Large-vessel Giant Cell Arteritis Research Articles

A Case of Large Vessel Giant Cell Arteritis Presenting With Cough and Diagnosed Using an FDG-PET Scan

A Case of Large Vessel Giant Cell Arteritis Presenting With Cough and Diagnosed Using an FDG-PET Scan

Prognostic value of 18 FDG-PET at diagnosis and follow-up in giant cell arteritis: An observational restrospective study

ObjectivesTo evaluate the ability of 18FDG PET/CT, at diagnosis of giant cell arteritis (GCA) and during follow-up, to predict occurrence of relapse in large-vessel GCA (LV-GCA). MethodsWe conducted a retrospective study using the French Study Group for Large-Vessel Vasculitis (GEFA) network. Data from patients with LV-GCA diagnosed by PET/CT and who had PET/CT in the following year were collected. For each PET/CT, PET vascular activity score (PETVAS) and total vascular score (TVS) were assessed, and their ability to predict the occurrence of subsequent relapse was assessed. ResultsA total of 65 LV-GCA patients were included, of whom 55 had undergone a follow-up PET/CT 3 to 12 months after the diagnosis of GCA. Patients for whom the second PET/CT (PET2) was performed during active GCA were excluded. PETVAS and TVS decreased between PET1 and PET2 in all patients (p < 0.001). There was no correlation between vascular activity scores in PET2 and time to prednisone taper. For relapse prediction, at PET1, the AUC of the TVS and PETVAS were respectively 51.9 and 41.9 at 6 months, 55.3 and 49.7 at 1 year, 55 and 55.7 at 2 years. For PET2, the AUC were respectively 46.1 and 46.7 at 6 months, 52.1 and 48.9 at 1 year, 58.4 and 52.3 at 2 years. ConclusionPET vascular activity scores at diagnosis and at follow-up PET/CT performed outside a period of GCA activity do not display high performance to predict the occurrence of subsequent relapse in LV-GCA patients.

Imaging to predict early relapses after treatment discontinuation in patients with large vessel giant cell arteritis – A cohort study

ObjectivesTo investigate the value of [18F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in predicting relapse after treatment discontinuation in patients with large-vessel giant cell arteritis (LV-GCA). MethodsThis study included patients with LV-GCA whose treatment was discontinued between 2018 and 2023. All patients underwent PET/CT and/or MRI at the time of treatment discontinuation in clinical remission. Qualitative and quantitative PET/CT scores, by measuring standardized uptake values (SUV), and semiquantitative MRI scores of the aorta and supraaortic vessels were compared between patients who relapsed within 4 months after treatment discontinuation and those who did not. ResultsForty patients were included (median age 67.4 years, interquartile range (IQR) 60.8–74.0; 77.5 % females). Eleven patients (27.5 %) relapsed after treatment discontinuation (time to relapse 1.9 months, IQR 1.4–3.3). Patients who relapsed were comparable to those who remained in remission with respect to the presence of active vasculitis on MRI and/or PET/CT (54.5% vs. 58.6 %, p = 1.0), the number of segments with vasculitic findings on MRI (0, IQR 0.0–1.5, vs. 2, IQR 0.0–3.0, p = 0.221) or the highest SUV artery/liver ratio on PET/CT (1.5, IQR 1.4–1.6, vs. 1.3, IQR 1.2–1.6, p = 0.505). The median number of vasculitic segments on PET/CT was 2.5 (IQR 0.5–4.5) in those with vs. 0 (IQR 0.0–1.5, p = 0.085) in those without relapse, and the PET/CT scores 4.5 (IQR 0.75–8.25) vs. 0 (IQR 0.0–3.0, p = 0.172). ConclusionPET/CT or MRI at treatment stop did not predict relapse and may not be suited to guide treatment decisions in patients with LV-GCA in remission.

Characterising polymyalgia rheumatica on whole-body 18F-FDG PET/CT: an atlas.

The impact of modern imaging in uncovering the underlying pathology of PMR cannot be understated. Long dismissed as an inflammatory syndrome with links to the large vessel vasculitis giant cell arteritis (GCA), a pathognomonic pattern of musculotendinous inflammation is now attributed to PMR and may be used to confirm its diagnosis. Among the available modalities, 18F-fluorodeoxyglucose (18F-FDG) PET/CT is increasingly recognized for its high sensitivity and specificity, as well as added ability to detect concomitant large vessel GCA and exclude other relevant differentials like infection and malignancy. This atlas provides a contemporary depiction of PMR's pathology and outlines how this knowledge translates into a pattern of findings on whole body 18F-FDG PET/CT that can reliably confirm its diagnosis.

Magnetic Resonance Imaging Findings Corresponding to Vasculitis as Defined via [18F]FDG Positron Emission Tomography or Ultrasound

Background: We sought to investigate magnetic resonance imaging (MRI) parameters that correspond to vasculitis observed via [18F]FDG positron emission tomography/computed tomography (PET/CT) and ultrasound in patients with large-vessel giant cell arteritis (LV-GCA). Methods: We performed a cross-sectional analysis of patients diagnosed with LV-GCA. Patients were selected if MRI, PET/CT, and vascular ultrasound were performed at the time of LV-GCA diagnosis. Imaging findings in vessel segments (axillary segment per side, thoracic aorta) assessed using at least two methods were compared. Vessel wall thickening, oedema, and contrast agent enhancement were each assessed via MRI. Results: Twelve patients with newly diagnosed LV-GCA were included (seven females, 58%; median age 72.1, IQR 65.5–74.2 years). The MRI results showed mural thickening in 9/24 axillary artery segments. All but 1 segment showed concomitant oedema, and additional contrast enhancement was found in 3/9 segments. In total, 8 of these 9 segments corresponded to vasculitic findings in the respective segments as observed via PET/CT, and 2/9 corresponded to vasculitis in the respective ultrasound images. If MRI was performed more than 6 days after starting prednisone treatment, thickening and oedema were seen in only 1/24 segments, which was also pathologic according to ultrasound findings but not those obtained via PET/CT. Four patients had mural thickening, oedema, and contrast enhancement in the aorta, among whom three patients also had vasculitic findings observed via PET/CT. Isolated mural thickening in one patient corresponded to a negative PET/CT result. Conclusions: In the MRI results, mural thickening due to oedema corresponded to vasculitic PET/CT findings but not vasculitic ultrasound findings. The duration of steroid treatment may reduce the sensitivity of MRI.

Vasculitis distribution and clinical characteristics in giant cell arteritis: a retrospective study using the new 2022 ACR/EULAR classification criteria.

Giant cell arteritis (GCA) is the most common vasculitis of the elderly. In recent years, advanced imaging has to a certain extent replaced temporal artery biopsy (TAB) to aid diagnosis in many institutions and helped to identify three major phenotypes of GCA, namely, cranial GCA (c-GCA), large-vessel non-cranial GCA (LV-GCA), and a combination of these two patterns called mixed-GCA, which all show different clinical patterns. Recent 2022 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria respect the changing conception and clinical practice during the last two decades. In this cohort study, we present vasculitis distribution and baseline characteristics using the 2022 ACR/EULAR classification criteria as well as the EULAR core data set. In this retrospective study from Southern Norway, we identified all patients diagnosed with GCA between 2006 and 2019 in our single-center fast-track clinic (FTC). We included all patients who were examined using ultrasound (US) of cranial as well as non-cranial large vessels at diagnosis to depict vascular distribution. EULAR core data set, ACR 1990, and 2022 ACR/EULAR classification criteria were used to characterize the cohort. Seventy-seven patients were diagnosed with GCA at our institution in the aforementioned period. Seventy-one patients (92.2%) were diagnosed with the help of US and included in the further analysis. The 2022 ACR/EULAR classification criteria allocated 69 patients (97.2%), while the ACR 1990 classification criteria allocated 49 patients (69.0%) in our cohort as having GCA. Mixed-GCA was the most common type in 33 patients (46.5%). Weight loss was significantly more common in patients with large-vessel non-cranial vasculitis in LV-GCA and mixed-GCA. Headache, on the other hand, was significantly more common in patients with involvement of cranial vessels. Mixed GCA was the most common form of GCA in our cohort. In our study, the 2022 ACR/EULAR classification criteria seem to be a more useful tool compared with the old ACR 1990 classification criteria to allocate GCA patients diagnosed and treated at our US-based FTC as having GCA.

Lights and shadows on the efficacy of tocilizumab monotherapy in large vessel giant cell arteritis.

Lights and shadows on the efficacy of tocilizumab monotherapy in large vessel giant cell arteritis.

Clinical phenotype and complications of large vessel giant cell arteritis: A systematic review and meta-analysis.

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. 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. 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 -4.53years), had longer delay to diagnosis (mean difference 3.03months) 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. 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.

Response to: 'Biases in Large Vessel Vasculitis' by Mukhtyar.

We thank Mukhtyar for his interest in our report showing the differences of giant cell arteritis (GCA) based on the presence of large vessel involvement (LVI) [1] and for providing some meaningful comments to deepen the discussion [2]. First, Mukhtyar wonders the accuracy of the term of large vessel GCA (LV-GCA). Certainly, it is anatomically correct to use the term ‘cranial or extracranial GCA’ because the Chapel Hill Consensus defines the arteries outside an organ as large vessels, including the superficial temporal artery and the ophthalmic artery distributed in the cranial region [3]. However, ‘LV-GCA’ is also a commonly used term to refer to GCA involving the aorta and/or its branches [4, 5]. Currently, it is still chaotic about the terminology, and the unification is awaited. Second, distinction between GCA and Takayasu arteritis (TAK) is an important and challenging problem. In our cohort, we don’t have any patients that meet the 1990 American College of Rheumatology (ACR) classification for TAK [6], nor the 2022 ACR/EULAR classification criteria for TAK [7]. However, the differentiation of GCA and TAK can be problematic, especially in patients around the age threshold with stenoses of the aortic branches. The 2022 ACR/EULAR classification for TAK and GCA [7, 8] focused on clinical information such as the distribution of affected arteries, and this will help us differentiate GCA and TAK. Also, some recent studies focus on GCA or TAK using genetic or molecular approaches [9]. That kind of research from the perspective of basic medicine can contribute to distinguishing GCA and TAK, and further research is anticipated.

Ultrasound halo count in the differential diagnosis of atherosclerosis and large vessel giant cell arteritis

ObjectiveTo determine the diagnostic discriminant validity between large vessel giant cell arteritis (LV-GCA) and atherosclerosis using ultrasound (US) intima-media thickness (IMT) measurements.MethodsWe included 44 patients with LV-GCA and 42 with high-risk atherosclerosis. US examinations of the axillary, subclavian, and common carotid arteries (CCA) were systematically performed using a MylabX8 system (Genoa, Italy) with a 4–15-MHz probe. IMT ≥ 1 mm was accepted as pathological.ResultsThe LV-GCA cohort included 24 females and 20 males with a mean age of 72.8 ± 7.6 years. The atherosclerosis group included 25 males and 17 females with a mean age of 70.8 ± 6.5 years. The mean IMT values of all arteries included were significantly higher in LV-GCA than in atherosclerosis. Among LV-GCA patients, IMT ≥ 1 mm was seen in 31 axillary, 30 subclavian, and 28 CCA. In the atherosclerotic cohort, 17 (38.6%) had IMT ≥ 1 mm with axillary involvement in 2 patients, subclavian in 3 patients, carotid distal in 14 patients (5 bilateral), and isolated carotid proximal affectation in 1 case. A cutoff point greater than 1 pathological vessel in the summative count of axillary and subclavian arteries or at least 3 vessels in the count of six vessels, including CCA, showed a precision upper 95% for GCA diagnosis.ConclusionThe IMT is higher in LV-GCA than in atherosclerosis. The proposed US halo count achieves an accuracy of > 95% for the differential diagnosis between LV-GCA and atherosclerosis. The axillary and subclavian arteries have higher discriminatory power, while carotid involvement is less specific in the differential diagnosis.

Takayasu arteritis and large-vessel giant cell arteritis in Italian population. Comprehensive analysis from a single institutional cohort of 184 cases

ObjectiveTo compare clinical and imaging characteristics in patients with Takayasu arteritis (TAK) and large vessel-giant cell arteritis (LV-GCA) in an Italian population. MethodsWe conducted a retrospective monocenter study comparing characteristics and outcomes of a cohort of 59 patients with TAK and a cohort of 127 patients with LV-GCA diagnosed between 1996 and 2016. Most of them (92%) were followed up for at least 24 months at Reggio Emilia Hospital (Italy). We also reviewed the literature discussing the results of the published manuscripts comparing LV-GCA to TAK ResultsLV-GCA patients had a higher prevalence of males (p = 0.003), and more frequently presented with cranial symptoms (p = 0.001), fever ≥38 °C (p = 0.007), polymyalgia rheumatica (p = 0.001), and hypertension (p = 0.001), and they had higher ESR levels at diagnosis (p = 0.0001). Differently, TAK patients had longer delay to diagnosis from the beginning of symptoms (p = 0.048), they presented more frequently with loss of pulses of large arteries (p = 0.0001), vascular bruits (p = 0.001), limb claudication (p = 0.003), myocardial infarction/angina (p = 0.03), and hypertension induced by renal artery stenosis (p = 0.001). Regarding treatment, TAK patients received a higher total and at 1 year cumulative prednisone doses (p = 0.0001 and p = 0.001, respectively), they had a longer duration of prednisone therapy (p = 0.008), and received during follow-up more frequently traditional immunosuppressants (p = 0.0001) and biological agents (p = 0.0001). Flares were more frequently observed in TAK patient (p = 0.001), while no differences were observed for long-term remission. New vascular procedures during the follow-up were more frequently performed in TAK patients (p = 0.0001). Regarding imaging at diagnosis, TAK patients had more frequently vascular stenosis/occlusion (p = 0.0001) and a higher number of vessels with structural damage per person (p = 0.0001), while LV-GCA patients had a higher number of inflamed vessels per person (p = 0.0001).Comparing the involved vascular districts at diagnosis for the presence of vessel inflammation and/or arterial damage, patients with LV-GCA had a more frequent involvement of thoracic and abdominal aorta (p = 0.024 and p = 0.007, respectively), and axillary, iliac and femoral arteries (p = 0.018, p = 0.002, and p = 0.0001. respectively), while in TAK patients, brachiocephalic, celiac, mesenteric and renal arteries were more frequently involved (p = 0.011, p = 0.019, p = 0.019, and p = 0.005, respectively). At imaging arterial damage at diagnosis was more frequently observed in TAK patients, specifically at common carotid, brachiocephalic, and subclavian arteries (p = 0.0001, p = 0.006, p = 0.0001, respectively) and descending aorta (p = 0.022). Regarding imaging during the follow-up, TAK patients developed more frequently new vascular stenosis/occlusion (p = 0.0001) and new vascular thickening (p = 0.002), no differences were observed for the development of new dilatation/aneurysm between the two vasculitides. ConclusionPatients with TAK and LV-GCA show a number of similarities and also differences. Indeed, it is unclear whether they are part of the same disease spectrum or they are different conditions. As more information regarding the pathogenesis and etiology becomes known, answers to these questions are like to be forthcoming.

Ultrasonography in the assessment of disease activity in cranial and large-vessel giant cell arteritis: a prospective follow-up study.

We evaluated sensitivity to change and discriminative abilities of vascular US scores in disease monitoring in the follow-up of a prospective cohort of new-onset cranial and large-vessel (LV) GCA patients. Baseline and follow-up (8 weeks, 24 weeks and 15 months) US of temporal arteries (TA), carotid and axillary arteries (LV) included assessment of halo and measurement of the intima media complex (IMC). Max IMC, max halo IMC, sum IMC, sum halo IMC, mean IMC, halo count and the Southend halo score were calculated. The provisional OMERACT US score, OGUS, was obtained, taking the average of temporal arteries and axillary arteries IMCs divided by their normal cut-off values. Baseline US was positive in 44/47 patients (72% TA, 72% LV). Sensitivity to change of all composite US scores containing TAs was evident by week 8 onward. LVs responded poorly and new axillary US lesions emerged in six patients despite clinical remission. The OGUS showed a large magnitude of change and is considered the score least prone to potential bias. All TA-based US scores showed moderate-strong correlation with disease activity markers. OGUS, TA halo count, Southend TA halo score, TA sum IMC and TA mean IMC showed potential to discriminate remission and relapse with area under the curve ≥0.8. The OGUS is suggested as an outcome measurement for the assessment of treatment response in clinical trials. The abilities of US scores to discriminate remission and relapse are encouraging and should be further explored.

Predictive Factors of Giant Cell Arteritis in Polymyalgia Rheumatica Patients.

Polymyalgia rheumatica (PMR) is an inflammatory rheumatism of the shoulder and pelvic girdles. In 16 to 21% of cases, PMR is associated with giant cell arteritis (GCA) that can lead to severe vascular complications. Ruling out GCA in patients with PMR is currently a critical challenge for clinicians. Two GCA phenotypes can be distinguished: cranial GCA (C-GCA) and large vessel GCA (LV-GCA). C-GCA is usually suspected when cranial manifestations (temporal headaches, jaw claudication, scalp tenderness, or visual disturbances) occur. Isolated LV-GCA is more difficult to diagnose, due to the lack of specificity of clinical features which can be limited to constitutional symptoms and/or unexplained fever. Furthermore, many studies have demonstrated the existence-in varying proportions-of subclinical GCA in patients with apparently isolated PMR features. In PMR patients, the occurrence of clinical features of C-GCA (new onset temporal headaches, jaw claudication, or abnormality of temporal arteries) are highly predictive of C-GCA. Additionally, glucocorticoids' resistance occurring during follow-up of PMR patients, the occurrence of constitutional symptoms, or acute phase reactants elevation are suggestive of associated GCA. Research into the predictive biomarkers of GCA in PMR patients is critical for selecting PMR patients for whom imaging and/or temporal artery biopsy is necessary. To date, Angiopoietin-2 and MMP-3 are powerful for predicting GCA in PMR patients, but these results need to be confirmed in further cohorts. In this review, we discuss the diagnostic challenges of subclinical GCA in PMR patients and will review the predictive factors of GCA in PMR patients.

Intima-media thickness cut-off values depicting "halo sign" and potential confounder analysis for the best diagnosis of large vessel giant cell arteritis by ultrasonography.

Vascular ultrasound enables fast-track diagnosis of giant cell arteritis (GCA), but this method remains subjective. We aimed to determine intima-media thickness (IMT) cut-off values for large vessel GCA (LV-GCA) and identify the clinically relevant factors influencing it. We included 214 patients referred for ultrasound evaluation within a fast-track clinic due to suspected GCA. IMT was measured in axillary, brachial, subclavian, superficial femoral, and common carotid arteries (CCA), in a place without identifiable atherosclerotic plaques. IMT cut-off values for vasculitis were determined by comparing measurements in arteries classified as vasculitis vs. controls without GCA/polymyalgia rheumatica (PMR). Giant cell arteritis was diagnosed in 81 individuals, including extracranial LV-GCA in 43 individuals. Isolated PMR was diagnosed in 50 subjects. In 83 remaining patients, another diagnosis was confirmed, and they served as controls. The rounded optimal IMT cut-off values for the diagnosis of axillary vasculitis were 0.8 mm, subclavian-0.7 mm, superficial femoral-0.9 mm, CCA-0.7 mm, and brachial-0.5 mm. The IMT cut-off values providing 100% specificity for vasculitis (although with reduced sensitivity) were obtained with axillary IMT 1.06 mm, subclavian-1.35 mm, superficial femoral-1.55 mm, CCA-1.27 mm, and brachial-0.96 mm. Axillary and subclavian arteritis provided the best AUC for the diagnosis of GCA, while carotid and axillary were most commonly involved (24 and 23 patients, respectively). The presence of calcified atherosclerotic plaques was related to an increase of IMT in both patients and controls, while male sex, age ≥ 68, hypertension, and smoking increased IMT in controls but not in patients with GCA. Cut-off values for LV-GCA performed best in axillary and subclavian arteritis but expanding examination to the other arteries may add to the sensitivity of GCA diagnosis (another location, e.g., brachial arteritis) and its specificity (identification of calcified atherosclerotic plaques in other arteries such as CCA, which may suggest applying higher IMT cut-off values). We proposed a more linear approach to cut-off values with two values: one for the most accurate and the other for a highly specific diagnosis and also considering some cardiovascular risk factors.

Giant cell arteritis: A population-based retrospective cohort study exploring incidence and clinical presentation in Canterbury, Aotearoa New Zealand.

To determine the epidemiology and clinical features of giant cell arteritis (GCA) in Canterbury, Aotearoa New Zealand, with a particular focus on extra-cranial large vessel disease. Patients with GCA were identified from radiology and pathology reports, outpatient letters and inpatient hospital admissions in the Canterbury New Zealand from 1 June 2011 to 31 May 2016. Data was collected retrospectively based on review of electronic medical records. There were 142 cases of GCA identified. 65.5% of cases were female with a mean age of 74.2 years. The estimated population incidence for biopsy-proven GCA was 10.5 per 100,000 people over the age of 50 and incidence peaked between 80 and 84 years of age. 10/142 (7%) people were diagnosed with large vessel GCA, often presenting with non-specific symptoms and evidence of vascular insufficiency including limb claudication, vascular bruits, blood pressure and pulse discrepancy, or cerebrovascular accident. Those with limited cranial GCA were more likely to present with the cardinal clinical features of headache and jaw claudication. Patients across the two groups were treated similarly, but those with large vessel disease had greater long-term steroid burden. Rates of aortic complication were low across both groups, although available follow-up data was limited. This study is the first of its kind to describe the clinical characteristics of large vessel GCA in a New Zealand cohort. Despite small case numbers, two distinct subsets of disease were recognized, differentiating patients with cranial and large vessel disease. Our results suggest that utilization of an alternative diagnostic and therapeutic approach may be needed to manage patients with large vessel disease.

Association between the patterns of large-vessel lesions and treatment outcomes in patients with large-vessel giant cell arteritis

We aimed to identify associations between patterns of large-vessel lesions of large-vessel giant cell arteritis (LV-GCA) and treatment outcomes. We extracted data on 68 newly-diagnosed patients with LV-GCA from a retrospective, multi-centric, nationwide registry of GCA patients treated with glucocorticoids between 2007 and 2014. Patients with aortic lesions were identified based on findings from contrast-enhanced computed tomography (CT), magnetic resonance imaging, or positron emission tomography-CT (group 2, n=49). Patients without aortic lesions were subdivided into LV-GCA with or without subclavian lesions defined as group 1 (n=9) or group 3 (n=10), respectively. Primary outcome evaluation was failure to achieve clinical remission by week 24 and/or relapse within 104 weeks. The mean age and proportion of patients with cranial lesions and polymyalgia rheumatica in group 2 was numerically lower than in the other two groups. Large-vessel lesions in group 3 included carotid, pulmonary, renal, hepatic or mesenteric lesions. The cumulative rate of poor treatment outcomes over two years was 11.1%, 55.3%, and 88.0% in groups 1, 2, and 3, respectively (by Kaplan-Meier analysis). The mean time to poor outcome was significantly different between the groups. Classification by subclavian and aortic lesions may be useful to determine treatment strategy.

Cranial and extracranial large-vessel giant cell arteritis share a genetic pattern of interferon-gamma pathway.

Two main different clinical phenotypes of giant cell arteritis (GCA) have been described, the classic cranial pattern and the extracranial large-vessel (LV) pattern. Since interferon gamma (IFNG) has shown to be a pivotal cytokine in the pathophysiology of GCA, our aim was to evaluate for the first time the influence of IFNG and IFNG receptor 1 (IFNGR1) polymorphisms in the different clinical phenotypes of GCA. Two IFNG polymorphisms (rs2069718 G/A and rs1861493 A/G) and one polymorphism in IFNGR1 (rs1327474 G/A) were genotyped in 191 patients with biopsy-proven cranial GCA, 109 with extracranial LV-GCA and 490 healthy controls. A comparative study was conducted between patients with cranial and extracranial LV-GCA. No significant differences in genotype, allele, and haplotype frequencies of IFNG polymorphisms were found between GCA patients with the classic cranial pattern and the extracranial LV-GCA pattern. Similar results were found for genotype and allele frequencies of IFNGR1 polymorphism. It was also the case when patients with extracranial LV-GCA were compared with healthy controls. Our results show that IFNG and IFNGR1 polymorphisms do not influence the clinical phenotype of expression of GCA. Classic cranial GCA and extracranial LV-GCA seem to share a genetic pattern of IFNG pathway.

Incidence of giant cell arteritis in six districts of Paris, France (2015–2017)

This prospective population-based study estimated the incidence of giant cell arteritis (GCA) in northeastern Paris. GCA cases diagnosed between 2015 and 2017 were obtained from local hospital and community-based physicians and the national health insurance system database. Criteria for inclusion were living in the study area at that time and fulfilling the 1990 American College of Rheumatology classification criteria and/or its expanded version. Cranial and large-vessel GCA cases were defined by the presence or absence of cranial signs and/or symptoms, respectively. Annual incidence was calculated by dividing the number of incident cases by the size of the study population ≥ 50years old. Completeness of case ascertainment was assessed by a three-source capture-recapture analysis. Among the 62 included cases, 42 (68%) were women, mean (± SD) age 77.3 ± 9.1years. The annual incidence ofGCA in northeastern Parisand completeness of case ascertainment were estimated at 7.6 (95% CI 5.9-9.8) per 100,000 inhabitants ≥ 50years old and 66% (95% CI 52-92%), respectively. Incidence increased with age, peaked at age 80-89years, and was almost twice as high in women versus men. Large-vessel GCA cases, mean (± SD) age 68.6 ± 11.5years, accounted for 8% of all GCA cases.In this study,GCA epidemiology was mainly driven by cases with cranial GCA signs or symptoms and incidence results were consistentwith recent European and past French studies.

Case Report: Giant Cell Arteritis presenting with 6th Nerve Palsy without Ischemic Optic Neuropathy

Purpose: Giant cell arteritis (GCA) can be a difficult condition to identify in the early stages especially in the absence of the pathognomonic arteritic anterior ischemic optic neuropathy. Optometrists serve an important role in correctly triaging and initiating appropriate work-up and treatment for this emergent condition. This case report and review serves as a refresher of the systemic and ocular signs and symptoms of GCA. Background: GCA is a systemic autoimmune condition characterized by granulomatous inflammation of medium and large arteries in patients over 50. The most well-known constellation of signs and symptoms include new onset headache, jaw claudication, scalp tenderness, temporal artery abnormality with painless vision loss secondary to arteritic anterior ischemic optic neuropathy. However, it is important to be aware of alternate presenting signs and symptoms including pain anywhere in the distribution of the external carotid (occipital, neck, tongue, throat, ear) and signs of large vessel GCA (arm/limb claudication, chest/back pain, Raynaud’s phenomenon) and Polymyalgia Rheumatica (PMR) (bilateral hip/shoulder pain and morning stiffness). Case Report: An 86-year-old Caucasian female presents for a referred exam regarding new onset diplopia with concurrent occipital headache, neck pain and sore throat originally dismissed as symptoms of her other systemic health conditions. ESR, CRP and platelets were elevated on serology and subsequent temporal artery biopsy was positive for GCA. Oral steroids were initiated, and she was lost to follow up after her ocular symptoms resolved. Conclusion: GCA can present with a large range of manifestations, and many are nonspecific and easily attributable to other causes especially when it deviates from the classic constellation of new onset headache, jaw claudication, scalp tenderness and temporal artery abnormality with painless vision loss. Optometrists as primary eye care providers may be the first point of contact and need to be cognizant of the broader set of manifestations to minimize delays in diagnosis and treatment of this life and vision threatening condition. CE Notification: This article is available as a COPE accredited CE course. You may take this course for 1-hour credit. Read the article and take the qualifying test to earn your credit. Click here to Enroll (https://www.crojournal.com/case-report-giant-cell-arteritis-presenting-with-6th-nerve-palsy-without-ischemic-optic-neuropathy) Please check COPE course expiry date prior to enrollment. The COPE course test must be taken before the course expiry date.

P295 Establishing adenosine deaminase 2 activity in a cohort of patients with large vessel vasculitis

Abstract Background/Aims Deficiency of adenosine deaminase 2 (DADA2) leads to a broad phenotype; some patients develope vasculitis and strokes, and others have predominantly haematological manifestations. Small, medium and large vessel vasculitis has been described. In contrast, plasma ADA2 activity is elevated in inflammatory conditions including systemic lupus erythematosus and systemic juvenile idiopathic arthritis with macrophage activation syndrome. The role of ADA2 and how its deficiency associates with the vasculitides is not well understood. Using a well-characterised large vessel vasculitis cohort, we sought to establish the potential role of ADA2 activity. Methods ADA2 activity was measured in adults with Takayasu arteritis (TA), large vessel giant cell arteritis (LV-GCA), intracranial vasculitis (IV) and healthy control (HC) subjects using a coupled spectrophotometric assay. Plasma from 11 patients with genotyped DADA2 and 10 patients heterozygous for pathogenic variants in ADA2 were used to define thresholds for deficiency and carrier status respectively (DADA2 activity 0 - 0.90 U/L, ADA2 carrier activity 2.02 - 10.62 U/L). Activity levels above the upper limit of normal (ULN) were defined as &amp;gt; 99th percentile of the HC activity (30.3U/L). To assess potential associations with TA disease status, ADA2 was measured prospectively in matched active and remission samples. TA disease activity was determined as active, grumbling or stable using clinical and radiological features, physician impression, CRP, ESR and Indian Takayasu clinical Activity Score (ITAS). Results No patients had deficient ADA2 activity while 7 subjects had activity within the carrier range (1 HC [1.9%], 5 TA [3.7%], 1 LV-GCA [2.3%]). Compared to HC levels (17.43 [14.11 - 20.78] U/L), activity in the TA group was significantly increased (TA 19.68U/L, p = 0.0061), while LV-GCA and IV were not significantly different. In 20 cases, activity exceeded the ULN; 16 TA (11.9%, p = 0.044; 4 active, 2 grumbling, 10 stable) and 4 LV-GCA (9.1%, ns). In TA, there was a positive correlation between ADA2 activity and ESR (Spearman R = 0.2863, p = 0.0009) but not with CRP or ITAS score. Subgroup analysis revealed ADA2 activity was most prominently elevated in the stable group relative to HCs (TA stable 20.54 U/L [8.08 - 48.66], median +17.8%, p = 0.0006), but not with active or grumbling disease. Consistent with this, prospective analysis demonstrated a significant increase in ADA2 activity in remission vs active disease (p = 0.024), with activity increasing in 18 (62%) patients achieving remission. Conclusion There were no cases of ADA2 deficiency in this cohort. Consistent with other inflammatory conditions, ADA2 activity was elevated in TA compared to HC subjects. Surprisingly, increased ADA2 activity was linked to stable TA in both cross-sectional and prospective analyses. This may suggest a potential role of ADA2 enzyme activity in vascular repair and regrowth - possibly tying in with known elevated levels of ADA2 activity in growing children. Disclosure A. Porter: None. R. Maughan: None. C. Pericleous: None. A. Kiprianos: None. H. Jee: None. P. Lee: None. T. Youngstein: None. J. Mason: None.