Peter Criteria Research Articles

Long Term Outcomes in Idiopathic Inflammatory Myositis: An Observational Epidemiologic Study over 15 Years.

We report a longitudinal observational cohort of idiopathic inflammatory myositis (IIM) focusing on the long-term clinical outcome and associated parameters. IIM patients were classified as per Bohan and Peter criteria. In those with ≥ 24 months of follow-up; the treatment response, functional outcomes, and damage at last follow-up were recorded. Complete clinical response and clinical remission as defined by Oddis et al., was used to define outcomes at last follow-up. The cohort consists of 175 patients, mean age 40.9 (+12.6) years, M:F 1:3.3; and the major subsets were dermatomyositis (44.6%), overlap myositis (25.7%), antisynthetase syndrome (6.3%), polymyositis (14.3%), and juvenile DM/OM (8.6%). Ninety-four patients have followed up for 24 months or more, with the median (IQR) of 65(35,100.7) months. Of them, 74.1% and 11.8% had complete and partial clinical responses respectively at the last follow-up. In our cohort 40.2% were off-steroids and 13.8% were in clinical remission at the last follow-up. Complete clinical response was associated with better functional outcomes and lesser damage as determined by HAQ-DI of 0[OR10.9; 95%CI (3.3,160)], MRS [OR 3.2; 95%CI (1.4,7.3)] and lesser MDI [OR 1.7; 95% CI (1.1,2.7)] respectively as compared to partial response (unadjusted analysis). Baseline parameters and IIM subsets did not significantly influence the functional outcome and damage. The mortality rate in our cohort is 24/175 (13.7%), the disease-specific mortality rate being 9.1%. Large majority of deaths were early, associated with active disease. We report good long-term outcomes in all major myositis subsets. Partial clinical response to treatment is associated with worse functional outcomes and damage accrual. Death occurs early in association with active disease.

Diagnostic classification of dermatomyositis with and without electrodiagnostic study: real-world clinical practice

Abstract Introduction: The revised European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) 2017 criteria and European Neuromuscular Centre’s (ENMC) 2018 criteria have improved diagnostic accuracy for dermatomyositis (DM). However, electromyography (EMG) was not included in the diagnostic criteria. We evaluated the usefulness of EMG under both criteria in the classification of DM and its amyopathic subtypes for patients who had rash with or without muscle weakness. Methods: In this retrospective study, 20 patients who were classified into DM and alternative diagnoses groups based on the Bohan and Peter (BP) criteria and histopathological findings of muscle and/or skin were included. We then compared the diagnostic accuracy to that of the EULAR/ACR and ENMC criteria. Differences in proportion were determined using Fisher’s exact test. Results: Two patients who had weakness with elevated creatine kinase but no typical DM features on muscle biopsies were incorrectly excluded as alternative diagnoses using BP criteria. Both EMGs demonstrated presence of myopathic recruitment pattern and spontaneous activity in the proximal and distal muscles, consistent with the clinical phenotype. Two patients with a final diagnosis of systemic lupus erythematosus were incorrectly classified as DM by EULAR/ACR and ENMC criteria, but EMG demonstrated no evidence of muscle inflammation. Conclusion: Electromyography is valuable in identifying mild myopathy among DM patients with subtle clinical muscle weakness, allowing better classification of DM subtypes. Absence of EMG signs indicating muscle involvement provides clues for alternative diagnosis. In addition, EMG aids in interpretation of inconclusive muscle biopsy results. Therefore, EMG should be performed for every suspected DM patient.

Speckle-tracking global longitudinal strain as a predictor of clinical outcomes in patients with idiopathic inflammatory myopathies

Abstract Background Idiopathic inflammatory myopathies (IIM) are systemic immune-mediated diseases that involve the skeletal muscle and several other organ systems, including the heart. Nonetheless, cardiac involvement in IIM is frequent and initially subclinical. Previous studies have demonstrated how speckle-tracking-derived global longitudinal strain (GLS), as a measurement of the subclinical systolic ventricular dysfunction, is significantly lower in IIM compared to healthy controls. Purpose To assess the progression of myocardial deformation in patients with IIM and test GLS as a prognostic marker of death and cardiovascular events. Methods We enrolled all consecutive patients with a diagnosis of IIM sent to our Cardiology Clinic. The diagnosis of definite idiopathic polymyositis or idiopathic dermatomyositis as made according to the Bohan and Peter criteria and confirmed by muscle biopsy. Patients with inclusion body myositis, necrotizing autoimmune myositis, overlap myositis, and juvenile myositis were excluded from our study. All patients underwent full evaluation, including clinical, ecg and echocardiographic assessment as well as GLS calculation both at baseline and follow up appointments. Primary endpoint was a composite of death and cardiovascular events. Results 41 consecutive patients (28 females, 58±15 years) with IIM were consecutively enrolled and followed up for a median of 8 years (4-11 years). During follow-up, a progressive worsening of LVEF (-4%; p=.03) and left GLS (LGLS: +3%; p=.04) was shown, along with an increase in atrial volumes (iLAV: +8 cm2/m2; p=.02; iRAV: +10 cm2/m2; p=0.01) and estimated filling pressures (E/e': +2; p=.01). A left GLS (LGLS) > -16% predicted the composite endpoint with a sensitivity of 80% and a specificity of 67% (AUC 0.74). Estimated survival from the composite endpoint was 85% for the normal LGLS group and 35% for the impaired LGLS group (Figure 1). Right GLS was not significantly associated with the primary endpoint. Conclusions Heart involvement is becoming a major cause of death in patients with myositis. Data reported that subclinical heart involvement, characterized by biochemical and instrumental modifications, is estimated to affect around 70% of patients with myositis. Cardiac involvement in IIM is often subclinical in the early stages of the disease. GLS has been proven to be an effective tool to predict heart disease. Our results show that GLS worsens over time and can be used as a possible predictor of death and cardiovascular events in this population.Figure 1

Characteristics and Outcomes of Juvenile Dermatomyositis (JDM) in Thai Children: Experience from a Tertiary Referral Center

Background: Juvenile dermatomyositis (JDM) is the most common autoimmune myositis in children. However, there is a paucity of data on the clinical characteristics of JDM patients in Thailand. Objective: To describe the clinical manifestations, investigations, treatments, complications, and outcomes of JDM in Thailand. Materials and Methods: A bidirectional descriptive study based on past medical records review. All children younger than15 years diagnosed with JDM by Bohan and Peter criteria at King Chulalongkorn Memorial Hospital between January 2010 and December 2022 were enrolled. Results: Thirteen cases were identified with 69% female. The median age at diagnosis and median time to diagnosis were 3.4 (IQR 2 to 6.5) years and 3.5 (IQR 1.2 to 8) months, respectively. The common clinical presentations at disease onset were weakness at 100%, Gottron papules at 69%, and heliotrope rash at 46%. Lactate dehydrogenase was elevated in all cases at diagnosis. Evidence of muscle inflammation was found in 78% of biopsies, 80% of EMGs, and 100% of MRIs. The most common myositis specific Ab was anti-NXP2 at 64%. Most patients had polyphasic disease courses. More than half of the patients, or 62%, developed calcinosis. Six of thirteen cases received recommended treatment with prednisolone and methotrexate at diagnosis. One patient with calcinosis had a good response with infliximab. Conclusion: The present review underscores that JDM patients with younger age at diagnosis will need to be monitored closely and need aggressive long-term treatment. Prompt treatment should be managed according to the severity of symptoms to improve clinical outcomes and prevent serious complications. Keywords: JDM; Calcinosis cutis; Myositis autoantibody; Children; Developing countries

P148 Long-term survival of patients with idiopathic inflammatory myopathies: Anatomy of a single-center cohort

Abstract Background/Aims Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of immune-mediated systemic diseases, characterized by muscle inflammation and multiple systemic manifestations. We aimed to characterize clinical manifestations, course, treatment, and mortality of IIM patients. We have also attempted to assess predictors of mortality in IIM. Methods Retrospective single center study IIM patients followed between 1980 and June 2022, including IIM patients fulfilling three or four of the Bohan and Peter criteria. Patients were divided in 6 groups: adult-onset polymyositis (APM), adult-onset dermatomyositis (ADM), juvenile-onset dermatomyositis (JDM), ‘overlap’ myositis (OM), cancer-associated myositis (CAM), and antisynthetase syndrome (ASyS). Sociodemographic, clinical and immunological features and treatment were collected. Additionally, disease complications and causes of death were recorded. The log rank test was used to compare survival curves between subgroups. The Cox proportional hazards regression was used to assess predictors of mortality. Results A total of 158 patients were included with a mean age at diagnosis of 40.81±15.63 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. The majority of patients presented with both upper and lower limb involvement (89.2%), with a mean creatinine kinase level of 4423 ± 7633 U/L. Electromyography, muscle biopsy and magnetic resonance were positive for active myositis in 81.3% (104/128), 77.7% (101/130) and 40.9% (54/132), respectively. Antinuclear antibodies were positive in 62.4% of the patients. Remitting and relapsing (RR) was the most common disease course (35.4%). Most patients were treated with a combination of steroids and one-to-three immunosuppressive drugs (74.1%). Interstitial lung disease, gastrointestinal and cardiac involvement were frequent, affecting 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 13.61 ± 10.24 years, 46 (29.1%) have died, mainly due to infection (28.3%), followed by malignancy (19.6%) and cardiovascular events (10.9%). Positive biopsy (p = 0.044), Jo-1 (p = 0.039), malignancy (p = 0.026), cardiac involvement (p = 0.011) and infections (p = 0.016) were associated with mortality. Older age at diagnosis (HR:1.058, 95CI 1.031-1.085), cardiac involvement (HR: 3.23, 95CI 1.60-6.53), and malignancy (HR 2.20, 95CI 1.09-4.44) were independent predictors of mortality. Conclusion IIM is a rare disease with important systemic complications. Older age at diagnosis, cardiac involvement, and malignancy are independent predictors on mortality. Early diagnosis and aggressive treatment of cardiac involvement could improve survival of these patients. Disclosure F. Guimarães: None. R. Yildirim: None. D.A. Isenberg: None.

E079 Preliminary analysis of autoantibody profiles of autoimmune inflammatory myopathies: study from a single North Indian tertiary care centre

Abstract Background/Aims Studies in autoimmune inflammatory myositis (AIM) have shown a strong role of autoantibodies in the diagnosis and prognosis of patients with myositis. This ongoing study shares the preliminary data of 139 patients with AIM from a North Indian tertiary care centre. This prospective, observational study was conducted at a 1250-bedded hospital to assess the prevalence of myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) in patients from the Indian subcontinent with AIM and the correlation of these antibodies with clinical features. Methods From November 2016 to September 2022, patients with AIM (satisfying the Bohan and Peter criteria of 1975) attending the Rheumatology and Clinical Immunology Department of Medanta Hospital were included after taking their informed consent, and divided into subgroups as dermatomyositis (DM), polymyositis (PM), CTD-associated myositis (CTD-M), cancer-associated myositis (CAM), and juvenile myositis (JM). The Institutional Ethics Committee approved the study. Clinical data and sera from patients were collected and analysed. Results The study included 139 individuals with a mean age of 45.4 years. Fifty-two had DM, 49 had PM, 25 had CTD-M, 6 had CAM, and 7 had JM. ANA positivity was found in 67.70%, MSA in 22.3%, MAA in 25.4%, and both in 12.3%. Antibodies against Mi-2 were identified in 13 (28.9%) patients, Jo-1 in 14 (32.50%), PL-7 in 3 (6.7%), PL-12 in 4 (8.9%), SRP in 9 (20%), and MDA-5 and NXP2 in 1 (2.2%) patient each. Antibodies against Ro were found in 28 (57.1%) of the patients, RNP in 8 (16.3%), and PM-Scl in 9 (18.4%). Mi-2 antibodies were mostly identified in DM patients and were significantly associated with skin rash. SRP positivity was mostly found mainly in PM. Raynaud's and ILD were linked to the presence of Jo-1 and Ro antibodies. Malignancy screening was negative in NXP2 and TIF1γ antibody-positive patients. Conclusion MSA was found in 22.3% of cases and MAA in 25.4%. Mi-2 antibodies were linked to rash, but none had ILD, whereas Jo-1 antibodies were linked to mechanic hands, arthritis, and ILD. We aim to gather more strong results in the future as additional patients are recruited in this continuing trial. Disclosure S. Dhuria: None. P. Khatri: None. N. Negalur: None. K. Telang: None. S. Ghosh: None. D. Yadavalli: None. V. Singal: None. R. Gupta: None.

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

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. 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. 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. 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.

Clinical spectrum and outcomes of idiopathic inflammatory myopathies in South Africans.

Idiopathic inflammatory myopathies (IIM) are rare diseases for which there is a paucity of data in Africa. We undertook a retrospective records review of clinical and laboratory features of patients with IIM attending a tertiary service in Gauteng, South Africa. Case records of patients seen between January 1990 and December 2019 and fulfilling the Bohan and Peter criteria for IIM were reviewed for demographics, clinical features, special investigations and drug therapy. Of 94 patients included in the study, 65 (69.1%) had dermatomyositis (DM) and 29 (30.9%) had polymyositis (PM). Overall, the mean (SD) age at presentation and disease duration were 41.5 (13.6) and 5.9 (6.2) years, respectively. 88 (93.6%) were Black Africans. The most common cutaneous features in DM patients were Gottron's lesions (72.3%) and abnormal cuticular overgrowth (67.7%). Dysphagia was the most common extra-muscular feature (31.9%), more so in PM than DM (p = 0.02). Creatine kinase, total leucocyte count and CRP were similarly higher in PM than DM patients (p = 0.006, 0.002, and 0.01, respectively). Anti-nuclear and anti-Jo-1 antibodies were positive in 62.2 and 20.4% of patients tested, respectively, the latter significantly more in PM than DM patients (OR = 5.1, p = 0.03) and more likely to be positive with ILD (p = 0.001). Corticosteroids were prescribed in all patients, 89.4% had additional immunosuppressive drugs and 6.4% required intensive/high care. Malignancies occurred in three patients, all of whom had DM. There were seven known deaths. The present study provides further insights into the spectrum of clinical features of IIM, especially cutaneous features of DM, anti-Jo-1 antibodies and associated ILD, in a cohort of predominantly black African patients.

Osteonecrosis in patients with juvenile dermatomyositis: is it associated with anti-MDA5 autoantibody?

Dear Editor, Data on osteonecrosis (ON) in JDM are limited [1]. It is usually considered as the result of corticosteroid therapy. Herein, we report a case series of five patients among a cohort of 71 patients with JDM who developed severe ON. All of them had anti-MDA5 positive JDM, which suggests that MDA5-positive JDM patients may have predisposing factors for the development of ON. We retrospectively reviewed the cohort of 71 patients with JDM followed in the Paris referral center for Rare Paediatric Rheumatism and systemic autoimmune diseases (RAISE), between December 2010 and December 2021. Inclusion criteria were: (i) diagnosis of JDM, according to Bohan and Peter criteria with a follow-up of at least 2 years; and (ii) ON diagnosed by bone MRI. During the period of inclusion, myositis-specific antibodies (MSA) were searched once for in all the patients by dot-blot immunoassay using Euroline Autoimmune Inflammatory Myopathies 16 Ag (Euroimmun) and Blue Diver PMS12-24 (D-Tek). IFN-α2 protein concentration was measured by SIMOA assay (Quanterix Homebrew). All statistical analyses were performed using GraphPad Prism (version 9.1.1). After parental consent, patients were registered in the French rare diseases National database (BAMARA). This study was approved by the Ethics board of Necker hospital.

Incidence, Prevalence, and Mortality of Dermatomyositis: A Population-Based Cohort Study.

We aimed to determine the population-based incidence, prevalence, and mortality of dermatomyositis (DM) using European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) criteria. This population-based cohort study included incident DM from January 1, 1995 to December 31, 2019. We manually reviewed all individuals with at least 1 code for DM or polymyositis to determine if they met EULAR/ACR criteria, subspecialty physician diagnosis, and/or Bohan and Peter criteria. We age- and sex-adjusted incidence and prevalence estimates to the US non-Hispanic White year 2000 population and estimated prevalence on January 1, 2015. Standardized mortality ratios (SMRs) with 95% confidence intervals (95% CIs) compared observed to expected mortality adjusting for age, sex, and year. We identified 40 cases of verified DM, with 29 cases incident in Olmsted County from 1995 to 2019. The mean age was 57 years, 26 (90%) were female, and 12 (41%) had clinically amyopathic DM (CADM). The median follow-up time was 8.2 years. The overall adjusted incidence of DM was 1.1 (95% CI 0.7-1.5) per 100,000 person-years, and prevalence was 13 (95% CI 6-19) per 100,000. The SMR was significantly elevated among the myopathic DM cases (3.1 [95% CI 1.1-6.8]) but not CADM cases (1.1 [95% CI 0.2-3.3]). The positive predictive value of ≥2 DM codes was only 40 of 82 (49%). This population-based study found that DM incidence and prevalence were higher than previously reported. Mortality was significantly elevated for myopathic DM but not for CADM.

Elevated serum levels of soluble T cell immunoglobulin and mucin-containing-molecule-3 in patients with idiopathic inflammatory myopathy.

Dear Editor, T cell immunoglobulin and mucin-containing-molecule-3 (TIM-3), an important immune-checkpoint molecule, is a transmembrane glycoprotein expressed by T lymphocytes that functions in immune response and tolerance in autoimmune diseases [1]. Soluble TIM-3 (sTIM-3) is produced by alternative splicing and cleavage, and may negatively regulate T cell-mediated immune responses [2, 3]. Myositis is a common rheumatic immune-related adverse event that can occur during treatment with immune-checkpoint inhibitors [4]. However, whether immune-checkpoint proteins, including TIM-3, exert opposite effects in autoimmune diseases and cancers remains debatable. This cross-sectional study assessed serum sTIM-3 levels in patients with idiopathic inflammatory myopathy (IIM), which is characterized by muscle fibre necrosis and infiltration of inflammatory cells, particularly activated T cells and phagocytes. Seventy adult patients with IIM and 29 healthy age- and sex-matched controls were recruited at the Department of Rheumatology and Immunology, West China Hospital, Sichuan University, from May 2021 to July 2022. All patients met the Bohan and Peter criteria and the EULAR/ACR criteria (2017), and those with immune-mediated necrotizing myopathy (IMNM) met the European Neuromuscular Centre criteria (2017). Participants <18 years of age; patients with other autoimmune diseases, tumours, HIV infection, chronic liver disease, or other muscle diseases; pregnant or lactating women; and patients who had undertaken strenuous exercise within 1 week prior to recruitment were excluded from the study. Sera samples from four patients with lipid storage myopathy (LSM) were used as the non-IIM group. Disease activity was determined using the myositis activity visual analogue score (VAS), interstitial lung disease (ILD) was confirmed by high-resolution CT, and serum sTIM-3 levels were measured by ELISA (RX105593H; Ruixinbio, Quanzhou, China). Spearman correlations between serum sTIM-3 levels, clinical indicators, and disease activity were determined. This study complied with the Declaration of Helsinki and was approved by the Ethics Committee of the hospital (No. 521, 2021).

Performance of the 2017 European Alliance of Associations for Rheumatology/American College of Rheumatology Classification Criteria in Patients With Idiopathic Inflammatory Myopathy and Anti-Melanoma Differentiation-Associated Protein 5 Positivity.

This study aimed to evaluate whether the 2017 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria for adult and juvenile idiopathic inflammatory myopathies (IIMs) could appropriately classify the diagnosis in adult patients with anti-melanoma differentiation-associated protein 5 (anti-MDA-5)-positive IIM. In addition, this study sought to determine whether a status of anti-MDA-5 positivity could be incorporated into the EULAR/ACR IIM classification criteria set and whether the recently modified criteria based on the presence of myositis-specific autoantibodies (MSAs) could be used to appropriately classify the diagnosis in patients with anti-MDA-5-positive IIM. Consecutive adult patients clinically diagnosed as having anti-MDA-5-positive IIM from 10 hospitals in Hong Kong were retrospectively recruited; patient characteristics were obtained from electronic medical records. We used a commercial line blot immunoassay to detect MSAs. We also determined a proposed set of phenotypic-serologic classification criteria specific for anti-MDA-5. In the patient cohort (n=120; 31.7% with dermatomyositis, 68.3% with clinically amyopathic dermatomyositis [CADM]), the diagnosis could be classified with the EULAR/ACR criteria in 86 patients (71.7%) and with the Bohan and Peter criteria in 49 patients (40.8%). However, when combined with criteria specifically modified for CADM, the diagnosis could be classified by the Bohan and Peter criteria in 76.7% of patients. We observed that the sensitivity of the EULAR/ACR criteria could be improved to 98.3% if anti-MDA-5 antibody-positive status was considered as one of the criteria. The MSA-based criteria had 100% sensitivity. When we applied our proposed specific phenotypic-serologic criteria for the classification of patients with anti-MDA-5 antibodies, 97.5% of patients were able to be classified as having IIM. In this cohort of patients with anti-MDA-5-positive IIM, the diagnosis could not be classified by the EULAR/ACR criteria in almost 30% of patients. We suggest incorporating anti-MDA-5 antibody positivity as a criterion into existing criteria sets or developing specific criteria for patients with anti-MDA-5-positive IIM.

Dysferlinopathy misdiagnosed with juvenile polymyositis in the pre-symptomatic stage of hyperCKemia: a case report and literature review

BackgroundDysferlinopathy encompasses a group of rare muscular dystrophies caused by recessive mutations in the DYSF gene. The phenotype ranges from asymptomatic elevated serum creatine kinase (hyperCKemia) to selective and progressive involvement of the proximal and/or distal muscles of the limbs. Bohan and Peter criteria are the most widely used for the diagnosis of polymyositis, but they have limitations and can misclassify muscular dystrophies with inflammation as polymyositis. Most dysferlinopathy patients have muscle biopsies with inflammation and thus are vulnerable to misdiagnosis with polymyositis and inappropriate treatment with steroids and immunosuppressors.Case presentationWe describe a 14 years-old male patient who was referred for assessment of asymptomatic hyperCKemia (26,372 IU/L). An X-linked dystrophinopathy initially was ruled out by direct genetic testing. Juvenile polymyositis was considered based on muscle biopsy, creatine kinase levels, and electromyography changes. Corticosteroid treatment triggered proximal lower limb muscular weakness, and no full muscular strength recovery was observed after corticosteroid withdrawal. Based on these observations, a limb-girdle muscular dystrophy (LGMD) was suspected, and LGMDR2 was confirmed by whole exome sequencing.ConclusionWe report a dysferlinopathy patient who was misdiagnosed with juvenile polymyositis and explore in a literature review how common such misdiagnoses are. With diagnosis based only on routine clinicopathological examinations, distinguishing an inflammatory myopathy from dysferlinopathy is quite difficult. We suggest that before establishing a diagnosis of “definite” or “probable” juvenile polymyositis, according to Bohan and Peter or current ACR/EULAR criteria, a muscular dystrophy must first be ruled out.

AB1518 CASE REPORT OF A HARD TO TREAT DERMATOMYOSITIS AFTER A COVID-19 INFECTION AND SUBSEQUENT VACCINATION

BackgroundA 50 years old woman, a medical doctor, came to our department with symmetrical proximal muscular weakness, several months after Covid-19 infection and three weeks after a second dose of Covid-19 mRNA vaccine. The patient had no prior or family history of autoimmune diseases and take no medicines. In the past she undergone an operation for double-kidney with frequent urinary infections. Objective findings have shown symmetrical proximal muscular weakness and classic sings of dermatomyositis - Gottron’s papules, shawl and holster signs, periungual vasculitis.ObjectivesWe present a case of a 50 old woman with clinical and laboratory proven dermatomyositis, starting three weeks after a second dose of a Covid1-19 mRNA vaccine without other reasons.MethodsThe laboratory tests showed elevated CPK, lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase, high ANA – 1:1280 and myositis specific autoantibodies- anti-NXP2 and anti-Mi-2- beta. The electromyography showed myopathic changes and the muscle MRI – symmetrical edema of mm.obturator and mm.adductor brevis. We exclude diseases that may mimic inflammatory myopathies. We made a cancer screening – whole body MRI, colonoscopy, gastroscopy, mammography and gynecological exam, immunoblot for detection of paraneoplastic syndrome-associated neuronal antibodies, with no detection of cancer. Muscle biopsy of m.vastus lateralis showed attenuating muscle inflammation with advancing muscle atrophy and fibrosis.ResultsThe diagnose dermatomyositis was made according Bohan and Peter criteria and we start a high dose (1mg/kg/day) glucocorticoid therapy with good initial clinical and laboratory effect. Two months after starting a therapy muscle weakness worsened together with difficulty of swallowing. We excluded steroid myopathy after second EMG and lack of improvement when tapering the GS dose. Methotrexate 20 mg/weekly was added as a steroid sparing drug with good response, but was stopped because flare of pyelonephritis. Accordning to the opinion of dermatologist hydroxychloroquine was started for a couple of weeks, because of active skin manifestations. Muscle weakness worsened on the background of treatment, which was stopped. We started a therapy with intravenous immunoglobulins and considered therapy with cyclophosphamide or azathioprine after urinary infection. Because the patient was infected for a second time with covid-19, although vaccine, we continued only with glucocorticoids and antiosteoporotic therapy.ConclusionThe etiology and pathogenesis of inflammatory myopathies are not fully clarified so far. We speculate that the infection with Covid-19 as well as mRNA vaccine trigger inflammatory myopathy and compromise the patient’s immunity for poor treatment response with glucocorticoids and immunosuppressives. On the other hand advanced muscle atrophy and fibrosis within a short period show that suspected triggering factors could be a reason for difficult to treat such type of dermatomyiositis.Disclosure of InterestsNone declared

Clinical Features of Anti-Synthetase Syndrome Associated with Prognosis in Patients with Dermatomyositis and Polymyositis.

We evaluated whether the clinical features of anti-synthetase syndrome (ASA)—myositis, fever, arthritis, mechanic’s hand, Raynaud’s phenomenon and interstitial lung disease—are relevant to prognosis in patients with dermatomyositis/polymyositis (DM/PM). A retrospective analysis was performed to identify patients diagnosed with DM/PM according to Bohan and Peter criteria. Clinical information, laboratory data and the presence of ASA clinical features at disease diagnosis were searched, and the outcomes of all-cause mortality, intensive care unit admission and disease remission at 1 year were assessed. Among the 86 patients included, fever (36.0%) and interstitial lung disease (26.7%) were the most common ASA clinical features. During the follow-up, 12 patients experienced death, and 7 of the 12 deaths (58.3%) occurred within 3 months of DM/PM diagnosis. Mortality was more frequently observed in those presenting with fever than in those without (25.8% versus 7.3%, p = 0.024). Multivariable Cox proportional analysis revealed that male sex (hazard ratio [HR] 5.53, 95% confidence interval [CI] 1.65, 18.49, p < 0.01) and fever (HR 4.20, 95% CI 1.26, 14.01, p = 0.02) independently predicted mortality. The clinical impact of fever was consistent in both sexes. Fever could be a warning signal heralding the poor outcome of mortality in patients with DM/PM, especially in early disease phases.

A juvenile dermatomyositis: demographics, characteristics and disease outcome in an Egyptian cohort.

To study the demographics, characteristics, management and disease outcome of Egyptian children with juvenile dermatomyositis (JDM). Retrospective analysis of the records of 134 JDM patients attending two centres in Cairo, Egypt from January 2010 to December 2019. A total of 128 patients were included in the study, all of which fulfilled either the Bohan and Peter criteria and/or the EULAR/ACR classification criteria of 2017. The mean age of disease onset was 5.9±2.8 years and the follow-up duration were 6±3.2 years. Female to male ratio was 2.2:1. Constitutional manifestations and cutaneous skin ulcers were common, while gut vasculopathy was rare in our patients. Heliotrope rash was the commonest skin manifestation. Lactate dehydrogenase enzyme was more frequently elevated than creatine kinase. Electromyography was the most frequently used diagnostic procedure, while muscle biopsy and muscle MRI were not commonly done in our patients. Glucocorticoids, methotrexate, hydroxychloroquine, mycophenolate mofetil and IVIG were the most frequently used medications. Sixty (46.9 %) of the patients had clinically inactive disease, at the last follow-up visit. Chronic skin disease, residual muscle weakness, calcinosis and growth failure were among the most common cumulative damage manifestations. The mortality rate was 1.6% over the follow-up period, one death was due to severe infection, and the other due to respiratory failure. Although our patients shared several similarities with their peers in the Middle East and in Europe, there were some striking differences. These differences can be attributed to the ethnic and environmental disparities.

Preliminary validation of muscle ultrasound in juvenile dermatomyositis (JDM).

To compare muscle ultrasound (MUS) parameters in patients with juvenile JDM and healthy controls, and examine their association with JDM disease activity measures and MRI. MUS of the right mid-rectus femoris was performed in 21 patients with JDM meeting probable or definite Bohan and Peter criteria and 28 demographically matched healthy control subjects. MUS parameters were quantitated by digital image processing and correlated with JDM disease activity measures and semi-quantitative thigh MRI short tau inversion recovery (STIR) and T1 scores. Rectus femoris MUS echogenicity was increased (median 47.8 vs 38.5, P = 0.002) in patients with JDM compared with controls. Rectus femoris MUS echogenicity correlated with Physician Global Activity (PGA), Manual Muscle Testing (MMT), and Childhood Myositis Assessment Scale (CMAS) (rs 0.4-0.54). Some MUS parameters correlated with functional quantitative measures of muscle strength: resting RF area on MUS strongly correlated with knee extension quantitative muscle testing (rs 0.76), and contracted area correlated with proximal MMT, knee extension quantitative muscle testing, and CMAS (rs 0.71-0.80). MUS echogenicity correlated with both STIR and T1 MRI (rs 0.43), and T1 MRI correlated inversely with RF contracted area (rs -0.49) on MUS. There were differences in pre- and post-exercise vascular power and colour Doppler on MUS in patients with JDM vs controls, with the percentage change of post-exercise vascular power Doppler lower in JDM compared with controls (7.1% vs 100.0%). These data suggest MUS may be a valuable imaging modality to assess JDM disease activity and damage.

P052 Juvenile dermatomyositis, a multi-faceted disease

Abstract Background Dermatomyositis is a rare disease. In children, the incidence is 2–3 per million habitants. It is a serious disease whose mortality is &amp;lt; 5% but whose complications and long-term prognosis remain pejorative for some children. The objective is to report the epidemiological, clinical, therapeutic options and the course of a retrospective series carried out at the CHU pediatric center of Sétif (Algeria) comprising 8 cases of juvenile dermatomyositis. Methods The mean age of onset is 7.7 years (0–15.5 years), The sex ratio was 0.1; The diagnosis delay averaged at 4, 4 months. At disease onset, 100% had rash, 84% a eyelids telangiectasias, 40% Gottron nodules, 90% muscular weakness, 40% arthritis, 13% fever, and 25% dysphagia. The muscular enzymes were increased in 8 cases. The DNA antibodies were present in one patient with myositis overlap, NXP was positive in one child. The electromyogram is myogenic in all patients. Seven patients underwent a histopathological exam, showing interstitial and parenchymal myositis. Treatment regimens were variable depending on the severity of the disease onset. All children were treated with steroids as the first line. Methotrexate was prescribed in 5 cases (62.5%). The immunoglobulin was indicated in 2 cases. The failure to thrive was observed in 2 (25%), and one child died following aspiration pneumonia. Results The dermatomyositis diagnosis is based on the Bohan and Peter criteria. The clinical characteristics of our series are in line with the literature data with a predominance of cutaneous and muscular involvement. However, some specificities are individualized: a case of overlapping myositis with lupus, a case of extensive calcinosis. The treatment was based on corticosteroids and methotrexate. Conclusion Dermatomyositis juvenile is a rare disease with a pejorative prognosis requiring a multidisciplinary management.

Characteristics of idiopathic inflammatory myopathies with novel myositis-specific autoantibodies.

In recent years, many novel myositis-specific autoantibodies (MSAs) have been identified. However, their links with the pathogenesis and clinical manifestations of inflammatory myopathies remain uncertain. To characterize the population of adult dermatomyositis (DM) and polymyositis (PM) patients treated at our center for autoimmune diseases using clinical and laboratory measures. According to the Bohan and Peter criteria, we retrospectively analyzed patients who fulfilled diagnostic criteria for DM or PM. Myositis-specific autoantibodies and myositis-associated autoantibodies (MAAs) were identified using immunoblot assays. Fifty-one PM (71% women) and 36 DM (67% women) Caucasian patients with a median age of 58 (range: 21-88) years who met the definite or probable diagnostic criteria for myositis were included in the study. Myositis-specific autoantibodies were identified in 63 (72%) patients, whereas MAAs were observed in 43 (49%) of them. Interstitial lung disease (ILD) was characteristic of PM patients (67%, χ2 with Yates's correction (χc2) = 13.8078, df = 1, p = 0.0002), being associated with anti-Jo-1 or anti-PL-12 antibodies (fraction comparison test (FCT) 6.4878, p < 0.0001, 6.8354, p = 0.0003, respectively). Interestingly, among patients with anti-MDA5 antibodies (n = 8, 9.2%), all but one had an amyopathic form, with more frequent ILD, skin changes and arthralgias than observed in other patients (FCT 4.7029, p = 0.0228 and p = 7.7986, p = 0.0357, p = 4.7029 and p = 0.0228, respectively). Anti-signal recognition particle (SRP) was strongly associated with the Raynaud's phenomenon (FCT 4.1144, p = 0.0289) and the highest muscle injury markers (Mann-Whitney U test, z = 2.5293, p = 0.0114). Malignancy was recorded in 14 (16%) patients and was equally common in those with PM and DM. The anti-TIF-1γ was the most frequently related to cancer χ2 = 14.7691, df = 1, p < 0.0001). The anti-Mi-2α, similarly prevalent in DM and PM, was typically accompanied by skin changes (FCT 7.7986, p = 0.0357) but not ILD (FCT 8.7339, p = 0.0026). Identification of MSAs might help to predict the clinical course of the autoimmune myopathy and malignancy risk. However, these antibodies were absent in about 30% of patients with typical PM or DM manifestations, which encourages further research in this area.

P153 Characteristics of anti-melanoma differentiation-associated gene 5 positive dermatomyositis in Singapore

Abstract Background/Aims Anti-melanoma differentiation-associated gene 5 (MDA5) Ab positive associated dermatomyositis (DM) patients with rapidly progressive-interstitial lung disease (RP-ILD) have poor survival rates. The aim of this study was to determine the various characteristics in Singaporean patients with anti-MDA5-Ab associated DM. Methods A chart review was undertaken of 84 DM patients with positive myositis specific antibodies, diagnosed between January 2015 to July 2019, at a major tertiary centre in Singapore. All had confirmed probable or definite DM according to the Bohan and Peter criteria, and only those with an International Myositis Classification Criteria score of at least 55% (probable idiopathic inflammatory DM) were included. Results 18 out of 84 were anti-MDA5-Ab positive (See Table 1 for summary). Features more common in the anti-MDA5 Ab positive vs. the anti-MDA5 Ab negative cohort included: inverse Gottron’s papules (27.8% vs. 3%, p = 0.001) palmar papules (27.8% vs. 0%, p &amp;lt; 0.001), violaceous rash (55.6% vs. 16.7%, p = 0.001), cutaneous ulcers (66.7% vs. 6.1%, p = &amp;lt;0.001), clinically amyopathic DM (50% vs. 22.7%, p = 0.023) and polyarthritis (38.9% vs. 12.1%, p = 0.0009). The anti-MDA5 Ab positive cohort had a lower median creatine kinase (IU/L) versus the anti-MDA5 Ab negative cohort; 328 [60-3254] vs. 1318 [61-36776], (p = 0.0027). ILD was more common in the anti MDA5 Ab positive vs. anti-MDA5 Ab negative cohort (61.1% vs. 34.8%; p = 0.044). Of these anti-MDA5 Ab positive with ILD, 45.5% had RP-ILD, 27.3% had either chronic ILD or asymptomatic ILD respectively. In contrast, only 17.4% had RP-ILD in the anti-MDA5 Ab negative cohort. The mortality rate in the anti-MDA5 Ab positive vs. negative cohort was higher (33.3% vs. 24.2%). Patients with both Ro-52 and MDA5 Ab positivity had a higher incidence of cutaneous ulcers, pneumothorax, ILD and mortality. Of those anti-MDA5-Ab positive cases that survived, treatment included either rituximab and/or tofacitinib. Conclusion In our population, anti-MDA5 Abs associated DM is a distinct clinical subset of DM and associated with increased mortality. Better recognition of these distinct clinical features will enable early diagnosis, risk stratification and aggressive treatment to improve survival. Disclosure J. Low: None. C. Chua: None. W. Lim: None. L. Koh: None. M. Manghani: None.