Large-vessel involvement in recent-onset giant cell arteritis: a case-control colour-Doppler sonography study

Multi-Modality Imaging in Vasculitis

Systemic vasculitides are a rare and complex group of diseases that can affect multiple organ systems. Clinically, presentation may be vague and non-specific and as such, diagnosis and subsequent management are challenging. These entities are typically classified by the size of vessel involved, including large-vessel vasculitis (giant cell arteritis, Takayasu's arteritis, and clinically isolated aortitis), medium-vessel vasculitis (including polyarteritis nodosa and Kawasaki disease), and small-vessel vasculitis (granulomatosis with polyangiitis and eosinophilic granulomatosis with polyangiitis). There are also other systemic vasculitides that do not fit in to these categories, such as Behcet's disease, Cogan syndrome, and IgG4-related disease. Advances in medical imaging modalities have revolutionized the approach to diagnosis of these diseases. Specifically, color Doppler ultrasound, computed tomography and angiography, magnetic resonance imaging, positron emission tomography, or invasive catheterization as indicated have become fundamental in the work up of any patient with suspected systemic or localized vasculitis. This review presents the key diagnostic imaging modalities and their clinical utility in the evaluation of systemic vasculitis.

Giant Cell Arteritis after COVID-19 Vaccination with Long-Term Follow-Up: A Case Report and Review of the Literature

Giant cell arteritis (GCA) is a chronic vasculitis that primarily affects the elderly, and can cause visual impairment, requiring prompt diagnosis and treatment. The global impact of the coronavirus disease 2019 (COVID-19) pandemic has been substantial. Although vaccination programs have been a key defense strategy, concerns have arisen regarding post-vaccination immune-mediated disorders and related risks. We present a case of GCA after COVID-19 vaccination with 2 years of follow-up. A 69-year-old woman experienced fever, headaches, and local muscle pain two days after receiving the COVID-19 vaccine. Elevated inflammatory markers were observed, and positron emission tomography (PET) revealed abnormal uptake in the major arteries, including the aorta and subclavian and iliac arteries. Temporal artery biopsy confirmed the diagnosis of GCA. Treatment consisted of pulse therapy with methylprednisolone, followed by prednisolone (PSL) and tocilizumab. Immediately after the initiation of treatment, the fever and headaches disappeared, and the inflammation markers normalized. The PSL dosage was gradually reduced, and one year later, a PET scan showed that the inflammation had resolved. After two years, the PSL dosage was reduced to 3 mg. Fourteen reported cases of GCA after COVID-19 vaccination was reviewed to reveal a diverse clinical picture and treatment response. The time from onset of symptoms to GCA diagnosis varied from two weeks to four months, highlighting the challenge of early detection. The effectiveness of treatment varied, but was generally effective similarly to that of conventional GCA. This report emphasizes the need for clinical vigilance and encourages further data collection in post-vaccination GCA cases.

Clinical phenotype and complications of large vessel giant cell arteritis: A systematic review and meta-analysis

BACKGROUND

Giant Cell Arteritis (GCA) is a heterogenous systemic granulomatous vasculitis involving the aorta and any of its major tributaries. Despite increased awareness of large vessel (LV) involvement, studies reporting incidence, clinical characteristics and complications of large-vessel GCA (LV-GCA) show conflicting results due to inconsistent disease definitions, differences in study methodologies and the broad spectrum of clinical presentations. The aim of this systematic literature review was to better define LV-GCA based on the available literature and identify distinguishing characteristics that may differentiate LV-GCA patients from those with limited cranial disease.

METHODS

Published studies indexed in MEDLINE and EMBASE were searched from database inception to 7th May 2021. Studies were included if they presented cohort or cross-sectional data on a minimum of 25 patients with LV-GCA. Control groups were included if data was available on patients with limited cranial GCA (C-GCA). Data was quantitatively synthesised with application of a random effects meta-regression model, using Stata.

RESULTS

The search yielded 3488 studies, of which 46 were included. Diagnostic criteria for LV-GCA differed between papers, but was typically dependent on imaging or histopathology. Patients with LV-GCA were generally younger at diagnosis compared to C-GCA patients (mean age difference -4.53 years), had longer delay to diagnosis (mean difference 3.03 months) and lower rates of positive temporal artery biopsy (OR: 0.52 [95% CI: 0.3, 0.91]). Fewer LV-GCA patients presented with cranial manifestations and only 53% met the 1990 ACR Classification Criteria for GCA. Vasculitis was detected most commonly in the thoracic aorta, followed by the subclavian, brachiocephalic trunk and axillary arteries. The mean cumulative prednisolone dose at 12-months was 6056.5mg for LV-GCA patients, relapse rates were similar between LV- and C-GCA patients, and 12% of deaths in LV-GCA patients could be directly attributed to an LV complication.

CONCLUSION

Patients with LV-GCA have distinct disease features when compared to C-GCA, and this has implications on diagnosis, treatment strategies and surveillance of long-term sequalae.

Diagnostic validity of ultrasound including extra-cranial arteries in giant cell arteritis

OBJECTIVES

Color Doppler ultrasound (CDUS) of the temporal arteries (TA) is becoming the first test to be performed for suspected giant cell arteritis (GCA). Our aim was to assess the added value of including CDUS of large vessels (LV) in the diagnosis of GCA.

METHODS

We performed an observational and retrospective study of consecutive patients with suspected GCA. Baseline CDUS of the TA and LV (axillary, subclavian, and carotid) were conducted. We defined the CDUS finding as positive if the halo sign was present.

RESULTS

Of 198 patients with suspected GCA, 87 were eventually diagnosed with GCA: 45 (51.7%) had a cranial pattern exclusively, 31 (35.6%) had both a cranial and an LV pattern, and 11 (12.6%) had an isolated LV pattern. CDUS of the TA had a sensitivity of 83.9%, specificity of 97.3%, and positive and negative predictive values (PPV, NPV) of 96.1% and 88.5%, respectively. When LV was added, sensitivity increased to 96.6% and NPV to 98.2%. Specificity was 97.3% and PPV was 96.6%. As for LVs, the axillary, subclavian, and carotid arteries were involved in 87.8%, 77.4%, and 34.4%, respectively. Isolated axillary examination resulted in a loss of 12.2% of patients with LV involvement; however, inclusion of the axillary and subclavian arteries retained 100% of patients with LV involvement.

CONCLUSIONS

Detection of GCA by ultrasound should routinely include examinations of the TA and LV (at least the axillary and subclavian arteries) to improve diagnostic accuracy. More than 12% of patients in our cohort had isolated LV involvement. Key Points • Extracranial involvement in GCA is very common: half of patients have extracranial vasculitis and more than 12% isolated LV involvement that can be demonstrated with CDUS. • Adding a CDUS examination of LV to TA increased sensitivity (from 83.9 to 96.6%) and the negative predictive value (from 88.5 to 98.2%) for diagnosis of GCA. • In our cohort, if we only examined the axillary arteries, 12.2% of the CGA with LV involvement would not have been diagnosed. • We propose a CDUS protocol that includes examination of the TA and LV (at least the axillary and subclavian arteries) routinely in cases of suspected GCA.

The Usefullness of Subclavian Artery Ultrasound Assessment in Giant Cell Arteritis Evaluation

OBJECTIVE

Vascular ultrasound has been increasingly used to diagnose giant cell arteritis (GCA). The temporal and axillary arteries are commonly evaluated. However, the usefulness of including the subclavian artery remains unclear. This study investigated whether inclusion of the subclavian artery in addition to the temporal and axillary arteries in the ultrasound evaluation of GCA improves the accuracy of the examination beyond ultrasonography of the temporal and axillary arteries alone.

METHODS

We formed a fast-track clinic to use ultrasound to rapidly evaluate patients with suspected GCA. In this cohort study, patients referred for new concern for GCA received a vascular ultrasound for GCA. Subclavian intima-media thickness (IMT) cutoffs of 1.0 and 1.5 mm were retrospectively assessed.

RESULTS

Two hundred thirty-seven patients were referred to the fast-track clinic from November 2017 to August 2021. One hundred sixty-eight patients received an ultrasound for concern for new GCA. With a subclavian IMT cutoff of 1.5 mm, inclusion of the subclavian artery did not identify any patients with GCA who were not otherwise found to have positive temporal and/or axillary artery examinations, and at this cutoff, there was 1 false-positive result. A subclavian IMT cutoff of 1.0 mm identified several subjects diagnosed with GCA who had otherwise negative ultrasounds, but most subjects with an isolated subclavian IMT greater than 1.0 mm had false-positive results, and the specificity of this cutoff was poor.

CONCLUSION

Inclusion of the subclavian artery in the ultrasound assessment of GCA at 2 different cutoffs rarely contributed to the accurate diagnosis of GCA and increased the rate of false-positive results.

Intima-media thickness cut-off values depicting "halo sign" and potential confounder analysis for the best diagnosis of large vessel giant cell arteritis by ultrasonography

Background

Vascular ultrasound enables fast-track diagnosis of giant cell arteritis (GCA), but this method remains subjective. We aimed to determine intima-media thickness (IMT) cut-off values for large vessel GCA (LV-GCA) and identify the clinically relevant factors influencing it.

Methods

We included 214 patients referred for ultrasound evaluation within a fast-track clinic due to suspected GCA. IMT was measured in axillary, brachial, subclavian, superficial femoral, and common carotid arteries (CCA), in a place without identifiable atherosclerotic plaques. IMT cut-off values for vasculitis were determined by comparing measurements in arteries classified as vasculitis vs. controls without GCA/polymyalgia rheumatica (PMR).

Results

Giant cell arteritis was diagnosed in 81 individuals, including extracranial LV-GCA in 43 individuals. Isolated PMR was diagnosed in 50 subjects. In 83 remaining patients, another diagnosis was confirmed, and they served as controls. The rounded optimal IMT cut-off values for the diagnosis of axillary vasculitis were 0.8 mm, subclavian-0.7 mm, superficial femoral-0.9 mm, CCA-0.7 mm, and brachial-0.5 mm. The IMT cut-off values providing 100% specificity for vasculitis (although with reduced sensitivity) were obtained with axillary IMT 1.06 mm, subclavian-1.35 mm, superficial femoral-1.55 mm, CCA-1.27 mm, and brachial-0.96 mm. Axillary and subclavian arteritis provided the best AUC for the diagnosis of GCA, while carotid and axillary were most commonly involved (24 and 23 patients, respectively). The presence of calcified atherosclerotic plaques was related to an increase of IMT in both patients and controls, while male sex, age ≥ 68, hypertension, and smoking increased IMT in controls but not in patients with GCA.

Conclusion

Cut-off values for LV-GCA performed best in axillary and subclavian arteritis but expanding examination to the other arteries may add to the sensitivity of GCA diagnosis (another location, e.g., brachial arteritis) and its specificity (identification of calcified atherosclerotic plaques in other arteries such as CCA, which may suggest applying higher IMT cut-off values). We proposed a more linear approach to cut-off values with two values: one for the most accurate and the other for a highly specific diagnosis and also considering some cardiovascular risk factors.

Giant cell arteritis: A population-based retrospective cohort study exploring incidence and clinical presentation in Canterbury, Aotearoa New Zealand

BACKGROUND/AIM

To determine the epidemiology and clinical features of giant cell arteritis (GCA) in Canterbury, Aotearoa New Zealand, with a particular focus on extra-cranial large vessel disease.

METHODS

Patients with GCA were identified from radiology and pathology reports, outpatient letters and inpatient hospital admissions in the Canterbury New Zealand from 1 June 2011 to 31 May 2016. Data was collected retrospectively based on review of electronic medical records.

RESULTS

There were 142 cases of GCA identified. 65.5% of cases were female with a mean age of 74.2 years. The estimated population incidence for biopsy-proven GCA was 10.5 per 100,000 people over the age of 50 and incidence peaked between 80 and 84 years of age. 10/142 (7%) people were diagnosed with large vessel GCA, often presenting with non-specific symptoms and evidence of vascular insufficiency including limb claudication, vascular bruits, blood pressure and pulse discrepancy, or cerebrovascular accident. Those with limited cranial GCA were more likely to present with the cardinal clinical features of headache and jaw claudication. Patients across the two groups were treated similarly, but those with large vessel disease had greater long-term steroid burden. Rates of aortic complication were low across both groups, although available follow-up data was limited.

CONCLUSION

This study is the first of its kind to describe the clinical characteristics of large vessel GCA in a New Zealand cohort. Despite small case numbers, two distinct subsets of disease were recognized, differentiating patients with cranial and large vessel disease. Our results suggest that utilization of an alternative diagnostic and therapeutic approach may be needed to manage patients with large vessel disease.

Ultrasound intima media thickness cut-off values for cranial and extracranial arteries in patients with suspected giant cell arteritis

Objective

To determine the optimal ultrasound (US) cut-off values for cranial and extracranial arteries intima media thickness (IMT) to discriminate between patients with and without giant cell arteritis (GCA).

Methods

Retrospective observational study including patients referred to an US fast-track clinic. All patients underwent bilateral US examination of the cranial and extracranial arteries including the IMT measurement. Clinical confirmation of GCA after 6 months was considered the gold standard for diagnosis. A receiver operating characteristic (ROC) analysis was performed to select the cut-off values on the basis of the best tradeoff values between sensitivity and specificity.

Results

A total of 157 patients were included, 47 (29.9%) with clinical confirmation of GCA after 6 months. 41 (87.2%) of patients with GCA had positive US findings (61.7% had cranial and 44.7% extracranial involvement). The best threshold IMT values were 0.44 mm for the common temporal artery; 0.34 mm for the frontal branch; 0.36 mm for the parietal branch; 1.1 mm for the carotid artery and 1 mm for the subclavian and axillary arteries. The areas under the ROC curves were greater for axillary arteries 0.996 (95% CI 0.991-1), for parietal branch 0.991 (95% CI 0.980-1), for subclavian 0.990 (95% CI 0.979-1), for frontal branch 0.989 (95% CI 0.976-1), for common temporal artery 0.984 (95% CI 0.959-1) and for common carotid arteries 0.977 (95% CI 0.961-0.993).

Conclusion

IMT cut-off values have been identified for each artery. These proposed IMT cut-off values may help to improve the diagnostic accuracy of US in clinical practice.

Unexplained chest pain in a patient with giant cell arteritis? Think aortic dissection

Giant cell arteritis (GCA) is the commonest of the large-vessel vasculitides. Aortic inflammation in patients with GCA was first described over 80 years ago, but it has only been possible to study this systematically following the development of more sophisticated imaging techniques such as computed tomography angiography, magnetic resonance angiography and positron emission tomography. Both NICE and the European League Against Rheumatism (EULAR) recognise that aortic dissection may complicate GCA but stop short of recommending routine imaging. We report a case that highlights a possible need for large-vessel imaging at the time of diagnosis and during follow-up to enable earlier recognition of aortitis and associated complications including dissection.

Temporal Artery Vascular Diseases

In the presence of temporal arteritis, clinicians often refer to the diagnosis of giant cell arteritis (GCA). However, differential diagnoses should also be evoked because other types of vascular diseases, vasculitis or not, may affect the temporal artery. Among vasculitis, Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis is probably the most common, and typically affects the peri-adventitial small vessel of the temporal artery and sometimes mimics giant cell arteritis, however, other symptoms are frequently associated and more specific of ANCA-associated vasculitis prompt a search for ANCA. The Immunoglobulin G4-related disease (IgG4-RD) can cause temporal arteritis as well. Some infections can also affect the temporal artery, primarily an infection caused by the varicella-zoster virus (VZV), which has an arterial tropism that may play a role in triggering giant cell arteritis. Drugs, mainly checkpoint inhibitors that are used to treat cancer, can also trigger giant cell arteritis. Furthermore, the temporal artery can be affected by diseases other than vasculitis such as atherosclerosis, calcyphilaxis, aneurysm, or arteriovenous fistula. In this review, these different diseases affecting the temporal artery are described.

Myocardial infarction during giant cell arteritis: A cohort study

BACKGROUND

Cardiovascular risk is increased in giant cell arteritis (GCA). We aimed to characterize myocardial infarction (MI) in a GCA cohort, and to compare the GCA and non-GCA population affected by MI.

METHODS

In patients with a biopsy-proven diagnosis of GCA between 1 January 2001 and 31 December 2016 in Côte D'Or (France), we identified patients with MI by crossing data from the territorial myocardial infarction registry (Observatoire des Infarctus de Côte d'Or) database. Five controls (non-GCA + MI) were paired with one case (GCA + MI) after matching for age, sex, cardiovascular risk factors and prior cardiovascular disease. MI were characterized as type 1 MI (T1MI), resulting from thrombus formation due to atherothrombotic disease, or type 2 MI (T2MI), due to a myocardial supply/demand mismatch. GCA-related MI was defined as MI occurring within 3 months of a GCA flare (before or after).

RESULTS

Among 251 biopsy-proven GCA patients, 13 MI cases were identified and paired with 65 controls. MI was GCA-related in 6/13 cases, accounting for 2.4% (6/251) of our cohort. T2MI was more frequently GCA-related than GCA-unrelated (80% vs. 16.7%, p = 0.080), and GCA diagnosis was the only identified triggering factor in 75% of GCA-related T2MI. GCA-unrelated MI were more frequently T1MI and occurred in patients who had received a higher cumulative dose of prednisone (p = 0.032). GCA was not associated with poorer one-year survival.

CONCLUSIONS

GCA-related MI are mainly T2MI probably caused by systemic inflammation rather than coronaritis. GCA-unrelated MI are predominantly T1MI associated with atherothrombotic coronary artery disease.

My Treatment Approach to Giant Cell Arteritis

Giant cell arteritis (GCA) is the most common primary systemic vasculitis in adults 50 years or older. Expanded use of advanced arterial imaging has assisted both in the diagnosis of GCA and recognition of disease subsets. Although glucocorticoids have been the mainstay of treatment for almost 7 decades, new therapeutic options have emerged. This review aims to provide the clinician with a pragmatic approach to evaluating and managing patients with GCA while also addressing recent diagnostic and therapeutic developments.

Associations among temporal and large artery abnormalities on vascular ultrasound in giant cell arteritis

Objectives: Giant cell arteritis (GCA) can manifest in cranial and/or extracranial arteries. We investigated the distribution of affected arteries on vascular ultrasound (VUS) among patients with new-onset or prior-onset GCA.Method: We retrospectively studied patients with either new-onset or prior-onset GCA and an abnormal VUS, from 2013 to 2017. Trained vascular technologists imaged the bilateral temporal arteries and carotid, axillary, and subclavian arteries. Vascular medicine physicians interpreted the images. Vasculitis-related abnormalities in individual vessels and their distribution (temporal artery, large artery, or both) were evaluated. Phi coefficients (φ) and Fisher's exact test were used to assess correlations among individual abnormal arteries.Results: Among 66 GCA patients, 28.8% had prior-onset GCA (median duration 17.8 months). Acute arteritis on VUS was observed in the majority of patients with both new-onset (72.3%) and prior-onset GCA (68.4%); the remainder had hyperechoic wall thickening without acute arteritis. Involvement of the temporal arteries only (45.5%) or large arteries only (34.8%) was more common than involvement of both (19.7%); this finding was similar in new-onset and prior-onset GCA. There were moderate positive correlations among temporal artery branches (φ = 0.51-0.58, p < 0.003) and among axillary and subclavian arteries (φ = 0.51-0.77, p < 0.003), and moderate negative correlations between abnormalities in the temporal and large arteries (φ = -0.46 to -0.58, p < 0.003).Conclusion: On VUS, vasculitis-related abnormalities in the temporal arteries only or large arteries only were more common than concurrent temporal and large artery abnormalities in patients with both new-onset GCA and prior-onset GCA.

Subclavian artery involvement in patients with giant cell arteritis: do we need a modified Halo Score?

OBJECTIVE

To assess whether adding the subclavian artery examination into the ultrasound (US) Southend Halo Score, as proposed in the modified Halo Score, improves the diagnostic accuracy of giant cell arteritis (GCA) and its relationship with systemic inflammation.

METHODS

Retrospective observational study of patients referred to a GCA fast track pathway (FTP) over a 1-year period. Patients underwent US exam of temporal and large vessel (LV) (carotid, subclavian, and axillary) arteries. The extent of inflammation was measured by the halo count, the Southend Halo Score, and the modified Halo Score. The gold standard for GCA diagnosis was clinical confirmation after 6-month follow-up.

RESULTS

Sixty-four patients were evaluated in the FTP, 17 (26.5%) had GCA. Subclavian artery involvement was present only in patients with GCA (29.4% versus 0%, p < 0.001). Overall, the three scores showed excellent diagnostic accuracy for GCA (ROC AUC 0.906, 0.930, and 0.928, respectively) and moderate correlations with acute phase reactants (0.35-0.51, p < 0.01). Only the modified Halo Score correlated with markers of inflammation in patients with LV involvement.

CONCLUSIONS

The inclusion of subclavian artery examination in the modified Halo Score does not improve the diagnostic accuracy of GCA. Nevertheless, it correlates better with markers of systemic inflammation in LV-GCA. Key Points • Adding the subclavian artery examination into the Southend Halo Score, as proposed in the modified Halo Score, does not improve the diagnostic accuracy of GCA. • However, the extent of vascular inflammation as quantified by the modified Halo Score correlates better with markers of systemic inflammation in the large vessel (LV) GCA subgroup of patients. • Although the diagnostic value of adding subclavian arteries to the current recommended US examination of GCA is limited, it may have a role in monitoring disease activity as it correlates with the general burden of inflammation in LV GCA. These findings need to be confirmed in additional populations and larger prospective studies.

Pathogenesis of Giant Cell Arteritis and Takayasu Arteritis-Similarities and Differences

PURPOSE OF REVIEW

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are auto-inflammatory and autoimmune diseases with a highly selective tissue tropism for medium and large arteries. In both diseases, CD4⁺ T cells and macrophages form granulomatous lesions within the arterial wall, a tissue site normally protected by immune privilege. Vascular lesions can be accompanied by an extravascular component, typically an intense hepatic acute phase response that produces well-known laboratory abnormalities, e.g., elevated ESR and CRP. It is unclear whether GCA and TAK lie on a spectrum of disease or whether they represent fundamentally different disease processes.

RECENT FINDINGS

GCA and TAK share many clinical features, but there are substantial differences in genetics, epidemiology, disease mechanisms, response to treatment, and treatment complications that give rise to different disease trajectories. A significant difference lies in the composition of the wall-infiltrating immune cell compartment, which in TAK includes a significant population of CD8⁺ T cells as well as natural killer cells, specifying disparate disease effector pathways mediating tissue damage and vessel wall remodeling. Despite the similarities in tissue tropism and histomorphology, GCA and TAK are two distinct vasculitides that rely on separate disease mechanisms and require disease-specific approaches in diagnosis and management.

Early variation of ultrasound halo sign with treatment and relation with clinical features in patients with giant cell arteritis

Objectives

To compare the ultrasound characteristics with clinical features, final diagnosis and outcome; and to evaluate the halo size following glucocorticoid treatment in patients with newly diagnosed GCA.

Methods

Patients with suspected GCA, recruited from an international cohort, had an ultrasound of temporal (TA) and axillary (AX) arteries performed within 7 days of commencing glucocorticoids. We compared differences in clinical features at disease presentation, after 2 weeks and after 6 months, according to the presence or absence of halo sign. We undertook a cross-sectional analysis of the differences in halo thickness using Pearson’s correlation coefficient (r) and Analysis of Variance (ANOVA).

Results

A total of 345 patients with 6 months follow-up data were included; 226 (65.5%) had a diagnosis of GCA. Jaw claudication and visual symptoms were more frequent in patients with halo sign (P =0.018 and P =0.003, respectively). Physical examination abnormalities were significantly associated with the presence of ipsilateral halo (P &lt;0.05). Stenosis or occlusion on ultrasound failed to contribute to the diagnosis of GCA. During 7 days of glucocorticoid treatment, there was a consistent reduction in halo size in the TA (maximum halo size per patient: r=−0.30, P =0.001; and all halos r=−0.23, P &lt;0.001), but not in the AX (P &gt;0.05). However, the presence of halo at baseline failed to predict future ischaemic events occurring during follow-up.

Conclusion

In newly diagnosed GCA, TA halo is associated with the presence of ischaemic features and its size decreases following glucocorticoid treatment, supporting its early use as a marker of disease activity, in addition to its diagnostic role.

18F-Fluorodeoxyglucose PET/Computed Tomography in the Diagnosis and Monitoring of Giant Cell Arteritis

18F-Fluorodeoxyglucose (FDG) PET/computed tomography (CT) is a highly accurate diagnostic tool for large vessel vasculitis (LVV) and is one of the recommended imaging modalities for confirmation of the diagnosis. This article focuses on the role of FDG-PET/CT in LVV diagnosis and disease monitoring, mainly focusing on giant cell arteritis; in particular, the diagnostic accuracy, diagnostic criteria, the potential pitfalls in the interpretation of large vessel FDG uptake, and the clinical indication compared with other imaging modalities are discussed.

Large-vessel Giant Cell Arteritis: A Rare Cause of Acute Upper Limb Ischemia – Case Presentation and Review of the Literature

Introduction: Acute upper extremity ischemia is an uncommon vascular emergency due to a relatively rich collateral network and low workload of the upper limb. Its consequences depend on the site and etiology of the arterial occlusion.

Case presentation: Aiming to emphasize the emerging role of Doppler ultrasound in the diagnosis of acute upper limb ischemia, we report the case of a 70-year-old female, with severe left arm resting pain and digital cyanosis. Due to the patient’s age and the presence of cardiovascular risk factors, cardioembolic or thrombotic arterial occlusion would have been the most likely diagnosis in this case, but the color Doppler ultrasound revealed severe left axillary arterial stenosis with hypoechoic wall swelling, being highly suggestive for arteritis. Temporal artery biopsy was performed, which confirmed giant cell arteritis. An excellent clinical response was obtained after initiation of treatment.

Conclusion: In acute upper limb ischemia, color duplex ultrasound provides quick information about the etiology and localization of arterial lesions, offering characteristic findings in case of large-vessel giant cell arteritis.

Diagnostic accuracy of ultrasound for detecting large-vessel giant cell arteritis using FDG PET/CT as the reference

Objectives

The diagnostic accuracy of axillary artery US in the diagnosis of large-vessel (LV)-GCA using 18F-fluorodeoxyglucose (FDG) PET/CT as reference standard was prospectively evaluated in GCA-suspected patients. As an exploratory analysis, the diagnostic accuracy of cranial artery FDG PET/CT was evaluated.

Methods

Briefly, the inclusion criteria were age ≥50 years, raised inflammatory markers and potential GCA symptoms. Patients in immunosuppressive therapy or with a previous diagnosis of GCA or PMR were excluded. Examinations were performed pre-treatment. LV-GCA reference diagnosis was a clinical diagnosis of GCA and PET-proven LV inflammation. GCA patients fulfilling ACR criteria were considered as cranial-GCA (c-GCA). Patients without GCA were considered controls. Receiver operating characteristic curve analysis of the US-measured axillary intima-media thickness was performed. FDG uptake in temporal, maxillary and vertebral arteries was also assessed.

Results

Forty-six patients were diagnosed with LV-GCA, 10 with isolated c-GCA, and in 34 patients GCA was dismissed. Axillary US yielded a sensitivity of 76% and a specificity of 100% for LV-GCA. An axillary intima-media thickness cut-off of 1.0 mm yielded a sensitivity of 74% and a specificity of 92%. Adding LV US to temporal assessment increased sensitivity from 71% to 97% (all GCA patients). Cranial artery PET showed a diagnostic sensitivity of 78% and specificity of 100% for c-GCA.

Conclusion

Axillary artery US shows high accuracy for the LV-GCA diagnosis. Building upon the recent EULAR recommendations, we propose a diagnostic algorithm with US as the first-line confirmatory test, not only in c-GCA-suspected patients, but in all patients suspected of GCA.

Magnetic resonance angiography versus 18F-fluorodeoxyglucose positron emission tomography in large vessel vasculitis

With advances in our understanding of the pathogenesis of large vessel vasculitides, we recognise the persistence of inflammation in large vessels, sometimes despite therapy to control clinical symptoms. Achieving an early diagnosis and establishing the extent of disease are important steps in improving our management of these diseases. Imaging is playing an increasing role in the assessment of these patients from diagnosis to prognosis. We review the current and potential role of two important and potentially complementary imaging techniques of magnetic resonance angiography and 18F-fluorodeoxyglucose positron emission tomography in the evaluation of patients with giant cell arteritis and Takayasu arteritis.

Systematic literature review informing the 2018 update of the EULAR recommendation for the management of large vessel vasculitis: focus on giant cell arteritis

Objectives

To analyse the current evidence for the management of large vessel vasculitis (LVV) to inform the 2018 update of the EULAR recommendations.

Methods

Two systematic literature reviews (SLRs) dealing with diagnosis/monitoring and treatment strategies for LVV, respectively, were performed. Medline, Embase and Cochrane databases were searched from inception to 31 December 2017. Evidence on imaging was excluded as recently published in dedicated EULAR recommendations. This paper focuses on the data relevant to giant cell arteritis (GCA).

Results

We identified 287 eligible articles (122 studies focused on diagnosis/monitoring, 165 on treatment). The implementation of a fast-track approach to diagnosis significantly lowers the risk of permanent visual loss compared with historical cohorts (level of evidence, LoE 2b). Reliable diagnostic or prognostic biomarkers for GCA are still not available (LoE 3b).The SLR confirms the efficacy of prompt initiation of glucocorticoids (GC). There is no high-quality evidence on the most appropriate starting dose, route of administration, tapering and duration of GC (LoE 4). Patients with GCA are at increased risk of dose-dependent GC-related adverse events (LoE 3b). The addition of methotrexate or tocilizumab reduces relapse rates and GC requirements (LoE 1b). There is no consistent evidence that initiating antiplatelet agents at diagnosis would prevent future ischaemic events (LoE 2a). There is little evidence to guide monitoring of patients with GCA.

Conclusions

Results from two SLRs identified novel evidence on the management of GCA to guide the 2018 update of the EULAR recommendations on the management of LVV.

Current and emerging therapies in large-vessel vasculitis

GCA shares many clinical features with PMR and Takayasu arteritis. The current mainstay of therapy for all three conditions is glucocorticoid therapy. Given the chronic, relapsing nature of these conditions and the morbidity associated with glucocorticoid therapy, there is a need for better treatment options to induce and sustain remission with fewer adverse effects. Conventional immunosuppressive treatments have been studied and have a modest effect. There is a keen interest in biologic therapies with studies showing the efficacy of IL-6 antagonists in PMR and GCA. Recently the first two randomized clinical trials in Takayasu arteritis have been completed. A major challenge for all of these conditions is the lack of standardized measures to assess disease activity. Long-term studies are needed to evaluate the impact of biologic therapies showing potential on important clinical outcomes such as vascular damage, cost-effectiveness and quality of life. The optimal duration of treatment also needs to be assessed.

Giant cell arteritis as unusual cause of critical arm ischemia

Giant cell arteritis is an inflammatory vasculopathy of unknown etiology that typically affects the carotid artery and its branches. Symptomatic involvement of upper extremity arteries is uncommon. We report a case of a 70-year-old woman with polymyalgia rheumatica who presented with critical arm ischemia, constitutional symptoms, and elevated erythrocyte sedimentation rate. Urgent revascularization by a carotid-brachial artery bypass was performed. Histopathologic evaluation of a specimen obtained intraoperatively from the occluded axillary artery confirmed the diagnosis, and corticosteroid therapy was initiated. Large-vessel vasculitis should be considered a rare differential diagnosis in occlusive disease of the upper extremity.

Large-vessel giant cell arteritis: diagnosis, monitoring and management

GCA is a chronic, idiopathic, granulomatous vasculitis of medium and large arteries. It comprises overlapping phenotypes including classic cranial arteritis and extra-cranial GCA, otherwise termed large-vessel GCA (LV-GCA). Vascular complications associated with LV-GCA may be due, in part, to delayed diagnosis, highlighting the importance of early identification and prompt initiation of effective therapy. Advancements in imaging techniques, including magnetic resonance angiography, CT angiography, PET and colour duplex ultrasonography, have led to improvements in the diagnosis of LV-GCA; however, the role imaging modalities play in the assessment of disease activity and long-term outcomes remains unclear. Glucocorticoids are the mainstay of therapy in LV-GCA, but their prolonged use is associated with multiple, sometimes serious, adverse effects. Recent data suggest that biologic therapies, such as tocilizumab, may be effective and safe steroid-sparing options for patients with GCA. However, data specifically evaluating the management of LV-GCA are limited.

Definitions and reliability assessment of elementary ultrasound lesions in giant cell arteritis: a study from the OMERACT Large Vessel Vasculitis Ultrasound Working Group

Objectives

To define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise.

Methods

Potential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise.

Results

Twenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The ‘halo’ and ‘compression’ signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the ‘halo’ sign and the ‘compression’ sign was excellent with inter-rater agreements of 91–99% and mean kappa values of 0.83–0.98 for both inter-rater and intra-rater reliabilities of all 25 experts.

Conclusions

The ‘halo’ and the ‘compression’ signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent.

Arterial lesions in giant cell arteritis: A longitudinal study

OBJECTIVES

To evaluate large-vessel (LV) abnormalities on serial imaging in patients with giant cell arteritis (GCA) and discern predictors of new lesions.

METHODS

Clinical and imaging data from patients with GCA (including subjects diagnosed by LV imaging) enrolled in a prospective, multicenter, longitudinal study and/or a randomized clinical trial were included. New arterial lesions were defined as a lesion in a previously unaffected artery.

RESULTS

The study included 187 patients with GCA, 146 (78%) female, mean (±SD) age at diagnosis 68.5 ± 8.5 years; 39% diagnosed by LV imaging. At least one arterial lesion was present in 123 (66%) on the first study. The most frequently affected arteries were subclavian (42%), axillary (32%), and thoracic aorta (20%). In 106 patients (57%) with serial imaging, new arterial lesions were noted in 41 patients (39%), all of whom had a baseline abnormality, over a mean (±SD) follow-up of 4.39 (2.22) years. New abnormalities were observed in 33% patients by year 2; clinical features of active disease were present at only 50% of these cases. There were no differences in age, sex, temporal artery biopsy positivity, or disease activity in patients with or without new lesions.

CONCLUSIONS

In this cohort of patients with GCA, LV abnormalities on first imaging were common. Development of new arterial lesions occurred in patients with arterial abnormalities at first imaging, often in the absence of symptoms of active disease. Arterial imaging should be considered in all patients with GCA at diagnosis and serial imaging at least in patients with baseline abnormalities.

Takayasu arteritis and giant cell arteritis: are they a spectrum of the same disease?

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are forms of large-vessel vasculitides that affect the aorta and its branches. There is ongoing debate about whether they are within a spectrum of the same disease or different diseases. Shared commonalities include clinical features, evidence of systemic inflammation, granulomatous inflammation on biopsy, role of T-helper (Th)-1 and Th17 in the pathogenesis, and, abnormalities of the aorta and its branches on imaging. However, there are also several differences in the geographic distribution, genetics, inflammatory cells and responses to treatment. This review highlights the similarities and differences in the epidemiology, pathogenesis, clinical manifestations, imaging findings and treatment responses in these conditions. Current data supports that they are two distinct conditions despite the numerous similarities.

Recent Advances in Giant Cell Arteritis

PURPOSE OF REVIEW

Giant cell arteritis (GCA) is the most common systemic vasculitis. GCA is categorized as a granulomatous vasculitis of large and medium size vessels. Majority of the symptoms and signs of GCA result from involvement of the aorta and its branches intra- and extracranial. Temporal artery biopsy continues to be the cardinal diagnostic procedure despite new imaging modalities for diagnosing GCA with cranial involvement. Great advances in awareness have led to improvement in preventing irreversible vision loss due to early diagnosis.

RECENT FINDINGS

The cause of GCA has not been elucidated but major progress has been made in the knowledge of its pathogenesis leading to new therapeutic targets, particularly inhibition of interleukin 6. IL 6 plays a key role in the regulation of TH17/Tregs imbalance in GCA and appears to correlate with clinical disease activity in GCA. All of this has led to the first FDA (food and drug administration) approved treatment for GCA, Tocilizumab. Abatacept and Ustekinumab are promising targets for therapy in LVV but still need further research. This paper is a review of the recent progress in the understanding of GCA pathogenesis, diagnosis, treatment, and prognosis.

Acute Brachial Radiculoplexopathy and Giant Cell Arteritis

INTRODUCTION

Giant cell arteritis (GCA), a vasculitis involving large-sized and medium-sized vessels (which most commonly involves temporal arteries), is easily recognized in older patients presenting with headache, scalp tenderness, and raised inflammatory markers. Neurological complications (either central or peripheral) are classically described in GCA.

CASE REPORT

We report the case of an 85-year-old woman with bilateral acute brachial radiculoplexopathy, a rare neurological complication of GCA. She also presented right oculomotor palsy (with ptosis) and raised inflammatory markers, but she did not complain of the other classic cranial symptoms of the disease. We compare this case with 16 similar cases reported in the medical literature.

CONCLUSIONS

In assessing a patient over 50 years of age with unexplained (unilateral or bilateral) brachial radiculoplexopathy (especially if C5-C6 nerve roots are affected) and elevated inflammatory markers, we would recommend specific enquiries with regard to the manifestations of GCA. The purpose is to reduce the risk of missing the wider spectrum of this condition and minimize the subsequent risk for disability of this treatable disease.

Ultrasound cut-off values for intima-media thickness of temporal, facial and axillary arteries in giant cell arteritis

Objective

To evaluate the intima-media thickness (IMT) of arteries involved in GCA for determining cut-off values.

Methods

Forty newly diagnosed GCA patients in a fast-track GCA clinic and 40 age- and sex-matched controls were included. IMT measurement was performed at or within 24 h after diagnosis. The common superficial temporal arteries with their frontal and parietal branches and the facial arteries were bilaterally examined with a 10-22 MHz probe and the axillary artery with a 6-18 MHz probe. Receiver operating characteristics analysis was performed for estimating cut-off values.

Results

The mean age was 72 years (s.d. 9) and 68% were females. In the control group, IMT was 0.23 mm (s.d. 0.04), 0.19 mm (s.d. 0.03), 0.20 mm (s.d. 0.03), 0.24 mm (s.d. 0.05) and 0.59 mm (s.d. 0.10) for the common superficial temporal arteries, the frontal and parietal branches, the facial arteries and the axillary arteries, respectively. In vasculitic segments of GCA patients, IMT was 0.65 mm (s.d. 0.18), 0.54 mm (s.d. 0.18), 0.50 mm (s.d. 0.17), 0.53 mm (s.d. 0.16) and 1.7 mm (s.d. 0.41), respectively. Cut-off values are 0.42, 0.34, 0.29, 0.37 and 1.0 mm, respectively, with 100% sensitivities and specificities for common superficial temporal arteries, for frontal branches and for axillary arteries and sensitivities of 97.2 and 87.5% and specificities of 98.7 and 98.8% for parietal branches and facial arteries, respectively. The intraclass correlation coefficient was between 0.87 and 0.98.

Conclusion

IMT measurement can correctly distinguish vasculitic from normal arteries in suspected GCA.

A Retrospective Study of Chinese Patients With Giant Cell Arteritis (GCA): Clinical Features and Factors Associated With Severe Ischemic Manifestations

A retrospective study was performed on 70 giant cell arteritis (GCA) patients in Peking Union Medical College Hospital (PUMCH). The aim of this study was to describe the clinical features of these Chinese GCA patients and explore the possible associated factors for severe ischemic manifestations. Medical charts of all patients were reviewed, and the demographic, clinical, and laboratory data were analyzed. The mean age at disease onset was 65.2 years old, and the ratio of male to female was 1:1. Fever and headache were most prominent symptoms at onset, which occurred in 51.4% and 30.0% of patients, respectively. Common manifestations at diagnosis were constitutional symptoms (85.7%), headache (68.8%), visual impairment (38.6%), jaw claudication (30%), scalp tenderness (30%), and concurrent polymyalgia rheumatic (27.1%). No significant difference in clinical manifestations between genders was observed. Comparisons between patients with and without severe ischemic manifestations including jaw claudication, permanent visual loss, or cerebrovascular accident had shown that fever and asthenia were significantly less frequent in patients with severe ischemic manifestations (P = 0.006 and 0.023, respectively), and the mean value of erythrocyte sedimentation rate (ESR) was significantly lower in patients with severe ischemic manifestations than patients without (P = 0.001). History of smoking was more frequent in patients with severe ischemic manifestations (P = 0.038). This is the largest group of GCA patients from China so far. When compared our data with patients reported in the literature, this series of GCA patients were younger and without female predominance. The clinical manifestations of patients in this report were similar to other studies except for a higher prevalence of constitutional symptoms. The results of this study indicated that lower systemic inflammatory response and the history of smoking might be associated with severe ischemic damages.

Imaging in systemic vasculitis

PURPOSE OF REVIEW

Imaging is becoming a relevant tool for the assessment of patients with systemic vasculitis. This review focuses on recently generated data with potential clinical impact in the diagnosis, evaluation of disease extent and management of systemic vasculitis.

RECENT FINDINGS

Temporal artery examination by color duplex ultrasonography (CDUS) is a valuable approach to the diagnosis of giant-cell arteritis. Evaluation of additional arteries may increase its diagnostic performance. However, CDUS-specific findings may not be detected in arteries with early inflammation and CDUS-guidance of temporal artery biopsy does not seem to significantly increase its diagnostic yield. Large-vessel involvement detected by computed tomography angiography occurs in two out of three of patients with giant-cell arteritis at diagnosis. Furthermore, significant ascending aortic dilatation can be observed in one out of three of patients after long-term follow-up. Objective cut-offs for detecting large-vessel inflammation by positron emission tomography (PET) are trying to be established through prospective studies. PET may also contribute to the assessment of disease extent in patients with ANCA-associated vasculitis or Behçet's disease.

SUMMARY

Data generated by existing and emerging imaging techniques are expected to have a major impact in the diagnosis, appraisal of disease extent, evaluation of disease activity and response to treatment in patients with systemic vasculitis.

Biologic therapy in ANCA-negative vasculitis

Standard therapeutic schemes for vasculitis are usually associated with numerous side effects and uneven clinical response. However, recent advances in understanding of the pathogenesis of these systemic diseases have resulted in the development of a group of biologic agents potentially useful in patients with vasculitis. Thus, anti-tumor necrosis factor-α drugs may be effective in patients with refractory Kawasaki disease but have failed to do so in giant cell arteritis, and their role in Takayasu arteritis is yet unclear. Preliminary reports on the use of the anti-IL6-receptor antibody, tocilizumab, in large-vessel vasculitis have been encouraging. Interferon alpha has showed positive results in hepatitis B virus-associated polyarteritis nodosa, and hepatitis C virus-induced cryoglobulinemia. Early experience with rituximab in several types of vasculitis has been quite promising, but must be confirmed in ongoing randomized clinical trials. The development of new biologic targeted therapies will probably open a hopeful future for patients with vasculitis.

Clinical diagnosis and management of large vessel vasculitis: giant cell arteritis

Large vessel vasculitis (LVV) covers a spectrum of primary vasculitides predominantly affecting the aorta and its major branches. The two main subtypes are giant cell arteritis (GCA) and Takayasu arteritis (TA). Less commonly LVV occurs in various other diseases. Clinical manifestations result from vascular stenosis, occlusion, and dilation, sometimes complicated by aneurysm rupture or dissection. Occasionally LVV is discovered unexpectedly on pathological examination of a resected aortic aneurysm. Clinical evaluation is often unreliable in determining disease activity. Moreover, the diagnostic tools are imperfect. Acute phase reactants can be normal at presentation and available imaging modalities are more reliable in delineating vascular anatomy than in providing reliable information on degree of vascular inflammation. Glucocorticoids are the mainstay of therapy of LVV. Patients may develop predictable adverse effects from long-term glucocorticoid use. Several steroid-sparing agents have also shown some promise and are currently in use. Endovascular revascularization procedures and open surgical treatment for aneurysms and dissections are sometimes necessary, but results are not always favorable and relapses are common. This article, the first in a series of two, will be devoted to GCA and isolated (idiopathic) aortitis, while TA will be covered in detail in the next article.

Impact of cranial and axillary/subclavian artery involvement by color duplex sonography on response to treatment in giant cell arteritis

OBJECTIVE

Color duplex sonography (CDS) today is broadly used in the diagnostic workup of patients with suspected cranial or extracranial giant cell arteritis (GCA). This study aimed to determine the prognostic impact of the disease pattern assessed by CDS on the treatment response in GCA.

METHODS

This was a retrospective, longitudinal follow-up study of 43 patients who were diagnosed with GCA at our institution between 2002 and 2010. All patients underwent CDS of the temporal and subclavian/axillary arteries at baseline and were observed for at least 6 months. Vasculitis was sonographically characterized by a circumferential, hypoechogenic wall thickening. According to the CDS findings, patients were categorized into patients with involvement of the subclavian/axillary arteries only (group A1, n = 17), patients with involvement of both the subclavian/axillary arteries and the temporal arteries (group A2, n = 9), and patients with isolated cranial GCA (group B, n = 17). Data on recurrences, corticosteroid doses, and steroid-sparing agents were extracted from the medical records. Treatment response over time was analyzed by Kaplan-Meier curves with log-rank testing.

RESULTS

The mean follow-up time was 25.4 months and did not differ between groups (P = .4). Patients in group A1 were significantly younger than patients in groups A2 and B (P < .01). The interval between symptom onset and diagnosis was significantly longer in groups A1 and A2 compared with group B (P < .01). The number of recurrences per month was significantly higher in group A2 compared with group A1 and group B (A1, 0.07; A2, 0.13; B, 0.03; P < .01). Whereas there were no significant differences in the mean time until a daily prednisolone dose <10 mg was reached, patients in group A2 more frequently required steroid-sparing agents (A1, 24%; A2, 56%; B, 24%; P = .04).

CONCLUSIONS

Extensive vascular involvement of both the temporal and subclavian/axillary arteries, as depicted by CDS, may be associated with a poor treatment response in GCA.

Effect of glucocorticoid treatment on computed tomography angiography detected large-vessel inflammation in giant-cell arteritis. A prospective, longitudinal study

Computed tomography angiography (CTA) detects signs of large-vessel vasculitis (LVV) in about 67.5% of patients with giant-cell arteritis (GCA) at the time of diagnosis and early aortic dilatation in 15%. The outcome of CTA-findings of LVV upon glucocorticoid treatment has not been prospectively evaluated. The aim of our study was to prospectively assess glucocorticoid-induced changes in CTA findings of LVV in patients with GCA. Forty biopsy-proven GCA patients evaluated by CTA at diagnosis were prospectively followed and scheduled a new CTA approximately after 1 year of treatment. Vessel wall thickening, diameter, and contrast enhancement of the aorta and its tributaries were evaluated. Results were compared to those obtained at the time of diagnosis. CTA was repeated to 35 patients after a median follow-up of 13.5 months (IQ25-75% 12.4-15.8). Arterial wall thickening was still present in 17 patients (68% of the patients who initially had LVV). The number of affected segments and wall thickness at various aortic segments significantly decreased and no patients developed new lesions, new aortic dilation or increase in previous dilation. Contrast enhancement disappeared in 15 (93.75%) of 16 patients in whom this finding could be assessed. Signs of LVV improve with treatment. While contrast enhancement resolves in the majority of patients, vessel wall thickening persists in two thirds. However, the number of affected aortic segments as well as aortic wall thickness significantly decreases. Longer follow-up is necessary to determine the clinical significance of persisting wall thickening and its relationship with relapses or subsequent development of aortic dilatation or large-vessel stenoses.