / Validación externa de los criterios de clasificación de la ACR/EULAR de 2017 para miopatías inflamatorias en una cohorte mexicana. Papel de los anticuerpos en el diagnóstico y la clasificación de pacientes con miopatías inflamatorias

Objective: This retrospective study aimed to perform the first external validation of the ACR/EULAR classification criteria for inflammatory myopathy (IIM) in a Mexican dynamic cohort where the patients were evaluated with clinical and laboratory values. As secondary objectives, we presented the clinical characteristics of the patients and included antibodies other than anti Jo1 to evaluate their impact on our population. Methodology: This study included 70 patients with IIM and 70 patients with differential diagnoses of IIM, according to the absolute score of the classification criteria. We obtained sensitivity and specificity in the modality without biopsy, and as an exploratory analysis, we added other antibodies from the myositis extended panel. We analyzed the area under the curve (AUC) of three models: score without antibodies, with anti Jo1 and with any antibody. Results: The ACR/EULAR criteria showed increased specificity and at least similar sensitivity to that of the original cohort (85% sensitivity and 92% specificity), with a cohort point of >55%. When we classified patients into definite, probable, possible, and no IIM categories, by adding the extended myopathy panel, 6 of the 10 patients initially classified as “no IIM” changed their classification to “Probable IIM” and 4 to “Definite IIM”; of the 16 patients classified as “probable IIM,” 15 changed their classification to “Definite IIM.” Conclusion: Considering the limitations of this study, we concluded that the 2017 EULAR/ACR criteria for IIM classification are sensitive and specific for classifying patients with IIM in the Mexican population. Additionally, the addition of antibodies other than anti-Jo1 may improve performance in certain populations.(AU)

Objetivo: Este estudio retrospectivo tuvo como objetivo realizar la primera validación externa de los criterios de clasificación ACR/EULAR para miopatía inflamatoria (MII) en una cohorte dinámica de pacientes mexicanos que fueron evaluados en consulta y con muestras de laboratorio. Como objetivos secundarios presentamos las características clínicas de los pacientes e incluimos anticuerpos distintos al anti-Jo1 para evaluar su impacto en nuestra población. Metodología: Este estudio incluyó a 70 pacientes con MII y 70 pacientes con diagnóstico diferencial de MII, según la puntuación absoluta de los criterios de clasificación. Obtuvimos la sensibilidad y la especificidad en la modalidad sin biopsia, y como análisis exploratorio añadimos otros anticuerpos del panel extendido de miositis. Analizamos el área bajo la curva (AUC) de tres modelos: puntuación sin anticuerpos, con anti-Jo1 y con cualquier otro anticuerpo. Resultados: Los criterios ACR/EULAR mostraron una mayor especificidad y una sensibilidad, al menos similar a la de la cohorte original (85% de sensibilidad y 92% de especificidad), con un punto de cohorte de >55%. Cuando clasificamos a los pacientes en las categorías de definitiva, probable, posible y sin MII, al agregar el panel ampliado de miopatía, 6 de los 10 pacientes clasificados inicialmente como «Sin MII» cambiaron su clasificación a «Probable MII» y 4 a «MII Definitiva»; de los 16 pacientes clasificados como «Probable MII», 15 cambiaron su clasificación a «MII Definitiva». Conclusión: Considerando las limitaciones de este estudio, concluimos que los criterios de 2017 de la EULAR/ACR para la clasificación de la MII son sensibles y específicos para clasificar a los pacientes con MII en la población mexicana. Además, la adición de anticuerpos que no sean anti-Jo1 puede mejorar la estadificación en ciertas poblaciones.(AU)

Nephrotic syndrome with rectus sheath hematoma: a case report.

BACKGROUND: Rectus sheath hematoma is a rare presentation often associated with abdominal trauma and anticoagulant therapy. Here, we present a patient with severe rectus sheath hematoma accompanied by nephrotic syndrome who achieved significant clinical improvement without the need for invasive treatment. CASE PRESENTATION: A 72-year-old Japanese woman was referred to our hospital for the treatment of nephrotic syndrome. She was receiving steroid and anticoagulant therapy. Then she had abdominal pain and she was diagnosed with spontaneous rectus sheath hematoma by abdominal computed tomography. She received transfusion and was managed conservatively with bed rest, which led to improvement in abdominal pain. CONCLUSION: Despite the absence of trauma history, rectus sheath hematoma should be considered in patients at risk of vascular failure, including those receiving anticoagulant or steroid therapy, those who are elderly, and those with nephrotic syndrome.

Statin-induced debilitating weakness and myopathy.

A large percentage of the US population is either receiving or should be considered for statin therapy. Whether through primary or secondary prevention for atherosclerotic disease, statins remain one of the mainstay options available to physicians. Myalgias are the most commonly reported side effects, though largely self-limited and subjective in nature. Here, we report a case of drug-related myonecrosis following long-term use of atorvastatin. Prompt recognition of the condition and initiation of treatment is paramount to control the disease's progression. While high-dose steroids are first line, quick escalation to methotrexate, IVIG or rituximab should be considered in refractory cases. This decision is guided by monitoring of serum markers such as CK and transaminases. The goal is quick normalisation of these enzymes, signalling cessation of underlying muscle necrosis. Patients may never regain full function and treatment can last months to years.

Proximal weakness and creatine kinase elevation in systemic sclerosis: Clinical correlates, prognosis and functional implications.

OBJECTIVES: To determine the frequency, clinical correlates and implications of clinical evidence of muscle disease in systemic sclerosis (SSc). METHODS: Australian Scleroderma Cohort Study participants with ≥1 creatine kinase (CK) and proximal power assessment were subdivided according to presence of proximal weakness (PW: proximal muscle power<5/5) and CK elevation(≥140IU/L). Participants were assigned to one of four groups: concurrent PW&CK elevation, PW alone, CK elevation alone or neither. Between-group comparisons were made with chi-squared, ANOVA or Kruskal-Wallis tests. Survival analysis was performed using time-varying-covariate Cox regression modelling. Longitudinal data were modelled using multinomial logistic and linear regression. RESULTS: Of 1786 participants, 4 % had concurrent PW&CK elevation, 15 % PW alone, 24 % CK elevation and 57 % neither. Participants with PW&CK elevation displayed a severe, inflammatory SSc phenotype, with more frequent dcSSc(p < 0.01), tendon friction rubs(p < 0.01), synovitis(p < 0.01) and digital ulceration(p = 0.03). Multimorbidity(p < 0.01) and cardiopulmonary disease, including ischaemic heart disease(p < 0.01) and pulmonary arterial hypertension(p < 0.01), were most common in those with PW, with and without CK elevation. Men with anti-Scl70 positivity most frequently had CK elevation alone, without other significant clinical differences. Multivariable modelling demonstrated 3.6-fold increased mortality in those with PW&CK elevation (95 %CI 1.9-6.6, p < 0.01) and 2.1-fold increased mortality in PW alone (95 %CI 1.4-3.0, p < 0.01) compared to those without PW or CK elevation. CK elevation alone conferred better survival (HR 0.7, 95 %CI 0.4-1.1, p = 0.09) compared to those with no PW or CK elevation. PW regardless of CK elevation was associated with impaired physical function, with reduced six-minute-walk-distance (p < 0.01), higher HAQ-DI scores (p < 0.01) and increased patient-reported dyspnoea (p = 0.04). CONCLUSION: Clinical features of myopathy are highly prevalent in SSc, affecting almost half of our study cohort. Detection of PW and elevated CK alone, even without imaging or histopathological identification of SSc-myopathy, identified important clinical associations and are associated with poorer function and overall prognosis.

[Very-long chain acyl-coA dehydrogenase deficiency: report of a Chinese pedigree and a literature review].

OBJECTIVE: To explore the correlation between clinical classification and genotype and prognosis among Chinese children with Very-long chain acyl-CoA dehydrogenase deficiency (VLCADD). METHODS: A Chinese pedigree affected with VLCADD admitted at the First People's Hospital of Yunnan Province in February 2019 was selected as the study subject. The characteristics of disease onset, diagnosis and treatment and prognosis were retrospectively analyzed. Relevant literature was also systematically searched and reviewed. RESULTS: The proband, a 1-year-old boy, had the clinical manifestations of frequently vomiting, hypoglycemia, abnormal liver function and myocardial enzymes. Tandem mass spectrometry screening showed significantly elevated C14, C14:1, C16:1, C16:2, C18 and C14/C8. Genetic testing revealed that he has harbored compound heterozygous variants of the ACADVL gene, namely c.664G>A (p.G222R) and c.1345G>A (p.E449K), which were respectively derived from his father and mother. The child was diagnosed with VLCADD cardiomyopathy type and deceased 2 weeks later. Literature review has identified 60 Chinese children with VLCADD. The clinical classifications were mainly cardiomyopathy type and liver disease type, which accounted for 73.3% (43/60). The combination of ACADVL gene variants were correlated with the clinical classifications of VLCAD. Children with one or two loss-of-function (LOF) mutations showed more severe clinical manifestation and a higher mortality. Cardiomyopathy type had the poorest prognosis, with a mortality rate of 76.9% (20/26). C14:1 may be used as an indicator for the diagnosis of VLCADD, but cannot be used for clinical subtyping and prognosis evaluation. The c.1349G>A (p.R450H) variant had the highest frequency among the Chinese patients, accounting for 10.8% (13/120). CONCLUSION: The clinical classifications of VLCADD are strongly correlated with the prognosis, and LOF mutations are more common in those with severe clinical manifestations. c.1349G>A (p.R450H) may be the most common variant among the Chinese patients, and early screening and diagnosis can greatly improve the prognosis of patients.

A novel pathogenic variant in the carnitine transporter gene, SLC22A5, in association with metabolic carnitine deficiency and cardiomyopathy features.

BACKGROUND: Primary carnitine deficiency (PCD) denotes low carnitine levels with an autosomal recessive pattern of inheritance. Cardiomyopathy is the most common cardiac symptom in patients with PCD, and early diagnosis can prevent complications. Next-generation sequencing can identify genetic variants attributable to PCD efficiently. OBJECTIVE: We aimed to detect the genetic cause of the early manifestations of hypertrophic cardiomyopathy and metabolic abnormalities in an Iranian family. METHODS: We herein describe an 8-year-old boy with symptoms of weakness and lethargy diagnosed with PCD through clinical evaluations, lab tests, echocardiography, and cardiac magnetic resonance imaging. The candidate variant was confirmed through whole-exome sequencing, polymerase chain reaction, and direct Sanger sequencing. The binding efficacy of normal and mutant protein-ligand complexes were evaluated via structural modeling and docking studies. RESULTS: Clinical evaluations, echocardiography, and cardiac magnetic resonance imaging findings revealed hypertrophic cardiomyopathy as a clinical presentation of PCD. Whole-exome sequencing identified a new homozygous variant, SLC22A5 (NM_003060.4), c.821G > A: p.Trp274Ter, associated with carnitine transport. Docking analysis highlighted the impact of the variant on carnitine transport, further indicating its potential role in PCD development. CONCLUSIONS: The c.821G > A: p.Trp274Ter variant in SLC22A5 potentially acted as a pathogenic factor by reducing the binding affinity of organic carnitine transporter type 2 proteins for carnitine. So, the c.821G > A variant may be associated with carnitine deficiency, metabolic abnormalities, and cardiomyopathic characteristics.

Neutral lipid storage disease with myopathy: clinicopathological and genetic features of nine Iranian patients.

The rare disorder known as Neutral Lipid Storage Disease with Myopathy presents with a variety of clinical manifestations, including myopathy, cardiac dysfunction, and other organ complications. Early diagnosis is crucial due to the increased risk of cardiomyopathy. We describe the clinical, histopathological, muscle imaging, and genetic findings of nine neutral lipid storage myopathy patients. Proximal weakness and asymmetric involvement may suggest lipid storage myopathy. While skeletal muscle weakness was the main manifestation in our patients, one case presented only with hyperCKemia. Additionally, three patients had fertility issues, two suffered from diabetes mellitus, two had cardiomyopathy, and one had a history of hypothyroidism. Muscle histopathology revealed lipid depositions and rimmed vacuoles, prompting peripheral blood smears to detect Jordan Anomalies. All muscle biopsies and peripheral blood smear showed lipid droplets, rimmed vacuoles, and Jordan anomaly. Identifying PNPLA2 gene mutations is important for diagnosing neutral lipid storage myopathy; our cases showed some novel mutations. This study highlights the importance of early diagnosis and comprehensive evaluation in managing neutral lipid storage myopathy cases.

Myopathies of endocrine origin: A review for physicians.

Myopathies are a common manifestation of endocrine disorders. Endocrine myopathies are often overlooked while considering differential diagnoses in patients with musculoskeletal symptoms. The hindrance to mobility and the musculoskeletal discomfort owing to these myopathies are important causes of disability and depreciated quality of life in these patients. Endocrine myopathies occur due to the effects of endogenous or iatrogenic hormonal imbalance on skeletal muscle protein and glucose metabolism, disrupting the excitation-contraction coupling. Abnormalities of the pituitary, thyroid, parathyroid, adrenal, and gonadal hormones have all been associated with myopathies and musculoskeletal symptoms. Endocrine myopathies can either be the complication of a secondary endocrine disorder or a presenting symptom of a missed underlying disorder. Therefore, an underlying endocrine abnormality must always be excluded in all patients with musculoskeletal symptoms. This review presents a compilation of various endocrine myopathies, their etiopathogenesis, clinical presentation, diagnostic modalities, and treatment protocols.

Patient-reported muscle symptoms and their characterization in a hypertensive population eligible for statin therapy: An exploratory study.

BACKGROUND AND AIMS: Statin-associated muscle symptoms (SAMS) are claimed to be frequent in clinical practice. We evaluated the prevalence and characteristics of patient-reported muscle symptoms (PRMS) attributed to drugs/nutraceuticals in hypertensive patients, focusing the attention on statin treatment. METHODS AND RESULTS: Observational study on 390 consecutive outpatients. All patients were asked the following question: "Have you ever taken a drug/nutraceutical that you think gave you muscle symptoms?". Patients who answered "yes" were evaluated with a modified version of the SAMS-clinical index (SAMS-CI). Mean age: 60.5 ± 13.5 years (males 53.8%.). Patients who have ever taken a statin: 250. Patients who have never taken a statin: 140. Prevalence of PRMS (48.5% of the entire study population) did not differ between groups (p = 0.217). Only age, followed by number of drugs taken, was significantly associated with PRMS at multivariate analysis. A high prevalence of low scores to all the questions of "modified" SAMS-CI was found in both groups. Localization and pattern of PRMS did not differ between groups (p = 0.170). Timing of PRMS onset after starting the drug (p = 0.036) and timing of improvement after withdrawal (p = 0.002) were associated with statin therapy. CONCLUSION: PRMS are highly prevalent among the hypertensive population and are believed to be drug-related, especially with aging and regardless of whether the drug taken is a statin or not. These findings are in line with the growing evidence that subjective muscle symptoms are often misattributed to statins, while they may more likely be related to the nocebo/drucebo effect or to other common undiagnosed conditions.

Trauma in the elderly: a bilateral rectus sheath haematoma.

Life expectancy has more than doubled in the last century, and a new cohort of elderly and increasingly frail patients is presenting to emergency departments with new clinical challenges. When this patient cohort presents after injury, all aspects of clinical practice have to be recalibrated to provide safe and appropriate care. The prevalence of chronic disease, levels of organ failure, multiple comorbidities, greater use of anticoagulation and incidence of recurrent low- and high-impact trauma may delay and obscure diagnosis and, ultimately, increase mortality.Older age is a risk factor for rectus sheath haematoma (RSH), which is haemorrhage into the potential space surrounding the rectus abdominis muscle/s. It is a rare presentation following trauma but can provide diagnostic challenges and be fatal. Even more rare is bilateral RSH with only 12 reported in the literature since 1981.This case report describes bilateral RSH presenting in an elderly woman following a fall and the consequences of seemingly minor trauma in the elderly.

Unveiling the Rare Complication: Statin-Induced Immune-Mediated Necrotizing Myopathy.

BACKGROUND Statin-induced necrotizing autoimmune myopathy is an exceptionally rare yet severe complication of statin therapy that may develop in individuals at any time during their exposure to statins. The development of proximal muscle weakness, muscle pain, and elevated creatine kinase (CK) levels in patients while taking statins should prompt clinical consideration of statin-induced myopathy. The pathophysiology arises from the production of auto-antibodies, which target the 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase) enzyme, leading to the aggressive breakdown of myofibrils. CASE REPORT Here, we present a case of a 59-year-old woman with a medical history of dyslipidemia who developed anti-HMG-CoA reductase antibodies after taking atorvastatin. She came to the emergency department with complaints of severe proximal muscle weakness. The laboratory workup showed an elevated CK level up to 12 000 IU/L. Despite discontinuing atorvastatin, the patient's elevated CK levels persisted. The patient underwent a muscle biopsy, demonstrating myofibril necrosis. Serological analysis showed anti-HMG-CoA reductase antibodies in the patient's serum, which led to the diagnosis of immune-mediated necrotizing myopathy due to statins. The patient's statin therapy was promptly discontinued, and she was treated with a high dose of IV corticosteroids. After the patient's discharge, brief discontinuation of the corticosteroids resulted in CK elevation and a return of symptoms. This led to the second re-admission and restarting of corticosteroids until stabilization and discharge. CONCLUSIONS This case represents an important reminder for clinicians to recognize the possibility of statin-induced immune-mediated necrotizing myopathy in patients presenting with proximal muscle weakness while taking a statin, notwithstanding the rarity of this condition.