Trial of Intravenous Immune Globulin in Dermatomyositis.

BACKGROUND: Intravenous immune globulin (IVIG) for the treatment of dermatomyositis has not been extensively evaluated. METHODS: We conducted a randomized, placebo-controlled trial involving patients with active dermatomyositis. The patients were assigned in a 1:1 ratio to receive IVIG at a dose of 2.0 g per kilogram of body weight or placebo every 4 weeks for 16 weeks. The patients who received placebo and those without confirmed clinical deterioration while receiving IVIG could enter an open-label extension phase for another 24 weeks. The primary end point was a response, defined as a Total Improvement Score (TIS) of at least 20 (indicating at least minimal improvement) at week 16 and no confirmed deterioration up to week 16. The TIS is a weighted composite score reflecting the change in a core set of six measures of myositis activity over time; scores range from 0 to 100, with higher scores indicating greater improvement. Key secondary end points included at least moderate improvement (TIS ≥40) and major improvement (TIS ≥60), and change in score on the Cutaneous Dermatomyositis Disease Area and Severity Index. RESULTS: A total of 95 patients underwent randomization: 47 patients were assigned to the IVIG group, and 48 to the placebo group. At 16 weeks, 79% of the patients in the IVIG group (37 of 47) and 44% of those in the placebo group (21 of 48) had a TIS of at least 20 (difference, 35 percentage points; 95% confidence interval, 17 to 53; P<0.001). The results with respect to the secondary end points, including at least moderate improvement and major improvement, were generally in the same direction as the results of the primary end-point analysis, except for the change in creatine kinase level (an individual core measure of the TIS), which did not differ meaningfully between the two groups. Over 40 weeks, 282 treatment-related adverse events occurred in the IVIG group, including headache (in 42% of patients), pyrexia (in 19%), and nausea (in 16%). A total of 9 serious adverse events that were considered to be related to IVIG occurred, including 6 thromboembolic events. CONCLUSIONS: In this 16-week trial involving adults with dermatomyositis, the percentage of patients with a response of at least minimal improvement based on a composite score of disease activity was significantly greater among those who received IVIG than among those who received placebo. IVIG was associated with adverse events, including thromboembolism. (Funded by Octapharma Pharmazeutika; ProDERM ClinicalTrials.gov number, NCT02728752.).

Treatment of Systemic Sclerosis-associated Interstitial Lung Disease: Evidence-based Recommendations. An Official American Thoracic Society Clinical Practice Guideline.

Background: Interstitial lung disease (ILD) is a significant cause of morbidity and mortality in patients with systemic sclerosis (SSc). To date, clinical practice guidelines regarding treatment for patients with SSc-ILD are primarily consensus based. Methods: An international expert guideline committee composed of 24 individuals with expertise in rheumatology, SSc, pulmonology, ILD, or methodology, and with personal experience with SSc-ILD, discussed systematic reviews of the published evidence assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach. Predetermined conflict-of-interest management strategies were applied, and recommendations were made for or against specific treatment interventions exclusively by the nonconflicted panelists. The confidence in effect estimates, importance of outcomes studied, balance of desirable and undesirable consequences of treatment, cost, feasibility, acceptability of the intervention, and implications for health equity were all considered in making the recommendations. This was in accordance with the American Thoracic Society guideline development process, which is in compliance with the Institute of Medicine standards for trustworthy guidelines. Results: For treatment of patients with SSc-ILD, the committee: 1) recommends the use of mycophenolate; 2) recommends further research into the safety and efficacy of (a) pirfenidone and (b) the combination of pirfenidone plus mycophenolate; and 3) suggests the use of (a) cyclophosphamide, (b) rituximab, (c) tocilizumab, (d) nintedanib, and (e) the combination of nintedanib plus mycophenolate. Conclusions: The recommendations herein provide an evidence-based clinical practice guideline for the treatment of patients with SSc-ILD and are intended to serve as the basis for informed and shared decision making by clinicians and patients.

Factors associated with physical function among people with systemic sclerosis: a SPIN cohort cross-sectional study.

OBJECTIVES: To compare physical function in systemic sclerosis (SSc, scleroderma) to general population normative data and identify associated factors. METHODS: Scleroderma Patient-centered Intervention Network Cohort participants completed the Physical Function domain of the Patient-Reported Outcomes Measurement Information System Version 2 upon enrolment. Multivariable linear regression was used to assess associations of sociodemographic, lifestyle, and disease-related variables. RESULTS: Among 2,385 participants, mean physical function T-score (43.7, SD = 8.9) was ∼2/3 of a standard deviation (SD) below the US general population (mean = 50, SD = 10). Factors associated in multivariable analysis included older age (-0.74 points per SD years, 95% CI -0.78 to -1.08), female sex (-1.35, -2.37 to -0.34), fewer years of education (-0.41 points per SD in years, -0.75 to -0.07), being single, divorced, or widowed (-0.76, -1.48 to -0.03), smoking (-3.14, -4.42 to -1.85), alcohol consumption (0.79 points per SD drinks per week, 0.45-1.14), BMI (-1.41 points per SD, -1.75 to -1.07), diffuse subtype (-1.43, -2.23 to -0.62), gastrointestinal involvement (-2.58, -3.53 to -1.62), digital ulcers (-1.96, -2.94 to -0.98), moderate (-1.94, -2.94 to -0.93) and severe (-1.76, -3.24 to -0.28) small joint contractures, moderate (-2.10, -3.44 to -0.76) and severe (-2.54, -4.64 to -0.44) large joint contractures, interstitial lung disease (-1.52, -2.27 to -0.77), pulmonary arterial hypertension (-3.72, -4.91 to -2.52), rheumatoid arthritis (-2.10, -3.64 to -0.56) and idiopathic inflammatory myositis (-2.10, -3.63 to -0.56). CONCLUSION: Physical function is impaired for many individuals with SSc and associated with multiple disease factors.

Immune Checkpoint Inhibitor-Associated Remitting Seronegative Symmetrical Synovitis With Pitting Edema: Description of a New Entity by CanRIO.

OBJECTIVE: Remitting seronegative symmetrical synovitis with pitting edema (RS3PE) is characterized by symmetrical synovitis with pitting edema and negative rheumatoid factor (RF). It has been described in a setting of malignancy, suggesting a paraneoplastic association. With the increasing use of immune checkpoint inhibitors (ICIs) for the treatment of cancers and emergence of immune-related adverse events (irAEs), our objective was to identify and describe cases of ICI-associated RS3PE (ICI-RS3PE) and compare them to non-ICI-RS3PE. METHODS: The Canadian Research Group of Rheumatology in Immuno-Oncology (CanRIO) network is a collaboration of Canadian rheumatologists with experience in the management of patients with rheumatic irAEs (Rh-irAEs). Standardized data on adult patients with Rh-irAE have been collected as part of retrospective and prospective cohorts. In this study, detailed information on all cases of ICI-RS3PE from both cohorts were extracted and analyzed. RESULTS: We identified 11 cases of ICI-RS3PE. The most frequently observed malignancy was nonsmall cell lung cancer (4 of 11), followed by malignant melanoma (2 of 11) and cutaneous squamous cell carcinoma (2 of 11). The median time to onset of ICI-RS3PE was 26 weeks from ICI start and 52 weeks from diagnosis of malignancy. Seven patients had stable cancer prior to onset of ICI-RS3PE, 3 had partial response, and 1 had complete response. All patients received glucocorticoids. Conventional synthetic disease-modifying antirheumatic drugs (csDMARD) were needed in 10 patients. CONCLUSION: ICI-RS3PE may be an independent Rh-irAE, separate from paraneoplastic RS3PE. The symptoms of ICI-RS3PE responded well to glucocorticoids, but concomitant treatment with csDMARDs may be necessary.

Addressing dispersion in mis-measured multivariate binomial outcomes: A novel statistical approach for detecting differentially methylated regions in bisulfite sequencing data.

Motivated by a DNA methylation application, this article addresses the problem of fitting and inferring a multivariate binomial regression model for outcomes that are contaminated by errors and exhibit extra-parametric variations, also known as dispersion. While dispersion in univariate binomial regression has been extensively studied, addressing dispersion in the context of multivariate outcomes remains a complex and relatively unexplored task. The complexity arises from a noteworthy data characteristic observed in our motivating dataset: non-constant yet correlated dispersion across outcomes. To address this challenge and account for possible measurement error, we propose a novel hierarchical quasi-binomial varying coefficient mixed model, which enables flexible dispersion patterns through a combination of additive and multiplicative dispersion components. To maximize the Laplace-approximated quasi-likelihood of our model, we further develop a specialized two-stage expectation-maximization (EM) algorithm, where a plug-in estimate for the multiplicative scale parameter enhances the speed and stability of the EM iterations. Simulations demonstrated that our approach yields accurate inference for smooth covariate effects and exhibits excellent power in detecting non-zero effects. Additionally, we applied our proposed method to investigate the association between DNA methylation, measured across the genome through targeted custom capture sequencing of whole blood, and levels of anti-citrullinated protein antibodies (ACPA), a preclinical marker for rheumatoid arthritis (RA) risk. Our analysis revealed 23 significant genes that potentially contribute to ACPA-related differential methylation, highlighting the relevance of cell signaling and collagen metabolism in RA. We implemented our method in the R Bioconductor package called "SOMNiBUS."

Agreement between local and central anti-synthetase antibodies detection: results from the Classification Criteria of Anti-Synthetase Syndrome project biobank.

OBJECTIVES: The CLASS (Classification Criteria of Anti-Synthetase Syndrome) project is a large international multicentre study that aims to create the first data-driven anti-synthetase syndrome (ASSD) classification criteria. Identifying anti-aminoacyl tRNA synthetase antibodies (anti-ARS) is crucial for diagnosis, and several commercial immunoassays are now available for this purpose. However, using these assays risks yielding false-positive or false-negative results, potentially leading to misdiagnosis. The established reference standard for detecting anti-ARS is immunoprecipitation (IP), typically employed in research rather than routine autoantibody testing. We gathered samples from participating centers and results from local anti-ARS testing. As an "ad-interim" study within the CLASS project, we aimed to assess how local immunoassays perform in real-world settings compared to our central definition of anti-ARS positivity. METHODS: We collected 787 serum samples from participating centres for the CLASS project and their local anti-ARS test results. These samples underwent initial central testing using RNA-IP. Following this, the specificity of ARS was reconfirmed centrally through ELISA, line-blot assay (LIA), and, in cases of conflicting results, protein-IP. The sensitivity, specificity, positive likelihood ratio and positive and negative predictive values were evaluated. We also calculated the inter-rater agreement between central and local results using a weighted κ co-efficient. RESULTS: Our analysis demonstrates that local, real-world detection of anti-Jo1 is reliable with high sensitivity and specificity with a very good level of agreement with our central definition of anti-Jo1 antibody positivity. However, the agreement between local immunoassay and central determination of anti-non-Jo1 antibodies varied, especially among results obtained using local LIA, ELISA and "other" methods. CONCLUSIONS: Our study evaluates the performance of real-world identification of anti-synthetase antibodies in a large cohort of multi-national patients with ASSD and controls. Our analysis reinforces the reliability of real-world anti-Jo1 detection methods. In contrast, challenges persist for anti-non-Jo1 identification, particularly anti-PL7 and rarer antibodies such as anti-OJ/KS. Clinicians should exercise caution when interpreting anti-synthetase antibodies, especially when commercial immunoassays test positive for non-anti-Jo1 antibodies.

Capillary pathology with prominent basement membrane reduplication is the hallmark histopathological feature of scleromyositis.

AIMS: We aim to perform ultrastructural and histopathological analysis of muscle biopsies from a large group of systemic sclerosis (SSc) patients, including some with early/mild SSc features, and examine whether capillary pathology differentiates 'scleromyositis' (SM) from other auto-immune myositis (AIM) subsets. METHODS: Muscle biopsies from a total of 60 SM patients and 43 AIM controls from two independent cohorts were examined by electron microscopy, collagen-4 immunofluorescence (Col4IF) and routine light microscopy. RESULTS: Ultrastructural examination revealed prominent capillary basement membrane (BM) reduplication (4+ layers in >50% of capillaries) in 65% of SM vs 0% of AIM controls (p < 0.001). In SM cases without prominent BM reduplication, capillary dilation was the most distinctive feature, present in 8% of capillaries in SM vs 2% in controls (p = 0.001). Accumulation of ensheathed pericyte processes was another characteristic feature of SM and closely correlated with the degree of BM reduplication (r = 0.833, p < 0.001). On light microscopy, BM marker Col4IF revealed more frequent capillary enlargement in SM than in controls (84% vs 21%, p < 0.001). SM cases were classified as non-inflammatory myopathy (36%), non-specific myositis (33%) or immune-mediated necrotizing myopathy (31%), but despite this histopathological heterogeneity, prominent BM reduplication remained a constant finding. In the 16 SM patients with early/mild SSc features, 63% showed prominent BM reduplication. CONCLUSIONS: These results show that capillary pathology, and in particular prominent capillary BM reduplication, is the hallmark histopathological feature of SM even in patients with early/mild SSc and support the concept of SM as an organ manifestation of SSc and a distinct subset of AIM.

Screening and management of subclinical interstitial lung disease in systemic sclerosis: an international survey.

OBJECTIVE: Interstitial lung disease (ILD) is the leading cause of mortality in SSc. Experts now recommend high-resolution CT (HRCT) screening in all SSc patients and treatment of subclinical ILD in SSc patients with high-risk phenotypes. We undertook an international survey to understand current screening and treatment practices in subclinical SSc-ILD. METHODS: An electronic REDCap survey was distributed to 611 general rheumatologists, 348 national and international SSc experts, 285 general respirologists and 57 ILD experts. RESULTS: One hundred and ninety-eight participants responded to the survey, including 135 (68%) rheumatologists and 54 (27%) respirologists. Over half (59%) of respondents routinely ordered HRCTs in all newly diagnosed SSc patients, although this practice was more common in Europe (83%), the USA (68%), Asia (73%) and Latin America (100%) compared with Canada (40%) and Australia (40%). Nearly half (48%) of respondents would not treat subclinical SSc-ILD, whereas 52% would treat or consider treatment. At least 70% would likely treat subclinical ILD in the setting of diffuse SSc, anti-topoisomerase-I autoantibodies, disease duration below 18 months, ground-glass opacities, oxygen desaturation, or significant ILD progression on imaging or pulmonary function tests. The majority (67%) of respirologists would not treat subclinical ILD. MMF was the preferred first-line drug for the treatment of subclinical SSc-ILD. CONCLUSION: This international survey highlights important regional variations in SSc-ILD screening and significant heterogeneity among rheumatologists and respirologists in the treatment of subclinical SSc-ILD. High-quality research addressing these questions is needed to produce evidence-based guidelines and harmonize the approach to identification and treatment of subclinical SSc-ILD.

Association between autoantibodies in systemic sclerosis and cancer in a national registry.

OBJECTIVE: A close temporal relationship between SSc onset and cancer has been reported in anti-RNA polymerase III-positive patients. We investigated the association between cancer and other SSc autoantibodies in a national SSc registry. METHODS: SSc patients enrolled in the Canadian Scleroderma Research Group registry from 2004 to 2019 were characterized according to autoantibodies to centromere, topoisomerase I/Scl70, RNA polymerase III, fibrillarin, Th/To (hPOP1), PM/Scl, Ku, NOR90, Ro52/TRIM21 and U1RNP. Logistic regression was used to examine the association between a close cancer-SSc interval and autoantibody status, adjusted for age, sex, race and smoking history. RESULTS: Of 1698 SSc patients, 1481 (87%) had available autoantibody data. Cancer was diagnosed within 2, 3 and 5 years of the first non-Raynaud manifestation in 1.3%, 2.1% and 3.5% of patients. The most frequent cancers diagnosed within 2 years were breast (33%), gynaecological (19%) and haematological (14%) cancers. The risk of cancer within 2 years was increased among anti-topoisomerase I [odds ratio (OR) 3.43, 95% CI: 1.04, 10.05] and anti-U1-RNP-positive patients (OR 5.54, 95% CI: 1.16, 20.40), but not with anti-RNA polymerase III. None of the anti-fibrillarin, Th/To, PM/Scl, Ku and NOR90-positive patients had cancer within 2 years. Patients with anti-centromere or none of the tested autoantibodies had numerically lower risks of developing cancer within two years. CONCLUSION: Synchronous cancer was rare in this large cohort of predominantly female and White SSc patients. The risk of cancer within 2 years was increased among anti-topoisomerase I and anti-U1-RNP-positive patients. Screening strategies guided by autoantibodies require further careful consideration.

Autoantibody profiles delineate distinct subsets of scleromyositis.

OBJECTIVE: Scleromyositis remains incompletely characterized owing in part to its heterogeneity. The purpose of this study was to explore the role of autoantibody profiles to define subsets of scleromyositis. METHODS: Subjects with scleromyositis from a prospective cohort were divided into three groups based on autoantibody profiles: subjects with SSc-specific autoantibodies (anti-centromere, -topoisomerase 1, -RNA polymerase III, -Th/To, -fibrillarin), subjects with SSc-overlap autoantibodies (anti-PM/Scl, -U1RNP, -Ku) and subjects without SSc-related autoantibodies. Clinical features, laboratory tests and histopathological findings were retrieved and compared between groups. RESULTS: Of 42 scleromyositis subjects (79% female, mean age at diagnosis 55 years, mean disease duration 3.5 years), 8 (19%) subjects had SSc-specific autoantibodies, 14 (33%) SSc-overlap autoantibodies and 20 (48%) had no SSc-related autoantibodies. One-third had no skin involvement, a finding more frequent in the SSc-overlap subjects and those without SSc-related autoantibodies. Proximal and distal weakness was common and head drop/bent spine was found in 50% of the SSc-specific and 35% of the subjects without SSc-related autoantibodies. Of note, the group without SSc-related autoantibodies had the only cases of severe cardiac systolic dysfunction (n = 1) and scleroderma renal crisis (n = 1), as well as three out of the four cancers and three out of the four deaths. CONCLUSION: In this carefully phenotyped series of scleromyositis subjects, absence of SSc-related autoantibodies was common and associated with distinct features and poor prognosis. Future studies are needed to validate these results and possibly identify novel autoantibodies or other biomarkers associated with scleromyositis.

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.

Glucosamine and lower mortality and cancer incidence: Selection bias in the observational studies.

BACKGROUND: Glucosamine is a widely used supplement to treat joint pain and osteoarthritis despite inconclusive randomized trial results on its effectiveness. In contrast, observational studies associate glucosamine with significant reductions in mortality and cancer incidence. We evaluated the extent of bias, particularly selection bias, to explain these surprising beneficial effects. METHODS: We searched the literature to identify all observational studies reporting on the effect of glucosamine use on major outcomes. RESULTS: We identified 11 observational studies, reporting a mean 16% reduction in all-cause mortality (hazard ratio [HR] 0.84, 95% CI: 0.81-0.87) with glucosamine use, as well as significant reductions in cancer incidence and other major diseases including cardiovascular, respiratory and diabetes. We show that these significant effects can result from selection bias due to collider stratification, as all studies used "prevalent" cohorts, where glucosamine use started before cohort entry, and where subjects agreed to join the cohorts. Our illustration of the bias using the UK Biobank publication involving a half-million subjects shows how a true rate ratio of mortality of 1.0 in the population can result in a biased rate ratio of 0.82 in the prevalent cohort. CONCLUSIONS: The observational studies reporting significant reductions in mortality, cancer incidence and other outcomes with glucosamine were affected by selection bias from collider stratification. In the absence of properly conducted observational studies that circumvent this bias by considering "new users", the studies to date cannot support the prescription of this supplement as a preventive measure for mortality, cancer, and other chronic diseases.

Preexisting autoimmune disease and immune-related adverse events associated with anti-PD-1 cancer immunotherapy: a national case series from the Canadian Research Group of Rheumatology in Immuno-Oncology.

BACKGROUND: Limited data are available on the safety and efficacy of immune checkpoint inhibitors (ICI) in patients with preexisting autoimmune diseases (PAD). METHODS: Retrospective study of patients with PAD referred for rheumatologic evaluation prior to starting or during immunotherapy between January 2013 and July 2019 from 10 academic sites across Canada. Data were extracted by chart review using a standardized form. RESULTS: Twenty-seven patients with PAD on ICI therapy were identified. The most common PADs were rheumatoid arthritis (30%), psoriasis/psoriatic arthritis (30%), inflammatory bowel disease (IBD, 15%) and axial spondyloarthritis (11%), and the most frequently observed cancers were lung cancer and melanoma. All patients received anti-PD-1 therapies, and 2 received additional sequential anti-CTLA-4 therapy. PAD exacerbations occurred in 52% over a median (IQR) follow-up of 11.0 (6.0-17.5) months, with 14% being severe, 57% requiring corticosteroids, 50% requiring immunosuppression and 14% requiring ICI discontinuation. Flares were generally more frequent and severe in patients who previously required more intensive immunosuppression (i.e., biologics). Flares occurred despite background immunosuppression at the time of ICI initiation. In patients with preexisting psoriasis, IBD and axial spondyloarthritis, rheumatic immune-related adverse events (irAEs), mostly polyarthritis and tenosynovitis, were frequently observed. Tumor progression was not associated with exposure to immunosuppressive drugs before or after ICI initiation and was numerically less frequent in patients with irAEs. CONCLUSION: PAD exacerbations in the context of ICI treatment are common, although generally mild, and occur despite background immunosuppression. Exacerbations are more frequent and severe in patients on more intensive immunosuppressive therapies pre-immunotherapy.

Barriers and facilitators to influenza and pneumococcal vaccine hesitancy in rheumatoid arthritis: a qualitative study.

OBJECTIVES: Immunization is an essential component of RA care. Nevertheless, vaccine coverage in RA is suboptimal. Contextual, individual and vaccine-related factors influence vaccine acceptance. However, barriers and facilitators of vaccination in RA are not well defined. The aim of this study was to assess perspectives of RA patients and healthcare professionals (HCPs) involved in RA care of barriers and facilitators regarding influenza and pneumococcal vaccines. METHODS: Eight focus groups (four with RA patients and four with HCPs) and eight semi-structured open-ended individual interviews with vaccine-hesitant RA patients were conducted. Data were audio recorded, transcribed verbatim and imported to MAXQDA software. Analysis using the framework of vaccine hesitancy proposed by the Strategic Advisory Group of Experts on Immunization was conducted. RESULTS: RA patients and HCPs reported common and specific barriers and facilitators to influenza vaccination that included contextual, individual and/or group and vaccine- and/or vaccination-specific factors. A key contextual influence on vaccination was patients' perception of the media, pharmaceutical industry, authorities, scientists and the medical community at large. Among the individual-related influences, experiences with vaccination, knowledge/awareness and beliefs about health and disease prevention were considered to impact vaccine acceptance. Vaccine-related factors including concerns about vaccine side effects such as RA flares, the safety of new formulations, the mechanism of action, access to vaccines and costs associated with vaccination were identified as actionable barriers. CONCLUSION: Acknowledging RA patients' perceived barriers to influenza and pneumococcal vaccination and implementing specific strategies to address them might increase vaccination coverage in this population.

Determinants and functional impacts of diaphragmatic involvement in patients with inclusion body myositis.

BACKGROUND: We evaluated the functional consequences of diaphragm involvement in patients with inclusion body myositis (IBM). METHODS: Ultrasound diaphragm thickening fraction (TFdi), lung function and dyspnea levels were compared between IBM patients and matched controls. Patients with IBM were grouped into "low" and "high" diaphragm activity based on TFdi values (with cutoff value being the lowest observed TFdi in the control group), and clinical characteristics were compared between groups. RESULTS: 20 IBM patients were included. TFdi was significantly lower in patients and correlated with time since symptom onset (rho = 0.74, P < .001). Patients had significantly lower forced vital capacity and higher dyspnea scores than controls. IBM patients with "low" diaphragm activity (n = 9) had lower 6-min walking distance, higher resting and exertional dyspnea and a larger positional decrease in vital capacity (all P ≤ .03) than patients with 'high' activity. Timed Up and Go time and St. George's Respiratory Questionnaire were not different between groups. CONCLUSIONS: Diaphragm involvement in IBM is related to disease duration and has detrimental effects on lung function, dyspnea and exercise capacity. Further studies are required to investigate its potential as a therapeutic target.

A novel statistical method for modeling covariate effects in bisulfite sequencing derived measures of DNA methylation.

Identifying disease-associated changes in DNA methylation can help us gain a better understanding of disease etiology. Bisulfite sequencing allows the generation of high-throughput methylation profiles at single-base resolution of DNA. However, optimally modeling and analyzing these sparse and discrete sequencing data is still very challenging due to variable read depth, missing data patterns, long-range correlations, data errors, and confounding from cell type mixtures. We propose a regression-based hierarchical model that allows covariate effects to vary smoothly along genomic positions and we have built a specialized EM algorithm, which explicitly allows for experimental errors and cell type mixtures, to make inference about smooth covariate effects in the model. Simulations show that the proposed method provides accurate estimates of covariate effects and captures the major underlying methylation patterns with excellent power. We also apply our method to analyze data from rheumatoid arthritis patients and controls. The method has been implemented in R package SOMNiBUS.

Wintering bird communities are tracking climate change faster than breeding communities.

Global climate change is driving species' distributions towards the poles and mountain tops during both non-breeding and breeding seasons, leading to changes in the composition of natural communities. However, the degree of season differences in climate-driven community shifts has not been thoroughly investigated at large spatial scales. We compared the rates of change in the community composition during both winter (non-breeding season) and summer (breeding) and their relation to temperature changes. Based on continental-scale data from Europe and North America, we examined changes in bird community composition using the community temperature index (CTI) approach and compared the changes with observed regional temperature changes during 1980-2016. CTI increased faster in winter than in summer. This seasonal discrepancy is probably because individuals are less site-faithful in winter, and can more readily shift their wintering sites in response to weather in comparison to the breeding season. Regional long-term changes in community composition were positively associated with regional temperature changes during both seasons, but the pattern was only significant during summer due to high annual variability in winter communities. Annual changes in community composition were positively associated with the annual temperature changes during both seasons. Our results were broadly consistent across continents, suggesting some climate-driven restructuring in both European and North American avian communities. Because community composition has changed much faster during the winter than during the breeding season, it is important to increase our knowledge about climate-driven impacts during the less-studied non-breeding season.

Immunosuppression does not prevent severe gastrointestinal tract involvement in systemic sclerosis.

OBJECTIVES: We aimed to test the hypothesis that exposure to immunosuppression in early systemic sclerosis (SSc) could modify the risk of developing new onset severe gastrointestinal (GIT) involvement. METHODS: A total of 762 subjects with <3 years of disease duration and without severe GIT disease at baseline study visit were identified from combined longitudinal cohort data from the Canadian Scleroderma Research Group (CSRG) and Australian Scleroderma Interest Group (ASIG). The primary exposure was ever use of methotrexate, cyclophosphamide, mycophenolate mofetil and/or azathioprine during the study period. Severe GIT disease was defined as: 1-malabsorption, 2-hyperalimentation, 3-pseudo-obstruction, and/or 4-≥10% weight loss in association with the use of antibiotics for bacterial overgrowth or oesophageal stricture. The change in the hazard of severe GIT disease due to exposure was estimated using a marginal structural Cox proportional hazards model fit by inverse probability of treatment weights (IPTW) to address potential confounding. RESULTS: Study subjects were 81.5% female, had a mean age of 53.7±13.0 years and mean disease duration at baseline of 1.4±0.8 years. During a mean follow-up of 4.0±2.6 years, severe GIT involvement developed in 11.6% of the 319 subjects exposed to immunosuppression and in 6.8% of the 443 unexposed subjects. In an IPTW-adjusted analysis, exposure to immunosuppression was not associated with severe GIT disease (weighted hazard ratio 0.91, 95% confidence interval 0.52-1.58). CONCLUSIONS: In this large inception SSc cohort, the risk of severe GIT involvement was not modified by exposure to immunosuppression.

An epigenome-wide association study of total serum immunoglobulin E concentration.

Immunoglobulin E (IgE) is a central mediator of allergic (atopic) inflammation. Therapies directed against IgE can alleviate hay fever and allergic asthma. Genetic association studies have not yet identified novel therapeutic targets or pathways underlying IgE regulation. We therefore surveyed epigenetic associations between serum IgE concentrations and methylation at loci concentrated in CpG islands genome wide in 95 nuclear pedigrees, using DNA from peripheral blood leukocytes. We validated positive results in additional families and in subjects from the general population. Here we show replicated associations--with a meta-analysis false discovery rate less than 10(-4)--between IgE and low methylation at 36 loci. Genes annotated to these loci encode known eosinophil products, and also implicate phospholipid inflammatory mediators, specific transcription factors and mitochondrial proteins. We confirmed that methylation at these loci differed significantly in isolated eosinophils from subjects with and without asthma and high IgE levels. The top three loci accounted for 13% of IgE variation in the primary subject panel, explaining the tenfold higher variance found compared with that derived from large single-nucleotide polymorphism genome-wide association studies. This study identifies novel therapeutic targets and biomarkers for patient stratification for allergic diseases.

Association between immunosuppressive therapy and course of mild interstitial lung disease in systemic sclerosis.

OBJECTIVE: Interstitial lung disease (ILD) is a leading cause of mortality in SSc. Little is known about the benefits of immunosuppressive drugs in mild ILD. Our aim was to determine whether use of CYC or MMF was associated with an improved ILD course in patients with normal or mildly impaired lung function. METHODS: A retrospective cohort of SSc subjects with ILD, disease duration below seven years and no exposure to CYC or MMF prior to the baseline visit was constructed from the Canadian Scleroderma Research Group registry. Subjects were categorized as having mild ILD if baseline forced vital capacity (FVC % predicted) was >85%. The primary exposure was any use of CYC or MMF at the baseline visit. FVC at one year was compared between exposed and unexposed subjects, using multivariate linear regression. RESULTS: Out of 294 eligible SSc-ILD subjects, 116 met criteria for mild ILD. In this subgroup, mean (s.d.) disease duration was 3.7 (2.0) years. Thirteen (11.2%) subjects were exposed to CYC or MMF at baseline. The one-year FVC was higher in exposed subjects compared with unexposed subjects, by a difference of 8.49% (95% CI: 0.01-16.98%). None of the exposed subjects experienced clinically meaningful progression over two years, whereas 24.6% of unexposed subjects did. CONCLUSION: In this real-world setting, CYC/MMF exposure at baseline was associated with higher FVC values and a lower risk of progression among subjects with mild ILD. These data suggest a window of opportunity to preserve lung function in SSc-ILD.