Giant Cell Arteritis: Visual Loss Is Our Major Concern

Neuro-ophthalmic challenges and multi-morbidity in vasculitis among the older adults

INTRODUCTION

Vasculitides are a heterogeneous group of disorders producing inflammation of blood vessels (e.g. arteries or veins). All major vasculitides potentially have ophthalmological symptoms and signs including visual loss. Co-morbidity, multimorbidity, polypharmacy, and geriatric syndromes all play important roles in patient outcomes for these rheumatic conditions in the elderly. This monograph reviews the NCBI PubMed database (Feb 2023) literature on the neuro-ophthalmic and geriatric considerations in vasculitis.

AREAS COVERED

Cogan Syndrome, Granulomatosis with Polyangiitis, Giant Cell Arteritis, Polyarteritis Nodosa, Takayasu Arteritis, Vasculitis epidemiology, and neuro-ophthalmological symptoms.

EXPERT OPINION

Geriatric patient care for vasculitis with neuro-ophthalmological manifestations can be complicated by the interplay of multiple co-morbidities, polypharmacy, and specific geriatric syndromes. The valuation and treatment of vasculitis and the complications associated with the disease can negatively impact patient care. Advances in noninvasive imaging and updates in diagnostic criteria have enabled increased identification of patients at earlier stages with less severe disease burden. Novel therapeutic agents can be glucocorticoid sparing and might reduce the adverse effects of chronic steroid use. Holistic care models like the 5 M geriatric care model (mind, mobility, medications, multicomplexity, and matters most) allow patients' needs to be in the forefront with biopsychosocial aspects of a patient being addressed.

Broadening the clinical spectrum of giant cell arteritis: from the classic cranial to the predominantly extracranial pattern of the disease

INTRODUCTION

Giant cell arteritis (GCA) is a large vessel (LV) vasculitis that affects people aged 50 years and older. Classically, GCA was considered a disease that involved branches of the carotid artery. However, the advent of new imaging techniques has allowed us to reconsider the clinical spectrum of this vasculitis.

AREASCOVERED

This review describes clinical differences between patients with the cranial GCA and those with a predominantly extracranial LV-GCA disease pattern. It highlights differences in the frequency of positive temporal artery biopsy depending on the predominant disease pattern and emphasizes the relevance of imaging techniques to identify patients with LV-GCA without cranial ischemic manifestations. The review shows that so far there are no well-established differences in genetic predisposition to GCA regardless of the predominant phenotype.

EXPERT COMMENTARY

The large branches of the extracranial arteries are frequently affected in GCA. Imaging techniques are useful to identify the presence of 'silent' GCA in people presenting with polymyalgia rheumatica or with nonspecific manifestations. Whether these two different clinical presentations of GCA constitute a continuum in the clinical spectrum of the disease or whether they may be related but are definitely different conditions needs to be further investigated.

Giant-cell arteritis related strokes: scoping review of mechanisms and rethinking treatment strategy?

Stroke is a rare and severe complication of giant cell arteritis (GCA). Although early diagnosis and treatment initiation are essential, the mechanism of stroke is often related to vasculitis complicated by arterial stenosis and occlusion. Its recurrence is often attributed to early steroid resistance or late GCA relapse, so immunosuppressive treatment is often reinforced. However, many questions concerning the mechanisms of stroke remain elusive, and no review to date has examined the whole data set concerning GCA-related stroke. We therefore undertook this scoping review. GCA-related stroke does not necessarily display general signs and inflammatory parameters are sometimes normal, so clinicians should observe caution. Ischemic lesions often show patterns predating watershed areas and are associated with stenosis or thrombosis of the respective arteries, which are often bilateral. Lesions predominate in the siphon in the internal carotid arteries, whereas all the vertebral arteries may be involved with a predominance in the V3-V4 segments. Ultrasonography of the cervical arteries may reveal edema of the intima (halo sign), which is highly sensitive and specific of GCA, and precedes stenosis. The brain arteries are spared although very proximal arteritis may rarely occur, if the patient has microstructural anatomical variants. Temporal artery biopsy reveals the combination of mechanisms leading to slit-like stenosis, which involves granulomatous inflammation and intimal hyperplasia. The lumen is sometimes occluded by thrombi (<15%), suggesting that embolic lesions may also occur, although imaging studies have not provided strong evidence for this. Moreover, persistence of intimal hyperplasia might explain persisting arterial stenosis, which may account for delayed stroke occurring in watershed areas. Other possible mechanisms of stroke are also discussed. Overall, GCA-related stroke mainly involves hemodynamic mechanisms. Besides early diagnosis and treatment initiation, future studies could seek to establish specific preventive or curative treatments using angioplasty or targeting intimal proliferation.

Evolution of the Therapeutic Management of Giant Cell Arteritis: Analysis of Real-Life Practices over Two Timeframes (2014-2017 and 2018-2020)

Objectives: To determine how therapeutic strategies for giant cell arteritis (GCA), especially glucocorticoid (GC) management, evolved between 2014 and 2020. Patients and Methods: Consecutive GCA patients followed for at least 24 months in a single tertiary center were enrolled and separated into two groups: those diagnosed from 2014 to 2017 and those diagnosed from 2018 to 2020. GC doses (mg/kg/day) were analyzed at onset, at Month 3 (M3) and, if continued, at M6, M12, M18 and M24. Physicians' practices were also individually analyzed. Results: Among the 180 patients included, 96 (53%) were diagnosed in 2014-2017 and 84 (47%) in 2018-2020. All patients received GC at diagnosis without a difference in the initial dose between the two groups (p = 0.07). At M3, the daily dose was lower in patients treated after 2017 (p = 0.002). In patients who still received GC at M6 (p = 0.0008), M12 (p = 0.01) and M24 (p = 0.02), the daily GC dose was still lower in patients treated after 2017. The proportion of patients who definitively discontinued GC use before M18 (42% versus 21%, p = 0.003) was higher in those treated after 2017. The rates of immunosuppressant use were not different between the two time periods (31% versus 38%, p = 0.34), but tocilizumab replaced methotrexate. Significant differences were observed among practitioners regarding the GC doses at M6 (p = 0.04) and M12 (p = 0.04), the total GC duration (p = 0.02) and the ability to stop GC before M18 (p = 0.007). Conclusions: This real-life study showed a global change in GC management over time for GCA patients, with important variability among physicians' practices.

Challenges in the diagnosis of polymyalgia rheumatica and related giant cell arteritis

INTRODUCTION

Polymyalgia rheumatica (PMR) has emerged as a relatively common condition in Western countries. Although the diagnosis is relatively straightforward in people over 50 years of age who complain of sudden onset of pain and stiffness in the shoulder and hip girdles along with elevation of biomarkers of inflammation, manifestations of polymyalgia can also occur in the context of different conditions. For this reason, a complete history and examination is required, including looking for symptoms and signs suggestive of giant cell arteritis (GCA).

AREAS COVERED

The review describes when and how to identify PMR, as well as when to suspect the presence of associated GCA or multiple conditions mimicking PMR.

EXPERT OPINION

PMR does not have a specific diagnostic test. For this reason, a thorough clinical history searching for clinical data of GCA is needed. Moreover, the possibility of other diseases mimicking PMR should be considered, particularly when atypical presentation or unusual clinical data are present.

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.

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.

Tocilizumab in visual involvement of giant cell arteritis: a multicenter study of 471 patients

Background:

Visual involvement is the most feared complication of giant cell arteritis (GCA). Information on the efficacy of tocilizumab (TCZ) for this complication is scarce and controversial.

Objective:

We assessed a wide series of GCA treated with TCZ, to evaluate its role in the prevention of new visual complications and its efficacy when this manifestation was already present before the initiation of TCZ.

Design:

This is an observational multicenter study of patients with GCA treated with TCZ.

Methods:

Patients were divided into two subgroups according to the presence or absence of visual involvement before TCZ onset. Visual manifestations were classified into the following categories: transient visual loss (TVL), permanent visual loss (PVL), diplopia, and blurred vision.

Results:

Four hundred seventy-one GCA patients (mean age, 74 ± 9 years) were treated with TCZ. Visual manifestations were observed in 122 cases (26%), of which 81 were present at TCZ onset: PVL (n = 60; unilateral/bilateral: 48/12), TVL (n = 17; unilateral/bilateral: 11/6), diplopia (n = 2), and blurred vision (n = 2). None of the patients without previous visual involvement or with TVL had new episodes after initiation of TCZ, while only 11 out of 60 (18%) patients with PVL experienced some improvement. The two patients with diplopia and one of the two patients with blurred vision improved.

Conclusion:

TCZ may have a protective effect against the development of visual complications or new episodes of TVL in GCA. However, once PVL was established, only a few patients improved.

Advances in the Treatment of Giant Cell Arteritis

Giant cell arteritis (GCA) is the most common vasculitis among elderly people. The clinical spectrum of the disease is heterogeneous, with a classic/cranial phenotype, and another extracranial or large vessel phenotype as the two more characteristic patterns. Permanent visual loss is the main short-term complication. Glucocorticoids (GC) remain the cornerstone of treatment. However, the percentage of relapses with GC alone is high, and the rate of adverse events affects more than 80% of patients, so it is necessary to have alternative therapeutic options, especially in patients with worse prognostic factors or high comorbidity. MTX is the only DMARD that has shown to reduce the cumulative dose of GC, while tocilizumab is the first biologic agent approved due to its ability to decrease the relapse rate and lower the cumulative GC doses. However, apart from the IL-6 pathway, there are other pro-inflammatory cytokines and growth factors involved in the typical intima hyperplasia and vascular remodeling of GCA. Among them, the more promising targets in GCA treatment are the IL12/IL23 axis antagonists, IL17 inhibitors, modulators of T lymphocytes, and inhibitors of either the JAK/STAT pathway, the granulocyte-macrophage colony-stimulating factor, or the endothelin, all of which are updated in this review.

Novel aspects of regulatory T cell dysfunction as a therapeutic target in giant cell arteritis

OBJECTIVES

Giant cell arteritis (GCA) is the most common primary vasculitis, preferentially affecting the aorta and its large-calibre branches. An imbalance between proinflammatory CD4+ T helper cell subsets and regulatory T cells (Tregs) is thought to be involved in the pathogenesis of GCA and Treg dysfunction has been associated with active disease. Our work aims to explore the aetiology of Treg dysfunction and the way it is affected by remission-inducing immunomodulatory regimens.

METHODS

A total of 41 GCA patients were classified into active disease (n=14) and disease in remission (n=27). GCA patients' and healthy blood donors' (HD) Tregs were sorted and subjected to transcriptome and phenotypic analysis.

RESULTS

Transcriptome analysis revealed 27 genes, which were differentially regulated between GCA-derived and HD-derived Tregs. Among those, we identified transcription factors, glycolytic enzymes and IL-2 signalling mediators. We confirmed the downregulation of forkhead box P3 (FOXP3) and interferon regulatory factor 4 (IRF4) at protein level and identified the ineffective induction of glycoprotein A repetitions predominant (GARP) and CD25 as well as the reduced T cell receptor (TCR)-induced calcium influx as correlates of Treg dysfunction in GCA. Inhibition of glycolysis in HD-derived Tregs recapitulated most identified dysfunctions of GCA Tregs, suggesting the central pathogenic role of the downregulation of the glycolytic enzymes. Separate analysis of the subgroup of tocilizumab-treated patients identified the recovery of the TCR-induced calcium influx and the Treg suppressive function to associate with disease remission.

CONCLUSIONS

Our findings suggest that low glycolysis and calcium signalling account for Treg dysfunction and inflammation in GCA.

Imaging Tests in the Early Diagnosis of Giant Cell Arteritis

Early recognition of giant cell arteritis (GCA) is crucial to avoid the development of ischemic vascular complications, such as blindness. The classic approach to making the diagnosis of GCA is based on a positive temporal artery biopsy, which is among the criteria proposed by the American College of Rheumatology (ACR) in 1990 to classify a patient as having GCA. However, imaging techniques, particularly ultrasound (US) of the temporal arteries, are increasingly being considered as an alternative for the diagnosis of GCA. Recent recommendations from the European League Against Rheumatism (EULAR) for the use of imaging techniques for large vessel vasculitis (LVV) included US as the first imaging option for the diagnosis of GCA. Furthermore, although the ACR classification criteria are useful in identifying patients with the classic cranial pattern of GCA, they are often inadequate in identifying GCA patients who have the extracranial phenotype of LVV. In this sense, the advent of other imaging techniques, such as magnetic resonance imaging (MRI), computed tomography (CT), and positron emission tomography (PET)/CT, has made it possible to detect the presence of extracranial involvement of the LVV in patients with GCA presenting as refractory rheumatic polymyalgia without cranial ischemic manifestations. Imaging techniques have been the key elements in redefining the diagnostic work-up of GCA. US is currently considered the main imaging modality to improve the early diagnosis of GCA.

[Giant Cell Arteritis. Recommendations in Primary Care]

Giant cell arteritis is a systemic vasculitis with significant intra and extracranial involvement that, with early diagnosis and treatment in primary care, can improve its prognosis as it is a medical emergency. Our working group on vascular diseases of the Spanish Society of Primary Care Physicians (SEMERGEN) proposes a series of recommendations based on current scientific evidence for a multidisciplinary approach and follow-up in primary care.

A Review of the Dermatological Complications of Giant Cell Arteritis

Giant cell arteritis (GCA) is characterized by granulomatous inflammation of large and medium-sized vessels. It is the most common vasculitis among elderly people in Europe and North America. GCA usually presents with ischemic cranial manifestations such as headache, scalp tenderness, visual manifestations, and claudication of the tongue and jaw. Thickness and tenderness of temporal arteries are the most recognizable signs of GCA on physical examination. Laboratory tests usually show raised acute phase reactants. Skin manifestations are uncommon in GCA and are rarely found as a presenting symptom of GCA. Necrosis of the scalp and tongue is the most common ischemic cutaneous manifestation of GCA. Although infrequent, when present it reflects severe affection and poor prognosis of GCA. Panniculitis-like lesions have been reported in the setting of GCA, with nodules being the most common finding. Other entities, such as generalized granuloma annulare or basal cell carcinoma have been occasionally described in GCA patients. Prompt recognition and initiation of therapy are crucial to prevent serious complications of GCA. When high suspicion of GCA exists, immediate administration of glucocorticoids is recommended. It is advisable to refer the patient to a specialist GCA team for further multidisciplinary assessment.

Vision loss in patients with giant cell arteritis treated with tocilizumab

Objectives

Giant cell arteritis (GCA) may lead to vision loss. To what extent tocilizumab (TCZ) is able to prevent vision loss is unknown. The aim was to analyze the occurrence of vision loss in a large GCA cohort treated with TCZ.

Methods

In this observational monocentric study, GCA patients treated with TCZ between the years 2010 and 2018 were studied. Demographic, clinical, and laboratory data were analyzed.

Results

A total of 186 patients were included (62% female); 109 (59%) fulfilled the American College of Rheumatology (ACR) criteria, in 123 (66%) patients, large vessel vasculitis was diagnosed by magnetic resonance-angiography (MRA). Cumulative duration of TCZ treatment was 224 years, median treatment duration was 11.1 (IQR 5.6–17.9) months. Glucocorticoids (GC) were tapered over a median of 5.8 (IQR 3.0–8.5) months. At baseline, visual symptoms were present in 70 (38%) and vision loss in 21 (11%) patients. Patients with vision loss at baseline were older (p = 0.032), had a lower C-reactive protein (p = 0.002), and showed a negative association with MRA of the aorta (p = 0.006). Two patients (1.1%) developed vision loss, both at the initiation of TCZ treatment.

Conclusion

Our data show a very low incidence of vision loss in TCZ-treated patient. The two cases of AION occurred at the initiation of therapy, they support the hypothesis that advanced, and established structural changes of arteries are key factors for this accident. Whether a shorter duration of concomitant GC treatment is risky regarding vision loss needs to be studied.

Biologic Therapies for Giant Cell Arteritis

Glucocorticoids have been the mainstay of treatment in giant cell arteritis (GCA) for the past 70 years. Conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) have largely failed to show significant clinical efficacy or reduction of the glucocorticoid burden in GCA. Tocilizumab is the first biologic to make a substantial impact in GCA treatment. With the current understanding of GCA pathogenesis implicating multiple cytokines, notably interleukin (IL) 6, IL-12, IL-23, IL-1β, and the role of janus kinases (JAKs) and the signal transducer and activator of transcription (STAT) pathway in these cytokines, many biologics are currently being investigated in GCA. This review article looks at the existing evidence for biologic agents in GCA. In addition to tocilizumab, the potential role of ustekinumab, abatacept, JAK inhibitors and other promising biologics in GCA are discussed in detail. A treatment algorithm based on the best evidence to date is also presented.

Giant cell arteritis: is the clinical spectrum of the disease changing?

Background

Giant cell arteritis is a vasculitis of large and middle-sized arteries that affects patients aged over 50 years. It can show a typical clinical picture consisting of cranial manifestations but sometimes nonspecific symptoms and large-vessel involvement prevail. Prompt diagnosis and treatment is essential to avoid irreversible damage.

Discussion

There has been an increasing knowledge on the occurrence of the disease without the typical cranial symptoms and its close relationship and overlap with polymyalgia rheumatica, and this may contribute to reduce the number of underdiagnosed patients. Although temporal artery biopsy is still the gold-standard and temporal artery ultrasonography is being widely used, newer imaging techniques (FDG-PET/TAC, MRI, CT) can be of valuable help to identify giant cell arteritis, in particular in those cases with a predominance of extracranial large-vessel manifestations.

Conclusions

Giant cell arteritis is a more heterogeneous condition than previously thought. Awareness of all the potential clinical manifestations and judicious use of diagnostic tests may be an aid to avoid delayed detection and consequently ominous complications.

Genetic Basis of Vasculitides with Neurologic Involvement

"Vasculitides are a heterogeneous group of inflammatory diseases of blood vessels in which genetic variation plays an important role in their susceptibility and clinical spectrum. Because of the use of novel technologies and the increase of the sample size of the study cohorts, the knowledge of the genetic background of vasculitides has considerably expanded during the last years. However, few insights have been obtained regarding the genetics underlying severe clinical phenotypes, such as those related to the nervous system. In this review the authors provide an updated overview of the genetic landscape behind vasculitis predisposition and development of neurologic manifestations."

Visual loss in giant cell arteritis 3 weeks after steroid initiation

Giant cell arteritis (GCA) is the most common vasculitis in adults and blindness is a common complication if left untreated. Oral glucocorticoids are the mainstay of treatment and if started promptly, loss of vision can usually be prevented. We present the case of a 77-year-old man who developed irreversible bilateral blindness after a confirmed diagnosis of GCA and oral steroid treatment. The roles of diagnostic delay, steroid dosing, significance of visual symptoms at diagnosis and after commencing oral glucocorticoids, and interpretation of ophthalmological signs are reviewed.

Adverse Events in Giant Cell Arteritis and Rheumatoid Arthritis Patient Populations: Analyses of Tocilizumab Clinical Trials and Claims Data

INTRODUCTION

The safety profile of tocilizumab (TCZ) in patients with rheumatoid arthritis (RA) is well established. TCZ was approved to treat giant cell arteritis (GCA) in 2017 in the USA and Europe, and its safety profile in patients with GCA continues to be defined. The objective of this analysis was to examine incidence rates (IRs) of adverse events of special interest (AESI) occurring during the TCZ clinical development program and in healthcare claims data in patients with GCA or RA.

METHODS

TCZ-naïve patients with GCA or RA were identified in the MarketScan administrative healthcare claims database. TCZ-treated patients with GCA from the GiACTA trial and TCZ-treated patients with RA from pooled clinical trial data were analyzed. The IRs of AESI (AESI IRs) were calculated for all cohorts. In the claims cohorts, risks of AESI were estimated using Poisson regression.

RESULTS

TCZ-naïve claims cohorts comprised 4804 patients with GCA [mean (standard deviation) age 73.4 (9.8) years; follow-up 3.9 (3.1) years] and 15,164 patients with RA [age 60.3 (8.2) years; follow-up, 4.5 (2.8) years]. TCZ-treated clinical trial cohorts comprised 149 patients with GCA [age 69.5 (8.4) years; exposure approx. 138 patient-years (PY)] and 7647 with RA [age 52 (12.6) years; exposure approx. 22,394 PY]. The IRs of infections, stroke, malignancies, myocardial infarction, and gastrointestinal perforations in the GCA claims cohort exceeded those in the RA claims cohort; the risk of AESI (adjusted for age and glucocorticoid use) was higher in patients with GCA than in those with RA. Similar patterns to the claims cohorts in terms of the AESI IRs were observed in clinical trial cohorts, although the number of events was limited in the GCA trial cohort.

CONCLUSION

Higher IRs of AESI were observed in patients with GCA versus those with RA in both TCZ-naïve and -treated cohorts. Differences in underlying disease, age, and glucocorticoid use may influence AESI incidence, irrespective of intervention.

FUNDING

This study was funded by F. Hoffmann-La Roche Ltd and Genentech, Inc. Article processing charges were funded by F. Hoffmann-La Roche Ltd. Plain language summary is available for this article.

Risk Associated with Cumulative Oral Glucocorticoid Use in Patients with Giant Cell Arteritis in Real-World Databases from the USA and UK

INTRODUCTION

Treatment of giant cell arteritis (GCA) involves immediate initiation of high-dose glucocorticoid therapy with slow tapering of the dose over many months. Chronic exposure to glucocorticoids is associated with serious comorbidities. The objective of this analysis was to determine the glucocorticoid exposure and risk of glucocorticoid-related adverse events (AEs) in real-world patients with GCA.

METHODS

Data from the Truven Healthcare MarketScan^® database (from January 1, 2000, to June 30, 2015) and the Clinical Practice Research Datalink (CPRD; from January 1, 1995, to August 31, 2013) were used to retrospectively analyze patients aged ≥ 50 years with GCA in the USA and UK, respectively. Outcomes included oral glucocorticoid use (cumulative prednisone-equivalent exposure), glucocorticoid-related AEs and the association of AE risk with glucocorticoid exposure over 52 weeks.

RESULTS

Of the 4804 patients in the US MarketScan database and 3973 patients in the UK CPRD database included, 71.3 and 74.6% were women and mean age was 73.4 and 73.0 years, respectively. Median starting glucocorticoid dose and cumulative glucocorticoid dose at 52 weeks were 20-50 mg/day and 4000-4800 mg, respectively. The most frequent glucocorticoid-related AEs were hypertension and eye, bone health, and glucose tolerance conditions. In the first year after diagnosis, the likelihood of any glucocorticoid-related AE was significantly increased for each 1 g increase in cumulative glucocorticoid dose in the US and UK cohorts (odds ratio [95% CI], 1.170 [1.063, 1.287] and 1.06 [1.03, 1.09], respectively; P < 0.05 for both). Similar trends were observed for the risk of glucocorticoid-related AEs over full follow-up (mean, USA: 3.9 years, UK: 6.3 years).

CONCLUSIONS

In real-world patients with GCA, increased cumulative glucocorticoid exposure was associated with an increased risk of glucocorticoid-related AEs.

FUNDING

F. Hoffmann-La Roche Ltd. Plain language summary available for this article.

Tocilizumab in the treatment of giant cell arteritis

Giant cell arteritis is a systemic vasculitis of large vessels, manifesting mainly as temporal arteritis or large vessel vasculitis of the aorta and its branches. Glucocorticoid therapy is essential and so far had to be continued over a period of 1.5–2 years, resulting in relevant morbidity through adverse effects. With the approval of tocilizumab, an effective glucocorticoid sparing option is now available. In two randomized controlled trials, a profound reduction of cumulative glucocorticoid dose, prolonged relapse-free remission and reduced number of adverse events in the treatment groups have been demonstrated. Therefore, tocilizumab constitutes a novel therapeutic option in giant cell arteritis. Its differential role in different subgroups, timing of tocilizumab therapy and optimal treatment duration remain to be determined.

Profile of tocilizumab and its potential in the treatment of giant cell arteritis

Giant cell arteritis (GCA) remains a medical emergency due to the threat of permanent sight loss. High-dose glucocorticoids (GCs) are effective in inducing remission in the majority of patients, however, relapses are common which lengthen GC therapy. GC toxicity remains a major morbidity in this group of patients, and conventional steroid-sparing therapies have not yet shown enough of a clinical benefit to change the standard of care. As the understanding of the underlying immunopathophysiology of GCA has increased, positive clinical observations have been made with the use of IL-6 receptor inhibitor therapies, such as tocilizumab (TCZ). This has led to prospective randomized control trials that have highlighted the safety and efficacy of TCZ in both new-onset and relapsing GCA.

Visual loss and other cranial ischaemic complications in giant cell arteritis

Giant cell arteritis (GCA) is the most common form of vasculitis in individuals aged 50 years and over. GCA typically affects large and medium-sized arteries, with a predilection for the extracranial branches of the carotid artery. Patients with GCA usually present with symptoms and signs that are directly related to the artery that is affected, with or without constitutional manifestations. The most dreaded complication of GCA is visual loss, which affects about one in six patients and is typically caused by arteritis of the ophthalmic branches of the internal carotid artery. Before the advent of glucocorticoid treatment, the prevalence of visual complications was high. Increasing awareness by physicians of the symptoms of GCA and advances in diagnostic techniques over the past twenty years have also contributed to a substantial decline in the frequency of permanent visual loss. Ischaemic brain lesions are less common than visual lesions, and mostly result from vasculitis of the extradural vertebral or carotid arteries. In the case of both the eye and the brain, ischaemic damage is thought to result from arterial stenosis or occlusion that occurs secondary to the inflammatory process. The inflammatory response at the onset of arteritis, its role as a predictor of complications and the role of traditional cardiovascular risk factors have been extensively investigated in the past decade. In this Review, the epidemiology, risk factors, clinical presentation and current therapeutic approach of GCA-related ischaemic events are discussed, with a particular emphasis on visual loss.