Myositis Disease Activity Research Articles

Predictors of response to intravenous immunoglobulin in patients with dermatomyositis: the ProDERM study.

The phase 3 ProDERM study demonstrated intravenous immunoglobulin (IVIg) was safe and effective in patients with dermatomyositis (DM). This analysis assessed clinical and serological predictors of IVIg response in DM patients from ProDERM. ProDERM was a prospective, randomised, placebo-controlled study of DM patients. For Weeks 0-16, patients received 2.0 g/kg IVIg (Octagam, 10%) or placebo every 4 weeks. Eligible patients entered the open-label extension phase, where all received IVIg to week 40. Univariate and multivariate analyses examined associations between baseline variables and total improvement score (TIS), including myositis disease activity assessment tool (MDAAT; assessing different organ involvement), and myositis-specific and myositis-associated autoantibodies. Ninety-five patients were enrolled. Univariate analyses found no significant association between TIS at week 16 or 40 and age; sex; ethnicity; disease duration/activity; cutaneous, skeletal, gastrointestinal or muscle disease activity; or previous failed or concomitant medications.Multivariate analysis found patients with higher MDAAT cutaneous scores had a better chance of at least minimal TIS improvement. Higher MDAAT pulmonary scores were associated with a lower, but still considerable, chance of improvement. Patients with TIF1-γ antibodies had a better TIS response; however, after controlling for cutaneous disease activity, there was no significant association between antibody classification (including anti-TIF1-γ) and efficacy outcome. IVIg was effective in treating DM patients regardless of demographic features and autoantibody status (for most autoantibodies). Patients with higher cutaneous disease activity and/or anti-TIF1-γ responded best to IVIg, while pulmonary disease activity predicted a lower, but still effective, IVIg response, warranting further investigation. ClinicalTrials.gov, NCT02728752.

Disease activity in patients with idiopathic inflammatory myopathy according to time since diagnosis and positivity to antisynthetase autoantibodies: data from the Myo-Spain registry

ObjectiveTo evaluate the main outcomes of disease activity and their association with other measures of activity, damage, and quality of life in patients with idiopathic inflammatory myopathy (IIM) according to time since diagnosis and positivity to antisynthetase autoantibodies (ASAs).MethodsCross-sectional multicenter study within the Spanish Myo-Spain registry. Cases were classified as incident (≤ 12 months since diagnosis) and prevalent. The main outcomes of disease activity were the Myositis Disease Activity Assessment visual analogue scale (MYOACT), the Manual Muscle Test 8 (MMT-8), physician global activity (PhGA), and extramuscular activity. Other measures of activity, damage, and quality of life included patient global disease activity, MYOACT muscular, creatine phosphokinase, Health Assessment Questionnaire, physician and patient global damage, global damage of the Myositis Damage Index, and the 12-item Short-Form Health Survey (SF-12). We analyzed associations using a multivariate generalized linear model and a simple linear regression model.ResultsA total of 554 patients with different diagnostic subgroups of IIM were included (136 incident and 418 prevalent cases), with 215 ASA-positive patients (58 incident and 157 prevalent cases). All measures of disease activity were higher in the incident cases (p < 0.05), except for MYOACT muscular and creatine phosphokinase, for which no differences were recorded in ASA-positive patients. No differences were found between incident and prevalent cases for measures of damage. Values for the physical component of the SF-12 were higher in the prevalent cases (p < 0.05). The multivariate model was initially significant overall for the main activity outcomes. Positivity to ASAs was positively and negatively associated with the MYOACT index and MMT-8, respectively (p < 0.05), although no association was recorded with PhGA and extramuscular activity. Prevalent cases were negatively associated with the main outcomes of activity, except with MMT-8, for which the association was positive (p < 0.05).ConclusionsThe main activity outcomes validated in polymyositis and dermatomyositis could also be used in other subtypes of IIM, such as antisynthetase syndrome. Recent diagnosis is associated with greater disease activity, as assessed based on these activity outcomes. PhGA and extramuscular activity are not modified by ASA positivity, thus supporting their preferred use for assessing treatment response in IIM with ASAs.

Inflammatory Myopathies and Autoimmune Gluten-related Disorders: A Scoping Review of Pathophysiological Interconnections and Hypothesis.

Anecdotal reports describe patients with concurrent idiopathic inflammatory myopathy (IIM) and celiac disease (CeD) in whom the introduction of a gluten-free diet led to dramatic improvement of myositis. We first systematically reviewed all peer-reviewed publications on concomitant IIM and duodenal biopsy-verified CeD. The collected evidence was suggestive of associations between myositis disease activity and gluten exposure in some patients with IIM-CeD. To investigate possible explanations for the observations, an exploratory review of basic pathophysiological relationships between IIM and gluten-related disorders was performed using a combined strategy of systematic and non-systematic literature searches and forward and backward citation tracking. The investigations revealed close pathophysiological associations between IIM and the autoimmune gluten-related disorders CeD, dermatitis herpetiformis, and gluten ataxia. Common traits include shared genetic predisposition through HLA-DQ2.5/-DQ8, disease activity-associated autoantibodies, histopathological parallels with inflammatory cell infiltrates, and similarly distributed structural homologous transglutaminases (TGs). HLA-DQ2.5-restricted gluten-specific CD4+ T cells of a rare, uniform phenotype are reported in CeD and connective tissue disease. Expanded T-cell clones with identical phenotypes and CDR3β motifs indicate the presence of a continuous, antigen-driven T-cell response. The investigations revealed that the main components involved in the adaptive immune response in the CeD gut may be present in HLA-DQ2.5+/-DQ8+ IIM muscle. The collected evidence supports the notion that in some genetically predisposed patients with IIM, gluten may act as an exogenous antigen driving myositis. Further Research/Clinical Implications: To test the above hypothesis, clinical trials combined with immunological studies are needed. Meanwhile, the inclusion of HLA-DQ typing may be justified, and subsequent small-intestinal biopsies in HLA-DQ2.5/8+ individuals with IIM.

Adenosine A2B receptor activation regulates the balance between T helper 17 cells and regulatory T cells, and inhibits regulatory T cells exhaustion in experimental autoimmune myositis.

Idiopathic inflammatory myopathy (IIM) is a systemic autoimmune disease characterized by skeletal muscle involvement. This study aimed to investigate the role of adenosine receptor signalling pathways in the development of experimental autoimmune myositis (EAM). An ecto-5'-nucleotidase (CD73) inhibitor, adenosine receptor agonists, a hypoxia-inducible factor-1α (HIF-1α) inhibitor or a vehicle were administered to control and EAM mice. Murine splenic CD4+ or regulatory T cells (Tregs) were isolated using magnetic beads and subsequently stimulated with an adenosine A2B receptor agonist, a HIF-1α inhibitor, or vehicle in vitro. In cross-sectional studies, we collected 64 serum samples (69% female, 49±9years), 63 peripheral blood samples (70% female, 50±11years), and 34 skeletal muscle samples (71% female, 63±6years) from patients with IIM. Additionally, 35 serum samples and 30 peripheral blood samples were obtained from age- and sex-matched healthy controls, and six quadriceps muscle samples were collected from patients with osteoarthritis to serve as the normal group. Patients with IIM exhibited increased CD73 [dermatomyositis (DM), polymyositis (PM): P<0.01; immune-mediated necrotizing myopathy (IMNM): P<0.0001] and adenosine deaminase (ADA) expression (DM: P<0.001; PM, IMNM: P<0.0001) in the skeletal muscles, and serum ADA levels [56.7 (95% CI: 53.7, 58.7) vs. 198.8 (95% CI: 186.2, 237.3) ng/μL, P<0.0001]. Intervention with a CD73 inhibitor exacerbated (P=0.0461), whereas adenosine receptor agonists (A1: P=0.0009; A2B: P<0.0001; A3: P=0.0001) and the HIF-1α inhibitor (P=0.0044) alleviated skeletal muscle injury in EAM mice. Elevated expression of programmed cell death protein-1 (PD1: P=0.0023) and T-cell immunoglobulin and mucin-domain containing-3 (TIM3: P<0.0001) in skeletal muscles of patients with IIM were correlated with creatine kinase levels (PD1, r=0.7072, P<0.0001; TIM3, r=0.4808, P=0.0046). PD1+CD4+ (r=0.3243, P=0.0115) and PD1+CD8+ (r=0.3959, P=0.0017) T cells were correlated with Myositis Disease Activity Assessment Visual Analogue Scale scores (muscle) in IIM. The exhausted Tregs were identified in the skeletal muscles of patients with IIM. Activation of the A2B adenosine receptor downregulated HIF-1α (protein or mRNA level, P<0.01), resulting in decreased T helper cell 17 (Th17) (13.58% vs. 5.43%, P=0.0201) and phosphorylated-signal transducer and activator of transcription 3 (p-STAT3)+ Th17 (16.32% vs. 6.73%, P=0.0029), decreased exhausted Tregs (PD1+ Tregs: 53.55% vs. 40.28%, P=0.0005; TIM3+ Tregs: 3.93% vs. 3.11%, P=0.0029), and increased Tregs (0.45% vs. 2.89%, P=0.0006) in EAM mice. The exhausted T cells may be pathogenic in IIM,andthe activation of adenosine A2B receptor signalling pathway can regulate Th17/Treg balance and inhibit Tregsexhaustion, thereby slowing EAM disease progression.

The impact of pain on daily activities in patients with idiopathic inflammatory myopathies: Report from the OMERACT myositis working group

International focus groups with patients with idiopathic inflammatory myopathies (IIM) conducted by the OMERACT Myositis Working Group over the years demonstrated the pain as an important symptom experienced by these patients. In this study, we aimed to examine the frequency and degree of pain interference, the aspects of daily life impacted by pain, and the factors associated with pain interference in adults with IIM. This was a prospective observational study with two visits. The patients who fulfilled the probable/definite IIM (ACR/EULAR Myositis Classification Criteria) were enrolled. Pain interference was assessed with PROMIS pain interference form (6a). Myositis core set measures and PROMIS fatigue (7a) and physical function (8b) were obtained at both visits. Logistic regression and linear mixed models were performed to assess the association between pain interference and other parameters. A total of 129 patients with IIM (60 % females) were recruited from U.S., South Korea, Netherlands, Sweden, and Australia. Approximately 71 % reported pain interference. The patients in the greater pain interference group were more likely to be female, had significantly worse patient/physician global disease activity, fatigue, and physical function than those in the lower pain interference group. The most commonly impacted life aspect was household chores. Manual muscle testing, patient/physician global disease activity, fatigue, and physical function were all significantly associated with pain interference score >60. The majority of the patients with IIM experience the impact of pain on their daily activities, particularly household chores. Myositis disease activity, duration, and subtype could be associated with greater pain interference.

Magnetic resonance imaging T2 mapping could reflect disease status in patients with dermatomyositis or polymyositis

This study aimed to explore the value of magnetic resonance imaging (MRI) T2 mapping in the assessment of dermatomyositis (DM) and polymyositis (PM). Thirty-three confirmed cases (myosin group) and eight healthy volunteers (healthy control group) at the Department of Rheumatology and Immunology, the First Affiliated Hospital of Kunming Medical University, from October 2016 to December 2017, were collected and analyzed. Multiple parameters of the myosin group were quantified, including creatine kinase (CK), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complement C3, and complement C4. Disease status was evaluated using a panel of tools: myositis disease activity assessment tool-muscle (MDAAT-muscle), myositis disease activity assessment tool-whole (MDAAT-all), health assessment questionnaire (HAQ), medical outcomes study health survey short form-36 item (SF-36), hand muscle strength test (MMT-8) score, and MRI T2 mapping of muscle (22 muscles in the pelvis and thighs) T2 values. The results showed that in the myositis group, the measurements for CK, ESR, CRP, complement C3, and complement C4 were 457.2 (165.6, 1 229.2) IU/L, 20 (10, 42) mm/1h, 3.25 (2.38, 10.07) mg/L, 0.90 (0.83, 1.06) g/L, and 0.18 (0.14, 0.23) g/L, respectively. The scores for MMT-8, MDAAT-muscle, MDAAT-all, HAQ, and SF-36 were 57.12±16.23, 5.34 (4.00, 6.00), 34.63±12.62, 1.55 (0.66, 2.59), and 44.66±7.98, respectively. T2 values were significantly higher in all 22 muscles of the pelvis and thighs of patients with DM or PM compared with the healthy controls [(54.99±11.60)ms vs. (36.62±1.66)ms, P<0.001], with the most severe lesions in the satrorius, iliopsoas, piriformis, gluteus minimus, and gluteus medius muscles. The total muscle T2 value in the myositis group was positively correlated with CK, MDAAT-muscle, MDAAT-all, and HAQ (r=0.461, 0.506, 0.347, and 0.510, respectively, all P<0.05). There was a negative correlation between complement C4, SF-36, and MMT-8 scores (r=-0.424, -0.549, and -0.686, respectively, all P<0.05). Collectively, the findings from this study suggest that MRI T2 mapping can objectively reflect the disease status of DM and PM.

Evaluation of the effectiveness of using prednisolone, tacrolimus, and intravenous immunoglobulin combination therapy on immune-mediated necrotizing myopathy-A non-randomized, observational research.

To recruit immune-mediated necrotizing myopathy (IMNM) patients with extramuscular manifestations who were refractory to initial therapy with either monotherapy with prednisolone or dual therapy with prednisolone and immunosuppressants. These patients subsequently received a combination of prednisolone, tacrolimus, and intravenous immunoglobulin (IVIG), and the efficacy of this treatment regimen was assessed in patients with IMNM. ①Clinical data and treatment measures are as follows: This study enrolled IMNM patients who were treated at the Neurology Department of the First Medical Center of PLA General Hospital from April 2020 to May 2023. These patients received a combination therapy of prednisolone, tacrolimus, and IVIG. ②Observational indicators included manual muscle test for 8 groups of muscles (MMT-8), muscle enzyme levels (creatine kinase (CK), lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST)), and myositis disease activity assessment tool (MDAAT). This study enrolled eight patients. All observational indicators declined after treatment compared to before treatment, and these changes were statistically significant. Moreover, extramuscular manifestations also ameliorated compared to before treatment. The combination therapy of prednisolone, tacrolimus, and IVIG has demonstrated favorable efficacy in IMNM and broadened the treatment options for this disease. However, the results still require further validation by large-scale and randomized controlled studies.

Pain is common in myositis and associated with disease activity.

Understanding pain in myositis remains challenging. This study aimed to assess patient-reported pain and its correlation with myositis core set measures (CSMs), patient-reported outcomes (PROs) and functional measures. Fifty subjects underwent baseline, 3-month and 6-month assessments, evaluating myositis CSMs, functional measures and PROs. Pain was measured using three methods: (i) a 10-cm visual analogue scale, (ii) the pain score from the HAQ Disability Index and (iii) the Short Form 36 survey pain questions. Correlations between disease activity measures and pain were examined at baseline, and changes in both were assessed at 6 months, along with longitudinal change of pain. The change in pain was also correlated with the published 2016 ACR/EULAR myositis response criteria, physician/patient's assessment of change. Nearly half of patients (45%) reported moderate to severe pain in all three pain scales, with higher severity of pain in PM/necrotizing myopathy subset. At baseline, pain severity showed a strong correlation with most CSMs, PROs and functional outcomes in all three pain scales, and similar trends were noted for change in pain at the 6 months. On longitudinal analysis, the physical function scores and fatigue showed strong correlation with pain. Pain improved in myositis patients with improvement in disease activity over time. Pain is common in myositis and is associated with multiple measures of disease activity, PROs and functional outcomes in myositis. Most importantly pain improves with improvement in disease activity. SF-36 pain questions have good psychometric properties.

YKL-40 serum levels are predicted by inflammatory state, age and diagnosis of idiopathic inflammatory myopathies

YKL-40 increase according to the aging process, and its functions have been associated with tissue remodeling and systemic inflammation. In Rheumatoid Arthritis (RA) it has been proposed as a possible biomarker of activity and severity, however; in the field of idiopathic inflammatory myopathies (IIM) the role of YKL-40 in IIM is not clear. Thus, we aimed to evaluate if there is an association between the serum levels and muscle tissue expression of YKL-40 with age, IIM phenotype, muscle strength and myositis disease activity. The main finding was that age is the most important variable that affects the YKL-40 serum levels. In muscle biopsy, we observed that YKL-40 is mainly expressed in infiltrating lymphoid cells than in muscle tissue. Using ANCOVA according to the b-coefficients, YKL-40 serum levels are predicted by inflammatory state, age, and IIM diagnosis.

Efficacy of intravenous immunoglobulins (IVIg) in improving skin symptoms in patients with dermatomyositis: a post-hoc analysis of the ProDERM study

Dermatomyositis (DM) is a rare autoimmune disease characterized by skin involvement, with or without proximal muscle weakness. Recently, following the ProDERM study, intravenous immunoglobulin (IVIg) was approved for treatment of DM. Until ProDERM evidence from large, placebo-controlled studies supporting its use for dermatological symptoms, was lacking. Here we present efficacy data from ProDERM of IVIg versus placebo for treatment of the cutaneous aspect of DM. ProDERM was a double-blind, randomized, multicenter, Phase 3 study. In the First Period (Weeks 0-16), adults with active DM received 2.0g/kg IVIg (Octagam 10%; Octapharma AG) or placebo every 4 weeks. In the open-label Extension Period (Weeks 16-40), all patients received IVIg for 6 additional cycles. Cutaneous disease was assessed using measures including modified cutaneous DM disease area and severity index activity (CDASI-A) and damage (CDASI-D) scores, and myositis disease activity assessment tool (MDAAT) including visual analogue scale (VAS). This trial is registered with ClinicalTrials.gov, NCT02728752. The study took place from February 2017 to November 2019. 95 patients received IVIg (N=47) or placebo (N=48) in the First Period. Together, 664 IVIg infusion cycles were administered (median dose, 2.0g/kg). At Week 16, mean CDASI-A change from baseline was-9.36 (95% CI:-12.52,-6.19) in the IVIg group versus-1.16 (-3.32, 0.99) in placebo group (p<0.0001). At the end of the Extension Period, mean changes from baseline were-10.44 (95% CI:-13.94,-6.94) and-10.03 (-13.12,-6.94), respectively. Similar changes were seen for CDASI-D and VAS of MDAAT. These observations were seen regardless of baseline disease severity. ProDERM is the first large prospective, randomized trial to demonstrate the efficacy of IVIg to improve the cutaneous manifestations of DM. IVIg treatment significantly improved dermatological symptoms in patients with DM, regardless of disease severity before treatment, suggesting that IVIg is effective for even the most severe cutaneous DM. This study was sponsored by Octapharma Pharmazeutika Produktionsges m.b.H.

Observational longitudinal study to assess the outcome of patients with idiopathic inflammatory myositis using validated tools.

There have been major changes in the classification and treatment of patients with idiopathic inflammatory myositis (IIM) in the last 2 decades. A major challenge is to identify the parameters that can affect the outcome and prognosis of these patients. Here, we have longitudinally followed a well-characterized cohort of IIM patients in a rheumatology center and reported the outcome using the validated tools. Patients with a clinical diagnosis of IIM and a follow-up duration of greater than 2 years were prospectively included in the study. The duration of the study was 6 years: July 2016-July 2022. Clinical details and follow-up were recorded using pro-formas and outcomes were noted using validated tools. Ethics approval and written informed consent were taken. Forty patients had a clinical diagnosis of IIM. Mean follow-up duration was 43.8 (15) months. Out of 40 patients, 32 (80%) achieved remission (8 patients each were off corticosteroid and off treatment for >6 months), 5 (12%) expired and 3 (8%) had active disease. Disease course was non-relapsing in 22/35 (73%) patients. Mean manual muscle testing-8 score (n = 29) and myositis disease activity assessment tool score (n = 35) at the final visit were 75.6 (6.8) and 0.048 (0.07) respectively. Thirteen patients had damage (37%). Patients with disease duration >1 year at the time of presentation were more likely to develop chronic-continuous disease course (P = .023, odds ratio [OR] = 7.6), more frequently required second-line or third-line immunosuppression (P = .001, OR = 24) with higher myositis damage index score (p = .0002, OR = 47). IIM patients had good outcomes with the majority achieving remission and near-complete muscle recovery. However, the patients presenting late to the rheumatologists were more likely to have smoldering disease, more immunosuppressive medicines, and greater accumulated damage.

First study demonstrating speckle tracking echocardiography has prognostic value in patients with idiopathic inflammatory myopathies.

To measure left ventricular (LV) global longitudinal strain (GLS) using speckle tracking echocardiography in idiopathic inflammatory myopathy (IIM) patients and to determine whether the LV GLS predicts outcomes in those patients. Prospective study consisted of a cross-sectional phase with 61 IIM patients and 32 individuals without IIM and longitudinal phase, in which patients were divided into two subgroups: 26 with reduced LV GLS and 35 with normal LV GLS; patients were followed for a mean of 25months, and the occurrence of cardiovascular events and criteria for IIM activity were compared. The mean LV GLS (18.5 ± 2.9% vs. 21.6 ± 2.5%; p < 0.001) and right ventricle free wall strain (21.9 ± 6.1% vs. 27.5 ± 4.7%; p < 0.001) were lower in patients than in controls. The mean N-terminal pro B-type natriuretic peptide level was higher in patients than in controls. There were no differences regarding other cardiac involvement. Anti-Jo1 antibody was associated with general electrocardiographic abnormality and LV diastolic dysfunction. The subgroup with reduced GLS progressed with higher mean creatine phosphokinase, myositis disease activity assessment visual analogue scales, the physician's and patient's visual analogue scales, the health assessment questionnaire, and a higher proportion of relapses than the subgroup with normal GLS. There was no difference between the subgroups regarding cardiovascular events. The LV GLS appears to be useful for evaluating patients with IIM. Abnormal values are associated with more frequent relapses and increased disease activity during follow-up.

Increased serum soluble interleukin-2 receptor levels in dermatomyositis are associated with Th17/Treg immune imbalance.

Dermatomyositis (DM) represents a multifaceted chronic inflammatory myopathy, primarily manifesting as progressive deterioration of muscular and cutaneous tissues. Despite an incomplete comprehension of DM's etiology and pathogenesis, current evidence implicates the involvement of T lymphocyte infiltration, extensive cytokine release, myositis-specific antibodies, and myositis-associated antibodies in disease development. Serum soluble interleukin-2 receptor (sIL-2R) frequently serves as a marker for T cell activation; however, its role remains elusive. Consequently, this investigation sought to elucidate the association between sIL-2R levels, peripheral blood lymphocyte subset counts, and related cytokines in DM patients, with the aim of uncovering the intricate mechanisms underlying DM and establishing a theoretical foundation for the implementation of precise, targeted, individualized immunomodulatory therapy. In this study, a cohort of 60 dermatomyositis (DM) patients, comprising 32 with inactive DM and 28 with active DM, was enrolled and stratified into inactive and active groups based on the Myositis Disease Activity Visual Analogue Scale (MYOACT). Flow cytometry was employed to quantify the absolute counts of peripheral lymphocyte subsets and CD4+T cell subsets in each group, while a flow cytometry bead array was utilized to measure serum cytokine levels. In a comparative analysis between healthy individuals and patients diagnosed with DM, we observed a marked elevation in serum sIL-2R concentrations (P < 0.001) and T-helper 17 cell/regulatory T cell (Th17/Treg) ratios (P < 0.01) within the latter group. A positive correlation was identified between serum sIL-2R levels and various parameters, including ESR, CRP, VAS, AST, CKMB, LDH, HBDH, PT, APTT, DDi, IL-6, IL-10, and IFN-γlevels (P < 0.05). In contrast, serum sIL-2R levels demonstrated a negative correlation with LY, HGB, ALB, Th17 cell populations, and Th17/Treg cell ratios (P < 0.05). Employing multivariate logistic regression, we identified serum sIL-2R concentrations as an independent risk factor for both disease activity and hepatic involvement in DM patients. Moreover, receiver operating characteristic (ROC) curve analyses revealed that serum sIL-2R levels significantly contributed to the differentiation of disease activity and the detection of liver involvement in DM patients, with areas under the ROC curve (AUC) of 0.757 (95% CI 0.630-0.884, P = 0.001) and 0.826 (95% CI 0.717-0.935, P < 0.001), respectively. This study highlights the potential utility of serum sIL-2R levels as a valuable biomarker for assessing disease activity and liver involvement in dermatomyositis. Elevated serum concentrations of sIL-2R were observed in patients with DM, exhibiting significant associations with Th17 cell populations and Th17/ Treg ratios. These findings indicate that sIL-2R may be implicated in the immunopathogenesis of DM, thereby warranting further investigation to elucidate its role in the disease process.

Plasma pentraxin 3 in idiopathic inflammatory myopathies: a possible new biomarker of disease activity.

Pentraxin-3 (PTX3) is a component of humoral innate immunity with essential functions both in promotion and resolution of inflammation. We aimed to study the PTX3 in the plasma and in the muscle of patients with idiopathic inflammatory myopathies (IIM) and whether PTX3 may correlate with disease activity. Plasma PTX3 levels were assessed in 20 patients with IIMs, 10 dermatomyositis (DM), and 10 polymyositis (PM), compared to 10 patients with rheumatoid arthritis (RA) and 10 healthy donors (HDs) aged, sex, and body mass index matched. Disease activity in IIMs was assessed by Myositis Disease Activity Assessment Visual Analog Scale (MYOACT), while disease activity score on 28 joints (DAS28) was used for RA patients. Muscle histopathology and immunohistochemical (IHC) analyses were also performed. Mean plasma PTX3 levels were significantly higher in IIM patients than HDs (518 ± 260 pg/ml vs. 275 ± 114 pg/ml, P = 0.009). Linear regression analysis adjusted for age, sex, and disease duration showed a direct correlation between PTX3 and CPK levels (β: 0.590), MYOACT (β: 0.759), and physician global assessment of disease activity (β: 0.832) in IIMs. No association between PTX3 levels and DAS28 was found in RA. Global PTX3 pixel fraction was higher in IIM than HDs muscle, but a lower PTX3 expression was found in perifascicular areas of DM and in myofibers with sarcolemmal staining for membrane attack complement. PTX3 plasma levels were increased in IIMs and correlated with disease activity suggesting a possible role as biomarker of disease activity. PTX3 showed a different distribution in DM or PM muscle.

Type I interferon score is associated with the severity and poor prognosis in anti-MDA5 antibody-positive dermatomyositis patients.

To investigate the clinical significance of the interferon (IFN) score, especially the IFN-I score, in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (anti-MDA5+ DM). We enrolled 262 patients with different autoimmune diseases, including idiopathic inflammatory myopathy, systemic lupus erythematosus, rheumatoid arthritis, adult-onset Still's disease, and Sjögren's syndrome, as well as 58 healthy controls. Multiplex quantitative real-time polymerase chain reaction (RT-qPCR) using four TaqMan probes was used to evaluate type I IFN-stimulated genes (IFI44 and MX1), one type II IFN-stimulated gene (IRF1), and one internal control gene (HRPT1), which were used to determine the IFN-I score. The clinical features and disease activity index were compared between the high and low IFN-I score groups in 61 patients with anti-MDA5+ DM. The associations between laboratory findings and the predictive value of the baseline IFN-I score for mortality were analyzed. The IFN score was significantly higher in patients with anti-MDA5+ DM than in healthy controls. The IFN-I score was positively correlated with the serum IFN-α concentration, ferritin concentration, and Myositis Disease Activity Assessment Visual Analogue Scale (MYOACT) score. Compared with patients with a low IFN-I score, patients with a high IFN-I score showed a higher MYOACT score, C-reactive protein concentration, aspartate transaminase concentration, ferritin concentration, plasma cell percentage, and CD3+ T-cell percentage, as well as lower lymphocyte, natural killer cell, and monocyte counts. The 3-month survival rate was significantly lower in patients with an IFN-I score of >4.9 than in those with an IFN-I score of ≤4.9 (72.9% vs. 100%, respectively; P = 0.044). The IFN score, especially the IFN-I score, measured by multiplex RT-qPCR is a valuable tool to monitor disease activity and predict mortality in patients with anti-MDA5+ DM.

Coordinated local RNA overexpression of complement induced by interferon gamma in myositis

Complement proteins are deposited in the muscles of patients with myositis. However, the local expression and regulation of complement genes within myositis muscle have not been well characterized. In this study, bulk RNA sequencing (RNAseq) analyses of muscle biopsy specimens revealed that complement genes are locally overexpressed and correlate with markers of myositis disease activity, including the expression of interferon-gamma (IFNγ)-induced genes. Single cell and single nuclei RNAseq analyses showed that most local expression of complement genes occurs in macrophages, fibroblasts, and satellite cells, with each cell type expressing different sets of complement genes. Biopsies from immune-mediated necrotizing myopathy patients, who have the lowest levels of IFNγ-induced genes, also had the lowest complement gene expression levels. Furthermore, data from cultured human cells showed that IFNγ upregulates complement expression in macrophages, fibroblasts, and muscle cells. Taken together, our results suggest that in myositis muscle, IFNγ coordinates the local overexpression of complement genes that occurs in several cell types.

Urine proteomics by mass spectrometry identifies proteins involved in key pathogenic pathways in patients with juvenile dermatomyositis.

To identify and validate biomarkers in JDM patients using a multiplexing tandem mass tag urine proteome profiling approach. First morning void urine samples were collected from JDM patients (n = 20) and healthy control subjects (n = 21) and processed for analysis using a standardized liquid chromatography-tandem mass spectrometry approach. Biomarkers with significantly altered levels were correlated with clinical measures of myositis disease activity and damage. A subset of candidate biomarkers was validated using commercially available ELISA kits. In total, 2348 proteins were detected in the samples, with 275 proteins quantified across all samples. Among the differentially altered proteins, cathepsin D and galectin-3 binding protein were significantly increased in the urine of JDM patients (adjusted P < 0.05), supporting previous findings in myositis patients. These two candidate biomarkers were confirmed with ELISAs. Cathepsin D positively correlated with Myositis Damage Index (r = 0.57, P < 0.05) and negatively correlated with the Childhood Myositis Assessment Scale (r = -0.54, P < 0.05). We also identified novel JDM candidate biomarkers involved with key features of myositis, including extracellular matrix remodelling proteins. This study confirmed the presence of several proteins in the urine of JDM patients that were previously found to be elevated in the blood of myositis patients and identified novel candidate biomarkers that require validation. These results support the use of urine as a source for biomarker development in JDM.

The relationship between platelet distribution width and disease activity in patients with polymyositis.

Muscle enzymes are an indicator of ongoing muscle damage and disease activity in patients with idiopathic inflammatory myopathy. Although platelet-related parameters have been shown to be useful as markers of disease activity in autoimmune diseases, the relationship between platelet distribution width (PDW) and disease activity has not been previously studied in polymyositis. We aimed to determine the relationship between PDW and disease activity in patients with polymyositis. Twenty-seven patients with polymyositis and thirty healthy controls were included in the study. Disease activity was evaluated using the myositis disease activity assessment Visual Analogue Scale (MYOACT) and the Myositis Intention to Treat Index (MITAX). The relationship between PDW and disease activity was evaluated using Pearson's or Spearman's correlation and reliability was assessed using correlation coefficients. The mean platelet volume (MPV) and plateletcrit (PCT) were significantly higher and PDW was significantly lower in patients with polymyositis compared to the control group. The mean PDW levels were lower in patients with constitutional symptoms and arthralgia/arthritis (p < 0.005). Although PDW levels were lower in patients with mechanical hand, lung involvement, or dysphagia compared to patients without, there was no statistically significant difference between them. Platelet distribution width was found to be negatively correlated with disease activity. We found that PDW was negatively correlated with MYOACT and MITAX, widely used tools in assessing the disease activity of polymyositis. Based on this, PDW may be utilized as a non-invasive potential index to assess disease activity in patients with polymyositis.

Clinical course of idiopathic inflammatory myopathies in COVID-19 pandemic: a single-center experience.

Aim: To evaluate the clinical course of idiopathic inflammatory myopathy (IIM) patients in COVID-19 pandemic, and to assess the COVID-19 outcomes in infected IIM patients. Materials & methods: In this study, 39 patients were evaluated retrospectively. Myositis disease activity, myositis damage index, depression, fatigue, active medical treatment, drug compliance and SARS-CoV-2 PCR test results in COVID-19 pandemic were collected. Results: Fourteen of these patients (35%) were detected to have a positive SARS-CoV-2 PCR test. The demographic and clinical characteristics, active medical treatment, disease activity, depression and fatigue of the patients who had undergone or not SARS-CoV-2 were similar. Conclusion: Our results have shown that although prevalence of COVID-19 seems to be increased in IIM patients under immunosuppressive treatment, hospitalization rates were lower and no intensive care unit admissions or deaths were observed.

Using multi-parametric quantitative MRI to screen for cardiac involvement in patients with idiopathic inflammatory myopathy

Idiopathic inflammatory myopathies (IIM) is a group of heterogeneous autoimmune systemic diseases, which not only involve skeletal muscle but also myocardium. Cardiac involvement in IIM, which eventually develops into heart failure, is difficult to identify by conventional examinations at early stage. The aim of this study was to investigate if multi-parametric cardiac magnetic resonance (CMR) imaging can screen for early cardiac involvement in IIM, compared with clinical score (Myositis Disease Activity Assessment Tool, MDAAT). Forty-nine patients of IIM, and 25 healthy control subjects with comparable age-range and sex-ratio were enrolled in this study. All subjects underwent CMR examination, and multi-slice short-axis and 4-chamber cine MRI were acquired to evaluate biventricular global circumferential strain (GCS) and global longitudinal strain (GLS). Native T1 and T2 mapping were performed, and post-contrast T1 mapping and LGE were acquired after administration of contrast. A CMR score was developed from native T1 mean and T2 mean for the identification of cardiac involvement in the IIM cohort. Using contingency tables MDAAT and CMR were compared and statistically analyzed using McNemar test. McNemar’s test revealed no significant difference between CMR score and MDAAT (p = 0.454). CMR score had potential to screen for early cardiac involvement in IIM patients, compared to MDAAT.