Comparison of temporal artery ultrasound versus biopsy in the diagnosis of giant cell arteritis

Multimodality Imaging in Cranial Giant Cell Arteritis: First Experience with High-Resolution T1-Weighted 3D Black Blood without Contrast Enhancement Magnetic Resonance Imaging

In order to support or refute the clinical suspicion of cranial giant cell arteritis (GCA), a supplemental imaging modality is often required. High-resolution black blood Magnetic Resonance Imaging (BB MRI) techniques with contrast enhancement can visualize artery wall inflammation in GCA. We compared findings on BB MRI without contrast enhancement with findings on 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/low-dose computed tomography (2-[18F]FDG PET/CT) in ten patients suspected of having GCA and in five control subjects who had a 2-[18F]FDG PET/CT performed as a routine control for malignant melanoma. BB MRI was consistent with 2-[18F]FDG PET/CT in 10 out of 10 cases in the group with suspected GCA. In four out of five cases in the control group, the BB MRI was consistent with 2-[18F]FDG PET/CT. In this small population, BB MRI without contrast enhancement shows promising performance in the diagnosis of GCA, and might be an applicable imaging modality in patients.

[Imaging of large vessel vasculitis]

Giant cell arteritis (GCA) and Takayasu arteritis (TAK) are the most important primary large vessel vasculitides. A rapid and reliable confirmation of the diagnosis is necessary to prevent ischemic complications. Patients with extracranial GCA and TAK often present with unspecific symptoms. Since 2018 the EULAR has recommended imaging as an alternative to histology for confirming the diagnosis. Ultrasound is particularly recommended as the primary imaging modality for cranial GCA. Alternatively, MRI and PET can be used for the diagnostics of temporal arteritis. Ultrasound is also valuable for extracranial GCA, alternatively MRI, CT or PET-CT can be used. This review discusses the current status of imaging techniques in large vessel vasculitis as well as the advantages and disadvantages. The focus is on ultrasound, which is increasingly being used as the primary diagnostic modality due to its excellent diagnostic quality, wide availability, noninvasiveness, and patient friendliness. Technical aspects, prerequisites, and normal and pathological findings are also presented. Finally, an outlook is given on promising new developments, such as scores for evaluating disease progression and contrast-enhanced ultrasound.

Imaging in diagnosis, monitoring and outcome prediction of large vessel vasculitis: a systematic literature review and meta-analysis informing the 2023 update of the EULAR recommendations

OBJECTIVES

To update the evidence on imaging for diagnosis, monitoring and outcome prediction in large vessel vasculitis (LVV) to inform the 2023 update of the European Alliance of Associations for Rheumatology recommendations on imaging in LVV.

METHODS

Systematic literature review (SLR) (2017-2022) including prospective cohort and cross-sectional studies (>20 participants) on diagnostic, monitoring, outcome prediction and technical aspects of LVV imaging. Diagnostic accuracy data were meta-analysed in combination with data from an earlier (2017) SLR.

RESULTS

The update retrieved 38 studies, giving a total of 81 studies when combined with the 2017 SLR. For giant cell arteritis (GCA), and taking clinical diagnosis as a reference standard, low risk of bias (RoB) studies yielded pooled sensitivities and specificities (95% CI) of 88% (82% to 92%) and 96% (95% CI 86% to 99%) for ultrasound (n=8 studies), 81% (95% CI 71% to 89%) and 98% (95% CI 89% to 100%) for MRI (n=3) and 76% (95% CI 67% to 83%) and 95% (95% CI 71% to 99%) for fluorodeoxyglucose positron emission tomography (FDG-PET, n=4), respectively. Compared with studies assessing cranial arteries only, low RoB studies with ultrasound assessing both cranial and extracranial arteries revealed a higher sensitivity (93% (95% CI 88% to 96%) vs 80% (95% CI 71% to 87%)) with comparable specificity (94% (95% CI 83% to 98%) vs 97% (95% CI 71% to 100%)). No new studies on diagnostic imaging for Takayasu arteritis (TAK) were found. Some monitoring studies in GCA or TAK reported associations of imaging with clinical signs of inflammation. No evidence was found to determine whether imaging severity might predict worse clinical outcomes.

CONCLUSION

Ultrasound, MRI and FDG-PET revealed a good performance for the diagnosis of GCA. Cranial and extracranial vascular ultrasound had a higher pooled sensitivity with similar specificity compared with limited cranial ultrasound.

Is Erythrocyte Sedimentation Rate Necessary for the Initial Diagnosis of Giant Cell Arteritis?

Giant cell arteritis (GCA) is an ophthalmological emergency that can be difficult to diagnose and prompt treatment is vital. We investigated the sequential diagnostic value for patients with suspected GCA using three biochemical measures as they arrive to the clinician: first, platelet count, then C-reactive protein (CRP), and lastly, erythrocyte sedimentation rate (ESR). This retrospective cross-sectional study of consecutive patients with suspected GCA investigated platelet count, CRP, and ESR using diagnostic test accuracy statistics and odds ratios (ORs) in a sequential fashion. The diagnosis was established by experts at follow-up, considering clinical findings and tests including temporal artery biopsy. A total of 94 patients were included, of which 37 (40%) were diagnosed with GCA. Compared with those without GCA, patients with GCA had a higher platelet count (p < 0.001), CRP (p < 0.001), and ESR (p < 0.001). Platelet count demonstrated a low sensitivity (38%) and high specificity (88%); CRP, a high sensitivity (86%) and low specificity (56%); routine ESR, a high sensitivity (89%) and low specificity (47%); and age-adjusted ESR, a moderate sensitivity (65%) and moderate specificity (65%). Sequential analysis revealed that ESR did not provide additional value in evaluating risk of GCA. Initial biochemical evaluation can be based on platelet count and CRP, without waiting for ESR, which allows faster initial decision-making in GCA.

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

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

Optical Coherence Tomography of Peripapillary Vessels in Giant Cell Arteritis and Ischaemic Ocular Disease

With normal retinal blood flow, cross-sectional optical coherence tomography (OCT) of retinal vessels shows a structured intravascular reflectivity profile, resembling a 'figure-of-8'. Altered profiles have been reported in vascular occlusive and haematological diseases. Giant cell arteritis (GCA) can cause visual loss, usually due to anterior ischaemic optic neuropathy (AION) or retinal artery occlusion. Our aim was to extend the assessment of OCT vascular profiles to patients with suspected GCA and to determine if any abnormalities were related to GCA per se or to ischaemic ocular conditions. This nested retrospective study included 61 eyes of 31 patients (13 with GCA). Six eyes had arteritic and seven eyes non-arteritic AION, three eyes had non-arteritic retinal artery occlusion, 11 eyes had other ocular conditions and 34 were unaffected control eyes. For each eye the appearance of structured intravascular profiles on peripapillary OCT was graded as present, partial, absent or uncertain. Non-presence of structured intravascular profiles was more frequent in AION and retinal artery occlusion than in other ocular conditions or unaffected eyes (Fisher's test, p = .0047). Based on follow-up of 25 eyes, reflectivity profiles normalised in three out of four eyes after 85 (35-245) days. Vessel profiles were not associated with GCA (p = .32) and were similar in arteritic and non-arteritic AION (p = .66). In conclusion, absence of structured intravascular reflectivity profiles may be a marker of acute ischaemia in the anterior optic nerve or inner retina. However, it did not seem specific for GCA. The prognostic value warrants further studies.

An update on the clinical approach to giant cell arteritis

Recent national and international guidance from rheumatology societies have reflected the advances in evidence for both the investigation and management of giant cell arteritis. Cranial ultrasound reduces diagnostic delay and improves clinical outcomes. Immediate high-dose glucocorticoids remain the standard treatment for giant cell arteritis. Randomised controlled trial evidence using tocilizumab, an interleukin-6 receptor antagonist, has been shown to have good clinical efficacy with glucocorticoid sparing effects. Overall patient outcomes appear to be improved by formalising pathways for diagnosis to include clinical experts' opinion early in decision making.

Giant Cell Arteritis: Updates and Controversies

Abstract

Giant cell arteritis (GCA) is a systemic granulomatous vasculitis affecting the medium and large-size arteries, and may present with a range of ophthalmic findings. This review will cover GCA epidemiology, pathophysiology, clinical presentation, diagnostic workup, and treatment.

Epidemiology and Pathophysiology

GCA is commonly found in elderly patients and individuals of Scandinavian descent. Recent publications suggest it may be more common in African Americans and Hispanics than previously thought. It is very rare in Asian and Middle-Eastern populations, and there is little data regarding African populations. Genetic studies have identified increased risk associated with HLA-DRB1*04. Rather than a response to a specific antigen such as varicella zoster virus, current immunology research suggests that GCA results from changes associated with the aging immune system.

Clinical presentation to Ophthalmology

Arteritic anterior ischemic optic neuropathy is the most common ophthalmic manifestation of GCA, but central or branch retinal artery occlusion, ophthalmic artery occlusion, cranial neuropathies causing diplopia, and more rarely anterior segment ischemia and anisocoria may also occur. Clinical testing including visual field testing, OCT, OCT-A, ICG and fluorescein angiography can be helpful in suggesting a diagnosis in addition to the clinical exam.

Diagnostic Workup

GCA is ultimately a clinical diagnosis, but it is usually supported with lab results, pathology, and/or imaging. Temporal artery biopsy (TAB) remains the gold standard diagnostic test although its sensitivity is debated and practice patterns still vary with respect to sample length and whether unilateral or simultaneous bilateral biopsies are performed. Some studies have reported higher sensitivity of ultrasounds over TAB, with added benefits of time efficiency and cost effectiveness, promoting the diagnostic use of ultrasounds. MRI and even PET CT protocols offer additional options for less invasive diagnostic testing.

Treatment

Vision-threatening GCA is treated acutely with emergent admission for intravenous methylprednisolone, and long-term high dose oral corticosteroids remain the standard of care, despite common and sometimes serious side effects. The use of steroid-sparing alternatives such as tocilizumab is becoming more common and additional agents are being investigated.