Polymyositis is a rare and favourable outcome subtype of idiopathic inflammatory myopathy in Chinese patients.

OBJECTIVES: To investigate the prevalence and characteristics of typical polymyositis (PM) in Chinese patients with idiopathic inflammatory myopathy (IIM). METHODS: Patients diagnosed with IIM according to the 2017 EULAR/ACR criteria were included. Serological aspects including myositis-specific antibodies (MSA) and pathological data were re-evaluated. The diagnosis of typical PM was strictly done using the pathological criteria, while excluding other IIM subtypes such as dermatomyositis (DM), immune-mediated necrotising myopathies (IMNM), anti-synthetase syndrome (ASS), and sporadic inclusion body myositis (sIBM), based on their respective diagnostic criteria. RESULTS: A total of 544 IIM patients with muscle biopsy were involved, and 129 of them were diagnosed with initial PM according to the 2017 EULAR/ACR criteria. Only 6 (1.1%, 6/544) patients met the strict definition of typical PM after re-evaluation. Patients with typical PM were MSA-negative (100% vs. 35.7%, p=0.003) and had CD8+ T cells surrounding or invading non-necrotic muscle fibres in muscle biopsies (100% vs. 7.8%, p<0.001) compared to the initially diagnosed PM patients. All typical PM patients achieved clinical remission at the second-year follow-up. Typical PM patients had a favourable prognosis compared to MSA-negative IMNM and unspecific myositis patients. CONCLUSIONS: Strictly defined typical PM is a rare clinical subtype in Chinese IIM patients. Typical PM patients with classical pathology were MSA-negative and responded well to treatment and had a favourable prognosis. It is crucial for clinicians to combine clinical, serological, and pathological features to properly distinguish PM from other IIM subtypes.

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis.

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia.

OBJECTIVE: To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population. METHODS: Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates. RESULTS: The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM. CONCLUSION: Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

Burkholderia-associated polymyositis.

A diagnosis of polymyositis can readily be made when there is a typical history of proximal muscle weakness together with clinical findings, and there is corroboratory evidence in the form of elevated creatine kinase lactate dehydrogenase, aldolase, and serum glutamic-oxaloacetic transaminase (aspartate aminotransferase). A muscle biopsy usually helps in making the confirmatory diagnosis. A female in her 50s presented with non-healing multiple deep necrotic ulcers with muscle weakness. The initial possibility of vasculitis ulcers remained. Later, this proved to be a case of polymyositis with mildly elevated creatine kinase (which is usually not the case), atypical skin manifestations (usually there is no skin involvement), and negative extended myositis specific antibody panel with the growth of Burkholderia cepacia (perhaps the triggering factor). Hence, polymyositis can present with a myriad of atypical findings. Thus, thorough clinical examination and an integrated approach are necessary for early identification and treatment of the disease.

Involvement of YKL-40-positive macrophages commonly identified in polymyositis and dermatomyositis in the pathogenesis of myositis: a retrospective study.

YKL-40 is implicated in inflammation and tissue repair, but no reports have investigated its involvement in myositis in polymyositis (PM) and dermatomyositis (DM). Therefore, we aimed to investigate the relationship between YKL-40 and PM/DM. We retrospectively enrolled 35 patients diagnosed with PM/DM along with 26 healthy controls (HCs). Both PM and DM were diagnosed according to Bohan and Peter's criteria. Serum YKL-40 levels were measured, age-corrected to YKL-40 percentile values, and compared to HCs. Patients with myositis without interstitial lung disease were also enrolled and compared to HCs. Immunofluorescence staining was performed to identify YKL-40-positive inflammatory cells in muscle biopsy samples from two patients each with PM and DM. Age-corrected serum YKL-40 levels were significantly higher in patients with PM/DM compared to HCs with and without lung disease; however, these levels decreased significantly after treatment. Immunohistochemical analysis showed infiltration of YKL-40-positive inflammatory cells into the intramuscular sheath and perimuscular membrane. Immunofluorescence staining showed CD68 expression in YKL-40-positive inflammatory cells, suggesting that these cells were macrophages. To the best of our knowledge, this is the first study to demonstrate that YKL-40-positive macrophages are present in PM and DM, indicating that YKL-40 may be involved in PM/DM.

Pompe disease misdiagnosed as polymyositis.

Late-onset Pompe disease manifests predominantly in the proximal lower limbs and may be mistaken for an inflammatory myopathy. A 46-year-old man with acromegaly had an 8-year history of progressive weakness. His myopathy was initially attributed to the acromegaly, but severe progression prompted a muscle biopsy, which suggested an inflammatory myopathy. However, his weakness progressed despite treatment for polymyositis. His muscle ultrasound scan pattern was more suggestive of Pompe disease than polymyositis, and Pompe disease was confirmed by genetic and enzymatic testing. Patients with apparent polymyositis, which persists despite treatment, require reconsideration of the diagnosis, with particular attention to treatable genetic causes.

The spectrum of idiopathic inflammatory myopathies in Western Australia: epidemiological characteristics and mortality over time.

To determine long term overall and subgroup specific incidence rates and associated mortality for idiopathic inflammatory myopathies (IIM) in a population wide study. We included patients hospitalised between 1980 and 2015 with incident IIM as defined by relevant diagnostic codes for dermatomyositis (DM) polymyositis (PM), inclusion body myositis (IBM), other IIM and overlap myositis (OM) in the Western Australia Health Hospital Morbidity Data Collection (n = 846). Trends over time for annual incidence rate per million population (AIR) were analysed by least square regression and Kaplan-Meier survival and mortality rates (MR)/100 person years compared with a matched control group (n = 3681). The averaged AIR for all IIM was 19 (CI 10.4-27.5) and stable over time with point prevalence reaching 205.3 (CI 185.6-226.6) per million in 2015. Over time, the AIR for DM 5.0 (CI 0.6-9.4) and IBM 3.3 (CI 0.7-9.6) was stable, while AIR decreased for PM (p < 0.01) and increased for other IIM (p < 0.01) and OM (p < 0.01). IBM patients were eldest at diagnosis (68 years, CI 59-77) with male preponderance in IBM (53.4%) and other IIM (55.8%) groups. Crude mortality (54.5 vs 41.3%), MR ratio (6.65 vs 5.91) and 5 (65.8% vs 71.6%) and 10-year (52.5% vs 58.7%) survival were all worse for IIM patients (all p < 0.05). IBM patients had highest MR (10.1; CI 8.38-12.14) and lowest 10-year survival (39.2%). While cardiovascular disease and cancer were predominant causes of death, they were proportionally lower in IIM patients, where respiratory and rheumatic disease were more frequent causes of death. While the overall incidence of IIM in WA was stable over 35 years, the spectrum of IIM has changed significantly with increases especially in other IIM and OM. The overall prognosis with IIM remains guarded with 10-year survival just over 50%.

Characteristics and risk of interstitial lung disease in dermatomyositis and polymyositis: a retrospective cohort study in Japan.

Dermatomyositis and polymyositis are rare, idiopathic inflammatory myopathies. Interstitial lung disease is one of the most common and potentially severe extra-muscular manifestations of dermatomyositis and polymyositis and is strongly linked to poor prognosis and early mortality. We aimed to characterise the demographic and clinical characteristics, incidence, and treatment of interstitial lung disease in patients with dermatomyositis or polymyositis. We conducted a retrospective cohort study using the Japan Medical Data Center healthcare claims database. Patients in the database with dermatomyositis (International Classification of Disease version 10 M33.0, M33.1, M33.9) or polymyositis (M33.2) from 01-Jan-2011 until 31-Dec-2019 were identified and followed-up for interstitial lung disease (J84.x) until death, dis-enrolment, or study end (31 December 2020). Cumulative risk curves compared interstitial lung disease risk in dermatomyositis versus polymyositis. Risk factors were evaluated by Cox proportional hazard models. There were 886 patients with dermatomyositis and 745 patients with polymyositis included in the cohort analysis. Mean (standard deviation) age at dermatomyositis/polymyositis diagnosis was 46.0 (16.0)/49.7 (13.3) years and 300 (34%)/104 (14%) developed interstitial lung disease during follow-up. The incidence rate of interstitial lung disease per 100 person-years was 18.42 (95% CI 16.42-20.59) for dermatomyositis and 5.39 (95% CI 4.43-6.50) for polymyositis. In the analysis adjusted for sex, age, and comorbidity score, the risk of interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis (hazard ratio 2.72, 95% CI 2.18-3.41). The rate diverged markedly between the groups in the first year after diagnosis. Risk factors for interstitial lung disease were older age in dermatomyositis, female sex and rheumatoid arthritis in polymyositis. Glucocorticoids with/without tacrolimus were the most common newly prescribed drugs after the interstitial lung disease diagnosis. In conclusion, the risk of developing interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis, and risk factors were different in the 2 patient groups.

The Prevalence of Dementia among Dermatomyositis and Polymyositis Patients: A Retrospective Cohort Study.

BACKGROUND: Polymyositis (PM) and dermatomyositis (DM) are inflammatory mediated myopathies characterized by progressive symmetric proximal muscle weakness and associated with extra-muscular involvement. Central nervous system complications are rarely reported with these diseases. OBJECTIVES: To investigate the association between dementia and PM/DM. METHODS: A retrospective cohort study was conducted using a database from Clalit Health Care, the largest health maintenance organization in Israel. Patients with a first recorded diagnosis of PM/DM were included and were compared with age- and sex-matched controls by a ratio of 1:5. The prevalence of dementia among PM/DM patients compared to controls was assessed using a univariate and a multivariable model. Binary logistic regression analysis was conducted to assess the association of different factors with dementia within the PM/DM cohort. RESULTS: The study included 2085 PM/DM cases (17.0%) and 10,193 age- and sex-matched controls (83.0%). During the follow-up time, 36 PM/DM patients were diagnosed with dementia compared to 160 controls, with a univariate hazard ratio (HR) of 1.10 (95% confidence interval [95%CI] 0.77-1.58). Within the PM/DM cohort, significant predictors for the development of dementia included increased age at diagnosis (5 years increment; OR 1.86, 95%CI 1.57-2.21, P < 0.001) and treatment with glucocorticoids (OR 5.40, 95%CI 1.67-17.67, P = 0.005). CONCLUSIONS: In our cohort, inflammatory myopathies were not associated with dementia. Age and treatment with glucocorticoids were associated with dementia. If dementia is diagnosed in patients with inflammatory myopathies, other systemic causes should be investigated.

Pulmonary hypertension, nephrotic syndrome, and polymyositis due to hepatitis C virus infection: A case report.

BACKGROUND: Hepatitis C infection not only damages the liver but also often accompanies many extrahepatic manifestations. Incidences of pulmonary hypertension (PH) caused by hepatitis C are rare, and incidences of concurrent nephrotic syndrome and polymyositis are even rarer. CASE SUMMARY: Herein we describe the case of a 57-year-old woman who was admitted to our department for intermittent chest tightness upon exertion for 5 years, aggravated with dyspnea for 10 d. After relevant examinations she was diagnosed with PH, nephrotic syndrome, and polymyositis due to chronic hepatitis C infection. A multi-disciplinary recommendation was that the patient should be treated with sildenafil and macitentan in combination and methylprednisolone. During treatment autoimmune symptoms, liver function, hepatitis C RNA levels, and cardiac parameters of right heart catheterization were monitored closely. The patient showed significant improvement in 6-min walking distance from 100 to 300 m at 3-mo follow-up and pulmonary artery pressure drops to 50 mmHg. Long-term follow-up is needed to confirm further efficacy and safety. CONCLUSION: Increasing evidence supports a relationship between hepatitis C infection and diverse extrahepatic manifestations, but it is very rare to have PH, nephrotic syndrome, and polymyositis in a single patient. We conducted a literature review on the management of several specific extrahepatic manifestations of hepatitis C.

Polymyositis and dermatomyositis biomarkers.

Polymyositis (PM) and dermatomyositis (DM) are the two subtypes of idiopathic inflammatory myositis and are characterized as symmetrical progressive muscle weakness in the proximal extremities. PM/DM affect multiple organs and systems, including the cardiovascular, respiratory and digestive tract systems. An in-depth understanding of PM/DM biomarkers will facilitate development of simple and accurate strategies for diagnosis, treatment, and prognosis prediction. This review summarized the classic biomarkers of PM/DM, including anti-aminoacyl tRNA synthetases (ARS) antibody, anti-Mi-2 antibody, anti-melanoma differentiation-associated gene 5 (MDA5) antibody, anti-transcription intermediary factor 1-γ (TIF1-γ) antibody, anti-nuclear matrix protein 2 (NXP2) antibody, among others. Among them, anti-aminoacyl tRNA synthetases antibody is the most classic. In addition, many potential novel biomarkers were also discussed in this review, including anti-HSC70 antibody, YKL-40, interferons, myxovirus resistance protein 2, regenerating islet-derived protein 3-α, interleukin (IL)-17, IL-35, microRNA (miR)-1 and so on. Among the biomarkers of PM/DM described in this review, classic biomarkers have become the mainstream biomarkers to assist clinicians in diagnosis due to their early discovery, in-depth research, and widespread application. The novel biomarkers also have potential and broad research prospects, which will make immeasurable contributions to exploring biomarker-based classification standards and expanding their application value.

The rise and fall of troponin in a patient with polymyositis.

Troponins are an excellent sensitive marker for myocardial ischaemic damage. However, there are several non-ischaemic cardiac and non-cardiac reasons for troponin elevation. Many cases of troponin T elevation and some troponin I cases have been reported in the literature due to inflammatory muscle disease. Here, we report a woman in her 50s who initially presents with fatigue and weakness, and is found to have elevated troponin T. The patient was appropriately worked up for cardiac causes with ECG and echocardiogram. She had positive antinuclear antibodies, antineutrophil cytoplasmic antibody and myositis panel. The elevation of troponins was attributed to polymyositis and treated with methotrexate and prednisone with recovery of patient's symptoms. This article emphasises the struggle of diagnosis in a patient with no reported medical history, having low to moderate risk of silent myocardial infarction.

Tim-3, PD-1, CD244 and Foxp3 Positive T Cells' Relation to the Prognosis of Dermatomyositis and Polymyositis Patients.

OBJECTIVE: To explore the frequency of circulating CD4+ T cells expressing PD-1+, TIM-3+ in polymyositis (PM) and dermatomyositis (DM) patients and its correlation with inflammatory factors, CD244+ and FOXP3+ T cell subtypes and prognosis. STUDY DESIGN: Observational study. Place and Duration of the Study: Ganzhou people's Hospital, Ganzhou, Jiangxi, China, from July 2019 to June 2021. METHODOLOGY: PM and DM patients were treated according to the institution's guidelines and followed up for 2 years. Fifty healthy volunteers were enrolled as controls. Serum interleukin (IL)-6, C-reactive protein (CRP), IL-17, and tumour necrosis factor α (TNF-α) levels were detected by enzyme-linked immunosorbent assay (ELISA). TIM-3+, PD-1+, CD244+, and FOXP3+ expressions were measured using flow cytometry. Inability to live normally, recurrence or death was defined as poor prognosis. RESULTS: The ESR, ALT, AST, LDH and ferritin concentration in PM/DM patients were remarkably elevated than that in healthy volunteers. The frequencies of PD-1+, TIM-3+, CD244+, and FOXP3+ were all remarkably enhanced in PM/DM patients compared with the healthy volunteers. The frequencies of PD-1+, TIM-3+, FOXP3+, and TIM-3+/PD-1+ T cells were significantly elevated in the poor prognosis group compared with the good prognosis group. The frequency of CD4+TIM-3+PD-1+ had satisfactory diagnostic value for PM/DM patients with bad prognoses. IL-17, TIM-3+, PD-1+and TIM-3+ PD-1+ were the risk factors for PM/DM patients with bad outcomes. CONCLUSION: The frequency of circulating CD4+ T cells expressing TIM-3+PD-1+ could be used to predict the prognosis of PM/DM patients. KEY WORDS: Tim-3, PD-1, Dermatomyositis, Polymyositis, Inflammatory.

Metabolic profiling of patients with different idiopathic inflammatory myopathy subtypes reveals potential biomarkers in plasma.

Idiopathic inflammatory myopathy (IIM) are heterogeneous autoimmune diseases that primarily affect the proximal muscles. IIM subtypes include dermatomyositis (DM), polymyositis (PM), and anti-synthetase syndrome (ASS). Metabolic disturbances may cause irreversible structural damage to muscle fibers in patients with IIM. However, the metabolite profile of patients with different IIM subtypes remains elusive. To investigate metabolic alterations and identify patients with different IIM subtypes, we comprehensively profiled plasma metabolomics of 46 DM, 13 PM, 12 ASS patients, and 30 healthy controls (HCs) using UHPLC-Q Exactive HF mass spectrometer. Multiple statistical analyses and random forest were used to discover differential metabolites and potential biomarkers. We found that tryptophan metabolism, phenylalanine and tyrosine metabolism, fatty acid biosynthesis, beta-oxidation of very long chain fatty acids, alpha-linolenic acid and linoleic acid metabolism, steroidogenesis, bile acid biosynthesis, purine metabolism, and caffeine metabolism are all enriched in the DM, PM, and ASS groups. We also found that different subtypes of IIM have their unique metabolic pathways. We constructed three models (five metabolites) to identify DM, PM, ASS from HC in the discovery and validation sets. Five to seven metabolites can distinguish DM from PM, DM from ASS, and PM from ASS. A panel of seven metabolites can identify anti-melanoma differentiation-associated gene 5 positive (MDA5 +) DM with high accuracy in the discovery and validation sets. Our results provide potential biomarkers for diagnosing different subtypes of IIM and a better understanding of the underlying mechanisms of IIM.

Dermatomyositis associated with thymoma: A case report and literature review.

Abstract: Thymoma can present with paraneoplastic-autoimmune neuro-muscular disorders, including polymyositis, dermatomyositis, and granulomatous myositis. Rarely, concomitant subclinical myasthenia gravis (MG) can be a diagnostic dilemma and cause deleterious outcomes regarding missed or delayed diagnosis. We report a Turkish patient presented with thymoma associated dermatomyositis and positive acetylcholine receptor antibody without evident MG clinic.

Long-term survival of patients with idiopathic inflammatory myopathies: anatomy of a single-centre cohort.

OBJECTIVES: We aimed to characterise clinical manifestations, disease course, treatment, and mortality of IIM patients. We have also attempted to identify predictors of mortality in IIM. METHODS: This was a retrospective single-centre study including IIM patients fulfilling the Bohan and Peter criteria. Patients were divided in 6 groups: adult-onset polymyositis (APM), adult-onset dermatomyositis (ADM), juvenile-onset dermatomyositis, 'overlap' myositis (OM), cancer-associated myositis, and antisynthetase syndrome. Sociodemographic, clinical and immunological features, treatment, and causes of death were recorded. Survival analysis and predictors of mortality was performed using Kaplan-Meier and Cox proportional hazards regression. RESULTS: A total of 158 patients were included with a mean age at diagnosis of 40.8±15.6 years. Most patients were female (77.2%) and Caucasian (63.9%). The most frequent diagnoses were ADM (35.4%), OM (20.9%) and APM (24.7%), respectively. Most patients (74.1%) were treated with a combination of steroids and one-to-three immunosuppressive drugs. Interstitial lung disease, gastrointestinal and cardiac involvement affected 38.5%, 36.5% and 23.4% of the patients, respectively. The survival rates at 5, 10, 15, 20 and 25 years of follow-up were 89%, 74%, 67%, 62% and 43%, respectively. During a median follow-up of 13.6±10.2 years, 29.1% have died, infection being the most common cause (28.3%). Older age at diagnosis (HR1.053, 95% CI 1.027-1.080), cardiac involvement (HR 2.381, 95% CI 1.237-4.584), and infections (HR 2.360, 95% CI 1.194-4.661) were independent predictors of mortality. CONCLUSIONS: IIM is a rare disease with important systemic complications. Early diagnosis and aggressive treatment of cardiac involvement and infections could improve survival of these patients.

Edema localized to the lips as a novel manifestation of myositis.

Polymyositis (PM) and dermatomyositis (DM) are idiopathic inflammatory myopathies with presumed autoimmune pathogenesis, characterized by the features of proximal skeletal muscle weakness and evidence of muscle inflammation. Skin manifestations usually prompt earlier recognition and diagnosis of DM than PM, which has no rash. Associated delayed diagnosis and treatment in PM lead to worse outcomes. Therefore, an accumulation of case reports regarding initial symptoms suggestive of PM has been required to obtain an earlier diagnosis and better clinical outcomes in PM patients. We herein report a PM patient with an unusual presentation of edema restricted to the lips, which was clinically suggestive of granulomatous cheilitis but histologically verified as a manifestation of myositis. In this patient, no myositis-specific antibodies including anti-nuclear matrix protein 2 antibodies, were detected, and histological analysis on the muscle biopsy specimen revealed CD4-dominant lymphocyte infiltration but no C5b-9 deposition nor myxovirus resistance protein A expression. Further analysis with MRI (magnetic resonance imaging) scan of the lips showed increased signal intensity in the muscle layer on short TI inversion recovery images, and these suggest the potential of MRI as a useful tool for exploring the inflammatory site and the possibility of myositis in swollen lips. Thus, our report indicates the importance of suspecting myositis in the case of unusual edema restricted to the lips.

Overlap syndrome involving anti-OJ antibody-positive polymyositis, systemic lupus erythematosus and Sjögren's syndrome: A case report and literature review.

Anti-OJ antibody is relatively rarely detected in patients with the anti-synthetase syndrome, which is polymyositis (PM)/dermatomyositis (DM) with anti-aminoacyl transfer ribonucleic acid (RNA) synthetase antibodies. There have been few case reports of anti-OJ antibody-positive PM/DM complicated by other connective tissue disorders. Herein, we report the case of a 33-year-old woman who was admitted to our hospital with fever, muscle weakness, and dyspnoea on exertion. She was diagnosed with anti-OJ antibody-positive PM, overlapping systemic lupus erythematosus, and Sjögren's syndrome (SS). Her symptoms and clinical findings improved after treatment with prednisolone 1 mg/kg/day without immunosuppressive agents. This is the first case of overlap syndrome with anti-OJ antibody-positive PM, systemic lupus erythematosus, and Sjögren's syndrome.