The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study

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.

Vascular Ultrasound for Giant Cell Arteritis: Establishing a Protocol Using Vascular Sonographers in a Fast-Track Clinic in the United States

OBJECTIVE

We developed a fast-track clinic (FTC) to expedite the evaluation of patients suspected of having giant cell arteritis (GCA) using vascular ultrasound. Though FTCs have demonstrated efficacy in Europe, no protocolized clinic in the United States has been developed. This study introduces a new FTC model unique to the United States, using vascular sonographers, and describes the protocols used to develop reliable findings. We evaluate clinical outcomes using vascular ultrasound and temporal artery biopsy (TAB).

METHODS

A retrospective review included all subjects referred to the University of Washington FTC aged 50 years old or older who received both ultrasound and TAB between November 2017 and November 2019. Ultrasound was performed by a vascular sonographer trained in GCA detection. Ultrasound results were read by a vascular surgeon and reviewed by four rheumatologists certified in musculoskeletal ultrasound who had completed a course in vascular ultrasound use in GCA and large-vessel vasculitis.

RESULTS

A total of 43 subjects underwent both vascular ultrasound and TAB. Six subjects had both positive ultrasound and TAB results. There were also seven positive ultrasound results in patients with negative TAB results, most due to detection of large-vessel GCA (LV-GCA). All 29 subjects with negative ultrasound results had negative TAB results.

CONCLUSION

This is the first study in the United States to demonstrate a reliable FTC protocol using vascular sonographers. This protocol demonstrated good agreement between ultrasound and TAB and allowed for the detection of additional cases of LV-GCA by vascular ultrasound. Vascular ultrasound improved the rate of GCA diagnosis primarily by detecting additional cases of LV-GCA.

Colour Doppler ultrasound and the giant cell arteritis probability score for the diagnosis of giant cell arteritis: a Canadian single-centre experience

Objectives

The aim was to compare the accuracy of colour Doppler ultrasonography (CDUS) and temporal artery biopsy (TAB) to establish the final diagnosis of GCA and to determine how the GCA probability score (GCAPS) performs as a risk stratification tool.

Methods

Descriptive statistics were performed on a retrospective cohort of patients referred to our vasculitis referral centre between 1 July 2017 and 1 October 2020 for suspected GCA. CDUS, TAB, centre-specific TAB (vasculitis centre vs referring hospitals) and GCAPS were compared against the final diagnosis of GCA as determined by a GCA expert; CDUS was also compared with TAB results.

Results

Data from 198 patients were included: 60 patients with GCA and 138 patients without GCA. Sixty-two patients had a TAB. Using the final diagnosis by a GCA expert as a reference, the sensitivity, specificity, positive predictive value and negative predictive value were 93.3%, 98.5%, 96.6% and 97.1% for CDUS and 69.2%, 100%, 100% and 81.8% for TAB, respectively. The false-negative rate was 6.7% for CDUS and 30.8% for TAB. False-negative TAB mostly occurred when performed in referring hospitals (57.1%) as opposed to our vasculitis centre (21.1%). With a cut-off at 9.5 points, sensitivity for GCAPS was 98.3% and specificity 74.3%.

Conclusion

CDUS of the temporal and axillary arteries showed a high sensitivity and specificity and helped to diagnose GCA in patients with negative TAB. We validated that GCAPS is a useful clinical tool, with a score of <9.5 making the diagnosis of GCA improbable.

Diagnostic accuracy of vascular ultrasound in patients with suspected giant cell arteritis (EUREKA): a prospective, multicentre, non-interventional, cohort study

BACKGROUND

Temporal artery biopsy is considered the diagnostic gold standard for giant cell arteritis, despite approximately 39% of patients who are negative for the condition by biopsy subsequently being given a clinical diagnosis of giant cell arteritis. We aimed to assess the diagnostic accuracy of ultrasound examination in patients with suspected giant cell arteritis.

METHODS

In this prospective, multicentre, non-interventional, cohort study (evaluation of ultrasound's role in patients suspected of having extracranial and cranial giant cell arteritis; EUREKA), we consecutively recruited patients aged 50 years or older, with clinically suspected giant cell arteritis from three Danish hospitals (South West Jutland Hospital in Esbjerg, Silkeborg Regional Hospital, and Rigshospitalet, Glostrup). Participants had a bilateral ultrasound of the temporal, facial, common carotid, and axillary arteries. Ultrasounds were done by ultrasonographers who were systematically trained in vascular ultrasound using appropriate equipment and settings. Participants then had a temporal artery biopsy within 7 days of initiation of corticosteroid treatment. A blinded ultrasound expert assessed all ultrasound images. Ultrasound vasculitis was defined in cranial arteries as a homogeneous, hypoechoic, intimamedia complex thickness and a positive compression sign and as a homogeneous intimamedia complex of 1 mm in thickness or wider in the axillary arteries and of 1·5 mm thickness or wider in the common carotid artery. Participants were followed up at 6 months. During this 6 month period, clinicians were able to collect data from all clinical examinations to enable a full clinical diagnosis at 6 months. Clinical diagnosis was based on the expert opinion of the treating rheumatologist. The diagnostic criterion standard was diagnosis confirmed after 6 months of follow-up. We used logistic regression analyses to calculate the odds ratio and 95% CI of ultrasound as a predictor for giant cell arteritis.

FINDINGS

Between April 1, 2014, and July 31, 2017, 118 patients were screened for inclusion, of whom 106 had both ultrasound examinations and an eligible temporal artery biopsy and were included in the intention-to-diagnose population. The mean age was 72·7 years (SD 7·9), 63 (59%) participants were women, and 43 (41%) were men. Temporal artery biopsy was positive in 46 (43%) of 106 patients, and 62 (58%) of 106 patients had a clinically confirmed diagnosis of giant cell arteritis at 6 months (temporal artery biopsy sensitivity 74% [95% CI 62-84], specificity 100% [95% CI 92-100]). Cranial artery ultrasound was positive in all patients who had a positive temporal artery biopsy, and seven (58%) of 12 patients who were positive by ultrasound and negative by temporal artery biopsy were confirmed to have large-vessel giant cell arteritis via other imaging methods. The sensitivity of ultrasound diagnosis of giant cell arteritis was 94% (84-98) and specificity was 84% (70-93). Logistic regression analysis confirmed that ultrasound was the strongest baseline predictor for a clinically confirmed diagnosis of giant cell arteritis at 6 months (crude odds ratio 76·6 [95% CI 21·0-280·0]; adjusted for sex and age 141·0 [27·0-743·0]).

INTERPRETATION

Vascular ultrasound might effectively replace temporal artery biopsy as a first-line diagnostic method in patients suspected of having giant cell arteritis when done by systematically trained ultrasonographers using appropriate equipment and settings.

FUNDING

The Institute for Regional Research at Hospital of Southwest Jutland, Esbjerg, Denmark.

ACR Appropriateness Criteria® Noncerebral Vasculitis

Noncerebral vasculitis is a wide-range noninfectious inflammatory disorder affecting the vessels. Vasculitides have been categorized based on the vessel size, such as large-vessel vasculitis, medium-vessel vasculitis, and small-vessel vasculitis. In this document, we cover large-vessel vasculitis and medium-vessel vasculitis. Due to the challenges of vessel biopsy, imaging plays a crucial role in diagnosing this entity. While CTA and MRA can both provide anatomical details of the vessel wall, including wall thickness and enhancement in large-vessel vasculitis, FDG-PET/CT can show functional assessment based on the glycolytic activity of inflammatory cells in the inflamed vessels. Given the size of the vessel in medium-vessel vasculitis, invasive arteriography is still a choice for imaging. However, high-resolution CTA images can depict small-caliber aneurysms, and thus can be utilized in the diagnosis of medium-vessel vasculitis. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Functionally Heterogenous Macrophage Subsets in the Pathogenesis of Giant Cell Arteritis: Novel Targets for Disease Monitoring and Treatment

Giant cell arteritis (GCA) is a granulomatous large-vessel vasculitis that affects adults above 50 years of age. In GCA, circulating monocytes are recruited to the inflamed arteries. With cues from the vascular microenvironment, they differentiate into macrophages and play important roles in the pathogenesis of GCA via pro-inflammatory cytokine production and vascular remodeling. However, a deeper understanding of macrophage heterogeneity in GCA pathogenesis is needed to assist the development of novel diagnostic tools and targeted therapies. Here, we review the current knowledge on macrophage heterogeneity and diverse functions of macrophage subsets in the pathogenesis of GCA. We next discuss the possibility to exploit their heterogeneity as a source of novel biomarkers and as targets for nuclear imaging. Finally, we discuss novel macrophage-targeted therapies and future directions for targeting these cells in GCA.

Validation of a multimodal algorithm for diagnosing giant cell arteritis with imaging

PURPOSE

The purpose of this study was to identify which combination of imaging modalities should be used to obtain the best diagnostic performance for the non-invasive diagnosis of giant cell arteritis (GCA).

MATERIALS AND METHODS

This IRB-approved prospective single-center study enrolled participants presenting with a suspected diagnosis of GCA from December 2014 to October 2017. Participants underwent high-resolution 3T magnetic resonance imaging (MRI), temporal and extra-cranial arteries ultrasound and retinal angiography (RA), prior to temporal artery biopsy (TAB). Diagnostic accuracy of each imaging modality alone, then a combination of several imaging modalities, was evaluated. Several algorithms were constructed to test optimal combinations using McNemar test.

RESULTS

Forty-five participants (24 women, 21 men) with mean age of 75.4 ± 16 (SD) years (range: 59-94 years) were enrolled; of these 43/45 (96%) had ophthalmological symptoms. Diagnosis of GCA was confirmed in 25/45 (56%) patients. Sensitivity and specificity of MRI, ultrasound and RA alone were 100% (25/25; 95% CI: 86-100) and 86% (19/22; 95% CI: 65-97), 88% (22/25; 95% CI: 69-97) and 84% (16/19; 95% CI: 60-97), 94% (15/16; 95% CI: 70-100) and 74% (14/19; 95% CI: 49-91), respectively. Sensitivity, specificity, positive predictive and negative predictive values ranged from 95 to 100% (95% CI: 77-100), 67 to 100% (95% CI: 38-100), 81 to 100% (95% CI: 61-100) and 91 to 100% (95% CI: 59-100) when combining several imaging tests, respectively. The diagnostic algorithm with the overall best diagnostic performance was the one starting with MRI, followed either by ultrasound or RA, yielding 100% sensitivity (22/22; 95% CI: 85-100%) 100% (15/15; 95% CI: 78-100) and 100% accuracy (37/37; 95% CI: 91-100).

CONCLUSION

The use of MRI as the first imaging examination followed by either ultrasound or RA reaches high degrees of performance for the diagnosis of GCA and is recommended in daily practice.

Contextualizing temporal arterial magnetic resonance angiography in the diagnosis of giant cell arteritis: a retrospective cohort study

OBJECTIVES

Imaging modalities have become common in evaluating patients for a possible diagnosis of GCA. This study seeks to contextualize how temporal arterial magnetic resonance angiography (TA-MRA) can be used in facilitating the diagnosis of GCA.

METHODS

A retrospective cohort study was performed on patients who had been previously referred to a rheumatologist for evaluation of possible GCA in Hamilton, Ontario, Canada. Data including clinical features, inflammatory markers, imaging, and biopsy results were extracted. Multivariable logistic regression model to predict the diagnosis of GCA. Using these models, the utility of TA-MRA in series with or in parallel to clinical evaluation was demonstrated across the cohort as well as in subgroups defined by biopsy and imaging status.

RESULTS

In total 268 patients had complete data. Those diagnosed with biopsy- and/or imaging-positive GCA were more likely to demonstrate classic features including jaw claudication and vision loss. Clinical multivariable modelling allowed for fair discriminability [receiver operating characteristic (ROC) 0.759, 95% CI: 0.703, 0.815] for diagnosing GCA; there was excellent discriminability in facilitating the diagnosis of biopsy-positive GCA (ROC 0.949, 0.898-1.000). When used in those with a pre-test probability of 50% or higher, TA-MRA had a positive predictive value of 93.0%; in those with a pre-test probability of 25% or less TA-MRA had a negative predictive value of 89.5%.

CONCLUSION

In those with high disease probability, TA-MRA can effectively rule in disease (and replace temporal artery biopsy). In those with low to medium probability, TA-MRA can help rule out the disease, but this continues to be a challenging diagnostic population.

Vascular ultrasound for the diagnosis of giant cell arteritis: a reliability and agreement study based on a standardised training programme

Objective

To evaluate the impact of a standardised training programme including equipment adjustment for experienced musculoskeletal ultrasonographers without previous experience in vascular ultrasound (US) on the reliability of US in the diagnosis of giant cell arteritis (GCA).

Methods

In this prospective, non-interventional observational cohort study, patients suspected of GCA were evaluated by US by one of five rheumatologists with long-standing experience in musculoskeletal US (>8 years), trained using a standardised training programme including equipment adjustment. Images of cranial and large vessels were subsequently evaluated first by the performing ultrasonographer and thereafter by a blinded external expert (gold standard).

Results

In three Danish centres, 112 patients suspected of GCA were included. According to the external expert, vasculitis changes were seen in 66 patients, in 45 of them with only cranial involvement, in 14 with both cranial and large vessel involvement, while in seven patients isolated large vessel vasculitis was found. The reliability was excellent between the local ultrasonographer and the US expert for the overall GCA diagnosis regarding the diagnosis of cranial and for large vessel GCA, with an interobserver agreement of 95–96%, mean kappa values of 0.88–0.92 (95% CI 0.78 to 0.99). Excellent reliability (mean kappa 0.86–1.00) was also found for the US examination of the individual arteries (temporal, facial, common carotid and axillary).

Conclusion

The US training programme resulted in excellent agreement between trainees and an expert in patients suspected of GCA and may thus be applicable for implementation of vascular US in clinical practice.

Attitudes of Canadian Plastic Surgeons on Temporal Artery Biopsy in Giant Cell Arteritis Management

Temporal artery biopsies (TAB) rarely impact management of patients with suspected giant cell arteritis and carry complications. We sought plastic surgeons’ perspectives on this procedure’s risks and benefits.

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.

Role of the halo sign in the assessment of giant cell arteritis: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis aimed to evaluate the diagnostic value of the halo sign in the assessment of GCA.

METHODS

A systematic literature review was performed using MEDLINE, EMBASE and Cochrane central register databases up to August 2020. Studies informing on the sensitivity and specificity of the US halo sign for GCA (index test) were selected. Studies with a minimum of five participants were included. Study articles using clinical criteria, imaging such as PET-CT and/or temporal artery biopsy (TAB) as the reference standards were selected. Meta-analysis was conducted with a bivariate model.

RESULTS

The initial search yielded 4023 studies. Twenty-three studies (patients n = 2711) met the inclusion criteria. Prospective (11 studies) and retrospective (12 studies) studies in academic and non-academic centres were included. Using clinical diagnosis as the standard (18 studies) yielded a pooled sensitivity of 67% (95% CI: 51, 80) and a specificity of 95% (95% CI: 89, 98%). This gave a positive and negative likelihood ratio for the diagnosis of GCA of 14.2 (95% CI: 5.7, 35.5) and 0.375 (95% CI: 0.22, 0.54), respectively. Using TAB as the standard (15 studies) yielded a pooled sensitivity of 63% (95% CI: 50, 75) and a specificity of 90% (95% CI: 81, 95).

CONCLUSION

The US halo sign is a sensitive and specific approach for GCA assessment and plays a pivotal role in diagnosis of GCA in routine clinical practice.

REGISTRATION

PROSPERO 2020 CRD42020202179.

Efficacy and safety of secukinumab in patients with giant cell arteritis: study protocol for a randomized, parallel group, double-blind, placebo-controlled phase II trial

Background

One key pathological finding in giant cell arteritis (GCA) is the presence of interferon-gamma and interleukin (IL)-17 producing T helper (Th) 1 and Th17 cells in affected arteries. There is anecdotal evidence of successful induction and maintenance of remission with the monoclonal anti-IL-17A antibody secukinumab. Inhibition of IL-17A could therefore represent a potential new therapeutic option for the treatment of GCA.

Methods

This is a randomized, parallel-group, double-blind, placebo-controlled, multi-center, phase II study in which patients, treating physicians, and the associated clinical staff as well as the sponsor clinical team are blinded. It is designed to evaluate efficacy and safety of secukinumab compared to placebo in combination with an open-label prednisolone taper regimen. Patients included are naïve to biological therapy and have newly diagnosed or relapsing GCA. Fifty patients are randomly assigned in a 1:1 ratio to receive either 300 mg secukinumab or placebo subcutaneously at baseline, weeks 1, 2 and 3, and every 4 weeks from week 4. Patients in both treatment arms receive a 26-week prednisolone taper regimen. The study consists of a maximum 6-week screening period, a 52-week treatment period (including the 26-week tapering), and an 8-week safety follow-up, with primary and secondary endpoint assessments at week 28. Patients who do not achieve remission by week 12 experience a flare after remission or cannot adhere to the prednisolone tapering will enter the escape arm and receive prednisolone at a dose determined by the investigator’s clinical judgment. The blinded treatment is continued. Two optional imaging sub-studies are included (ultrasound and contrast-media enhanced magnetic resonance angiography [MRA]) to assess vessel wall inflammation and occlusion before and after treatment. The primary endpoint is the proportion of patients in sustained remission until week 28 in the secukinumab group compared to the proportion of patients in the placebo group. A Bayesian approach is applied.

Discussion

The trial design allows the first placebo-controlled data collection on the efficacy and safety of secukinumab in patients with GCA.

Trial registration

ClinicalTrials.gov NCT03765788. Registration on 5 December 2018, prospective registration, EudraCT number 2018-002610-12; clinical trial protocol number CAIN457ADE11C.

Current advances in giant cell arteritis

PURPOSE OF REVIEW

The aim of this study was to present the latest advances in giant cell arteritis (GCA) care, and recent national and international rheumatology societies guidance which influences clinical practice.

RECENT FINDINGS

Cranial ultrasound reduces diagnostic delay and improves clinical outcomes. Immediate high dose glucocorticoids remain the standard treatment for GCA. Controlled trial evidence using Tocilizumab, an interleukin-6 receptor antagonist, shows good clinical efficacy with steroid-sparing effects.

SUMMARY

Improved patient outcomes require formalizing pathways to diagnosis and closer liaison with rheumatology for long-term management with second-line therapies.

A Tale of Diagnostic Delay with Detrimental Consequences: Illustrating the Challenging Nature of Diagnosing Giant Cell Arteritis

Giant cell arteritis is a medical emergency as severe, irreversible complications may occur if it is not treated in a timely manner. However, in daily practice early diagnosis can be challenging. We report the case of a 70-year-old woman who presented with multiple ischaemic cerebral vascular accidents related to newly diagnosed giant cell arteritis. Review of her charts revealed a substantial delay from the onset of symptoms to diagnosis. This case demonstrates the need for additional efforts to reduce delay in referring patients with giant cell arteritis and the need to implement fast-track clinics to prevent serious complications.

LEARNING POINTS

Giant cell arteritis is a medical emergency and unnecessary diagnostic delay can result in severe complications.Despite implementation of fast-track clinics, diagnostic delay still occurs due to the generic nature of signs and symptoms and inadequate case finding.As diagnostic delay can lead to preventable complications, increased knowledge and awareness of the characteristics and urgency of giant cell arteritis is needed among referring physicians.

Diagnosing Giant Cell Arteritis: A Comprehensive Practical Guide for the Practicing Rheumatologist

Giant cell arteritis (GCA) is the most common large vessel vasculitis in the elderly population. In recent years, advanced imaging has changed the way GCA can be diagnosed in many locations. The GCA fast-track clinic (FTC) approach combined with ultrasound (US) examination allows prompt treatment and diagnosis with high certainty. FTCs have been shown to improve prognosis while being cost effective. However, all diagnostic modalities are highly operator dependent, and in many locations expertise in advanced imaging may not be available. In this paper, we review the current evidence on GCA diagnostics and propose a simple algorithm for diagnosing GCA for use by rheumatologists not working in specialist centres.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis

OBJECTIVE

To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis.

METHODS

Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel.

RESULTS

We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions.

CONCLUSION

These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis

OBJECTIVE

To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis.

METHODS

Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel.

RESULTS

We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions.

CONCLUSION

These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.

Comparison of 18- and 22-MHz probes for the ultrasonographic diagnosis of giant cell arteritis

PURPOSE

Little is known about the diagnostic concordance of images provided by ultrasound probes with emitting frequencies below or above 20 MHz for the diagnosis of giant cell arteritis (GCA).

METHODS

We compared, using Cohen's kappa statistic, data obtained with an 18-MHz and a 22-MHz probe for the ultrasonographic evaluation of temporal arteries in 80 patients referred for suspected GCA.

RESULTS

The halo sign was found in 25% of cases with the 18-MHz probe and in 35% with the 22-MHz probe. The compression sign was positive in 42% of cases with the 18-MHz probe and 48% with the 22-MHz probe. GCA was finally diagnosed in 20 patients (25%). The kappa coefficient of agreement was 0.76 (P < .001) for the halo sign, and 0.75 (P < .001) for the compression sign.

CONCLUSIONS

Images obtained by 18 MHz and 22-MHz frequency probes showed a good level of agreement for the diagnosis of GCA, but the 22-MHz probe yielded a correct diagnosis of GCA in 3 of the 7 patients in whom examination with the 18-MHz probe was negative.

The cut-off values for the intima-media complex thickness assessed by colour Doppler sonography in seven cranial and aortic arch arteries

OBJECTIVES

Colour Doppler sonography (CDS) is becoming ever more important in the diagnosis of GCA. Data on cut-off values for intima-media complex thickness (IMT) that can be used in clinical practice to distinguish between normal and inflamed arteries are limited. We aimed to derive potential cut-off values for IMT of seven preselected arteries by comparing IMT between GCA patients and a control group.

METHODS

We performed CDS of the preselected temporal, facial, occipital, carotid, vertebral, subclavian and axillary arteries in consecutive newly diagnosed GCA patients between October 2013 and September 2019. A 'halo' with positive compression sign was considered a positive finding. We measured the maximum IMT in the preselected arteries and compared it with the maximum IMT of the control group.

RESULTS

We were able to demonstrate a halo sign in at least one of the examined arteries of 244/248 (98.4%) GCA patients. Temporal arteries were the most commonly affected vessels, involved in 192 (77.4%) patients. We found extracranial large vessel involvement in 87 (35.1%) patients. The following cut-off values showed high levels of diagnostic accuracy: ≥0.4 mm for temporal, facial and occipital arteries, ≥0.7 mm for vertebral arteries, and ≥1 mm for carotid, subclavian and axillary arteries.

CONCLUSION

The involvement of a large array of arteries is easily and commonly detected by CDS and provides a high diagnostic yield in patients with suspected GCA. Proposed IMT cut-off values might further improve the diagnostic utility of CDS in these patients.

Ultrasonography in the diagnosis and follow-up of giant cell arteritis

Colour Doppler ultrasonography is the first measure to allow objective bedside assessment of GCA. This article discusses the evidence using the OMERACT filter. Consensus definitions for ultrasonographic changes were agreed upon by a Delphi process, with the 'halo' and 'compression' signs being characteristic. The halo is sensitive to change, disappearing within 2-4 weeks of starting glucocorticoids. Ultrasonography has moderate convergent validity with temporal artery biopsy in a pooled analysis of 12 studies including 965 participants [κ = 0.44 (95% CI 0.38, 0.50)]. The interobserver and intra-observer reliabilities are good (κ = 0.6 and κ = 0.76-0.78, respectively) in live exercises and excellent when assessing acquired images and videos (κ = 0.83-0.87 and κ = 0.88, respectively). Discriminant validity has been tested against stroke and diabetes mellitus (κ=-0.16 for diabetes). Machine familiarity and adequate examination time improves performance. Ultrasonography in follow-up is not yet adequately defined. Some patients have persistent changes in the larger arteries but these do not necessarily imply treatment failure or predict relapses.

Development and Proof of Concept of a Low-Cost Ultrasound Training Model for Diagnosis of Giant Cell Arteritis Using 3D Printing

Objectives: Currently, ultrasound (US) is widely used for the diagnosis of giant cell arteritis (GCA). Our aim was to develop a low-cost US training model for diagnosis of GCA of the temporal and axillary artery using a modern 3D printing system. Methods: We designed an US training model, which enables measurement of the intima-media thickness (IMT) of temporal and axillary arteries using Autodesk Fusion360. This model was printed using a modern 3D printer (Formlabs Form3) and embedded in ballistic gelatine. The ultrasound images including measurement of the IMT by ultrasound specialists in GCA were compared to ultrasound images in acute GCA and healthy subjects. Results: Our ultrasound training model of the axillary and temporal artery displayed a very similar ultrasound morphology compared to real US images and fulfilled the OMERACT ultrasound definitions of normal and pathological temporal and axillary arteries in GCA. The IMT measurements were in line with published cut-off values for normal and pathological IMT values in GCA and healthy individuals. When testing the models on blinded US specialists in GCA, they were identified correctly in all test rounds with an intra-class coefficient of 0.99. Conclusion: The production of low-cost ultrasound training models of normal and pathological temporal and axillary arteries in GCA, which fulfil the OMERACT ultrasound definitions and adhere to the published IMT cut-off values in GCA, is feasible. Ultrasound specialists identified each respective model correctly in every case.

Diagnostic Approaches for Large Vessel Vasculitides

The large vessel vasculitides comprise giant cell arteritis (GCA), Takayasu arteritis (TAK), and chronic periaortitis. The diagnostic approach to these conditions involves the correct use and interpretation of clinical criteria, imaging techniques, and, in case of GCA, temporal artery biopsy. Ultrasound, magnetic resonance imaging (MRI), and computed tomography (CT) reveal a homogeneous, concentric, thickening of the arterial wall. MRI and CT may also reveal aneurysms and stenoses. 18F-Fluorodeoxyglucose (FDG)-PET shows increased FDG uptake of inflamed artery walls delineating increased metabolic activity. Ultrasound, FDG-PET, and MRI are the recommended imaging techniques in GCA and TAK. In patients with a high suspicion of GCA who present with visual disturbances, initiation of high-dose intravenous corticosteroids should not be delayed by imaging. Extracranial large vessel vasculitis may be confirmed by all three modalities, particularly by FDG-PET in case of atypical clinical pictures. In this article, we review the role of the GCA and TAK ACR classification criteria, temporal artery biopsy, conventional angiography, ultrasound, MRI, magnetic resonance angiography (MRA), CT angiography (CTA), and FDG-PET in the diagnostic approach of large vessel vasculitis.

Bilateral Vertebral Artery Vasculitis-A Rare Manifestation of Giant Cell Arteritis and a Difficult Diagnosis Made Possible by 2-[18F]FDG PET/CT

Giant cell arteritis (GCA) is the most common form of large vessel vasculitis. GCA is a medical and ophthalmological emergency, and rapid diagnosis and treatment with high-dose corticosteroids is critical in order to reduce the risk of stroke and sudden irreversible loss of vision. GCA can be difficult to diagnose due to insidious and unspecific symptoms—especially if typical superficial extracranial arteries are not affected. In these cases, verification of clinical diagnosis using temporal artery biopsy is not possible. This example illustrates the diagnostic value of hybrid imaging with 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography (2-[¹⁸F]FDG PET/CT), and the limitations of the temporal artery biopsy in bilateral vertebral GCA, causing transient ischemic attack in the visual cortex. In addition it indicates that inflammation in the artery wall can be visualized on 2-[¹⁸F]FDG PET/CT despite long term and ongoing high dose glucocorticoid treatment.

Presenting features and outcomes of cranial-limited and large-vessel giant cell arteritis: a retrospective cohort study

Objectives: To compare the presenting features and outcomes of patients with cranial-limited (C-) and large-vessel (LV-) giant cell arteritis (GCA).Methods: Data from our GCA cohort were collected retrospectively. Patients who underwent total-body large-vessel imaging within 10 days after commencing steroid therapy were included. Patients with LV involvement were classified as LV-GCA. Presenting features, treatments, and outcomes of LV-GCA and C-GCA patients were compared.Results: 161 patients were included (LV-GCA, n = 100). At baseline, LV-GCA patients were younger than those with C-GCA (73.2 ± 8.9 vs 76 ± 8.8 years, p = 0.018) and had a longer delay to diagnosis (3.5 ± 4.6 vs 2.3 ± 4.9 months, p = 0.001). C-GCA patients had a higher incidence of headache (p = 0.006) and ischaemic optic neuropathy (p < 0.001), whereas LV-GCA patients had more systemic symptoms (fever, p = 0.002; fatigue, p < 0.001; weight loss, p < 0.001; night sweats, p = 0.015) and dry cough (p = 0.031). Corrected cumulative prednisone dose, relapse-free survival, relapse-rate, and incidence of ascending aortic aneurysms were not significantly different between the two subgroups. A steroid-sparing agent was added in 73% of LV- and 55.7% of C-GCA patients (p = 0.027), but was introduced more frequently at baseline in LV-GCA patients (52% vs 23.5%, p = 0.006). LV-GCA patients initially treated with glucocorticoid monotherapy relapsed sooner (relapse-free survival, HR = 0.56, 95% CI 0.41-0.78, p < 0.001) and had a higher relapse rate (relapses per 10 person-years, 6.73 ± 11.50 vs 3.82 ± 10.83, p = 0.011).Conclusion: LV-GCA patients were younger at diagnosis and suffered a longer diagnostic delay. The outcomes of the two subgroups were similar. An earlier introduction of steroid-sparing agents in LV-GCA patients might have played a positive role.

Analysis of Development Mechanism of Giant Cell Arteritis in Nude Mouse Model through Color Duplex Sonography and Computerized Tomography Nanocontrast Agent

To explore the application value of color duplex sonography and enhanced computerized tomography (CT) inspection based on a nanocontrast agent in diagnosis and pathogenesis in giant cell arteritis (GCA), the GCA nude mouse model was constructed. In this study, 40 healthy male BalB/c nude mice aged 6-8 weeks were randomly divided into a control group (no model) and an experimental group (model), with 20 mice in each group, and the temporal artery tissue of GCA patients diagnosed as positive by temporal artery biopsy was implanted into nude mice to construct a GCA nude mouse model. Abdominal aortic biopsy and immunohistochemistry were used to verify the success of the GCA nude mouse model. All nude mice were subjected to color duplex sonography and enhanced CT examination based on a nanocontrast agent. At the same time, the basic indicators such as body weight, temperature, white blood cell (WBC), lymphocytes (LYM), hemoglobin (HGB), and platelet (PLT) were measured, and the protein expression levels of interleukin-6 (IL-6) and signal transducer and activator of transcription 3 (STAT3) were detected by immunohistochemistry. The results showed that the temporal artery wall of the nude mice in the experimental group thickened and the lumen was significantly narrowed, indicating that the cell arteritis model of nude mice was successfully constructed; ultrasound examination showed that the right superficial temporal artery vascular cavity narrowed, the blood flow signal changed like a filling defect around the periphery, and there was a low echo halo. CT examination showed that the left superficial temporal artery narrowed, and the inner diameter of the narrow segment of blood vessels changed like a bead. The body weight of nude mice in the experimental group decreased significantly after the modeling was completed (P < 0.05); after modeling, the body temperature of the nude mice in the experimental group increased significantly (P < 0.05); LYM and HGB values of nude mice in the experimental group were significantly lower than those in the control group (P < 0.05); the content of IL-6, STAT3, IL-6, and STAT3 proteins in the arterial tissue of nude mice in the experimental group was lower than that of the control group (P < 0.05), indicating that color duplex sonography and CT contrast agent technology can be used in the diagnosis and development mechanism research of GC.

Cervical duplex ultrasound for the diagnosis of giant cell arteritis with vertebral artery involvement

Giant cell arteritis (GCA) is a systemic inflammatory arteriopathy of medium and large-sized arteries, predominantly affecting branches of the external carotid artery. Ischemic stroke has been reported in 2.8-7% of patients diagnosed with GCA. The majority of ischemic strokes may involve the posterior circulation as a result of vertebral and/or, less frequently, of basilar artery vasculitis. Prompt diagnosis is crucial since high-dose corticosteroid treatment is highly effective in preventing the occurrence or recurrence of ischemic complications, including posterior circulation ischemic stroke in cases with vertebrobasilar involvement. Cervical duplex sonography (CDS) of the temporal arteries is a powerful diagnostic tool with high sensitivity and specificity for the diagnosis of GCA. In cases with clinical suspicion or a temporal artery ultrasonographic confirmation of GCA, a detailed evaluation of the cervical, axillary, and intracranial arteries with CDS and transcranial-duplex-sonography, respectively, should be part of the ultrasound examination protocol. Specifically, signs of extracranial vertebral artery wall inflammation ("halo" sign) and focal luminar stenoses may be accurately depicted by ultrasounds in high-risk patients or individuals with ischemic stroke attributed to GCA. In this review, we present three cases of GCA and posterior circulation ischemic complications that were initially evaluated with comprehensive neurosonology protocol and were promptly diagnosed with GCA based on the characteristic "halo" sign in the temporal and vertebral arteries. In addition, we discuss the relevant literature concerning the utility of CDS for the early diagnosis of GCA, focusing on the subtype with extracranial arterial involvement, particularly that of the vertebral arteries.

Giant Cell Arteritis: A Systematic Review and Meta-Analysis of Test Accuracy and Benefits and Harms of Common Treatments

This systematic review compares treatment options for patients with giant cell arteritis (GCA) and evaluates the test accuracy of studies used in diagnosing and monitoring GCA. These studies were used to inform evidence-based recommendations for the American College of Rheumatology (ACR)/Vasculitis Foundation (VF) vasculitis management guidelines. A systematic review and search of articles in English in Ovid Medline, PubMed, Embase, and the Cochrane Library was conducted. Articles were screened for suitability, and studies presenting the highest level of evidence were given preference. Three hundred ninety-nine full-text articles addressing GCA questions were reviewed to inform 27 Population, Intervention, Comparison, and Outcome questions. No benefit was found with intravenous glucocorticoids (GCs) compared with high-dose oral GCs in patients with cranial ischemic symptoms (27.4% vs 12.3%; odds ratio [OR] 2.39 [95% confidence interval (CI) 0.75-7.62], [very low certainty of evidence]). Weekly tocilizumab with a 26-week GC taper was superior to a 52-week GC taper in patients achieving remission (risk ratio 4.00 [95% CI 1.97-8.12], [low certainty of evidence]). Non-GC immunosuppressive therapies with GCs compared with GCs alone showed no statistically significant in relapse at 1 year (OR 0.87 [95% CI 0.73-1.04], [moderate certainty of evidence]) or serious adverse events (OR 0.81 [95% CI 0.54-1.20]; [moderate certainty of evidence]). Temporal artery biopsy has a sensitivity of 61% (95% CI 38%-79%) and a specificity of 98% (95% CI 95%-99%) in patients with a clinical diagnosis of suspected GCA. This comprehensive systematic review synthesizes and evaluates the benefits and harms of different treatment options and the accuracy of commonly used tests for the diagnosis and monitoring of GCA.

A Review on the Value of Imaging in Differentiating between Large Vessel Vasculitis and Atherosclerosis

Imaging is becoming increasingly important for the diagnosis of large vessel vasculitis (LVV). Atherosclerosis may be difficult to distinguish from LVV on imaging as both are inflammatory conditions of the arterial wall. Differentiating atherosclerosis from LVV is important to enable optimal diagnosis, risk assessment, and tailored treatment at a patient level. This paper reviews the current evidence of ultrasound (US), 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography (FDG-PET), computed tomography (CT), and magnetic resonance imaging (MRI) to distinguish LVV from atherosclerosis. In this review, we identified a total of eight studies comparing LVV patients to atherosclerosis patients using imaging—four US studies, two FDG-PET studies, and two CT studies. The included studies mostly applied different methodologies and outcome parameters to investigate vessel wall inflammation. This review reports the currently available evidence and provides recommendations on further methodological standardization methods and future directions for research.

[Management of patients with a suspicion of giant cell arteritis: Survey among general practitioners and specialists]

INTRODUCTION

Headache, visual disturbances and shoulder and hip girdle pain are frequent symptoms of consultation and the diagnosis of giant cell arteritis (GCA) can be evoked in these situations. However, GCA is a rare disease, and the management modalities of a clinical suspicion of GCA are poorly described, which warranted this study.

METHODS

This is a survey evaluating the management of a suspected case of GCA. The questionnaires were sent to general practitioners (GPs), members of the French Rheumatology Society (SFR) and the French National Society of Internal Medicine (SNFMI) RESULTS: One thousand four hundred and fifty two physicians responded to the survey, including 967 GPs (66.6 %) and 485 other specialists (33.4 %). GPs immediately referred the patient to the emergency room in 42 % of cases, and to a specialist colleague in 72 % of cases in the presence of visual symptoms. GPs and other specialists reported performing temporal artery biopsy (TAB) respectively in 46.7 % and 69.7 % of cases (P<0.05). GPs and other specialists reported using diagnostic imaging in 7.4 % and 16.2 % of cases, respectively (P<0.05). Temporal artery ultrasound was the most used diagnostic imaging. The average prednisone equivalent dose prescribed as initial treatment was 1mg/kg/day for GPs and 0.7mg/kg/day for other specialists (P<0.05).

CONCLUSION

Some suspected GCA patients would be managed by their GPs. Imaging was little used for the diagnosis of GCA and TAB remained the preferred diagnostic examination. The initial prednisone equivalent dose varied between GP and other specialists.

Prognostic impacts of glucocorticoid treatment in patients with polymyalgia rheumatica and giant cell arteritis

Identifying comorbidities in polymyalgia rheumatica/giant cell arteritis (PMR/GCA) is crucial for patients' outcomes. The present study aimed to evaluate the impact of the inflammatory process and glucocorticoid treatment on aortic arterial stiffness and body composition in PMR/GCA. 77 patients with newly diagnosed PMR/GCA were treated with oral glucocorticoids and followed for 40 weeks. Aortic pulse wave velocity (PWV) was measured at baseline and during the follow-up period and compared to the results of temporal artery biopsy (TAB) and 18F-FDG PET/CT. Body composition was assessed by total body DXA at baseline and the end of the study. Of 77 patients (49 (63.6%) female, mean of age: (71.8 ± 8.0)), 64 (83.1%) had pure PMR, 10 (13.0%) concomitant PMR and GCA, and 3 (3.9%) pure GCA. Compared to baseline values, aortic PWV was initially decreased at week 16 (p = 0.010) and remained lower than baseline at week 28 (p = 0.002) and week 40 (p < 0.001), with no association with results of TAB and 18F-FDG PET/CT. Aortic PWV was significantly associated with age, male gender, left systolic and diastolic blood pressure, right diastolic blood pressure, and CRP. Total bone mineral content (BMC) was decreased in both genders (p < 0.001), while fat mass (FM) was significantly increased (p < 0.001). However, lean body mass did not significantly change during the study. Changes in FM were correlated with cumulative prednisolone dose (rho: 0.26, p = 0.031). Glucocorticoid treatment of patients with PMR/GCA had several prognostic impacts. Arterial stiffness was decreased due either to the treatment or a reduction in the inflammatory load. Additionally, treatment led to changes in body composition, including a decrease in BMC and FM excess.

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.

Update on the Treatment of Giant Cell Arteritis and Polymyalgia Rheumatica

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are considered 2 diseases on the same spectrum due to their many underlying similarities. In recent years, both diseases have witnessed both diagnostic and treatment advances, which shaped the way we manage them. In this article, the authors focus on different diagnostic modalities in GCA as well as the presence of different clinical phenotypes and the role of screening for aortic involvement. The authors also discuss traditional treatments and the role of evolving steroid-sparing agents in the management of both GCA and PMR.

Photoacoustic imaging for non-invasive examination of the healthy temporal artery - systematic evaluation of visual function in healthy subjects

PURPOSE

Photoacoustic (PA) imaging has the potential to become a non-invasive diagnostic tool for giant cell arteritis, as shown in pilot experiments on seven patients undergoing surgery. Here, we present a detailed evaluation of the safety regarding visual function and patient tolerability in healthy subjects, and define the spectral signature in the healthy temporal artery.

METHODS

Photoacoustic scanning of the temporal artery was performed in 12 healthy subjects using 59 wavelengths (from 680 nm to 970 nm). Visual function was tested before and after the examination. The subjects' experience of the examination was rated on a 0-100 VAS scale. Two- and three-dimensional PA images were generated from the spectra obtained from the artery.

RESULTS

Photoacoustic imaging did not affect the best corrected visual acuity, colour vision (tested with Sahlgren's Saturation Test or the Ishihara colour vision test) or the visual field. The level of discomfort was low, and only little heat and light sensation were reported. The spectral signature of the artery wall could be clearly differentiated from those of the subcutaneous tissue and skin. Spectral unmixing provided visualization of the chromophore distribution and overall architecture of the artery.

CONCLUSIONS

Photoacoustic imaging of the temporal artery is well tolerated and can be performed without any risk to visual function, including the function of the retina and the optic nerve. The spectral signature of the temporal artery is specific, which is promising for future method development.

Is the intima-media thickness of temporal and axillary arteries influenced by cardiovascular risk?

Objectives

To measure with US the intima-media thickness (IMT) of temporal (superficial, parietal and frontal branches) and axillary arteries in subjects without a diagnosis of GCA and/or PMR with different cardiovascular (CV) risk; and to assess the performance of previously proposed cut-off values for normal IMT.

Methods

Subjects ≥ 50 years without a diagnosis of GCA or PMR were included. Bilateral US of the temporal arteries, including the frontal and parietal branches, and axillary arteries was performed by two sonographers using a 10–22 MHz and 6–18 MHz probe. The following previously proposed cut-offs were considered: superficial temporal artery: 0.42 mm; frontal branch: 0.34 mm; parietal branch: 0.29 mm; axillary artery: 1.0 mm.

Results

A total of 808 arteries in 101 subjects were evaluated; of these, 31 (30.7%) were classified as very high CV risk, seven (6.9%) as high, 34 (33.7%) as moderate and 29 (28.7%) as low risk. Subjects with very high or high risk showed higher IMT than those with moderate or low risk in the superficial temporal arteries [0.23 (s.d. 0.07) vs 0.20 (s.d. 0.04), P &lt; 0.01] and in the axillary arteries [0.54 (s.d. 0.17) vs 0.48 (s.d. 0.10), P = 0.002]. The IMT was higher than the reference cut-off in 13/808 (1.6%) arteries, in ≥1 artery in 10/101 subjects (10.1%). Of these 10 subjects, 8 (80%) were classified as having very high or high risk.

Conclusion

Our results suggest that CV risk might influence the US-determined IMT of the temporal and axillary arteries in subjects without GCA. Therefore, in patients with suspected GCA, particular attention should be paid when measuring the IMT in those patients with very high/high CV risk.

A Case of Microscopic Polyangiitis Presenting as Cranial Giant Cell Arteritis

We present a case of a 63-year old man with microscopic polyangiitis (MPA) in which the initial clinical presentation resembled the cranial form of giant cell arteritis (GCA) (headache, jaw claudication, low grade fever and raised inflammation markers). Ultrasound of both superficial common temporal arteries revealed signs indicative of vessel wall inflammation. Based on clinical picture and compatible imaging findings, treatment with corticosteroids for GCA was started. After initial improvement and steroid tapering, lung infiltrations, mononeuritis of the right peroneal nerve and cutaneous necrosis appeared and p-Antineutrophil cytoplasmic antibodies (ANCA) turned out to be positive. Three intravenous cyclophosphamide pulses for MPA led in disease remission and maintenance treatment with azathioprine followed. Two years later, the patient has no symptoms and laboratory parameters are normal. This case highlights that MPA can affect temporal arteries and can masquerade as cranial GCA.

Temporal Artery Ultrasound to Diagnose Giant Cell Arteritis: A Practical Guide

The diagnostic modalities for giant cell arteritis (GCA) have evolved significantly in recent years. Among the different diagnostic tools developed, Doppler ultrasound of the temporal arteries, with a sensitivity and specificity reaching 69% and 82%, respectively, is now recognized as superior and, therefore, is a first-line diagnostic tool in GCA. Moreover, with the increasing development of new ultrasound technologies, the accuracy of Doppler ultrasound in GCA seems to be constantly improving. In this article, we describe in detail the scanning technique to perform while realizing Doppler ultrasound of temporal arteries to assess GCA, as well as the diagnostic performance of this tool according to current literature.

Diagnostic value of axillary artery ultrasound in patients with suspected giant cell arteritis

Objectives

To compare colour duplex ultrasonography (CDU) findings with axillary ¹⁸F-fluorodeoxyglucose (FDG) PET/CT findings and to compare the diagnostic performance of temporal and axillary artery CDU with temporal artery CDU alone.

Methods

Patients suspected of GCA were retrospectively included. Presence of a halo or occlusion was considered a positive CDU finding. FDG-PET/CT-assessed axillary artery involvement was defined as axillary artery FDG uptake higher than liver uptake. The reference was the clinical diagnosis after 6 months, which was based on symptomatology and additional diagnostic tests, with the exception of CDU.

Results

Of the 113 included patients, GCA was diagnosed in 41. Twenty-eight out of 41 GCA patients underwent a FDG-PET/CT. FDG-PET-assessed extra-cranial GCA was present in 20/41 patients, of which 13 showed axillary involvement on FDG-PET/CT. An axillary halo was found in eight of these 13 patients. Six out of the 20 patients with FDG-PET-assessed GCA showed no axillary involvement on CDU or FDG-PET/CT. Five of them had single artery involvement on FDG-PET/CT (two aorta; three vertebral artery). One patient had an axillary occlusion on CDU, consistent with FDG-PET/CT results. Overall, sensitivity and specificity of temporal artery CDU was 52% (95% CI: 35, 67) and 93% (95% CI: 84, 97), respectively. Adding axillary artery results improved sensitivity to 71% (95% CI: 55, 84), while specificity did not change.

Conclusion

Presence of an axillary halo or occlusion on CDU is consistent with axillary artery FDG-PET/CT results, but a negative CDU does not rule out axillary involvement. Adding axillary artery assessment to temporal artery assessment may substantially increase the diagnostic performance of CDU.

Giant cell arteritis: A nationwide, population-based cohort study on incidence, diagnostic imaging, and glucocorticoid treatment

AIM

The study investigated the development over time of the incidence, diagnostic imaging, and treatment of giant cell arteritis (GCA).

METHOD

This nationwide, population-based cohort study was conducted in Denmark using medical and administrative registries. Incident GCA cases from 1996-2018 were defined as patients aged ≥50 years registered with a first-time GCA diagnosis and ≥3 prescriptions for glucocorticoids (GCs) within 6 months after diagnosis. We determined incidence rates of GCA, the proportion of patients still receiving GCs >2 years after diagnosis, the proportion of patients receiving temporal artery biopsies (TAB) and diagnostic imaging including ultrasound, positron emission tomography, magnetic resonance, and/or computed tomography angiography at the time of diagnosis.

RESULTS

We identified 9908 incident GCA cases. The incidence rates of GCA remained stable at 19-25 per 100,000 people aged >50 years from 1996-2018. The proportion of GCA patients receiving a TAB remained constant until 2016, after which it promptly declined from 70-80% to 29-39%. In contrast, the proportion of patients receiving diagnostic imaging increased from 2% to 66% from 2000-2018. The proportion of GCA patients remaining in GC treatment has steadily decreased from 1996-2016, but remains high at 64%, 40%, and 34% after 2, 5, and 10 years following the diagnosis, respectively. The cumulative GC dose has remained relatively stable.

CONCLUSION

Incidence rates of GCA have remained stable since 1996 despite increasing use of diagnostic imaging. There is a clear discrepancy between current international GCA treatment guidelines and the clinical practice up to 2018.

Clinical, Laboratory and Ultrasonographic Interrelations in Giant Cell Arteritis

OBJECTIVES

The diagnosis of giant cell arteritis (GCA) is based on the presence of clinical and laboratory features. Color-duplex sonography (CDS) may supplant the limited sensitivity of temporal artery biopsy. The aim of our work was to characterize clinical and laboratory findings in patients with positive CDS for GCA.

MATERIALS AND METHODS

Retrospective study of all consecutive patients of our center fulfilling American College of Rheumatology criteria for GCA who performed CDS study between 2009-2019. Data on clinical and laboratory features were compared in two groups: with and without halo sign.

RESULTS

Ninety-one patients were included. Temporal halo sign was identified in 46% of patients. Halo sign was more often present in older patients (77 ± 8 vs 73 ± 8 years, p = 0.022), associated with systemic features (58% vs 42%, p = 0.011), higher erythrocyte sedimentation rate (84 ± 26 vs 74 ± 34 mm/hour, p = 0.020), and lower hemoglobin values (10.9 ± 1.5 vs 12.1 ± 1.6 g/dL, p < 0.001). The number of patients under corticosteroids before CDS was higher in the group without halo (62% vs 33%, p = 0.005). Ischemic stroke occurred in 17 patients (19%), 76% in the vertebrobasilar territory, and stroke was associated with vertebral halo sign (p < 0.001).

CONCLUSIONS

Halo sign was present in half of our patients. Previous corticosteroids treatment decreased positive CDS findings. Systemic symptoms and laboratory findings are more notorious in halo sign subgroup of patients. Stroke cases in GCA patients disproportionally affected the posterior circulation. Ultrasonography provides information about a more pronounced systemic involvement and a higher risk of major complications.

Incidence and prevalence of giant cell arteritis in Ontario, Canada

OBJECTIVE

To estimate trends in the incidence and prevalence of GCA over time in Canada.

METHODS

We performed a population-based study of Ontario health administrative data using validated case definitions for GCA. Among Ontario residents ≥50 years of age we estimated the annual incidence and prevalence rates between 2000 and 2018. We performed sensitivity analyses using alternative validated case definitions to provide comparative estimates.

RESULTS

Between 2000 and 2018 there was a relatively stable incidence over time with 25 new cases per 100 000 people >50 years of age. Age-standardized incidence rates were significantly higher among females than males [31 cases (95% CI: 29, 34) vs 15 cases (95% CI: 13, 18) per 100 000 in 2000]. Trends in age-standardized incidence rates were stable among females but increased among males over time. Incidence rates were highest among those ≥70 years of age. Standardized prevalence rates increased from 125 (95% CI 121, 129) to 235 (95% CI 231, 239) cases per 100 000 from 2000 to 2018. The age-standardized rates among males rose from 76 (95% CI 72, 81) cases in 2000 to 156 (95% CI 151, 161) cases per 100 000 population in 2018. Between 2000 and 2018, the age-standardized rates among females similarly increased over time, from 167 (95% CI 161, 173) to 304 (95% CI 297, 310) cases per 100 000 population.

CONCLUSION

The incidence and prevalence of GCA in Ontario is similar to that reported in the USA and northern Europe and considerably higher than that reported for southern Europe and non-European populations.

The impact of disease extent and severity detected by quantitative ultrasound analysis in the diagnosis and outcome of giant cell arteritis

OBJECTIVES

To develop a quantitative score based on colour duplex sonography (CDS) to predict the diagnosis and outcome of GCA.

METHODS

We selected patients with positive CDS and confirmed diagnosis of GCA recruited into the TA Biopsy (TAB) vs Ultrasound in Diagnosis of GCA (TABUL) study and in a validation, independent cohort. We fitted four CDS models including combinations of the following: number and distribution of halos at the TA branches, average and maximum intima-media thickness of TA and axillary arteries. We fitted four clinical/laboratory models. The combined CDS and clinical models were used to develop a score to predict risk of positive TAB and clinical outcome at 6 months.

RESULTS

We included 135 GCA patients from TABUL (female: 68%, age 73 (8) years) and 72 patients from the independent cohort (female: 46%, age 75 (7) years). The best-fitting CDS model for TAB used maximum intima-media thickness size and bilaterality of TA and axillary arteries' halos. The best-fitting clinical model included raised inflammatory markers, PMR, headache and ischaemic symptoms. By combining CDS and clinical models we derived a score to compute the probability of a positive TAB. Model discrimination was fair (area under the receiver operating characteristic curve 0.77, 95% CI: 0.68, 0.84). No significant association was found for prediction of clinical outcome at 6 months.

CONCLUSION

A quantitative analysis of CDS and clinical characteristics is useful to identify patients with a positive biopsy, supporting the use of CDS as a surrogate tool to replace TAB. No predictive role was found for worse prognosis.