374 research outputs found
Neutron diffraction study of stripe order in La(2)NiO(4+d) with d=2/15
We report a detailed neutron scattering study of the ordering of spins and
holes in oxygen-doped La(2)NiO(4.133). The single-crystal sample exhibits the
same oxygen-interstitial order but better defined charge-stripe order than that
studied previously in crystals with d = 0.125. In particular, charge order is
observed up to a temperature at least twice that of the magnetic transition,
T_m = 110.5 K. On cooling through T_m, the wave vector \epsilon, equal to half
the charge-stripe density within an NiO(2) layer, jumps discontinuously from
1/3 to 0.2944. It continues to decrease with further cooling, showing several
lock-in transitions on the way down to low temperature. To explain the observed
lock-ins, a model is proposed in which each charge stripe is centered on either
a row of Ni or a row of O ions. The model is shown to be consistent with the
l-dependence of the magnetic peak intensities and with the relative intensities
of the higher-order magnetic satellites. Analysis of the latter also provides
evidence that the magnetic domain walls (charge stripes) are relatively narrow.
In combination with a recent study of magnetic-field-induced effects, we find
that the charge stripes are all O-centered at T>T_m, with a shift towards Ni
centering at T<T_m. Inferences concerning the competing interactions
responsible for the the temperature dependence of \epsilon and the localization
of charge within the stripes are discussed.Comment: ReVTeX, 17 2-col pages, 10 eps figs. embedded with psfig, submitted
to Phys. Rev.
New insights into the impact of neuro-inflammation in rheumatoid arthritis.
Rheumatoid arthritis (RA) is considered to be, in many respects, an archetypal autoimmune disease that causes activation of pro-inflammatory pathways resulting in joint and systemic inflammation. RA remains a major clinical problem with the development of several new therapies targeted at cytokine inhibition in recent years. In RA, biologic therapies targeted at inhibition of tumor necrosis factor alpha (TNFα) have been shown to reduce joint inflammation, limit erosive change, reduce disability and improve quality of life. The cytokine TNFα has a central role in systemic RA inflammation and has also been shown to have pro-inflammatory effects in the brain. Emerging data suggests there is an important bidirectional communication between the brain and immune system in inflammatory conditions like RA. Recent work has shown how TNF inhibitor therapy in people with RA is protective for Alzheimer's disease. Functional MRI studies to measure brain activation in people with RA to stimulus by finger joint compression, have also shown that those who responded to TNF inhibition showed a significantly greater activation volume in thalamic, limbic, and associative areas of the brain than non-responders. Infections are the main risk of therapies with biologic drugs and infections have been shown to be related to disease flares in RA. Recent basic science data has also emerged suggesting that bacterial components including lipopolysaccharide induce pain by directly activating sensory neurons that modulate inflammation, a previously unsuspected role for the nervous system in host-pathogen interactions. In this review, we discuss the current evidence for neuro-inflammation as an important factor that impacts on disease persistence and pain in RA
Biologics registers in RA: methodological aspects, current role and future applications
The beginning of the 21st century saw a biopharmaceutical revolution in the treatment of inflammatory rheumatic diseases, particularly rheumatoid arthritis. The fast-evolving use of biologic therapies highlighted the need to develop registers at national and international levels with the aim of collecting long-term data on patient outcomes. Over the past 15 years, many biologics registers have contributed a wealth of data and provided robust and reliable evidence on the use, effectiveness and safety of these therapies. The unavoidable challenges posed by the continuous introduction of new therapies, particularly with regard to understanding their long-term safety, highlights the importance of learning from experience with established biologic therapies. In this Perspectives article, the role of biologics registers in bridging the evidence gap between efficacy in clinical trials and real-world effectiveness is discussed, with a focus on methodological aspects of registers, their unique features and challenges and their role going forward
Treatment benefit or survival of the fittest: what drives the time-dependent decrease in serious infection rates under TNF inhibition and what does this imply for the individual patient?
EULAR COVID-19 registry: lessons learnt and future considerations.
Future disease outbreaks of epidemic proportion are inevitable. Advance planning and preparation is essential to mitigate future public health risks; the WHO emphasises the importance of in-depth evaluation of response to and lessons learnt from a national/international pandemic.1 Research is critical to an informed, evidence-based response, therefore establishing pandemic research study protocols, systems to manage and report data, and rapid response teams are considered key to well-prepared, accelerated research in public health emergencies.2
Establishing international data collection registries poses many challenges, which are only amplified in the urgent nature of a global pandemic. The aim of this manuscript is to reflect on the successes and challenges of the European Alliance of Associations for Rheumatology (EULAR) COVID-19 registry3 to better understand how the rheumatology community (and other disease-specific communities) can be better prepared for rapid response research in the future. In particular, we consider the successes and challenges of the registry, what can be learnt from this experience, and what procedures and resources should be established and strengthened now in preparation for future pandemics
Rheumatoid arthritis - treatment: 180. Utility of Body Weight Classified Low-Dose Leflunomide in Japanese Rheumatoid Arthritis
Background: In Japan, more than 20 rheumatoid arthritis (RA) patients died of interstitial pneumonia (IP) caused by leflunomide (LEF) were reported, but many of them were considered as the victims of opportunistic infection currently. In this paper, efficacy and safety of low-dose LEF classified by body weight (BW) were studied. Methods: Fifty-nine RA patients were started to administrate LEF from July 2007 to July 2009. Among them, 25 patients were excluded because of the combination with tacrolimus, and medication modification within 3 months before LEF. Remaining 34 RA patients administered 20 to 50 mg/week of LEF were followed up for 1 year and enrolled in this study. Dose of LEF was classified by BW (50 mg/week for over 50 kg, 40 mg/week for 40 to 50 kg and 20 to 30 mg/week for under 40 kg). The average age and RA duration of enrolled patients were 55.5 years old and 10.2 years. Prednisolone (PSL), methotrexate (MTX) and etanercept were used in 23, 28 and 2 patients, respectively. In case of insufficient response or adverse effect, dosage change or discontinuance of LEF were considered. Failure was defined as dosages up of PSL and MTX, or dosages down or discontinuance of LEF. Last observation carried forward method was used for the evaluation of failed patients at 1 year. Results: At 1 year after LEF start, good/ moderate/ no response assessed by the European League Against Rheumatism (EULAR) response criteria using Disease Activity Score, including a 28-joint count (DAS28)-C reactive protein (CRP) were showed in 14/ 10/ 10 patients, respectively. The dosage changes of LEF at 1 year were dosage up: 10, same dosage: 5, dosage down: 8 and discontinuance: 11 patients. The survival rate of patients in this study was 23.5% (24 patients failed) but actual LEF continuous rate was 67.6% (11 patients discontinued) at 1 year. The major reason of failure was liver dysfunction, and pneumocystis pneumonia was occurred in 1 patient resulted in full recovery. One patient died of sepsis caused by decubitus ulcer infection. DAS28-CRP score was decreased from 3.9 to 2.7 significantly. Although CRP was decreased from 1.50 to 0.93 mg/dl, it wasn't significant. Matrix metalloproteinase (MMP)-3 was decreased from 220.0 to 174.2 ng/ml significantly. Glutamate pyruvate transaminase (GPT) was increased from 19 to 35 U/l and number of leukocyte was decreased from 7832 to 6271 significantly. DAS28-CRP, CRP, and MMP-3 were improved significantly with MTX, although they weren't without MTX. Increase of GPT and leukopenia were seen significantly with MTX, although they weren't without MTX. Conclusions: It was reported that the risks of IP caused by LEF in Japanese RA patients were past IP history, loading dose administration and low BW. Addition of low-dose LEF is a potent safe alternative for the patients showing unsatisfactory response to current medicines, but need to pay attention for liver function and infection caused by leukopenia, especially with MTX. Disclosure statement: The authors have declared no conflicts of interes
Response to: ‘Correspondence on ‘Factors associated with COVID-19-related death in people with rheumatic diseases: results from the COVID-19 Global Rheumatology Alliance physician reported registry’ by Arnaud and Devilliers
Evaluation of the RABBIT Risk Score for serious infections
Objective: To evaluate the Rheumatoid Arthritis Observation of Biologic Therapy (RABBIT) Risk Score for serious infections in patients with rheumatoid arthritis (RA).
Methods: The RABBIT Risk Score for serious infections was developed in 2011 on a cohort of RA patients enrolled in the German biologics register RABBIT between 2001 and 2007. To evaluate this score, we used data from patients enrolled in RABBIT after 1 January 2009. Expected numbers of serious infections and expected numbers of patients with at least one serious infection per year were calculated by means of the RABBIT Risk Score and compared with observed numbers in the evaluation sample.
Results: The evaluation of the score in an independent cohort of 1522 RA patients treated with tumour necrosis factor α (TNFα) inhibitors and 1468 patients treated with non-biological disease-modifying antirheumatic drugs (DMARDs) showed excellent agreement between observed and expected rates of serious infections. For patients exposed to TNF inhibitors, expected as well as observed numbers of serious infections were 3.0 per 100 patient-years (PY). For patients on non-biological DMARDs the expected and observed numbers were 1.5/100 PY and 1.8/100 PY, respectively. The score was highly predictive in groups of patients with low as well as with high infection risk.
Conclusions: The RABBIT Risk Score is a reliable instrument which determines the risk of serious infection in individual patients based on clinical and treatment information. It helps the rheumatologist to balance benefits and risks of treatment, to avoid high-risk treatment combinations and thus to make informed clinical decisions
SARS-CoV-2 infection after vaccination in patients with inflammatory rheumatic and musculoskeletal diseases
Characteristics and Outcomes of People With Gout Hospitalized Due to COVID-19: Data From the COVID-19 Global Rheumatology Alliance Physician-Reported Registry
Objective: To describe people with gout who were diagnosed with coronavirus disease 2019 (COVID-19) and hospitalized and to characterize their outcomes. Methods: Data on patients with gout hospitalized for COVID-19 between March 12, 2020, and October 25, 2021, were extracted from the COVID-19 Global Rheumatology Alliance registry. Descriptive statistics were used to describe the demographics, comorbidities, medication exposures, and COVID-19 outcomes including oxygenation or ventilation support and death. Results: One hundred sixty-three patients with gout who developed COVID-19 and were hospitalized were included. The mean age was 63 years, and 85% were male. The majority of the group lived in the Western Pacific Region (35%) and North America (18%). Nearly half (46%) had two or more comorbidities, with hypertension (56%), cardiovascular disease (28%), diabetes mellitus (26%), chronic kidney disease (25%), and obesity (23%) being the most common. Glucocorticoids and colchicine were used pre-COVID-19 in 11% and 12% of the cohort, respectively. Over two thirds (68%) of the cohort required supplemental oxygen or ventilatory support during hospitalization. COVID-19-related death was reported in 16% of the overall cohort, with 73% of deaths documented in people with two or more comorbidities. Conclusion: This cohort of people with gout and COVID-19 who were hospitalized had high frequencies of ventilatory support and death. This suggests that patients with gout who were hospitalized for COVID-19 may be at risk of poor outcomes, perhaps related to known risk factors for poor outcomes, such as age and presence of comorbidity
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