Comparison of rituximab efficacy in treatment-naive and refractory inflammatory myopathies: experiences from a tertiary care centre.

OBJECTIVES: To find out if Rituximab (RTX) is effective in "treatment naive" idiopathic inflammatory myopathies (IIM), and whether there could be differential treatment responses between the "treatment naive" and treatment "refractory" IIM. METHODS: Data obtained from a prospectively maintained database comprising patients with IIM treated with rituximab. Patient details were obtained at baseline, 3-months, 6-months intervals, and subsequent follow up visits. Treatment response was categorised as improved, worsening, or stable based on manual muscle testing (MMT8) scores, patient global and physician global improvement (PtGA and PGA) for skin and joint symptoms improvement and spirometry at 6 months. The time to clinical improvement and remission were noted and survival analysis curves were constructed. RESULTS: 60 patients with IIM (including 18 with anti-SRP myopathy) were included, out of which 33 who received RTX were treatment naïve. The remaining 27 were started on rituximab for refractory myopathy. Mean age was 39 years (SD12.58) in "treatment-naive" group and 43 years (SD 12.12) in "refractory" group. At 6 months of follow up, 48/55 (87%) patients showed response, 31/31 (100%) in "treatment-naive" and 17/24 (70%) in "refractory" cases, p 0.006*. In refractory group, 7 (29%) had stable disease. The mean changes in MMT8 were significantly more in the "treatment-naive" treatment group (13.41(SD 7.31) compared with "refractory" IIM 8.33 (SD 7.92) (p= 0.017*). Majority of patients were able to reduce dose below 5 mg/day before 6 months. No major adverse events were reported over the median follow-up of 24 (IQR 36) months. CONCLUSIONS: Rituximab is effective and safe across the spectrum of IIM. Early use in disease is associated with better outcomes.

Assessing the sensitivity and specificity of myositis-specific and associated autoantibodies: a sub-study from the MyoCite cohort.

OBJECTIVES: Myositis-specific and associated autoantibodies are important biomarkers in routine clinical use. We assessed local testing performance for myositis autoantibodies by comparing line immunoassay (LIA) to protein radio-immunoprecipitation and identifying clinical characteristics associated with each myositis autoantibody in the MyoCite cohort. METHODS: Serum samples from patients within the MyoCite cohort, a well-characterized retro-prospective dataset of adult and juvenile idiopathic inflammatory myopathy (IIM) patients in Lucknow, India (2017-2020), underwent LIA at Sanjay Gandhi Postgraduate Institute of Medical Science (SGPGIMS), Lucknow. Immunoprecipitation of 147 IIM patients' serum samples (125 adult-onset, 22 juvenile-onset) was conducted at the University of Bath, with researchers blind to LIA results. LIA performance was assessed against immunoprecipitation as the reference standard, measuring sensitivity, specificity and inter-rater agreement. Univariate and multivariate logistic regression determined clinical associations for specific myositis-specific autoantibodies. RESULTS: Immunoprecipitation identified myositis autoantibodies in 56.5% (n = 83) of patient samples, with anti-Jo1 (n = 16; 10.9%) as the most common, followed by anti-MDA5 (n = 14, 9.5%). While LIA showed good agreement for anti-Jo1, anti-PL7 and anti-PL12 (Cohen's κ 0.79, 0.83 and 1, respectively), poor agreement was observed in other subgroups, notably anti-TIF1γ (Cohen's κ 0.21). Strongly positive samples, especially in myositis-specific autoantibodies, correlated more with immunoprecipitation results. Overall, 59 (40.1%) samples exhibited non-congruence on LIA and immunoprecipitation, and κ values for LIAs for anti-TIF1γ, anti-Ku, anti-PmScl, anti-Mi2 and anti-SAE ranged between 0.21 and 0.60. CONCLUSION: While LIA reliably detected anti-Jo1, anti-PL7, anti-PL12, anti-MDA5 and anti-NXP-2, it also displayed false positives and negatives. Its effectiveness in detecting other autoantibodies, such as anti-TIF1γ, was poor.

Kikuchi-Fujimoto Disease Preceding Overlap Syndrome of Sjögren's Syndrome and Systemic Lupus Erythematosus: Literature Review Based on a Case Report.

Kikuchi-Fujimoto disease (KFD) is a benign, self-limiting histiocytic necrotizing lymphadenitis systemic disorder with unknown etiology. KFD has been known for half a century, but difficulties in distinguishing it remain. Its diagnostic significance is related to the increasing prevalence of KFD with autoimmune diseases in various timeframes. Systemic lupus erythematosus (SLE) is the most prevalent autoimmune connective tissue disease (AICTD) appearing alongside KFD. An 18-year-old female presented with acute muscle weakness, shortness of breath, fever, and significant weight loss for 5 months before admission. Pain and morning joint stiffness had been felt for 9 months. One year ago, she lumped her right neck and was diagnosed with KFD from the excision biopsy and immunohistochemical staining (CD68). Creatine-kinase enzymes and C-Reactive protein were elevated with a high anti-Ku and anti-Jo-1 negative level. There was a low level of complements, high anti-nuclear antibody titer, with positive anti-SS-A. Sialometry and Schirmer test showed reduced salivary and lacrimal gland production. We diagnosed this patient as having an overlap syndrome preceded by KFD. The AICTD involved was Sjögren's syndrome and SLE. Although KFD is considered a self-limiting disease, its occurrence should be noticed regarding the possibility of other autoimmune conditions. KFD usually coincides with AICTD, although it could also precede or occur afterward. This case is reported to raise awareness of the overlap syndrome preceded by KFD.

Immune cell profiles of idiopathic inflammatory myopathy patients expressed anti-aminoacyl tRNA synthetase or anti-melanoma differentiation-associated gene 5 autoantibodies.

BACKGROUND: Patients with idiopathic inflammatory myopathy (IIM) often express a different type of myositis-specific autoantibodies (MSAs), each associated with different clinical symptoms. Understanding the immunopathogenesis of various IIM subgroups can help improve the diagnosis and prognosis of IIM patients with different MSAs. However, the immune cell profiles of these IIM patients with anti-aminoacyl tRNA synthetase (ARS) or anti-melanoma differentiation-associated gene 5 (MDA5) autoantibodies remain unclear. We focused on the immune cell profiles of IIM patients with anti-ARS or anti-MDA5 autoantibodies. RESULTS: The peripheral blood from IIM patients with anti-MDA5 autoantibody (MDA5 + group, n = 24) or one of the anti-ARS autoantibodies (ARS + group, n = 40) autoantibodies, and healthy controls (HC group, n = 60) were collected and examined. We found that IIM patients had a lower CD3 T cell population compared to the HC group. IIM patients showed a significantly lower TN cell population and a higher TEMRA cell population. Higher Th17 and Treg cell populations were found in these IIM patients than in the HC group. In these IIM patients, the MDA5 + group exhibited the higher percentages of Th17 and Treg cells than the ARS + group. It is noteworthy that the percentage of Th1 cells in the survival subgroup was higher than in the death subgroup in IIM patients with ARS + or MDA5 + . Furthermore, in the MDA5 + group, the percentage of Treg cells was higher in the survival subgroup compared to the death subgroup. CONCLUSIONS: Our study demonstrated that elevated Th1 may be a good prognostic indicator in IIM patients with ARS + or MDA5 + . Elevated Treg may also help predict a good prognosis in MDA5 + IIM patients. However, more large-scale studies and clinical samples are needed to verify the significance of Th1 and Treg cell subsets in clinical outcomes for these IIM patients with ARS + or MDA5 + . These data may help design a therapeutic approach that specifically targets the pathogenic immune molecular responsible for autoimmune attacks in IIM.

Subcutaneous immunoglobulin for patients with idiopathic inflammatory myopathies: a real-world single centre experience.

OBJECTIVES: Idiopathic inflammatory myopathies (IIMs) are heterogeneous diseases characterized by skeletal muscle inflammation associated with cutaneous, pulmonary, and/or other visceral organ involvement. Intravenous immunoglobulin (IVIG) has been recommended as an adjunct therapy for IIM patients refractory to conventional therapy. However, IVIG has high resource needs and increased risk of adverse reactions. Subcutaneous immunoglobulin (SCIG) therapy has been used as an alternative to IVIG in primary immunodeficiencies and neuroinflammatory disorders. We assessed the satisfaction, patient preference and effectiveness in IIM patients transitioned from IVIG to SCIG. METHODS: We retrospectively reviewed consecutive 20 patients with IIM who were transitioned from IVIG to SCIG therapy for >12 months. Patient preference between IVIG vs SCIG was surveyed using a questionnaire previously used in studies with neuroinflammatory conditions. In addition, disease flares, changes in immunosuppression, cumulative prednisone doses and global disease activity were evaluated using the Myositis Intention to Treat Index (MITAX) 12-months prior to- and post-SCIG initiation. RESULTS: Most patients (78.9%) preferred SCIG over IVIG and preferred home-based therapies to hospital-based therapies. There was no significant difference in global disease activity (MITAX 3.31 vs 3.02) nor in cumulative steroid doses 12-months prior to- or post-SCIG initiation. Three patients experienced disease flares, 5 escalated in immunosuppression, while 4 patients deescalated in immunosuppressive medications. CONCLUSIONS: SCIG is preferred by most patients over IVIG without a substantial increased disease activity or need for additional corticosteroids. Future cost effectiveness studies may provide an additional rationale for utilizing SCIG over IVIG for maintenance therapy for IIM.

Revisiting idiopathic eosinophilic myositis: towards a clinical-pathological continuum from the muscle to the fascia and skin.

OBJECTIVES: Idiopathic inflammatory myopathies are mainly defined by inflammatory infiltrates within the muscle (lymphocytes and macrophages). Eosinophil muscle infiltration has been described in idiopathic eosinophilic myositis (IEM) and rarely in EF. This study aimed to further delineate the nosological frame of idiopathic eosinophil muscle infiltration through the exhaustive analysis of IEM and EF patients. METHODS: This multicentre retrospective case series included IEM patients diagnosed between 2000 and 2022. IEM inclusion criteria were eosinophilic muscle infiltration with myositis pathological features, after the exclusion of differential diagnoses. An additional group of EF patients diagnosed between 2016 and 2022 was constituted. Inclusion criteria were an EF diagnosis and fascia thickening with inflammatory infiltrate. RESULTS: A total of 20 IEM cases and 10 EF cases were included. The median (interquartile range) age at diagnosis was 65 (49-70) years; there were 18 males. Data analysis delineated four subgroups: focal EM (FEM, n = 3), diffuse EM (DEM, n = 6), eosinophilic myofasciitis (EMF, n = 11) and EF (n = 10). FEM represented a limited and benign form of myositis. DEM cases presented objective muscle impairment with eosinophilic muscle infiltration. EMF patients presented subjective muscle impairment (myalgia, 55%), fasciitis (on histology and/or imaging), eosinophilic muscle infiltration and frequent hypereosinophilia (55%). EF patients presented myalgia (50%), muscle lesions on histology with fascia-restricted inflammatory infiltrates with (60%) or without (40%) eosinophils. CONCLUSIONS: The analysis of IEM and EF patient characteristics delineates four subgroups (FEM, DEM, EMF and EF) in terms of clinical, laboratory, imaging, pathological and outcome specificities, and proposes an adapted diagnostic and care management approach.

Experience with the use of mycophenolate mofetil in juvenile idiopathic inflammatory myopathies.

OBJECTIVE: The objective of this study was to evaluate the efficacy and safety of MMF in juvenile idiopathic inflammatory myopathies (JIIMs). METHODS: Patients diagnosed with JIIM and treated with MMF enrolled in the Juvenile Dermatomyositis Research Group (JDRG) in the UK or followed at the Giannina Gaslini Institute in Genoa, Italy, were included. The following information was collected retrospectively at MMF initiation, at 3, 6 and 12 months after treatment start, and at last follow-up visit: clinical manifestations, laboratory data, physicians' subjective assessment of disease activity, standardized outcome measures of muscle strength/endurance, cutaneous disease activity, physical function, global disease activity, cumulative damage, and ongoing treatment. RESULTS: Of the 29 patients included, 23 had juvenile DM and 6 had overlap myositis. During administration of MMF, improvement in measures of muscle strength, skin disease activity, and overall disease activity was seen, with an increase in the frequency of normal scores for Manual Muscle Test-8 from 50.0% to 83.3%, Childhood Myositis Activity Score from 53.5% to 88.9%, muscle component of DAS from 55.2% to 84.2%, skin component of DAS from 31.0% to 42.1%, visual analogue scale for skin disease activity from 25.0% to 47.4%, and visual analogue scale for overall disease activity from 7.1% to 42.1%. The number of patients with inactive disease increased from 10.3% at baseline to 68.5% at last follow-up. CS dose was significantly reduced, from 0.3 to 0.1 mg/kg/day. No relevant side effects were reported. CONCLUSION: Our experience suggests that MMF is a valuable therapeutic option for the management of JIIM.

Performance of cut-offs adjusted with positive control band intensity in line-blot assays for myositis-specific antibodies.

The diagnostic performance of band intensity (BI) cut-offs, adjusted by a positive control band (PCB) in a line-blot assay (LBA) for myositis-related autoantibodies (MRAs) is investigated. Sera from 153 idiopathic inflammatory myositis (IIM) patients with available immunoprecipitation assay (IPA) data and 79 healthy controls were tested using the EUROLINE panel. Strips were evaluated for BI using the EUROLineScan software, and the coefficient of variation (CV) was calculated. Sensitivity and specificity, area under the curve (AUC), and the Youden's index (YI) were estimated at non-adjusted or PCB-adjusted cut-off values. Kappa statistics were calculated for IPA and LBA. Although inter-assay CV for PCB BI was 3.9%, CV was 12.9% in all samples, and a significant correlation was found between BIs of PCB and seven MRAs (all P < 0.05). At adjusted BI (aBI) > 10, the negative conversion rate of myositis-specific autoantibody (MSA)-positivity at BI > 10 was 11.5% in controls and 1.3% in patients. The specificity, AUC, and YI for MSAs at aBI > 10 or > 20 were higher than those at non-adjusted cut-off values. Additionally, AUC (0.720), YI (0.440), and the prevalence of MRAs with kappa > 0.60 (58.3%) were the highest at aBI > 20. The overall sensitivity and specificity for MSAs were 50.3% and 93.7% at aBI > 20, respectively, and 59.5% and 65.8% with BI > 10, respectively. The diagnostic performance of LBA can be improved using PCB-adjusted BIs. aBI > 20 is the optimal cut-off for IIM diagnosis using the EUROLINE LBA panel.

Chemotherapy induced juvenile dermatomyositis: a novel presentation- a case report.

BACKGROUND: Idiopathic connective tissue disease juvenile dermatomyositis (JDM) is characterised by inflammatory myositis and distinctive skin abnormalities. Only a few cases of Dermatomyositis (DM) owing to chemotherapy used to treat cancer have been reported, despite the fact that the link between DM and cancer in adults is widely known. We describe the case of a female, age 14, who experienced DM as a side effect of chemotherapy following enucleation for retinoblastoma. We also discussed our patient's likely pathophysiology of JDM after treatment. CASE PRESENTATION: A 14-year-old female came to our facility complaining of trouble walking and bluish-black discoloration on her neck, elbows, forehead, and knees that had been present for eight months. The patient had undergone enucleation of the left eye due to retinoblastoma, followed by 40 cycles of radiation therapy and 13 cycles of chemotherapy with Cyclophosphamide, Etoposide, Carboplatin, Vincristine, and Dactinomycin. Her serum LDH and CPK levels were high, and she tested positive for ANA. The muscle biopsy was consistent with the changes of DM. When electromyography was performed, it revealed tiny, fibrillating, polyphasic motor unit potentials and sharp, positive waves that were suggestive with DM. A diagnosis of JDM was made after taking into account the symptoms, biochemical data, muscle biopsy, and electromyography results. The patient's symptoms started to get better once methotrexate and oral corticosteroids were started. CONCLUSION: This case report emphasises the value of ongoing observation after cancer chemotherapy because specific cutaneous and muscle symptoms may lead paediatricians to consider the possibility of chemotherapy-induced JDM, which is uncommon in young patients.

Role of MRI in idiopathic inflammatory myopathies: a review article.

Idiopathic inflammatory myopathies are a rare heterogeneous group of chronic, autoimmune conditions characterized by the slow, progressive weakness of the skeletal muscles and inflammatory infiltrates in the muscle tissue. The predominant role of magnetic resonance imaging (MRI) in myositis imaging is to assess disease activity and to identify the target site for biopsy. Its role in phenotyping the disease is less explored. The aim of the present review was to examine the role of MRI in differentiating between the common inflammatory myopathies, i.e. dermatomyositis, polymyositis, and sporadic inclusion body myositis, and to describe the specific spectrum of MRI findings in various inflammatory myopathies.

Clinicopathological Characteristics of Inflammatory Myositis Induced by COVID-19 Vaccine (Pfizer-BioNTech BNT162b2): A Case Report.

As more individuals were coronavirus disease 2019 (COVID-19) vaccinated, unexpected side effects appeared. Herein, we present the case of a 30-year-old man with myopathy in both extremities after the second dose of the Pfizer-BioNTech (BNT162b2) COVID-19 vaccine. Symptoms, swelling and pain, started from the proximal upper and lower extremities and extended to the distal parts. Although he underwent massive hydration, the muscle enzyme level continuously increased. He complained of dysphagia and dysarthria. Microscopically, muscle biopsy showed multifocal or scattered macrophage infiltration and degenerated myofibers. In contrast to general myopathy including inflammatory myositis and rhabdomyolysis, vaccine-induced inflammatory myositis shows a prolonged increase in muscle enzyme levels and multifocal macrophage infiltration with necrosis of the muscle fibers. Symptoms improved with glucocorticoid and immunosuppressive treatment. If vaccinated individuals experience severe and continuous muscle pain and swelling, clinicians should consider vaccine-induced inflammatory myositis, measure the muscle enzyme levels, and perform muscle biopsy for a definite diagnosis.

Nailfold capillaroscopy changes with disease activity in patients with inflammatory myositis including overlap myositis, pure dermatomyositis, and pure polymyositis.

Objectives: Nailfold capillaroscopy (NFC) is useful in the evaluation of connective tissue diseases. There are few capillaroscopy examinations in patients with idiopathic inflammatory myopathies (IIMs) using the 2017 European League Against Rheumatism/American College of Rheumatology (EULAR/ACR) classification. We evaluated the clinical, laboratory, and NFC in patients with IIMs using 2 classifications. Material and methods: In this cross-sectional study, 150 patients with IIMs were selected based on the EULAR/ACR classification and the Troyanov and Senécal classification. Nailfold capillaroscopy, laboratory tests, clinical manifestations, and disease activity were evaluated. Results: The subgroups were as follows: 81 patient with dermatomyositis (DM), 25 with amyopathic dermatomyositis (ADM), 25 with juvenile dermatomyositis (JDM), 19 with polymyositis (PM),53 with pure DM, 11 with pure PM, and 51 with overlap myositis (OM). Eight (42%) patients with PM and 28 (34.5%) patients with DM were categorized as OM. The scleroderma pattern was the dominant capillaroscopy pattern in the DM (72.8%), JDM (72%), ADM (76%), pure DM (75.4%), and OM (78.4%) subgroups, respectively. In the DM, ADM, JDM, and OM subgroups, scleroderma pattern had an association with high skin Visual Analogue Scale (VAS) score (p < 0.05). In OM patients, the association between scleroderma pattern and high global VAS was also detected (p < 0.05). Conclusions: The scleroderma pattern was the dominant capillaroscopy pattern in all groups except for PM and pure PM. Some of patients with PM could be categorized as OM. In the DM and pure DM subgroups, there was a significant association between global and skin activity and higher NFC score. Adding the NFC to the classification of IIM is probably helpful in more detailed classifications.

External validation of the EULAR/ACR idiopathic inflammatory myopathies classification criteria with a Japanese paediatric cohort.

OBJECTIVES: To assess the performance of the EULAR/ACR idiopathic inflammatory myopathies (IIMs) classification criteria to classify juvenile IIMs (JIIMs) in an Asian paediatric population. METHODS: Sixty-eight JIIM patients and 49 non-JIIM patients diagnosed at seven major paediatric rheumatology centres in Japan between 2008 and 2015 were enrolled. Retrospective data were collected, and each patient's data form was submitted. The expert group reviewed the forms and re-examined the diagnoses. The EULAR/ACR criteria were then applied and the probability of having JIIM was determined for each case. The sensitivity and specificity of the EULAR/ACR criteria were compared with those of other existing criteria. RESULTS: The sensitivity/specificity of the EULAR/ACR classification criteria were 92.1/100% with muscle biopsy data (n = 38); 86.7/100% without muscle biopsy data (n = 30) and 89.7/100% in our total cohort (n = 68). The sensitivity of Bohan and Peter's criteria and Tanimoto's criteria were 80.9 and 64.7% in our total cohort, respectively. Among 68 physician-diagnosed JIIM patients, seven cases (three JDM and four overlap myositis) were not classified as JIIM because the probability did not reach the cut-off point (55%). The three JDM patients all presented with only one of the three skin manifestations that are listed in the criteria: Gottron's sign. CONCLUSION: Our validation study with Japanese JIIM cases indicates that the EULAR/ACR classification criteria for IIM generally perform better than existing diagnostic criteria for myositis.

Lung ultrasound B-lines and serum KL-6 correlate with the severity of idiopathic inflammatory myositis-associated interstitial lung disease.

OBJECTIVE: Idiopathic inflammatory myositis-associated interstitial lung disease (IIM-ILD) significantly increases morbidity and mortality. Lung ultrasound B-lines and Krebs von den Lungen-6 (KL-6) are identified as new sonographic and serum markers of ILD, respectively. The aim of our work was to assess the role of B-lines and KL-6 as markers of the severity of IIM-ILD. For this purpose, the correlation among B-lines score, serum KL-6 levels, high-resolution CT (HRCT) score, and pulmonary function tests were investigated in IIM-ILD patients. METHODS: Thirty-eight patients with IIM-ILD underwent chest HRCT scans, lung ultrasound and pulmonary function tests (independently performed within 1 week) examination. To assess severity and extent of ILD at HRCT, the Warrick score was used. The B-lines score denoting the extension of ILD was calculated by summing the number of B-lines on a total of 50 scanning sites. Serum KL-6 levels (U/ml) was measured by chemiluminescent enzyme immunoassay. RESULTS: A significant correlation was found between the B-lines score and serum KL-6 levels (r = 0.43, P < 0.01), and between the Warrick score and serum KL-6 levels (r = 0.45, P < 0.01). A positive correlation between B-lines score and the Warrick score (r = 0.87, P < 0.0001) was also confirmed. Both B-lines score and KL-6 levels inversely correlated to diffusion capacity for carbon monoxide (r = -0.77, P < 0.0001 and r = -0.42, P < 0.05, respectively) and total lung capacity (r = -0.73, P < 0.0001 and r = -0.36, P < 0.05, respectively). Moreover, B-lines correlated inversely with forced vital capacity (r = -0.73, P < 0.0001), forced expiratory volume in 1 s (r = -0.69, P < 0.0001). CONCLUSION: B-lines score and serum KL-6 levels correlate with HRCT findings and pulmonary function tests, supporting their use as measures of IIM-ILD severity.

Inflammatory myositis in systemic lupus erythematosus.

BACKGROUND: The coexistence of inflammatory myositis in systemic lupus erythematosus (SLE) has not been extensively studied. In this study, we describe the incidence, distinct types of inflammatory myositis, and risk factors for this finding in a cohort of pediatric and adult SLE patients. METHODS: We identified SLE patients with coexisting myositis followed between 2010 and 2019 at two pediatric hospitals and one adult hospital. Demographic, clinical, laboratory, and pathological features of myositis were collected, and descriptive statistics were applied. RESULTS: A total of 1718 individuals were identified as having SLE (451 pediatric and 1267 adult patients). Of these, 108 were also diagnosed with inflammatory myositis (6.3%). People of black race had a significantly higher prevalence of inflammatory myositis, as did those with childhood-onset SLE compared to adult-onset disease. In the majority of patients (68%), SLE and inflammatory myositis presented concurrently. Overlapping features of systemic sclerosis occurred in 48%, while dermatomyositis-specific rashes were present in a third. Arthralgias and inflammatory arthritis were seen in >90%. Thrombotic events and significant pregnancy-related morbidity were present in more than a third of patients. Lymphopenia, hypocomplementemia, and a positive RNP were the most common laboratory features noted. Myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) were present in >40% of patients. A review of 28 muscle biopsy reports revealed a wide array of pathological features, including nonspecific changes, dermatomyositis, polymyositis, and necrotizing auto-immune myopathy. CONCLUSION: In our SLE patient population, 6.3% presented with concurrent inflammatory myositis. Dermatomyositis-specific rashes, clinical features of systemic sclerosis, arthralgias and arthritis, and cytopenias were common coexisting clinical manifestations. A high frequency of RNP, MSA, and MAA were found. People of black race and with childhood-onset disease had a higher prevalence of myositis. Our findings suggest that SLE patients of black race, with childhood-onset SLE, and who possess MSA or MAA should be routinely screened for myositis.

Pneumocystis jirovecii Pneumonia and Other Infections in Idiopathic Inflammatory Myositis.

PURPOSE OF REVIEW: The management of patients with idiopathic inflammatory myositis (IIM) can be complex and challenging due to the myriad of complications they can experience. The continued use of corticosteroids, in addition to the rise of combination immunosuppressive therapy, has contributed to the ongoing concern for infection. Perhaps the most feared infection in IIM patients is Pneumocystis jirovecii pneumonia (PJP) given its infrequent occurrence yet high mortality. The field has been, and continues to be, without evidence-based guidelines to help clinicians determine which patients with IIM to prescribe prophylaxis. Herein, we review this literature to provide the clinician with an up-to-date view of infections in IIM. RECENT FINDINGS: In the past 5 years, a number of studies have been reported highlighting various infectious complications, which help us better understand their frequency and associated risk factors. In addition, data has been published on the potential harms of PJP prophylaxis, to better inform the risk/benefit of our decision-making. Infection remains a major contributor to morbidity and mortality in IIM. A better understanding of which patient subgroups are at risk for particular infections will inform optimal management strategies.

Linear Morphea With Inflammatory Myositis.

Morphea is an autoimmune disorder characterized by sclerosis and inflammation of the skin and soft tissues. Early diagnosis and treatment are essential to minimize morbidity such as joint contracture. In this report, we present the case of a 19-year-old man with linear morphea with inflammatory myositis who presented to our clinic 1 year after symptom onset with severe elbow flexion contracture. Through reviewing this rare disorder, it is hoped that early diagnosis will lead to better outcomes in the future.

Increased risk of coronary heart disease among patients with idiopathic inflammatory myositis: a nationwide population study in Taiwan.

OBJECTIVE: To evaluate the risk of incident coronary heart disease (CHD) among patients with DM and PM in a general population context. METHODS: We conducted a retrospective cohort study using the Taiwan National Health Insurance Research Database containing records covering the years from 2000 to 2010. DM and PM were confined for the purposes of this study to those aged ⩾18 years who were eligible for the Taiwan catastrophic illness certificate. The diagnoses, CHD outcomes and cardiovascular risk factors were identified from electronic claims data. We conducted two cohort analyses: CHD and DM, and CHD and PM, excluding for each analysis individuals with CHD already identified at baseline. Data for the comparison group was obtained from the Longitudinal Health Insurance database, comprising 1 million persons randomly sampled from the total beneficiaries during 2000. We estimated hazard ratios comparing myositis with comparison cohorts, adjusting for potential cardiovascular risk factors. RESULTS: A total of 1145 patients with idiopathic myositis were identified, along with 732 723 control patients aged ⩾18 years. The incidence rates of CHD were 15.1 in DM and 30.1 in PM per 1000 person-years, vs 8.4 and 10.5 per 1000 person-years in the comparison cohort. The adjusted hazard ratios for CHD in patients with idiopathic myositis were 2.21 (95% CI 1.64, 2.99) for DM and 3.73 (95% CI 2.83, 4.90) for PM. CONCLUSION: Results of this general population-based cohort study suggest that DM and PM are associated with an increased risk of CHD.

Development and validation of a composite disease activity score for measurement of muscle and skin involvement in juvenile dermatomyositis.

OBJECTIVE: To develop a composite DAS for JDM and provide preliminary evidence of its validity. METHODS: The Juvenile DermatoMyositis Activity Index (JDMAI) is composed of four items: physician's global assessment of overall disease activity; parent's/child's global assessment of child's wellbeing; measurement of muscle strength; and assessment of skin disease activity. The score of the JDMAI is the arithmetic sum of the scores of each individual component. Six versions of the JDMAI were tested, which differed in the tools used to assess the third and fourth items. Validation procedures were conducted using three large multinational patient samples including a total of 627 patients. RESULTS: The JDMAI was found to possess face and content validity, good construct validity, satisfactory internal consistency (Cronbach's alpha = 0.58-0.89), fair responsiveness to clinically important change (standardized response mean = 0.82-3.12 among patients improved) and strong capacity to discriminate patients judged as being in the state of inactive disease or low, moderate or high disease activity by the physician (P < 0.001) or whose parents were satisfied or not satisfied with the course of their child's illness (P < 0.001). Overall, the six versions of the JDMAI showed similar metrological performances in validation analyses. CONCLUSION: The JDMAI was found to possess good measurement properties in a large population of patients with a wide range of disease activity, and is, therefore, suitable for use in both clinical and research settings. The final version of the JDMAI will be selected after its prospective validation.

Screening for Myositis Antibodies in Idiopathic Interstitial Lung Disease.

PURPOSE: International guidelines recommend screening for connective tissue disease (CTD) with autoantibodies when evaluating patients with idiopathic interstitial lung disease (ILD). Idiopathic inflammatory myositis comprises of a subgroup of CTD diagnosed with myositis antibodies (MA), often presenting with ILD. Our aim was to evaluate the utility of MA screening in patients with idiopathic ILD. METHODS: A retrospective analysis was conducted on patients referred with idiopathic ILD to a tertiary centre ILD clinic who were screened for MA. Patients with known or suspected CTD were excluded. Descriptive statistics, univariate analysis and multivariable logistic regression were used to detect associations between MA and patient characteristics. RESULTS: Of 360 patients, 165 met inclusion criteria and 44 (26.7%) were identified to have MA. Fourteen patients (8.5%) had a change in diagnosis as a result of MA screening. Multivariable logistic regression identified the presence of MA to be associated with current smoking [OR 6.87 (1.65-28.64), p = 0.008] and a diffusing capacity of < 70% predicted [OR 2.55 (1.09-5.97), p = 0.03]. In patients with a change in diagnosis due to MA screening, 3 (1.8%) underwent a surgical lung biopsy and 2 (1.2%) were previously treated with antifibrotic therapy. CONCLUSIONS: Screening for MA in patients with idiopathic ILD can contribute to a change in patient diagnosis, and may prevent invasive testing and unproven use of antifibrotic therapy. These results support the addition of MA to CTD screening panels during the initial evaluation of idiopathic ILD.