A Randomized, Double-Blind Trial of Abatacept (CTLA-4Ig) for the Treatment of Giant Cell Arteritis

Effectiveness of janus kinase inhibitors in relapsing giant cell arteritis in real-world clinical practice and review of the literature

BACKGROUND

A substantial proportion of patients with giant cell arteritis (GCA) relapse despite standard therapy with glucocorticoids, methotrexate and tocilizumab. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway is involved in the pathogenesis of GCA and JAK inhibitors (JAKi) could be a therapeutic alternative. We evaluated the effectiveness of JAKi in relapsing GCA patients in a real-world setting and reviewed available literature.

METHODS

Retrospective analysis of GCA patients treated with JAKi for relapsing disease at thirteen centers in Spain and one center in United States (01/2017-12/2022). Outcomes assessed included clinical remission, complete remission and safety. Clinical remission was defined as the absence of GCA signs and symptoms regardless of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. Complete remission was defined as the absence of GCA signs and symptoms along with normal ESR and CRP values. A systematic literature search for other JAKi-treated GCA cases was conducted.

RESULTS

Thirty-five patients (86% females, mean age 72.3) with relapsing GCA received JAKi therapy (baricitinib, n = 15; tofacitinib, n = 10; upadacitinib, n = 10). Before JAKi therapy, 22 (63%) patients had received conventional synthetic immunosuppressants (e.g., methotrexate), and 30 (86%) biologics (e.g., tocilizumab). After a median (IQR) follow-up of 11 (6-15.5) months, 20 (57%) patients achieved and maintained clinical remission, 16 (46%) patients achieved and maintained complete remission, and 15 (43%) patients discontinued the initial JAKi due to relapse (n = 11 [31%]) or serious adverse events (n = 4 [11%]). A literature search identified another 36 JAKi-treated GCA cases with clinical improvement reported for the majority of them.

CONCLUSIONS

This real-world analysis and literature review suggest that JAKi could be effective in GCA, including in patients failing established glucocorticoid-sparing therapies such as tocilizumab and methotrexate. A phase III randomized controlled trial of upadacitinib is currently ongoing (ClinicalTrials.gov ID NCT03725202).

Cranial involvement in giant cell arteritis

Since its first clinical description in 1890, extensive research has advanced our understanding of giant cell arteritis, leading to improvements in both diagnosis and management for affected patients. Imaging studies have shown that the disease frequently extends beyond the typical cranial arteries, also affecting large vessels such as the aorta and its proximal branches. Meanwhile, advances in comprehending the underlying pathophysiology of giant cell arteritis have given rise to numerous potential therapeutic agents, which aim to minimise the need for glucocorticoid treatment and prevent flares. Classification criteria for giant cell arteritis, as well as recommendations for management, imaging, and treat-to-target have been developed or updated in the last 5 years, and current research encompasses a broad spectrum covering basic, translational, and clinical research. In this Series paper, we aim to discuss the current understanding of giant cell arteritis with cranial manifestations, describe the clinical approach to this condition, and explore future directions in research and patient care.

Large vessel giant cell arteritis

Giant cell arteritis is the principal form of systemic vasculitis affecting people over 50. Large-vessel involvement, termed large vessel giant cell arteritis, mainly affects the aorta and its branches, often occurring alongside cranial giant cell arteritis, but large vessel giant cell arteritis without cranial giant cell arteritis can also occur. Patients mostly present with constitutional symptoms, with localising large vessel giant cell arteritis symptoms present in a minority of patients only. Large vessel giant cell arteritis is usually overlooked until clinicians seek to exclude it with imaging by ultrasonography, magnetic resonance angiography (MRA), computed tomography angiography (CTA), or [18F]fluorodeoxyglucose-PET-CT. Although the role of imaging in treatment monitoring remains uncertain, imaging by MRA or CTA is crucial for identifying aortic aneurysm formation during patient follow up. In this Series paper, we define the large vessel subset of giant cell arteritis and summarise its clinical challenges. Furthermore, we identify areas for future research regarding the management of large vessel giant cell arteritis.

Vascular disease persistence in giant cell arteritis: are stromal cells neglected?

Giant cell arteritis (GCA), the most common systemic vasculitis, is characterised by aberrant interactions between infiltrating and resident cells of the vessel wall. Ageing and breach of tolerance are prerequisites for GCA development, resulting in dendritic and T-cell dysfunction. Inflammatory cytokines polarise T-cells, activate resident macrophages and synergistically enhance vascular inflammation, providing a loop of autoreactivity. These events originate in the adventitia, commonly regarded as the biological epicentre of the vessel wall, with additional recruitment of cells that infiltrate and migrate towards the intima. Thus, GCA-vessels exhibit infiltrates across the vascular layers, with various cytokines and growth factors amplifying the pathogenic process. These events activate ineffective repair mechanisms, where dysfunctional vascular smooth muscle cells and fibroblasts phenotypically shift along their lineage and colonise the intima. While high-dose glucocorticoids broadly suppress these inflammatory events, they cause well known deleterious effects. Despite the emerging targeted therapeutics, disease relapse remains common, affecting >50% of patients. This may reflect a discrepancy between systemic and local mediators of inflammation. Indeed, temporal arteries and aortas of GCA-patients can show immune-mediated abnormalities, despite the treatment induced clinical remission. The mechanisms of persistence of vascular disease in GCA remain elusive. Studies in other chronic inflammatory diseases point to the fibroblasts (and their lineage cells including myofibroblasts) as possible orchestrators or even effectors of disease chronicity through interactions with immune cells. Here, we critically review the contribution of immune and stromal cells to GCA pathogenesis and analyse the molecular mechanisms by which these would underpin the persistence of vascular disease.

Immune checkpoints in autoimmune vasculitis

Giant cell arteritis (GCA) is a prototypic autoimmune disease with a highly selective tissue tropism for medium and large arteries. Extravascular GCA manifests with intense systemic inflammation and polymyalgia rheumatica; vascular GCA results in vessel wall damage and stenosis, causing tissue ischemia. Typical granulomatous infiltrates in affected arteries are composed of CD4+ T cells and hyperactivated macrophages, signifying the involvement of the innate and adaptive immune system. Lesional CD4+ T cells undergo antigen-dependent clonal expansion, but antigen-nonspecific pathways ultimately control the intensity and duration of pathogenic immunity. Patient-derived CD4+ T cells receive strong co-stimulatory signals through the NOTCH1 receptor and the CD28/CD80-CD86 pathway. In parallel, co-inhibitory signals, designed to dampen overshooting T cell immunity, are defective, leaving CD4+ T cells unopposed and capable of supporting long-lasting and inappropriate immune responses. Based on recent data, two inhibitory checkpoints are defective in GCA: the Programmed death-1 (PD-1)/Programmed cell death ligand 1 (PD-L1) checkpoint and the CD96/CD155 checkpoint, giving rise to the "lost inhibition concept". Subcellular and molecular analysis has demonstrated trapping of the checkpoint ligands in the endoplasmic reticulum, creating PD-L1low CD155low antigen-presenting cells. Uninhibited CD4+ T cells expand, release copious amounts of the cytokine Interleukin (IL)-9, and differentiate into long-lived effector memory cells. These data place GCA and cancer on opposite ends of the co-inhibition spectrum, with cancer patients developing immune paralysis due to excessive inhibitory checkpoints and GCA patients developing autoimmunity due to nonfunctional inhibitory checkpoints.

[18F]FDG PET/CT for therapeutic assessment of Abatacept in early-onset polymyalgia rheumatica

PURPOSE

Evaluate the benefit of 2-deoxy-2-[18F]-fluoro-D-glucose ([18F] FDG) positron emission tomography/computed tomography (PET/CT) for the therapeutic assessment of Abatacept (ABA) as first-line therapy in early-onset polymyalgia rheumatica (PMR) patients.

METHODS

This was an ancillary study of ALORS trial (Abatacept in earLy Onset polymyalgia Rheumatica Study) assessing the ability of ABA versus placebo to achieve low disease activity (C-Reactive Protein PMR activity score (CRP PMR-AS) ≤ to 10) without glucocorticoid (GC) at week 12 in patients with early-onset PMR. The patients underwent [18F] FDG PET/CT at baseline and after 12 weeks of treatment. Responses to treatments were evaluated according to CRP PMR-AS, Erythrocyte Sedimentation Rate (ESR) PMR-AS, Clin PMR-AS, and CRP-Imputed (Imput-CRP) PMR-AS. Quantitative score by maximal standardized uptake value (SUVmax) and combined qualitative scores according to liver uptake (Leuven, Leuven/Groningen, and Besançon Scores) were used for assessment of [18F] FDG uptake in regions of interest (ROI) usually affected in PMR. Student's t-test was applied to evaluate the clinical, biological, and [18F] FDG uptake variation difference in ABA and placebo groups between W0 and W12. Subgroup analysis by GC rescue was performed.

RESULTS

At W12, there was no significant difference according to SUVmax between the ABA and the placebo groups in all ROI. Subgroup analysis according to GC administration demonstrated a significant (p 0.047) decrease in SUVmax within the left sternoclavicular joint ROI in the ABA group (- 0.8) compared to the placebo group (+ 0.6) without GC rescue. Other results did not reveal any significant difference between the ABA and placebo groups. According to combined qualitative scores, there was no significant difference between ABA and placebo groups for the direct comparison analysis and subgroup analysis according to GC rescue.

CONCLUSION

[18F] FDG PET/CT uptake did not decrease significantly after ABA compared to placebo in anatomical areas usually affected in PMR patients. These results are correlated with the clinical-biological therapeutic assessment.

CLINICAL TRIAL REGISTRATION

The study was approved by the appropriate ethics committee (CPP Sud-Est II Ref CPP: 2018-33), and all patients gave their written informed consent before study enrollment. The protocol was registered on Clinicaltrials.gov (NCT03632187).

Establishing clinical remission criteria for giant cell arteritis: Results of a Delphi exercise carried out by an expert panel of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis

OBJECTIVE

To develop a proposal for giant cell arteritis remission criteria in order to implement a treat-to-target algorithm.

METHODS

A task force consisting of 10 rheumatologists, 3 cardiologists, 1 nephrologist, and 1 cardiac surgeon was established in the Large-vessel Vasculitis Group of the Japanese Research Committee of the Ministry of Health, Labour and Welfare for Intractable Vasculitis to conduct a Delphi survey of remission criteria for giant cell arteritis. The survey was circulated among the members over four reiterations with four face-to-face meetings. Items with a mean score of ≥4 were extracted as items for defining remission criteria.

RESULTS

An initial literature review yielded a total of 117 candidate items for disease activity domains and treatment/comorbidity domains of remission criteria, of which 35 were extracted as disease activity domains (systematic symptoms, signs and symptoms of cranial and large-vessel area, inflammatory markers, and imaging findings). For the treatment/comorbidity domain, ≤5 mg/day of prednisolone 1 year after starting glucocorticoids was extracted. The definition of achievement of remission was the disappearance of active disease in the disease activity domain, normalization of inflammatory markers, and ≤5 mg/day of prednisolone.

CONCLUSION

We developed proposals for remission criteria to guide the implementation of a treat-to-target algorithm for giant cell arteritis.

Review of phase 2/3 trials in polymyalgia rheumatica and giant cell arteritis

INTRODUCTION

GCA (giant cell arteritis) and PMR (polymyalgia rheumatica) are two overlapping inflammatory rheumatic conditions that are seen exclusively in older adults, sharing some common features. GCA is a clinical syndrome characterized by inflammation of the medium and large arteries, with both cranial and extracranial symptoms. PMR is a clinical syndrome characterized by stiffness in the neck, shoulder, and pelvic girdle muscles. Both are associated with constitutional symptoms.

AREAS COVERED

In this review, we assess the established and upcoming treatments for GCA and PMR. We review the current treatment landscape, completed trials, and upcoming trials in these conditions, to identify new and promising therapies.

EXPERT OPINION

Early use of glucocorticoids (GC) remains integral to the immediate management of PMR and GCA but being aware of patient co-morbidities that may influence treatment toxicity is paramount. As such GC sparing agents are required in the treatment of PMR. Currently there are limited treatment options available for PMR and GCA, and significant unmet needs remain. Newer mechanisms of action, and hence therapeutic options being studied include CD4 T cell co-stimulation blockade, IL-17 inhibition, IL-12/23 inhibition, GM-CSF inhibition, IL-1β inhibition, TNF-α antagonist and Jak inhibition, among others, which will be discussed in this review.

Effect of combined treatment with prednisone and methotrexate versus prednisone alone over laboratory parameters in giant cell arteritis

OBJECTIVE

To compare the effect of combined treatment with prednisone and methotrexate (MTX) versus prednisone alone over laboratory parameters in giant cell arteritis (GCA).

PATIENTS AND METHODS

We performed a double-blind, placebo-controlled, randomized clinical trial about usefulness of treatment with prednisone and MTX versus prednisone and placebo in GCA (Ann Intern Med 2001;134:106-114). As a part of follow-up of patients (n=42), we performed laboratory analysis in 20 time points during the two-year period of follow-up. To analyze differences, we calculated the area under the curve (AUC) for erythrocyte sedimentation rate (ESR), hemoglobin, and platelets, and compared the results in both groups adjusting by time of follow-up, existence of relapses and dose of prednisone.

RESULTS

A total of 724 laboratory measurements were done. Median value of ESR was 33 [18-56] in patients with placebo and 26 [15-44] in patients with MTX (P=0.0002). No significant differences were observed in ESR during relapses. The mean ESR value followed a parallel course in both groups, but was lower in the group with MTX than in the group with placebo in 18 of 20 time points of follow-up. The AUC of ESR by time of follow-up was 28,461.7±12,326 in the group with placebo and 19,598.4±8,117 in the group with MTX (mean difference 8,863, 95% CI 1.542-16.184; P=0.019). The course of other laboratory parameters paralleled, without statistical significance, those observed for ESR.

CONCLUSIONS

These data, along with clinical data, suggest that MTX might play a role as a disease-modifying agent in the treatment of GCA.

Evidence on treat to target strategies in polymyalgia rheumatica and giant cell arteritis: a systematic literature review

OBJECTIVES

To inform an international task force about current evidence on Treat to Target (T2T) strategies in PMR and GCA.

METHODS

A systematic literature research (SLR) was conducted in Medline, EMBASE, Cochrane Library, clinicaltrials.gov from their inception date to May 2022, and in the EULAR/ACR abstract database (2019-2021). Randomised clinical trials (RCTs) and non-randomised interventional studies published in English and answering at least one of the eleven PICO questions on T2T strategies, treatment targets and outcomes, framed by the taskforce, were identified. Study selection process, data extraction and risk of bias assessment were conducted independently by two investigators.

RESULTS

Of 7809 screened abstracts, 397 were selected for detailed review and 76 manuscripts were finally included (31 RCTs, eight subgroup/exploratory analyses of RCTs and 37 non-randomised interventional studies). No study comparing a T2T strategy against standard of care was identified. In PMR RCTs, the most frequently applied outcomes concerned treatment (90.9% of RCTs), particularly the cumulative glucocorticoids (GC) dose and GC tapering, followed by clinical, laboratory and safety outcomes (63.3% each). Conversely, the most commonly reported outcomes in RCTs in GCA were prevention of relapses (72.2%), remission as well as treatment-related and safety outcomes (67.0% each).

CONCLUSIONS

This SLR provides evidence and highlights the knowledge gaps on T2T strategies in PMR and GCA, informing the task force developing T2T recommendations for these diseases.

New Therapeutic Approaches to Large-Vessel Vasculitis

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are large-vessel vasculitides affecting the aorta and its branches. Arterial damage from these diseases may result in ischemic complications, aneurysms, and dissections. Despite their similarities, the management of GCA and TAK differs. Glucocorticoids are used frequently but relapses are common, and glucocorticoid toxicity contributes to significant morbidity. Conventional immunosuppressive therapies can be beneficial in TAK, though their role in the management of GCA remains unclear. Tumor necrosis factor inhibitors improve remission rates and appear to limit vascular damage in TAK; these agents are not beneficial in GCA. Tocilizumab is the first biologic glucocorticoid-sparing agent approved for use in GCA and also appears to be effective in TAK. A better understanding of the pathogenesis of both conditions and the availability of targeted therapies hold much promise for future management.

Treatment for giant cell arteritis with 8 weeks of prednisone in combination with tocilizumab: a single-arm, open-label, proof-of-concept study

BACKGROUND

Even after the approval of tocilizumab, substantial glucocorticoid exposure (usually ≥6 months) and toxicity continue to be important problems for patients with giant cell arteritis. We aimed to assess the outcomes of a group of patients with giant cell arteritis treated with tocilizumab in combination with 8 weeks of prednisone.

METHODS

This prospective, single arm, proof-of-concept study was conducted at Massachusetts General Hospital (Boston, MA, USA). Individuals aged 50 years or older who had new-onset or relapsing giant cell arteritis with active disease were eligible for inclusion. Participants received 12 months of tocilizumab 162 mg weekly subcutaneously in combination with 8 weeks of prednisone. The primary endpoint was sustained prednisone-free remission at week 52. Adverse events were also evaluated. This trial is registered with ClinicalTrials.gov (NCT03726749), and is complete.

FINDINGS

Between Nov 28, 2018, and Nov 2, 2020, we enrolled 30 patients (mean age 73·7 years [SD 8·1], 18 [60%] women and 12 [40%] men, 30 [100%] White race, 15 [50%] new-onset disease, 23 [77%] temporal artery biopsy-proven, 14 [47%] imaging-proven). The initial prednisone doses were 60 mg (n=7), 50 mg (n=1), 40 mg (n=7), 30 mg (n=6), and 20 mg (n=9). All patients entered remission within 4 weeks from baseline. 23 (77%) of 30 patients were in sustained prednisone-free remission at week 52 and seven (23%) patients relapsed, with a mean time to relapse of 15·8 weeks (SD 14·7). Overall, four (13%) participants developed a serious adverse event, including one related or probably related to prednisone exclusively, two related or probably related to tocilizumab exclusively, and one related or probably related to prednisone, tocilizumab, or both. Two of the non-responder patients stopped tocilizumab and withdrew from the study prematurely after having a second disease relapse. No cases of giant cell arteritis-related permanent vision loss occurred during the study.

INTERPRETATION

These results suggest that 12 months of tocilizumab in combination with 8 weeks of prednisone could induce and maintain remission in patients with giant cell arteritis. Confirmation of these findings in a randomised controlled trial is required.

FUNDING

Genentech.

Advances and challenges in management of large vessel vasculitis

Glucocorticoids (GC) remains the mainstay for management of large vessel vasculitis (LVV). Recent introduction of interleukin-6 signaling blocker, tocilizumab has substantially changed the practice in management of patients with LVV, in particular, giant cell arteritis (GCA). Benefit of tocilizumab to patients with Takayasu arteritis (TAK) is supported by observational studies, but randomized clinical trials are lacking. Addition of tocilizumab enables reduction of the total amount of GC in patients with GCA, but GC burden remains high and to be further reduced. Ongoing studies aim at minimal use of GC or even GC-free. Tumor necrosis factor inhibitors appear to be beneficial to TAK despite their ineffectiveness to GCA. Randomized clinical trials are undergoing to target other inflammatory cytokines in both GCA and TAK. Janus kinase inhibitors alone or in combination with conventional disease modifying anti-rheumatic drugs showed promising results in treatment of TAK.

Abatacept in early polymyalgia rheumatica (ALORS): a proof-of-concept, randomised, placebo-controlled, parallel-group trial

BACKGROUND

Medium-dose glucocorticoids can improve symptoms in nearly all patients with polymyalgia rheumatica. According to its good safety profile, abatacept could be used instead of glucocorticoids in early polymyalgia rheumatica. We aimed to determine whether the efficacy of abatacept is sufficient to justify larger studies in early polymyalgia rheumatica.

METHODS

To evaluate whether abatacept allows low disease activity without glucocorticoids in early polymyalgia rheumatica, we conducted a proof-of-concept, randomised, double-blind, placebo-controlled, parallel-group trial. Participants were recruited from five centres in France (in Brest, Le Mans, Morlaix, Dinan and Saint Malo, and Strasbourg) and were included if they had recent-onset (<6 months) polymyalgia rheumatica with a C-reactive protein (CRP) polymyalgia rheumatica activity score (PMR-AS) of more than 17 without any signs or symptoms of giant cell arteritis (clinical and [18F]fluorodeoxyglucose PET-CT evaluation). Participants were randomly assigned (1:1) to receive weekly subcutaneous abatacept (125 mg) or matching placebo, with glucocorticoid rescue therapy allowed in cases of high disease activity, for 12 weeks, and then glucocorticoid treatment based on disease activity, until week 36. Investigators, patients, outcome assessors, and sponsor personnel were masked to group assignments. The primary endpoint was low disease activity (CRP PMR-AS ≤10) at week 12 without glucocorticoids and without rescue treatment. The study was powered to demonstrate a 60% difference in response rates between groups. Open-ended adverse events were collected at each visit by clinicians and were categorised following system organ class classification after study completion. The ALORS trial is registered with ClinicalTrials.gov, NCT03632187.

FINDINGS

34 patients (22 women and 12 men) were randomly assigned between Dec 13, 2018, and Oct 21, 2021. All patients who had been randomly assigned were included in the analysis. The primary endpoint was reached by eight (50%) of 16 patients in the abatacept group and four (22%) of 18 patients in the placebo group (relative risk 2·2 [0·9-5·5]); crude p=0·15; adjusted p=0·070). Eight (50%) patients in the abatacept and 15 (83%) in the placebo group had adverse events. Four patients (one [6%] in the abatacept group and three [17%] in the placebo group) had serious adverse events. There were no deaths or new safety concerns.

INTERPRETATION

This study suggests that the effect of abatacept alone is not strong enough to justify larger studies in early polymyalgia rheumatica. This is only a first step in deciding whether a larger study should be conducted in early polymyalgia rheumatica and does not exclude a potential effect of abatacept in glucocorticoid-dependent polymyalgia rheumatica.

FUNDING

BMS Pharma France.

Rheumatic complications of checkpoint inhibitors: Lessons from autoimmunity

Immune checkpoint inhibitors are now an established treatment in the management of a range of cancers. Their success means that their use is likely to increase in future in terms of the numbers of patients treated, the indications and the range of immune checkpoints targeted. They function by counteracting immune evasion by the tumor but, as a consequence, can breach self-tolerance at other sites leading to a range of immune-related adverse events. Included among these complications are a range of rheumatologic complications, including inflammatory arthritis and keratoconjunctivitis sicca. These superficially resemble immune-mediated rheumatic diseases (IMRDs) such as rheumatoid arthritis and Sjogren's disease but preliminary studies suggest they are clinically and immunologically distinct entities. However, there appear to be common processes that predispose to the development of both that may inform preventative interventions and predictive tools. Both groups of conditions highlight the centrality of immune checkpoints in controlling tolerance and how it can be restored. Here we will discuss some of these commonalities and differences between rheumatic irAEs and IMRDs.

Persistent aortic inflammation in patients with giant cell arteritis

OBJECTIVES

To investigate the clinicopathologic features of patients with giant cell arteritis (GCA) who had thoracic aorta aneurysm or dissection surgery.

METHODS

Patients who had thoracic aorta surgery between January 1, 2000, and December 31, 2021, at the Mayo Clinic, Rochester, Minnesota, were identified with current procedural terminology (CPT) codes. The identified patients were screened for a prior diagnosis of GCA with diagnostic codes and electronic text search. The available medical records of all the patients of interest were manually reviewed. Thoracic aorta tissues obtained during surgery were re-evaluated in detail by pathologists. The clinicopathologic features of these patients were analyzed. Overall observed survival was compared with lifetable rates from the United States population.

RESULTS

Of the 4621 patients with a CPT code for thoracic aorta surgery, 49 had a previous diagnosis of GCA. Histopathologic evaluation of the aortic tissue revealed active aortitis in most patients with GCA (40/49, 82%) after a median (IQR) of 6.0 (2.6-10.3) years from GCA diagnosis. All patients were considered in clinical remission at the time of aortic surgery. The overall mortality compared to age and sex-matched general population was significantly increased with a standardized mortality ratio of 1.55 (95% CI, 1.05-2.19).

CONCLUSION

Histopathologic evaluation of the thoracic aorta obtained during surgery revealed active aortitis in most patients with GCA despite being considered in clinical remission several years after GCA diagnosis. Chronic, smoldering aortic inflammation likely contributes to the development of aortic aneurysm and dissection in GCA.

CTLA-4 Pathway Is Instrumental in Giant Cell Arteritis

BACKGROUND

Giant cell arteritis (GCA) causes severe inflammation of the aorta and its branches and is characterized by intense effector T-cell infiltration. The roles that immune checkpoints play in the pathogenesis of GCA are still unclear. Our aim was to study the immune checkpoint interplay in GCA.

METHODS

First, we used VigiBase, the World Health Organization international pharmacovigilance database, to evaluate the relationship between GCA occurrence and immune checkpoint inhibitors treatments. We then further dissected the role of immune checkpoint inhibitors in the pathogenesis of GCA, using immunohistochemistry, immunofluorescence, transcriptomics, and flow cytometry on peripheral blood mononuclear cells and aortic tissues of GCA patients and appropriated controls.

RESULTS

Using VigiBase, we identified GCA as a significant immune-related adverse event associated with anti-CTLA-4 (cytotoxic T-lymphocyte-associated protein-4) but not anti-PD-1 (anti-programmed death-1) nor anti-PD-L1 (anti-programmed death-ligand 1) treatment. We further dissected a critical role for the CTLA-4 pathway in GCA by identification of the dysregulation of CTLA-4-derived gene pathways and proteins in CD4+ (cluster of differentiation 4) T cells (and specifically regulatory T cells) present in blood and aorta of GCA patients versus controls. While regulatory T cells were less abundant and activated/suppressive in blood and aorta of GCA versus controls, they still specifically upregulated CTLA-4. Activated and proliferating CTLA-4+ Ki-67+ regulatory T cells from GCA were more sensitive to anti-CTLA-4 (ipilimumab)-mediated in vitro depletion versus controls.

CONCLUSIONS

We highlighted the instrumental role of CTLA-4 immune checkpoint in GCA, which provides a strong rationale for targeting this pathway.

Giant Cell Arteritis and Polymyalgia Rheumatica: Treatment Approaches and New Targets

Prolonged glucocorticoid tapers have been the standard of care for giant cell arteritis (GCA) and polymyalgia rheumatica (PMR), but recent advancements have improved outcomes for patients with GCA while reducing glucocorticoid-related toxicities. Many patients with GCA and PMR still experience persistent or relapsing disease, and cumulative exposure to glucocorticoids for both diseases remains high. The objective of this review is to define current treatment approaches as well as new therapeutic targets and strategies. Studies investigating inhibition of cytokine pathways, including interleukin-6, interleukin-17, interleukin-23, granulocyte-macrophage colony-stimulating factor, Janus kinase-signal transduction and activator of transcription, and others, will be reviewed.

Disease stratification in GCA and PMR: state of the art and future perspectives

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are closely related conditions characterized by systemic inflammation, a predominant IL-6 signature, an excellent response to glucocorticoids, a tendency to a chronic and relapsing course, and older age of the affected population. This Review highlights the emerging view that these diseases should be approached as linked conditions, unified under the term GCA-PMR spectrum disease (GPSD). In addition, GCA and PMR should be seen as non-monolithic conditions, with different risks of developing acute ischaemic complications and chronic vascular and tissue damage, different responses to available therapies and disparate relapse rates. A comprehensive stratification strategy for GPSD, guided by clinical findings, imaging and laboratory data, facilitates appropriate therapy and cost-effective use of health-economic resources. Patients presenting with predominant cranial symptoms and vascular involvement, who usually have a borderline elevation of inflammatory markers, are at an increased risk of sight loss in early disease but have fewer relapses in the long term, whereas the opposite is observed in patients with predominant large-vessel vasculitis. How the involvement of peripheral joint structures affects disease outcomes remains uncertain and understudied. In the future, all cases of new-onset GPSD should undergo early disease stratification, with their management adapted accordingly.

Biologic therapy in large and small vessels vasculitis, and Behçet's disease: Evidence- and practice-based guidance

OBJECTIVE

Vasculitis are a very heterogenous group of systemic autoimmune diseases, affecting large vessels (LVV), small vessels or presenting as a multisystemic variable vessel vasculitis. We aimed to define evidence and practice-based recommendations for the use of biologics in large and small vessels vasculitis, and Behçet's disease (BD).

METHODS

Recommendations were made by an independent expert panel, following a comprehensive literature review and two consensus rounds. The panel included 17 internal medicine experts with recognized practice on autoimmune diseases management. The literature review was systematic from 2014 until 2019 and later updated by cross-reference checking and experts' input until 2022. Preliminary recommendations were drafted by working groups for each disease and voted in two rounds, in June and September 2021. Recommendations with at least 75% agreement were approved.

RESULTS

A total of 32 final recommendations (10 for LVV treatment, 7 for small vessels vasculitis and 15 for BD) were approved by the experts and several biologic drugs were considered with different supporting evidence. Among LVV treatment options, tocilizumab presents the higher level of supporting evidence. Rituximab is recommended for treatment of severe/refractory cryoglobulinemic vasculitis. Infliximab and adalimumab are most recommended in treatment of severe/refractory BD manifestations. Other biologic drugs can be considered is specific presentations.

CONCLUSION

These evidence and practice-based recommendations are a contribute to treatment decision and may, ultimately, improve the outcome of patients living with these conditions.

Tocilizumab in giant cell arteritis: an update for the clinician

PURPOSE OF REVIEW

The recent approval of tocilizumab (TCZ) for the treatment of giant cell arteritis (GCA) has changed the landscape for management of this disease. Herein, we review recent literature addressing practical questions for the clinician regarding the use of TCZ in GCA. We evaluate efficacy of TCZ across different disease phenotypes, optimal dosing and formulation, treatment-related toxicity, recommendations for monitoring disease, and duration of therapy.

RECENT FINDINGS

Post-hoc analyses of a large clinical trial and real-world data suggest efficacy of TCZ across various disease phenotypes in GCA, and support use of weekly subcutaneous dosing over every-other-week dosing. More data are needed to guide duration of TCZ therapy, optimal disease activity monitoring in patients treated with TCZ, and to speak to efficacy in GCA with large vessel involvement.

SUMMARY

TCZ has added valuably to the treatment arsenal in GCA, though more data are needed to guide optimal use of the drug.

Outcomes during and after long-term tocilizumab treatment in patients with giant cell arteritis

OBJECTIVE

To assess outcomes in giant cell arteritis (GCA) patients during and after long-term tocilizumab (TCZ) treatment.

METHODS

Retrospective analysis of GCA patients treated with TCZ at a single centre (2010-2022). Time to relapse and annualised relapse rate during and after TCZ treatment, prednisone use, and safety were assessed. Relapse was defined as reappearance of any GCA clinical manifestation that required treatment intensification, regardless of C reactive protein levels and erythrocyte sedimentation rate.

RESULTS

Sixty-five GCA patients were followed for a mean (SD) of 3.1 (1.6) years. The mean duration of the initial TCZ course was 1.9 (1.1) years. The Kaplan-Meier (KM)-estimated relapse rate at 18 months on TCZ was 15.5%. The first TCZ course was discontinued due to satisfactory remission achievement in 45 (69.2%) patients and adverse events in 6 (9.2%) patients. KM-estimated relapse rate at 18 months after TCZ discontinuation was 47.3%. Compared with patients stopping TCZ at or before 12 months of treatment, the multivariable adjusted HR (95% CI) for relapse in patients on TCZ beyond 12 months was 0.01 (0.00 to 0.28; p=0.005). Thirteen patients received >1 TCZ course. Multivariable adjusted annualised relapse rates (95% CI) in all periods on and off TCZ aggregated were 0.1 (0.1 to 0.2) and 0.4 (0.3 to 0.7), respectively (p=0.0004). Prednisone was discontinued in 76.9% of patients. During the study, 13 serious adverse events occurred in 11 (16.9%) patients.

CONCLUSION

Long-term TCZ treatment was associated with remission maintenance in most patients with GCA. The estimated relapse rate by 18 months after TCZ discontinuation was 47.3%.

The provisional OMERACT ultrasonography score for giant cell arteritis

OBJECTIVES

To develop an Outcome Measures in Rheumatology (OMERACT) ultrasonography score for monitoring disease activity in giant cell arteritis (GCA) and evaluate its metric properties.

METHODS

The OMERACT Instrument Selection Algorithm was followed. Forty-nine members of the OMERACT ultrasonography large vessel vasculitis working group were invited to seven Delphi rounds. An online reliability exercise was conducted using images of bilateral common temporal arteries, parietal and frontal branches as well as axillary arteries from 16 patients with GCA and 7 controls. Sensitivity to change and convergent construct validity were tested using data from a prospective cohort of patients with new GCA in which ultrasound-based intima-media thickness (IMT) measurements were conducted at weeks 1, 3, 6, 12 and 24.

RESULTS

Agreement was obtained (92.7%) for the OMERACT GCA Ultrasonography Score (OGUS), calculated as follows: sum of IMT measured in every segment divided by the rounded cut-off values of IMTs in each segment. The resulting value is then divided by the number of segments available. Thirty-five members conducted the reliability exercise, the interrater intraclass correlation coefficient (ICC) for the OGUS was 0.72-0.84 and the median intrareader ICC was 0.91. The prospective cohort consisted of 52 patients. Sensitivity to change between baseline and each follow-up visit up to week 24 yielded standardised mean differences from -1.19 to -2.16, corresponding to large and very large magnitudes of change, respectively. OGUS correlated moderately with erythrocyte sedimentation rate, C reactive protein and Birmingham Vasculitis Activity Score (corrcoeff 0.37-0.48).

CONCLUSION

We developed a provisional OGUS for potential use in clinical trials.

Unmet need in the treatment of polymyalgia rheumatica and giant cell arteritis

For decades, aside from prednisone and the occasional use of immune suppressive drugs such as methotrexate, there was little to offer patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA). However, there is a great interest in various steroid sparing treatments in both these conditions. This paper aims to provide an overview of our current knowledge of PMR and GCA, examining their similarities and distinctions in terms of clinical presentation, diagnosis, and treatment, with emphasis placed on reviewing recent and ongoing research efforts on emerging treatment. Multiple recent and ongoing clinical trials are demonstrating new therapeutics that will provide benefit and contribute to the evolution of clinical guidelines and standard of care for patients with GCA and/or PMR.

Recent advances in the treatment of giant cell arteritis

Giant cell arteritis (GCA) is a systemic, granulomatous, large-vessel vasculitis that affects individuals over the age of 50 years. Morbidity from disease includes cranial manifestations which can cause irreversible blindness, while extra-cranial manifestations can cause vascular damage with large-artery stenosis, occlusions, aortitis, aneurysms, and dissections. Glucocorticoids while efficacious are associated with significant adverse effects. Furthermore, despite treatment with glucocorticoids, relapses are common. An understanding of the pathogenesis of GCA has led to the discovery of tocilizumab as an efficacious steroid-sparing therapy while additional therapeutic targets affecting different inflammatory pathways are under investigation. Surgical treatment may be indicated in cases of refractory ischemia or aortic complications but data on surgical outcomes are limited. Despite the recent advances, many unmet needs exist, including the identification of patients or subsets of GCA who would benefit from earlier initiation of adjunctive therapies, patients who may warrant long-term immunosuppression and medications that sustain permanent remission. The impact of medications like tocilizumab on long-term outcomes, including the development of aortic aneurysms and vascular damage also warrants investigation.

The role of autoimmunity and autoinflammation in giant cell arteritis: A systematic literature review

Giant cell arteritis is the most common form of large vessel vasculitis and preferentially involves large and medium-sized arteries in patients over the age of 50. Aggressive wall inflammation, neoangiogenesis and consecutive remodeling processes are the hallmark of the disease. Though etiology is unknown, cellular and humoral immunopathological processes are well understood. Matrix metalloproteinase-9 mediated tissue infiltration occurs through lysis of basal membranes in adventitial vessels. CD4+ cells attain residency in immunoprotected niches, differentiate into vasculitogenic effector cells and enforce further leukotaxis. Signaling pathways involve the NOTCH1-Jagged1 pathway opening vessel infiltration, CD28 mediated T-cell overstimulation, lost PD-1/PD-L1 co-inhibition and JAK/STAT signaling in interferon dependent responses. From a humoral perspective, IL-6 represents a classical cytokine and potential Th-cell differentiator whereas interferon-γ (IFN- γ) has been shown to induce chemokine ligands. Current therapies involve glucocorticoids, tocilizumab and methotrexate application. However, new agents, most notably JAK/STAT inhibitors, PD-1 agonists and MMP-9 blocking substances, are being evaluated in ongoing clinical trials.

What is a response in randomised controlled trials in giant cell arteritis?

Glucocorticoids (GCs) are the gold standard for treatment of giant cell arteritis (GCA); however, there is a need for studies on GC-sparing agents, given that up to 85% of patients receiving GC only develop adverse events. Previous randomised controlled trials (RCTs) have applied different primary endpoints, limiting the comparison of treatment effects in meta-analyses and creating an undesired heterogeneity of outcomes. The harmonisation of response assessment is therefore an important unmet need in GCA research. In this viewpoint article, we discuss the challenges and opportunities with the development of new, internationally accepted response criteria. A change of disease activity is a fundamental component of response; however, it is debatable whether the ability to taper GC and/or the maintenance of a disease state for a specific time period, as applied in recent RCTs, should be part of response assessment. The role of imaging and novel laboratory biomarkers as possible objective markers of disease activity needs further investigation but might be a possibility when drugs directly or indirectly influence the levels of traditional acute-phase reactants such as erythrocyte sedimentation rate and C reactive protein. Futures response criteria might be constructed as a multidomain set, but the questions about which domains will be included and what their relative weights will be still need to be answered.

Management of ocular arterial ischemic diseases: a review

PURPOSE

To summarize the existing treatment options regarding central retinal artery occlusion (CRAO), branch retinal artery occlusion (BRAO), arteritic anterior ischemic optic neuropathy (AAION), non-arteritic anterior ischemic optic neuropathy (NAION), and ocular ischemic syndrome (OIS), proposing an approach to manage and treat these patients.

METHODS

A systematic literature search of articles published since 1st January 2010 until 31st December 2020 was conducted using MEDLINE (PubMed), Scopus, and Web of Science. Exclusion criteria included case reports, non-English references, articles not conducted in humans, and articles not including diagnostic or therapeutic options. Further references were gathered through citation tracking, by hand search of the reference lists of included studies, as well as topic-related European society guidelines.

RESULTS

Acute ocular ischemia, with consequent visual loss, has a variety of causes and clinical presentations, with prognosis depending on an accurate diagnosis and timely therapeutic implementation. Unfortunately, most of the addressed entities do not have a standardized management, especially regarding their treatment, which often lacks good quality evidence on whether it should or not be used to treat patients.

CONCLUSION

Ophthalmologic signs and symptoms may be a warning sign of cardiovascular or cerebrovascular events, namely stroke. Most causes of acute ocular ischemia do not have a standardized management, especially regarding their treatment. Timely intervention is essential to improve the visual, and possibly vital, prognosis. Awareness must be raised among non-ophthalmologist clinicians that might encounter these patients. Further research should focus on assessing the benefit of the management strategies already being employed .

Human monocyte-derived suppressive cells (HuMoSC) for cell therapy in giant cell arteritis

Introduction

The pathogenesis of Giant Cell Arteritis (GCA) relies on vascular inflammation and vascular remodeling, the latter being poorly controlled by current treatments.

Methods

This study aimed to evaluate the effect of a novel cell therapy, Human Monocyte-derived Suppressor Cells (HuMoSC), on inflammation and vascular remodeling to improve GCA treatment. Fragments of temporal arteries (TAs) from GCA patients were cultured alone or in the presence of HuMoSCs or their supernatant. After five days, mRNA expression was measured in the TAs and proteins were measured in culture supernatant. The proliferation and migration capacity of vascular smooth muscle cells (VSMCs) were also analyzed with or without HuMoSC supernatant.

Results

Transcripts of genes implicated in vascular inflammation (CCL2, CCR2, CXCR3, HLADR), vascular remodeling (PDGF, PDGFR), angiogenesis (VEGF) and extracellular matrix composition (COL1A1, COL3A1 and FN1) were decreased in arteries treated with HuMoSCs or their supernatant. Likewise, concentrations of collagen-1 and VEGF were lower in the supernatants of TAs cultivated with HuMoSCs. In the presence of PDGF, the proliferation and migration of VSMCs were both decreased after treatment with HuMoSC supernatant. Study of the PDGF pathway suggests that HuMoSCs act through inhibition of mTOR activity. Finally, we show that HuMoSCs could be recruited in the arterial wall through the implication of CCR5 and its ligands.

Conclusion

Altogether, our results suggest that HuMoSCs or their supernatant could be useful to decrease vascular in flammation and remodeling in GCA, the latter being an unmet need in GCA treatment.

Giant cell arteritis: Update on clinical manifestations, diagnosis, and management

Giant cell arteritis (GCA) is the most common vasculitis affecting people older than 50 years. The last decades have shed new light on the clinical paradigm of this condition, expanding its spectrum beyond cranial vessel inflammation. GCA can be now considered a multifaceted vasculitic syndrome encompassing inflammation of cranial and extra-cranial arteries and girdles, isolated or combined. Such heterogeneity often leads to diagnostic delays and increases the likelihood of acute and chronic GCA-related damage. On the other hand, the approach to suspected GCA patients has been revolutionized by the introduction of vascular ultrasound which allows a rapid, cost-effective, and non-invasive GCA diagnosis. Likewise, the use of tocilizumab is now part of the therapeutic algorithm of GCA and ensures a satisfactory disease control even in steroid-refractory patients. Nonetheless, some aspects of GCA still need to be clarified, including the clinical correlation of different histological patterns, and the prevention of long-term vascular complications. This narrative review depicts the diagnostic and therapeutic aspects of GCA most relevant in clinical practice, with a focus on clinical updates and novelties introduced over the last decade.

Current developments in the diagnosis and treatment of giant cell arteritis

Giant cell arteritis is the most common vasculitis in adults above 50 years old. The disease is characterized by granulomatous inflammation of medium and large arteries, particularly the temporal artery, and is associated acutely with headache, claudication, and visual disturbances. Diagnosis of the disease is often complicated by its protean presentation and lack of consistently reliable testing. The utility of color doppler ultrasound at the point-of-care and FDG-PET in longitudinal evaluation remain under continued investigation. Novel techniques for risk assessment with Halo scoring and stratification through axillary vessel ultrasound are becoming commonplace. Moreover, the recent introduction of the biologic tocilizumab marks a paradigm shift toward using glucocorticoid-sparing strategies as the primary treatment modality. Notwithstanding these developments, patients continue to have substantial rates of relapse and biologic agents have their own side effect profile. Trials are underway to answer questions about optimal diagnostic modality, regiment choice, and duration.

Pan American League of Associations for Rheumatology guidelines for the treatment of giant cell arteritis

Considerable variability exists in the way that health-care providers treat patients with giant cell arteritis in Latin America, with patients commonly exposed to excessive amounts of glucocorticoids. In addition, large health disparities prevail in this region due to socioeconomic factors, which influence access to care, including biological treatments. For these reasons, the Pan American League of Associations for Rheumatology developed the first evidence-based giant cell arteritis treatment guidelines tailored for Latin America. A panel of vasculitis experts from Mexico, Colombia, Peru, Brazil, and Argentina generated clinically meaningful questions related to the treatment of giant cell arteritis in the population, intervention, comparator, and outcome (PICO) format. Following the grading of recommendations, assessment, development, and evaluation methodology, a team of methodologists did a systematic literature search, extracted and summarised the effects of the interventions, and graded the quality of the evidence. The panel of vasculitis experts voted on each PICO question and made recommendations, which required at least 70% agreement among the voting members to be included in the guidelines. Nine recommendations and one expert opinion statement for the treatment of giant cell arteritis were developed considering the most up-to-date evidence and the socioeconomic characteristics of Latin America. These recommendations include guidance for the use of glucocorticoids, tocilizumab, methotrexate, and aspirin for patients with giant cell arteritis.

Indirect Comparison of Glucocorticoid-Sparing Agents for Remission Maintenance in Giant Cell Arteritis: A Network Meta-analysis

OBJECTIVE

To compare and rank the effect of glucocorticoid-sparing agents in giant cell arteritis (GCA), for which several drugs have been evaluated but with a benefit-risk balance that remains uncertain.

METHODS

The MEDLINE and Clinical Trials databases were searched up to November 2021; all randomized controlled trials investigating glucocorticoids in GCA were included. The glucocorticoid regimen was dichotomized into short (≤6 months) or prolonged (>6 months) use. Risk of relapse and safety were estimated using network meta-analysis with frequentist random effects models.

RESULTS

Of the 96 records screened, 8 trials were included (572 patients). The trials compared glucocorticoids and a sparing agent: tocilizumab (2 trials), oral methotrexate (3 trials), infliximab (1 trial), etanercept (1 trial), and adalimumab (1 trial). The pooled prevalence of GCA relapse was 52.6% (95% CI, 38.1 to 66.9). The risk of relapse was significantly lower with tocilizumab compared with methotrexate (relative risk [RR], 0.41; 95% CI, 0.17 to 0.97) and prolonged (RR, 0.41; 95% CI, 0.20 to 0.83) and short (RR, 0.32; 95% CI, 0.16 to 0.66) glucocorticoid use. The risk of relapse was not significantly different with methotrexate compared with short (RR, 0.79; 95% CI, 0.48 to 1.31) and prolonged (RR, 0.95; 95% CI, 0.31 to 2.89) glucocorticoid use. The frequency of serious adverse events and serious infection was comparable between the different drugs. The certainty of the evidence was low to very low.

CONCLUSION

This meta-analysis suggests that tocilizumab may be superior to other sparing agents to prevent GCA relapse, but with a low to very low certainty of evidence, and that safety is comparable to the other drugs.

REGISTRATION

The protocol of the meta-analysis is registered in the international prospective register of systematic reviews PROSPERO (https://www.crd.york.ac.uk/prospero/; registration CRD42020112387).

Giant Cell Arteritis: Focusing on Current Aspects From the Clinic to Diagnosis and Treatment

Giant cell arteritis (GCA) is a granulomatous arteritis involving large arteries, particularly the aorta and its major proximal branches, including the carotid and temporal arteries. GCA involves individuals over 50 years old. The etiopathogenesis of GCA may involve a genetic background triggered by unknown environmental factors (eg infections), the activation of dendritic cells as well as inflammatory and vascular remodeling. However, its pathogenetic mechanism still remains unclear, although progress has been made in recent years. In the past, inflammatory markers and arterial biopsy were considered as gold standard for the diagnosis of GCA. However, emerging imaging methods have been made more sensitive and specific for the diagnosis of GCA. Treatment includes biological and other modalities including interleukin-6 (IL-6) inhibitors.

The role of PET/CT in large vessel vasculitis and related disorders: diagnosis, extent evaluation and assessment of therapy response

Large vessel vasculitides (LVV) are defined as chronic inflammatory disorders that affect the arteries with two major variants being distinguished: giant cell arteritis (GCA) and Takayasu's arteritis (TAK). These often present with nonspecific constitutional symptoms which makes an accurate diagnosis often challenging. Nevertheless, timely diagnosis is of utmost importance to initiate treatment and to avoid potential life-threatening complications. [¹⁸F]FDG-PET/CT is nowadays widely accepted as useful tool to aid in the diagnosis of large vessel vasculitis. However, its role to monitor disease activity and to predict disease relapse during follow-up is less obvious since vascular [¹⁸F]FDG uptake can be detected in the absence of clinical or biochemical signs of disease activity. In addition to the two major variants, [¹⁸F]FDG-PET/CT has shown promise in (peri-)aortitis and related disorders. This article aims to provide an update on the current knowledge and limitations of [¹⁸F]FDG-PET/CT for the diagnosis and assessment of treatment response in LVV. Furthermore, other radiopharmaceuticals targeting key components of the vascular immune system are being discussed which could provide an interesting alternative to image vascular inflammation in LVV.

Global Transcriptomic Profiling Identifies Differential Gene Expression Signatures Between Inflammatory and Noninflammatory Aortic Aneurysms

OBJECTIVE

To identify hallmark genes and biomolecular processes in aortitis using high-throughput gene expression profiling, and to provide a range of potentially new drug targets (genes) and therapeutics from a pharmacogenomic network analysis.

METHODS

Bulk RNA sequencing was performed on surgically resected ascending aortic tissues from inflammatory aneurysms (giant cell arteritis [GCA] with or without polymyalgia rheumatica, n = 8; clinically isolated aortitis [CIA], n = 17) and noninflammatory aneurysms (n = 25) undergoing surgical aortic repair. Differentially expressed genes (DEGs) between the 2 patient groups were identified while controlling for clinical covariates. A protein-protein interaction model, drug-gene target information, and the DEGs were used to construct a pharmacogenomic network for identifying promising drug targets and potentially new treatment strategies in aortitis.

RESULTS

Overall, tissue gene expression patterns were the most associated with disease state than with any other clinical characteristic. We identified 159 and 93 genes that were significantly up-regulated and down-regulated, respectively, in inflammatory aortic aneurysms compared to noninflammatory aortic aneurysms. We found that the up-regulated genes were enriched in immune-related functions, whereas the down-regulated genes were enriched in neuronal processes. Notably, gene expression profiles of inflammatory aortic aneurysms from patients with GCA were no different than those from patients with CIA. Finally, our pharmacogenomic network analysis identified genes that could potentially be targeted by immunosuppressive drugs currently approved for other inflammatory diseases.

CONCLUSION

We performed the first global transcriptomics analysis in inflammatory aortic aneurysms from surgically resected aortic tissues. We identified signature genes and biomolecular processes, while finding that CIA may be a limited presentation of GCA. Moreover, our computational network analysis revealed potential novel strategies for pharmacologic interventions and suggests future biomarker discovery directions for the precise diagnosis and treatment of aortitis.

Longitudinal monitoring of circulating immune cell phenotypes in large vessel vasculitis

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are two types of primary large vessel vasculitis (LVV). LVV is an intractable, rare disease with a high relapse rate. Disease progression in asymptomatic patients is an important issue in the clinical management of LVV. Useful biomarkers associated with clinical phenotypes, disease activity, and prognosis may be present in peripheral blood. In this review, we focused on peripheral leukocyte counts, surface markers, functions, and gene expression in LVV patients. In particular, we explored longitudinal changes in circulating immune cell phenotypes during the active phase of the disease and during treatment. The numbers and phenotypes of leukocytes in the peripheral blood were different between LVV and healthy controls, GCA and TAK, LVV in active versus treatment phases, and LVV in treatment responders versus non-responders. Therefore, biomarkers obtained from peripheral blood immune cells may be useful for longitudinal monitoring of disease activity in LVV.

Longitudinal Characterization of Vascular Inflammation and Disease Activity in Takayasu Arteritis and Giant Cell Arteritis: A Single-Center Prospective Study

OBJECTIVE

To examine and compare disease activity over time in giant cell arteritis (GCA) and Takayasu arteritis (TAK) using multimodal assessment combining clinical, laboratory, and imaging-based testing.

METHODS

Patients with GCA or TAK were enrolled into a single-center prospective, observational cohort at any point in the disease course. Patients underwent standardized assessment, including ¹⁸ F-fluorodeoxyglucose positron emission tomography (FDG-PET) at enrollment and follow-up visits. Each FDG-PET finding was subjectively interpreted as active or inactive vasculitis. Global arterial FDG uptake was quantified by the PET Vascular Activity Score (PETVAS). Patients were stratified by disease duration at enrollment (0-2 years; 2-5 years; >5 years). Fisher exact and Mann-Whitney U tests, Spearman's correlation, and linear regression were used for statistical analyses.

RESULTS

A total of 126 patients with large vessel vasculitis (GCA = 50; TAK = 76) were evaluated across 319 visits. Clinical disease activity was present in 33% of patients in the second to fifth year of disease and in 24% of patients evaluated >5 years after diagnosis. Active vasculitis by PET was observed in 66% of patients in years 2 to 5 after diagnosis and in 50% of patients enrolled >5 years into disease. PETVASs were consistently higher in GCA than TAK in the early and later phases of disease and significantly decreased over time in GCA but not TAK. Correlations between clinical, laboratory, and imaging findings were complex and varied with disease duration.

CONCLUSION

Disease activity in GCA and TAK is common throughout the disease course. Patterns of vascular PET activity at diagnosis and later in disease differ between GCA and TAK.

Comparing treatment options for large vessel vasculitis

INTRODUCTION

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are the major forms of large vessel vasculitis (LVV).Glucocorticoids represent the cornerstone of LVV treatment, however, relapses and recurrences frequently occur when they are tapered or stopped, determining a prolonged exposure to glucocorticoids and a subsequent increased risk of glucocorticoid-related side effects. Therefore, conventional and biologic immunosuppressive drugs have been proposed to obtain a glucocorticoid-sparing effect.

AREAS COVERED

We searched PubMed® using the keywords "giant cell arteritis/drug therapy" and "Takayasu Arteritis/drug therapy" OR "Takayasu Arteritis/surgery". This review focuses on the management of LVV, based on the current evidence while highlighting the differences in terms of therapeutic management of TAK and GCA.

EXPERT OPINION

Conventional disease modifying anti-rheumatic drugs, such as methotrexate or azathioprine, are recommended in association to glucocorticoids for selected GCA and all TAK patients. Two randomized placebo-controlled trials recently demonstrated the efficacy of tocilizumab in reducing relapses and cumulative prednisone dosage in GCA patients with newly diagnosed or relapsing disease. Observational evidence and two small randomized controlled trials support the use of TNF-alpha inhibitors and tocilizumab as glucocorticoid-sparing agents in relapsing TAK, albeit high-quality evidence regarding the management of TAK is still lacking.

Vasculitogenic T Cells in Large Vessel Vasculitis

Vasculitis is an autoimmune disease of unknown etiology that causes inflammation of the blood vessels. Large vessel vasculitis is classified as either giant cell arteritis (GCA), which occurs exclusively in the elderly, or Takayasu arteritis (TAK), which mainly affects young women. Various cell types are involved in the pathogenesis of large vessel vasculitis. Among these, dendritic cells located between the adventitia and the media initiate the inflammatory cascade as antigen-presenting cells, followed by activation of macrophages and T cells contributing to vessel wall destruction. In both diseases, naive CD4⁺ T cells are polarized to differentiate into Th1 or Th17 cells, whereas differentiation into regulatory T cells, which suppress vascular inflammation, is inhibited. Skewed T cell differentiation is the result of aberrant intracellular signaling, such as the mechanistic target of rapamycin (mTOR) or the Janus kinase signal transducer and activator of transcription (JAK-STAT) pathways. It has also become clear that tissue niches in the vasculature fuel activated T cells and maintain tissue-resident memory T cells. In this review, we outline the most recent understanding of the pathophysiology of large vessel vasculitis. Then, we provide a summary of skewed T cell differentiation in the vasculature and peripheral blood. Finally, new therapeutic strategies for correcting skewed T cell differentiation as well as aberrant intracellular signaling are discussed.

Novel PET Imaging of Inflammatory Targets and Cells for the Diagnosis and Monitoring of Giant Cell Arteritis and Polymyalgia Rheumatica

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are two interrelated inflammatory diseases affecting patients above 50 years of age. Patients with GCA suffer from granulomatous inflammation of medium- to large-sized arteries. This inflammation can lead to severe ischemic complications (e.g., irreversible vision loss and stroke) and aneurysm-related complications (such as aortic dissection). On the other hand, patients suffering from PMR present with proximal stiffness and pain due to inflammation of the shoulder and pelvic girdles. PMR is observed in 40-60% of patients with GCA, while up to 21% of patients suffering from PMR are also affected by GCA. Due to the risk of ischemic complications, GCA has to be promptly treated upon clinical suspicion. The treatment of both GCA and PMR still heavily relies on glucocorticoids (GCs), although novel targeted therapies are emerging. Imaging has a central position in the diagnosis of GCA and PMR. While [18F]fluorodeoxyglucose (FDG)-positron emission tomography (PET) has proven to be a valuable tool for diagnosis of GCA and PMR, it possesses major drawbacks such as unspecific uptake in cells with high glucose metabolism, high background activity in several non-target organs and a decrease of diagnostic accuracy already after a short course of GC treatment. In recent years, our understanding of the immunopathogenesis of GCA and, to some extent, PMR has advanced. In this review, we summarize the current knowledge on the cellular heterogeneity in the immunopathology of GCA/PMR and discuss how recent advances in specific tissue infiltrating leukocyte and stromal cell profiles may be exploited as a source of novel targets for imaging. Finally, we discuss prospective novel PET radiotracers that may be useful for the diagnosis and treatment monitoring in GCA and PMR.

Looking ahead: giant-cell arteritis in 10 years time

Although great improvements have been achieved in the fields of diagnosing and treating patients with giant-cell arteritis (GCA) in the last decades, several questions remain unanswered. The progressive increase in the number of older people, together with growing awareness of the disease and use of advanced diagnostic tools by healthcare professionals, foretells a possible increase in both prevalence and number of newly diagnosed patients with GCA in the coming years. A thorough clarification of pathogenetic mechanisms and a better definition of clinical subsets are the first steps toward a better understanding of the disease and, subsequently, toward a better use of existing and future therapeutic options. Examination of the role of different imaging techniques for GCA diagnosing and monitoring, optimization, and personalization of glucocorticoids and other immunosuppressive agents, further development and introduction of novel drugs, identification of prognostic factors for long-term outcomes and management of treatment discontinuation will be the central topics of the research agenda in years to come.

New Insights into the Pathogenesis of Giant Cell Arteritis: Mechanisms Involved in Maintaining Vascular Inflammation

The giant cell arteritis (GCA) pathophysiology is complex and multifactorial, involving a predisposing genetic background, the role of immune aging and the activation of vascular dendritic cells by an unknown trigger. Once activated, dendritic cells recruit CD4 T cells and induce their activation, proliferation and polarization into Th1 and Th17, which produce interferon-gamma (IFN-γ) and interleukin-17 (IL-17), respectively. IFN-γ triggers the production of chemokines by vascular smooth muscle cells, which leads to the recruitment of additional CD4 and CD8 T cells and also monocytes that differentiate into macrophages. Recent data have shown that IL-17, IFN-γ and GM-CSF induce the differentiation of macrophage subpopulations, which play a role in the destruction of the arterial wall, in neoangiogenesis or intimal hyperplasia. Under the influence of different mediators, mainly endothelin-1 and PDGF, vascular smooth muscle cells migrate to the intima, proliferate and change their phenotype to become myofibroblasts that further proliferate and produce extracellular matrix proteins, increasing the vascular stenosis. In addition, several defects in the immune regulatory mechanisms probably contribute to chronic vascular inflammation in GCA: a defect in the PD-1/PD-L1 pathway, a quantitative and qualitative Treg deficiency, the implication of resident cells, the role of GM-CSF and IL-6, the implication of the NOTCH pathway and the role of mucosal‑associated invariant T cells and tissue‑resident memory T cells.

The Sound of Interconnectivity; The European Vasculitis Society 2022 Report

The first European Vasculitis Society (EUVAS) meeting report was published in 2017. Herein, we report on developments in the past 5 years which were greatly influenced by the pandemic. The adaptability to engage virtually, at this critical time in society, embodies the importance of networks and underscores the role of global collaborations. We outline state-of-the-art webinar topics, updates on developments in the last 5 years, and proposals for agendas going forward. A host of newly reported clinical trials is shaping practice on steroid minimization, maintenance strategies, and the role of newer therapies. To guide longer-term strategies, a longitudinal 10-year study investigating relapse, comorbidity, malignancy, and survival rates is at an advanced stage. Disease assessment studies are refining classification criteria to differentiate forms of vasculitis more fully. A large international validation study on the histologic classification of anti-neutrophil cytoplasmic antibody (ANCA) glomerulonephritis, recruiting new multicenter sites and comparing results with the Kidney Risk Score, has been conducted. Eosinophilic granulomatosis with polyangiitis (EGPA) genomics offers potential pathogenic subset and therapeutic insights. Among biomarkers, ANCA testing is favoring immunoassay as the preferred method for diagnostic evaluation. Consolidated development of European registries is progressing with an integrated framework to analyze large clinical data sets on an unprecedented scale.

Perspectives of JAK Inhibitors for Large Vessel Vasculitis

Vasculitis is an inflammation of the blood vessels caused by autoimmunity and/or autoinflammation, and recent advances in research have led to a better understanding of its pathogenesis. Glucocorticoids and cyclophosphamide have long been the standard of care. However, B-cell depletion therapy with rituximab has become available for treating antineutrophil cytoplasmic antibody-associated vasculitis (AAV). More recently, avacopan, an inhibitor of the complement 5a receptor, was shown to have high efficacy in remission induction against AAV. Thus, treatment options for AAV have been expanded. In contrast, in large vessel vasculitis (LVV), including giant cell arteritis and Takayasu arteritis, tocilizumab, an IL-6 receptor antagonist, was shown to be effective in suppressing relapse and has steroid-sparing effects. However, the relapse rate remains high, and other therapeutic options have long been awaited. In the last decade, Janus kinase (JAK) inhibitors have emerged as therapeutic options for rheumatoid arthritis (RA). Their efficacy has been proven in multiple studies; thus, JAK inhibitors are expected to be promising agents for treating other rheumatic diseases, including LVV. This mini-review briefly introduces the mechanism of action of JAK inhibitors and their efficacy in patients with RA. Then, the pathophysiology of LVV is updated, and a rationale for treating LVV with JAK inhibitors is provided with a brief introduction of our preliminary results using a mouse model. Finally, we discuss the newly raised safety concerns regarding JAK inhibitors and future perspectives for treating LVV.

Treatment of Giant Cell Arteritis (GCA)

Giant cell arteritis (GCA) is the most frequent primary large-vessel vasculitis in individuals older than 50. Glucocorticoids (GCs) are considered the cornerstone of treatment. GC therapy is usually tapered over months according to clinical symptoms and inflammatory marker levels. Considering the high rate of GC-related adverse events in these older individuals, immunosuppressive treatments and biologic agents have been proposed as add-on therapies. Methotrexate was considered an alternative option, but its clinical impact was limited. Other immunosuppressants failed to demonstrate a significant favourable benefit/risk ratio. The approval of tocilizumab, an anti-interleukin 6 (IL-6) receptor inhibitor brought significant improvement. Indeed, tocilizumab had a noticeable effect on cumulative GCs’ dose and relapse prevention. After the improvement in pathophysiological knowledge, other targeted therapies have been proposed, with anti-IL-12/23, anti-IL-17, anti-IL-1, anti-cytotoxic T-lymphocyte antigen 4, Janus kinase inhibitors or anti-granulocyte/macrophage colony stimulating factor therapies. These therapies are currently under evaluation. Interestingly, mavrilimumab, ustekinumab and, to a lesser extent, abatacept have shown promising results in phase 2 randomised controlled trials. Despite this recent progress, the value, specific condition and optimal application of each treatment remain undecided. In this review, we discuss the scientific rationale for each treatment and the therapeutic strategy.