Diagnosis of dermatomyositis and polymyositis: a study of 102 cases

Sarcoplasmic Myxovirus Resistance Protein A: A Study of Expression in Idiopathic Inflammatory Myopathy

Background

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of autoimmune diseases affecting primarily proximal muscles. Major subtypes include dermatomyositis, polymyositis, inclusion body myositis, immune-mediated necrotizing myopathy and antisynthetase syndrome. Overexpression of sarcoplasmic myxovirus-resistance protein A (MxA) has been observed in muscle biopsy specimens of dermatomyositis but is rarely seen in other subtypes of IIM and other myopathies.

Objective

We evaluate the expression of sarcoplasmic MxA and its diagnostic value in IIM and other myopathies.

Methods

One hundred and thirty-eight muscle biopsy specimens with the diagnosis of IIM and other myopathies from 2011 to 2020 were reviewed and stained for MxA by immunohistochemistry. The difference of the expression of MxA between IIM and other myopathies was analyzed by Fisher's exact test, and the sensitivity and specificity of MxA immunohistochemistry in the diagnosis of IIM were assessed.

Results

MxA protein was positive in 16/138 (11.6%) specimens. All 12 dermatomyositis specimens positive for MxA protein were positive in perifascicular area pattern. Only dermatomyositis specimens had a significantly higher percentage of positive sarcoplasmic MxA expression than specimens of other subtypes of IIM (p<0.001). Sarcoplasmic MxA expression for dermatomyositis diagnosis had a sensitivity of 46.15% (95% CI 26.59-66.63%) and a specificity of 94.44% (95% CI 81.34-99.32%) with the positive and negative likelihood ratio of 8.31 (95% CI 2.03-34.01) and 0.57 (95% CI 0.40-0.82), respectively.

Conclusion

The MxA immunohistochemistry is highly specific for dermatomyositis and should be added to a routine inflammatory panel of muscle biopsy. MxA expression should be cautiously interpreted to avoid pitfalls.

A systematic review and meta-analysis on the prevalence and clinical characteristics of dysphagia in patients with dermatomyositis

BACKGROUND

Dermatomyositis (DM) is a rare autoimmune disease characterized by distinctive skin rash, muscle inflammation with symmetrical and progressive muscle weakness, and elevated serum levels of muscle-associated enzymes. DM may affect skeletal muscles involved in swallowing, leading to dysphagia, which can negatively impact individual's physical and psychosocial well-being. Despite this, dysphagia in patients with DM remains poorly understood. This systematic review and meta-analysis aimed to evaluate the prevalence and clinical features of dysphagia in patients with DM and juvenile DM (JDM).

METHODS

Four electronic databases were systematically searched until September 2022. Studies with patients with DM or JDM and dysphagia were included. The pooled prevalence of all included studies was calculated, and the clinical characteristics of dysphagia were qualitatively analyzed.

KEY RESULTS

Thirty-nine studies with 3335 patients were included. The overall pooled prevalence of dysphagia was 32.3% (95% CI: 0.270, 0.373) in patients with DM and 37.7% (95% CI: -0.031, 0.785) in patients with JDM. Subgroup analyses revealed that Sweden had the highest prevalence (66.7% [95% CI: 0.289, 1.044]), whereas Tunisia had the lowest prevalence (14.3% [95% CI: -0.040, 0.326]). Moreover, South America had the highest prevalence (47.0% [95% CI: 0.401, 0.538]), whereas Africa had the lowest prevalence (14.3% [95% CI: -0.040, 0.326]). Dysphagia in patients with DM and JDM was characterized by both oropharyngeal and esophageal dysfunctions, with predominant difficulties in motility.

CONCLUSIONS & INFERENCES

Our findings showed that dysphagia affects one in three patients with DM or JDM. However, the documentation on the diagnosis and management of dysphagia in the literature is inadequate. Our results highlighted the need to use both clinical and instrumental assessments to evaluate swallowing function in this population.

Transcriptome analysis reveals the mechanisms of hepatic injury caused by long-term environmental exposure to atrazine in juvenile common carp (Cyprinus carpio L.)

Atrazine (ATZ) is the second most commonly used herbicide worldwide, resulting in the pollution of water bodies and affecting the economic benefits of aquaculture. ATZ is known to cause liver damage in the common carp, Cyprinus carpio L., one of the most widely cultivated fish in China, but the underlying mechanisms are poorly understood. In this study, juvenile common carp Cyprinus carpio L. were exposed to three different environmental levels (0.4, 0.8, and 1.2 μg/L) of ATZ for 12 weeks and changes in the liver transcriptomes between the high-dose group and the control group were analyzed. The data showed that different levels of ATZ exposure caused hepatotoxicity in juvenile carp, shown by biochemical parameters and histopathological changes. Comparative transcriptomics showed that high-dose ATZ exposure led to alterations in the expression of various lipid metabolism-related gene changes, including genes associated with metabolic pathways, fatty acid metabolism, and fatty acid elongation. Furthermore, a connection network analysis of the top 100 differentially expressed genes (DEGs) showed a variety of associations between high-dose ATZ-induced liver damage and the principal DEGs, indicating the complexity of hepatotoxicity induced by ATZ. In conclusion, the molecular mechanisms underlying ATZ-triggered hepatotoxicity in juvenile carp are primarily related to impaired lipid metabolism.

[Epidemiological profile of dermatomyositis and polymyositis: a study conducted in the Department of Rheumatology in Marrakech]

La dermatomyosite (DM) et la polymyosite (PM) sont des affections rares mais graves. Le but de ce travail est d'étudier, à travers la revue d'une série hospitalière, leur profil épidémiologique, clinique et évolutif. Il s´agit d´une étude rétrospective, conduite sur une période de 15 ans, entre janvier 2004 et décembre 2019. Ont été retenus les cas où le diagnostic était certain ou probable selon les critères de Bohan et Peter. Un total de 14 patients ont été inclus (8 DM et 6 PM), l´âge moyen était de de 48,7 ans. La sex-ratio était de 13F/1H. Les signes généraux existaient dans 71%. Le déficit moteur touchait les muscles des ceintures dans 71% des cas; 85,7% avaient des arthralgies et 14% des arthrites. L´érythème et l´œdème périorbitaire étaient les signes cutanés prédominants. Au bilan, la vitesse de sédimentation était accélérée chez tous les malades et les enzymes musculaires augmentées dans 80%. Les anticorps anti-nucléaires étaient positifs dans 63%. La biopsie musculaire a retrouvé une myosite inflammatoire dans 75%. L'atteinte cardiaque existait dans 14% des cas et pulmonaire dans 21%. Un cancer était associé dans 21,4% des cas. Tous les patients ont reçu une corticothérapie. L´évolution s´est faite vers l´amélioration dans 88%, avec une rechute chez 4 patientes. Dans notre contexte, la DM est plus fréquente que la PM, avec nette prédominance féminine. L'atteinte pulmonaire reste une complication lourde. L´association aux cancers semble fréquente d´où la nécessité d´un bilan systématique de néoplasie au moment du diagnostic et lors du suivi.

The Impact of Dysphagia in Myositis: A Systematic Review and Meta-Analysis

(1) Background: Dysphagia is a clinical hallmark and part of the current American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) diagnostic criteria for idiopathic inflammatory myopathy (IIM). However, the data on dysphagia in IIM are heterogenous and partly conflicting. The aim of this study was to conduct a systematic review on epidemiology, pathophysiology, outcome and therapy and a meta-analysis on the prevalence of dysphagia in IIM. (2) Methods: Medline was systematically searched for all relevant articles. A random effect model was chosen to estimate the pooled prevalence of dysphagia in the overall cohort of patients with IIM and in different subgroups. (3) Results: 234 studies were included in the review and 116 (10,382 subjects) in the meta-analysis. Dysphagia can occur as initial or sole symptom. The overall pooled prevalence estimate in IIM was 36% and with 56% particularly high in inclusion body myositis. The prevalence estimate was significantly higher in patients with cancer-associated myositis and with NXP2 autoantibodies. Dysphagia is caused by inflammatory involvement of the swallowing muscles, which can lead to reduced pharyngeal contractility, cricopharyngeal dysfunction, reduced laryngeal elevation and hypomotility of the esophagus. Swallowing disorders not only impair the quality of life but can lead to serious complications such as aspiration pneumonia, thus increasing mortality. Beneficial treatment approaches reported include immunomodulatory therapy, the treatment of associated malignant diseases or interventional procedures targeting the cricopharyngeal muscle such as myotomy, dilatation or botulinum toxin injections. (4) Conclusion: Dysphagia should be included as a therapeutic target, especially in the outlined high-risk groups.

Myalgia in myositis and myopathies

Myalgia is a common symptom of various neuromuscular disorders: myalgia occurs in metabolic muscle diseases, inflammatory muscle diseases, dystrophic myopathies and myotonic muscle disorders. Myalgia leads to a significantly reduced quality of life. Other muscular symptoms that are present along with myalgia often provide the clue towards a diagnosis and include weakness, cramps and myotonia as well as the type of pain. In addition, extramuscular symptoms like an erythema in dermatomyositis can lead to the correct diagnosis. Basic diagnostic workup includes a detailed medical history, full neurologic assessment, laboratory tests, EMG and nerve conduction studies. Muscle imaging, genetic testing and muscle biopsy may be required to make a diagnosis. Whenever possible, treatment should aim to improve or correct the underlying cause for myalgia such as inflammation or hypothyroidism. Symptomatic therapy includes different avenues: Myotonia can be treated with mexiletine. Carbamazepine or phenytoin can be used in myotonic syndromes, particularly with muscle cramps. Pregabalin, gabapentin, or amitriptyline can be tried in conditions with myalgic pain. This review summarizes the symptoms, diagnostic strategies, and therapeutic approach in neuromuscular disorders that present with myalgia.

Clinical spectrums and outcomes of necrotizing autoimmune myopathy versus other idiopathic inflammatory myopathies: a multicenter case-control study

OBJECTIVE

To investigate the clinical characteristics, laboratory features, and treatment outcomes of Thai patients compared between those with necrotizing autoimmune myopathy (NAM) and those with other idiopathic inflammatory myopathies (IIMs) or non-NAM.

METHODS

This multicenter case-control study included patients aged ≥ 18 years who were diagnosed with IIMs by muscle pathology, and who had relevant clinical and laboratory data, including muscle enzymes, from at least 3 follow-up visits during a 1-year period. Baseline clinical and laboratory data were recorded. Serum myositis-specific autoantibodies (MSAs) were obtained on the date of recruitment.

RESULTS

Of the 70 included patients, 67% had NAM, and 33% had non-NAM. The mean age of patients was 50.5 ± 15.9 years, 67% were female, and the median duration of symptoms was 2 months (IQR, 1-4). History of cancer was significantly higher in non-NAM (21.7% vs. 2.1%, p = 0.01). Gottron's papules were significantly more prevalent in non-NAM (21.7% vs. 4.3%, p = 0.04). Non-NAM had a higher prevalence of anti-Mi-2a (17.4% vs. 2.1%, p = 0.04) and Mi-2b (17.4% vs. 0.0%, p = 0.01); however, the presence of other MSAs, including anti-HMGCR and anti-SRP, was similar between groups. Improvement in motor power and treatment intensification with glucocorticoid and/or immunosuppressive agents 3 times throughout the follow-up period was similar between groups (NAM 46.8% vs. non-NAM 34.8%, p = 0.34).

CONCLUSION

NAM is indistinguishable from non-NAM by clinical manifestations, serology, or laboratory findings, except that pathognomonic skin sign of Gottron's papules and anti-Mi2 are suggestive of dermatomyositis. The integration of clinical, serological, and pathological data is essential for making a diagnosis of NAM.Key Points• NAM is indistinguishable from non-NAM by clinical manifestations, serology, or laboratory findings.• The integration of clinical, serological, and pathological data is essential for making a diagnosis of NAM.

To biopsy or not to biopsy: evaluation of a large German cohort of patients with abnormal liver tests of unknown etiology

BACKGROUND AND AIMS

Despite increasingly sensitive and accurate blood tests to detect liver disease, liver biopsy remains very useful in patients with atypical clinical features and abnormal liver tests of unknown etiology. The aim was to determine those elevated laboratory liver parameters that cause the clinician to order a biopsy, and whether laboratory tests are associated with pathological findings on histology.

METHODS

504 patients with unclear hepatopathy, admitted to the outpatient clinic of a university hospital between 2007 and 2010, were analyzed with respect to laboratory results, clinical data, and the results of liver biopsies.

RESULTS

Aspartate aminotransferase (AST) and glutamate dehydrogenase (GLDH) levels above the normal range significantly increased the likelihood of recommending a liver biopsy by 81% [OR with 95% CI 1.81 (1.21-2.71), p = 0.004] and 159% [OR with 95% CI 2.59 (1.70-3.93), p < 0.001], respectively. AST values above normal were associated with fibrosis (63 vs. 40% for normal AST, p = 0.010). Elevated ferritin levels pointed to a higher incidence of steatosis (48 vs. 10% for normal ferritin, p < 0.001) and inflammation (87 vs. 62% for normal ferritin, p = 0.004).

CONCLUSIONS

Our results indicate that elevated AST and GLDH were associated with a greater likelihood of recommending liver biopsy. Elevated AST and ferritin levels were associated with steatosis, inflammation and fibrosis on liver biopsies. Thus, AST and ferritin may be useful non-invasive predictors of liver pathology in patients with unclear hepatopathy.

Dermatomyositis: analysis of 109 patients surveyed at the Hospital das Clínicas (HCFMUSP), São Paulo, Brazil

BACKGROUND

Dermatomyositis affects striated muscles, skin and other organs.

OBJECTIVE

To characterize the disease from January 1992 to December 2002, assessing its classification, cutaneous and systemic manifestations, and also laboratory results, therapeutic and prognostic findings compared to those in the literature.

METHODS

Data were obtained from medical records of 109 patients who were classified into five groups: 23 juvenile dermatomyositis; 59 primary idiopathic dermatomyositis; 6 amyopathic dermatomyositis; 7 dermatomyositis associated with neoplasms and 14 dermatomyositis associated with other connective tissue diseases.

RESULTS

Sixty patients were classified as "definite" diagnosis; 33 as "possible"; four as "probable" and 12 and as amyopathic. The average age at diagnosis was 36 years. Cutaneous manifestations occurred in all patients; the most frequent symptom was loss of proximal muscle strength; the most common pulmonary disorder was interstitial lung disease, and gastritis was the most prevalent digestive manifestation. Tumors were documented in 6.42% of cases. Lactate dehydrogenase was the muscle enzyme most frequently elevated in the majority of cases. Skin biopsies were performed in 68 patients; muscle biopsies in 53; and electroneuromyographies in 58 patients. The most commonly used treatment was corticotherapy and the mortality rate was 14.7%.

CONCLUSION

in this sample, the disease appeared in younger individuals, was more frequent in women and the association with cancer was small.

Upper limit of normal for alanine aminotransferase: quo vadis?

Several studies suggest that a substantial number of patients with normal serum alanine aminotransferase (ALT) levels, defined by current thresholds, have ongoing hepatic necro-inflammation and fibrosis, and are at risk of liver disease progression. A major problem lies in the definition of normality. The current upper limit of normal (ULN) for ALT was established in the 1980s when reference populations were likely to include many persons with hepatitis C virus infection and nonalcoholic fatty liver disease. Because ALT may be influenced, not only by liver disease, but also by other medical conditions, changing lifestyle factors and demographic determinants, the current ALT ULN threshold has recently been challenged. This review not only highlights current evidence on why and how ALT ULN should be redefined, but also discusses the current concerns about updating the ULN threshold for ALT.

Clinical, electrophysiologic, and histopathologic profile, and outcome in idiopathic inflammatory myositis: An analysis of 68 cases

Objectives:

To study the electroclinical and histopathologic profile of idiopathic inflammatory myositis (IIM) with reference to prognosis and survival rate.

Materials and Methods:

Diagnosis of IIM was based on the Bohan and Peter criteria. Patients who improved and those whose condition worsened or who expired due to IIM per se at last follow-up were classified to have favorable and poor outcomes, respectively. Fisher’s exact test was used for univariate analysis of prognostic factors.

Results:

The study cohort consisted of consecutive 68 patients with IIM. The mean age at diagnosis was 36.5 years and females constituted 71%. Of these patients, 62% had definite IIM, 49% had polymyositis, 20% had dermatomyositis, and 29% had overlap syndrome. The mean follow-up period was 5.4 years. Prednisolone alone was used in 55 (80%), and azathioprine (1–3 mg/kg/day) alone in 12 (17.6%) as the initial treatment. Relapse of IIM with drug withdrawal was seen in 15 patients (22%); 70% had favorable outcome and 16% had expired. The treatment delay of ≤6 months (P = 0.001), absence of cardiac or lung involvement (P < 0.001), and positive biopsy (P = 0.033) were predictive of a favorable prognosis in the univariate analysis. In multivariate analysis, only the duration of illness of ≤6 months (P = 0.008) and the absence of cardiac or lung involvement (P = 0.001) predicted the favorable outcome at last follow-up. Cumulative survival rate was 95% at 1 year, 86% at the 5th year, and 80% at the 10th year.

Conclusions:

Approximately, two-thirds of the patients showed good electroclinical and histopathologic correlations and an equal number improved with treatment. The treatment delay (≥6 months), presence of cardiac or pulmonary involvements, and negative muscle biopsy are bad prognostic factors.

Idiopathic inflammatory myopathies in childhood: a brief review of 27 cases

The most common idiopathic inflammatory myopathies in children include juvenile dermatomyositis, juvenile polymyositis, and myositis associated with another autoimmune disease (overlap myositis). Idiopathic inflammatory myopathies manifest different characteristics affecting children. Only a few investigations of childhood idiopathic inflammatory myopathies were reported, involving 27 patients. In addition, clinical findings, serum muscular enzyme levels, results of electromyography studies, muscle biopsy features, and treatment responses were studied. Seventeen female and 10 male were classified as exhibiting juvenile dermatomyositis (n = 19), juvenile polymyositis (n = 6), or overlap myositis (n = 2). Overlap myositis was associated with systemic sclerosis and systemic erythematous lupus. The mean age at onset was 6.1 years for juvenile dermatomyositis, 4.9 years for juvenile polymyositis, and 8.5 years for overlap myositis. The most common signs included proximal weakness and myalgia. The serum creatine kinase level was increased in 48.2% of patients. An electromyography study revealed myopathic features in 85% of patients. Muscle biopsies led to observations of inflammatory infiltrates with preferential perivascular involvement in the juvenile dermatomyositis group, and endomysial involvement in the juvenile polymyositis group. Fiber atrophy was predominantly perifascicular in the juvenile dermatomyositis group. Treatment with prednisone improved the findings in 81.5% of children.

Higher proportion of fast-twitch (type II) muscle fibres in idiopathic inflammatory myopathies - evident in chronic but not in untreated newly diagnosed patients

OBJECTIVE

Polymyositis and dermatomyositis are idiopathic, inflammatory myopathies characterized by proximal muscle fatigue. Conventional immunosuppressive treatment gives a variable response. Biopsies from chronic patients display a low proportion type I and a high proportion of type II muscle fibres. This raised a suspicion that the low proportion of type I fibres might play a role in the muscle fatigue.

AIM

To investigate whether the muscle fibre attributes evident in chronic myositis are characteristic for the polymyositis and dermatomyosistis diseases themselves.

METHODS

Muscle biopsies were obtained from thigh muscle from untreated patients (n = 18), treated responders (n = 14) and non-responders (n = 6) and from healthy controls (n = 11), respectively. For clinical evaluations, creatine kinase, functional index of myositis and cumulative dose of cortisone were established.

RESULTS

  Chronic patients had a lower proportion of type I fibres and a higher proportion of type II fibres compared to untreated myositis patients and healthy controls. Fibre cross-sectional area (CSA) did not differ between patients and healthy individuals but all women had a 20% smaller type II fibre CSA compared to men.

CONCLUSIONS

Untreated polymyositis and dermatomyositis patients and healthy controls have a different fibre type composition than chronic polymyositis and dermatomyositis patients. Fibre CSA did not differ between healthy controls or any of the patient groups. A low proportion of oxidative muscle fibres can therefore be excluded as a contributing factor causing muscle fatigue at disease onset and the gender difference should be taken into consideration when evaluating fibre CSA in myositis.

[Polymyositis and dermatomyositis in adults. Tunisian multicentre study]

INTRODUCTION

To study the clinical features and the outcome of polymyositis (PM) and dermatomyositis (DM) in Tunisia.

METHODS

Retrospective multicentre study conducted by the Tunisian Society of Internal Medicine. Adult patients with confirmed and probable PM and DM, according to the Bohan and Peter's criteria, were included in the study and followed-up between 1987 and 2005.

RESULTS

Twenty cases of PM and 50 cases of DM were included. Female/male sex-ratio was 2.5. The mean age at diagnosis was 40.7 years. Muscle weakness concerned girdle muscles in 94.3% and pharyngeal muscles in 42.8% of the patients. Interstitial lung disease and heart involvement occurred respectively in 35.7 and 20%. Eyelid erythema, peri-ungual erythema and Gottron's sign occurred in respectively 86, 50 and 36% of the cases of DM. Malignant disease was found in 12.8% of the patients (mainly gynecological and nasopharyngeal cancers). All patients received high dose corticosteroids with additional immunosuppressive drugs in 40% of the cases. The outcome was stabilization or partial improvement in 71.5% of the cases. Death occurred in 20% and was caused by respiratory failure, sepsis and cardiac failure.

CONCLUSION

The particularities of PM and DM in Tunisia are the preponderance of DM, early onset of the disease and high frequency of the nasopharyngeal cancer.

Juvenile dermatomyositis: clinical, laboratorial, histological, therapeutical and evolutive parameters of 35 patients

This study was based on a prospective and a retrospective analysis of 35 patients who met Bohan and Peter criteria for juvenile dermatomyositis diagnosis. The mean follow-up time was three years ten months. Calcinosis was present in five (14.28 %) patients, cutaneous ulcers in four (11.42%), and systemic involvement in nine (27.71%) patients. All patients presented alterations in the serum levels of muscle enzymes, and all of them were submitted to muscle biopsy as a diagnostic procedure. Nine (25.71%) patients received corticotherapy prior to and 26 (74.28%) after the muscle biopsy. Chloroquine, methotrexate, cyclosporine, cyclophosphamide and intravenous immunoglobulin were used in patients with poor response to corticotherapy. Continuation of cutaneous manifestations was observed in 4 (11.43%) patients, laboratorial activity in 1 (2.85%), cutaneous and laboratorial activities in 3 (8.57%). Ten (28.57%) patients were out of activity, and 17 (48.57%) in remission at study end-point, on March 2002. Two (5.71%) patients died.

Polymyositis: clinical investigation in two sisters

We present an investigation of a case of polymyositis affecting two sisters of one same parenthood. Their cases have been documented for almost two decades, being investigated by means of a diagnostic protocol which combined clinical findings as well as laboratorial, histopathological and image tests. In both cases, clinical manifestations started in childhood, without signs of involvement of the central and peripheral nervous system. Both patients proved to respond to a therapeutics based on corticosteroids. The degree of relatedness between their parents corroborate the notion that genetic factors may contribute to the development of the disease.