Diagnosis Of Giant Cell Arteritis Research Articles

Temporal arteritis presenting as third nerve palsy - a case report and review of literature.

Giant Cell Arteritis (GCA), also known as Temporal Arteritis, is a type of large vessel vasculitis primarily affecting the elderly population. It typically manifests with headaches, visual impairment, and jaw claudication. Although third nerve palsy as the primary presentation of GCA is rare, it has been reported in previous instances. In this report, we describe the case of a patient presenting with pupil-sparing third nerve palsy, ultimately diagnosed with GCA, and successfully managed with steroids and tocilizumab. A lady in her 80s with past medical history of well-controlled hypertension, bladder cancer in remission, a twenty-pack year smoking history, cervical and lumbar spine stenosis, and recent immunizations presented with acute onset of right-sided pupil-sparing third nerve palsy. Labs were pertinent for an elevated ESR and CRP. Brain imaging was without acute abnormalities. A temporal artery biopsy established evidence of healed arteritis and a diagnosis of GCA was made. The patient was treated with pulse-dose steroids followed by an oral steroid taper and tocilizumab. At one month follow-up, there was partial resolution in her ophthalmoplegia. We underscore the importance of considering temporal arteritis as a potential cause of third nerve palsy in the elderly before attributing it solely to microvascular ischemia, particularly in patients with constitutional features. Additionally, in our comprehensive literature review, we aim to consolidate the existing data from similar presentations, shedding light on the clinical manifestation and disease trajectory.

Cranial and extracranial manifestations of giant cell arteritis: a single-center observational study.

Giant cell arteritis (GCA) presents two major phenotypes - cranial (cGCA) and extracranial (exGCA). exGCA may be overlooked. The study aimed to compare the clinical characteristics between cGCA and exGCA. Electronic medical records of patients treated between January 2015 and July 2023 at the Department of Rheumatology were searched for the diagnosis of GCA. The clinical characteristics of patients with cGCA, exGCA, and overlapping GCA manifestations were compared. Out of 32 patients with GCA, 20 had cGCA, 7 had exGCA, and 5 had overlap manifestations. The groups did not differ significantly in demographics, clinical signs/symptoms, or laboratory test results. Importantly, the combined group of patients with exGCA and overlap GCA had a statistically significant delay in initiating treatment (median 12 weeks) compared to patients with cGCA (median 4 weeks; p = 0.008). Our study confirmed the insidious nature of exGCA, which lacks distinctive clinical symptoms and consequently leads to delayed treatment.

Diagnostic Strategy Using Color Doppler Ultrasound of Temporal Arteries in Patients With High Clinical Suspicion of Giant Cell Arteritis : A Prospective Cohort Study.

Giant cell arteritis (GCA) is the most prevalent systemic vasculitis in people older than 50 years. Any delay in diagnosis impairs patients' quality of life and can lead to permanent damage, particularly vision loss. To evaluate a diagnostic strategy for GCA using color Doppler ultrasound of the temporal artery as a first-line diagnostic test, temporal artery biopsy (TAB) as a secondary test, and physician expertise as the reference method. Prospective multicenter study with a 2-year follow-up. (ClinicalTrials.gov: NCT02703922). Patients were referred by their general practitioner or ophthalmologist to a physician with extensive experience in GCA diagnosis and management in one of the participating centers: 4 general and 2 university hospitals. 165 patients with high clinical suspicion of GCA, aged 79 years (IQR, 73 to 85 years). The diagnostic procedure was ultrasound, performed less than 7 days after initiation of corticosteroid therapy. Only ultrasound-negative patients underwent TAB. Bilateral temporal halo signs seen on ultrasound were considered positive. Ultrasound and TAB results were compared with physician-diagnosed GCA based on clinical findings and other imaging. Diagnosis of GCA was confirmed in 44%, 17%, and 21% of patients by ultrasound, TAB, and clinical expertise and/or other imaging tests, respectively. Their diagnosis remained unchanged at 1 month, and 2 years for those with available follow-up data. An alternative diagnosis was made in 18% of patients. The proportion of ultrasound-positive patients among patients with a clinical GCA diagnosis was 54% (95% CI, 45% to 62%). Small sample size, no blinding of ultrasound and TAB results, lack of an objective gold-standard comparator, and single diagnostic strategy. By using ultrasound of the temporal arteries as a first-line diagnostic tool in patients with high clinical suspicion of GCA, further diagnostic tests for patients with positive ultrasound were avoided. Tender "Recherche CH-CHU Poitou-Charentes 2014."

Risk loci involved in giant cell arteritis susceptibility: a genome-wide association study.

Giant cell arteritis is an age-related vasculitis that mainly affects the aorta and its branches in individuals aged 50 years and older. Current options for diagnosis and treatment are scarce, highlighting the need to better understand its underlying pathogenesis. Genome-wide association studies (GWAS) have emerged as a powerful tool for unravelling the pathogenic mechanisms involved in complex diseases. We aimed to characterise the genetic basis of giant cell arteritis by performing the largest GWAS of this vasculitis to date and to assess the functional consequences and clinical implications of identified risk loci. We collected and meta-analysed genomic data from patients with giant cell arteritis and healthy controls of European ancestry from ten cohorts across Europe and North America. Eligible patients required confirmation of giant cell arteritis diagnosis by positive temporal artery biopsy, positive temporal artery doppler ultrasonography, or imaging techniques confirming large-vessel vasculitis. We assessed the functional consequences of loci associated with giant cell arteritis using cell enrichment analysis, fine-mapping, and causal gene prioritisation. We also performed a drug repurposing analysis and developed a polygenic risk score to explore the clinical implications of our findings. We included a total of 3498 patients with giant cell arteritis and 15 550 controls. We identified three novel loci associated with risk of giant cell arteritis. Two loci, MFGE8 (rs8029053; p=4·96 × 10-8; OR 1·19 [95% CI 1·12-1·26]) and VTN (rs704; p=2·75 × 10-9; OR 0·84 [0·79-0·89]), were related to angiogenesis pathways and the third locus, CCDC25 (rs11782624; p=1·28 × 10-8; OR 1·18 [1·12-1·25]), was related to neutrophil extracellular traps (NETs). We also found an association between this vasculitis and HLA region and PLG. Variants associated with giant cell arteritis seemed to fulfil a specific regulatory role in crucial immune cell types. Furthermore, we identified several drugs that could represent promising candidates for treatment of this disease. The polygenic risk score model was able to identify individuals at increased risk of developing giant cell arteritis (90th percentile OR 2·87 [95% CI 2·15-3·82]; p=1·73 × 10-13). We have found several additional loci associated with giant cell arteritis, highlighting the crucial role of angiogenesis in disease susceptibility. Our study represents a step forward in the translation of genomic findings to clinical practice in giant cell arteritis, proposing new treatments and a method to measure genetic predisposition to this vasculitis. Institute of Health Carlos III, Spanish Ministry of Science and Innovation, UK Medical Research Council, and National Institute for Health and Care Research.

Parietal branch of the superficial temporal artery: An underutilized biopsy site

Purpose: Giant cell arteritis (GCA) is an immune-mediated vasculitis that can lead to significant symptoms and disease sequelae such as headaches, fevers, weight loss, jaw pain, optic neuropathy with permanent vision loss, and stroke. The gold standard for diagnosis of GCA is a temporal artery biopsy (TAB) as it has a high specificity and sensitivity. The TAB is commonly harvested from the frontal branch of the superficial temporal artery, however given its location, there are potentially significant consequences including facial nerve injury and poor cosmetic outcomes. An alternative to this method is biopsy of the parietal branch, as it reduces the risk of facial nerve injury and comfortably hides the scar line within the hair of most patients. Results: We describe in detail our department's TAB technique and experience from pre-procedure preparation to post-procedure care. Conclusion: The parietal branch TAB is a typically underutilised, well tolerated and viable alternative to the frontal branch TAB and it may be considered in the first instance to reduce the risk of complications.

P032 Designing a workshop for a temporal artery biopsy simulation

Abstract Background/Aims A temporal artery biopsy (TAB) is performed to confirm a diagnosis of giant cell arteritis (GCA) and it is recommended by clinical practice guidelines. Historically there have been limited opportunities to perform this procedure and teaching has been largely informal and non standardised. This impacts a trainee’s confidence and competence and potentially patient safety. Simulation is crucial in modern day surgical education and so we designed, organised and delivered a wetlab to teach the steps of TAB to address these issues. Methods The event took place at the Welsh Institute for Minimal Access Therapy (WIMAT) centre in Cardiff. The WIMAT team developed the TAB models to be used. The event covered all of the theoretical aspects of performing a TAB, a demonstration on how to map the temporal artery, how to perform an ultrasound doppler procedure to locate the temporal artery and finally hands on experience performing a TAB with two different complexity models. Participants were asked to complete a 30 item Google Forms Questionnaire to help us to evaluate pre and post session knowledge, understanding and learning experiences pertaining to TAB. Results Participants noted significant improvements in their knowledge and understanding pertaining to all domains covered. A lack of knowledge, a lack of procedures previously performed, concern about damaging the facial nerve and lack of senior support/supervision were all identified as reasons as to why trainees get apprehensive when it comes to performing a TAB. Conclusion This novel formal teaching event provides a blueprint for deaneries to use in their teaching of TAB’s which can benefit trainees and patients. Modern surgical education benefits from wetlabs with expert supervision. Our findings also emphasise the benefits of cross specialty collaborative work. Disclosure S. Rehan: None. P. Watts: None. I. Williams: None. P. Hennessy: None. C. O’Flaherty: None. A. Haridas: None.

P190 Protocolised ultrasonography led pathway has a high sensitivity for diagnosis of primary large vessel vasculitis

Abstract Background/Aims Ultrasonography (US) for diagnosis of large vessel vasculitis (LVV) is a recommended first line diagnostic procedure. Our county has an annual incidence of 57.5/million for primary LVV (giant cell arteritis (GCA) 48.3/million; Takayasu 2.5/million; unclassified LVV 6.4/million). Our protocolised fast-track US pathway has reduced visual loss from 18.7% to 11.5%. We present the results of our first 1000 unique referrals. Methods Unique requests for US from January 2017 were analysed. Protocolised US examination of the arteries includes superficial temporal artery (STA) and its rami, followed by the entire axillary artery, followed by other arteries as necessary. Halo sign in at least two different arteries was needed for diagnosis of LVV. A temporal artery biopsy (TAB) or positron emission tomography (PET) were requested if the US was negative AND CRP was ≥20mg/L (or missing) AND an alternate explanation for the raised CRP was not immediately apparent. For those where a second test was not requested OR if it was negative, prednisolone was tapered rapidly, and a patient-initiated follow-up allowed rapid re-assessment. If referring physician or patient did not want a second test, GCA was diagnosed on clinical grounds alone and the pathway was considered to have failed. Results Median age was 73 (IQR 13); 11/1000 referrals were for people <50 years of age. The median delay for the procedure was 4 (IQR 4) days. Prednisolone had been started a median of 4 (IQR 5) days previously. 279/1000 (28%) US scans demonstrated vasculitis. Pre-steroid CRP was ≥20mg/L in 283 cases and unavailable in 7. An alternate explanation for the raised CRP was found in 102 cases, 181 were referred for a second test, and 7 received a clinical diagnosis of GCA without a second test. The second test was diagnostic in 31/181 (17%) - 24/139 (17%) TAB, 7/42 (17%) PET. 3/150 cases with a negative second test and 4/431 cases with CRP <20mg/L were diagnosed with GCA on patient-initiated follow-up. The delayed diagnosis did not result in visual loss. 202/279 (72%) US positive cases had bilateral STA involvement. The addition of axillary artery imaging picked up a further 53 (19%) cases; 24/279 (9%) cases needed imaging of other arteries. The sensitivity and negative predictive value of the pathway are 96% (310/324) and 98% (683/690) respectively. Conclusion Our protocolised US led pathway for diagnosis of LVV is highly sensitive and allows disease exclusion with high certainty. Routine US of the superficial temporal artery and its rami, and the entire axillary artery provide diagnosis in 91% of cases but ability to scan more arteries improves yield in a further 9% of cases. Composite testing with US plus second test, stratified by CRP levels, can be recommended as a gold standard diagnostic tool for LVV. Disclosure C.B. Mukhtyar: None. G. Ducker: None. C. Beadsmoore: None. K. Sisson: None. C. Jones: None.

Limb arteries involvement assessed by FDG/PET CT at diagnosis of giant cell arteritis and risk of relapse: An observational study

IntroductionSteroids and anti-IL6 biotherapy are highly effective in obtaining remission in patients with giant cell arteritis (GCA) but the risk of relapses remains high. We aimed to identify predictors of relapse in GCA. MethodsAll consecutive patients admitted with a new diagnosis of GCA – according to the 2022 American College of Rheumatology/EULAR (ACR/EULAR) classification criteria – between May 2011 and May 2022 were eligible for this study. The primary outcome was the GCA relapse rate over the 36-months follow up. Factors associated with the primary outcome and time to first relapse were analyzed. ResultsOne hundred and eight patients (74 [69–81] years, 64.8% women) with a new diagnosis of GCA were studied. GCA was biopsy-proven in 65 (60.2%) cases. Ninety-eight (90.7%) FDG/PET CT scans performed at diagnosis were available for review. All patients received steroids given for 21.0 [18.0–28.5] months, associated with methotrexate (n=1, 0.9%) or tocilizumab (n=2, 1.9%). During a median follow-up of 27.5 [11.4–35.0] months, relapse occurred in 40 (37%) patients. Multivariable Cox regression model, including general signs, gender, aortic wall thickness, FDG uptake in arterial wall and IV steroid pulse as covariates, showed that both general signs (HR 2.0 [1.0–4.0, P<0.05) and FDG uptake in limb arteries (HR 2.7 [1.3–5.5], P<0.01) at diagnosis were associated with GCA relapse. ConclusionFDG uptake in limb arteries at diagnosis is a predictor of relapse in newly diagnosed GCA.

Ultrasound intima-media thickness cut-off values for the diagnosis of giant cell arteritis using a dual clinical and MRI reference standard and cardiovascular risk stratification.

To derive segmental cut-off values and measures of diagnostic accuracy for the intima-media thickness of compressed temporal artery segments for the diagnosis of giant cell arteritis (GCA) on the patient level. To examine the influence of cardiovascular risk. Retrospectively, patients evaluated for GCA with an ultrasound of the temporal arteries and an MRI of the head, including a T1-fatsat-black blood (T1-BB) sequence, were identified and classified based on cardiovascular risk and a dual reference standard of T1-BB on the segmental level and the clinical diagnosis on the patient level. Intima-media thickness of the common superficial temporal artery (CSTA), frontal and parietal branches (FB, PB) were measured by compression technique. Statistically and clinically optimal (specificity of approx. 90% for the patient level) cut-offs were derived. Diagnostic accuracy was evaluated on the patient level. The population consisted of 144 patients, 74 (51.4%) with and 70 (48.6%) without GCA. The statistically optimal cut-offs were 0.86 mm, 0.68 mm and 0.67 mm for the CSTA, the FB and PB, respectively. On the patient level sensitivity and specificity were 86.5 and 81.4%. Clinically optimal cut-offs were 1.01 mm, 0.82 mm and 0.69 mm and showed a sensitivity of 79.7% and a specificity of 90.0%. For patients without high cardiovascular risk, statistically optimal cut-offs showed a sensitivity of 89.6% and a specificity of 90.5%. Newly derived ultrasound intima-media thickness cut-offs with a dual reference standard show high diagnostic accuracy on the patient level for the diagnosis of GCA, particularly in patients without high cardiovascular risk.

Recurrent Vision Loss in a Patient with Giant Cell Arteritis while on High Dose Corticosteroids

Giant cell arteritis (GCA) is a chronic vasculitis that can lead to permanent vision loss. In this case we describe a patient with permanent monocular vision loss from GCA, managed with long-term glucocorticoids, who presented with elevated erythrocyte sedimentation rate and acute visual loss. This patient was promptly given intravenous steroids, with initial improvement, however, she again experienced acute vision loss on the fourth day of treatment. Given the rare nature of this recurrent GCA-related vision loss during treatment, a broader workup was pursued without an alternative cause identified. Temporal biopsy was not performed due to concern of a false-negative in the setting of chronic steroid use. In this report we discuss the long-term monitoring and management of GCA, recurrence in the acute treatment setting, and present evidence related to diagnosis of GCA in the context of long-term steroid use.

Phase Specific Health Care Costs Associated with Giant Cell Arteritis in Ontario, Canada.

To estimate the additional health care system costs associated with giant cell arteritis (GCA) in the year pre-diagnosis, post diagnosis, and over long-term follow up compared to individuals with similar demographics and comorbidities without GCA. We performed a population-based study using health administrative data. Newly diagnosed cases of GCA (between 2002 and 2017 and ages 66 years and older) were identified using a validated algorithm and matched 1:6 to comparators using propensity scores. Follow up data was accrued until death, outmigration, or March 31, 2020. The costs associated with care were determined across three phases: the year before the diagnosis of GCA, the year after, and ongoing costs thereafter. The cohort consisted of 6,730 cases of GCA and 40,380 matched non-GCA comparators. The average age was 77 years (interquartile range 72-82) and 68.2% were female. A diagnosis of GCA was associated with an increased cost of $6,619.4 (95% CI 5,964.9 - 7274.0) per patient during the 1-year pre-diagnostic period; $12,150.3 (95% CI 11,233.1 - 13,067.6) per patient in the 1-year post-diagnostic phase, and $20,886.2 (95% CI 17,195.2 - 24,577.2) per patient during ongoing care for year 3 onwards. Increased costs were driven by inpatient hospitalizations, physician services, hospital outpatient clinic services, and emergency department visits. A diagnosis of GCA was associated with increased health care costs during all three phases of care. Given the substantial economic burden, strategies to reduce the healthcare utilization and costs associated with GCA are warranted.

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.

Myocardial infarction in a population-based cohort of patients with biopsy-confirmed giant cell arteritis in southern Sweden

ObjectivesTo determine the incidence rate (IR) of myocardial infarction (MI), relative risk of MI, and impact of incident MI on mortality in individuals with biopsy-confirmed giant cell arteritis (GCA).MethodsMIs in...

Performance of a fast-track pathway for giant cell arteritis in Waikato, Aotearoa New Zealand.

Giant cell arteritis (GCA) is the most common primary vasculitis in adults over 50 years of age. To facilitate early diagnosis and reduce harms from corticosteroids and temporal artery biopsies, fast-track pathways have been established. We review the benefits of the fast-track pathway set up in Waikato, Aotearoa New Zealand. Patients were collected prospectively as part of the fast-track pathway from 2014 to 2022. Their records were then reviewed retrospectively to collect data on clinical features, investigations and treatment. There were 648 individual patients over the study period who had a colour Doppler ultrasound (CDUS) of the temporal arteries. There were 17 true positive CDUS, giving a sensitivity of 10.3% (95% confidence interval [CI] 6.3-15.5%) and specificity of 99.8% (95% CI 99.1-100%). Patients with GCA and a positive scan had significantly fewer steroids than those with GCA and a negative scan (p=0.0037). There were 376 patients discharged after a CDUS who did not have a diagnosis of GCA, resulting in reduced corticosteroid and temporal artery biopsy exposure. This is a real-life study that reflects the benefits of fast-track pathways in Aotearoa New Zealand to patients and healthcare systems. It also shows the effect of corticosteroids on positive CDUS, an important consideration when setting up an fast-track pathway.

Sudden Visual Loss due to Arteritic Anterior Ischaemic Optic Neuropathy: A Rare Manifestation of Eosinophilic Granulomatosis with Polyangiitis.

eosinophilic granulomatosis with polyangiitis (EGPA) is a rare multisystem inflammatory disease characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of various organs. While the eye is uncommonly affected in patients with EGPA, multiple ophthalmic manifestations have been reported, which can result in serious visual impairment without timely treatment. we report the case of a 79-year-old woman with a history of asthma and nasal polyps who presented with low-grade fever, mild alteration of mental status, and fatigue. Chest X-ray revealed bilateral interstitial infiltrates. Lab tests showed elevated C-reactive protein level and eosinophilia (eosinophil count, 4.6 x109 cells/l); blood cultures and parasitological examination of stools tested negative. Four days after presentation, the patient reported sudden and severe blurring of vision in her left eye. Ophthalmological examination revealed bilateral swollen optic disc and visual field loss, more severe in the left eye. A diagnosis of EGPA complicated by arteritic anterior ischaemic optic neuropathy (A-AION) was proposed, while an alternative or concurrent diagnosis of giant cell arteritis was ruled out based on clinical picture. Immunosuppressive treatment with high-dose intravenous glucocorticoids was promptly started. The patient's visual defect did not improve; however, two months later, no worsening was registered on ophthalmic reassessment. A-AION is an infrequent but severe manifestation of EGPA, requiring prompt diagnosis and emergency-level glucocorticoid therapy to prevent any further vision loss. Disease awareness and a multidisciplinary approach are crucial to expedite diagnostic work-up and effective management of EGPA-related ocular complications. Arteritic ischaemic optical neuropathy is a potential cause of sudden and severe visual loss in eosinophilic granulomatosis with polyangiitis (EGPA) patients.Visual loss due to arteritic ischaemic optical neuropathy is rarely reversible; however, a timely glucocorticoid treatment may prevent further progression of visual impairment.Multidisciplinary approach is crucial to expedite diagnostic work-up and effective management of EGPA patients with ocular complications.

Visualization of the Internal Thoracic Arteries in Giant Cell Arteritis on 18 F-FDG Semiconductor PET/CT.

A 72-year-old woman presented with the fever and the pain of skull and face for 2 weeks. 18 F-FDG PET/CT equipped with semiconductor detectors revealed strong uptake not only in the temporal, cervical, subclavian arteries, and aorta, but also in the bilateral internal thoracic arteries. The diagnosis of giant cell arteritis was made. Semiconductor PET can visualize small arteries such as the internal thoracic artery. The patients with giant cell arteritis are at a high risk of ischemic heart disease, and inflammatory involvement of the internal thoracic arteries may affect the outcome of coronary artery bypass grafting.

DWI scrolling artery sign for the diagnosis of giant cell arteritis: a pattern recognition approach

ObjectivesTo investigate the diagnostic accuracy of a pattern recognition approach for the evaluation of MRI scans of the head with diffusion-weighted imaging (DWI) in suspected giant cell arteritis (GCA).MethodsRetrospectively, 156...

Development of a diagnostic prediction model for giant cell arteritis by sequential application of Southend Giant Cell Arteritis Probability Score and ultrasonography: a prospective multicentre study

Giant cell arteritis is a critically ischaemic disease with protean manifestations that require urgent diagnosis and treatment. European Alliance of Associations for Rheumatology (EULAR) recommendations advocate ultrasonography as the first investigation for suspected giant cell arteritis. We developed a prediction tool that sequentially combines clinical assessment, as determined by the Southend Giant Cell Arteritis Probability Score (SGCAPS), with results of quantitative ultrasonography. This prospective, multicentre, inception cohort study included consecutive patients with suspected new onset giant cell arteritis referred to fast-track clinics (seven centres in Italy, the Netherlands, Spain, and UK). Final clinical diagnosis was established at 6 months. SGCAPS and quantitative ultrasonography of temporal and axillary arteries with three scores (ie, halo count, halo score, and OMERACT GCA Score [OGUS]) were performed at diagnosis. We developed prediction models for diagnosis of giant cell arteritis by multivariable logistic regression analysis with SGCAPS and each of the three ultrasonographic scores as predicting variables. We obtained intraclass correlation coefficient for inter-rater and intra-rater reliability in a separate patient-based reliability exercise with five patients and five observers. Between Oct 1, 2019, and June 30, 2022, we recruited and followed up 229 patients (150 [66%] women and 79 [34%] men; mean age 71 years [SD 10]), of whom 84 were diagnosed with giant cell arteritis and 145 with giant cell arteritis mimics (controls) at 6 months. SGCAPS and all three ultrasonographic scores discriminated well between patients with and without giant cell arteritis. A reliability exercise showed that the inter-rater and intra-rater reliability was high for all three ultrasonographic scores. The prediction model combining SGCAPS with the halo count, which was termed HAS-GCA score, was the most accurate model, with an optimism-adjusted C statistic of 0·969 (95% CI 0·952 to 0·990). The HAS-GCA score could classify 169 (74%) of 229 patients into either the low or high probability groups, with misclassification observed in two (2%) of 105 patients in the low probability group and two (3%) of 64 of patients in the high probability group. A nomogram for easy application of the score in daily practice was created. A prediction tool for giant cell arteritis (the HAS-GCA score), combining SGCAPS and the halo count, reliably confirms and excludes giant cell arteritis from giant cell arteritis mimics in fast-track clinics. These findings require confirmation in an independent, multicentre study. Royal College of Physicians of Ireland, FOREUM.

The one-year infection risk among patients diagnosed with giant cell arteritis: use of antibiotics and hospitalisations

Abstract Objectives Patients with giant cell arteritis (GCA) primarily have their infections managed by primary care providers and hospitalisation is rarely necessary. Existing studies in GCA focus on infection-related hospitalisations only, whereas the use of antibiotic prescriptions is largely unknown. This study aims to examine the one-year overall infection risk among patients with GCA. Methods This nationwide observational cohort study included patients aged ≥50 years with a first-time GCA diagnosis in the Danish National Patient Registry (1996–2022). Patients with GCA were matched 1:10 by sex and date of birth with general population individuals and followed from date of diagnosis. Overall infections were defined as redeemed antibiotic prescriptions or infection-related hospitalisations. Utilising a pseudo-observation approach, we assessed 1-year cumulative incidence proportions (CIP), risk differences (RD), and relative risks (RR) of infections. Results The study included 17 773 incident patients with GCA and 177 730 reference individuals. Patients with GCA had a 1-year CIP of 52.4% (95% CI: 51.7–53.2) for overall infections and 17.6% (95% CI: 17.1–18.2) for infection-related hospitalisations. Compared with the reference cohort, patients with GCA had a RR of 1.40 (95% CI: 1.38–1.42) for overall infections and 2.71 (95% CI: 2.61–2.82) for infection-related hospitalisations. Additionally, higher cumulative glucocorticoid doses, advanced age (≥70 years), and higher comorbidity were associated with an increased risk of infections among patients with GCA. Conclusions The use of antibiotic prescriptions and infection-related hospitalisations in the first year after a GCA diagnosis is high compared with the background population. The cumulative glucocorticoid dose is associated with the infection risk.

Halo sign on temporal artery ultrasound versus temporal artery biopsy for giant cell arteritis.

Giant cell arteritis (GCA) is a systemic, inflammatory vasculitis primarily affecting people over the age of 50 years. GCA is treated as a medical emergency due to the potential for sudden, irreversible visual loss. Temporal artery biopsy (TAB) is one of the five criteria of the American College of Rheumatology (ACR) 1990 classification, which is used to aid the diagnosis of GCA. TAB is an invasive test, and it can be slow to obtain a result due to delays in performing the procedure and the time taken for histopathologic assessment. Temporal artery ultrasonography (US) has been demonstrated to show findings in people with GCA such as the halo sign (a hypoechoic circumferential wall thickening due to oedema), stenosis or occlusion that can help to confirm a diagnosis more swiftly and less invasively, but requiring more subjective interpretation. This review will help to determine the role of these investigations in clinical practice. To evaluate the sensitivity and specificity of the halo sign on temporal artery US, using the ACR 1990 classification as a reference standard, to investigate whether US could be used as triage for TAB. To compare the accuracy of US with TAB in the subset of paired studies that have obtained both tests on the same patients, to investigate whether it could replace TAB as one of the criteria in the ACR 1990 classification. We used standard Cochrane search methods for diagnostic accuracy. The date of the search was 13 September 2022. We included all participants with clinically suspected GCA who were investigated for the presence of the halo sign on temporal artery US, using the ACR 1990 criteria as a reference standard. We included studies with participants with a prior diagnosis of polymyalgia rheumatica. We excluded studies if participants had had two or more weeks of steroid treatment prior to the investigations. We also included any comparative test accuracy studies of the halo sign on temporal artery US versus TAB, with use of the 1990 ACR diagnostic criteria as a reference standard. Although we have chosen to use this classification for the purpose of the meta-analysis, we accept that it incorporates unavoidable incorporation bias, as TAB is itself one of the five criteria. This increases the specificity of TAB, making it difficult to compare with US. We excluded case-control studies, as they overestimate accuracy, as well as case series in which all participants had a prior diagnosis of GCA, as they can only address sensitivity and not specificity. Two review authors independently assessed the studies for inclusion in the review. They extracted data using a standardised data collection form and employed the QUADAS-2 tool to assess methodological quality. As not enough studies reported data at our prespecified halo threshold of 0.3 mm, we fitted hierarchical summary receiver operating characteristic (ROC) models to estimate US sensitivity and also to compare US with TAB. We graded the certainty of the evidence using the GRADE approach. Temporal artery ultrasound was investigated in 15 studies (617 participants with GCA out of 1479, 41.7%), with sample sizes ranging from 20 to 381 participants (median 69). There was wide variation in sensitivity with a median value of 0.78 (interquartile range (IQR) 0.45 to 0.83; range 0.03 to 1.00), while specificity was fair to good in most studies with a median value of 0.91 (IQR 0.78 to 1.00; range 0.40 to 1.00) and four studies with a specificity of 1.00. The hierarchical summary receiver operating characteristic (HSROC) estimate of sensitivity (95% confidence interval (CI)) at the high specificity of 0.95 was 0.51 (0.21 to 0.81), and 0.84 (0.58 to 0.95) at 0.80 specificity. We considered the evidence on sensitivity and specificity as of very low certainty due to risk of bias (-1), imprecision (-1), and inconsistency (-1). Only four studies reported data at a halo cut-off > 0.3 mm, finding the following sensitivities and specificities (95% CI): 0.80 (0.56 to 0.94) and 0.94 (0.81 to 0.99) in 55 participants; 0.10 (0.00 to 0.45) and 1.00 (0.84 to 1.00) in 31 participants; 0.73 (0.54 to 0.88) and 1.00 (0.93 to 1.00) in 82 participants; 0.83 (0.63 to 0.95) and 0.72 (0.64 to 0.79) in 182 participants. Data on a direct comparison of temporal artery US with biopsy were obtained from 11 studies (808 participants; 460 with GCA, 56.9%). The sensitivity of US ranged between 0.03 and 1.00 with a median of 0.75, while that of TAB ranged between 0.33 and 0.92 with a median of 0.73. The specificity was 1.00 in four studies for US and in seven for TAB. At high specificity (0.95), the sensitivity of US and TAB were 0.50 (95% CI 0.24 to 0.76) versus 0.80 (95% CI 0.57 to 0.93), respectively, and at low specificity (0.80) they were 0.73 (95% CI 0.49 to 0.88) versus 0.92 (95% CI 0.69 to 0.98). We considered the comparative evidence on the sensitivity of US versus TAB to be of very low certainty because specificity was overestimated for TAB since it is one of the criteria used in the reference standard (-1), together with downgrade due to risk of bias (-1), imprecision (-1), and inconsistency (-1) for both sensitivity and specificity. There is limited published evidence on the accuracy of temporal artery US for detecting GCA. Ultrasound seems to be moderately sensitive when the specificity is good, but data were heterogeneous across studies and either did not use the same halo thickness threshold or did not report it. We can draw no conclusions from accuracy studies on whether US can replace TAB for diagnosing GCA given the very low certainty of the evidence. Future research could consider using the 2016 revision of the ACR criteria as a reference standard, which will limit incorporation bias of TAB into the reference standard.