Real-world effectiveness of golimumab in adult patients with rheumatoid arthritis, psoriatic arthritis, and axial spondyloarthritis and an inadequate response to initial TNFi therapy in Greece: the GO-BEYOND prospective, observational study.

The impact of golimumab (GLM) on remission or low disease activity (LDA) was evaluated in patients with moderate-to-severe rheumatoid arthritis (RA), progressive psoriatic arthritis (PsA), or severe axial spondyloarthritis (axSpA), who failed previous treatment for their rheumatic disease with one initial tumor necrosis factor α inhibitor (TNFi). This is a multicenter, prospective, real-world observational 18-month study, conducted in Greece. The primary endpoint, assessed at 6 months, included the proportion of patients attaining LDA and/or remission (Disease Activity Score for 28 joints based on C-reactive protein [DAS28-CRP] ≤ 3.2), minimal disease activity (MDA; MDA criteria), and moderate disease activity (Bath Ankylosing Spondylitis Disease Activity Index [BASDAI] score 4-7), respectively. Other endpoints evaluated the persistence to GLM treatment and its impact on patients' work productivity (Work Productivity and Activity Impairment [WPAI] instrument) and quality of life (QoL; EuroQoL5 dimensions 3 levels [EQ-5D-3L] questionnaire). Descriptive statistics, the Wilcoxon signed-rank test, and Kaplan-Meier method were used for analyses. At 6 months, LDA was achieved by 46.4% of patients with RA, MDA by 57.1% of patients with PsA, and BASDAI 4-7 by 24.1% of patients with axSpA. For all study patients, persistence rates on GLM were high (85.1-93.7%) over 18 months; all WPAI domain scores and the EQ-5D-3L index score improved significantly (p < 0.001) from baseline to 18 months. GLM treatment was effective in patients with RA, PsA, or axSpA who had failed previous treatment with one TNFi and led to significant WPAI and QoL improvements. Persistence rates were high. Trial registration number and date of registration: As per the local regulations the study has been registered at the national registry for non-interventional studies https://www.dilon.sfee.gr/studiesp_d.php?meleti_id=MK8259-6995 .

The effects of golimumab on patient centric outcomes amongst rheumatoid arthritis patients in Greece. The GO-Q study.

This study aimed at assessing the impact of golimumab on health-related quality of life (HRQoL) and other patient-reported outcomes (PROs) in patients with rheumatoid arthritis (RA) in real-world settings. GO-Q was an observational, prospective, 12-month study, which recruited patients with moderate-to-severely active RA initiating golimumab treatment per label in rheumatology clinics and private practices. Primary endpoint was the change in PROs [EuroQol-5 Dimensions-3 Levels (EQ-5D-3L) questionnaire, Health Assessment Questionnaire Disease Index (HAQ-DI), and Work Productivity and Activity Index for RA (WPAI:RA)] after 12 months of treatment. Other endpoints included Disease Activity Score for 28 joints with erythrocyte sedimentation rate (DAS28-ESR), healthcare resource utilization, and golimumab adherence. Changes in continuous variables from baseline were evaluated with the paired t test. One hundred forty-five patients were recruited. The mean [standard deviation (SD)] EQ-5D-3L index increased significantly at 12 months versus baseline [from 0.427 (0.206) to 0.801 (0.229); p < 0.0001], with changes as early as 3 and 6 months (both p < 0.0001). Accordingly, there were statistically significant changes in all WPAI:RA domains from baseline to 3, 6, and 12 months (p < 0.0001). Patients' function improved gradually from the third month until the end of follow-up (p < 0.0001 for all time-points). Thirty (27.3%) and 60 (54.6%) patients achieved remission (DAS28-ESR < 2.6) and low disease activity (DAS28-ESR ≤ 3.2), respectively, at 12 months. Adherence rate to golimumab was high (mean [SD] 90.3% (7.5) at 12 months). In patients with moderate-to-severely active RA, golimumab significantly improved HRQoL, physical function, and work productivity and activity, with improvements in disease activity over 12 months in real-world settings.

Gravitational Test beyond the First Post-Newtonian Order with the Shadow of the M87 Black Hole.

The 2017 Event Horizon Telescope (EHT) observations of the central source in M87 have led to the first measurement of the size of a black-hole shadow. This observation offers a new and clean gravitational test of the black-hole metric in the strong-field regime. We show analytically that spacetimes that deviate from the Kerr metric but satisfy weak-field tests can lead to large deviations in the predicted black-hole shadows that are inconsistent with even the current EHT measurements. We use numerical calculations of regular, parametric, non-Kerr metrics to identify the common characteristic among these different parametrizations that control the predicted shadow size. We show that the shadow-size measurements place significant constraints on deviation parameters that control the second post-Newtonian and higher orders of each metric and are, therefore, inaccessible to weak-field tests. The new constraints are complementary to those imposed by observations of gravitational waves from stellar-mass sources.

Testing General Relativity with Accretion-Flow Imaging of Sgr A

The Event Horizon Telescope is a global, very long baseline interferometer capable of probing potential deviations from the Kerr metric, which is believed to provide the unique description of astrophysical black holes. Here, we report an updated constraint on the quadrupolar deviation of Sagittarius A^{*} within the context of a radiatively inefficient accretion flow model in a quasi-Kerr background. We also simulate near-future constraints obtainable by the forthcoming eight-station array and show that in this model already a one-day observation can measure the spin magnitude to within 0.005, the inclination to within 0.09°, the position angle to within 0.04°, and the quadrupolar deviation to within 0.005 at 3σ confidence. Thus, we are entering an era of high-precision strong gravity measurements.

Resolved magnetic-field structure and variability near the event horizon of Sagittarius A.

Near a black hole, differential rotation of a magnetized accretion disk is thought to produce an instability that amplifies weak magnetic fields, driving accretion and outflow. These magnetic fields would naturally give rise to the observed synchrotron emission in galaxy cores and to the formation of relativistic jets, but no observations to date have been able to resolve the expected horizon-scale magnetic-field structure. We report interferometric observations at 1.3-millimeter wavelength that spatially resolve the linearly polarized emission from the Galactic Center supermassive black hole, Sagittarius A*. We have found evidence for partially ordered magnetic fields near the event horizon, on scales of ~6 Schwarzschild radii, and we have detected and localized the intrahour variability associated with these fields.

Kerr black holes are not unique to general relativity.

Considerable attention has recently focused on gravity theories obtained by extending general relativity with additional scalar, vector, or tensor degrees of freedom. In this Letter, we show that the black-hole solutions of these theories are essentially indistinguishable from those of general relativity. Thus, we conclude that a potential observational verification of the Kerr metric around an astrophysical black hole cannot, in and of itself, be used to distinguish between these theories. On the other hand, it remains true that detection of deviations from the Kerr metric will signify the need for a major change in our understanding of gravitational physics.

Probes and Tests of Strong-Field Gravity with Observations in the Electromagnetic Spectrum.

Neutron stars and black holes are the astrophysical systems with the strongest gravitational fields in the universe. In this article, I review the prospect of using observations of such compact objects to probe some of the most intriguing general relativistic predictions in the strong-field regime: the absence of stable circular orbits near a compact object and the presence of event horizons around black-hole singularities. I discuss the need for a theoretical framework, within which future experiments will provide detailed, quantitative tests of gravity theories. Finally, I summarize the constraints imposed by current observations of neutron stars on potential deviations from general relativity.

Constraints on braneworld gravity models from a kinematic limit on the age of the black hole XTE J1118+480.

In braneworld gravity models with a finite anti-de Sitter space (AdS) curvature in the extra dimension, the AdS/conformal field theory correspondence leads to a prediction for the lifetime of astrophysical black holes that is significantly smaller than the Hubble time, for asymptotic curvatures that are consistent with current experiments. Using the recent measurements of the position, three-dimensional spatial velocity, and mass of the black hole XTE J1118+480, I calculate a lower limit on its kinematic age of > or =11 Myr (95% confidence). This translates into an upper limit for the asymptotic AdS curvature in the extra dimensions of <0.08 mm, which significantly improves the limit obtained by table top experiments of sub mm gravity.

Local model for angular-momentum transport in accretion disks driven by the magnetorotational instability.

We develop a local model for the exponential growth and saturation of the Reynolds and Maxwell stresses in turbulent flows driven by the magnetorotational instability. We first derive equations that describe the effects of the instability on the growth and pumping of the stresses. We highlight the relevance of a new type of correlations that couples the dynamical evolution of the Reynolds and Maxwell stresses and plays a key role in developing and sustaining the magnetorotational turbulence. We then supplement these equations with a phenomenological description of the triple correlations that lead to a saturated turbulent state. We show that the steady-state limit of the model describes successfully the correlations among stresses found in numerical simulations of shearing boxes.

Towards new tests of strong-field gravity with measurements of surface atomic line redshifts from neutron stars.

In contrast to gravity in the weak-field regime, which has been subject to numerous experimental tests, gravity in the strong-field regime is largely unconstrained by observations. We show that gravity theories that pass solar system tests, but that diverge from general relativity in the strong-field regime, predict neutron stars with significantly different properties than their general relativistic counterparts. The range of redshfits of surface atomic lines predicted by such theories is significantly wider than the uncertainty introduced by our lack of knowledge of the equation of state of ultradense matter. Measurements of such lines with x-ray observatories can thus put new constraints on strong-field gravity.