Objective To assess the safety and efficacy of rituximab in a randomized, double-blind, placebo-phase, trial of adult and pediatric myositis. Methods Adults with refractory polymyositis and adults and children with refractory dermatomyositis were enrolled. Entry criteria included muscle weakness and ≥2 additional abnormal core set measures (CSM) for adults. JDM patients required ≥ 3 abnormal CSM with or without muscle weakness. Patients were randomized to either ‘rituximab early’ or ‘rituximab late’ and glucocorticoid and immunosuppressive therapy were allowed at entry. The primary endpoint compared the time to achieve the preliminary International Myositis Assessment and Clinical Studies Group definition of improvement (DOI) between the 2 groups. The secondary endpoints were time to achieve ≥20% improvement in muscle strength, and the proportion of early and late rituximab patients achieving DOI at week 8. Results Among 200 randomized patients (76 PM/76 DM/48 JDM), 195 showed no difference in the time to DOI between the rituximab late (n=102) and rituximab early (n=93) groups (p=0.74, log rank) with a median time to DOI of 20.2 weeks and 20.0 weeks respectively. The secondary endpoints also did not significantly differ between the two treatment groups. However, 161 (83%) of randomized patients met the DOI and individual CSM improved in both groups throughout the 44-week trial. Conclusion Although there were no significant differences in the two treatment arms for the primary and secondary endpoints, 83% of refractory adult and juvenile myositis patients met the DOI. The role of B cell depleting therapies in myositis warrants further study with consideration for a different trial design.

Objective To compare the cumulative survival and event free survival in patients with Jo-1 versus non-Jo-1 anti-tRNA synthetase autoantibodies (anti-synAb). Methods Anti-synAb positive patients initially evaluated from 1985 to 2009 were included regardless of the connective tissue disease (CTD) diagnosis. Clinical data were extracted from a prospectively collected database and chart review. Survival between Jo-1 and non-Jo-1 was compared by log rank and Cox proportional hazards methods. Results 202 patients possessed anti-synAb: 122 Jo-1 and 80 non-Jo-1 (35 PL-12; 25 PL-7; 9 EJ; 6 KS; 5 OJ). The diagnoses at first visit for Jo-1 and non-Jo-1 patients were myositis in 83% and 40.0%, overlap or undifferentiated CTD in 17% and 47.5%, and systemic sclerosis in 0% and 12.5%, respectively (p<0.001). The median delay in diagnosis was 0.4 years in Jo-1 patients versus 1.0 year in non-Jo-1 patients (p<0.001). The most common causes of death in the overall cohort were pulmonary fibrosis in 49% and pulmonary hypertension in 11%. The 5- and 10-year unadjusted cumulative survival was 90% and 70% for Jo-1 patients, and 75% and 47% for non-Jo-1 patients ( p<0.005). The hazard ratio (HR) of non-Jo-1 patients compared with Jo-1 patients was 1.9 (p=0.01) for cumulative and 1.9 (p=0.008) for event free survival from diagnosis. Age at first diagnosis and diagnosis delay but not gender, ethnicity and CTD diagnosis influenced survival. Conclusions Non-Jo-1 anti-synAb positive patients have decreased survival compared with Jo-1 patients. The difference in survival may be partly attributable to a delay in diagnosis in the non-Jo-1 patients.

Ornithine decarboxylase (ODC) was converted from a protein with a short intracellular half-life in mammalian cells to a stable protein by truncating 37 residues at its carboxyl terminus. Cells expressing wild-type protein lost ODC activity with a half-life of approximately 1 hour. Cells expressing the truncated protein, however, retained full activity for at least 4 hours. Pulse-chase experiments in which immunoprecipitation and gel electrophoresis were used confirmed the stabilizing effect of the truncation. Thus, a carboxyl-terminal domain is responsible for the rapid intracellular degradation of murine ODC.

Rationale: Interstitial lung disease (ILD), a leading cause of morbidity and mortality in rheumatoid arthritis (RA), is highly prevalent, yet RA-ILD is underrecognized.Objectives: To identify clinical risk factors, autoantibodies, and biomarkers associated with the presence of RA-ILD.Methods: Subjects enrolled in Brigham and Women's Hospital Rheumatoid Arthritis Sequential Study (BRASS) and American College of Rheumatology (ACR) cohorts were evaluated for ILD. Regression models were used to assess the association between variables of interest and RA-ILD. Receiver operating characteristic curves were generated in BRASS to determine if a combination of clinical risk factors and autoantibodies can identify RA-ILD and if the addition of investigational biomarkers is informative. This combinatorial signature was subsequently tested in ACR. Measurements and Main Results:A total of 113 BRASS subjects with clinically indicated chest computed tomography scans (41% with a spectrum of clinically evident and subclinical RA-ILD) and 76 ACR subjects with research or clinical scans (51% with a spectrum of RA-ILD) were selected. A combination of age, sex, smoking, rheumatoid factor, and anticyclic citrullinated peptide antibodies was strongly associated with RA-ILD (areas under the curve, 0.88 for BRASS and 0.89 for ACR). Importantly, a combinatorial signature including matrix metalloproteinase 7, pulmonary and activation-regulated chemokine, and surfactant protein D significantly increased the areas under the curve to 0.97 (P = 0.002, BRASS) and 1.00 (P = 0.016, ACR). Similar trends were seen for both clinically evident and subclinical RA-ILD.Conclusions: Clinical risk factors and autoantibodies are strongly associated with the presence of clinically evident and subclinical RA-ILD on computed tomography scan in two independent RA cohorts. A biomarker signature composed of matrix metalloproteinase 7, pulmonary and activation-regulated chemokine, and surfactant protein D significantly strengthens this association. These findings may facilitate identification of RA-ILD at an earlier stage, potentially leading to decreased morbidity and mortality.Keywords: interstitial lung disease; rheumatoid arthritis; subclinical; biomarkers; risk prediction

Objective The aim was to identify the clinical and laboratory predictors of clinical improvement in a cohort of myositis patients treated with rituximab. Methods We analyzed data for 195 myositis patients [75 adult polymyositis/72 adult dermatomyositis/48 juvenile dermatomyositis (JDM)] in the Rituximab in Myositis trial. Clinical improvement was defined as 20% improvement in at least 3 of 6 core set measures (CSM) of disease activity: physician and patient/parent global disease activity, manual muscle testing, physical function, muscle enzymes, and extramuscular disease activity. We analyzed the association of the following baseline variables with improvement: myositis clinical subgroup, demographics, myositis damage, clinical and laboratory parameters, CSM, rituximab treatment, and myositis autoantibodies (anti-synthetase, -Mi-2, -SRP, -TIF1-γ, -MJ, other and no autoantibodies). All measures were univariately assessed for association with improvement using time-to-event analyses. A multivariable time-dependent proportional hazards model was used to evaluate the association of individual predictive factors with improvement. Results In the final multivariable model, the presence of an anti-synthetase [primarily anti-Jo-1 (HR 3.08, p<0.01)], anti-Mi-2 (HR 2.5, p<0.01), or other autoantibody (HR 1.4, p=0.14) predicted a shorter time to improvement compared to the autoantibody negative subset. Lower physician global damage (HR 2.32, p< 0.01) and JDM (vs. adult myositis, HR 2.45, p<0.01) also predicted improvement. Unlike the autoantibody subset, the predictive effect of physician global damage and JDM diminished by week 20. Rituximab treatment did not affect these associations. Conclusion The presence of an anti-synthetase and anti-Mi-2 autoantibodies, JDM subset and lower disease damage strongly predicted clinical improvement in refractory myositis patients.

Objective. Previous case series have examined the relationship between anti-Jo-1 antibody levels and myositis disease activity, demonstrating equivocal results. Using enzyme-linked immunosorbent assays (ELISAs) and novel measures of myositis disease activity, the current study was undertaken to systematically reexamine the association between anti-Jo-1 antibody levels and various disease manifestations of myositis.Methods. Serum anti-Jo-1 antibody levels were quantified using 2 independent ELISA methods, while disease activity was retrospectively graded using the Myositis Disease Activity Assessment Tool, which measures disease activity in 7 different organ systems via the Myositis Disease Activity Assessment Visual Analog Scale (VAS) and the Myositis Intention-to-Treat Index (MITAX) components. Spearman's rank correlation coefficients and mixed linear regression analysis were used to identify associations between anti-Jo-1 antibody levels and organ-specific disease activity in crosssectional and longitudinal analyses, respectively.Results. Cross-sectional assessment of 81 patients with anti-Jo-1 antibody revealed a modest correlation between the anti-Jo-1 antibody level and the serum creatine kinase (CK) level, as well as muscle and joint disease activity. Correlation coefficients were similar for CK levels (r s ‫؍‬ 0.38, P ‫؍‬ 0.002), myositis VAS (r s ‫؍‬ 0.36, P ‫؍‬ 0.002), and arthritis VAS (r s ‫؍‬ 0.40, P ‫؍‬ 0.001). In multiple regression analyses of 11 patients with serial samples, anti-Jo-1 antibody levels correlated significantly with CK levels (R 2 ‫؍‬ 0.65, P ‫؍‬ 0.0002), myositis VAS (R 2 ‫؍‬ 0.53, P ‫؍‬ 0.0008), arthritis VAS (R 2 ‫؍‬ 0.53, P ‫؍‬ 0.006), pulmonary VAS (R 2 ‫؍‬ 0.69, P ‫؍‬ 0.005), global VAS (R 2 ‫؍‬ 0.63, P ‫؍‬ 0.002), and global MITAX (R 2 ‫؍‬ 0.64, P ‫؍‬ 0.0003).Conclusion. In this large series of patients with idiopathic inflammatory myopathy, anti-Jo-1 antibody levels correlated modestly with muscle and joint disease, an association confirmed by a custom ELISA using recombinant human Jo-1. More striking associations emerged in a smaller longitudinal subset of patients that link anti-Jo-1 antibody levels to muscle, joint, lung, and global disease activity.

Objective. Using a combination of clinical, radiographic, functional, and serum protein biomarker assessments, this study was aimed at defining the prevalence and clinical characteristics of interstitial lung disease (ILD) in a large cohort of patients with antiJo-1 antibodies.Methods Interstitial lung disease (ILD) is an increasingly recognized complication of several systemic autoDrs.

Objective Interstitial lung disease (ILD) is a relatively common extraarticular manifestation of rheumatoid arthritis (RA) that contributes significantly to disease burden and excess mortality. The purpose of this study was to identify peripheral blood markers of RA-associated ILD that can facilitate earlier diagnosis and provide insight regarding the pathogenesis of this potentially devastating disease complication. Methods Patients with RA who were enrolled in a well-characterized Chinese identification cohort or a US replication cohort were subclassified as having RA–no ILD, RA–mild ILD, or RA–advanced ILD, based on high-resolution computed tomography scans of the chest. Multiplex enzyme-linked immunosorbent assays (ELISAs) and Luminex xMAP technology were used to assess 36 cytokines/chemokines, matrix metalloproteinases (MMPs), and acute-phase proteins in the identification cohort. Unadjusted and adjusted logistic regression models were used to quantify the strength of association between RA-ILD and biomarkers of interest. Results MMP-7 and interferon-γ–inducible protein 10 (IP-10)/CXCL10 were identified by multiplex ELISA as potential biomarkers for RA-ILD in 133 RA patients comprising the Chinese identification cohort (50 RA–no ILD, 41 RA-ILD, 42 RA–indeterminate ILD). The findings were confirmed by standard solid-phase sandwich ELISA in the Chinese identification cohort as well as an independent cohort of US patients with RA and different stages of ILD (22 RA–no ILD, 49 RA-ILD, 15 RA–indeterminate ILD), with statistically significant associations in both unadjusted and adjusted logistic regression analyses. Conclusion Levels of MMP-7 and IP-10/CXCL10 are elevated in the serum of RA patients with ILD, whether mild or advanced, supporting their value as pathogenically relevant biomarkers that can contribute to noninvasive detection of this extraarticular disease complication.