Tissue and Serum Angiogenic Activity Is Associated With Low Prevalence of Ischemic Complications in Patients With Giant-Cell Arteritis

High-frequency ultrasound with superb microvascular imaging: a potential tool for ultrasound assessment in patients with giant cell arteritis

Objective

The objective of this study was 2-fold: first, to evaluate whether superb microvascular imaging (SMI) could be used to visualize neovascularization in temporal arteries, and, second, to evaluate the diagnostic performance of high frequency ultrasound with SMI using an extended protocol in patients with suspected giant cell arteritis (GCA).

Methods

This retrospective study comprised 120 patients consecutively examined with an extended CDU protocol (temporal, facial, axillary, subclavian, brachiocephalic, and carotid arteries) between 2020 and 2022. Of all patients, 107 had no previous GCA diagnosis and 13 had a previous GCA diagnosis. SMI was used to evaluate neovascularization in the temporal arteries. Arteritis were characterized as low- or medium-echogenic, homogeneous wall thickening, with or without a positive compression sign in the temporal arteries. The Halo count, i.e., the number of temporal and axillary artery segments with signs of arteritis, was evaluated. The reference was clinically diagnosed GCA confirmed after ≥6-month follow-up.

Results

Of the eligible 107 patients with new suspected GCA, 33 (31%) received a clinical GCA diagnosis. Neovascularization was detected in 14 patients (43%). Patients with neovascularization displayed a higher halo count [median 6 (25th-75th percentile 4.75-7) vs. 3 (2-4-4), p = 0.005]. CDU of only the temporal arteries showed sensitivity and specificity (95% confidence intervals) of 94% (80-100%) and 100% (95-100%), respectively. The addition of extra-cranial arteries increased the sensitivity to 100%. Of the 13 patients investigated for suspected relapse, three had a clinically confirmed relapse. One of them displayed neovascularization together with other signs of inflammation.

Conclusions

We show for the first time that inflammatory neovascularization of the temporal arteries can be detected by SMI. Neovascularization is associated with a more-widespread cranial disease. The value of neovascularization should be further investigated, especially for the detection of GCA relapse.

Genetics of vasculitis

Systemic vasculitis encompasses a wide range of conditions characterized by varying degrees of inflammation in blood vessels. Although the etiology of vasculitis remains unclear, accumulated data suggest that it is triggered in genetically predisposed individuals by the concurrence of certain environmental factors. The importance of the genetic component has been consistently supported by evidence of familial aggregation, differential prevalence by ethnicity, and multiple genetic associations with disease susceptibility and severity reported in recent years. The strongest association signals in most vasculitides correspond to genetic variants within the HLA region, suggesting an important role of the immune system in its pathophysiology. However, each type of vasculitis has distinct defining HLA association markers, likely due to disease-specific differences in antigenic drivers. Furthermore, other genetic polymorphisms located outside the HLA region play an important role in susceptibility to different vasculitides. More recent research has assessed the shared genetic susceptibility evident across different vasculitides. Future studies should focus on the identification of genetic markers that can serve as reliable biomarkers for early diagnosis, prognosis, and treatment response in systemic vasculitis.

Histopathology reporting of temporal artery biopsy specimens for giant cell arteritis: results of a modified Delphi study

The temporal artery biopsy (TAB) is regarded as the gold-standard test in the diagnosis of giant cell arteritis (GCA). There is a lack of agreement among experienced pathologists regarding the diagnostic features and classification of inflammation observed in TAB sections in the diagnosis of GCA.

AIMS

The aim of this research study was to establish consensus on the key parameters which should be included in a standardised reporting proforma for TAB specimens. We specifically investigated factors pertaining to clinical information, specimen handling and microscopic pathological features.

METHODS

A modified Delphi process, comprising three survey rounds and three virtual consensus group meetings, was undertaken by 13 UK-based pathology or ophthalmology consultants, with a 100% response rate across the three rounds. Initial statements were formulated after a literature review and participants were asked to rate their agreement using a nine-point Likert scale. Consensus was defined a priori as an agreement of ≥70% and individual feedback was provided after each round, together with data on the distribution of group responses.

RESULTS

Overall, 67 statements reached consensus and 17 statements did not. The participants agreed on the core microscopic features to be included in a pathology report and felt that a proforma would facilitate consistent reporting practices.

CONCLUSIONS

Our work revealed uncertainty surrounding the correlation between clinical parameters (eg, laboratory markers of inflammation and steroid therapy duration) and microscopic findings, and we propose areas for future research.

Current Insights into Tissue Injury of Giant Cell Arteritis: From Acute Inflammatory Responses towards Inappropriate Tissue Remodeling

Giant cell arteritis (GCA) is an autoimmune disease affecting large vessels in patients over 50 years old. It is an exemplary model of a classic inflammatory disorder with IL-6 playing the leading role. The main comorbidities that may appear acutely or chronically are vascular occlusion leading to blindness and thoracic aorta aneurysm formation, respectively. The tissue inflammatory bulk is expressed as acute or chronic delayed-type hypersensitivity reactions, the latter being apparent by giant cell formation. The activated monocytes/macrophages are associated with pronounced Th1 and Th17 responses. B-cells and neutrophils also participate in the inflammatory lesion. However, the exact order of appearance and mechanistic interactions between cells are hindered by the lack of cellular and molecular information from early disease stages and accurate experimental models. Recently, senescent cells and neutrophil extracellular traps have been described in tissue lesions. These structures can remain in tissues for a prolonged period, potentially favoring inflammatory responses and tissue remodeling. In this review, current advances in GCA pathogenesis are discussed in different inflammatory phases. Through the description of these-often overlapping-phases, cells, molecules, and small lipid mediators with pathogenetic potential are described.

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.

The role of autoimmunity and autoinflammation in giant cell arteritis: A systematic literature review

Giant cell arteritis is the most common form of large vessel vasculitis and preferentially involves large and medium-sized arteries in patients over the age of 50. Aggressive wall inflammation, neoangiogenesis and consecutive remodeling processes are the hallmark of the disease. Though etiology is unknown, cellular and humoral immunopathological processes are well understood. Matrix metalloproteinase-9 mediated tissue infiltration occurs through lysis of basal membranes in adventitial vessels. CD4+ cells attain residency in immunoprotected niches, differentiate into vasculitogenic effector cells and enforce further leukotaxis. Signaling pathways involve the NOTCH1-Jagged1 pathway opening vessel infiltration, CD28 mediated T-cell overstimulation, lost PD-1/PD-L1 co-inhibition and JAK/STAT signaling in interferon dependent responses. From a humoral perspective, IL-6 represents a classical cytokine and potential Th-cell differentiator whereas interferon-γ (IFN- γ) has been shown to induce chemokine ligands. Current therapies involve glucocorticoids, tocilizumab and methotrexate application. However, new agents, most notably JAK/STAT inhibitors, PD-1 agonists and MMP-9 blocking substances, are being evaluated in ongoing clinical trials.

Carotid Artery Stenosis and Ischemic Strokes in Patients with Giant Cell Arteritis: A Characteristic Pattern-Literature Review and Case Report

Purpose  Ischemic stroke is a relatively rare complication of giant cell arteritis often accompanied by vessel stenosis. Our purpose was to compare the location of internal carotid artery stenosis in GCA patients by performing a literature review suggesting a specific and characteristic pattern. Methods  We performed a PubMed research including all articles and cited articles reporting cases and case series about giant cell arteritis patients with internal carotid artery stenosis and ischemic strokes. Results  In this case series 39 cases were included. We found a clear tendency of giant cell arteritis-related stenosis to be in the intracranial segments (35/39 (89.7%)). Only in 8/39 (20.5%) patients there was further involvement of extracranial segments. Many cases (27/39 [69.2%]) showed a bilateral involvement. Discussion  This literature review reveals a specific pattern of internal carotid artery involvement in patients with giant cell arteritis and ischemic strokes. To our knowledge this pattern has not been reported as a sign strongly pointing toward giant cell arteritis before. We have not found case reports mentioning other common types of vasculitis reporting this involvement pattern. Conclusion  Internal carotid artery stenosis and ischemic stroke is a rare complication in patients with giant cell arteritis. Considering the characteristic features of bilateral distal internal carotid artery stenosis giant cell arteritis should be suspected which potentially leads to an early diagnosis and immunotherapy.

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.

Stroke secondary to giant-cell arteritis: A literature review

Stroke is a leading cause of death and disability worldwide. In addition to the classical etiologies of stroke as atherosclerosis and cardioembolism there are many unusual, rare causes, which require a high level of clinical suspicion and further investigations for correct and early diagnosis and adequate treatment. Giant-cell arteritis or temporal arteritis, the most frequent vasculitis in the elderly population is one of the uncommon causes of stroke. In the setting of giant-cell arteritis, stroke more likely affects the vertebrobasilar territory and is the main cause of mortality. Duplex ultrasound examination is a routine investigation for stroke patients and may be key to the diagnosis if the classical hypoechoic ‘halo sign’ is recognized at the level of vertebral arteries. In this situation the ultrasound evaluation of temporal arteries and temporal artery biopsy are mandatory. The Giant-cell arteritis-related stroke is a rare condition; therefore, there are no evidence-based guidelines or standard recommendations for the treatment. In the present review, the main characteristics of giant-cell arteritis-related stroke are discussed.

A Distinct Macrophage Subset Mediating Tissue Destruction and Neovascularization in Giant Cell Arteritis: Implication of the YKL-40 - IL-13 Receptor α2 Axis

Objective

Macrophages mediate inflammation, angiogenesis, and tissue destruction in giant cell arteritis (GCA). Serum levels of the macrophage‐associated protein YKL‐40 (chitinase 3–like protein 1), previously linked to angiogenesis and tissue remodeling, remain elevated in GCA despite glucocorticoid treatment. This study was undertaken to investigate the contribution of YKL‐40 to vasculopathy in GCA.

Methods

Immunohistochemistry was performed on GCA temporal artery biopsy specimens (n = 12) and aortas (n = 10) for detection of YKL‐40, its receptor interleukin‐13 receptor α2 (IL‐13Rα2), macrophage markers PU.1 and CD206, and the tissue‐destructive protein matrix metalloproteinase 9 (MMP‐9). Ten noninflamed temporal artery biopsy specimens served as controls. In vitro experiments with granulocyte–macrophage colony‐stimulating factor (GM‐CSF)– or macrophage colony‐stimulating factor (M‐CSF)–skewed monocyte‐derived macrophages were conducted to study the dynamics of YKL‐40 production. Next, small interfering RNA–mediated knockdown of YKL‐40 in GM‐CSF–skewed macrophages was performed to study its effect on MMP‐9 production. Finally, the angiogenic potential of YKL‐40 was investigated by tube formation experiments using human microvascular endothelial cells (HMVECs).

Results

YKL‐40 was abundantly expressed by a CD206+MMP‐9+ macrophage subset in inflamed temporal arteries and aortas. GM‐CSF–skewed macrophages from GCA patients, but not healthy controls, released significantly higher levels of YKL‐40 compared to M‐CSF–skewed macrophages (P = 0.039). In inflamed temporal arteries, IL‐13Rα2 was expressed by macrophages and endothelial cells. Functionally, knockdown of YKL‐40 led to a 10–50% reduction in MMP‐9 production by macrophages, whereas exposure of HMVECS to YKL‐40 led to significantly increased tube formation.

Conclusion

In GCA, a GM‐CSF–skewed, CD206+MMP‐9+ macrophage subset expresses high levels of YKL‐40 which may stimulate tissue destruction and angiogenesis through IL‐13Rα2 signaling. Targeting YKL‐40 or GM‐CSF may inhibit macrophages that are currently insufficiently suppressed by glucocorticoids.

Clinical comparisons of patients with giant cell arteritis with versus without fever at onset

Objective

Giant cell arteritis (GCA) is the most common systemic vasculitis in individuals aged ≥50 years. Some patients with GCA who develop fever at onset without typical ischemic manifestations may be misdiagnosed with fever of unknown origin.

Methods

In the present study, we retrospectively evaluated the clinical records of patients with GCA. Patients with and without fever at onset were compared.

Results

This study included 91 patients with GCA, 55 of whom had fever at onset. The patients with fever at onset showed a lower frequency of jaw claudication and arthralgia and a higher percentage of constitutional symptoms than patients without fever. Additionally, their laboratory results revealed a lower percentage of positive anti-neutrophil cytoplasmic antibody. Furthermore, a lower proportion of affected intracranial vessels was found in patients with fever at onset. Finally, the proportion of biopsy-positive cases was higher in patients with than without fever at onset.

Conclusions

In this study, 60.4% of patients with GCA had fever at onset. Patients in this group usually had more severe inflammation with a potentially lower risk of ischemic accidents of the central nervous system than patients without fever at onset.

[Physiopathology of giant cell arteritis: From inflammation to vascular remodeling]

Giant cell arteritis (GCA) is a large-vessel vasculitis involving the aorta and its main branches, especially supra aortic branches. Although much progress has been made, the pathophysiology remains incompletely understood. An initial trigger, suspected of infectious origin, lead to the maturation and recruitment of dendritic cells (DC). The lack of migration of these DC allows the local recruitment of T-lymphocytes (LT). These LT- CD4⁺ polarize in Type 1 helper (Th1), Th17 but also Th9. A qualitative and quantitative deficit in regulatory T cells (Treg) is observed under the influence of IL-21 overproduction. In addition, an imbalance in the Th17/Treg balance is favored by IL-6. The secretion of IFN-γ, IL-17, IL-6, IL-33 is responsible for a sustained local inflammatory reaction that is organized around tertiary lymphoid follicles. Locally recruited macrophages secrete reactive forms of oxygen together with VEGF and PDGF. These growth factors, together with neurotrophins and endothelin contribute to increase the proliferation of vascular smooth muscle cells (VSMCs). The imbalance between matrix metalloproteases (MMP)-2, MMP-9 and MMP-14 and tissue inhibitors of metalloproteases (TIMP)-1 and TIMP-2 also contribute to the remodeling process occurring in the vessel wall. Finally, arterial neovascularization contribute to the perpetuation of lymphocyte recruitment. This persistent remodeling is sometimes complicated by ischemic events responsible for the initial severity of the disease.

Genetic Basis of Vasculitides with Neurologic Involvement

"Vasculitides are a heterogeneous group of inflammatory diseases of blood vessels in which genetic variation plays an important role in their susceptibility and clinical spectrum. Because of the use of novel technologies and the increase of the sample size of the study cohorts, the knowledge of the genetic background of vasculitides has considerably expanded during the last years. However, few insights have been obtained regarding the genetics underlying severe clinical phenotypes, such as those related to the nervous system. In this review the authors provide an updated overview of the genetic landscape behind vasculitis predisposition and development of neurologic manifestations."

Review: What Is the Current Evidence for Disease Subsets in Giant Cell Arteritis?

Giant cell arteritis (GCA) is an autoimmune vasculitis affecting large and medium‐sized arteries. Ample evidence indicates that GCA is a heterogeneous disease in terms of symptoms, immune pathology, and response to treatment. In the current review, we discuss the evidence for disease subsets in GCA. We describe clinical and immunologic characteristics that may impact the risk of cranial ischemic symptoms, relapse rates, and long‐term glucocorticoid requirements in patients with GCA. In addition, we discuss both proven and putative immunologic targets for therapy in patients with GCA who have an unfavorable prognosis. Finally, we provide recommendations for further research on disease subsets in GCA.

Pathogenesis of giant-cell arteritis: how targeted therapies are influencing our understanding of the mechanisms involved

GCA is a chronic granulomatous vasculitis that affects large- and medium-sized vessels. Both the innate and the adaptive immune system are thought to play an important role in the initial events of the pathogenesis of GCA. Amplification cascades are involved in the subsequent development and progression of the disease, resulting in vascular inflammation, remodelling and occlusion. The development of large-vessel vasculitis in genetically modified mice has provided some evidence regarding potential mechanisms that lead to vascular inflammation. However, the participation of specific mechanistic pathways in GCA has not been fully established because of the paucity and limitations of functional models. Treatment of GCA is evolving, and novel therapies are being incorporated into the GCA treatment landscape. In addition, to improve the management of GCA, targeted therapies are providing functional proof of concept of the relevance of particular pathogenic mechanisms in the development of GCA and in sustaining vascular inflammation.

Visual loss and other cranial ischaemic complications in giant cell arteritis

Giant cell arteritis (GCA) is the most common form of vasculitis in individuals aged 50 years and over. GCA typically affects large and medium-sized arteries, with a predilection for the extracranial branches of the carotid artery. Patients with GCA usually present with symptoms and signs that are directly related to the artery that is affected, with or without constitutional manifestations. The most dreaded complication of GCA is visual loss, which affects about one in six patients and is typically caused by arteritis of the ophthalmic branches of the internal carotid artery. Before the advent of glucocorticoid treatment, the prevalence of visual complications was high. Increasing awareness by physicians of the symptoms of GCA and advances in diagnostic techniques over the past twenty years have also contributed to a substantial decline in the frequency of permanent visual loss. Ischaemic brain lesions are less common than visual lesions, and mostly result from vasculitis of the extradural vertebral or carotid arteries. In the case of both the eye and the brain, ischaemic damage is thought to result from arterial stenosis or occlusion that occurs secondary to the inflammatory process. The inflammatory response at the onset of arteritis, its role as a predictor of complications and the role of traditional cardiovascular risk factors have been extensively investigated in the past decade. In this Review, the epidemiology, risk factors, clinical presentation and current therapeutic approach of GCA-related ischaemic events are discussed, with a particular emphasis on visual loss.

Is vascular endothelial growth factor a useful biomarker in giant cell arteritis?

Objectives

To assess the performance of circulating vascular endothelial growth factor (VEGF) levels as a tool for diagnosing giant cell arteritis (GCA) in a cohort of patients referred for assessment of suspected GCA.

Methods

We selected 298 patients recruited to the multicentre study Temporal Artery Biopsy versus Ultrasound in diagnosis of suspected GCA (TABUL). In a random subset of 26 biopsy-proven GCA cases and 26 controls, serum from weeks 0, 2 and 26 was analysed for VEGF concentration using ELISA. VEGF concentration at week 0 was used to generate a receiver-operating characteristic curve and thereby identify a cut-off for an abnormal result which was used to analyse the full patient cohort. Sections of paraffin-embedded temporal artery were stained by immunohistochemistry for VEGF.

Results

The mean (95% CI) VEGF concentration at week 0 was 873 pg/mL (631 to 1110) in 26 patients versus 476 pg/mL (328 to 625) in 26 controls (p=0.017). This difference was not observed at any other time point. The optimal cut-off of 713 pg/mL was applied to the whole patient cohort (n=298), yielding sensitivity of 32% and specificity of 85%. This was not improved by combination with any clinical parameters. When patients with biopsy-proven GCA were compared with controls, sensitivity was 58% and specificity remained 85%. Sections of biopsy from biopsy-positive GCA showed intense staining in the adventitia which was not seen in controls.

Conclusions

Serum VEGF concentration predicts biopsy positivity but is not useful for differentiating clinical cases of GCA from controls. Further studies into VEGF as a prognostic marker and therapeutic target are warranted.

Trial registration number

NCT00974883; Post-results.

The Expanding Role of Imaging in Systemic Vasculitis

Various imaging modalities, including color duplex ultrasonography, CT angiography, magnetic resonance angiography, and PET, are emerging as important aids to the diagnosis, staging, evaluation of disease activity and response to treatment in systemic vasculitis. Although large-vessel vasculitis is the main target of imaging, refinement and increasing accuracy of imaging modalities are also providing useful information in the evaluation of medium-vessel and small-vessel vasculitis.

Correlations between histopathological findings and clinical manifestations in biopsy-proven giant cell arteritis

OBJECTIVE

To correlate histopathological features of positive temporal artery biopsy (TAB) and clinical manifestations of the disease in a large single-center population-based cohort of patients with biopsy-proven giant cell arteritis (GCA).

METHODS

A pathologist with expertise in vasculitis and blinded to clinical data and final diagnosis reviewed all TABs performed for suspected GCA at our hospital between January 1986 and December 2013. Histopathologic features evaluated were: the severity of inflammation and intimal hyperplasia, both graded on a semiquantitative scale (mild = 1, moderate = 2, severe = 3), the presence of intraluminal acute thrombosis, calcifications, giant cells, fibrinoid necrosis and laminar necrosis.

RESULTS

274 patients had a final diagnosis of biopsy-proven GCA and were included in the study. Cranial ischemic events (CIEs) were observed in 161 (58.8%), visual manifestations in 79 (28.8%) and permanent (partial or complete) visual loss in 51 (18.6%) patients. Predictors for the development of CIEs were older age (OR = 1.057, 95% CI 1.019-1.097, p = 0.003), lower ESR values (OR = 0.990, 95% CI 0.981-0.999, p = 0.026) as well as the presence of giant cells (OR = 1.848, 95% CI 1.045-3.269, p = 0.035) and laminar necrosis at TAB (OR = 2.334, 95% CI 1.187-4.587, p = 0.014). Predictors for the development of permanent visual loss were lower CRP values (OR = 0.906, 95% CI 0.827-0.992, p = 0.033) and the presence of calcifications at TAB (OR = 3.672, 95% CI 1.479-9.121, p = 0.005). Fibrinoid necrosis was not observed in any of the TABs evaluated.

CONCLUSION

Pathological features of TAB may predict some manifestations of GCA. These findings may have implications for patients' management.

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

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

Venous Thromboembolism and Cerebrovascular Events in Patients with Giant Cell Arteritis: A Population-Based Retrospective Cohort Study

Objective

To investigate the incidence of venous thromboembolism (VTE) and cerebrovascular events in a community-based incidence cohort of patients with giant cell arteritis (GCA) compared to the general population.

Methods

A population-based inception cohort of patients with incident GCA between January 1, 1950 and December 31, 2009 in Olmsted County, Minnesota and a cohort of non-GCA subjects from the same population were assembled and followed until December 31, 2013. Confirmed VTE and cerebrovascular events were identified through direct medical record review.

Results

The study population included 244 patients with GCA with a mean ± SD age at diagnosis of 76.2 ± 8.2 years (79% women) and an average length of follow-up of 10.2 ± 6.8 years. Compared to non-GCA subjects of similar age and sex, patients diagnosed with GCA had a higher incidence (%) of amaurosis fugax (cumulative incidence ± SE: 2.1 ± 0.9 versus 0, respectively; p = 0.014) but similar rates of stroke, transient ischemic attack (TIA), and VTE. Among patients with GCA, neither baseline characteristics nor laboratory parameters at diagnosis reliably predicted risk of VTE or cerebrovascular events.

Conclusion

In this population-based study, the incidence of VTE, stroke and TIA was similar in patients with GCA compared to non-GCA subjects.

Correlation of clinical profile and specific histopathological features of temporal artery biopsies

BACKGROUND

This study sought to correlate the clinical features of patients with giant cell arteritis (GCA) who present with ophthalmic symptoms and signs, with 2 specific histopathological findings-the presence of giant cells and arterial wall neoangiogenesis. The goal was to assess if these pathological features might be useful in guiding the approach to patient management.

METHODS

Medical charts were retrospectively reviewed from 58 patients who underwent a temporal artery biopsy at a single institution. Detailed information was collected about the clinical presentation and course, with an emphasis on visual function. Histopathological and immunohistochemical techniques were used to examine temporal artery biopsies for evidence of inflammation. Correlations were made between the clinical data and the presence of giant cells and neoangiogenesis.

RESULTS

Twenty-one (34%) biopsies were positive for inflammation consistent with GCA. Although the percentage of positive biopsies with giant cells was high, neither the presence of giant cells nor neoangiogenesis was predictive of a patient's presenting visual symptoms, severity and bilaterality of vision loss, other ophthalmic manifestations of GCA, presence of headache or jaw claudication, or erythrocyte sedimentation rate. Giant cells were more common in patients with recent weight loss. Immunohistochemistry confirmed diagnoses but did not alter the clinical course or treatment plan.

CONCLUSIONS

There was no correlation between the clinical, specifically visual, features of GCA and the presence or absence of giant cells or neoangiogenesis in temporal artery biopsy specimens. Although the presence of neoangiogenesis may be important in the pathogenesis of GCA, our study showed no correlation between this finding and the clinical course.

Intravascular immunity as a key to systemic vasculitis: a work in progress, gaining momentum

Vascular inflammation contributes to the defence against invading microbes and to the repair of injured tissues. In most cases it resolves before becoming apparent. Vasculitis comprises heterogeneous clinical entities that are characterized by the persistence of vascular inflammation after it has served its homeostatic function. Most underlying mechanisms have so far remained elusive. Intravascular immunity refers to the surveillance of the vasculature by leucocytes that sense microbial or sterile threats to vessel integrity and initiate protective responses that entail most events that determine the clinical manifestations of vasculitis, such as end-organ ischaemia, neutrophil extracellular traps generation and thrombosis, leucocyte extravasation and degranulation. Understanding how the resolution of vascular inflammation goes awry in patients with systemic vasculitis will facilitate the identification of novel pharmacological targets and bring us a step closer in each patient to the selection of more effective and less toxic treatments.

Macrophages and angiogenesis in rheumatic diseases

Angiogenesis plays a key role in several rheumatic diseases, including rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, systemic sclerosis, systemic lupus erythematosus, and vasculitides. An imbalance between angiogenic inducers and inhibitors seems to be a critical factor in pathogenesis of these diseases. Macrophages promote angiogenesis during rheumatoid arthritis. In addition, macrophages can produce a variety of pro-angiogenic factors that have been associated with the angiogenic response occurring during other rheumatic diseases. Lastly, macrophages could be a target in the treatment of rheumatoid arthritis and other rheumatic diseases. Nevertheless, further studies are needed to better elucidate the exact role of macrophage in angiogenesis in these diseases.

Tocilizumab - a novel therapy for non-organ-specific autoimmune diseases

In the past decade, tocilizumab, an anti interleukin-6 agent, has been successfully developed as a therapeutic agent for the treatment of rheumatoid arthritis and systemic onset juvenile idiopathic arthritis. In addition to countering inflammation, tocilizumab is also known affect B cell as well as T cell function, thus modulating immune function, and impact osteoclasts, as well as vascular endothelial growth factor. As such, its efficacy is currently being explored in a large number of autoiommune conditions including a number of vasculitides, systemic lupus erythematosus, systemic sclerosis, polymyositis, graft versus host disease, relapsing polychondritis, as well as Behcet's syndrome, spondyloarthropathies, and tumor necrosis factor receptor associated periodic syndrome.

Emerging avenues linking inflammation, angiogenesis and Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune disease characterized by an inflammatory mononuclear infiltration and the destruction of epithelial cells of the lachrymal and salivary glands. The aetiology is unknown. The expression "autoimmune epithelitis" has been proposed as an alternative to SS, in view of the emerging central role of the epithelial cells in the disease pathogenesis. At the biomolecular level, the epithelial cells play an important role in triggering the autoimmune condition via antigen presentation, apoptosis, and chemokine and cytokines release. Inflammation and angiogenesis are frequently coupled in the pathological conditions associated to autoimmune diseases, and an angiogenic imbalance contributes to the pathogenesis of a number of inflammatory disorders. This work reviews the current knowledge of the molecular and cellular mechanisms underlying the pathogenesis of the inflammatory reactions that characterize SS. The literature and our data on the role of angiogenesis in the pathophysiology of the disease are discussed.

Acute effects of prostaglandin E1 and E2 on vascular reactivity and blood flow in situ in the chick chorioallantoic membrane

The chick chorioallantoic membrane (CAM) subserves gas exchange in the developing embryo and shell-less culture affords a unique opportunity for direct observations over time of individual blood vessels to pharmacologic interventions. We tested a number of lipids including prostaglandins PGE(1&2) for vascular effects and signaling in the CAM. Application of PGE(1&2) induced a decrease in the diameter of large blood vessels and a concentration-dependent, localized, reversible loss of blood flow through small vessels. The loss of flow was also mimicked by misoprostol, an agonist for 3 of 4 known PGE receptors, EP(2-4), and by U46619, a thromboxane mimetic. Selective receptor antagonists for EP(3) and thromboxane each partially blocked the response. This is a first report of the effects of prostaglandins on vasoreactivity in the CAM. Our model allows the unique ability to examine simultaneous responses of large and small vessels in real time and in vivo.

Immunotherapeutic implication of IL-6 blockade

IL-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6 contributes to host defense against acute environmental stress, continuous IL-6 production plays a significant pathological role in various autoimmune and chronic inflammatory diseases. To counter this drawback, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy of tocilizumab for patients with rheumatoid arthritis, Castleman's disease and systemic juvenile idiopathic arthritis, resulting in approval of this innovative biologic for their treatment. Moreover, a considerable number of case reports and pilot studies have indicated the beneficial effects of tocilizumab on other autoimmune and chronic inflammatory diseases. Further clinical studies to evaluate the efficacy and safety of tocilizumab for these diseases are essential.

A potent soluble epoxide hydrolase inhibitor, t-AUCB, acts through PPARγ to modulate the function of endothelial progenitor cells from patients with acute myocardial infarction

BACKGROUND

Epoxyeicosatrienoic acids (EETs) are natural angiogenic mediators regulated by soluble epoxide hydrolase (sEH). Inhibitors of sEH can stabilize EETs levels and were reported to reduce atherosclerosis and inhibit myocardial infarction in animal models. In this work, we investigated whether increasing EETs with the sEH inhibitor t-AUCB would increase angiogenesis related function in endothelial progenitor cells (EPCs) from patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

EPCs were isolated from 50 AMI patients and 50 healthy subjects (control). EPCs were treated with different concentrations of t-AUCB for 24h with or without peroxisome proliferator activated receptor γ (PPARγ) inhibitor GW9662. Migration of EPCs was assayed in trans-well chambers. Angiogenesis assays were performed using a Matrigel-Matrix in vitro model. The expression of vascular endothelial growth factor (VEGF), hypoxia-inducible factor 1α (HIF-1α) mRNA and protein in EPCs was measured by real-time PCR or Western blot, respectively. Also, the concentration of EETs in the culture supernatant was detected by ELISA. The activity of EPCs in the AMI patient group was reduced compared to healthy controls. Whereas increasing EET levels with t-AUCB promoted a dose dependent angiogenesis and migration in EPCs from AMI patients. Additionally, the t-AUCB dose dependently increased the expression of the angiogenic factors VEGF and HIF-α. Lastly, we provide evidence that these effects were PPARγ dependent.

CONCLUSION

The results demonstrate that the sEH inhibitor positively modulated the functions of EPCs in patients with AMI through the EETs-PPARγ pathway. The present study suggests the potential utility of sEHi in the therapy of ischemic heart disease.

Tocilizumab for the treatment of rheumatoid arthritis and other systemic autoimmune diseases: current perspectives and future directions

Interleukin (IL)-6 is a cytokine featuring redundancy and pleiotropic activity. While IL-6, when transiently produced, contributes to host defense against acute environmental stress, continuous dysregulated IL-6 production plays a significant pathological role in several systemic autoimmune diseases. In response to the expectation that IL-6 blockade would constitute a novel therapeutic strategy for the treatment of these diseases, tocilizumab, a humanized anti-IL-6 receptor antibody, was developed. Clinical trials have verified the efficacy and the safety of tocilizumab for patients with rheumatoid arthritis, resulting in approval of this innovative biologic for the treatment of rheumatoid arthritis in more than 90 countries worldwide. Pathological analyses of the effect of IL-6 on the development of autoimmune diseases and a considerable number of case reports and pilot studies have also indicated the beneficial effects of this antibody on other systemic autoimmune diseases, including systemic lupus erythematosus, systemic sclerosis, polymyositis, and large-vessel vasculitis.

Relapses and recurrences in giant cell arteritis: a population-based study of patients with biopsy-proven disease from northwestern Spain

We conducted the present study to determine the incidence of disease flares (relapses and recurrences) in a series of patients with biopsy-proven giant cell arteritis (GCA). We assessed a series of 174 patients who were diagnosed with biopsy-proven GCA, uniformly treated, and followed at the rheumatology division of Hospital Xeral-Calde (Lugo, Spain), the single rheumatology division for a well-defined population. All of them were followed for at least 1 year after the disease diagnosis. Seventy-one (40.8%) experienced relapses or recurrences of the disease. Patients who had relapses or recurrences did not show clinical differences when compared with the remaining biopsy-proven GCA patients. However, the total duration of corticosteroid therapy was significantly longer in those patients who had relapses or recurrences of the disease. The median dose of prednisone and the median duration of corticosteroid treatment at the time of the first relapse were 5 mg/d and 16 months, respectively. Headache (52%) was the most common feature at the time of the first relapse. Polymyalgia rheumatica manifestations occurred in 30% of the patients at that time. However, none of them developed visual loss. Thirty-two patients experienced recurrences of the disease when prednisone dose had been discontinued. The median time from the disease diagnosis to the time of the recurrence was 23 months. The presence of anemia (hemoglobin <12 g/dL) at the time of disease diagnosis was the best predictor of relapses or recurrences of GCA (odds ratio, 2.17; 95% confidence interval, 1.02-4.62; p = 0.04). The results from the present study confirm that relapses and recurrences are frequent in homogenously treated patients with biopsy-proven GCA. A chronic inflammatory response manifested by anemia at the time of disease diagnosis may predict the development of disease flares.

Anti-interleukin-6 receptor antibody, tocilizumab, for the treatment of autoimmune diseases

Interleukin (IL)-6 is a cytokine with multiple biological activities. It contributes to host defense against pathogens, whereas accelerated production of IL-6 plays a significant pathological role in various diseases. Clinical trials have demonstrated the efficacy of tocilizumab, a humanized anti-IL-6 receptor antibody, for patients with rheumatoid arthritis, Castleman's disease or juvenile idiopathic arthritis, leading to approval of this innovative drug for the treatment of these diseases. Since IL-6 has been demonstrated to play a significant role in the development of various other autoimmune and inflammatory diseases, tocilizumab can be expected to become a novel drug for such diseases as well.

Influence of CD40 rs1883832 polymorphism in susceptibility to and clinical manifestations of biopsy-proven giant cell arteritis

OBJECTIVE

To assess the potential association between CD40 rs1883832 polymorphism and biopsy-proven giant cell arteritis (GCA). We also studied the influence of the polymorphism on phenotypic expression of this vasculitis, in particular the development of visual ischemic manifestations.

METHODS

Three hundred five Spanish patients with biopsy-proven GCA and 788 matched controls were assessed. DNA from patients and controls was obtained from peripheral blood. Samples were genotyped for the CD40 rs1883832 C/T polymorphism using a predesigned TaqMan allele discrimination assay and by polymerase chain reaction amplification.

RESULTS

Patients with GCA showed a trend toward a higher frequency of the minor allele homozygote of rs1883832 (TT) compared to healthy controls (12.1% vs 8.3%, respectively; p = 0.05, OR 1.54, 95% CI 0.98-2.40). Also, a marginally significant increased frequency of the minor allele T was observed in patients with GCA who had visual ischemic manifestations (36.9%) compared to those without visual ischemic manifestations (27.7%; p = 0.04, OR 1.53, 95% CI 0.99-2.34). In this regard, patients with GCA carrying the minor allele T (either TT or TC) experienced visual ischemic manifestations more commonly than those carrying the CC genotype (58.5% vs 44.2%; p = 0.04, OR 1.78, 95% CI 0.99-3.22).

CONCLUSION

Our results suggest a potential implication of the CD40 rs1883832 C/T polymorphism in susceptibility to visual ischemic manifestations in individuals with biopsy-proven GCA.

Pathogenesis of giant cell arteritis: More than just an inflammatory condition?

Giant cell arteritis (GCA) is characterized by intimal hyperplasia and luminal obstruction leading to ischemic manifestations involving extra-cranial branches of carotid arteries and aorta. Histopathological lesions involve all layers of the arterial wall and are associated with multinucleated giant cells, fragmented internal elastic lamina and polymorphic cellular infiltrates, including T lymphocytes and macrophages. The pathophysiology of GCA is still poorly understood. After dendritic cell activation, CD4(+) T lymphocytes, T helper 1 (Th1) cells, produce interferon gamma and modulate macrophage activation and functions, and Th17 cells produce interleukin 17 (IL-17), which can induce cytokine production by macrophages and fibroblasts. Macrophages in the adventitia produce pro-inflammatory cytokines such as IL-1, IL-6 and tumor necrosis factor alpha. These cytokines promote arterial wall and systemic inflammation. Questions remain regarding the nature of the antigen(s) triggering dendritic cell activation and the mechanisms underlying vascular remodeling. Here we review recent advances in the pathogenesis of GCA, with emphasis on the interactions between cells of the immune system and components of the vessel wall, including vascular smooth muscle cells and endothelial cells, leading to vascular remodeling. Finally, we propose new areas of investigation that could help understand the triggering factors and key pathogenic events in GCA.

[Clinical and serological findings of giant-cell arteritis]

Giant cell arteritis (GCA) frequently appears as cranial arteritis (eg. temporal arteritis) with headache, pain on chewing and visual disturbances. In addition, extracranial manifestations are often observed leading to aneurysmatic dilatations and dissections of the aorta as well as stenoses of large thoracic, abdominal or limb arteries. The vascular signs are accompanied by general disease symptoms, e.g. malaise, elevated temperatures, weight loss and depression. Polymyalgia rheumatica (PMR) is the most frequent rheumatic manifestation of GCA but also occurs independently from GCA. The structural correlate for the PMR symptoms is first and foremost extra-articular inflammation (tenosynovitis, bursitis) of large joints and the vertebral column (interspinal bursitis). In addition, vasculitis of large arteries in PMR must be considered particularly in the presence of high inflammatory activity. While specific laboratory markers for GCA and PMR are lacking elevated values for the erythrocyte sedimentation rate and C-reactive protein are present in almost all patients at disease onset. Besides the clinical evaluation, the serological acute phase reaction represents the main parameter for the course during therapy of this relatively frequent disease in elderly people.

The spectrum of vascular involvement in giant-cell arteritis: clinical consequences of detrimental vascular remodelling at different sites

Although repeatedly reported in the literature, the extracranial involvement by giant-cell arteritis has been considered anecdotal until recent years. The emergence of new or improved imaging techniques along with a closer follow-up of these patients and their increase in life expectancy are beginning to underline that the clinical impact of extracranial involvement by GCA may be more relevant than previously thought. This review focuses on the extent of vascular involvement in GCA as reported by pathology and imaging studies as well as the clinical consequences of imperfect vascular remodelling in various vascular territories.

The soluble VEGF receptor sFlt1 contributes to endothelial dysfunction in CKD

Endothelial dysfunction contributes to the increased cardiovascular risk that accompanies CKD. We hypothesized that the soluble VEGF receptor 1 (sFlt-1), a VEGF antagonist, plays a role in endothelial dysfunction and decreased angiogenesis in CKD. We enrolled 130 patients with CKD stages 3 to 5 and 56 age- and gender-matched control patients. Plasma sFlt-1 levels were higher in patients with CKD and, after multivariate regression analyses, exclusively associated with renal function and levels of vWF, a marker of endothelial dysfunction. Compared with serum from control patients, both recombinant sFlt-1 and serum from patients with CKD had antiangiogenic activity in the chick chorioallantoic membrane (CAM) assay, induced endothelial cell apoptosis in vitro, and decreased nitric oxide generation in two different endothelial cell lines. Pretreating the sera with an antibody against sFlt-1 abrogated all of these effects. Furthermore, we observed increased sFlt1 levels in 5/6-nephrectomized rats compared with sham-operated animals. Finally, using real-time PCR and ELISA, we identified monocytes as a possible source of increased sFlt-1 in patients with CKD. Our findings show that excess sFlt-1 associates with endothelial dysfunction in CKD and suggest that increased sFlt-1 may predict cardiovascular risk in CKD.

Strokes at time of disease diagnosis in a series of 287 patients with biopsy-proven giant cell arteritis

Patients with giant cell arteritis (GCA) generally present with cranial ischemic manifestations that are directly related to vascular involvement. They may also experience strokes in the territory of the carotid or the vertebrobasilar artery. We conducted the current study to assess the frequency and predictors of strokes in general, and of vertebrobasilar stroke in particular, at the time of diagnosis in a series of 287 consecutive patients with biopsy-proven GCA diagnosed over a 27-year period at the single hospital for a well-defined population of northwestern Spain.During the study period, 8 (2.8%) patients had strokes (1 in the carotid and 7 in the vertebrobasilar territory) between the onset of symptoms of the disease and 4 weeks after the onset of corticosteroid therapy. Six of the 7 patients with vertebrobasilar stroke were men. In most cases the vertebrobasilar stroke occurred after the onset of corticosteroid therapy. Smoking history was more common among patients with vertebrobasilar stroke (p = 0.01). Patients with vertebrobasilar stroke more commonly had permanent visual loss due to arteritic involvement of ophthalmic branches derived from the internal carotid (3/7; 42.9%) than the rest of GCA patients (33/280; 11.8%) (p = 0.05). Patients with strokes had higher hemoglobin values (13.2 +/- 1.5 g/dL) than patients without (11.7 +/- 1.6 g/dL) (p = 0.009). Moreover, only 1 (14.3%) of the 7 patients with vertebrobasilar stroke had anemia compared to 157 (56.1%) of the remaining 280 patients (p = 0.05). The best predictors of stroke were permanent visual loss (odds ratio [OR], 5.42) and arterial hypertension (OR, 5.06). In contrast, women (OR, 0.10) and patients with anemia at the time of disease diagnosis (OR, 0.11) had a significantly reduced risk of suffering strokes. Smoking history was the best positive predictor of vertebrobasilar stroke (OR, 5.22). In contrast, a reduced risk of suffering vertebrobasilar strokes was found in individuals who had anemia at the time of GCA diagnosis (OR, 0.13).Results of the current study show an increased risk of strokes, in the vertebrobasilar territory in particular, at the time of GCA diagnosis. Patients with biopsy-proven GCA and traditional cardiovascular risk factors or permanent visual loss have an increased risk of suffering strokes. Results also suggest a potential protective role of anemia against the development of these cerebrovascular complications.