-
Arthritis Care & Research Dec 2013To differentiate juvenile polymyositis (PM) and muscular dystrophy, both of which may present with chronic muscle weakness and inflammation.
OBJECTIVE
To differentiate juvenile polymyositis (PM) and muscular dystrophy, both of which may present with chronic muscle weakness and inflammation.
METHODS
We studied 39 patients with probable or definite juvenile PM and 9 patients with muscular dystrophies who were initially misdiagnosed as having juvenile PM. Differences in demographic, clinical, and laboratory results; outcomes; and treatment responses were evaluated by Fisher's exact and rank sum tests. Random forests classification analysis and logistic regression were performed to examine significant differences in multivariable models.
RESULTS
Clinical features and serum muscle enzyme levels were similar between juvenile PM and dystrophy patients, except 89% of dystrophy patients had muscle atrophy compared with 46% of juvenile PM patients. Dystrophy patients had a longer delay to diagnosis (median 12 versus 4 months) and were less frequently hospitalized than juvenile PM patients (22% versus 74%). No dystrophy patients, but 54% of juvenile PM patients, had a myositis autoantibody. Dystrophy patients more frequently had myopathic features on muscle biopsy, including diffuse variation of myofiber size, fiber hypertrophy, and myofiber fibrosis (44-100% versus 8-53%). Juvenile PM patients more frequently had complex repetitive discharges on electromyography and a complete response to treatment with prednisone or other immunosuppressive agents than dystrophy patients (44% versus 0%). Random forests analysis revealed that the most important features in distinguishing juvenile PM from dystrophies were myositis autoantibodies, clinical muscle atrophy, and myofiber size variation on biopsy. Logistic regression confirmed muscle atrophy, myofiber fibrosis, and hospitalization as significant predictors.
CONCLUSION
Muscular dystrophy can present similarly to juvenile PM. Selected clinical and laboratory features are helpful in combination in distinguishing these conditions.
Topics: Adolescent; Child; Child, Preschool; Diagnosis, Differential; Female; Humans; Infant; Male; Muscular Dystrophies; Polymyositis
PubMed: 23925923
DOI: 10.1002/acr.22088 -
Medicine Sep 2021The aim of this study was to evaluate the association between clinical phenotypes of dermatomyositis (DM) and polymyositis (PM) with myositis-specific antibodies (MSAs),...
The aim of this study was to evaluate the association between clinical phenotypes of dermatomyositis (DM) and polymyositis (PM) with myositis-specific antibodies (MSAs), and overlap diagnosis of systemic autoimmune diseases.This cross-sectional study was conducted on 67 patients with DM and 27 patients with PM recruited from a regional hospital in southern Taiwan. Clinical phenotypes of DM and PM were assessed and MSAs were measured using a commercial line blot assay. The association of clinical phenotypes of DM and PM with MSAs and overlap diagnosis of systemic autoimmune diseases was performed using univariate and multiple logistic regression analyses.Clinically, patients with DM and PM and overlap diagnosis of systemic sclerosis were associated with a higher risk of interstitial lung diseases (ILDs) (odds ratio [OR] = 6.73; P = .048), Raynaud phenomenon (OR = 7.30; P = .034), and malignancy (OR = 350.77; P = .013). The risk of malignancy was also associated with older age (OR 1.31; P = .012), and male patients were associated with a higher risk of fever. For MSAs, anti-aminoacyl-tRNA synthetase antibodies were associated with ILD, antinuclear antibody were associated with a lower risk of arthritis, anti-transcription intermediary factor 1-gamma antibodies were associated with milder symptoms of muscle weakness, anti-Ku antibodies were associated with overlap diagnosis of systemic lupus erythematosus, and anti-Ro52 antibodies were associated with the development of Raynaud phenomenon and Sjögren syndrome.MSAs and overlap diagnosis of systemic sclerosis were significantly associated with clinical phenotypes of DM and PM. Physicians should be vigilant for malignancy in older DM and PM patients with overlap diagnosis of systeic sclerosis. The possibility of developing ILD in patients with overlap diagnosis of systemic sclerosis or serum positivity of anti-aminoacyl-tRNA synthetase antibodies should be considered.
Topics: Adult; Aged; Autoantibodies; Biomarkers; Cross-Sectional Studies; Dermatomyositis; Female; Humans; Male; Middle Aged; Phenotype; Polymyositis; Taiwan
PubMed: 34664863
DOI: 10.1097/MD.0000000000027230 -
PloS One 2014To define potential factors that could predict concomitant neoplastic diseases in patients diagnosed with PM/DM, which could inform screening decisions. (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
To define potential factors that could predict concomitant neoplastic diseases in patients diagnosed with PM/DM, which could inform screening decisions.
METHODS
Two researchers independently reviewed articles from Pubmed (MEDLINE), EMBASE, Cochrane Plus Library and ISI Web of Knowledge with no restrictions on study design or language. Given that some of the studies combined PM and DM patients as research subjects while others included only DM patients, data were subjected to meta-analyses for all combined PM/DM studies and studies that included only DM patients to obtain informative results.
RESULTS
For PM/DM patients, the following factors are all associated with an increased risk of malignancy: older age, age greater than 45, male sex, dysphagia, cutaneous necrosis, cutaneous vasculitis, rapid onset of myostis (<4 weeks), elevated CK, higher ESR, higher CRP levels. Several factors were associated with lower-than-average risk, including the presence of ILD, arthritis/arthralgia, Raynaud's syndrome, or anti-Jo-1 antibody. For DM patients, results indicated an increased risk of malignancy with older age, male sex, the presence of cutaneous necrosis, elevated ESR (>35 mm/hr), higher CRP levels, or anti-p155 antibody. In addition, the presence of anti-ENA antibodies seem to be related to reduced risk of malignancy.
CONCLUSION
Awareness and implementation of early-stage cancer screening in PM/DM patients who have these identified factors--such as being older than 45, male sex, cutaneous necrosis, cutaneous vasculitis--are of crucial importance from public health and clinical perspectives and provide insight into the etiopathogenesis of CAM.
Topics: Age Factors; Dermatomyositis; Female; Humans; Male; Neoplasms; Polymyositis; Prognosis; Risk Factors; Sex Factors
PubMed: 24713868
DOI: 10.1371/journal.pone.0094128 -
The Journal of Rheumatology Jan 2021Patients with dermatomyositis (DM) and polymyositis (PM) have reduced muscle endurance.The aim of this study was to streamline the Functional Index-2 (FI-2) by...
OBJECTIVE
Patients with dermatomyositis (DM) and polymyositis (PM) have reduced muscle endurance.The aim of this study was to streamline the Functional Index-2 (FI-2) by developing the Functional Index-3 (FI-3) and to evaluate its measurement properties, content and construct validity, and intra- and interrater reliability.
METHODS
A dataset of the previously performed and validated FI-2 (n = 63) was analyzed for internal redundancy, floor, and ceiling effects. The content of the FI-2 was revised into the FI-3. Construct validity and intrarater reliability of FI-3 were tested on 43 DM and PM patients at 2 rheumatology centers. Interrater reliability was tested in 25 patients. The construct validity was compared with the Myositis Activities Profile (MAP), Health Assessment Questionnaire (HAQ), and Borg CR-10 using Spearman correlation coefficient.
RESULTS
Spearman correlation coefficients of 63 patients performing FI-3 revealed moderate to high correlations between shoulder flexion and hip flexion tasks and similar correlations with MAP and HAQ scores; there were lower correlations for neck flexion task. All FI-3 tasks had very low to moderate correlations with the Borg scale. Intraclass correlation coefficients (ICC) of FI-3 tasks for intrarater reliability (n = 25) were moderate to good (0.88-0.98). ICC of FI-3 tasks for interrater reliability (n = 17) were fair to good (range 0.83-0.96).
CONCLUSION
The FI-3 is an efficient and valid method for clinically assessing muscle endurance in DM and PM patients. FI-3 construct validity is supported by the significant correlations between functional tasks and the MAP, HAQ, and Borg CR-10 scores.
Topics: Dermatomyositis; Humans; Polymyositis; Range of Motion, Articular; Reproducibility of Results
PubMed: 32295854
DOI: 10.3899/jrheum.191374 -
Neurology India 2021Polymyositis is a group of muscle disease characterised by progressive muscle inflammation and predominantly muscle weakness. It usually presents subacutely with...
Polymyositis is a group of muscle disease characterised by progressive muscle inflammation and predominantly muscle weakness. It usually presents subacutely with proximal weakness and mild diffuse muscular pain. Some patients have atypical presentation like early respiratory difficulty, Motor neuron disease (MND), or isolated dysphagia which leads to delay in diagnosis and treatment. We present one such case.
Topics: Deglutition Disorders; Humans; Motor Neuron Disease; Muscle Weakness; Myositis; Polymyositis
PubMed: 34747820
DOI: 10.4103/0028-3886.329582 -
Scientific Reports Feb 2021Our study aimed to investigate the incidence, risk factors and time to occurrence of malignancy in patients with dermatomyositis (DM) and polymyositis (PM). The...
Our study aimed to investigate the incidence, risk factors and time to occurrence of malignancy in patients with dermatomyositis (DM) and polymyositis (PM). The electronic medical records of 1100 patients with DM and 1164 patients with PM were studied between January 2001 and May 2019. Malignancies after myositis were diagnosed in 61 (5.55%) patients with DM and 38 (3.26%) patients with PM. The cumulative incidence of malignancies in patients with DM were significantly higher than patients with PM (hazard ratio = 1.78, log-rank p = 0.004). Patients with DM had a greater risk of developing malignancy than those with PM at 40-59 years old (p = 0.01). Most malignancies occurred within 1 year after the initial diagnosis of DM (n = 35; 57.38%). Nasopharyngeal cancer (NPC) was the most common type of malignancy in patients with DM (22.95%), followed by lung, and breast cancers. In patients with PM, colorectal, lung and hepatic malignancies were the top three types of malignancy. The risk factors for malignancy included old age (≥ 45 years old) and low serum levels of creatine phosphokinase (CPK) for patients with DM and male sex and low serum levels of CPK for patients with PM. Low serum levels of CPK in patients with myositis with malignancy represented a low degree of muscle destruction/inflammation, which might be attributed to activation of the PD-L1 pathway by tumor cells, thus inducing T-cell dysfunction mediating immune responses in myofibers. A treatment and follow-up algorithm should explore the occurrence of malignancy in different tissues and organs and suggested annual follow-ups for at least 5.5 years to cover the 80% cumulative incidence of malignancy in patients with DM and PM.
Topics: Adult; Aged; Aged, 80 and over; Comorbidity; Dermatomyositis; Diagnosis, Differential; Female; Humans; Incidence; Male; Middle Aged; Polymyositis; Public Health Surveillance; Registries; Risk Assessment; Risk Factors; Taiwan; Young Adult
PubMed: 33633147
DOI: 10.1038/s41598-021-83729-5 -
Tomography (Ann Arbor, Mich.) Mar 2024(1) Background: The intravoxel incoherent motion (IVIM) model can provide information about both molecular diffusion and blood flow for the evaluation of skeletal muscle...
(1) Background: The intravoxel incoherent motion (IVIM) model can provide information about both molecular diffusion and blood flow for the evaluation of skeletal muscle inflammation. MRI-based fat quantification is advantageous for assessing fat infiltration in skeletal muscle. (2) Purpose: We aimed to quantitatively measure various parameters associated with IVIM diffusion-weighted imaging (DWI) and fat quantification in the muscles of patients with polymyositis and dermatomyositis using magnetic resonance imaging and to investigate the relationship between these parameters and electromyography (EMG) findings. (3) Material and methods: Data were retrospectively evaluated for 12 patients with polymyositis and dermatomyositis who underwent thigh MRI, including IVIM-DWI and fat quantification. The IVIM-derived parameters included the pure diffusion coefficient (D), pseudodiffusion coefficient (D*), and perfusion fraction (). Fat fraction values were assessed using the six-point Dixon technique. Needle EMG was performed within 9 days of the MRI. (4) Results: The values (19.02 ± 4.87%) in muscles with pathological spontaneous activity on EMG were significantly higher than those (14.60 ± 5.31) in muscles without pathological spontaneous activity ( < 0.027). There were no significant differences in D, D*, ADC, or fat fraction between muscles with and without pathologic spontaneous activity. Significant negative correlations were observed between fat fraction and amplitude ( = -0.402, < 0.015) and between fat fraction and duration ( = -0.360, < 0.031). (5) Conclusion: The current study demonstrates that IVIM-DWI and fat quantification using 3.0 T MRI may aid in predicting EMG findings in patients with polymyositis and dermatomyositis and promote the pathophysiological study of idiopathic inflammatory myopathies.
Topics: Humans; Electromyography; Dermatomyositis; Retrospective Studies; Diffusion Magnetic Resonance Imaging; Polymyositis; Myositis
PubMed: 38535771
DOI: 10.3390/tomography10030029 -
PloS One 2016Interstitial lung disease (ILD) is an extramuscular manifestation that results in increased morbidity and mortality from polymyositis (PM) and dermatomyositis (DM). The... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVES
Interstitial lung disease (ILD) is an extramuscular manifestation that results in increased morbidity and mortality from polymyositis (PM) and dermatomyositis (DM). The aim of this study was to systematically evaluate risk factors associated with the development of ILD in PM/DM.
METHODS
Observational studies were identified from searching PubMed, Medline, Embase, and the Cochrane Library. Pooled odds ratios (ORs) or standardized mean differences (SMDs) and corresponding 95% confidence intervals (CIs) were obtained for the relationships between risk factors and ILD in PM/DM using either fixed- or random-effects models, whichever were appropriate. Heterogeneity tests, sensitivity analyses, and publication bias assessments were also performed.
RESULTS
Twenty-three studies were selected for a meta-analysis that included 834 patients and 1245 control subjects. Risk factors that may have increased the risk of developing ILD in PM/DM patients included older age at diagnosis (SMD, 0.35; 95% CI, 0.18-0.52; P < 0.0001), arthritis/arthralgia (OR, 3.17; 95% CI, 1.99-5.04; P < 0.00001), fever (OR, 2.31; 95% CI, 1.42-3.76; P = 0.0007), presence of anti-Jo-1 antibodies (OR, 3.34; 95% CI, 2.16-5.16; P < 0.00001), elevated erythrocyte sedimentation rate (ESR; SMD, 0.48; 95% CI, 0.32-0.64; P < 0.00001), presence of anti-MDA5 antibodies (OR, 18.26; 95% CI, 9.66-34.51; P < 0.00001), and elevated C-reactive protein level (CRP; OR, 3.50; 95% CI, 1.48-8.28; P = 0.004). Meanwhile, malignancy (OR, 0.36; 95% CI, 0.18-0.72; P = 0.004) reduced the risk of developing ILD in PM/DM patients.
CONCLUSION
Our meta-analysis results suggest that the association between PM/DM and ILD may be due to such risk factors as older age at diagnosis, arthritis/arthralgia, fever, presence of anti-Jo-1 antibodies, elevated ESR, presence of anti-MDA5 antibodies, and elevated CRP level, while malignancy was associated with a reduced risk of developing ILD. Thus, these variables may be used to guide screening processes for ILD in patients with PM/DM.
Topics: Demography; Dermatomyositis; Female; Humans; Lung Diseases, Interstitial; Male; Polymyositis; Publication Bias; Risk Factors
PubMed: 27171228
DOI: 10.1371/journal.pone.0155381 -
Reumatismo Dec 2023Idiopathic immune myopathies (IIMs) are autoimmune diseases caused by immune-mediated muscle damage. The etiology remains unclear. Epidemiological and experimental...
Idiopathic immune myopathies (IIMs) are autoimmune diseases caused by immune-mediated muscle damage. The etiology remains unclear. Epidemiological and experimental studies, both in animals and humans, hint at viruses as major environmental factors able to trigger aberrant immune responses through many different mechanisms. However, only a few cases of either dermatomyositis or polymyositis following a specific viral infection have been reported in the literature. The objective of this study is to describe the clinical features and the treatment strategy of 2 cases of polymyositis developing shortly after chickenpox and mumps, respectively, and to review the existing literature on the topic. The clinical records of the 2 patients suspected to have developed inflammatory myositis following a viral infection were reviewed. Their clinical history, main laboratory findings, and treatment outcome are presented here. Moreover, a literature search was performed in the PubMed and MEDLINE databases to identify reports describing the association between viral infections and IIMs in patients aged ≥18. The 2 patients reported here developed polymyositis shortly after chickenpox and mumps, respectively, suggesting a causal role for viruses in triggering autoimmunity. Only a few reports published between 1990 and 2020 were found in the literature, possibly linking infections to myositis development. Intravenous immunoglobulin and rituximab were effective for the treatment of viral-triggered polymyositis.
Topics: Adult; Humans; Autoimmune Diseases; Chickenpox; Dermatomyositis; Mumps; Myositis; Polymyositis
PubMed: 38115780
DOI: 10.4081/reumatismo.2023.1562 -
Contrast Media & Molecular Imaging 2022This paper aims to investigate the clinical and laboratory test characteristics of patients with anti-MDA5 antibody-positive PM/DM by analyzing the clinical...
This paper aims to investigate the clinical and laboratory test characteristics of patients with anti-MDA5 antibody-positive PM/DM by analyzing the clinical characteristics, laboratory test results, and 1-year survival rate of patients with anti-MDA5 antibody-positive PM/DM in polymyositis (PM) and dermatomyositis (DM). To further investigate the impact of positive anti-MDA5 antibodies on the prognosis of PM/DM patients. According to the anti-MDA5 antibody test results, 18 cases with positive anti-MDA5 antibodies were in the positive group and 46 cases with negative anti-MDA5 antibodies were in the negative group. The clinical manifestations, laboratory tests, treatment protocols, and prognostic risk factors were collected for both groups. The chi-square test, Mann-Whitney method, Fisher test, -test, Kaplan-Meier method, and Log-rank test were used for statistical analysis. Anti-MDA5 antibody positivity was more common in patients with DM/CADM. With no statistically significant differences in age and sex ratio between the two groups, The differences in erythrocyte sedimentation rate (ESR), ferritin (Fer), and creatine kinase (CK) levels in the positive group were statistically significant compared with the negative group. Clinically, the positive group was more prone to arthralgia, skin rash, and interstitial pneumonia.
Topics: Autoantibodies; Dermatomyositis; Humans; Interferon-Induced Helicase, IFIH1; Lung Diseases, Interstitial; Polymyositis
PubMed: 35992549
DOI: 10.1155/2022/7102480