Reduction of anterior uveitis flares in patients with axial spondyloarthritis on certolizumab pegol treatment: final 2-year results from the multicenter phase IV C-VIEW study

Introduction: Acute anterior uveitis (AAU), affecting up to 40% of patients with axial spondyloarthritis (axSpA), risks permanent visual deficits if not adequately treated. We report 2-year results from C-VIEW, the first study to prospectively investigate certolizumab pegol (CZP) on AAU in patients with active axSpA at high risk of recurrent AAU. Patients and methods: C-VIEW (NCT03020992) was a 104-week (96 weeks plus 8-week safety follow-up), open-label, multicenter study. Eligible patients had active axSpA, human leukocyte antigen-B27 (HLA-B27) positivity and a history of recurrent AAU (⩾2 AAU flares in total; ⩾1 in the year prior to baseline). Patients received CZP 400 mg at weeks 0, 2 and 4, then 200 mg every 2 weeks to week 96. The primary efficacy endpoint was the AAU flare event rate during 96 weeks’ CZP versus 2 years pre-baseline. Results: Of 115 enrolled patients, 89 initiated CZP (male: 63%; radiographic/non-radiographic axSpA: 85%/15%; mean disease duration: 9.1 years); 83 completed week 96. There was a significant 82% reduction in AAU flare event rate during CZP versus pre-baseline [rate ratio (95% confidence interval): 0.18 (0.12–0.28), p < 0.001]. One hundred percent and 59.6% of patients experienced ⩾1 and ⩾2 AAU flares pre-baseline, respectively, compared to 20.2% and 11.2% during treatment. Age, sex and axSpA population subgroup analyses were consistent with the primary analysis. There were substantial improvements in axSpA disease activity with no new safety signal identified. Conclusion: CZP treatment significantly reduced AAU flare event rate in patients with axSpA and a history of AAU, indicating CZP is a suitable treatment option for patients at risk of recurrent AAU. Trial Registration ClinicalTrials.gov: NCT03020992, URL: https://clinicaltrials.gov/ct2/show/NCT03020992

A quasar microlensing event towards J1249+3449?

ABSTRACT We show that the optical flare event discovered by Graham et al. towards the active galactic nucleus J1249+3449 is fully consistent with being a quasar microlensing event due to a ≃0.1 M⊙ star, although other explanations, such as that, mainly supported by Graham et al., of being the electromagnetic counterpart associated with a binary black hole merger, cannot be completely excluded at present.

Using radio triangulation to understand the origin of two subsequent type II radio bursts

Context. Eruptive events such as coronal mass ejections (CMEs) and flares accelerate particles and generate shock waves which can arrive at Earth and can disturb the magnetosphere. Understanding the association between CMEs and CME-driven shocks is therefore highly important for space weather studies. Aims. We present a study of the CME/flare event associated with two type II bursts observed on September 27, 2012. The aim of the study is to understand the relationship between the observed CME and the two distinct shock wave signatures. Methods. The multiwavelength study of the eruptive event (CME/flare) was complemented with radio triangulation of the associated radio emission and modelling of the CME and the shock wave employing MHD simulations. Results. We found that, although temporal association between the type II bursts and the CME is good, the low-frequency type II (LF-type II) burst occurs significantly higher in the corona than the CME and its relationship to the CME is not straightforward. The analysis of the EIT wave (coronal bright front) shows the fastest wave component to be in the southeast quadrant of the Sun. This is also the quadrant in which the source positions of the LF-type II were found to be located, probably resulting from the interaction between the shock wave and a streamer. Conclusions. The relationship between the CME/flare event and the shock wave signatures is discussed using the temporal association, as well as the spatial information of the radio emission. Further, we discuss the importance and possible effects of the frequently non-radial propagation of the shock wave.

Property studies of “loner” flares of gamma-ray blazars

We search through $\gamma$-ray data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope and find 24 blazars (or candidates) that have a single clear flare event in their 9.5 yr long-term light curves. We define these events as loner flares since each flare stands out significantly above the relatively stable, low-flux light curve. We analyze the LAT data in detail for these 24 sources. The flares in 10 of them are primarily due to a single sharp peak, for which we study by fitting with two different analytic functions. The time durations thus determined for the sharp peaks are in a range of 4–$25\:$d. The $\gamma$-ray spectra of the 24 blazar sources can be described with a power-law or a log-parabola function. We obtain their spectral properties in the flaring and quiescent states, and find that in the flares 16 of the sources have harder emission, three have softer emission, and the other five keep the same emission. We discuss a possible correlation between the differences in photon index in the quiescent and flaring states and photon indices in quiescence. In addition, the sharp peak flares seem to have a tendency of having long time durations and hard emission, possibly related to their physical origin in a blazar jet. Studies of more similar flares will help establish these possible features.

Statistical analysis on X-ray flares from the nucleus and HST-1 knot in the M87 jet

ABSTRACT The statistical properties of X-ray flares from two separate locations (nucleus and HST-1) in the M87 jet are investigated to reveal the physical origin of the flares. We analyse the archival Chandra data for M87, and identify 14 flares in the nucleus and nine flares in HST-1. The peak intensity (IP) and the flaring duration time (Tfl) for each flare are obtained. It is found that the distributions of both IP and Tfl for the nucleus obey a power law form with a similar index. A similar result is also obtained for HST-1, and no significant inconsistency between the nucleus and HST-1 is found for the indices. Similar to solar X-ray flares, the power-law distributions of the flare event parameters can be well explained by a self-organized criticality system, which are triggered by magnetic reconnection. Our results suggest that the flares from nucleus and HST-1 are possibly triggered by magnetic reconnection process. The consistent indices for the distributions of IP and Tfl in the nucleus and HST-1 indicate that the dimensions of the energy dissipation of the magnetic reconnection are identical in the two regions. A strong correlation between the flares in the two regions also suggests a similar physical origin for the flares.