Performance of the 2022 ACR/EULAR giant cell arteritis classification criteria for diagnosis in patients with suspected giant cell arteritis in routine clinical care

The impact of histopathological criteria for definite vasculitis in giant cell arteritis: retrospective analysis of temporal artery biopsies

Histopathological findings associated with definite vasculitis in temporal artery biopsy (TAB) defined in 2022 ACR/EULAR classification criteria for Giant Cell Arteritis (GCA) was published in 2022. We aimed to evaluate the TAB of our GCA patients for histopathological findings associated with definite vasculitis. Patients who were diagnosed with GCA by clinicians and underwent TAB between January 2012 and May 2022 were included. Hospital electronic records and patients' files were reviewed retrospectively. A total of 90 patients' pathology reports were evaluated by a pathologist and a rheumatologist. In cases where microscopic findings were not specified in the pathology reports, histopathologic specimens were re-evaluated (n = 36). A standard checklist was used for histopathological findings of definite vasculitis. Patients were divided into two groups; (i) definite vasculitis-GCA and (ii) non-definite-GCA group, and the clinical and demographic characteristics for all patients were compared. The mean age of patients was 69.8 (± 8.5) years and 52.2% were female. In the first evaluation, 66 (73.3%) patients had a diagnosis of vasculitis according to pathology reports. In the re-evaluation of biopsy specimens, at least one definite finding of vasculitis was observed in TAB of 10/24 (41.6%) patients whose microscopic findings were not specified in the pathology reports. The ROC analysis showed that biopsy length had diagnostic value in predicting the diagnosis of definite vasculitis (AUC: 0.778, 95% CI: 0.65-0.89, p < 0.001). In those with a biopsy length of ≥ 1 cm, sensitivity was 76.5%, specificity was 64.3%, and PPV value was 92. In multivariate analysis, the most significant factor associated with definite vasculitis was biopsy length (OR: 1.18 (1.06-1.31), p = 0.002). Microscopic findings were reported in over 70% of patients. Reinterpretation of results according to a standard check-list improved the impact of TAB in the diagnosis of GCA. A biopsy length ≥ 1 cm was found to contribute towards a definitive histopathological vasculitis diagnosis.

[Utility of applying a diagnostic algorithm in giant cell arteritis based on the level of clinical suspicion]

INTRODUCTION

To reach the diagnosis of giant cell arteritis (GCA), signs, symptoms, laboratory tests, imaging findings, and occasionally anatomopathological results from temporal artery biopsy are evaluated. This study describes the results of an algorithm analysis based on clinical and ultrasound evaluation of patients with suspected GCA, highlighting its diagnostic utility by contrasting its use in different clinical suspicion scenarios.

METHOD

Prospective multicenter study evaluating patients referred with suspected GCA through a preferential circuit (fast track), grouping them according to low or high clinical suspicion of GCA. Each of these scenarios is evaluated by biopsy and ultrasound for all patients, resulting in positive, indeterminate, or negative outcomes, yielding six possible groups. Potential areas of improvement are explored, emphasizing that, following a negative or indeterminate ultrasound, 18-FDG-PET-CT could be recommended. We analyze the results and application of a diagnostic algorithm, confirming its efficiency and applicability based on whether there is high or low clinical suspicion.

RESULTS

Sixty-nine patients (41 in the high suspicion group and 28 in the low suspicion group). There were 41 new diagnoses of GCA: 35 in the high suspicion group and 6 in the low suspicion group. Using ultrasound alone, the initial algorithm has an overall diagnostic efficiency of 72.5%, which improves to 80.5% when including 18F-FDG-PET/CT. The negative predictive value of ultrasound in patients with low clinical suspicion is 84.6%, and the positive predictive value of ultrasound in patients with high suspicion is 100%, improving sensitivity from 57.1% to 80.8% with 18F-FDG-PET/CT in this scenario. Temporal artery biopsy was performed on all patients, with no differences in sensitivity or specificity compared to ultrasound. In cases where all three tests - ultrasound, biopsy, and 18F-FDG-PET/CT - are performed, sensitivity increases to 92.3% in patients with high clinical suspicion.

CONCLUSION

In situations of high clinical suspicion, the algorithm provides sufficient information for the diagnosis of GCA if ultrasound is positive. A negative ultrasound is sufficient to rule out the diagnosis in the context of low clinical suspicion. 18-FDG-PET-CT may be useful in patients with high suspicion and negative or indeterminate ultrasound results.

Diagnosing vasculitis with ultrasound: findings and pitfalls

Rheumatologists are increasingly utilizing ultrasound for suspected giant cell arteritis (GCA) or Takayasu arteritis (TAK). This enables direct confirmation of a suspected diagnosis within the examination room without further referrals. Rheumatologists can ask additional questions and explain findings to their patients while performing ultrasound, preferably in fast-track clinics to prevent vision loss. Vascular ultrasound for suspected vasculitis was recently integrated into rheumatology training in Germany. New European Alliance of Associations for Rheumatology recommendations prioritize ultrasound as the first imaging tool for suspected GCA and recommend it as an imaging option for suspected TAK alongside magnetic resonance imaging, positron emission tomography and computed tomography. Ultrasound is integral to the new classification criteria for GCA and TAK. Diagnosis is based on consistent clinical and ultrasound findings. Inconclusive cases require histology or additional imaging tests. Robust evidence establishes high sensitivities and specificities for ultrasound. Reliability is good among experts. Ultrasound reveals a characteristic non-compressible 'halo sign' indicating intima-media thickening (IMT) and, in acute disease, artery wall oedema. Ultrasound can further identify stenoses, occlusions and aneurysms, and IMT can be measured. In suspected GCA, ultrasound should include at least the temporal and axillary arteries bilaterally. Nearly all other arteries are accessible except the descending thoracic aorta. TAK mostly involves the common carotid and subclavian arteries. Ultrasound detects subclinical GCA in over 20% of polymyalgia rheumatica (PMR) patients without GCA symptoms. Patients with silent GCA should be treated as GCA because they experience more relapses and require higher glucocorticoid doses than PMR patients without GCA. Scores based on intima-thickness (IMT) of temporal and axillary arteries aid follow-up of GCA, particularly in trials. The IMT decreases more rapidly in temporal than in axillary arteries. Ascending aorta ultrasound helps monitor patients with extracranial GCA for the development of aneurysms. Experienced sonologists can easily identify pitfalls, which will be addressed in this article.

Cranial involvement in giant cell arteritis

Since its first clinical description in 1890, extensive research has advanced our understanding of giant cell arteritis, leading to improvements in both diagnosis and management for affected patients. Imaging studies have shown that the disease frequently extends beyond the typical cranial arteries, also affecting large vessels such as the aorta and its proximal branches. Meanwhile, advances in comprehending the underlying pathophysiology of giant cell arteritis have given rise to numerous potential therapeutic agents, which aim to minimise the need for glucocorticoid treatment and prevent flares. Classification criteria for giant cell arteritis, as well as recommendations for management, imaging, and treat-to-target have been developed or updated in the last 5 years, and current research encompasses a broad spectrum covering basic, translational, and clinical research. In this Series paper, we aim to discuss the current understanding of giant cell arteritis with cranial manifestations, describe the clinical approach to this condition, and explore future directions in research and patient care.

Large vessel giant cell arteritis

Giant cell arteritis is the principal form of systemic vasculitis affecting people over 50. Large-vessel involvement, termed large vessel giant cell arteritis, mainly affects the aorta and its branches, often occurring alongside cranial giant cell arteritis, but large vessel giant cell arteritis without cranial giant cell arteritis can also occur. Patients mostly present with constitutional symptoms, with localising large vessel giant cell arteritis symptoms present in a minority of patients only. Large vessel giant cell arteritis is usually overlooked until clinicians seek to exclude it with imaging by ultrasonography, magnetic resonance angiography (MRA), computed tomography angiography (CTA), or [18F]fluorodeoxyglucose-PET-CT. Although the role of imaging in treatment monitoring remains uncertain, imaging by MRA or CTA is crucial for identifying aortic aneurysm formation during patient follow up. In this Series paper, we define the large vessel subset of giant cell arteritis and summarise its clinical challenges. Furthermore, we identify areas for future research regarding the management of large vessel giant cell arteritis.

Incidence and clinical manifestations of giant cell arteritis in Spain: results of the ARTESER register

OBJECTIVE

This study aimed to estimate the incidence of giant cell arteritis (GCA) in Spain and to analyse its clinical manifestations, and distribution by age group, sex, geographical area and season.

METHODS

We included all patients diagnosed with GCA between 1 June 2013 and 29 March 2019 at 26 hospitals of the National Health System. They had to be aged ≥50 years and have at least one positive results in an objective diagnostic test (biopsy or imaging techniques), meet 3/5 of the 1990 American College of Rheumatology classification criteria or have a clinical diagnosis based on the expert opinion of the physician in charge. We calculated incidence rate using Poisson regression and assessed the influence of age, sex, geographical area and season.

RESULTS

We identified 1675 cases of GCA with a mean age at diagnosis of 76.9±8.3 years. The annual incidence was estimated at 7.42 (95% CI 6.57 to 8.27) cases of GCA per 100 000 people ≥50 years with a peak for patients aged 80-84 years (23.06 (95% CI 20.89 to 25.4)). The incidence was greater in women (10.06 (95% CI 8.7 to 11.5)) than in men (4.83 (95% CI 3.8 to 5.9)). No significant differences were found between geographical distribution and incidence throughout the year (p=0.125). The phenotypes at diagnosis were cranial in 1091 patients, extracranial in 337 patients and mixed in 170 patients.

CONCLUSIONS

This is the first study to estimate the incidence of GCA in Spain at a national level. We found a predominance among women and during the ninth decade of life with no clear variability according to geographical area or seasons of the year.

Differentiation Between Disseminated Carcinomatosis of the Bone Marrow From Urothelial Cancer and Intravascular Large B-cell Lymphoma: A Case Report

This case report describes a rare case of intravascular large B-cell lymphoma (IVLBCL), initially presenting with nonspecific symptoms of fever and fatigue, and tentatively diagnosed as disseminated carcinomatosis of the bone marrow originating from urothelial cancer in an 80-year-old woman. The patient's journey began with symptoms treated as common ailments and progressed through multiple differential diagnoses, including giant cell arteritis, TAFRO (thrombocytopenia, anasarca, fever, reticulin fibrosis, and organomegaly) syndrome, and disseminated carcinomatosis of the bone marrow originating from urothelial cancer due to the presence of systemic inflammation, anasarca, and elevated soluble interleukin 2 receptor levels, indicative of an intense immunological response. Despite initial treatments, her condition deteriorated, leading to further investigations that ultimately revealed the presence of malignant cells in the urine and bone marrow, confirming the diagnosis of IVLBCL. This case underscores the diagnostic challenges faced when elderly patients present with systemic inflammation and the critical need for thorough investigation beyond initial impressions. It highlights the importance of considering differentiation between disseminated carcinomatosis of the bone marrow and IVLBCL in the differential diagnosis of persistent inflammation, especially in cases where common causes have been excluded and the primary malignancy is not immediately apparent.

Visual manifestations in giant cell arteritis: identification of risk factors from the ARTESER Registry

OBJECTIVE

To determine the prevalence and predictive factors of visual manifestations in a large registry of patients with GCA.

METHODS

ARTESER is a large Spanish multicentre registry supported by the Spanish Society of Rheumatology. It includes patients with GCA from across the entire country diagnosed between June 2013 and March 2019. The variables collected at diagnosis were demographics, clinical manifestations (including all visual manifestations), laboratory, temporal artery biopsy, and imaging findings (ultrasound, FDG-PET/CT, MRI angiography, CT angiography). Patients with and without visual involvement were compared in a bivariate analysis. Multivariate logistic regression was performed to determine potential predictive factors of visual manifestations.

RESULTS

The study population comprised 1636 GCA patients, of whom 599 (36.6%) presented visual manifestations. Anterior ischemic optic neuropathy was the most frequent (n = 274 of 599; 45.7%) ocular complication. The independent predictors that increased the risk (OR; 95% confidence interval) of visual involvement were older age (1.027; 1.009-1.045) and jaw claudication (1.724; 1.325-2.243). The variables associated with a reduced risk were polymyalgia rheumatica (0.541; 0.414-0.708), fever (0.373; 0.264-0.527), longer symptom duration (0.946; 0.909-0.985), and higher erythrocyte sedimentation rate (ESR) (0.992; 0.988-0.997), common features of patients with large vessel-GCA.

CONCLUSION

One-third of GCA patients present visual manifestations at diagnosis. Older age and jaw claudication are independent predictors of visual manifestations, whereas polymyalgia rheumatica, fever, longer symptom duration, and high ESR reduce the risk of visual involvement.

Giant cell temporal arteritis: a clinicopathological study with emphasis on unnecessary biopsy

Introduction

Temporal artery (TA) biopsy is commonly used for the diagnosis of giant cell arteritis (GCA). However, a positive biopsy is no longer mandatory for diagnosis. This study aims to correlate the histopathological findings of TA biopsies in suspected cases of GCA to the clinical presentation in an ophthalmic tertiary eye care center to draw useful conclusions and advocate the possible implementation of guidelines for TA biopsy.

Methods

Data was collected from patients' medical records including, demographics, clinical data, and histopathological findings and diagnosis. The 2022 American College of Rheumatology/ European Alliance of Associations for Rheumatology (ACR/EULAR) criteria have been used and partially adopted as a guide to compare the variables between TA biopsy-positive and negative groups as well as the TA biopsy-positive group and the group of patients with TA biopsy showing atherosclerosis.

Results

Out of the total 35 patients who underwent a TA biopsy during the period of 23 years, 22.9% of patients had histopathological findings consistent with GCA and 42.9% had TA atherosclerotic changes, while the remaining 34.3% had histologically unremarkable TA. The mean age of all patients was 66 ± 10.9 years. Slightly more than half were females (54.3%) and the remaining were males (45.7%). In the group with positive TA biopsies, the mean age was 71 ± 8.4 years with a higher female predominance (female-to-male ratio of 5:3). The mean diagnostic clinical score used in our study was higher (7.5 ± 2.33) in the GCA-positive group when compared to the other groups with statistical significance (mean of 4.85 ± 2.01 in patients with overall GCA-negative biopsies and 5.13 ± 2.10 in the group with atherosclerosis). Other three clinical variables that were found to be statistically significant in the GCA biopsy-positive group were scalp tenderness, jaw claudication, and optic nerve pallor.

Discussion

The mean age (71 ± 8.4 years) and the female predominance of GCA in our group of patients with positive TA biopsy (62.5%) was like other reports. In our study 22.9% of performed TA biopsies over the period of the study were positive confirming the diagnosis of GCA on histological exam, which was similar to another report and is considered to be relatively low. The incorporation of increased clinically focused assessments and algorithms, with the aid of the ACR/EULAR criteria, may decrease the frequency of TA biopsies that carries unnecessary cost and risk of procedure-related morbidity. We highly recommend applying the age of ≥ 50 years as an initial criterion for diagnosis, followed by the consideration of the statistically significant clinical features: scalp tenderness, jaw claudication, and optic nerve pallor.

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

Introduction

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.

Methods

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.

Results

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.

Conclusion

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.

Performance of the new 2022 ACR/EULAR classification criteria for giant cell arteritis in clinical practice in relation to its clinical phenotypes

BACKGROUND

To examine the performance of the new 2022 American College of Rheumatology (ACR)/EULAR classification criteria for giant cell arteritis (GCA) in routine clinical care, compared with the 1990 ACR GCA classification criteria.

METHODS

The fulfilment of 2022 ACR/EULAR and 1990 ACR criteria was tested in our real-life cohort of GCA patients with proven vasculitis by temporal artery biopsy or imaging (a necessary pre-requisite to apply the new criteria is the presence of a confirmed diagnosis of medium- or large-vessel vasculitis). The performance of classification criteria was evaluated in all patients with GCA across different subsets of the disease. Patients with GCA were compared with unselected controls with suspected GCA.

RESULTS

A total of 136 patients with proven GCA were identified. The new criteria had a sensitivity of 92.6% and a specificity of 85.2%. According to the clinical phenotypes, the sensitivity was 98.8% in cranial GCA, 92% in extracranial large vessel (LV) GCA and 75% in occult systemic GCA. These data are much better than those observed with the 1990 ACR classification criteria, which showed a sensitivity of 66.1% and a specificity of 85.1% for the total sample, with a sensitivity of 89.1% in cranial GCA, 24% in extracranial LV-GCA and 35.7% in occult systemic GCA. Ten (7.4%) patients in our cohort did not fulfil either of the criteria sets (8 with occult systemic GCA and 2 with extracranial LV-GCA). The sensitivity of the new criteria in patients with occult systemic and extracranial LV-GCA could be greatly improved assigning more weight (3 points) to some imaging findings (axillary involvement and FDG-PET activity throughout the aorta).

CONCLUSION

Our study confirms that the new classification criteria are more sensitive in real-life settings than the old ACR criteria across all clinical phenotypes.

External validation of the 2022 ACR/EULAR classification criteria in patients with suspected giant cell arteritis in a Dutch fast-track clinic

OBJECTIVE

Recently the Diagnostic and Classification Criteria in Vasculitis Study group developed and published new American College of Rheumatology/EULAR classification criteria for giant cell arteritis (GCA). To test robustness in a different clinical setting and inform clinicians on performance in clinical practice, we aim to externally validate them in patients with a suspicion of GCA referred to our GCA fast-track clinic.

METHODS

Patients with suspected GCA from the Hospital Group Twente Early GCA in Twente prospective cohort were included. The clinical diagnosis of GCA verified after 6 months of follow-up made by the treating rheumatologist was used as a reference standard. A cut-off score of ≥6 was tested as described in the original article. Area under the receiver operating characteristics curve, sensitivity and specificity were calculated.

RESULTS

In total, 133 patients with suspected GCA were included, of whom 53 were diagnosed with GCA and 80 patients were not diagnosed with GCA. The area under the curve (AUC) was 0.96 (95% CI 0.92 to 0.98). Using the proposed cut-off score of≥6, we found that sensitivity was 98.0% (95% CI 89.9% to 100%) and specificity was 57.5% (95% CI 45.9% to 68.5%). The majority of misclassified patients without GCA had classification scores of 6 and 7 as clinical and/or laboratory criteria were often present in our non-GCA population.

CONCLUSION

Our results showed an excellent AUC and sensitivity with a moderate specificity for classification of GCA patients. Considering our relevant study population, we found that the new classification criteria might also be useful for diagnostic purposes, albeit with careful interpretation.