Myositis and Its Mimics: Guideline Updates, MRI Characteristics, and New Horizons.

Myositis is defined as inflammation within skeletal muscle and is a subcategory of myopathy, which is more broadly defined as any disorder affecting skeletal muscle. Myositis may be encountered as a component of autoimmune and connective tissue disease, where it is described as idiopathic inflammatory myopathy. Myositis can also be caused by infections, as well as toxins and drugs, including newer classes of medications. MRI plays an important role in the diagnosis and evaluation of patients with suspected myositis, but many entities may have imaging features similar to myositis and can be considered myositis mimics. These include muscular dystrophies, denervation, deep venous thrombosis, diabetic myonecrosis, muscle injury, heterotopic ossification, and even neoplasms. In patients with suspected myositis, definitive diagnosis may require integrated analysis of imaging findings with clinical, laboratory, and pathology data. The objectives of this article are to review the fundamental features of myositis, including recent updates in terminology and consensus guidelines for idiopathic inflammatory myopathies, the most important MRI differential diagnostic considerations for myositis (i.e., myositis mimics), and new horizons, including the potential importance of artificial intelligence and multimodal integrated diagnostics in the evaluation of patients with muscle disorders.

International Guideline for Idiopathic Inflammatory Myopathy-Associated Cancer Screening: an International Myositis Assessment and Clinical Studies Group (IMACS) initiative.

Adult-onset idiopathic inflammatory myopathy (IIM) is associated with an increased cancer risk within the 3 years preceding and following IIM onset. Evidence- and consensus-based recommendations for IIM-associated cancer screening can potentially improve outcomes. This International Guideline for IIM-Associated Cancer Screening provides recommendations addressing IIM-associated cancer risk stratification, cancer screening modalities and screening frequency. The international Expert Group formed a total of 18 recommendations via a modified Delphi approach using a series of online surveys. First, the recommendations enable an individual patient's IIM-associated cancer risk to be stratified into standard, moderate or high risk according to the IIM subtype, autoantibody status and clinical features. Second, the recommendations outline a 'basic' screening panel (including chest radiography and preliminary laboratory tests) and an 'enhanced' screening panel (including CT and tumour markers). Third, the recommendations advise on the timing and frequency of screening via basic and enhanced panels, according to risk status. The recommendations also advise consideration of upper or lower gastrointestinal endoscopy, nasoendoscopy and 18F-FDG PET-CT scanning in specific patient populations. These recommendations are aimed at facilitating earlier IIM-associated cancer detection, especially in those who are at a high risk, thus potentially improving outcomes, including survival.

The Type I Interferon Signature Reflects Multiple Phenotypic and Activity Measures in Dermatomyositis.

OBJECTIVE: The type 1 interferon (IFN) pathway is up-regulated in dermatomyositis (DM). We sought to define how organ-specific disease activity as well as autoantibodies and other clinical factors are independently associated with systemic type I IFN activity in adult patients with DM. METHODS: RNA sequencing was performed on 355 whole blood samples collected from 202 well-phenotyped DM patients followed up during the course of their clinical care. A previously defined 13-gene type I IFN score was modeled as a function of demographic, serologic, and clinical variables using both cross-sectional and longitudinal data. RESULTS: The pattern of type I IFN-driven transcriptional response was stereotyped across samples with a sequential modular activation pattern strikingly similar to systemic lupus erythematosus. The median type I IFN score was higher or lower in patients with anti-melanoma differentiation-associated protein 5 (anti-MDA-5) or anti-Mi-2 antibodies, respectively, compared to patients without these antibodies. Absolute type I IFN score was independently associated with muscle and skin disease activity, interstitial lung disease, and anti-MDA-5 antibodies. Changes in the type I IFN score over time were significantly associated with changes in skin or muscle disease activity. Stratified analysis accounting for heterogeneity in organ involvement and antibody class revealed high correlation between changes in the type I IFN score and skin disease activity (Spearman's ρ = 0.84-0.95). CONCLUSION: The type I IFN score is independently associated with skin and muscle disease activity as well as certain clinical and serologic features in DM. Accounting for the effect of muscle disease and anti-MDA-5 status revealed that the type I IFN score is strongly correlated with skin disease activity, providing support for type I IFN blockade as a therapeutic strategy for DM.

Clinical Associations of Degos-Like Lesions in Patients With Systemic Sclerosis.

Importance: Degos-like lesions are cutaneous manifestations of a small-vessel vasculopathy that appear as atrophic, porcelain-white papules with red, telangiectatic borders. No study has adequately examined Degos-like lesions in patients with systemic sclerosis (SSc). Objective: To characterize the serologic, cutaneous, and internal organ manifestations associated with Degos-like lesions in a large cohort of patients with SSc. Design, Settings, and Participants: This retrospective cohort study involved adult patients with SSc who were seen at Stanford Rheumatologic Dermatology Clinic between January 1, 1998, and December 31, 2018. Participants fulfilled the 2013 classification criteria for SSc. Data analysis was conducted from February 1 to June 1, 2019. Main Outcomes and Measures: Data on demographic characteristics; autoantibody status; clinical characteristics, including cutaneous and systemic manifestations of SSc; and presence of Degos-like lesions were collected. Results: The cohort comprised 506 patients with SSc (447 females [88.3%]; mean [SD] age at first non-Raynaud disease symptoms, 46.1 [15.2] years). Twenty-seven patients (5.3%) had Degos-like lesions, of whom 24 (89.0%) had lesions affecting the fingers. Patients with Degos-like lesions were more likely to have diffuse cutaneous SSc compared with patients without lesions (15 [55.6%] vs 181 [37.8%]; P = .04). Degos-like lesions were also associated with acro-osteolysis (10 [37.0%] vs 62 [12.9%]; P < .01), digital ulcers (15 [55.6%] vs 173 [36.1%]; P = .04), and calcinosis (15 [55.6%] vs 115 [24.0%]; P < .01). While Degos-like lesions were not associated with internal organ manifestations, such as scleroderma renal crisis, interstitial lung disease, or pulmonary arterial hypertension, there was P < .10 for the association with gastric antral vascular ectasia. Conclusions and Relevance: Results of this study suggest an association of Degos-like lesions with diffuse cutaneous SSc and other cutaneous manifestations of vasculopathy, including acro-osteolysis, calcinosis, and digital ulcers. A prospective longitudinal study is warranted to examine the onset of Degos-like lesions and to elucidate whether these lesions play a role in SSc.

Association of Anti-CCAR1 Autoantibodies With Decreased Cancer Risk Relative to the General Population in Patients With Anti-Transcriptional Intermediary Factor 1γ-Positive Dermatomyositis.

OBJECTIVE: To describe the disease specificity, clinical phenotype, and risk of cancer in dermatomyositis (DM) patients with autoantibodies against cell division cycle and apoptosis regulator protein 1 (anti-CCAR1). METHODS: The frequency of anti-CCAR1 autoantibodies was measured by enzyme-linked immunosorbent assay in the serum of DM patients from 2 independent cohorts (Johns Hopkins and Stanford), with patients with several other rheumatic diseases and healthy controls used as comparators. Clinical features and the risk of cancer incidence relative to that in the general population were determined in anti-CCAR1-positive DM patients. RESULTS: Anti-CCAR1 antibodies were significantly associated with anti-transcriptional intermediary factor 1γ (anti-TIF1γ) antibodies present in the serum of patients with DM: 80 (32%) of 252 anti-TIF1γ-positive DM patients versus 14 (8%) of 186 anti-TIF1γ-negative DM patients were positive for anti-CCAR1 antibodies (P < 0.001). Anti-CCAR1 antibodies were not detected in any of the 32 serum samples from healthy controls, and were present at very low frequencies in the sera of patients with other rheumatic diseases: 1 (2.3%) of 44 patients with anti-hydroxymethylglutaryl-coenzyme A reductase-positive necrotizing myopathy, 1 (2.3%) of 44 patients with inclusion body myositis, and 3 (6.5%) of 46 patients with systemic lupus erythematosus were positive for anti-CCAR1 antibodies. Upon examining data on occurrence of cancer from the onset of DM onward, the observed number of cancers diagnosed in anti-TIF-1γ-positive DM patients was significantly greater than expected in both cohorts, with a standardized incidence ratio (SIR) of 3.49 (95% confidence interval [95% CI] 2.39-4.92) in the Johns Hopkins cohort and a SIR of 4.54 (95% CI 3.04-6.52) in the Stanford cohort (each P < 0.001). DM patients who were both anti-TIF1γ positive and anti-CCAR1 positive had lower SIRs for cancer, with a SIR of 1.78 (95% CI 0.77-3.51) (P = 0.172) in the Johns Hopkins cohort and a SIR of 1.61 (95% CI 0.44-4.13) (P = 0.48) in the Stanford cohort. CONCLUSION: Anti-CCAR1 autoantibodies are specific for anti-TIF1γ-positive DM. Their presence in anti-TIF1γ-positive patients attenuates the risk of cancer to a level comparable to that seen in the general population.

Cessation of Immunomodulatory Medication Use in Dermatomyositis: A Single-Center Cohort Study.

OBJECTIVE: To determine the frequency with which adults with dermatomyositis (DM) are able to discontinue systemic immunomodulatory therapy and factors associated with medication cessation. METHODS: We studied a cohort of adult DM patients seen in a rheumatology/dermatology clinic between 2013 and 2020. All patients had exposure to at least 1 systemic immunomodulatory medication for a minimum of 3 months and were followed until medications were discontinued for at least 12 months. Survival analysis was performed using Kaplan-Meier curves with log-rank analyses, and multivariate analysis was done using Cox proportional hazards models. RESULTS: A total of 246 DM patients were followed up for a median time of ∼7 years (47-134 months). Forty-seven patients (19%) discontinued all immunomodulatory medications with a median follow-up of ∼3 years (interquartile range 22-108 months) following DM onset. Log-rank analysis demonstrated that those with anti-MDA5 autoantibodies discontinued medications faster compared with those without autoantibodies (P = 0.03). Multivariate modeling showed that clinically amyopathic patients were 2.7-fold (95% confidence interval [95% CI] 1.34-5.59) more likely to discontinue medications than those with muscle disease. Those with anti-MDA5, anti-NXP2, and anti-SAE1 antibodies had increased likelihood of medication cessation with hazard ratios of 9.83 (95% CI 2.00-48.2), 8.92 (95% CI 1.69-47.0), and 10.8 (95% CI 2.06-56.6), respectively, when compared with the autoantibody-negative group. CONCLUSION: Approximately 20% of adult DM patients discontinued immunomodulatory medications over a median 7-year follow-up. Those with clinically amyopathic disease, anti-MDA5, anti-NXP2, and anti-SAE1 antibodies have a higher likelihood of medication cessation.

Autoantibodies and Cancer Association: the Case of Systemic Sclerosis and Dermatomyositis.

Several rheumatic diseases have a perplexing association with cancer. Unraveling this mysterious connection is likely to provide deeper understanding regarding mechanisms governing the onset of both autoimmunity and cancer immunity, in addition to providing clinicians much needed guidance around whom and when to screen for occult malignancy. Systemic sclerosis (scleroderma) and dermatomyositis are two diseases in which the association with internal malignancy is well-described and can be considered as models from which to gain important insights that likely have broader applicability. The past 15 years have witnessed a striking acceleration in understanding how these two diseases are related to cancer emergence-an important crack in this inscrutable armor has been the discovery and characterization of disease-specific autoantigens that are closely tied with risk of cancer emergence. The best-described examples of this are antibodies against anti-RNA polymerase III (anti-POL3) and transcription intermediary factor 1-gamma (anti-TIF1γ). Patients with systemic sclerosis and cancer that are diagnosed within a short time interval of each other frequently have anti-POL3 antibodies. Antibodies against the minor spliceosome protein RNA-Binding Region Containing 3 (RNPC3) are also associated with increased cancer incidence in systemic sclerosis. Similarly, in the dermatomyositis spectrum, the majority of anti-TIF1γ-associated cancers are detected around the time of DM onset (most often within 1 year). Antibodies against Nuclear Matrix Protein 2 are also potentially associated with increased cancer emergence in dermatomyositis. The systemic sclerosis/anti-POL3 connection with close cancer onset led to the first experiments directly supporting the concept that rheumatic disease may in fact be a manifestation of cancer. It is now clear that studying these diseases through the lens of autoantibodies can reveal relationships and insights that would otherwise remain obscured. Extending these studies, new findings show that antibodies against RNA polymerase I large subunit are associated with protection against short interval cancers in anti-POL3-positive systemic sclerosis patients. These insights highlight the fact that autoantigen discovery related to cancer emergence remains an important priority; such new tools will enable the testing of specific hypotheses regarding mechanisms governing disease emergence and development of effective anti-tumor responses. Autoantibody phenotype will likely play an important role in the development of cancer screening guidelines that are critically needed by clinicians taking care of these patients. In this review, we will summarize the current state of knowledge regarding the different ways in which autoantibodies are connected with systemic sclerosis/dermatomyositis and malignancy and highlight potential paths forward.

Defining anti-synthetase syndrome: a systematic literature review.

OBJECTIVES: Anti-synthetase syndrome (ASSD) is a heterogeneous autoimmune disease characterised by multi-system involvement with a wide variety of manifestations. Validated classification criteria are necessary to improve recognition and prevent misclassification, especially given the lack of reliable and standardised autoantibody testing. We systematically reviewed the literature to analyse proposed ASSD criteria, characteristics, and diagnostic performance. METHODS: We searched PubMed and Embase databases (01/01/1984 to 06/11/2018) and the ACR and EULAR meeting abstracts (2017-2018). Sensitivities, specificities, positive, negative likelihood ratios and risk of bias were calculated for ASSD criteria and key variables reported in the literature. We performed meta-analysis when appropriate. RESULTS: We retrieved 4,358 studies. We found 85 proposed ASSD criteria from a total of 82 studies. All but one study included anti-synthetase autoantibody (ARS) positivity in the ASSD criteria. Most studies required only one ASSD feature plus anti-ARS to define ASSD (n=64, 78%), whereas 16 studies required more than one ASSD variable plus anti-ARS. The only criteria not including anti-ARS positivity required 5 ASSD clinical features. We found limited data and wide variability in the diagnostic performance of each variable and definition proposed in the literature. Given these limitations we only meta-analysed the performance of individual muscle biopsy and clinical variables in diagnosing ASSD, which performed poorly. CONCLUSIONS: The current ASSD criteria include a variety of serological, clinical, and histological features with wide variability amongst proposed definitions and the performance of these definitions has not been tested. This systematic literature review suggests the need for additional data and consensus-driven classification criteria for ASSD.

Change in calcinosis over 1 year using the scleroderma clinical trials consortium radiologic scoring system for calcinosis of the hands in patients with systemic sclerosis.

INTRODUCTION: Calcinosis cutis is a debilitating complication of systemic sclerosis (SSc). We previously developed a radiographic scoring system to assess severity of calcinosis affecting the hands in patients with SSc. We sought to further validate our radiographic scoring system to assess for change over 1 year and to identify factors associated with improvement or progression. MATERIALS AND METHODS: Baseline and 1-year antero-posterior hand radiographs were obtained in 39 SSc patients with calcinosis prospectively enrolled at 6 centers within the US, Canada, Mexico and Australia. Two readers (one radiologist and one rheumatologist) scored all radiographs using the calcinosis scoring system and a 5-point Likert scale (1 = A lot better, 2 = A little better, 3=No change, 4 = A little worse, 5 = A lot worse) on follow-up. By maximizing the Kappa coefficient of agreement between grouped Likert scale (better/no change/worse) and the percentage of change of calcinosis in the radiographic scoring system, we defined progressive calcinosis as >25% increase in score from baseline at 1-year, stable calcinosis as change in score between -25% to 25%, and improvement of calcinosis as decrease in score by >25%. Nineteen SSc patients from an independent cohort were used for validation. RESULTS: Inter-rater reliability of the calcinosis scoring system was high with intra-class correlation coefficient of 0.93 (0.89-0.95). The median percentage of change from baseline to 1 year was 12.8% (range -89.3 to 290.2%). Sixteen patients (41%) experienced progression of calcinosis over 1 year; 18 (46%) remained stable; and 5 (13%) had improvement. Patients with progressive calcinosis had lower T-score on bone densitometry (-3.3 vs -1.7, p = 0.044) and higher prevalence of loss of digital pulp on physical exam (56% vs 22%, p = 0.027), with a trend towards lower baseline modified Rodnan skin score (mRSS) (3.8 vs. 5.9, p = 0.057), than patients who did not progress. Patients who experienced improvement in calcinosis had lower prevalence of digital pitting scars (20% vs 71%, p = 0.047) than patients whose calcinosis did not improve. In multivariable analysis, loss of digital pulp remained a predictor of calcinosis progression (OR 5.8, p = 0.023, CI 1.27 - 26.36). In the validation cohort, 2 (11%) patients improved, 10 (53%) remained stable, and 7 (37%) progressed. CONCLUSIONS: We confirmed the excellent inter-rater reliability of our radiographic calcinosis scoring system and demonstrated its usefulness to detect change over time. Approximately 40% of patients experienced progression of calcinosis over 1 year. Loss of digital pulp was predictive of progressive calcinosis providing further evidence that digital ischemia contributes to the progression of calcinosis.

Immune responses to CCAR1 and other dermatomyositis autoantigens are associated with attenuated cancer emergence.

BACKGROUNDThe temporal clustering of a cancer diagnosis with dermatomyositis (DM) onset is strikingly associated with autoantibodies against transcriptional intermediary factor 1-γ (TIF1-γ). Nevertheless, many patients with anti-TIF1-γ antibodies never develop cancer. We investigated whether additional autoantibodies are found in anti-TIF1-γ-positive patients without cancer.METHODSUsing a proteomic approach, we defined 10 previously undescribed autoantibody specificities in 5 index anti-TIF1-γ-positive DM patients without cancer. These were subsequently examined in discovery (n = 110) and validation (n = 142) cohorts of DM patients with anti-TIF1-γ autoantibodies.RESULTSWe identified 10 potentially novel autoantibodies in anti-TIF1-γ-positive DM patients, 6 with frequencies ranging from 3% to 32% in 2 independent DM cohorts. Autoantibodies recognizing cell division cycle and apoptosis regulator protein 1 (CCAR1) were the most frequent, and were significantly negatively associated with contemporaneous cancer (discovery cohort OR 0.27 [95% CI 0.7-1.00], P = 0.050; validation cohort OR 0.13 [95% CI 0.03-0.59], P = 0.008). When cancer did emerge, it occurred significantly later in anti-CCAR1-positive compared with anti-CCAR1-negative patients (median time from DM onset 4.3 vs. 0.85 years, respectively; P = 0.006). Cancers that emerged were more likely to be localized (89% of anti-CCAR1-positive cancers presenting at stage 0 or 1 compared with 42% of patients without anti-CCAR1 antibodies, P = 0.02). As the number of additional autoantibody specificities increased in anti-TIF1-γ-positive DM patients, the frequency of cancer decreased (P < 0.001).CONCLUSIONAs the diversity of immune responses in anti-TIF1-γ DM patients increases, the likelihood of cancer emerging decreases. Our findings have important relevance for cancer risk stratification in DM patients and for understanding natural immune regulation of cancer in humans.TRIAL REGISTRATIONNot applicable.FUNDING SOURCESThe NIH, the Donald B. and Dorothy L. Stabler Foundation, and the Huayi and Siuling Zhang Discovery Fund.

A pilot study to evaluate the safety and efficacy of treprostinil in the treatment of calcinosis in systemic sclerosis.

OBJECTIVES: We evaluated the safety and efficacy of oral treprostinil in preventing progression of SSc-associated calcinosis. METHODS: This prospective open-label study enrolled 12 SSc patients meeting 2013 ACR/EULAR classification criteria with confirmed clinical and radiographic evidence of one or more calcinosis deposit in the hands. Patients received oral treprostinil for 1 year. Primary endpoints were safety/tolerability and percentage of patients without radiographic progression of calcinosis at 1 year (<25% increase in Scleroderma Clinical Trials Consortium radiographic score). Secondary endpoints included 1-year changes in Scleroderma HAQ (SHAQ), Cochin Hand Functional Scale, Medical Outcomes Survey Short Form 36 (SF-36), Raynaud Condition Score and patient/physician assessment of calcinosis severity. RESULTS: Twelve female patients were enrolled, half with diffuse cutaneous disease; median age was 55 years (range 35-68 years). Five patients completed the study. Seven patients withdrew due to intolerable adverse effects (n = 3), intercurrent unrelated illness (n = 2, cirrhosis, cancer), progressive SSc (n = 1) and personal reasons (n = 1). Most patients developed headaches and gastrointestinal adverse effects. Four of 11 (36%) patients with 1-year follow-up hand radiographs experienced progression of calcinosis. Of five who completed treatment, calcinosis was stable in four (80%) with progression in one. Based on SF-36 Physical and Mental Component and Domain scores, transition question and SF-6D utility score, all patients who finished the trial reported overall improvement or no change compared with baseline. CONCLUSION: Oral treprostinil was poorly tolerated in SSc patients with calcinosis. Of five patients who completed treatment, most (80%) had documented stability of calcinosis on hand radiographs at 1 year. CLINICALTRIALS.GOV IDENTIFIER: NCT02663895.

Peripheral blood leucocyte telomere length is associated with progression of interstitial lung disease in systemic sclerosis.

BACKGROUND: Peripheral blood leucocyte telomere length (PBL-TL) is associated with outcomes in patients with idiopathic pulmonary fibrosis. Whether PBL-TL is associated with progression of systemic sclerosis-associated interstitial lung disease (SSc-ILD) is unknown. METHODS: A retrospective observational cohort study was performed using prospectively collected data from 213 patients with SSc followed at the University of California San Francisco (UCSF) Scleroderma Center. PBL-TL was measured by quantitative PCR of DNA isolated from peripheral blood. Associations between PBL-TL and pulmonary function test trends in patients with SSc-ILD were assessed by longitudinal analysis using Generalised Linear Mixed Models. Findings were validated in a cohort of 61 patients with SSc-ILD enrolled in the Stanford University Scleroderma Center database. RESULTS: Patients with UCSF SSc with ILD were found to have shorter PBL-TL compared with those without ILD (6554±671 base pairs (bp) vs 6782±698 bp, p=0.01). Shorter PBL-TL was associated with the presence of ILD (adjusted OR 2.1 per 1000 bp TL decrease, 95% CI [1.25 to 3.70], p=0.006). PBL-TL was shorter in patients with SSc-ILD lacking SSc-specific autoantibodies compared with seropositive subjects (6237±647 bp vs 6651±653 bp, p=0.004). Shorter PBL-TL was associated with increased risk for lung function deterioration with an average of 67 mL greater loss in per year for every 1000 bp decrease in PBL-TL in the combined SSc-ILD cohorts (longitudinal analysis, adjusted model: 95% CI -104 mL to -33 mL, p<0.001). CONCLUSIONS: These findings suggest that telomere dysfunction may be associated with SSc-ILD progression and that PBL-TL measurement may be useful for stratifying risk for SSc-ILD progression.

Dermatomyositis autoantibodies: how can we maximize utility?

The past 15 years has seen significant advances in the characterization of myositis-specific autoantibodies (MSAs) and their associated phenotypes in patients with dermatomyositis (DM). As more careful studies are performed, it is clear that unique combinations of clinical and pathological phenotypes are associated with each MSA, despite the fact that there is considerable heterogeneity within antibody classes as well as overlap across the groups. Because risk for interstitial lung disease (ILD), internal malignancy, adverse disease trajectory, and, potentially response to therapy differ by DM MSA group, a deeper understanding of MSAs and validation and standardization of assays used for detection are critical for optimizing diagnosis and treatment. Like any test, the diagnostic sensitivity and specificity of assays for various MSAs is not perfect. Currently tests for MSAs are helpful at minimum for a clinician to assess relative risk or contribute to diagnosis and perhaps counsel the appropriate patient about what to expect. With international standardization and larger studies it is likely that more antibody tests will make their way into formal schemata for diagnosis and actionable risk assessment in DM. In this review, we summarize key considerations for interpreting the clinical and pathologic associations with MSA in DM and identify critical gaps in knowledge and practice that will maximize their clinical utility and utility for understanding disease pathogenesis.

A systematic review and meta-analysis to inform cancer screening guidelines in idiopathic inflammatory myopathies.

OBJECTIVES: To identify clinical factors associated with cancer risk in the idiopathic inflammatory myopathies (IIMs) and to systematically review the existing evidence related to cancer screening. METHODS: A systematic literature search was carried out on Medline, Embase and Scopus. Cancer risk within the IIM population (i.e. not compared with the general population) was expressed as risk ratios (RR) for binary variables and weighted mean differences (WMD) for continuous variables. Evidence relating to cancer screening practices in the IIMs were synthesized via narrative review. RESULTS: Sixty-nine studies were included in the meta-analysis. DM subtype (RR 2.21), older age (WMD 11.19), male sex (RR 1.53), dysphagia (RR 2.09), cutaneous ulceration (RR 2.73) and anti-transcriptional intermediary factor-1 gamma positivity (RR 4.66) were identified as being associated with significantly increased risk of cancer. PM (RR 0.49) and clinically amyopathic DM (RR 0.44) subtypes, Raynaud's phenomenon (RR 0.61), interstitial lung disease (RR 0.49), very high serum creatine kinase (WMD -1189.96) or lactate dehydrogenase (WMD -336.52) levels, and anti-Jo1 (RR 0.45) or anti-EJ (RR 0.17) positivity were identified as being associated with significantly reduced risk of cancer. Nine studies relating to IIM-specific cancer screening were included. CT scanning of the thorax, abdomen and pelvis appeared to be effective in identifying underlying asymptomatic cancers. CONCLUSION: Cancer risk factors should be evaluated in patients with IIM for risk stratification. Screening evidence is limited but CT scanning could be useful. Prospective studies and consensus guidelines are needed to establish cancer screening strategies in IIM patients.

Calcinosis is associated with ischemic manifestations and increased disability in patients with systemic sclerosis.

OBJECTIVE: Calcinosis is a debilitating complication of systemic sclerosis (SSc) with no effective treatments. We sought to identify clinical correlations and to characterize complications and disability associated with calcinosis in a multi-center, international cohort of SSc patients. METHODS: We established a cohort of 568 consecutive SSc patients who fulfill 2013 revised ACR/EULAR criteria at 10 centers within North America, Australia, and Mexico. Calcinosis was defined as subcutaneous calcium deposition by imaging and/or physical examination, or a clear history of extruded calcium. All patients completed the Scleroderma Health Assessment Questionnaire Disability Index and Cochin Hand Functional Scale. RESULTS: 215 (38%) patients had calcinosis. In multivariable analysis, disease duration (OR=1.24, p = 0.029), digital ischemia (OR=1.8, p = 0.002) and Acro-osteolysis (OR=2.97, p = 0.008) were significantly associated with calcinosis. In the subset of patients with bone densitometry (n = 68), patients with calcinosis had significantly lower median T-scores than patients without (-2.2 vs. -1.7, p = 0.004). The most common location of calcinosis lesions was the hands (70%), particularly the thumbs (19%) with decreasing frequency moving to the fifth fingers (8%). The most common complications were tenderness (29% of patients) and spontaneous extrusion of calcinosis through the skin (20%), while infection was rare (2%). Disability and hand function were worse in patients with calcinosis, particularly if locations in addition to the fingers/thumbs were involved. CONCLUSIONS: We confirmed a strong association between calcinosis and digital ischemia. Calcinosis in SSc patients most commonly affects the hands and is associated with a high burden of disability and hand dysfunction.

Increased Mortality in Asians With Systemic Sclerosis in Northern California.

OBJECTIVE: The objective of this study is to evaluate racial/ethnic differences in disease manifestations and survival in a US cohort of patients with systemic sclerosis (SSc), with a focus on Asian patients. METHODS: A retrospective cohort study was conducted among Kaiser Permanente Northern California adults with an incident SSc diagnosis by a rheumatologist from 2007 to 2016, confirmed by a chart review to fulfill 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria. Self-reported race/ethnicity was categorized as non-Hispanic white, Asian, Hispanic, and black. Disease manifestations and survival were compared, using white patients as the reference. RESULTS: A total of 609 patients with incident SSc were identified: 89% were women, and 81% had limited cutaneous SSc, with a mean age at diagnosis of 55.4 ± 14.8 years. The racial/ethnic distribution was 51% non-Hispanic white (n = 310), 25% Hispanic (n = 154), 16% Asian (n = 96), and 8% black (n = 49). Compared with white patients, black patients had a greater prevalence of diffuse disease (14.5% vs. 44.9%; P < 0.001), and Asians had higher rates of anti-U1-RNP antibodies (32.1% vs. 11.9%; P = 0.005). Nine-year overall survival rates following SSc diagnosis were lower in Asian (52.3%), black (52.2%), and Hispanic patients (68.2%) compared with white patients (75.8%). Pulmonary hypertension and infections were the leading causes of death in Asian patients. Asian race was associated with higher mortality on univariable (hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.08-2.99]; P = 0.020) and multivariable analyses (HR 1.80 [95% CI 0.99-3.16]; P = 0.047) when adjusting for age, sex, body mass index, cutaneous subtype, smoking status, interstitial lung disease, pulmonary hypertension, renal crisis, and malabsorption syndrome. CONCLUSION: Asian patients with SSc in this US cohort had increased mortality compared with white patients. These patients warrant close monitoring for disease progression.

Distinct dermatomyositis populations are detected with different autoantibody assay platforms.

OBJECTIVES: To compare autoantibody-defined dermatomyositis sub-populations using immunoprecipitation-based assays, a commercially available line immunoblot assay and alternate commercial ELISA assays. METHODS: Banked plasma from 261 carefully phenotyped dermatomyositis patients was studied. Immunoprecipitation-based assays were used to detect antibodies against Mi2, TIF1-γ MDA5, NXP2, SAE1 and PM-Scl, while anti-Jo1 antibodies were assayed using ELISA. These data were compared with that obtained using a commercial line immunoblot, and, additionally, for Mi2, TIF1-γ, MDA5, commercially available ELISA kits. Test agreement was measured using Cohen's kappa statistic, and phenotypic differences between differentially identified groups are described. RESULTS: Line immunoblot, immunoprecipitation, and ELISA detected increasingly larger nested pools of anti-TIF1-γ samples, with increasing frequency of concurrent anti-Mi2 reactivity and decreasing incidence of malignancy. Line immunoblot and immunoprecipitation showed fair concordance for identifying anti-NXP2 antibodies (Cohen's kappa=0.71) but very good agreement for identifying antibodies against Mi2, MDA5, and SAE1 (Cohen's κ=0.9, 0.94, 0.88, respectively). Anti-PM-Scl results showed moderate agreement (Cohen's κ=0.48) between immunoblot and immunoprecipitation. CONCLUSIONS: Our results demonstrate that for some specificities, especially anti-TIF1-γ, antibody results obtained using different assay platforms vary, and identify significantly different patient populations. These findings highlight the need for standard adoption of carefully validated platforms to detect dermatomyositis autoantibodies.

Clinical factors associated with cutaneous histopathologic findings in dermatomyositis.

BACKGROUND: Common histopathologic findings in cutaneous dermatomyositis include vacuolar interface with dyskeratosis, mucin, and perivascular inflammation. Data examining the relationships between these and other histologic abnormalities, or their dependence on biopsy site, and medications are limited. METHODS: Using 228 dermatomyositis skin biopsies and statistical analyses including Chi-squared analyses, calculations of relative risk, and adjusted generalized estimating equation regressions, we investigated relationships between 14 histopathologic findings and the impact of clinical factors on these findings. RESULTS: In biopsies taken from sites of visible rash, interface dermatitis was seen in 91%, and 95% had at least one of perivascular inflammation, mucin, or basal vacuolization. Vascular abnormalities were not closely associated with epidermal or inflammatory findings. Concomitant prednisone significantly decreased the odds of basal vacuolization (odds ratio [OR] = 0.34, 95% confidence interval [CI]: 0.12-0.98, P-value = 0.05), perivascular inflammation (OR = 0.19, 95% CI: 0.07-0.53, P-value = 0.002), and vessel damage (OR = 0.81, 95% CI: 0.68-0.96, P-value = 0.02). CONCLUSION: Vasculopathy and classic findings of interface dermatitis may be driven by unique pathways in dermatomyositis. Corticosteroid use may impact skin biopsy findings. There is a need for clinicopathologic correlation when diagnosing dermatomyositis.