Giant Cell Arteritis

Corticosteroid therapy has always been the standard treatment for giant cell arteritis (GCA), with very good initial clinical efficacy but a high relapse rate when it declines. The target population of this condition, often elderly, is particularly exposed to the numerous undesirable effects of corticosteroid therapy, and this especially as its duration lengthens with the re-increases of doses according to relapses: metabolic complications, osteo-muscular , infectious or neuropsychiatric. Investigators propose to compare prospectively the results of a "conventional" corticosteroid regimen as recommended by European societies, to those of a "lighter and / or shorter" scheme, inspired by recent North American trials. , including the largest prospective global study in the field. Investigators hypothesize non-inferiority of the lightened regimen for relapse rate without relapse at S52, but with a decrease in treatment-related adverse events whose cumulative doses should be lower. Investigators therefore plan to include prospectively over 3 years 150 patients, 75 for each of the two arms, with a newly diagnosed ACG. A randomization of the treatment arm will be performed and a predefined pattern of cortisone adapted to body weight will be given to the patient. Relapse rates, maintenance of remission, cumulative doses of cortisone and adverse effects of treatment will be analyzed at the 52nd week of the introduction of corticosteroid therapy. An interim analysis is planned at S28.

Background: \- Vasculitis is a group of diseases that inflame and damage blood vessels and tissue. It can cause many medical problems. Few tests can diagnose the disease, and none can reliably predict a relapse. Researchers want to study people s genes and follow people over time to see how the disease affects them. Objective: \- To learn the signs, symptoms, imaging tests, genetic markers, and blood tests that can help identify people with vasculitis and predict what will happen to them over time. Eligibility: * People age 3 and older who have or are thought to have vasculitis, or are related to someone with it. * Healthy volunteers. Design: * Participants will be evaluated by a doctor who has expertise caring for patients with vasculitis. * Participants will give a blood sample. Some will give a urine sample. * Some participants may have brushings or biopsies taken from the inside lining of the nose. * Images of participants blood vessels may be taken using scans. For some scans, participants will lie on a table that moves in and out of a cylinder that takes pictures. For some scans, a contrast agent may be injected into an arm vein. Other scans may use a radioactive form of sugar. Healthy minors will not have scans. * Some participants will answer questionnaires. - Some participants will have their tests done at NIH. Others will have their doctor take the blood, saliva, or cheek swab samples and send them to NIH. * Some participants will have one visit lasting 1-2 (but sometimes up to 4) days. Some participants may have follow-up visits every 3 - 6 months, indefinitely.

The goal of this open-label clinical trial is to evaluate the efficacy of AzaFol-PET/CT in the diagnosis of GCA (giant cell arteritis), to compare AzaFol- with 2-\[18F\]FDG-PET/CT, and to assess the safety and tolerability of AzaFol in subjects with suspicion of GCA. Participants will undergo AzaFol-PET/CT imaging at a single timepoint.

Giant cell arteritis (GCA) is an inflammatory disease of large and medium arteries that can cause irreversible vision loss. Glucocorticoids (GCs) rapidly suppress inflammation, but diagnostic imaging tests such as temporal artery ultrasound or biopsy often become falsely negative within days of treatment. The optic nerve sheath diameter (ONSD), measurable by ocular ultrasound, reflects perineural edema and may serve as a quantitative biomarker of ocular inflammation in GCA. The SONIC-TIME study (Early Temporal Dynamics of Optic Nerve Sheath Diameter After Glucocorticoid Therapy in Giant Cell Arteritis) is a single-center, prospective observational substudy embedded within SONIC-GCA (NCT05749094) at Hôpital du Sacré-Cœur de Montréal. It aims to characterize how rapidly ONSD decreases after GC initiation and how this trajectory relates to cumulative GC exposure, intravenous methylprednisolone, and early use of steroid-sparing therapies. Sixty participants with newly diagnosed GCA will undergo serial optic nerve sheath ultrasound, blood tests (CRP, ESR), and when feasible, temporal artery ultrasound over the first two months of therapy (Days 3, 7, 10, 14, 21, 28, and Month 2). No experimental treatments are given; all participants receive standard-of-care therapy. The primary objective is to quantify the percent change in mean ONSD from baseline to Day 28. Secondary objectives include modeling ONSD change over time, assessing associations with cumulative steroid dose and inflammatory markers, and estimating the time to normalization below the SONIC-GCA cutoff. Findings will define the optimal imaging window and refine the diagnostic and monitoring role of optic nerve ultrasound in GCA.

Ultrasound evaluation of the temporal and axillary arteries is currently well recognized in the field of giant cell arteritis (GCA), a disease primarily affecting medium- and large-caliber vessels. Structural ultrasound abnormalities are now well described in this pathology, but their association with relapse and clinical concordance is unknown. There is currently a follow-up score (the OGUS score) for medium- and large-caliber arteries that could also predict the clinical course of the disease.

In this double-blinded randomised placebo-controlled clinical trial, the aim is to determine the effect of supplemental hydrocortisone compared with placebo during mild to moderate physical or mental stress on health related quality of life in patients with polymyalgia rheumatica (PMR)/giant cell arteritis (GCA) on ongoing low-dose prednisolone diagnosed with glucocorticoid-induced adrenal insufficiency. The main emphasis is on fatigue (primary outcome) and daily variation hereof during periods of stress.

To facilitate clinical, basic science, and translational research projects involving the study of rheumatic diseases.

This randomized, double-blind, placebo-controlled trial will seek to determine the efficacy of abatacept in GCA. To examine this objective, 62 eligible patients who have newly diagnosed or relapsing GCA within 8 weeks prior to screening will be randomized at a 1:1 ratio to receive subcutaneous abatacept 125mg/week or placebo. Patients who achieve remission will remain on their blinded assignment for 12 months at which time abatacept/placebo will be stopped. Patients who do not achieve remission by Month 3, who experience a relapse within the first 12 months will have the option of receiving open-label abatacept for a maximum of 12 months.

The purpose of this study is to collect existing tissue specimens from subjects enrolled in Vasculitis Clinical Research Consortium (VCRC) studies. Analysis of these tissue specimens and linked clinical data collected through VCRC studies may lead to the identification and development of a series of translational research projects. Results of these studies will provide vasculitis researchers with insight into the causes of these diseases and generate new ideas for diagnostic tests and therapies, and will be of great interest to the larger communities of researchers investigating vasculitis and other autoimmune, inflammatory, and vascular diseases.

The purpose of this study is to identify genes that increase the risk of developing vasculitis, a group of severe diseases that feature inflammation of blood vessels. Results of these studies will provide vasculitis researchers with insight into the causes of these diseases and generate new ideas for diagnostic tests and therapies, and will be of great interest to the larger communities of researchers investigating vasculitis and other autoimmune, inflammatory, and vascular diseases.

Giant cell arteritis (GCA) (or Horton's disease) is a segmental and focal inflammatory arteritis affecting large and medium-sized arteries. Its incidence is estimated at 17.8/100,000 in subjects over 50 years old (and 46/100,000 in subjects over 70 years old). This disease remains a severe pathology due in particular to its vascular, ophthalmological, neurological, cardiac and aortic complications. In case of suspected CAG, management is a real therapeutic emergency. Indeed, only corticosteroid therapy started as early as possible can prevent the occurrence of these complications. The gold standard for the diagnosis of CAG has long been the temporal artery biopsy, but imaging is now considered as a 1st line diagnostic examination for the diagnosis of CAG according to the EULAR 2018 recommendations. Notably, temporal artery MRI has excellent sensitivity and specificity for diagnosis. However, the high diagnostic performance of MRI has been achieved by performing 3D T1 black blood and fat saturation sequences in high resolution (\<0.7mm), which are not accessible in all centers in France and worldwide. The realization of identical sequences with a lower resolution could allow a greater generalization of these sequences and improve the diagnostic management of GCA patients, including in non-expert centers. The objective of our study is to investigate the diagnostic performance of several 3D T1 black blood and fat saturation sequences for the diagnosis of GCA.

Long-term follow-up of aortal adverse events, as well as glucocortioid-associated adverse events in patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA).

The research study is being conducted to determine the utility of magnetic resonance imaging (MRI) in identifying inflammation of arteries supplying blood to the head, brain, and eyes. The target population includes patient with suspected giant cell arteritis (GCA; temporal arteritis).

The Sonographic Assessment of the Optic Nerve Sheath in Giant Cell Arteritis (SONIC-GCA) study will evaluate the performance of the optic nerve sheath diameter (ONSD), measured via ultrasound, to diagnose and monitor GCA. SONIC-GCA builds upon our previous pilot studies and will answer the following questions: 1. What is the performance of ONSD to identify patients with new-onset, active GCA? 2. Is ONSD useful for monitoring GCA relapses during follow-up? 3. What is the intra- and interobserver reliability of ONSD measurements? 4. Does ONSD differ between patients with and without GCA-related retinal findings?

The GCAIO study is an innovative, multimodal research initiative designed to enhance the understanding, diagnosis, and management of giant cell arteritis (GCA) and frequently associated polymyalgia rheumatica (PMR). This longitudinal study aims to dissect the complex immunological landscape and systemic manifestations of these conditions through a combination of diagnostic imaging and detailed immunological profiling. The study focuses on three primary objectives: (1) Identifying and analyzing cytokine profiles and immune cell phenotypes, employing techniques like flow cytometry, enzyme-linked immunosorbent assays (ELISA), and next-generation sequencing to predict disease activity and therapeutic responses. (2) Advancing diagnostic and monitoring capabilities through the application of novel and established imaging technologies, including MRI, optical coherence tomography angiography (OCTA), and ultrasound. These modalities aim to improve the detection of neuro-ophthalmological, cardiac, and aortic complications in GCA, potentially offering more precise monitoring and earlier diagnosis. (3) Enhancing the understanding of PMR within the context of GCA by exploring specific biomarkers and advanced imaging to refine diagnostic accuracy and treatment strategies, thus improving patient outcomes.

Longitudinal prospective multicenter Armenian registry of systemic autoimmune, autoinflammatory diseases with constitution of bio-banking.

A multi-centre observational study recruiting prospective and retrospective cohorts of patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). The primary aim is to find genetic determinants of GCA and PMR susceptibility, in order to yield novel insights into disease pathogenesis. A subset of the retrospective cohort is also enrolled in a post-marketing surveillance registry of patients eligible for, or receiving tocilizumab, to treat their relapsing or refractory GCA.

This observational study aims to enhance the description of the different ways Giant Cell Arteritis (GCA) affects vision. The latest technology and knowledge are used to improve how we diagnose and predict patient outcomes. GCA is the most frequent vasculitis, an inflammation of vessels, in older adults. It involves large and medium-sized arteries and causes ischemic alterations such as stroke and blindness, through damage of extracranial arteries. The primary objective is to compare the frequency of the various ocular findings between the main alterations of arteritic and non-arteritic aetiology, such as Arteritic Anterior Ischemic Optic Neuropathy (A-AION) Vs. Non-Arteritic Anterior Ischemic Optic Neuropathy (NA-AION) or Central Retinal Artery Occlusion (CRAO) from GCA Vs. from other causes, through a comprehensive clinical and instrumental evaluation.

Giant cell arteritis (GCA), also known as Horton's disease, is an inflammatory arteritis of the large and medium-sized arteries, with an estimated incidence of 17.8/100,000 in people over 50. The disease presents potential ophthalmological, neurological, cardiac and aortic vascular complications, making diagnosis an emergency in cases of suspected Horton's disease. only corticosteroid therapy started as early as possible can prevent these complications. Diagnosis has historically relied on temporal artery biopsy, but the recent ACR/EULAR 2022 classification criteria propose alternatives to this invasive examination, in particular imaging tests such as temporal artery ultrasound and PET scans. Although not included in these latest recommendations, high-definition wall MRI can also provide arguments in favor of this diagnosis, and avoid the need for a temporal artery biopsy, the sensitivity of which is only 75%. The investigators recently demonstrated in a prospective cohort that wall MRI, possibly coupled with temporal artery ultrasound or retinal angiography, was far superior to temporal artery biopsy in diagnostic performance. The main limitation of these imaging tests is the lack of data in the literature on the evolution of abnormalities over time, and in particular after initiation of oral corticosteroid therapy. This uncertainty makes it difficult to use these examinations to monitor disease activity, particularly in cases of suspected relapse, a frequent situation in which the clinician is regularly put at fault due to an often frustrating symptomatology and the possible absence of a frank biological inflammatory syndrome. The investigators propose to conduct a study aimed at describing the evolution of cranial vessel wall abnormalities on wall MRI and ultrasound by systematically repeating these examinations at 1 month, 3 months from the initial MRI performed at diagnosis, in addition to the follow-up performed as part of care at 6 and 12 months from diagnosis. In the event of a relapse in the intervening period, a new MRI scan can be performed and compared with the most recent MRI scan, to look for evidence of disease activity.

The longitudinal observational study aims to assess the impact of the microbiome especially the gut-microbiome in the emergence and course of giant cell arteritis (abbr. GCA) patients. At diagnosis and 6 month follow up we will analyze the oral, blood and gut microbiome from GCA patients and healthy controls. Thereby identified potential candidate biota will be further analyzed for possible interactions and influence on the immune system.

The goal of this clinical trial is to verify whether CHIP is correlated with the clinical, instrumental, and histological characteristics of GCA, and to characterize the pathogenetic effects of clonal hemopoiesis on vasculitis. The main objective of this study is to verify if clonal hematopoiesis of indeterminate potential (CHIP) affects GCA manifestations, course/response to therapies, and pathogenesis. Patients who are going to be diagnosed with GCA and for which a fast track is available for a rapid diagnostic work-up including pre-treatment temporal artery biopsy. Patients with CHIP will be identified and characterized by using whole exome sequencing from the peripheral blood samples. The presence and characteristics of CHIP will be correlated with baseline clinical, instrumental, and histologic GCA features.

The aim of this national pragmatic observational study is to investigate whether the use of new diagnostic imaging modalities facilitates disease stratification that can potentially predict treatment response, relapse risk and complications and hence guide management strategies to improve disease control and reduce disease and treatment related damage.