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Objective The objective of this study was to analyse the clinico–serological and histological phenotypes of patients with SSc with associated myopathy. Methods From November 2002 to September 2020, 52 patients with SSc underwent a muscle biopsy for suspected myopathy. We established two subgroups according to the histological findings based on the presence of isolated fibrosis or fibrosis together with significant inflammation. These patterns were designated as fibrosing and inflammatory, respectively. Clinical data, antibody profile, electrophysiologic studies, muscle biopsy findings and data regarding treatment, mortality and survival were compared between the two groups. Results Fourteen biopsies had a fibrosing pattern, whereas 26 showed an inflammatory pattern that could be classified (according to the predominant pattern) into DM (n = 7), necrotizing myopathy (n = 4) and non-specific myositis (n = 15). Additionally, 12 muscle biopsies were reported as neurogenic atrophy (n = 2), or normal muscle or minimal changes (n = 10). Compared with the inflammatory group, SSc patients with the fibrosing pattern presented a higher prevalence of ischaemic heart disease (38.5% vs 3.8%, P = 0.011), conduction abnormalities or arrhythmias (61.5% vs 26.9%, P = 0.036), anti-topo I antibodies (42.9% vs 11.5%, P = 0.044), greater median ESR (53.5 mm/h vs 32.5 mm/h, P = 0.013), with poor response to treatment and a higher mortality (42.9% vs 3.8%, P = 0.004) and lower cumulative survival (P = 0.035). Conclusions Patients with SSc-associated myopathy require a comprehensive approach that encompasses clinical, serological and histopathological aspects, given their outcome predictive capacity. At least two different phenotypes can be drawn, considering clinico–pathological features. Significant differences are delineated between both a fibrotic and an inflammatory phenotype.

ObjectiveDiagnostic muscle biopsies are routinely immunostained for major histocompatibility complex class I (MHC-I) protein. In this study we analysed the prevalence and patterns of MHC-I immunostaining in biopsies from patients with different types of myopathies and neurogenic disorders.MethodsAll 357 diagnostic muscle biopsies processed at the Johns Hopkins Neuromuscular Pathology Laboratory from August 2013 to January 2017 were immunostained for MHC-I. The prevalence and patterns of MHC-I immunostaining were compared between patients with histologically normal muscle biopsies (n = 31), idiopathic inflammatory myopathies (IIMs; n = 170), non-inflammatory myopathies (n = 60) and neurogenic disorders (n = 96).ResultsMHC-I immunostaining was abnormal in most patients with DM (98%), sporadic IBM (sIBM; 100%), immune-mediated necrotizing myopathy (IMNM; 100%) and polymyositis (77%). In contrast, MHC-I immunostaining was less frequently present in non-inflammatory myopathies (32%) or neurogenic disorders (30%). Overall, abnormal MHC-I immunostaining had a sensitivity of 0.95 and a specificity of 0.82 for diagnosing IIMs. A focal MHC-I staining pattern was associated with IMNM, whereas a global pattern was more prevalent in sIBM and a perifascicular pattern was significantly more common in dermatomyositis. Among 18 DM biopsies without perifascicular atrophy, 50% had a perifascicular MHC-I staining pattern. Sarcoplasmic upregulation staining was more common than sarcolemmal staining across all groups.ConclusionMHC-I immunostaining was useful to distinguish IIMs from non-inflammatory myopathies or neurogenic disorders. Of note, a perifascicular MHC-I staining pattern was present only in those with DM, including half of those without perifascicular atrophy; many of these biopsies may not otherwise have been diagnostic for DM.

Purpose of review Necrotizing myopathy is a broad term. It includes patients with the recently described immune-mediated necrotizing myopathies (IMNM) who have specific antibodies, such as anti-hydroxy-3-methylglutaryl-CoA reductase or anti-signal recognition particle, seronegative phenotypes that can be associated with cancer, and other types of myositis and connective tissue diseases involving necrotic muscle fibers as a characteristic pathologic feature. Necrotizing myopathies that are not immune-mediated, such as those caused by drugs, dystrophies, infections, or even hypothyroidism are also included. The purpose of this review is to address the differential diagnosis of these disorders. Recent findings New IMNM have been described over the last few years, some of them related with checkpoint inhibitors, drugs that are being increasingly used in cancer treatment. Necrotizing myopathy has also been reported in association with specific phenotypes and autoantibodies (e.g. anti-Mi2 dermatomyositis, antisynthetase syndrome, and myositis associated with antimitochondrial antibodies). Rarer cases associated with graft-versus-host disease and severe acute respiratory syndrome coronavirus 2 infection are also emerging. Summary Differentiation between patients with IMNM and those without the superimposed autoimmune phenomena helps clinicians determine the best individualized approach to use and the appropriate immunosuppressive therapy, whenever needed.

Anoctamin 5 (ANO5) is a putative intracellular calcium-activated chloride channel. Recessive mutations in ANO5 may present from asymptomatic hyperCKemia and exercise-induced myalgia to proximal and/or distal muscle weakness. Here we describe the clinical, pathological, and molecular findings of three unrelated patients with ANO5-related muscular dystrophy. In this retrospective study, we analyzed our database which includes 1700 muscle biopsies performed for diagnostic purposes from October 2004 to February 2019. Patients were attended by two myology experts, who performed and analyzed the muscle biopsies. Muscle biopsies were frozen in cooled isopenthane, cryostat sectioned, and routinely stained and reacted (minimum 16 stainings). A custom panel, including 115 genes (Nextera Rapid Capture, Illumina) and whole-exome sequencing analysis, was used for next-generation sequencing in cases without a definite pathological diagnosis. Three patients were diagnosed with ANO5-related muscular dystrophy, with all presenting the common exon 5 mutation c.191dup plus a compound heterozygous missense mutation. They showed three different phenotypes (distal myopathy, LGMD2L, and asymptomatic hyperCKemia). Curiously, all three muscle biopsies showed different patterns, but numerous ragged-red fibers with little endomysial inflammation and partial invasion cell by T lymphocytes were observed in one. ANO5-related muscular dystrophy is a heterogeneous disease with different clinical phenotypes as well as different histological patterns, which may even mimic a mitochondrial myopathy. The results of this study provide further knowledge of the clinical, histological, and pathological features related to ANO5 mutations.

To analyze the clinico-serological and histological phenotype of patients with systemic sclerosis (SSc) with associated myopathy.From November 2002 to September 2020, 52 patients with SSc underwent a muscle biopsy for suspected myopathy. We established two subgroups according to the histological findings based on the presence of isolated fibrosis or fibrosis together with significant inflammation. These patterns were designated as fibrosing and inflammatory, respectively. Clinical data, antibody profile, electrophysiologic studies, muscle biopsy findings and data regarding treatment, mortality and survival were compared between the 2 groups.Fourteen biopsies had a fibrosing pattern whereas 26 showed an inflammatory pattern that could be classified attending the predominant pattern into dermatomyositis (DM) (n = 7), necrotizing myopathy (n = 4) and non-specific myositis (n = 15). Additionally, 12 muscle biopsies were reported as neurogenic atrophy (n = 2) and normal muscle or minimal changes (n = 10). Compared with the inflammatory group, SSc patients with fibrosing pattern presented a higher prevalence of ischemic heart disease (38.5% vs 3.8%, p= 0.011), conduction abnormalities or arrhythmias (61.5% vs 26.9%, p= 0.036), anti-topoisomerase I antibodies (42.9% vs 11.5%, p= 0.044), greater median erythrocyte sedimentation rate (53.5 mm/h vs 32.5 mm/h, p= 0.013), with poor response to treatment and a higher mortality (42.9% vs 3.8%, p = 0.004) and lower cumulative survival (p= 0.035).Patients with SSc-associated myopathy require a comprehensive approach that encompasses clinical, serological, and histopathological aspects given their outcome predictive capacity. At least two different phenotypes can be drawn considering clinic-pathological features. Significant differences are delineated between both a fibrotic and an inflammatory phenotype.

Background and objectives Sporadic inclusion body myositis (sIBM) diagnosis is frequently delayed or confused with another class of disorders, and misdiagnosis is common. Sometimes, we have problems diagnosing an sIBM in the early stages or predicting when a PM is going to become an sIBM. In this sense, we believe that p62 immunostaining could help clinicians. Case report We report the case of a 61-year-old patient with sIBM who six years earlier had been diagnosed with polymyositis (PM). After muscle biopsies analyses, we showed the natural history of sIBM by p62 expression. Results When we looked for p62 aggregates retrospectively we could see small dotted p62 aggregates in the muscle fibres of the first muscle biopsy. Six years later, the patient presented with the typical clinical picture of sIBM, also the muscle biopsy was characteristic, with large p62 aggregates. Conclusions Probably p62 immunostaining could help to distinguish PM patients that are going to become sIBM, but to date there has been no systematic study to clarify p62 utility in myositis.

Objective Although more than a dozen myositis-specific autoantibodies (MSAs) have been identified, most patients with myositis are positive for a single MSA. The specific overexpression of a given myositis autoantigen in myositis muscle has been proposed as initiating and/or propagating autoimmunity against that particular autoantigen. The present study was undertaken to test this hypothesis. Methods In order to quantify autoantigen RNA expression, RNA sequencing was performed on muscle biopsy samples from control subjects, MSA-positive patients with myositis, regenerating mouse muscles, and cultured human muscle cells. Results Muscle biopsy samples were available from 20 control subjects and 106 patients with autoantibodies recognizing hydroxymethylglutaryl-coenzyme A reductase (n = 40), signal recognition particles (n = 9), Jo-1 (n = 18), nuclear matrix protein 2 (n = 12), Mi-2 (n = 11), transcription intermediary factor 1γ (n = 11), or melanoma differentiation-associated protein 5 (n = 5). The increased expression of a given autoantigen in myositis muscle was not associated with autoantibodies recognizing that autoantigen (all q > 0.05). In biopsy specimens from both myositis muscle and regenerating mouse muscles, autoantigen expression correlated directly with the expression of muscle regeneration markers and correlated inversely with the expression of genes encoding mature muscle proteins. Myositis autoantigens were also expressed at high levels in cultured human muscle cells. Conclusion Most myositis autoantigens are highly expressed during muscle regeneration, which may relate to the propagation of autoimmunity. However, factors other than overexpression of specific autoantigens are likely to govern the development of unique autoantibodies in individual patients with myositis.

ObjectiveTo accurately categorize the phenotypes of individuals with collagen VI–related dystrophies (COL6-RDs) during the first years of life to predict long-term motor function and pulmonary function, to provide phenotype-specific anticipatory care, and to improve clinical trial readiness.MethodsThis retrospective, multicenter, international study analyzed the relationship of long-term motor and pulmonary function with the initial maximal motor ability achieved in individuals with COL6-RD.ResultsWe studied 119 patients with COL6-RD from Spain (n = 54) and the United States (n = 65). The early maximal motor milestones of ability to rise from the floor unassisted and ability to climb 4 steps without holding onto a railing demonstrated reliability in distinguishing between 3 COL6-RD phenotypic subgroups: (1) Ullrich congenital muscular dystrophy, (2) intermediate COL6-RD, and (3) Bethlem myopathy. Long-term motor function and pulmonary function are strongly correlated with the maximal motor ability achieved during the first years of life. Maximal motor capacity can predict other disease-relevant events such as the age at loss of ambulation and the need for the initiation of nocturnal noninvasive ventilation.ConclusionThis work proposes a prospective phenotypic classification for COL6-RDs that will enable an accurate prediction of a patient's COL6-RD phenotype during the first years of life. The ability to establish a patient's COL6-RD phenotypic classification early will enable a more accurate prognosis of future motor and pulmonary function, thus improving anticipatory clinical care, and it will be instrumental in aiding the design of future clinical trials by allowing early stratification of trial cohorts.

Thank you for your constructive comments.1 We agree that transcriptomic data from affected muscle tissue have the potential to improve the diagnosis and treatment of inflammatory myopathies.2 First, transcriptomic data may allow us to identify the most relevant inflammatory pathways in a particular patient and thereby individualise therapy. For example, patients with marked upregulation of interferon-induced genes may benefit most from treatment with Janus kinase inhibitors. Second, transcriptomic analysis requires very little muscle tissue while providing a large amount of biological information. Thus, transcriptomic analysis using needle muscle biopsies may be as diagnostically useful as conventional surgical muscle biopsies. Finally, visual interpretation of muscle biopsies is a complicated task that, even when performed by experts, has relatively poor interrater reliability.3 In contrast, the analysis of transcriptomic data is objective and can be automated. In our study, the presence of interstitial lung disease was almost always present in certain myositis subgroups (anti-MDA54 and anti-Jo15) and almost completely absent in others (anti-Mi2,6 anti-NXP2,7 anti-TIF1g,8 anti-SRP,9 anti-HMGCR,10 IBM11).Thus, the sample size of patients with and without interstitial lung disease within each subgroup was not sufficient …

Background and aim There is increasing interest regarding SARS-CoV-2 infection in patients with autoimmune and immune-mediated inflammatory diseases (AI/IMID) with some discrepancies in different cohorts about their risk and outcomes. The aim was to describe a multidisciplinary cohort of patients with AI/IMID and symptomatic SARS-CoV-2 infection in a single tertiary center and analyze sociodemographic, clinical, and therapeutic factors associated with poor outcomes. Methods A retrospective observational study was conducted from the 1st of March until May 29th, 2020 in a University tertiary hospital in Barcelona, Spain. Patients with an underlying AI/IMID and symptomatic SARS-CoV-2 infection were identified in our local SARS-CoV-2 infection database. Controls (2:1) were selected from the same database and matched by age and gender. The primary outcome was severe SARS-CoV-2 infection, which was a composite endpoint including admission to the intensive care unit (ICU), need for mechanical ventilation (MV), and/or death. Several covariates including age, sex, and comorbidities among others were combined into a multivariate model having severe SARS-CoV-2 as the dependent variable. Also, a sensitivity analysis was performed evaluating AID and IMID separately. Results The prevalence of symptomatic SARS-CoV-2 infection in a cohort of AI/IMID patients was 1.3%. Eighty-five patients with AI/IMID and symptomatic SARS-CoV-2 were identified, requiring hospitalization in 58 (68%) cases. A total of 175 patients admitted for SARS-CoV-2 (58 with AI/IMID and 117 matched-controls) were analyzed. In logistic regression analysis, a significant inverse association between AI/IMID group and severe SARS-CoV-2 (OR 0.28; 95% CI 0.12–0.61; p = 0.001), need of MV (OR 0.20; IC 95% 0.05–0.71; p = 0.014), and ICU admission (OR 0.25; IC 95% 0.10–0.62; p = 0.003) was found. Conclusions Patients with AI/IMID who require admission for SARS-CoV-2 infection have a lower risk of developing severe disease, including the need to stay in the ICU and MV., Highlights • Patients with AI/IMID fwho required admission for SARS CoV2 infection have a lower risk of developing severe disease. • Among patients with AID and IMID, there were no differences in terms of severity. • According to the 7-category ordinal scale, maximum oxygen requirement was lower among AI/IMID group.

To investigate the clinical characteristics and outcome of octogenarians with covid-19.This is a observational, retrospective, descriptive study.Consecutive patients aged >80 years who were admitted for covid-19 pneumonia during a 6 weeks period (March 20-April 30, 2020).Illness severity on admission was classified according to World Health Organization (WHO) criteria: mild, moderate, severe, and critical. Data collected included demographics, presenting symptoms, radiological and laboratory findings, comorbidities, functional status, treatment, and clinical outcome.There were 159 patients (52.2% women) with a median age of 85.99 (IQR: 80-98). The median Barthel index was 90 (40-100) and Charlson index was 5 (5-6). Most common presenting symptoms were fever, dyspnea, and cough. Patients had mild (8.2%), moderate (52.2%), or severe (39.6%) illness according to WHO criteria. A bilateral pulmonary involvement was seen in 86% of patients. Laboratory analysis revealed increased serum concentrations of inflammatory parameters (C-reactive protein, ferritin, lactate dehydrogenase, and D-dimer) with an abnormal lymphocyte count [0.88 × 109/L (0.5)]. Treatments included corticosteroids in 37%, and biological therapies in 17.6%. Fifty three (33.3%) patients died during hospitalization, with a median time from admission to death of 3 (IQR 1-6) days. Mortality was higher in men (55%). Deceased patients had a significantly higher frequency of dyspnea, increased inflammatory parameters, and illness severity compared to survivors.One-third of octogenarians with covid-19 died during hospitalization and most had bilateral lung involvement. A further knowledge of the characteristics and outcome of this population may assist clinicians in the decision-making process in these patients.

Background Myositis, or idiopathic inflammatory myopathy (IIM), is a group disorders of unknown etiology characterized by the inflammation of skeletal muscle. The role of T cells and their antigenic targets in IIM initiation and progression is poorly understood. T cell receptor (TCR) repertoire sequencing is a powerful approach for characterizing complex T cell responses. However, current TCR sequencing methodologies are complex, expensive, or both, greatly limiting the scale of feasible studies. Methods Here we present Framework Region 3 AmplifiKation sequencing (“FR3AK-seq”), a simplified multiplex PCR-based approach for the ultra-efficient and quantitative analysis of TCR complementarity determining region 3 (CDR3) repertoires. By using minimal primer sets targeting a conserved region immediately upstream of CDR3, undistorted amplicons are analyzed via short read, single-end sequencing. We also introduce the novel algorithm Inferring Sequences via Efficiency Projection and Primer Incorporation (“ISEPPI”) for linking CDR3s to their associated variable genes. Findings We find that FR3AK-seq is sensitive and quantitative, performing comparably to two different industry standards. FR3AK-seq and ISEPPI were used to efficiently and inexpensively characterize the T cell infiltrates of surgical muscle biopsies obtained from 145 patients with IIM and controls. A cluster of closely related TCRs was identified in samples from patients with sporadic inclusion body myositis (IBM). Interpretation The ease and minimal cost of FR3AK-seq removes critical barriers to routine, large-scale TCR CDR3 repertoire analyses, thereby democratizing the quantitative assessment of human TCR repertoires in disease-relevant target tissues. Importantly, discovery of closely related TCRs in muscle from patients with IBM provides evidence for a shared antigen-driven T cell response in this disease of unknown pathogenesis. Funding This work was supported by NIH grant U24AI118633 and a Prostate Cancer Foundation Young Investigator Award.

Sporadic inclusion body myositis (sIBM) is an inflammatory myopathy associated, among others, with mitochondrial dysfunction. Similar molecular features are found in Alzheimer’s disease (AD) and Type 2 Diabetes Mellitus (T2DM), underlying potential comorbidity. This study aims to evaluate common clinical and molecular hallmarks among sIBM, AD, and T2DM. Comorbidity with AD was assessed in n = 14 sIBM patients by performing neuropsychological and cognitive tests, cranial magnetic resonance imaging, AD cerebrospinal fluid biomarkers (levels of amyloid beta, total tau, and phosphorylated tau at threonine-181), and genetic apolipoprotein E genotyping. In the same sIBM cohort, comorbidity with T2DM was assessed by collecting anthropometric measures and performing an oral glucose tolerance test and insulin determinations. Results were compared to the standard population and other myositis (n = 7 dermatomyositis and n = 7 polymyositis). Mitochondrial contribution into disease was tested by measurement of oxidative/anaerobic and oxidant/antioxidant balances, respiration fluxes, and enzymatic activities in sIBM fibroblasts subjected to different glucose levels. Comorbidity of sIBM with AD was not detected. Clinically, sIBM patients showed signs of misbalanced glucose homeostasis, similar to other myositis. Such misbalance was further confirmed at the molecular level by the metabolic inability of sIBM fibroblasts to adapt to different glucose conditions. Under the standard condition, sIBM fibroblasts showed decreased respiration (0.71 ± 0.08 vs. 1.06 ± 0.04 nmols O2/min; p = 0.024) and increased anaerobic metabolism (5.76 ± 0.52 vs. 3.79 ± 0.35 mM lactate; p = 0.052). Moreover, when glucose conditions were changed, sIBM fibroblasts presented decreased fold change in mitochondrial enzymatic activities (−12.13 ± 21.86 vs. 199.22 ± 62.52 cytochrome c oxidase/citrate synthase ratio; p = 0.017) and increased oxidative stress per mitochondrial activity (203.76 ± 82.77 vs. −69.55 ± 21.00; p = 0.047), underlying scarce metabolic plasticity. These findings do not demonstrate higher prevalence of AD in sIBM patients, but evidences of prediabetogenic conditions were found. Glucose deregulation in myositis suggests the contribution of lifestyle conditions, such as restricted mobility. Additionally, molecular evidences from sIBM fibroblasts confirm that mitochondrial dysfunction may play a role. Monitoring T2DM development and mitochondrial contribution to disease in myositis patients could set a path for novel therapeutic options.

Magnetic resonance imaging (MRI) is considered the most sensitive and specific imaging technique for the detection of muscle diseases related to myopathies. Since 2008, the use of whole-body MRI (WBMRI) to evaluate myopathies has improved due to technical advances such as rolling table platform and parallel imaging, which enable rapid assessment of the entire musculoskeletal system with high-quality images. WBMRI protocols should include T1-weighted and short-tau inversion recovery (STIR), which provide the basic pulse sequences for studying myopathies, in order to detect fatty infiltration/muscle atrophy and muscle edema, respectively. High signal intensity in T1-weighted images shows chronic disease with fatty infiltration, whereas high signal intensity in STIR indicates an acute stage with muscle edema. Additional sequences such as diffusion-weighted imaging (DWI) can be readily incorporated into routine WBMRI study protocols. Contrast-enhanced sequences have not been done. This article reviews WBMRI as an imaging method to evaluate different myopathies (idiopathic inflammatory, dystrophic, non-dystrophic, metabolic, and channelopathies). WBMRI provides a comprehensive estimate of the total burden with a single study, seeking specific distribution patterns, including clinically silent involvement of muscle areas. Furthermore, WBMRI may help to select the "target muscle area" for biopsy during patient follow-up. It may be also be used to detect related and non-related pathological conditions, such as tumors.

Objectives. To analyse the influence of genetic alterations and differential expression of transcription intermediary factor 1 (TIF1) genes in the pathophysiology of cancer-associated myositis (CAM). Methods. Paired blood and tumour DNA samples from patients with anti-TIF1 gamma-positive CAM and from controls were analysed by whole-exome sequencing for the presence of somatic mutations and loss of heterozygosity (LOH) in their TIF1 genes. The genesis and maintenance of the autoimmune process were investigated immunohistochemically by studying TIF1 gamma expression in the different tissues involved in CAM (skin, muscle and tumour) based on the immunohistochemical H-score. Results. From seven patients with anti-TIF1 gamma-positive CAM, we detected one somatic mutation and five cases of LOH in one or more of the four TIF1 genes compared with just one case of LOH in tumours from TIF1 gamma-negative myositis patients (86% vs 17%; P = 0.03). Compared with type-matched control tumours from non-myositis patients, TIF1 gamma staining was more intense in tumours from anti-TIF1 gamma-positive patients (H-score 255 vs 196;P = 0.01). Also, TIF1 gamma staining in muscle was slightly more intense in anti-TIF1 gamma-positive than in anti-TIF1 gamma-negative myositis (H-score 22 vs 5; P = 0.03). In contrast, intense TIF1 gamma staining was detected in the skin of both myositis and control patients. Conclusion. Tumours from paraneoplastic anti-TIF1 gamma-positive patients showed an increased number of genetic alterations, such as mutations and LOH, in TIF1 genes. These genetic alterations, in the context of a high expression of TIF1 gamma in the tumour, muscle and skin of these patients may be key to understanding the genesis of paraneoplastic myositis.

Resumen Introduccion Las miopatias, ya sean hereditarias o adquiridas, son enfermedades poco frecuentes, considerandose dificil su abordaje diagnostico. A pesar de los avances cientificos, la historia clinica y el examen fisico siguen siendo la piedra angular para comenzar el estudio. Metodos complementarios diagnosticos Se utilizan diferentes metodos complementarios, como las enzimas musculares, el electromiograma, la resonancia magnetica muscular, la biopsia muscular y estudios moleculares cuando se precisan, para poder obtener un diagnostico especifico. Aun asi, en un considerable numero de casos no es posible llegar al diagnostico final. Seguramente en los siguientes anos, muchos de estos casos huerfanos dejaran de serlo, ya que continuamente se van descubriendo caracteristicas y/o aspectos que permiten una mejor comprension de las miopatias. En este protocolo se pretenden establecer los conceptos basicos para el planteamiento diagnostico de las enfermedades musculares en el adulto, sin contemplar las enfermedades de la union neuromuscular ni de la motoneurona, si bien es cierto que algunas de ellas entraran en el diagnostico diferencial en el estudio de las miopatias.

ObjectivesMyositis is a heterogeneous family of diseases that includes dermatomyositis (DM), antisynthetase syndrome (AS), immune-mediated necrotising myopathy (IMNM), inclusion body myositis (IBM), polymyositis and overlap myositis. Additional subtypes of myositis can be defined by the presence of myositis-specific autoantibodies (MSAs). The purpose of this study was to define unique gene expression profiles in muscle biopsies from patients with MSA-positive DM, AS and IMNM as well as IBM.MethodsRNA-seq was performed on muscle biopsies from 119 myositis patients with IBM or defined MSAs and 20 controls. Machine learning algorithms were trained on transcriptomic data and recursive feature elimination was used to determine which genes were most useful for classifying muscle biopsies into each type and MSA-defined subtype of myositis.ResultsThe support vector machine learning algorithm classified the muscle biopsies with >90% accuracy. Recursive feature elimination identified genes that are most useful to the machine learning algorithm and that are only overexpressed in one type of myositis. For example, CAMK1G (calcium/calmodulin-dependent protein kinase IG), EGR4 (early growth response protein 4) and CXCL8 (interleukin 8) are highly expressed in AS but not in DM or other types of myositis. Using the same computational approach, we also identified genes that are uniquely overexpressed in different MSA-defined subtypes. These included apolipoprotein A4 (APOA4), which is only expressed in anti-3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) myopathy, and MADCAM1 (mucosal vascular addressin cell adhesion molecule 1), which is only expressed in anti-Mi2-positive DM.ConclusionsUnique gene expression profiles in muscle biopsies from patients with MSA-defined subtypes of myositis and IBM suggest that different pathological mechanisms underly muscle damage in each of these diseases.

Objectives Statins are the cornerstone of the treatment and prevention of cardiovascular disease but have been associated with muscular side effects, among others. If patients are not properly evaluated, statin discontinuation may take place, leaving patients’ symptoms unresolved and precluding an effective cardiovascular treatment. The present study aims to describe the clinical characteristics, the diagnostic process and the final diagnosis of selected patients with suspected statin-induced myopathy, with quite different alternative diagnoses. Methods Among the 86 patients referred to our unit for evaluation since 2012, 6 patients with suspected statin-induced myopathy that was finally ruled out were selected as examples because of their illustrative value. All patients were evaluated in a Muscular Diseases Unit by myology experts, and additional testing was performed according to clinical suspicion. Results Of the six selected patients with suspected statin-induced myopathy, three had a neurogenic aetiology, two had vacuolar myopathies and one had severe hypothyroidism. Statins were permanently discontinued in two cases, with the treatment of one of the latter patients being continued with a protein convertase subtilisin/kexin type 9 (PCSK9) inhibitor. Conclusion Not all patients taking statins who develop muscle complaints have statin-related myopathy. A thorough clinical evaluation and appropriate testing is warranted to avoid an unnecessary increase in cardiovascular risk.

Idiopathic inflammatory myopathies (IIM) are characterized by muscle inflammation and weakness, myositis-specific autoantibodies (MSAs), and extramuscular organ damage. The role of neutrophil dysregulation and neutrophil extracellular traps (NETs) in IIM is unclear. We assessed whether pathogenic neutrophil subsets (low-density granulocytes [LDGs]) and NETs were elevated in IIM, associated with clinical presentation and MSAs, and their effect on skeletal myoblasts and myotubes. Circulating NETs and LDGs were quantified and correlated with clinical measures. Specific MSAs were tested for their ability to induce NETs. NETs and neutrophil gene expression were measured in IIM biopsies. Whether NETs damage skeletal myoblasts and myotubes was tested. Circulating LDGs and NETs were increased in IIM. IIM LDGs had an enhanced ability to form NETs. LDGs and NETs correlated with IIM disease activity and muscle damage. The serum MSA anti-MDA5 correlated with circulating and tissue NETs and directly enhanced NET formation. An enhanced neutrophil gene signature was present in IIM muscle and associated with muscle injury and tissue IFN gene signatures. IIM NETs decreased the viability of myotubes in a citrullinated histone-dependent manner. Dysregulated neutrophil pathways may play pathogenic roles in IIM through their ability to directly injure muscle cells and other affected tissues.

ObjectiveActivation of the type 1 interferon (IFN1) pathway is a prominent feature of dermatomyositis (DM) muscle and may play a role in the pathogenesis of this disease. However, the relevance of the IFN1 pathway in patients with other types of myositis such as the antisynthetase syndrome (AS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM) is largely unknown. Moreover, the activation of the type 2 interferon (IFN2) pathway has not been comprehensively explored in myositis. In this cross-sectional study, our objective was to determine whether IFN1 and IFN2 pathways are differentially activated in different types of myositis by performing RNA sequencing on muscle biopsy samples from 119 patients with DM, IMNM, AS, or IBM and on 20 normal muscle biopsies.MethodsThe expression of IFN1- and IFN2-inducible genes was compared between the different groups.ResultsThe expression of IFN1-inducible genes was high in DM, moderate in AS, and low in IMNM and IBM. In contrast, the expression of IFN2-inducible genes was high in DM, IBM, and AS but low in IMNM. The expression of IFN-inducible genes correlated with the expression of genes associated with inflammation and muscle regeneration. Of note, ISG15 expression levels alone performed as well as composite scores relying on multiple genes to monitor activation of the IFN1 pathway in myositis muscle biopsies.ConclusionsIFN1 and IFN2 pathways are differentially activated in different forms of myositis. This observation may have therapeutic implications because immunosuppressive medications may preferentially target each of these pathways.

Background The prevalence of myopathy in systemic sclerosis (SSc) or scleroderma patients varies from 5% to 81% depending on the diagnostic criteria used to define the muscle involvement. The histopathological characteristics found in these patients and their correlation with the clinical features and autoantibody profile has not been fully characterized. Objectives To characterize the muscle involvement and histopathology findings in patients with SSc. Methods This retrospective cross-sectional study included all patients from Scleroderma Cohort of Vall d’Hebron General and Hospital Clinic de Barcelona with muscle biopsies available for review performed at the Muscle Research Unit of Hospital Clinic de Barcelona from May 2004 to November 2018. Muscle biopsies were performed, for weakness or raised CK and/or aldolase. Histological sections were independently evaluated by two myopathology experts looking for inflammation in the endomisium, perimisium and perivascular areas. The presence of necrosis, regeneration, fibrosis, neurogenic atrophy, and fiber type grouping as well as perifascicular atrophy were also recorded. Based on the autoantibody profiles patients were classified into five groups, “Scl70”, “PM/Scl”, “centromere”, “U1-RNP”, and “nucleolar and centromer IFI ANA pattern without specificity for anti-Scl70 or anticentromer”. Demographic and clinical data were obtained by chart review. Results 42 subjects were included, 33 (78,6%) of them were women. Considering the immunological profile 12 had Scl70, 12 PM/Scl, 5 anticentromere, 2 U1RNP, and 11 had ANA pattern without specificity for anti-Scl70 or anticentromer. Most of patients (90.5%) were Caucasians, 2 (4.8%) were Hispanic, and 2 of other ethnic background. The mean age at the onset of SSc was 42.1 (SD 2.5) years and at the muscular symptoms 50.7 (SD 2.1) years, respectively. Twenty-two (52.4%) patients presented with high CK level (mean level of 1316 ± 353.8 U/L; normal value ≥200 U/L) whereas 38 (90.5%) exhibited high aldolase level (mean 19 ± 2.53 U/L, normal value Among the pathological features, 28 (66.7%) biopsies had fibrosis. Neurogenic atrophy was detected in 4 (9.5%) and fiber type grouping was present in 9 (21.4%) muscle biopsies. In near half of the muscle biopsies (45.2%) inflammatory infiltrate was present. Compared to other patients, those positive for PM/Scl had more perivascular (75%), endomysial (50%) and perimisial inflammation (75%) and perifascicular atrophy (42%) (all p Conclusion In our cohort of SSc patients with muscle involvement, two main histopathological patterns were found, fibrosis and inflammation. Almost half patients presented with elevated aldolase with normal CK levels. The muscle disease heterogeneity suggests that a variety of pathologic mechanisms play a role in the scleroderma associated myopathy but those patients with histopathological inflammatory features deserve to be treated with immunosuppressive therapy. References [1] Arthritis Care Res (Hoboken). 2015; 67: 1416-25 [2] Ther Adv Musculoskelet Dis. 2017; 9: 3–10. [3] Arthritis Res Ther. 2014; 16: R111. Disclosure of Interests None declared

Glycogen storage disorder type III (GSDIII), or debranching enzyme (GDE) deficiency, is a rare metabolic disorder characterized by variable liver, cardiac, and skeletal muscle involvement. GSDIII manifests with liver symptoms in infancy and muscle involvement during early adulthood. Muscle biopsy is mainly performed in patients diagnosed in adulthood, as routine diagnosis relies on blood or liver GDE analysis, followed by AGL gene sequencing. The GSDIII mouse model recapitulate the clinical phenotype in humans, and a nearly full rescue of muscle function was observed in mice treated with the dual AAV vector expressing the GDE transgene. In order to characterize GSDIII muscle morphological spectrum and identify novel disease markers and pathways, we performed a large international multicentric morphological study on 30 muscle biopsies from GSDIII patients. Autophagy flux studies were performed in human muscle biopsies and muscles from GSDIII mice. The human muscle biopsies revealed a typical and constant vacuolar myopathy, characterized by multiple and variably sized vacuoles filled with PAS-positive material. Using electron microscopy, we confirmed the presence of large non-membrane bound sarcoplasmic deposits of normally structured glycogen as well as smaller rounded sac structures lined by a continuous double membrane containing only glycogen, corresponding to autophagosomes. A consistent SQSTM1/p62 decrease and beclin-1 increase in human muscle biopsies suggested an enhanced autophagy. Consistent with this, an increase in the lipidated form of LC3, LC3II was found in patients compared to controls. A decrease in SQSTM1/p62 was also found in the GSDIII mouse model. In conclusion, we characterized the morphological phenotype in GSDIII muscle and demonstrated dysfunctional autophagy in GSDIII human samples. These findings suggest that autophagic modulation combined with gene therapy might be considered as a novel treatment for GSDIII.

Journal of neurology 266(3), 680-690 (2019). doi:10.1007/s00415-019-09187-2, Published by Springer, Berlin ; Heidelberg

Immune receptor repertoire (IRR) sequencing is increasingly employed to characterize adaptive immune responses. However, current IRR sequencing methodologies are complex, expensive, or both, thereby limiting routine utilization. Here we present Framework Region 3 AmplifiKation sequencing ("FR3AK-seq"), a simplified multiplex PCR-based approach for the ultra-efficient analysis of IRRs. By using minimal primer sets that target a conserved region adjacent to the hypervariable VDJ sequence, undistorted amplicon can be analyzed via short read, single-end sequencing. We find that FR3AK-seq is sensitive and quantitative, with a per sample cost of ~50-fold below the current industry standard. Inference of V-allele usage from FR3AK-seq data is demonstrated using a novel algorithm: Inferring Sequences via Efficiency Projection and Primer Incorporation ("ISEPPI"). FR3AK-seq and ISEPPI were utilized to quickly and inexpensively characterize the T cell infiltrates of 146 muscle biopsies obtained from patients with idiopathic inflammatory myopathies (IIMs) and controls. A cluster of related T cell receptors were identified in samples from patients with sporadic inclusion body myositis, suggesting the presence of an unknown shared antigen. The ease and cost of FR3AK-seq analysis removes the current barriers to routine, large-scale IRR analyses.

Sporadic inclusion body myositis (sIBM) is one of the most common myopathies in elderly people. Mitochondrial abnormalities at the histological level are present in these patients. We hypothesize that mitochondrial dysfunction may play a role in disease aetiology. We took the following measurements of muscle and peripheral blood mononuclear cells (PBMCs) from 30 sIBM patients and 38 age- and gender-paired controls: mitochondrial DNA (mtDNA) deletions, amount of mtDNA and mtRNA, mitochondrial protein synthesis, mitochondrial respiratory chain (MRC) complex I and IV enzymatic activity, mitochondrial mass, oxidative stress and mitochondrial dynamics (mitofusin 2 and optic atrophy 1 levels). Depletion of mtDNA was present in muscle from sIBM patients and PBMCs showed deregulated expression of mitochondrial proteins in oxidative phosphorylation. MRC complex IV/citrate synthase activity was significantly decreased in both tissues and mitochondrial dynamics were affected in muscle. Depletion of mtDNA was significantly more severe in patients with mtDNA deletions, which also presented deregulation of mitochondrial fusion proteins. Imbalance in mitochondrial dynamics in muscle was associated with increased mitochondrial genetic disturbances (both depletion and deletions), demonstrating that proper mitochondrial turnover is essential for mitochondrial homoeostasis and muscle function in these patients.

Introduction: Musculoskeletal manifestations are well-recognized side effects of treatment with statins. New advances in this field have appeared in recent years. This review focuses on the diagnosis of these conditions and their underlying pathogenesis, in particular immune-mediated necrotizing myopathy.Areas covered: Clinical phenotypes including rhabdomyolysis, myalgia and/or mild hyperCKemia, self-limited toxin statin myopathy, and immune-mediated necrotizing myopathy are herein described. Therapeutic recommendations and a diagnostic algorithm in statin-associated myopathy are also proposed. The etiology and pathogenesis of statin-induced myopathy has mainly focused on the anti-HMGCR antibodies and the responsibility of the immune-mediated necrotizing myopathy is discussed. The fact that patients who have not been exposed to statins may develop statin-associated autoimmune myopathy with anti-HMGCR antibodies is also addressed. The literature search strategy included terms identified by searches of PubMed between 1969 and December 2017. The search terms myositis', statin-induced autoimmune myopathy', immune-mediate necrotizing myopathy', statins', muscular manifestations', and anti-HMGCR antibodies' were used.Expert commentary: Full characterization of the known phenotypes of statin toxicity and the specific role of the anti-HMGCR in those exposed and not exposed (i.e. juvenile forms) to statins and in some types of neoplasms is of paramount relevance.

Domino liver transplantation, in which the liver from a patient with transthyretin-mediated amyloidosis (ATTR) is transplanted into another patient, is a well-established procedure.1,2 The figure is from 2 unrelated cases of liver transplant receptors from donors with ATTR who developed clinical polyneuropathy with weakness and paresthesia in lower extremities some years after the liver transplantation. In both cases, EMG showed distal sensory and motor polyneuropathy. Although amyloid neuropathy was the clinical suspicion, a muscle and nerve biopsy was performed in order to rule out other conditions.

Background Dermatomyositis represents one of the major forms among the inflammatory myopathies (IIM). Although the muscle biopsy remains the definitive test, MRI has been used to detect unique patterns of muscle involvement. To date, no studies have compared MRI with muscle pathology in naive DM. Objectives To compare the pattern of muscle MRI with muscle pathology. Methods All the patients enrolled in the Hospital Clinic de Barcelona (HCB) from January 2009 to December 2016 with an available MRI, performed just before muscle biopsy were included. The HCB ethics committee approved this study, and written informed consent was obtained from each participant. MRI data and the clinical and demographic features were prospectively collected. Patients were classified as having definite DM (ref 4). MRI was performed on a 1.5T with standardized protocol of whole body or scapular and pelvic girdle MRI, which include coronal and axial T1-weighted and STIR images. Image analysis was performed by two experienced musculoskeletal radiologists masked to the disease activity. The presence of oedema, fatty replacement and fascial oedema was evaluated in the biopsied muscle. Muscle and fascial inflammation was scored using a 0–3 point scale. The extent of muscle involvement was also evaluated by the analysis of 12 to 14 axial images and a percentage of muscle volume was calculated. Fatty replacement was scored using a 0–3 point scale. Muscle biopsies were evaluated by two trained pathologists at the HCB. Muscle biopsies were routinely processed. Quantification of fiber necrosis, regeneration and inflammation infiltrate were recorded. All statistical analyses were performed using “SPSS v22.0 ®”. In all statistical tests performed p value of 0.05 was considered significant. Results A total of 16 (13 female) patients were included. Except in one patient all of them had proximal muscle weakness, and all of them except one had typical DM skin lesions. In 12% of the patients a solid cancer was diagnosed. All patients had fascial edema at muscle MRI while no one had fatty replacement, and 65% had muscle oedema. Only one biopsy was normal. A significant correlation was found between muscle inflammation and MRI muscle edema (p=0,036) and the percentage of volume muscle involvement at MRI (p=0,027). Muscle necrosis was seen in those patients with moderate and severe fascial edema compared with those with mild fascial edema (p=0,032). More regenerating cells were seen in those patients with moderate and severe muscle edema compared with negative or mild muscle oedema (p=0,018). Conclusions A strong and significant correlation between histological and imaging findings was found. Fascial and muscle edema were the predominant findings in DM patients References Garcia J. MRI in inflammatory myopathies. Skeletal Radiol 2000;29:425–38. Connor A, Stebbings S, Hung N, et al. STIR MRI to Direct Muscle Biopsy in Suspected Idiopathic Inflammatory Myopathy. J Clin Rheumatol 2007;13: 341–45. Dalakas MC. Inflammatory muscle diseases. N Engl J Med 2015;373:393–4. Hoogendijk JE, Amato AA, Lecky BR, et al. 119th ENMC international workshop: trial design in adult idiopathic inflammatory myopathies, with the exception of inclusion body myositis, 10–12 October 2003, Naarden, the Netherlands. Neuromuscul Disord 2004;14:337–45. Disclosure of Interest None declared

The antibiotic linezolid is a ribosomal inhibitor with excellent efficacy. Although the administration period has been reduced to 28 days, side effects, usually of hematologic or neuropathic origin, are still reported due to secondary inhibition of mitochondrial protein synthesis. Susceptibility to linezolid toxicity remains unknown. Therefore, the objective of this study was to gain an understanding of clinical heterogeneity in response to identical linezolid exposures through exhaustive examination of the molecular basis of tissue-dependent mitotoxicity, consequent cell dysfunction, and the association of mitochondrial genetics with adverse effects of linezolid administered for the recommended period. Peripheral blood mononuclear cells (PBMC) and skin nerve fibers from 19 and 6 patients, respectively, were evaluated before and after a 28-day linezolid treatment in order to assess toxic effects on mitochondria and cells. Mitochondrial DNA haplotypes and single nucleotide polymorphisms (SNPs) in ribosomal sequences where linezolid binds to mitochondrial ribosomes were also analyzed to investigate their genetic contributions. We found that linezolid reduced mitochondrial protein levels, complex IV activity, and mitochondrial mass in PBMC and was associated with a trend toward an increase in the rate of apoptosis. In skin tissue, mitochondrial mass increased within nerve fibers, accompanied by subclinical axonal swelling. Mitochondrial haplogroup U, mutations in 12S rRNA, and the m.2706A→G, m.3197T→C, and m.3010G→A polymorphisms in 16S rRNA showed a trend toward an association with increased mitochondrial and clinical adverse effects. We conclude that even when linezolid is administered for a shorter time than formerly, adverse effects are reported by 63% of patients. Linezolid exerts tissue-dependent mitotoxicity that is responsible for downstream cellular consequences (blood cell death and nerve fiber swelling), leading to adverse hematologic and peripheral nervous side effects. Multicentric studies should confirm genetic susceptibility in larger cohorts.

OBJECTIVE To determine whether mitochondrial, oxidative, and apoptotic abnormalities in placenta derived from HIV and combined antiretroviral therapy (cART) containing zidovudine (AZT) could be associated with adverse perinatal outcome. DESIGN Cross-sectional, controlled, observational study. METHODS We studied obstetric results and mitochondrial, oxidative, and apoptotic state in placenta of 24 treated HIV-infected and 32 -uninfected pregnant women. We measured mitochondrial DNA (mtDNA) content by quantitative reverse transcriptase-polymerase chain reaction (mtND2/n18SrRNA), oxidative stress by the spectrophotometric quantification of lipid peroxidation and apoptosis by Western blot analysis of active caspase-3 respect to β-actin content and analysis of the terminal deoxynucleotidyl transferase dUTP nick end labeling. RESULTS Global adverse perinatal outcome (defined as preterm delivery or/and small newborns for gestational age) was significantly increased in HIV pregnancies [or 6.7 (1.3-33.2); P < 0.05]. mtDNA content in HIV-infected women was significantly depleted (39.20% ± 2.78%) with respect to controls (0.59 ± 0.03 vs. 0.97 ± 0.07; P < 0.001). A significant 29.50% ± 9.14% increase in oxidative stress was found in placentas of HIV-infected women (23.23 ± 1.64 vs. 17.94 ± 1.03; P < 0.01). A trend toward 41.18% ± 29.41% increased apoptosis active caspase-3/β-actin was found in HIV patients (0.48 ± 0.10 vs. 0.34 ± 0.05; P = not significant), confirmed by transferase dUTP nick end labeling assay. Adverse perinatal outcome did not correlate mitochondrial, oxidative, or apoptotic findings. CONCLUSIONS Placentas of HIV-infected pregnant women under AZT cART showed evidence of mtDNA depletion, increased oxidative stress levels, and apoptosis suggestive of secondary mitochondrial failure, potential base of associated adverse perinatal outcome. Despite the fact that further demonstration of causality would need new approaches and bigger sample sizes, AZT-sparing cART should be considered in the context of pregnancy.

Objective. To determine potential mitochondrial and oxidative alterations in colon biopsies from idiopathic REM sleep behavior disorder (iRBD) and Parkinson’s disease (PD) subjects. Methods. Colonic biopsies from 7 iRBD subjects, 9 subjects with clinically diagnosed PD, and 9 healthy controls were homogenized in 5% w/v mannitol. Citrate synthase (CS) and complex I (CI) were analyzed spectrophotometrically. Oxidative damage was assessed either by lipid peroxidation, through malondialdehyde and hydroxyalkenal content by spectrophotometry, or through antioxidant enzyme levels of superoxide dismutase-2 (SOD2), glutathione peroxidase-1 (Gpx1), and catalase (CAT) by western blot. The presence of mitochondrial DNA (mtDNA) deletions was assessed by long PCR and electrophoresis. Results. Nonsignificant trends to CI decrease in both iRBD (45.69±18.15; 23% decrease) and PD patients (37.57±12.41; 37% decrease) were found compared to controls (59.51±12.52, p: NS). Lipid peroxidation was maintained among groups (iRBD: 27.46±3.04, PD: 37.2±3.92, and controls: 31.71±3.94; p: NS). Antioxidant enzymes SOD2 (iRBD: 2.30±0.92, PD: 1.48±0.39, and controls: 1.09±0.318) and Gpx1 (iRBD 0.29±0.12, PD: 0.56±0.33, and controls: 0.38±0.16) did not show significant differences between groups. CAT was only detected in 2 controls and 1 iRBD subject. One iRBD patient presented a single mtDNA deletion.

Patients with inborn errors of metabolism (IEMs) have become an emerging and challenging group in the adult healthcare system whose needs should be known in order to implement appropriate policies and to adapt adult clinical departments. We aimed to analyze the clinical characteristics of adult patients with IEMs who attend the most important Spanish hospitals caring for these conditions. A cohort study was conducted in 500 patients, categorized by metabolic subtype according to pathophysiological classification. The most prevalent group of IEMs was amino acid disorders, with 108 (21.6%) patients diagnosed with phenylketonuria. Lysosomal storage disorders were the second group, in which 32 (6.4%) and 25 (5%) patients had Fabry disease and Gaucher disease respectively. The great clinical heterogeneity, the significant delay in diagnosis after symptom onset, the existence of some degree of physical dependence in a great number of patients, the need for a multidisciplinary and coordinated approach, and the lack of specific drug treatment are common features in this group of conditions.

To characterize mitochondrial/apoptotic parameters in chronically human immunodeficiency virus (HIV‐1)‐infected promonocytic and lymphoid cells which could be further used as therapeutic targets to test pro‐mitochondrial or anti‐apoptotic strategies as in vitro cell platforms to deal with HIV‐infection. Mitochondrial/apoptotic parameters of U1 promonocytic and ACH2 lymphoid cell lines were compared to those of their uninfected U937 and CEM counterparts. Mitochondrial DNA (mtDNA) was quantified by rt‐PCR while mitochondrial complex IV (CIV) function was measured by spectrophotometry. Mitochondrial‐nuclear encoded subunits II–IV of cytochrome‐c‐oxidase (COXII‐COXIV), respectively, as well as mitochondrial apoptotic events [voltage‐dependent‐anion‐channel‐1(VDAC‐1)‐content and caspase‐9 levels] were quantified by western blot, with mitochondrial mass being assessed by spectrophotometry (citrate synthase) and flow cytometry (mitotracker green assay). Mitochondrial membrane potential (JC1‐assay) and advanced apoptotic/necrotic events (AnexinV/propidium iodide) were measured by flow cytometry. Significant mtDNA depletion spanning 57.67% (P < 0.01) was found in the U1 promonocytic cells further reflected by a significant 77.43% decrease of mitochondrial CIV activity (P < 0.01). These changes were not significant for the ACH2 lymphoid cell line. COXII and COXIV subunits as well as VDAC‐1 and caspase‐9 content were sharply decreased in both chronic HIV‐1‐infected promonocytic and lymphoid cell lines (

To assess the impact of HIV‐infection and highly active anti‐retroviral treatment in mitochondria and apoptotic activation of caspases during pregnancy and their association with adverse perinatal outcome. Changes of mitochondrial parameters and apoptotic caspase activation in maternal peripheral blood mononuclear cells were compared at first trimester of pregnancy and delivery in 27 HIV‐infected and ‐treated pregnant women versus 24 uninfected pregnant controls. We correlated immunovirological, therapeutic and perinatal outcome with experimental findings: mitochondrial DNA (mtDNA) content, mitochondrial protein synthesis, mitochondrial function and apoptotic caspase activation. The HIV pregnancies showed increased adverse perinatal outcome (OR: 4.81 [1.14–20.16]; P < 0.05) and decreased mtDNA content (42.66 ± 5.94%, P < 0.01) compared to controls, even higher in naïve participants. This depletion caused a correlated decrease in mitochondrial protein synthesis (12.82 ± 5.73%, P < 0.01) and function (20.50 ± 10.14%, P < 0.001), not observed in controls. Along pregnancy, apoptotic caspase‐3 activation increased 63.64 ± 45.45% in controls (P < 0.001) and 100.00 ± 47.37% in HIV‐pregnancies (P < 0.001), in correlation with longer exposure to nucleoside analogues. HIV‐infected women showed increased obstetric problems and declined genetic and functional mitochondrial parameters during pregnancy, especially those firstly exposed to anti‐retrovirals. The apoptotic activation of caspases along pregnancy is emphasized in HIV pregnancies promoted by nucleoside analogues. However, we could not demonstrate direct mitochondrial or apoptotic implication in adverse obstetric outcome probably because of the reduced sample size.

A 66-year-old woman with the diagnosis of late-onset Pompe disease, receiving enzyme replacement therapy for the past 3 years, presented with a tongue tumor (figure 1) of uncertain evolution over time. It was soft at palpation and in the MRI study, the tongue looked bright in T1 but also an intense localized fatty degeneration generating a pseudohypertrophy of the tongue could be seen (figure 2). In late-onset Pompe disease, skeletal muscle is the most affected tissue and bright tongue sign is well known in patients with Pompe disease,1,2 but a benign tumor composed of muscle lingual pseudohypertrophy is an unusual finding.

The aim of the present study was to explore whether polymyositis may be considered as an isolated, organ-specific disease or more suitably as a secondary or associated entity. A retrospective re-evaluation of all the muscle biopsies performed at the Hospital Clinic of Barcelona showing histopathological pattern of polymyositis from January 1997 to May 2012 was carried out. The medical records of the patients with the aforementioned pathological pattern were also reviewed. From 1.290 muscle biopsies performed during the period evaluated, 36 with polymyositis pattern were identified. At the time of muscle biopsy, polymyositis pattern was secondary or associated with other disease in 26 patients and was classified as isolated in the remaining ten patients. After pathological re-evaluation and long-term clinical follow-up, only one patient remained with this diagnosis. Overall, the main final diagnosis related to the initial polymyositis pattern was inflammatory myopathy associated with connective tissue disease. Several other associated conditions were also identified. Isolated polymyositis is highly uncommon. Ruling out potential associated or confusing entities, like inclusion body myositis, overlap syndromes, infections, and cancer, is mandatory.