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

The usefulness of 18F-FDG-PET/CT in detecting musculoskeletal and vascular involvement in patients with polymyalgia rheumatica receiving glucocorticoids

OBJECTIVE

Fluorine-18-fluorodeoxyglucose (18F-FDG) PET/CT is a promising diagnostic tool for polymyalgia rheumatica (PMR) and large vessel vasculitis (LVV). PET/CT performance is recommended before the onset of steroid therapy because glucocorticoids (GC) may decrease the intensity of FDG uptake. However, this is not always possible in clinical practice. Our aim was to assess if PET/CT could be also useful to detect musculoskeletal and vascular involvement in patients receiving GC.

METHODS

Single-center study of patients with PMR diagnosis based on 2012 EULAR/ACR criteria who underwent a PET/CT scan due to LVV suspicion. We compared the musculoskeletal and vascular FDG uptake between two groups: (a) steroid-naïve and (b) steroid-resistant patients. A sub-analysis was conducted in patients who were receiving GC to discern if the cumulative prednisone dose influences the FDG uptake.

RESULTS

We evaluated 75 patients (27 men/ 48 women); mean age±SD: 68.2 ± 10.7 years. PET/CT was performed in 14 steroid-naïve and 61 steroid-resistant patients. Patients under GC had received a median cumulative prednisone dose of 1.8 [0.6-3.9] g. The pattern of musculoskeletal FDG uptake was similar in steroid-naïve and steroid-resistant patients. FDG uptake in the vessel wall was more frequently detected in steroid-naïve patients. However, PET/ CT was also useful to detect LVV in 62.3 % of the patients who were receiving GC. The percentage of patients who had positive PET/CT scans tended to decrease with higher cumulative prednisone doses.

CONCLUSION

Even though GC therapy may decrease the 18-FDG uptake, PET/CT continues to be a useful tool to detect musculoskeletal and LVV involvement in PMR.

Large vessel giant cell arteritis

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

Development of the Takayasu Arteritis Integrated Disease Activity Index

OBJECTIVE

Accurate clinical assessment of disease activity in Takayasu arteritis (TAK) can be challenging. 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) can directly measure vascular inflammation. This study details the development of a new type of disease activity index called the Takayasu's Arteritis Integrated Disease Activity Index (TAIDAI).

METHODS

Clinical symptoms for TAIDAI were identified from a literature review. Each symptom was paired with FDG-PET findings in corresponding arterial territories. Constitutional symptoms were paired with acute phase reactant levels. One point was given for each clinical symptom paired with supporting FDG-PET or laboratory abnormalities and summed into the TAIDAI score. A TAIDAI of ≥1 defined active disease. To assess performance of TAIDAI, face validity, content validity, and sensitivity to change were evaluated within a prospective observational cohort study of patients with TAK.

RESULTS

Seventeen clinical symptoms were paired with imaging or laboratory abnormalities. In a cohort of 96 patients contributing 204 study visits, TAIDAI showed excellent sensitivity (96.3%) and good specificity (79.2%) compared to physician's clinical assessment. TAIDAI significantly correlated with physician global assessment, PET Vascular Activity Score, patient global assessment, and acute phase reactant levels. In patients treated with either tumor necrosis factor inhibitors or tocilizumab, a TAIDAI of 0 was achieved in 21 (91%) of 23 patients who met a predefined definition of clinical response.

CONCLUSION

TAIDAI is new type of disease activity index in TAK in which clinical symptoms are integrated with specific laboratory and imaging findings. TAIDAI should be validated in future randomized controlled trials in TAK.

Association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms in giant cell arteritis

Background

A positive PET scan at diagnosis was associated with a greater yearly increase in ascending and descending aortic diameter and thoracic aortic volume in patients with giant cell arteritis (GCA). Radiologic and histopathologic vascular abnormalities persist in a subset of treated patients despite clinical remission. The aim of this study was to evaluate the association between vascular FDG uptake during follow-up and the development of thoracic aortic aneurysms.

Methods

We recently performed a prospective cohort study of 106 GCA patients, who underwent FDG PET and CT imaging at diagnosis and CT imaging yearly for a maximum of 10 years. In this post hoc analysis, GCA patients who also have had FDG PET imaging during follow-up were included. PET scans were visually scored (0-3) at 7 vascular areas. PET scans were considered positive in case of FDG uptake ≥grade 2 in any large vessel.

Results

Eighty-eight repeat PET scans were performed in 52 out of 106 GCA patients, who were included in the original prospective cohort. Fifty-five (63%) PET scans were done at the time of a relapse and 33 (38%) were done while in remission. Nine out of ten patients with an incident thoracic aortic aneurysm had both a positive PET scan at diagnosis and during follow-up.

Conclusion

In addition to the intensity and extent of the initial vascular inflammation, ongoing aortic inflammation may contribute to the development of thoracic aortic aneurysms in GCA. However, this hypothesis should be confirmed in a large prospective trial with repeat PET scans at predefined time points during follow-up.

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

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

Persistent aortic inflammation in patients with giant cell arteritis

OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Role of Imaging in Diagnosis and Monitoring of Large Vessel Vasculitis

Technological advances and increased recognition of the prevalence and implications of large vessel vasculitis have led to robust research into various imaging techniques. Although there is still debate about which modality to choose in specific clinical scenarios, Ultrasound, PET/CT, MRI/A, and CT/A offer complementary information regarding diagnosis, disease activity, and vascular complication monitoring. Recognition of the strengths and limitations of each technique is important for appropriate application in clinical practice.

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.

Imaging of giant cell arteritis - recent advances

Imaging is increasingly being used to guide clinical decision-making in patients with giant cell arteritis (GCA). While ultrasound has been rapidly adopted in fast-track clinics worldwide as an alternative to temporal artery biopsy for the diagnosis of cranial disease, whole-body PET/CT is emerging as a potential gold standard test for establishing large vessel involvement. However, many unanswered questions remain about the optimal approach to imaging in GCA. For example, it is uncertain how best to monitor disease activity, given there is frequent discordance between imaging findings and conventional disease activity measures, and imaging changes typically fail to resolve completely with treatment. This chapter addresses the current body of evidence for the use of imaging modalities in GCA across the spectrum of diagnosis, monitoring disease activity, and long-term surveillance for structural changes of aortic dilatation and aneurysm formation and provides suggestions for future research directions.

Association of 18 F-Fluorodeoxyglucose-Positron Emission Tomography Activity With Angiographic Progression of Disease in Large Vessel Vasculitis

OBJECTIVE

To assess whether vascular activity seen on 18 F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scan is associated with angiographic change in large vessel vasculitis (LVV).

METHODS

Patients with LVV were recruited into a prospective cohort. All patients underwent magnetic resonance angiography or computed tomography angiography and FDG-PET imaging. Follow-up imaging using the same imaging modalities was obtained ≥6 months later per a standardized imaging protocol. Arterial damage, defined as stenosis, occlusion, or aneurysm, and corresponding FDG uptake were evaluated in 17 arterial territories. On follow-up, development of new lesions was recorded, and existing lesions were characterized as improved, worsened, or unchanged.

RESULTS

A total of 1,091 arterial territories from 70 patients with LVV (38 patients with Takayasu arteritis, 32 patients with giant cell arteritis) were evaluated. Over a median 1.6 years of follow-up, new lesions developed only in 8 arterial territories in 5 patients with Takayasu arteritis. Arterial lesions improved in 16 territories and worsened in 6 territories. Most arterial territories that did not have vascular activity on FDG-PET scan at baseline had no angiographic change over the follow-up period (787 [99%] of 793). Few territories with baseline FDG-PET activity had angiographic change over time (24 [8%] of 298), but of the territories that developed angiographic change, 80% had FDG-PET activity at baseline. Within the same patient, an arterial territory with baseline FDG-PET activity had significantly increased risk for angiographic change compared to a paired arterial territory without FDG-PET activity (odds ratio 19.49 [95% confidence interval 2.44-156.02]; P < 0.01). Concomitant edema and wall thickening further increased risk for angiographic change.

CONCLUSION

Development of angiographic change was infrequent in this cohort of patients with LVV. A lack of baseline FDG-PET activity was strongly associated with stable angiographic disease. In cases of angiographic progression, change was preceded by the presence of FDG-PET activity.

Mesenteric Artery Dissection and Wall-Thickening, Case Study and General Review

Mesenteric artery dissection (D) and wall-thickening (WT) are rare vasculopathies that can lead to serious complications. This is a single center analysis of all patients evaluated for mesenteric arterial (celiac, superior (SMA) and/or inferior mesenteric (IMA)) D and/or WT from January 1, 2000, to January 31, 2020 at our hospital. Among the 101 included patients, the average age was 55.6 ± 13.6 years, mostly affecting men (62%). There were 20 celiac artery D, 8 WT, 15 D with WT, 15 SMA D, 7 WT, 8 D with WT, one IMA D, two WT, and 25 with multiple arterial involvement. Primary etiologies included segmental arterial mediolysis (SAM) (n = 17), isolated D (n = 17), localized vasculitis of the gastrointestinal tract (LVGT) (n = 16), fibromuscular dysplasia (FMD) (n = 13), extension of thoracoabdominal aortic D (n = 12), and trauma (n = 12). Most (71%) patients presented with abdominal pain. Hypertension (55%), hyperlipidemia (33%) and tobacco use (31%) were prevalent. Management included conservative (22%), medical (47%), endovascular (19%), and/or open repair (12%) with high in-hospital survival (98%) and symptom relief (73%). Our paper complements the scarce literature addressing the diagnosis and management of rare mesenteric vasculopathies. Most patients improved with conservative management, reserving endovascular or surgical interventions for symptomatic patients with more complicated presentations.

Vessel inflammation and morphological changes in patients with large vessel vasculitis: a retrospective study

OBJECTIVE

The aim was to identify any association between imaging signs of vessel wall inflammation (positron emission tomography-CT (PET-CT) score and CT/MR wall thickening) and synchronous and subsequent vascular damage (stenoses/dilations) in patients with large vessel vasculitis (LVV).

METHODS

Consecutive patients with LVV referred to a tertiary centre in 2007-2020 with baseline PET-CT and morphological imaging (CT/MR angiography) performed within 3 months were included. All available PET-CT and CT/MR scans were reviewed to assess PET-CT uptake (4-point semi-quantitative score), wall thickening, stenoses and dilations for 15 vascular segments. The associations of baseline PET score and CT/MR wall thickening with synchronous and incident stenoses/dilations at CT/MR performed 6-30 months from baseline were evaluated in per-segment and per-patient analyses. Respective areas under the receiver operating characteristic curve (AUC) were calculated.

RESULTS

We included 100 patients with LVV (median age: 48 years, 22% males). Baseline PET score and wall thickening were strongly associated (Cuzick non-parametric test for trend across order groups (NPtrend) <0.001). The association with synchronous stenoses/dilations was weak for PET score (NPtrend=0.01) and strong for wall thickening (p<0.001). In per-patient analyses, sensitivity/specificity for ≥1 synchronous stenoses/dilations were 44%/67% for PET score ≥2 and 66.7%/60.5% for wall thickening. Subsequent CTs/MRs were available in 28 patients, with seven incident stenoses/dilations. Baseline PET score was strongly associated with incident stenoses/dilations (p=0.001), while baseline wall thickening was not (p=0.708), with AUCs for incident stenoses/dilations of 0.80 for PET score and 0.52 for wall thickening.

CONCLUSION

PET score and wall thickening are strongly associated, but only baseline PET score is a good predictor of incident vessel wall damage in LVV.

Large-vessel vasculitis

Large-vessel vasculitis (LVV) manifests as inflammation of the aorta and its major branches and is the most common primary vasculitis in adults. LVV comprises two distinct conditions, giant cell arteritis and Takayasu arteritis, although the phenotypic spectrum of primary LVV is complex. Non-specific symptoms often predominate and so patients with LVV present to a range of health-care providers and settings. Rapid diagnosis, specialist referral and early treatment are key to good patient outcomes. Unfortunately, disease relapse remains common and chronic vascular complications are a source of considerable morbidity. Although accurate monitoring of disease activity is challenging, progress in vascular imaging techniques and the measurement of laboratory biomarkers may facilitate better matching of treatment intensity with disease activity. Further, advances in our understanding of disease pathophysiology have paved the way for novel biologic treatments that target important mediators of disease in both giant cell arteritis and Takayasu arteritis. This work has highlighted the substantial heterogeneity present within LVV and the importance of an individualized therapeutic approach. Future work will focus on understanding the mechanisms of persisting vascular inflammation, which will inform the development of increasingly sophisticated imaging technologies. Together, these will enable better disease prognostication, limit treatment-associated adverse effects, and facilitate targeted development and use of novel therapies.

Advances in Radiopharmaceutical Sciences for Vascular Inflammation Imaging: Focus on Clinical Applications

Biomedical imaging technologies offer identification of several anatomic and molecular features of disease pathogenesis. Molecular imaging techniques to assess cellular processes in vivo have been useful in advancing our understanding of several vascular inflammatory diseases. For the non-invasive molecular imaging of vascular inflammation, nuclear medicine constitutes one of the best imaging modalities, thanks to its high sensitivity for the detection of probes in tissues. 2-[¹⁸F]fluoro-2-deoxy-d-glucose ([¹⁸F]FDG) is currently the most widely used radiopharmaceutical for molecular imaging of vascular inflammatory diseases such as atherosclerosis and large-vessel vasculitis. The combination of [¹⁸F]FDG and positron emission tomography (PET) imaging has become a powerful tool to identify and monitor non-invasively inflammatory activities over time but suffers from several limitations including a lack of specificity and avid background in different localizations. The use of novel radiotracers may help to better understand the underlying pathophysiological processes and overcome some limitations of [¹⁸F]FDG PET for the imaging of vascular inflammation. This review examines how [¹⁸F]FDG PET has given us deeper insight into the role of inflammation in different vascular pathologies progression and discusses perspectives for alternative radiopharmaceuticals that could provide a more specific and simple identification of pathologies where vascular inflammation is implicated. Use of these novel PET tracers could lead to a better understanding of underlying disease mechanisms and help inform the identification and stratification of patients for newly emerging immune-modulatory therapies. Future research is needed to realize the true clinical translational value of PET imaging in vascular inflammatory diseases.

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.

Cul de Sac : An Unusual Presentation of Giant Cell Arteritis

Giant cell arteritis (GCA), previously referred to as temporal arteritis, continues to pose significant diagnostic challenges to clinicians as it could have unusual and atypical presentations. We present the case of a 69-year-old Caucasian male who had presented with painful scrotal swelling and bilateral arm pain and was eventually diagnosed with GCA based on histological findings. His symptoms resolved completely with the initiation of high-dose steroids. It is important to note that some clinical manifestations of GCA could be subtle, atypical, and maybe entirely extracranial. A high index of suspicion is helpful when diagnosing patients who present with non-specific or constitutional symptoms as delay in diagnosis or treatment in these patients could result in severe adverse outcomes.

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.

Multimodality Imaging of Large Vessel Vasculitis, From the AJR Special Series on Inflammation

Large vessel vasculitis (LVV) is a non-infectious inflammation of the large vessels, including the aorta and its main branches. Imaging plays an essential role in diagnosing LVV, given the challenges of tissue biopsy. This article reviews the types of LVV, and the multimodality imaging tools available to establish the diagnosis in patients with LVV. The cornerstone of imaging diagnosis is morphologic assessment using grey-scale ultrasound, combined grey-scale US with color Doppler US, CTA, or MRA. In the last decade, substantial progress has been made in functional and molecular imaging with FDG PET/CT for the diagnosis of LVV. Investigation is ongoing to develop novel MRA techniques and new PET tracers to assess disease activity and to differentiate the various vasculitides. An algorithm is provided to guide imaging technique selection based on the patient's specific clinical presentation.

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.

Systemic vasculitides and the role of multitechnique imaging in the diagnosis

Vasculitis, a systemic disease characterised by inflammation of the blood vessels, remains challenging to diagnose and manage. Vessel size has been the basis for classifying systemic vasculitides. Imaging plays a vital role in diagnosing this challenging disease. This review article aims (a) to summarise up-to-date literature in this field, as well as include classification updates and (b) to review available imaging techniques, recent advances, and emphasis on imaging findings to diagnose large vessel vasculitides.

Ultrasound for diagnosis and follow-up of chronic axillary vasculitis in patients with long-standing giant cell arteritis

Aims:

To assess intima-media thickness (IMT) changes measured by ultrasound in axillary arteries of giant cell arteritis (GCA) patients over time and to calculate an ultrasound cut-off value for the diagnosis of chronic axillary artery involvement in patients with longstanding GCA.

Methods:

Ultrasound of both axillary arteries was performed in 109 GCA patients at time of diagnosis and at several follow-up visits and in 40 healthy controls (HCs). IMT determined at the prospective follow-up visit was compared between GCA patients with (axGCA) and without (non-axGCA) vasculitis of axillary arteries at baseline, as well as with HCs. Changes in IMT were depicted. Receiver operating characteristics were performed for cut-off calculations. Inter-/intra-rater agreement was evaluated using stored images and intraclass correlation coefficient (ICC).

Results:

Seventy-three patients were in the axGCA and 36 in the non-axGCA group. Pathological IMT of axillary arteries (axGCA) declined in the first 18 months of treatment by −0.5 mm, (range −2.77 to 0.50), independent of age and gender. Median IMT, after median disease duration of 48 months (16–137), was 0.90 mm (0.46–2.20) in axGCA and 0.60 mm (0.42–1.0) in the non-axGCA group pooled with HCs. An IMT of 0.87 mm was highly specific (specificity 96%, sensitivity 61%) for diagnosis of chronic axGCA. Intra-rater and inter-reader agreement of ultrasound images were good [ICC 0.96–1.0 (three readers) and 0.87, respectively].

Conclusion:

Pathological IMT of the axillary artery declined under treatment. An IMT of 0.87 mm is highly specific for diagnosis of chronic vasculitis of axillary arteries in long-standing GCA patients.

Imaging for Diagnosis, Monitoring, and Outcome Prediction of Large Vessel Vasculitides

Purpose of Review

To discuss and summarize the latest evidence on imaging techniques in giant cell arteritis (GCA) and Takayasu arteritis (TAK). This is a report on the performance of ultrasound (US), magnetic resonance imaging (MRI), computed tomography (CT), 18F-fluorodeoxyglucose positron emission tomography (18-FDG-PET), and other emerging imaging techniques in diagnosis, outcome prediction, and monitoring of disease activity.

Recent Findings

Imaging techniques have gained an important role for diagnosis of large vessel vasculitides (LVV). As signs of vasculitis, US, MRI, and CT show a homogeneous arterial wall thickening, which is mostly concentric. PET displays increased FDG uptake in inflamed artery walls. US is recommended as the initial imaging modality in GCA. MRI and PET/CT may also detect vasculitis of temporal arteries. For TAK, MRI is recommended as the first imaging modality as it provides a good overview without radiation. Extracranial LVV can be confirmed by all four modalities. In addition, MRI and PET/CT provide consistent examination of the aorta and its branches. New techniques such as contrast-enhanced ultrasound, PET/MRI, and auxiliary methods such as “computer-assisted quantitative analysis” have emerged and need to be further validated.

Summary

Imaging has partly replaced histology for confirming LVV. Provided experience and adequate training, US, MRI, CT, or PET provide excellent diagnostic accuracy. Imaging results need to complement history and clinical examination. Ongoing studies are evaluating the role of imaging for monitoring and outcome measurement.

[The current place of non-invasive large-vessel imaging in the diagnosis and follow-up of giant cell arteritis]

Large vessel involvement in giant cell arteritis has long been described, although its right frequency and potential prognostic value have only been highlighted for two decades. Large vessel involvement not only is associated with a high incidence of late aortic aneurysms, but also might cause greater resistance to glucocorticoids and longer treatment duration, as well as worse late cardiovascular outcomes. These data were brought to our attention, thanks to substantial progress recently made in large vessel imaging. This relies on four single, often complementary, approaches of varying availability: colour Doppler ultrasound, contrast-enhanced computed tomography with angiography and, magnetic resonance imaging, which all demonstrate homogeneous circumferential wall thickening and describe structural changes; 18F-fluorodeoxyglucose positron emission tomography-computed tomography (PET/CT), which depicts wall inflammation and assesses many vascular territories in the same examination. In addition, integrated head-and-neck PET/CT can accurately and reliably diagnose cranial arteritis. All four procedures exhibit high diagnostic performance for a large vessel arteritis diagnosis so that the choice is left to the physician, depending on local practices and accessibility; the most important is to carry out the chosen modality without delay to avoid false or equivocal results, due to early vascular oedema changes as a result of high dose glucocorticoid treatment. Yet, ultrasound study of the superficial cranial and subclavian/axillary arteries remains a first line assessment aimed at strengthening and expediting the clinical diagnosis as well as raising suspicion of large-vessel involvement. In treated patients, vascular imaging results are poorly correlated with clinical-biological controlled disease so that it is strongly recommended not to renew imaging studies unless a large vessel relapse or complication is suspected. On the other hand, a structural monitoring of aorta following giant cell arteritis is mandatory, but uncertainties remain regarding the best procedural approach, timing of first control and spacing between controls. Individuals at greater risk of developing aortic complication, e.g. those with classic risk factors for aneurysm and/or visualised aortitis, should be monitored more closely.

Associated factors of poor treatment outcomes in patients with giant cell arteritis: clinical implication of large vessel lesions

Background

Relapses frequently occur in giant cell arteritis (GCA), and long-term glucocorticoid therapy is required. The identification of associated factors with poor treatment outcomes is important to decide the treatment algorithm of GCA.

Methods

We enrolled 139 newly diagnosed GCA patients treated with glucocorticoids between 2007 and 2014 in a retrospective, multi-center registry. Patients were diagnosed with temporal artery biopsy, 1990 American College of Rheumatology classification criteria, or large vessel lesions (LVLs) detected by imaging based on the modified classification criteria. Poor treatment outcomes (non-achievement of clinical remission by week 24 or relapse during 52 weeks) were evaluated. Clinical remission was defined as the absence of clinical signs and symptoms in cranial and large vessel areas, polymyalgia rheumatica (PMR), and elevation of C-reactive protein (CRP) levels. A patient was determined to have a relapse if he/she had either one of the signs and symptoms that newly appeared or worsened after achieving clinical remission. Re-elevation of CRP without clinical manifestations was considered as a relapse if other causes such as infection were excluded and the treatment was intensified. Associated factors with poor treatment outcomes were analyzed by using the Cox proportional hazard model.

Results

Cranial lesions, PMR, and LVLs were detected in 77.7%, 41.7%, and 52.5% of the enrolled patients, respectively. Treatment outcomes were evaluated in 119 newly diagnosed patients who were observed for 24 weeks or longer. The mean initial dose of prednisolone was 0.76 mg/kg/day, and 29.4% received any concomitant immunosuppressive drugs at baseline. Overall, 41 (34.5%) of the 119 patients had poor treatment outcomes; 13 did not achieve clinical remission by week 24, and 28 had a relapse after achieving clinical remission. Cumulative rates of the events of poor treatment outcomes in patients with and without LVLs were 47.5% and 17.7%, respectively. A multivariable model showed the presence of LVLs at baseline was significantly associated with poor treatment outcomes (adjusted hazard ratio [HR] 3.54, 95% CI 1.52–8.24, p = 0.003). Cranial lesions and PMR did not increase the risk of poor treatment outcomes.

Conclusion

The initial treatment intensity in the treatment algorithm of GCA could be determined based upon the presence or absence of LVLs detected by imaging at baseline.

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.

Segmental arterial mediolysis (SAM): Systematic review and analysis of 143 cases

Segmental arterial mediolysis (SAM) is a rare but serious nonatherosclerotic, noninflammatory vasculopathy of unknown etiology that often results in dissection, aneurysm, occlusion, or stenosis of, primarily, the abdominal arteries. Current literature lacks consensus on diagnostic criteria and management options for SAM. This review summarizes 143 cases and aims to advance appropriate recognition and management of SAM. Literature review of all relevant SAM case studies from 2005 to 2018 yielded 126 individual SAM cases from 66 reports. We identified 17 additional SAM cases from our center, bringing our analysis to 143 patients. Patients with SAM were most commonly men (68%) in their 60s. Hypertension (43%), tobacco use (12%), and hyperlipidemia (12%) were common comorbidities. Abdominal pain (80%) and intraabdominal bleeding (50%) were the most common presenting symptoms. Computed tomography was the most frequently used imaging method (78%), and histology was available in 44% of cases. The most commonly affected vessels were the superior mesenteric (53%), hepatic (45%), celiac (36%), renal (26%), and splenic (25%) arteries with aneurysm (76%), dissection (61%), and arterial rupture (46%). Treatments included coil embolization (28%), abdominal organ surgery (24%), open arterial repair (21%), and medical management (20%). Case-specific treatment modalities yielded symptom relief in the vast majority (91%) of patients, with a mortality rate of 7%.

[Imaging diagnostics in large vessel vasculitis]

Imaging procedures have become an important diagnostic tool in vasculitis. In large vessel vasculitides, such as giant-cell arteritis (GCA) and Takayasu arteritis, ultrasound, magnetic resonance imaging (MRI), computed tomography (CT) and 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can depict specific abnormalities of the arterial wall. A clinically suspected diagnosis can be confirmed by imaging if performed by a trained specialist using appropriate equipment, without histological investigations. Ultrasound, MRI and CT show a homogeneous, concentric thickening of the arterial wall and PET can detect increased glucose metabolism of the arterial wall. Ultrasound is the method of choice, especially in predominantly cranial GCA. Imaging should be performed before or within the first few days of glucocorticoid treatment as the PET findings of all arteries as well as ultrasound and MRI findings in temporal arteries normalize quickly with treatment. A planned imaging examination must not delay initiation of glucocorticoid treatment.

Endovascular biopsy in Takayasu arteritis

Takayasu arteritis is a chronic inflammatory arteriopathy of the large vessels, mainly the aortic arch and its branches. The disease progression varies, ranging from a rapid progression to quiescence reached within 2 years. The activity of the disease is evaluated by biochemical markers, but at times, there is a discrepancy between the clinical picture and biochemical markers. Histopathology helps in assessing the disease activity, but it is not included in the antemortem diagnosis because of the invasiveness of the procedure and the availability of noninvasive vascular imaging. However, it may be performed simultaneously with angioplasty. Here we present a case of endovascular aortic biopsy conducted to detect active inflammation in the aortic wall.

Glucocorticoid Dosages and Acute-Phase Reactant Levels at Giant Cell Arteritis Flare in a Randomized Trial of Tocilizumab

Objective

This study was undertaken to evaluate glucocorticoid dosages and serologic findings in patients with giant cell arteritis (GCA) flares.

Methods

Patients with GCA were randomly assigned to receive double‐blind dosing with either subcutaneous tocilizumab (TCZ) 162 mg weekly plus 26‐week prednisone taper (TCZ‐QW + Pred‐26), every‐other‐week TCZ plus 26‐week prednisone taper (TCZ‐Q2W + Pred‐26), placebo plus 26‐week prednisone taper (PBO + Pred‐26), or placebo plus 52‐week prednisone taper (PBO + Pred‐52). Outcome measures were prednisone dosage, C‐reactive protein (CRP) level, and erythrocyte sedimentation rate (ESR) at the time of flare.

Results

One hundred patients received TCZ‐QW + Pred‐26, 49 received TCZ‐Q2W + Pred‐26, 50 received PBO + Pred‐26, and 51 received PBO + Pred‐52. Of the 149 TCZ‐treated patients, 36 (24%) experienced flare, 23 (64%) of whom were still receiving prednisone (median dosage 2.0 mg/day). Among 101 PBO + Pred–treated patients, 59 (58%) experienced flare, 45 (76%) of whom were receiving prednisone (median dosage 5.0 mg/day). Many flares occurred while patients were taking >10 mg/day prednisone: 9 (25%) in the TCZ groups and 13 (22%) in the placebo groups. Thirty‐three flares (92%) in TCZ‐treated groups and 20 (34%) in PBO + Pred–treated groups occurred with normal CRP levels. More than half of the PBO + Pred–treated patients had elevated CRP levels without flares. Benefits of the TCZ and prednisone combination over prednisone alone for remission induction were apparent by 8 weeks.

Conclusion

Most GCA flares occurred while patients were still receiving prednisone. Acute‐phase reactant levels were not reliable indicators of flare in patients treated with TCZ plus prednisone or with prednisone alone. The addition of TCZ to prednisone facilitates earlier GCA control.

Advances in Therapies and Imaging for Systemic Vasculitis

Vasculitis is a systemic disease characterized by immune-mediated injury of blood vessels. Current treatments for vasculitis, such as glucocorticoids and alkylating agents, are associated with significant side effects. Furthermore, the management of both small and large vessel vasculitis is challenging because of a lack of robust markers of disease activity. Recent research has advanced our understanding of the pathogenesis of both small and large vessel vasculitis, and this has led to the development of novel biologic therapies capable of targeting key cytokine and cellular effectors of the inflammatory cascade. In parallel, a diverse range of imaging modalities with the potential to monitor vessel inflammation are emerging. Continued expansion of combined structural and molecular imaging using positron emission tomography with computed tomography or magnetic resonance imaging may soon provide reliable longitudinal tracking of vascular inflammation. In addition, the emergence of radiotracers able to assess macrophage activation and immune checkpoint activity represents an exciting new frontier in imaging vascular inflammation. In the near future, these advances will allow more precise imaging of disease activity enabling clinicians to offer more targeted and individualized patient management.

The Role of Vascular Imaging to Advance Clinical Care and Research in Large-Vessel Vasculitis

Purpose of the Review

The two main forms of large-vessel vasculitis (LVV) are giant cell arteritis (GCA) and Takayasu's arteritis (TAK). Vascular imaging can characterize disease activity and disease extent in LVV. This review critically analyzes the clinical utility of vascular imaging in LVV and highlights how imaging may be incorporated into the management and study of these conditions.

Recent Findings

There are multiple imaging modalities available to assess LVV including ultrasonography, CT angiography (CTA), magnetic resonance angiography (MRA), and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET). As these techniques are refined, imaging may be increasingly useful to evaluate the cranial arteries and the aorta and its primary branches. In addition, vascular imaging may be useful to monitor disease activity and may have prognostic value to predict future clinical events.

Summary

There are strengths and weaknesses associated with vascular imaging that should be considered when evaluating patients with LVV. Vascular imaging will likely play an increasingly important role in the clinical management of patients and the conduct of research in LVV and may ultimately be incorporated as outcome measures in clinical trials in these conditions.

Vessel wall plasticity in large vessel giant cell arteritis: an ultrasound follow-up study

Objectives

To assess changes of arterial vessel wall morphology in large vessel GCA patients (LV-GCA) by repeated US.

Methods

Patients with LV-GCA on US examination were followed up 6, 12 and 24 months after diagnosis by US of the temporal, vertebral, carotid (common, internal, external), subclavian, axillary, femoral (deep, superficial and common) and popliteal arteries. Clinical and laboratory data were assessed at each visit. Vessel wall thickening was classified as moderate, marked or arteriosclerotic.

Results

A total of 42 patients (26 female) with a median age of 75 years at diagnosis had in median 2 (range 1–3) US follow-up exams. Twenty-eight had both LV and temporal artery involvement and 14 had LV-GCA only. The common carotid, subclavian, axillary, popliteal and/or superficial femoral artery were most commonly involved. Reduction of LV wall thickening occurred in 45% of patients during follow-up, corresponding to 71 of the 284 (25%) initially ‘vasculitic’ LV segments. In contrast, a reduction of vessel wall thickening in the temporal artery was found in 85% of patients. Of the LVs, the vertebral, axillary, subclavian and deep femoral arteries were most likely to improve. There was no difference in relapses or the received cumulative steroid dose between patients with or without a reduction of vessel wall thickening (temporal artery or LV) during follow-up.

Conclusion

Regression of wall thickening within the LV is significantly less common than in the temporal artery and irrespective of clinical remission. Morphological regression does not seem to be a useful predictor for relapses.

PET/MRI in Infection and Inflammation

Hybrid positron emission tomography/magnetic resonance imaging (PET/MR) systems are now more and more available for clinical use. PET/MR combines the unique features of MR including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most of the evidence of the potential clinical utility of PET/MRI is available for neuroimaging. Other areas, where PET/MR can play a larger role include head and neck, upper abdominal, and pelvic tumours. Although the role of PET/MR in infection and inflammation of the cardiovascular system and in musculoskeletal applications are promising, these areas of clinical investigation are still in the early phase and it may be a little longer before these areas reach their full potential in clinical practice. In this review, we outline the potential of hybrid PET/MR for imaging infection and inflammation. A background to the main radiopharmaceuticals and some technical considerations are also included.

Novel Angiographic Scores for evaluation of Large Vessel Vasculitis

Arterial involvement is the cardinal feature of large-vessel vasculitis (LVV) and prevention of disease progression is the principal therapeutic goal. However, development of tools for its evaluation represents a major unmet need. To address this, a widely-applicable imaging tool for LVV, analysing arterial involvement in 17 arterial territories, has been developed and validated. Individual stenosis and dilation scores were generated and combined in a composite score. The methodology was validated cross-sectionally and longitudinally in 131 patients, 96 Takayasu arteritis (TA), 35 large-vessel giant-cell arteritis (LV-GCA). In total, 4420 arterial segments from 260 imaging studies were evaluated. The new scores allowed quantitative grading of LVV arterial involvement with high consistency, revealing inter-patient differences. TA had higher stenosis and composite scores and lower dilation scores than LV-GCA. Baseline stenotic and composite scores reflected arterial damage rather than disease-activity. Longitudinal changes in all three scores correlated with disease activity and mirrored arterial disease evolution, reflecting both progressive injury and lesion improvement. Increases ≥1 in any score were specific for arterial disease progression. The scores objectively quantify arterial involvement in LVV, providing precise definition of disease phenotype and evolution. We propose that they represent novel vascular outcome measures essential for future clinical trials.

Aortic dilatation in patients with large vessel vasculitis: A longitudinal case control study using PET/CT

OBJECTIVE

To evaluate aortic diameter and predictors of aortic dilatation using ¹⁸FDG-PET/CT in a longitudinally followed cohort of patients with large vessel vasculitis (LVV) compared with controls.

METHODS

All consecutive patients with LVV who underwent at least 2 PET/CT scans between January 2008 and May 2015 were included. The first and last PET/CT study was evaluated by a radiologist and a nuclear medicine physician. Diameter and FDG uptake of the aorta was measured at 4 different levels: ascending, descending thoracic, suprarenal and infrarenal abdominal aorta. Twenty-nine age- and sex-matched patients with lymphoma who underwent at least 2 PET/CT scans in the same time interval were selected as controls.

RESULTS

93 patients with LVV were included in the study. In the time interval between first and last PET/CT study (median time 31 months), the diameter of the ascending, descending thoracic and suprarenal abdominal aorta significantly increased in LVV patients but not in controls. At last PET/CT, patients with LVV compared with controls had higher diameter of ascending [35.41 (5.54) vs 32.97 (4.11) mm, p = 0.029], descending thoracic [28.42 (4.82) vs 25.72 (3.55) mm, p = 0.007] and suprarenal abdominal aorta, mean [25.34 (7.01) vs 22.16 (3.26) mm, p = 0.005] and more frequently had aortic dilatation [19% vs 3%, p = 0.023]. Significant predictors of aortic dilatation were male sex [OR 7.27, p = 0.001] and, only for GCA, hypertension [OR 6.30, p = 0.031]. Finally, GCA patients with aortic FDG uptake grade 3 at first PET/CT, compared to those with aortic FDG uptake ≤2, had significantly higher aortic diameter.

CONCLUSIONS

Patients with LVV are at increased risk of aortic dilatation compared with age- and sex-matched controls. Significant predictors of aortic dilatation are male sex and, only for GCA, hypertension. GCA patients with aortic FDG uptake grade 3 are at increased risk of aortic dilatation.

Investigations in systemic vasculitis - The role of imaging

Imaging plays an increasing role for confirming a suspected diagnosis of giant cell arteritis (GCA) or Takayasu arteritis (TAK). Ultrasound, magnetic resonance imaging (MRI), and computed tomography demonstrate a homogeneous, most commonly concentric, arterial wall thickening. 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET) displays increased FDG uptake of inflamed artery walls delineating increased metabolism. Ultrasound and MRI are recommended to be the initial imaging modalities in cranial GCA and TAK, respectively. Extracranial disease can be confirmed by all four modalities, particularly by PET in case of inflammation of unknown origin. If the diagnosis remains uncertain, additional investigations including biopsy and/or additional imaging are recommended. Imaging should be performed by a trained specialist using appropriate operational procedures and settings with appropriate equipment. Further research is necessary on the role of imaging for disease monitoring. This review will discuss advantages and disadvantages of imaging modalities in the diagnosis of vasculitis.

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.

Giant cell arteritis: beyond temporal artery biopsy and steroids

Giant cell arteritis is the most common primary vasculitis of the elderly. The acute complications of untreated giant cell arteritis, such as vision loss or occasionally stroke, can be devastating. The diagnosis is, however, not altogether straightforward due to variable sensitivities of the temporal artery biopsy as a reference diagnostic test. In this review, we discuss the increasing role of imaging in the diagnosis of giant cell arteritis. Glucocorticoid treatment is the backbone of therapy, but it is associated with significant adverse effects. A less toxic alternative is required. Conventional and novel immunosuppressive agents have only demonstrated modest effects in a subgroup of steroid refractory Giant cell arteritis due to the different arms of the immune system at play. However, recently a study of interleukin-6 blockade demonstrated benefits of giant cell arteritis. The current status of these immunosuppressive agents and novel therapies are also discussed in this review.