Inflammatory muscle disease - An update

Clinical implications and mechanism of complement C1q in polymyositis

Polymyositis (PM) is the most common autoimmune disease in neurology and among muscle disorders; it is of great significance to thoroughly understand the mechanism of PM to find new diagnosis and treatment methods. This research intends to elucidate the clinical implications and mechanisms of complement C1q in polymyositis (PM). One hundred fifteen PM patients (research group, RG) and 120 healthy subjects (control group, CG) who visited our hospital between March 2017 and March 2020 were selected. Peripheral blood C1q and creatine kinase (CK) levels of both groups were measured, and their correlations with clinical symptoms and prognostic recurrence of PM. Additionally, to further understand the mechanism of action of C1q in PM, we purchased BALB/c mice and grouped them as follows: control group with normal feeding, PM group with PM modeling, intervention group with PM modeling, and intraperitoneal injection of gC1qR monoclonal antibody 60.11, a C1q protein receptor. Inflammatory factors and muscle histopathology were detected in all groups of mice. Finally, rat macrophages (mø) were isolated, and changes in the biological behavior of mø were observed after silencing the expression of gC1qR. Serum C1q and CK were both higher in RG than in CG, with favorable diagnostic effects on PM (P < 0.05). C1q and CK increased in symptomatic anti-ribonuclear protein antibody (RNP)-positive patients but decreased in anti Jo-1 antibody (Jo-1)- and anti-neutrophil cytoplasmic antibody (ANCA)-positive patients (P < 0.05). PM mice were observed with elevated gC1qR, while model mice exhibited severe infiltration of inflammatory cells in muscle tissue, increased pro-IFs, and reduced anti-IFs, and the animals in the intervention group showed improved conditions (P < 0.05). Finally, it was found that CD68, CD86 protein, and invasion capacity of gC1qR-sh-transfected cells decreased, while CD206 and CD163 increased (P < 0.05). C1q is elevated in PM and is strongly linked to the pathological process of PM. Inhibition of gC1qR expression reduced inflammatory infiltration in PM mice.

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.

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%.

K2P2.1 is a regulator of inflammatory cell responses in idiopathic inflammatory myopathies

K2P2.1 (TREK1), a two-pore domain potassium channel, has emerged as regulator of leukocyte transmigration into the central nervous system. In the context of skeletal muscle, immune cell infiltration constitutes the pathogenic hallmark of idiopathic inflammatory myopathies (IIMs). However, the underlying mechanisms remain to be elucidated. In this study, we investigated the role of K2P2.1 in the autoimmune response of IIMs. We detected K2P2.1 expression in primary skeletal muscle and endothelial cells of murine and human origin. We observed an increased pro-inflammatory cell response, adhesion and transmigration by pharmacological blockade or genetic deletion of K2P2.1 in vitro and in in vivo myositis mouse models. Of note, our findings were not restricted to endothelial cells as skeletal muscle cells with impaired K2P2.1 function also demonstrated a strong pro-inflammatory response. Conversely, these features were abrogated by activation of K2P2.1 and improved the disease course of a myositis mouse model. In humans, K2P2.1 expression was diminished in IIM patients compared to non-diseased controls arguing for the translatability of our findings. In summary, K2P2.1 may regulate the inflammatory response of skeletal muscle. Further research is required to understand whether K2P2.1 could serve as novel therapeutic target.

Polymyositis following varicella and mumps infection in adults: report of two cases

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.

Idiopathic inflammatory myopathies - The burden of disease: Cohort analysis focusing on damage and comorbidities

INTRODUCTION/BACKGROUND

Idiopathic Inflammatory Myopathies (IIM) continue to be a major clinical challenge worldwide. The exact aetiopathogenesis of this chronic and disabling disease remains elusive, preventing the development of novel and effective therapeutic strategies and leading to a high incidence of damage. The complexity of treating these diseases is even greater due to the numerous comorbidities that affect these patients.

METHODS

Retrospective review of the cohort of patients diagnosed with IIM and followed in a dedicated unit of a tertiary hospital between 1971 and December 2022, with particular attention to damage and comorbidities. Damage was assessed using the Myositis Damage Index. Comorbidities were recorded and analysed as a whole and also assessed using the Charlson Comorbidity Index. Health Assessment Questionnaire (HAQ) Disability Index (DI) was performed by phone call in December 2022, to all patients actively followed-up in the Unit.

RESULTS

Analysis of 149 patients with a mean follow-up of 9 years (range 0-51) revealed >90% with damage and comorbidities. Most comorbidities were a consequence of the damage and were particularly related to prolonged steroid therapy. Cardiovascular damage, which occurred either as cardiovascular risk factors or as end-organ sequelae (cardiovascular disease and chronic kidney disease), was the main cause and a major contributor to death. Depression was also high on the list of associated comorbidities. Median HAQ was 2.09 representing high negative impact in quality of life.

CONCLUSIONS

Although survival rates have increased in recent decades, patients with IIM carry a high burden of disease with poor quality of life, mainly caused by damage and comorbidities. While comorbidities accumulation is the major factor for poor quality of life, damage severity is the main predictor for mortality. Improved therapeutic strategies are needed to reduce the need for steroids and to introduce routine screening and management of comorbidities as an essential partner of immunosuppressive therapy, leading to comprehensive care of myositis patients and effective improvement of their quality of life.

The diagnostic value of urinary N-terminal fragment of titin for skeletal muscle damage in idiopathic inflammatory myopathy

OBJECTIVES

N-terminal fragment of titin (N-titin) is a marker of sarcomere damage in striated muscles; however, its value in patients with IIM (idiopathic inflammatory myopathy) is unclear. This study aimed to investigate the diagnostic value of N-titin for skeletal muscle damage in patients with IIM.

METHODS

Urine samples from 62 patients with IIM, 59 patients with other CTD diseases, and 29 healthy controls were collected to detect N-titin by ELISA assays. Clinical features and laboratory data were all included in logistic regression analysis to obtain the independent predictive factor for skeletal muscle damage.

RESULTS

Urinary N-titin level of the IIM group [168.3 (19.0, 1279.0) pmol/mg cr] was significantly higher than that in CTD controls [2.80 (1.53, 3.60)] and healthy controls [1.83 (1.09, 2.95)] (P < 0.001). IIM patients with skeletal muscle injury had a significantly higher level of urinary N-titin [1001.0, (181.8, 1977.0)] than those without [9.3, (5.8, 23.9)] (P < 0.001). The N-titin level was strongly correlated with CK (r = 0.907, P < 0.001) and muscle disease activity assessment scores by Spearman correlation analysis. After adjusting for the anti-MDA5 antibody and cardiac troponin T, N-titin was shown to independently predict skeletal muscle damage in patients with IIM (odds ratio = 1.035, 95% CI: 1.002, 1.069, P = 0.039). The cut-off value of urinary N-titin to diagnose skeletal muscle damage was 89.9 pmol/mg Cr, with a sensitivity of 87.8% and a specificity of 100% (AUC = 0.971, 95% CI: 0.938, 1.000, P < 0.001).

CONCLUSION

Urinary N-titin is a non-invasive and independent predictive factor for determining skeletal muscle damage in patients with IIM.

The Tuscany Regional Network for rare diseases: from European Reference Networks' experience to registry based organisation and management model for rare diseases

BACKGROUND

In the European Union, a disease is defined as rare when it affects fewer than 1 in 2000 people. Currently, there are up to 8000 described rare diseases (RDs), collectively affecting 30 million people in the European Union. In 2004 Tuscany region (Italy) established a Regional Network of hospital units to ensure highly specialised medical care in the field of RDs. Shortly after the Rare Diseases Registry of Tuscany (Registro Toscano Malattie Rare-RTMR) was implemented. Here we describe the analysis performed on RTMR data which has recently allowed to remap the Network based on European Reference Networks' model.

RESULTS

Data analysis was performed on 60,367 cases registered in RTMR, regarding 628 RDs. Two-hundred and fifteen active presidia have been evaluated. The assignment of each RD to the suitable European Reference Network has been made considering not only the number of registered cases, certifications and treatment plans for each Regional Presidium but also the competence in multidisciplinary management of the patient, from diagnosis to treatment. This evaluation has led to the establishment of twenty-one Regional Coordination Centres. They aggregate and coordinate Hospital Units which diagnose and treat one or a group of related RDs. In case of wide groups of RDs, Clinical Subnets are instituted. Updated statistics regarding RDs in Tuscany, list of RDs and Coordination Centres, as well as information about single Presidia are published and freely available on a designated webpage. Regional Decrees are regularly updated according to the network evolution.

CONCLUSIONS

The Rare Diseases Regional Network in Tuscany, based on the ERN model, has played a pivotal role in enhancing RD management and research. The remapping has led to a dynamic system, following not only scientific research but also the development of Presidia's expertise. By pooling resources and expertise, the network has improved the availability and accessibility of specialized care for patients with RDs. Collaborative efforts, data sharing, and standardized registries are crucial for advancing RD research, improving diagnosis and treatment, and ultimately enhancing the quality of life for individuals living with RDs.

Polymyositis: A Case Report

Inflammatory myopathies are a group of diseases whose common pathway is immune-mediated muscle damage, one of which is polymyositis. The definition of polymyositis is controversial, with proponents advocating a definition based on immunohistochemical and histopathological findings in muscle biopsies, while other proponents advocate a definition based on clinical manifestations and histopathological findings. Polymyositis is a quite rare disease that is clinically characterized by progressive proximal muscle weakness with a symmetric distribution. Within the diagnostic approach, laboratory studies show elevation of sarcoplasmic enzymes; nerve conduction tests are performed, which may aid in distinguishing myopathic causes of weakness from neuropathic disorders; and muscle biopsy is considered the gold standard to diagnose inflammatory myopathy and to distinguish the subclasses. We report the case of a 61-year-old male patient who presented generalized symmetrical weakness, predominantly in the upper extremities, and dysphagia, whose laboratory studies, autoantibodies, and muscle biopsy were confirmatory of this entity.

Pain in individuals with idiopathic inflammatory myopathies, other systemic autoimmune rheumatic diseases, and without rheumatic diseases: A report from the COVAD study

OBJECTIVES

To compare pain intensity among individuals with idiopathic inflammatory myopathies (IIMs), other systemic autoimmune rheumatic diseases (AIRDs), and without rheumatic disease (wAIDs).

METHODS

Data were collected from the COVID-19 Vaccination in Autoimmune Diseases (COVAD) study, an international cross-sectional online survey, from December 2020 to August 2021. Pain experienced in the preceding week was assessed using numeral rating scale (NRS). We performed a negative binomial regression analysis to assess pain in IIMs subtypes and whether demographics, disease activity, general health status, and physical function had an impact on pain scores.

RESULTS

Of 6988 participants included, 15.1% had IIMs, 27.9% had other AIRDs, and 57.0% were wAIDs. The median pain NRS in patients with IIMs, other AIRDs, and wAIDs were 2.0 (interquartile range [IQR] = 1.0-5.0), 3.0 (IQR = 1.0-6.0), and 1.0 (IQR = 0-2.0), respectively (P < 0.001). Regression analysis adjusted for gender, age, and ethnicity revealed that overlap myositis and antisynthetase syndrome had the highest pain (NRS = 4.0, 95% CI = 3.5-4.5, and NRS = 3.6, 95% CI = 3.1-4.1, respectively). An additional association between pain and poor functional status was observed in all groups. Female gender was associated with higher pain scores in almost all scenarios. Increasing age was associated with higher pain NRS scores in some scenarios of disease activity, and Asian and Hispanic ethnicities had reduced pain scores in some functional status scenarios.

CONCLUSION

Patients with IIMs reported higher pain levels than wAIDs, but less than patients with other AIRDs. Pain is a disabling manifestation of IIMs and is associated with a poor functional status.

Risk of Early Infection in Idiopathic Inflammatory Myopathies: Cluster Analysis Based on Clinical Features and Biomarkers

Patients with idiopathic inflammatory myopathies (IIMs), referred to as myositis, are prone to infectious complications, which hinder the treatment of the disease and worsen the outcome of patients. The purpose of this study was to explore the different types of infectious complications in patients with myositis and to determine the predisposing factors for clinical reference. A retrospective study was conducted on 66 patients with IIM who were divided into different subpopulations by an unsupervised analysis of their clinical manifestations, laboratory features, and autoantibody characteristics. Combined with the incidence of infectious complications, the types of infectious pathogens and the sites of infection, the characteristics of infection, and susceptibility factors were explored. Three clusters with significantly different clinical characteristics and coinfection rates were identified (76.2% vs. 41.6% vs. 36.4%, p = 0.0139). Cluster 1 (n = 12) had a moderate risk of infection, with an infection rate of 41.6%. The patients in cluster 1 had a high probability of positive mechanic's hands, periungual erythema, anti-Ro52 antibody, and anti-Jo1 antibody. CD3 and CD4 were the highest among the three groups. Cluster 2 (n = 21) had a high risk of infection, and the incidence of infection was 76.2%. Almost all patients in this cluster had a rash, prominent clinical symptoms, and decreased WBC, PMN, LYM, CD3, and CD4 counts. Cluster 3 (n = 33) had a low risk of infection, with an infection rate of 36.4%. Compared with the other two clusters, cluster 3 (n = 33) lacked a typical rash but had a high ANA-positive rate. The patients in cluster 1 and cluster 3 were mainly infected by viruses, followed by bacterial infections. In cluster 2 patients, bacterial infections were the most prevalent. Fungal and Pneumocystis carinii were common causes of cluster 2 and 3 infections. In addition, the patients within a cluster often have a single infection, and pulmonary infections are the most common. We clustered the patients with IIM complicated with infection into three different types by their clinical symptoms and found that there were differences in the infection risk and infection types among the different cluster groups.

Long-term secular trends in dermatomyositis and polymyositis mortality in the USA from 1981 to 2020 according to underlying and multiple cause of death mortality data

BACKGROUND

People with dermatomyositis (DM) or polymyositis (PM) often die from cancer, pulmonary, cardiac complications, or infections. In such cases, DM or PM might not be designated as the underlying cause of death (UCD) for mortality tabulation. In this study, we investigated DM/PM mortality trends in the USA from 1981 to 2020 with respect to UCD and multiple causes of death (MCD) data.

METHODS

We used the MCD data to identify all deaths with DM or PM mentioned anywhere on the death certificate and as the UCD in the USA from 1981-1982 to 2019-2020. We calculated age-adjusted mortality rates (AAMRs) and annual percentage changes (APCs) based on joinpoint regression analysis.

RESULTS

We identified 12,249 (3985 with DM and 7097 with PM) and 23,608 (8264 with DM and 15,344 with PM) people who died between 1981 and 2020 according to the UCD and MCD data, respectively. For DM, the APC was - 6.7% (from 1981-1982 to 1985-1986), - 0.1% (from 1985-1986 to 2003-2004), and - 1.9% (from 2003-2004 to 2019-2020) according UCD and was - 1.2% (from 1981-1982 to 2003-2004), - 2.5% (from 2003-2004 to 2015-2016), and 2.8% (from 2015-2016 to 2019-2020) according MCD. For PM, the APC was 1.9% (from 1981-1982 to 1989-1990), - 2.3% (from 1989-1990 to 2005-2006), and - 5.2% (from 2005-2006 to 2019-2020) according UCD and was 1.3% (from 1981-1982 to 1991-1992) and - 4.1% (from 1991-1992 to 2019-2020) according MCD.

CONCLUSION

We identified two times as many DM/PM deaths using the MCD as those identified using the UCD. Similar downward DM/PM mortality trends were noted according to UCD and MCD. However, the year of significant decline in PM mortality was about 10 years earlier according to MCD than those according to UCD.

COVID-19 outcomes in patients with Dermatomyositis: A registry-based cohort analysis

BACKGROUND

Patients with rheumatic diseases (RDs) like DM are known to be vulnerable towards various types of infections due to aggressive disease activity mandating high dose immunosuppressive therapy. The severity of COVID-19 in RDs is limited in literature due to the heterogeneous nature of the condition. Therefore, specific details on mortality is essential to navigate any precautions required in the treatment.

OBJECTIVES

To determine outcomes of COVID-19 in DM as compared to controls, and identify the risk association of gender, race, interstitial lung disease, neoplasms, and use of immunosuppressant.

METHODS

Retrospective data of individuals with DM and COVID-19 and the general population with COVID-19 between January 2020 to August 2021 was retrieved from the TriNetX database. 1:1 Propensity Score matching was used to adjust for confounders. We assessed COVID-19 outcomes such as mortality, hospitalisation, ICU admission, severe COVID-19, mechanical ventilation (MV), acute kidney injury (AKI), venous thromboembolism (VTE), ischemic stroke, acute respiratory distress syndrome (ARDS), renal replacement therapy (RRT) and sepsis. Subgroup analyses included gender, race, ILD, cancer patients, disease-modifying rheumatic drugs (DMARDs) use, and glucocorticoids (GC) use.

RESULTS

We identified 5,574 DM patients with COVID-19, and 5,574 general population with COVID-19 (controls). DM with COVID-19 had a lower risk of mortality in comparison to controls [RR 0.76], hospitalisation [RR 0.8], severe COVID-19 [RR 0.76], AKI [RR 0.83], and sepsis [RR 0.73]. Males and African Americans were more likely to develop AKI [RR 1.35, 1.65], while African Americans had higher odds for severe COVID-19 [RR 1.62] and VTE [RR 1.54]. DM with ILD group also experienced higher odds for severe COVID-19 infection [RR 1.64], and VTE [RR 2.06]. DM patients receiving DMARDs and glucocorticoids had higher odds for hospitalisation [RR 1.46, 2.12], and sepsis [RR 3.25, 2.4] Subgroup analysis of 5-year neoplasm history amongst DM patients with COVID-19 was inadequate for meaningful comparison.

CONCLUSION

Dermatomyositis patients without comorbities have reasonable COVID-19 outcomes including mortality and hospitalisation. Black race, male gender, ILD, DMARDS and glucocorticoid users, are associated with poor outcomes.

Profile of specific and associated autoantibodies in patients with idiopathic inflammatory myopathies in a Colombian population

Objectives

Idiopathic inflammatory myopathies (IIMs) are chronic, autoimmune diseases with several forms of presentation. Diagnosis is mostly clinical in our region. Our aim was to evaluate the autoantibody profile of patients with IIMs.

Methods

This study is a cross-sectional study with a prospective recollection of data, conducted between 2019–2021, in a single center in Cali, Colombia. Patients with a clinical diagnosis or suspicion of IIM were included. The presence of myositis-specific/associated antibodies was evaluated by immunoblotting in serum samples. Phenotypic characterization was performed.

Results

A total of 36 patients were included. The mean age was 50.6 (16.7) years, and 20 (55.6%) were female. Eighteen (50%) patients were seropositive, of which 11 (30.5%) presented one positive antibody, with anti-TIF1ɣbeing the most frequent (n = 4, 11.1%), followed by anti-Ro52 (n = 2, 5.6%). Seven patients (19.4%) showed >1 positive antibody. Dermatomyositis was the most frequent type of IIM in seropositive patients (n = 8, 44.4%), followed by anti-synthetase syndrome (n = 4, 22.2%). Weakness was symmetric and presented in the upper and lower extremities in 11 (61.1%) patients each. Both respiratory insufficiency and weight loss were seen in 7 (38.9%) patients, Gottron papules in six (33.3%) patients, and heliotrope rash, esophageal dysmotility, and myalgia in 5 (27.8%) patients. Pulmonary interstitial disease was seen in 4 (22.2%, with antibodies for anti-Ro52, anti-MDA5 + anti-Jo1 + anti-TIF1ɣ, anti-MDA5 + anti-SAE1 + anti-NXP2, and anti-cN1A + anti-Ro52) patients, and malignancy was seen in 2 (11.1%) patients (1 with anti-Mi2β and 1 with anti-TIF1ɣ + anti-Mi2α). In all, 7 (19.4%) patients required intensive care (2 seropositive, 1 with anti-PL7, 1 with anti-MDA5 + anti-Jo1 + anti-TIF1ɣ), and 1 (2.8%) (seronegative) patient died.

Conclusion

This study is the first study in the Southwest of Colombia that evaluates myositis-specific/associated antibodies in IIM. Half of the patients were seropositive. Anti-TIF1ɣwas the most frequent MSA and anti-Ro52 was the most frequent MAA. Several patients presented antibody combinations. Further studies are needed to fully associate phenotypes with antibodies.

Is it really myositis? Mimics and pitfalls

Idiopathic inflammatory myopathies are a heterogeneous set of systemic inflammatory disorders primarily affecting muscle. Signs and symptoms vary greatly between and within subtypes, requiring supportive laboratory and pathologic evidence to confirm the diagnosis. Several studies are typical assessments for patients with suspected inflammatory myopathy, including muscle enzymes, autoimmune markers, imaging, and muscle biopsy. Misdiagnoses of myositis are not only related to the overlap of clinical phenotype with non-inflammatory myopathies, but also due to the limitations of diagnostic tests employed. Since many of the investigative tests are non-specific, they share features with other disorders, including muscular dystrophies, endocrine, toxic, and metabolic myopathies, and other neuromuscular or rheumatologic conditions. Recognizing the limitations of tests and understanding the shared features between inflammatory and non-inflammatory myopathies can help prevent misdiagnosing myositis with one of its several mimics.

Pain profile and opioid medication use in patients with idiopathic inflammatory myopathies

OBJECTIVES

Pain is commonly reported in people living with myositis. This study assesses the presence of pain in the subtypes of myositis as well as the frequency of opioid and non-opioid pain medication use.

METHODS

A survey was developed and distributed by Myositis Support and Understanding, a patient-led advocacy organization, to members of its group. Multivariate logistic regression analysis and chi-squared tests were performed.

RESULTS

A total of 468 participants completed the survey. A total of 423 participants (DM n = 183, PM n = 109 and IBM n = 131) were included, based on reported diagnosis, for final analysis. Some 91.5% of myositis participants reported current or past pain, with 99% attributing their pain to myositis. There was a lower likelihood of pain in participants aged >60 years [odds ratio (OR) 0.2, 95% confidence interval (CI) 0.1, 0.6, P = 0.003]. The percentage of participants reporting pain was statistically different based on myositis type (DM 97.2%, IBM 80.9% and PM 94.5%, P < 0.001), with a higher likelihood of pain in DM compared with IBM (OR 3.7, 95% CI 1.3, 10.2, P = 0.011). There was a lower likelihood of pain in participants aged >60 years (OR 0.2, 95% CI 0.1, 0.6, P = 0.003). Of the 387 participants reporting pain, 335 reported using pain medications (69% prescribed opioids). Male sex, age >60 years and myositis subtype were not associated with likelihood of non-opioid use.

CONCLUSION

Pain is a commonly reported symptom in myositis with variable treatment strategies, including opioid medications. This study highlights the importance of addressing pain as part of myositis treatment as well as the need for future studies understanding treatment effectiveness.

Skeletal Muscle and COVID-19: The Potential Involvement of Bioactive Sphingolipids

SARS-CoV-2 virus infection is the cause of the coronavirus disease 2019 (COVID-19), which is still spreading over the world. The manifestation of this disease can range from mild to severe and can be limited in time (weeks) or persist for months in about 30–50% of patients. COVID-19 is considered a multiple organ dysfunction syndrome and the musculoskeletal system manifestations are beginning to be considered of absolute importance in both COVID-19 patients and in patients recovering from the SARS-CoV-2 infection. Musculoskeletal manifestations of COVID-19 and other coronavirus infections include loss of muscle mass, muscle weakness, fatigue or myalgia, and muscle injury. The molecular mechanisms by which SARS-CoV-2 can cause damage to skeletal muscle (SkM) cells are not yet well understood. Sphingolipids (SLs) represent an important class of eukaryotic lipids with structural functions as well as bioactive molecules able to modulate crucial processes, including inflammation and viral infection. In the last two decades, several reports have highlighted the role of SLs in modulating SkM cell differentiation, regeneration, aging, response to insulin, and contraction. This review summarizes the consequences of SARS-CoV-2 infection on SkM and the potential involvement of SLs in the tissue responses to virus infection. In particular, we highlight the role of sphingosine 1-phosphate signaling in order to aid the prediction of novel targets for preventing and/or treating acute and long-term musculoskeletal manifestations of virus infection in COVID-19.

Standardised interpretation of capillaroscopy in autoimmune idiopathic inflammatory myopathies: A structured review on behalf of the EULAR study group on microcirculation in Rheumatic Diseases

OBJECTIVE

We conducted a systematic review, on behalf of the EULAR Study Group on Microcirculation in Rheumatic Diseases (EULAR SG MC/RD), to investigate the value of nailfold videocapillaroscopy (NVC) in idiopathic inflammatory myopathies (IIM).

METHODS

Three electronic databases were systematically searched to find all relevant manuscripts reporting NVC outcomes in IIM patients. Articles were assessed based on study design, population, NVC methodology and description of NVC results. To allow comparison between the articles, all NVC results were interpreted according to standardised capillaroscopic terminology, as previously consented by the EULAR SG MC/RD and the Scleroderma Clinical Trials Consortium (SCTC) Group on Capillaroscopy.

RESULTS

Of the 653 identified records; five were retained after critical appraisal on title, abstract and manuscript level. A marked difference in NVC was observed between (juvenile) dermatomyositis [(j)DM] versus polymyositis, healthy controls and systemic sclerosis patients. In addition, reduced capillary density and scleroderma pattern seem to be associated with active disease in (j)DM, while immunosuppressive treatment appears to reduce NVC abnormalities.

CONCLUSION

This is the first systematic review investigating NVC in IIM, interpreting the results according to an international consented standardised manner, as proposed by the EULAR SG MC/RD and SCTC Group on Capillaroscopy. We can conclude that NVC presents a promising asset in the diagnosis of (j)DM. Moreover, NVC could be a biomarker for organ involvement and follow-up. Large multicentre prospective standardised studies are further needed to definitely describe associations with clinical and laboratory parameters in the different IIM subtypes.

Clinical features and diagnostic tools in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIMs) are rare autoimmune disorders affecting primarily muscles, but other organs can be involved. This review describes the clinical features, diagnosis and treatment for IIMs, namely polymyositis (PM), dermatomyositis (DM), sporadic inclusion body myositis (sIBM), immune-mediated necrotizing myopathy (IMNM), and myositis associated with antisynthetase syndrome (ASS). The diagnostic approach has been updated recently based on the discovery of circulating autoantibodies, which has enhanced the management of patients. Currently, validated classification criteria for IIMs allow clinical studies with well-defined sets of patients but diagnostic criteria to guide the care of individual patients in routine clinical practice are still missing. This review analyzes the clinical manifestations and laboratory findings of IIMs, discusses the efficiency of modern and standard methods employed in their workup, and delineates optimal practice for clinical care. Α multidisciplinary diagnostic approach that combines clinical, neurologic and rheumatologic examination, evaluation of electrophysiologic and morphologic muscle characteristics, and assessment of autoantibody immunoassays has been determined to be the preferred approach for effective management of patients with suspected IIMs.

Monoclonal Antibodies as Neurological Therapeutics

Over the last 30 years the role of monoclonal antibodies in therapeutics has increased enormously, revolutionizing treatment in most medical specialties, including neurology. Monoclonal antibodies are key therapeutic agents for several neurological conditions with diverse pathophysiological mechanisms, including multiple sclerosis, migraines and neuromuscular disease. In addition, a great number of monoclonal antibodies against several targets are being investigated for many more neurological diseases, which reflects our advances in understanding the pathogenesis of these diseases. Untangling the molecular mechanisms of disease allows monoclonal antibodies to block disease pathways accurately and efficiently with exceptional target specificity, minimizing non-specific effects. On the other hand, accumulating experience shows that monoclonal antibodies may carry class-specific and target-associated risks. This article provides an overview of different types of monoclonal antibodies and their characteristics and reviews monoclonal antibodies currently in use or under development for neurological disease.

Clinical features and outcomes from the Singapore Sjögren's syndrome study

OBJECTIVE

To study the clinical features, treatment and outcomes of primary Sjögren's Syndrome (pSS) in a Singapore cohort from an outpatient rheumatology clinic.

METHODS

Computerised Physician Order entry records of patients who fulfilled the 2016 ACR-EULAR classification criteria for pSS between 1993 and 2013 were retrospectively analysed.

RESULTS

There were 102 patients, of which 96 (94.1%) were females, and 91 (89.2%) Chinese. Mean age at diagnosis was 49.3 ± 11.8 years, mean disease duration was 9.0 ± 4.6 years. The most common manifestations were keratoconjunctivitis sicca (99.0%), xerostomia (96.1%), arthralgia/arthritis (56.9%). Exocrine glandular enlargement comprised parotidomegaly (28, 27.5%), with concurrent submandibular and lacrimal gland enlargement in one. The nervous system (15.7%) was the most commonly affected internal organ, with peripheral nervous system (peripheral neuropathy, mononeuritis multiplex) involvement more common than central. Hydroxychloroquine was most frequently used (88.2%), followed by methotrexate (7.8%) and azathioprine (6.9%). Pulsed intravenous (IV) methylprednisolone 500 mg/day for 3 days was used in 5 patients followed by oral (4) or IV cyclophosphamide (1) for cardiomyopathy and interstitial lung disease (1), and neurological involvement (4). These comprised neuromyelitis optica, transverse myelopathy, cranial neuropathy, mononeuritis multiplex and/or peripheral neuropathy alone or in combination. Intravenous immunoglobulins (2.0%) was used for sensory neuropathy and mononeuritis multiplex; rituximab (1.0%) in 1 patient for treatment of non-Hodgkin's B-cell lymphoma. There were no deaths.

CONCLUSION

Musculoskeletal manifestations were common, with the nervous system (peripheral more than central) the most common internal organ involved. Lymphoma was uncommon despite up to one-third of the cohort developing glandular enlargement.

Utilization of myositis antibody-specific panel for diagnosis, treatment, and evaluation of disease progression

The idiopathic inflammatory myopathies (IIM) are rare sporadic disorders with an overall annual incidence of approximately 1 in 100,000 and with a higher incidence in women. IIM is an autoimmune process leading to muscle inflammation due to a ‘dysfunctional adaptive immune response evidenced by cell-mediated myocytoxicity, a high prevalence of autoantibodies and overexpression of Major Histocompatibility (MHC) I and II molecules on the muscle sarcolemma’. These autoimmune processes can be appreciated as inflammatory infiltrates in muscle biopsies. Common clinical findings in patients diagnosed with IIM include proximal muscle weakness, elevated creatinine kinase levels, circulating autoantibodies, radiological findings of muscular inflammation, and sometimes edema; in some patients, systemic symptoms such as dysphagia can also be present. Currently, there is no specific IIM classification scheme that incorporates all IIM subtypes; however, the four major IIM subtypes include dermatomyositis, polymyositis, inclusion body myositis, and immune-mediated necrotizing myopathy (IMNM). Two clinical cases are presented in this case report to illustrate a smoldering IIM, antisynthetase syndrome, and a more progressive IIM, anti-signal recognition particle IMNM; highlight the utility of the myositis-specific autoantibody panel for early diagnosis, targeted therapy, and prognosis; and offer primary care providers clues to IIM diagnosis.

Promising and Upcoming Treatments in Myositis

PURPOSE OF REVIEW

To highlight new and emerging treatment targets in myositis.

RECENT FINDINGS

The landscape of novel therapeutics in myositis has vastly changed in the past 5 years. This is largely due to a greater understanding of the pathogenesis of myositis and validation of more robust outcome measures that standardize the ability to assess treatment response. Clinical trials in dermatomyositis are leading the way with ongoing multicenter, international phase 3 clinical trials. Proof-of-concept studies targeting the JAK/STAT pathway have also showed early promise in treating refractory dermatomyositis in adults and children. This review highlights that the future armamentarium of therapeutic drugs will likely be larger and more selective in treating different subgroups of myositis.

SARS-CoV-2 Inflammatory Syndrome. Clinical Features and Rationale for Immunological Treatment

The current pandemic coronavirus, SARS-CoV-2, is a global health emergency because of its highly contagious nature, the great number of patients requiring intensive care therapy, and the high fatality rate. In the absence of specific antiviral drugs, passive prophylaxis, or a vaccine, the treatment aim in these patients is to prevent the potent virus-induced inflammatory stimuli from leading to the acute respiratory distress syndrome (ARDS), which has a severe prognosis. Here, the mechanism of action and the rationale for employing immunological strategies, which range from traditional chemically synthesized drugs, anti-cytokine antibodies, human immunoglobulin for intravenous use, to vaccines, are reviewed.

SARS-CoV-2 Inflammatory Syndrome. Clinical Features and Rationale for Immunological Treatment

The current pandemic coronavirus, SARS-CoV-2, is a global health emergency because of its highly contagious nature, the great number of patients requiring intensive care therapy, and the high fatality rate. In the absence of specific antiviral drugs, passive prophylaxis, or a vaccine, the treatment aim in these patients is to prevent the potent virus-induced inflammatory stimuli from leading to the acute respiratory distress syndrome (ARDS), which has a severe prognosis. Here, the mechanism of action and the rationale for employing immunological strategies, which range from traditional chemically synthesized drugs, anti-cytokine antibodies, human immunoglobulin for intravenous use, to vaccines, are reviewed.