Characterization of Extracranial Giant Cell Arteritis with Intracranial Involvement and its Rapidly Progressive Subtype

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.

Cytokine producing B-cells and their capability to polarize macrophages in giant cell arteritis

OBJECTIVE

The lack of disease-specific autoantibodies in giant cell arteritis (GCA) suggests an alternative role for B-cells readily detected in the inflamed arteries. Here we study the cytokine profile of tissue infiltrated and peripheral blood B-cells of patients with GCA. Moreover, we investigate the macrophage skewing capability of B-cell-derived cytokines.

METHODS

The presence of various cytokines in B-cell areas in temporal artery (n = 11) and aorta (n = 10) was identified by immunohistochemistry. PBMCs of patients with GCA (n = 11) and polymyalgia rheumatica (n = 10), and 14 age- and sex-matched healthy controls (HC) were stimulated, followed by flow cytometry for cytokine expression in B-cells. The skewing potential of B-cell-derived cytokines (n = 6 for GCA and HC) on macrophages was studied in vitro.

RESULTS

The presence of IL-6, GM-CSF, TNFα, IFNγ, LTβ and IL-10 was documented in B-cells and B-cell rich areas of GCA arteries. In vitro, B-cell-derived cytokines (from both GCA and HC) skewed macrophages towards a pro-inflammatory phenotype with enhanced expression of IL-6, IL-1β, TNFα, IL-23, YKL-40 and MMP-9. In vitro stimulated peripheral blood B-cells from treatment-naïve GCA patients showed an enhanced frequency of IL-6+ and TNFα+IL-6+ B-cells compared to HCs. This difference was no longer detected in treatment-induced remission. Erythrocyte sedimentation rate positively correlated with IL-6+TNFα+ B-cells.

CONCLUSION

B-cells are capable of producing cytokines and steering macrophages towards a pro-inflammatory phenotype. Although the capacity of B-cells in skewing macrophages is not GCA specific, these data support a cytokine-mediated role for B-cells in GCA and provide grounds for B-cell targeted therapy in GCA.

Giant cell arteritis-related cerebrovascular ischemic events: a French retrospective study of 271 patients, systematic review of the literature and meta-analysis

BACKGROUND

Cerebrovascular ischemic events (CIE) are among the most severe complications of giant cell arteritis (GCA). Heterogeneity between different studies in the definition of GCA-related CIE leads to uncertainty regarding their real prevalence. The aim of our study was to evaluate the prevalence and describe the characteristics of GCA-related CIE in a well-phenotyped cohort completed by a meta-analysis of the existing literature.

METHODS

In this retrospective study performed in the Lille University Hospital, all consecutive patients with GCA according to American College of Rheumatology (ACR) diagnostic criteria were included from January 1, 2010, to December 31, 2020. A systematic review of the literature using MEDLINE and EMBASE was performed. Cohort studies of unselected GCA patients reporting CIE were included in the meta-analysis. We calculated the pooled summary estimate of GCA-related CIE prevalence.

RESULTS

A total of 271 GCA patients (89 males, mean age 72 ± 9 years) were included in the study. Among them, 14 (5.2%) presented with GCA-related CIE including 8 in the vertebrobasilar territory, 5 in the carotid territory, and 1 patient having multifocal ischemic and hemorrhagic strokes related to intra-cranial vasculitis. Fourteen studies were included in the meta-analysis, representing a total population of 3553 patients. The pooled prevalence of GCA-related CIE was 4% (95% CI 3-6, I2 = 68%). Lower body mass index (BMI), vertebral artery thrombosis on Doppler US (17% vs 0.8%, p = 0.012), vertebral arteries involvement (50% vs 3.4%, p < 0.001) and intracranial arteries involvement (50% vs 1.8%, p < 0.001) on computed tomography angiography (CTA) and/or magnetic resonance angiography (MRA), and axillary arteries involvement on positron emission computed tomography (PET/CT) (55% vs 20%, p = 0.016) were more frequent in GCA patients with CIE in our population.

CONCLUSIONS

The pooled prevalence of GCA-related CIE was 4%. Our cohort identified an association between GCA-related CIE, lower BMI, and vertebral, intracranial, and axillary arteries involvement on various imaging modalities.

Giant cell arteritis with vertebral artery involvement-baseline characteristics and follow-up of a monocentric patient cohort

Vertebral artery (VA) involvement in giant cell arteritis (GCA) has rarely been reported. We aimed to evaluate the prevalence, patients' characteristics, and immunotherapies used in patients with GCA and VA involvement at diagnosis and 1 year follow-up, retrospectively including patients being diagnosed between January 2011 and March 2021 in our department. Clinical features, laboratory data, VA imaging, immunotherapy, and 1 year follow-up data were analyzed. Baseline characteristics were compared to GCA patients without VA involvement. Among all 77 cases with GCA, 29 patients (37.7%) had VA involvement, as diagnosed by imaging and/or clinical signs and symptoms. Gender distribution and erythrocyte sedimentation rate (ESR) were significantly different in the groups with and without VA involvement, with more women being affected (38/48 patients, 79.2%) and a significantly higher median ESR in patients without VA involvement (62 vs. 46 mm/h; p = 0.012). MRI and/or CT showed vertebrobasilar stroke at GCA diagnosis in 11 cases. 67/77 patients (87.0%) received high-dose intravenous glucocorticosteroids (GCs) at diagnosis, followed by oral tapering. Six patients were treated with methotrexate (MTX), one with rituximab, and five with tocilizumab (TCZ). 2/5 TCZ patients achieved clinical remission after 1 year, vertebrobasilar stroke within the first year occurred in 2/5 patients. Diagnosis of VA involvement might be underrecognized in GCA patients. VA imaging should be performed in elderly patients with vertebrobasilar stroke presenting with GCA symptoms, not to miss GCA as the etiology of stroke. Efficacy of immunotherapies in GCA with VA affection and long-term outcomes need to be investigated further.

Diagnostic and therapeutic approach to adult central nervous system vasculitis

The clinical manifestations of central nervous system (CNS) vasculitis are highly variable. In the absence of a positive CNS biopsy, CNS vasculitis is particularly suspected when markers of both vascular disease and inflammation are present. To facilitate the clinical and therapeutic approach to this rare condition, CNS vasculitis can be classified according to the size of the involved vessels. Vascular imaging is used to identify medium vessel disease. Small vessel disease can only be diagnosed with a CNS biopsy. Medium vessel vasculitis usually presents with focal neurological signs, while small vessel vasculitis more often leads to cognitive deficits, altered level of consciousness and seizures. Markers of CNS inflammation include cerebrospinal fluid pleocytosis or elevated protein levels, and vessel wall, parenchymal or leptomeningeal enhancement. The broad range of differential diagnoses of CNS vasculitis can be narrowed based on the disease subtype. Common mimickers of medium vessel vasculitis include intracranial atherosclerosis and reversible cerebral vasoconstriction syndrome. The diagnostic workup aims to answer two questions: is the neurological presentation secondary to a vasculitic process, and if so, is the vasculitis primary (i.e., primary angiitis of the CNS) or secondary (e.g., to a systemic vasculitis, connective tissue disorder, infection, malignancy or drug use)? In primary angiitis of the CNS, glucocorticoids and cyclophosphamide are most often used for induction therapy, but rituximab may be an alternative. Based on the available evidence, all patients should receive maintenance immunosuppression. A multidisciplinary approach is necessary to ensure an accurate and timely diagnosis and to improve outcomes for patients with this potentially devastating condition.

Spectrum of Large and Medium Vessel Vasculitis in Adults: Primary Vasculitides, Arthritides, Connective Tissue, and Fibroinflammatory Diseases

Purpose of Review

To provide a comprehensive overview of the spectrum of large and medium vessel vasculitis in adults with primary vasculitides, arthritides, connective tissue, and fibroinflammatory diseases as well as vasculitis mimics, for an efficient differential diagnosis and initial diagnostic approach.

Recent Findings

Imaging has had a tremendous impact on the diagnosis of medium to large vessel vasculitis, now often replacing histopathologic confirmation and identifying new disease manifestations (e.g., intracranial disease in giant cell arteritis; vascular manifestations of IgG4-related disease). Novel diseases or syndromes involving blood vessels have been described (e.g., VEXAS-Syndrome with polychondritis). The use of the terms “medium” or “large” vessel varies considerably between medical specialties.

Summary

The differential diagnosis of large and medium vessel vasculitis is becoming increasingly complex as new entities or disease manifestations of known inflammatory rheumatic diseases are regularly identified. A more precise and widely recognized definition of the vessel sizes would make future research more comparable.

Giant cell arteritis-related stroke in a large inception cohort: A comparative study

OBJECTIVE

Stroke caused by giant cell arteritis (GCA) is a rare but devastating condition and early recognition is of critical importance. The features of GCA-related stroke were compared with those of GCA without stroke and atherosclerosis-related or embolic stroke with the aim of more readily diagnosing GCA.

METHODS

The study group consisted of 19 patients who experienced GCA-related strokes within an inception cohort (1982-2021) of GCA from the internal medicine department, and the control groups each consisted of 541 GCA patients without a stroke and 40 consecutive patients > 50 years of age with usual first ever stroke from the neurology department of a French university hospital. Clinical, laboratory, and imaging findings associated with GCA related-stroke were determined using logistic regression analyses. Early survival curves were estimated using the Kaplan-Meier method and compared using the log rank test.

RESULTS

Amongst 560 patients included in the inception cohort, 19 (3.4%) developed GCA-related stroke. GCA-related stroke patients had more comorbid conditions (p = 0.03) and aortitis on imaging (p = 0.02), but less headache (p < 0.01) and scalp tenderness (p = 0.01). Multivariate logistic regression analysis showed that absence of involvement of the anterior circulation (OR = 0.1 - CI: 0.01-0.5), external carotid ultrasound (ECU) abnormalities (OR = 8.1 - CI: 1.3-73.9), and C-reactive protein (CRP) levels > 3 mg/dL (OR = 15.4 - CI: 1.9-197.1) were independently associated with GCA-related stroke. Early survival of GCA-related stroke patients was significantly decreased compared with control stroke patients (p = 0.02) and GCA patients without stroke (p < 0.001).

CONCLUSIONS

The location of stroke and assessment of ECU results and CRP level could help improve the prognosis of GCA-related stroke by bringing this condition to the clinician's attention more quickly, thus shortening diagnostic delay.