Vessel wall MRI in giant cell arteritis: standardized protocol and scoring approach developed by an international working group.

OBJECTIVES: There are an increasing number of centers performing research on high-resolution vessel wall magnetic resonance imaging (VW-MRI) in giant cell arteritis (GCA). However, harmonized approaches to VW-MRI in GCA are lacking and are essential to performing multicentre studies. Using a data-driven, consensus-based approach, an international expert group developed a standardized MRI protocol and scoring system to advance multi-centered research in cranial GCA. METHODS: A targeted literature review of VW-MRI in cranial GCA was conducted. A working group comprised of radiologists, rheumatologists, and ophthalmologists with expertise in VW-MRI and GCA reviewed the results of the literature search, presented relevant data and images from their respective centers, and then reached consensus on recommendations related to key MRI structures, MRI sequences, scoring system, and other important considerations. RESULTS: A total of 21 relevant articles were identified and reviewed. Based on published literature, structures to be evaluated on MRI were categorized based on anatomic location (extradural cranial, intradural cranial, and orbits) and prioritization (core vs elective). Essential and elective sequences to comprehensively image cranial and orbital structures while minimizing scan time were determined along with scoring systems to grade contrast enhancement. CONCLUSION: This report describes a standardized approach to facilitate research of VW-MRI in cranial GCA that is the result of a multi-disciplinary, international collaboration of experts in VW-MRI and/or GCA.

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.

Genes deregulated in giant cell arteritis by Nanostring nCounter gene expression profiling in temporal artery biopsies.

OBJECTIVE: To identify differentially expressed genes in temporal artery biopsies (TABs) from patients with giant cell arteritis (GCA) with different histological patterns of inflammation: transmural inflammation (TMI) and inflammation limited to adventitia (ILA), compared with normal TABs from patients without GCA. METHODS: Expression of 770 immune-related genes was profiled with the NanoString nCounter PanCancer Immune Profiling Panel on formalin-fixed paraffin-embedded TABs from 42 GCA patients with TMI, 7 GCA patients with ILA and 7 non-GCA controls. RESULTS: Unsupervised clustering of the samples revealed two distinct groups: normal TABs and TABs with ILA in one group, 41/42 TABs with TMI in the other one. TABs with TMI showed 31 downregulated and 256 upregulated genes compared with normal TABs; they displayed 26 downregulated and 187 upregulated genes compared with TABs with ILA (>2.0 fold changes and adjusted p values <0.05). Gene expression in TABs with ILA resembled normal TABs although 38 genes exhibited >2.0 fold changes, but these changes lost statistical significance after Benjamini-Yekutieli correction. Genes encoding TNF superfamily members, immune checkpoints, chemokine and chemokine receptors, toll-like receptors, complement molecules, Fc receptors for IgG antibodies, signalling lymphocytic activation molecules, JAK3, STAT1 and STAT4 resulted upregulated in TMI. CONCLUSIONS: TABs with TMI had a distinct transcriptome compared with normal TABs and TABs with ILA. The few genes potentially deregulated in ILA were also deregulated in TMI. Gene profiling allowed to deepen the knowledge of GCA pathogenesis.

The primary systemic vasculitis associated optic neuritis: a retrospective analysis in a single center over 10 years.

OBJECTIVES: To investigate the clinical and image characteristics of primary systemic vasculitis-associated optic neuritis patients. METHODS: This is a retrospective study. The patients clinically diagnosed with primary system vasculitis-induced optic neuritis were recruited from March 2013 to December 2023. All cases received orbital magnetic resonance imaging scans were analyzed. The ocular findings, systemic manifestations, laboratory data and prognosis were reviewed retrospectively. In addition, the related literature was reviewed. RESULTS: Fourteen patients (21 eyes), including 10 men and 4 women, were enrolled in this study. The ages ranged from 30 to 86 years in this cohort. Orbits MRI detects the enlargement and/or enhancement of the optic nerve. Cases 1-5 reported a confirmed diagnosis of Takayasu's arteritis, and cases 6-8 had giant cell arteritis. Cases 9-13 were antineutrophil cytoplasmic antibody-associated vasculitis. Case 14 was Cogan's syndrome. Mult organs and tissues, such as the kidneys, heart, paranasal sinuses, meninges, and respiratory system, were involved. In all of the 14 involved patients, the disease onset was either during the fall or winter season. There were no or only slight improvements in visual activity after conventional therapies. CONCLUSIONS: The autoantibodies' attack on the optic nerve, ischemic damage, or destruction of the blood-brain barrier may be the potential pathogenesis of vasculitis-associated optic neuritis. Even with prompt and aggressive clinical interventions, the prognosis remains unsatisfactory.

[News on the treatment of large vessel vasculitis]. / Neues zur Therapie von Großgefäßvaskulitiden.

Large vessel vasculitis, such as giant cell arteritis (GCA) and Takayasu arteritis (TAK) are primarily manifested on large and medium-sized arteries. While GCA mainly affects older people after the 6th decade of life onwards, TAK mainly affects young women under the age of 40 years. Glucocorticoids (GC) are still the standard treatment for both diseases. Refractory courses and relapses in particular often lead to long-term treatment with high cumulative doses of GC, which can lead to increased morbidity and mortality. To date, only the interleukin 6 (IL-6) receptor blocker tocilizumab has been approved for the treatment of GCA. The data on methotrexate and other conventional immunosuppressants are incomplete and in some cases contradictory. The early use of steroid-sparing immunosuppressants is recommended for TAK, although the number of randomized placebo-controlled trials is limited and no steroid-sparing treatment has yet been approved for TAK. For both diseases there is still a great need for modern and safe steroid-sparing treatment that effectively treats vasculitis, prevents damage and enables adequate disease monitoring. This article provides an overview of the current study situation and possible future treatment options for GCA and TAK.

The role of 18FDG-PET imaging in VEXAS syndrome: a multicentric case series and a systematic review of the literature.

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, and somatic) syndrome is characterized by heterogeneous clinical manifestations. Due to the inflammatory nature of this condition, 18-FDG-PET (18-fluorodeoxyglucose-positron emission tomography) might be used to diagnose and monitor the disease. However, no data are available about the most common findings of PET imaging in this disease. For this reason, we summarised all the available reports of patients with VEXAS who underwent at least one PET scan and described 8 additional patients' PET from our centres. Overall, we described 35 patients' PET findings. All patients were male, with a median age of 70 years. The most frequent hypermetabolic sites on PET scans were the bone marrow (77.1%), lymph nodes (35.3%), lungs (28.6%), spleen and large vessels (22.9%), and cartilage (20%). Six patients underwent a PET scan 2.7 ± 1.5 years before VEXAS diagnosis, showing nonspecific uptake in the bone marrow. Four patients had a follow-up PET scan, showing a decrease or a disappearance of the previously identified hypermetabolic areas. In conclusion, although no specific uptake site has been found for VEXAS syndrome, PET imaging could help detect inflammatory foci that are not clinically evident. In addition, high metabolic activity in bone marrow might precede the clinical onset of the disease, shedding light on the pathogenesis of VEXAS.

Giant-cell arteritis on photon-counting detector CT: A case report.

A 77-year-old woman presented to our hospital with a 2-week history of fever, headache, and induration along the bilateral superficial temporal arteries (STAs). The color Doppler ultrasonography of the STA showed a hypoechoic mural thickening surrounding a residual color flow. A contrast-enhanced photon-counting detector (PCD) CT demonstrated mural thickening and stenosis of the bilateral STAs. The patient underwent a biopsy of the right STA. Histopathological findings were consistent with giant cell arteritis (GCA). The patient's symptoms were temporarily relieved after initiation of steroid treatment, but jaw claudication occurred 2 months later. Contrast-enhanced CT showed improved vascular abnormalities of the STAs but new mural thickening and stenosis of the bilateral maxillary artery. Due to its higher resolution, image contrast, and lower noise, PCD-CT may have great potential in detecting, diagnosing, and monitoring GCA.

An unusual cause of headache: Expanding your differential.

Giant cell arteritis (GCA) is an inflammatory vasculitis that affects larger blood vessels, like the temporal arteries and the aorta. It is systemic and tends to affect individuals over 50. Common symptoms include headache, jaw pain provoked by chewing, and fever. We present an interesting case of a GCA variant.

Influenza A infection as a potential trigger of giant cell arteritis: A case report.

Presenting as a large vessel vasculitis, giant cell arteritis (GCA) manifests with various symptoms, including fever, myalgias, headache, and jaw claudication. Although the precise pathogenesis of GCA remains incompletely elucidated, there is speculation about the involvement of environmental factors and infectious agents like bacteria and viruses in its development. Nevertheless, data on the potential link between influenza infection and GCA are limited. In this report, we present the case of an 88-year-old patient diagnosed with GCA following a severe influenza A infection.

Retrospective Analysis of Specimen Quality in Temporal Artery Biopsies for Giant Cell Arteritis and Disease Association in North Midlands, England.

Background Temporal artery biopsy (TAB) is the recommended index diagnostic method for giant cell arteritis (GCA). Per the British Society for Rheumatology (BSR) guidelines, we assessed our procedural performance. Additionally, we evaluated the occurrence of GCA diagnosis in immunosuppressed patients and other comorbidities. Methods Following the audit registration, a retrospective analysis of prospectively collected data was conducted from 2017 to 2022 at a large university hospital in North Midlands, England. Data on demographics and comorbidities were gathered. The study's primary outcome was adherence to BSR guidelines and our service provisions. Secondary outcomes included examining the relationship between biopsy-confirmed GCA and other comorbidities. Statistical analysis was carried out using SPSS version 29 (IBM Corporation, Armonk, New York, United States of America). Two-sample t-test and Chi-square/Fisher exact test were used for continuous and categorical variables, respectively. Holm-Bonferroni method was incorporated to adjust for multiple comparisons. Results A total of 156 patients who underwent temporal artery biopsy (TAB) were included in the study, with a male-to-female ratio of 0.44:1. The median age was 73. Among the patients, 19% were smokers. The procedures were performed by either a vascular surgeon (119, 76%) or by an ophthalmologist (37, 24%). Two-thirds of the patients underwent TAB within seven days of referral. In 73, 47% of cases, the post-fixation biopsy sample size exceeded 10 mm. Positive biopsy results were found in 45 patients (29%). GCA was confirmed in 39% of patients with polymyalgia rheumatica (PMR), 24% with diabetics, 20% with hypothyroidism, 29% with hypertension, 32% with hyperlipidaemia, and 26% with other inflammatory diseases. However, the p-value was below the statistically significant threshold. The biopsy outcome was also not dependent on the speciality, time from referral to biopsy, nor on the length of the post-fixation specimen. Conclusions Temporal artery biopsy remains a valuable and crucial diagnostic tool in challenging equivocal cases of giant cell arteritis (GCA), although it is limited by its sensitivity, but there is also room for improvement. There is still uncertainty regarding the relationship between biopsy positivity, post-fixation sample size, and the interval between referral and procedure. Additionally, the speciality of the clinician performing the biopsy does not appear to significantly influence the likelihood of a positive result. We still do not fully understand why this is, but the association of the GCA with other comorbidities was unpredictably insignificant.

Clinical features, imaging use, and management in giant cell arteritis: a retrospective single-center study.

This study examines the characteristics of patients with giant cell arteritis (GCA), the utilization of imaging in GCA diagnosis, and variations in GCA management among specialties. Subjects were identified from the Dallas VAMC database spanning 2010 to 2021 using ICD-9/10 codes for GCA and polymyalgia rheumatica, and a list of temporal artery biopsies (TAB). Patients lacking sufficient data to meet the ACR 1990 classification criteria for GCA were excluded. Categorical variables were compared using Fisher's exact test. Continuous variables were analyzed with the Kruskal-Wallis test. Among 209 identified patients, 41 were excluded due to insufficient data for ACR classification. The cohort comprised 91.9% males with a median age of 69. Of the remaining 168 patients, 42 received a final diagnosis of GCA, and 15 of these were confirmed with a positive TAB. The most reported initial symptoms were visual disturbances (75.5%) and headaches (67.7%). Ophthalmology was the initial physician for 46% of patients. GCA correlated with co-existing autoimmune diseases, glucocorticoid-sparing treatments, and consultation with a rheumatologist (p < 0.05). There were no significant differences in clinical features or management of the positive and negative TAB GCA groups. GCA presents with heterogeneous symptoms making diagnosis challenging. Scalp tenderness and headaches were significantly higher in GCA patients, but sub-group analysis revealed no significant differences among GCA patients. Vascular assessments and adjunct imaging modalities are underutilized. The establishment of multidisciplinary or fast-track clinics may enhance the optimization of GCA management. Key Points • The most common presenting symptoms were blurry vision/visual loss (75.5%), headache (67.7%), and scalp tenderness (35.9%) in descending order. • In sub-group analysis, no significant differences were found between GCA sub-groups, but when compared to the non-GCA group, were found to have significantly higher rates of headache and scalp tenderness. • Compared to other specialties, rheumatologists were more likely to use advanced imaging, and to prescribe glucocorticoid-sparing treatments. • Systematic and comprehensive assessment and multidisciplinary approach could improve diagnosis and management.

[News on the imaging of large vessel vasculitis]. / Neues in der Bildgebung von Großgefäßvaskulitiden.

Large vessel vasculitis, including giant cell arteritis (GCA) and Takayasu arteritis (TAK), are autoimmune diseases primarily affecting the aorta and its branches. GCA is the most common primary vasculitis. Inflammatory changes in the vessel walls can cause serious complications such as amaurosis, stroke, and aortic dissection and rupture. Imaging techniques have become an integral part for the diagnosis and monitoring of large vessel vasculitis, allowing for effective disease monitoring. GCA and TAK exhibit similar patterns of vascular distribution. However, the temporal arteries are never involved in TAK, and axillary arteritis occurs more frequently in GCA. In most centers, ultrasound of the temporal and axillary arteries has replaced temporal artery biopsy as the primary diagnostic tool for GCA. In addition to ultrasound, magnetic resonance imaging (MRI), computed tomography (CT), and [18F]-FDG (fluorodeoxyglucose) positron emission tomography-computed tomography (PET) are important, particularly for visualizing the aorta. Moreover, PET-CT is now also capable of assessing the temporal arteries, although it is not yet widely available. In polymyalgia rheumatica (PMR), ultrasound of the shoulder and hip regions is part of the ACR/EULAR classification criteria. MRI allows detailed visualization of additional inflammatory extraarticular manifestations, showing characteristic inflammatory lesions in entheses, tendons, and ligaments. [18F]-FDG-PET-CT also enables the visualization of musculoskeletal inflammation, especially in the shoulder and hip regions, as well as paravertebral areas. Ultrasound can detect subclinical GCA in up to 23% of patients with PMR, which should be treated like GCA. Technological innovations such as new radiotracers and improved MRI imaging could further enhance the diagnosis and monitoring of large vessel vasculitis and PMR, thus playing a crucial role in improving the prognosis through faster initiation of therapy.

Ultrasonography led multimodal diagnostic pathway for giant cell arteritis.

OBJECTIVES: To establish the sensitivity and negative predictive value of a multimodal pathway incorporating ultrasonography, 18-fluorodeoxyglucose labelled positron emission tomography computed tomography and temporal artery biopsy for the diagnosis of giant cell arteritis. METHODS: 1000 consecutive referrals for a new diagnosis of giant cell arteritis were analysed. All patients had a protocolized examination. Patients with a negative ultrasonography and a C-reactive protein of ≥ 20 mg/l received an extended ultrasound examination. If that was negative, and there was no other explanation for their presentation, a second test in the form of either a temporal artery biopsy or an 18-fluorodeoxyglucose labelled positron emission tomography computed tomography was offered. We calculated the sensitivity and negative predictive value of the interventions for diagnosing giant cell arteritis. RESULTS: 279/1000 patients had positive ultrasonography for giant cell arteritis. 202 had bilateral superficial temporal arterial involvement. Ultrasonography of the axillary artery and other head/neck arteries increased the yield by 53 and 24 patients respectively. 181 patients were referred for a second test. 24/139 temporal artery biopsies and 7/42 18-fluorodeoxyglucose labelled positron emission tomography computed tomography scans were positive. The sensitivity and negative predictive value rise from 62.3% and 84.7% respectively for imaging superficial temporal arteries alone, to 95.7% and 98.0% respectively for extended ultrasonography plus a second test. CONCLUSIONS: This is the first real world evidence of the utility of ultrasonography for the diagnosis of giant cell arteritis as part of a multimodal diagnostic pathway.

Intraoperative Frozen Section Diagnosis of Giant Cell Arteritis.

Giant cell arteritis (GCA) is a systemic vasculitis of medium and large vessels that is diagnosed using temporal artery biopsy (TAB). In this case report, we explored the benefits of frozen section analysis as a rapid intraoperative diagnostic technique for GCA. We present the cases of two patients who underwent TAB with frozen section analysis, to demonstrate the value of this technique in initiating immediate treatment and potentially avoiding unnecessary contralateral biopsies when the frozen section of the first biopsy confirms GCA. We recommend further investigation into the use of frozen section analysis for patients suspected of having GCA, who might otherwise undergo bilateral TAB.

The Importance of Early Recognition of Rare Ischaemic Complications of GCA to Prevent Permanent Vision Loss.

Scalp and tongue necrosis are rare ischemic manifestations of giant cell arteritis (GCA). Early recognition of these conditions is crucial to preventing permanent visual loss (PVL). We present two cases of scalp and tongue necrosis, respectively, where a delay in diagnosis resulted in irreversible vision loss and severe complications. These cases highlight the importance of educating non-rheumatologists about these manifestations to ensure prompt steroid treatment, which can prevent vision loss and reduce morbidity in GCA patients.

Optic nerve sheath measurement to monitor disease activity in giant cell arteritis: a pilot study.

INTRODUCTION/OBJECTIVES: Optic nerve sheath (ONS) enhancement using magnetic resonance imaging of the orbits was observed in patients with giant cell arteritis (GCA). We previously showed that ONS diameter (ONSD) by bedside ultrasound is increased in patient with active GCA. This study aims to assess whether ONSD decreases with clinical remission in patients with GCA. METHODS: A prospective cohort study was conducted from June 2022 to January 2023. Patients who had an optic nerve ultrasound at GCA diagnosis as part of a previous crosssectional study were eligible. Optic nerve ultrasound was performed by the same investigator at diagnosis and month 3. ONSD (includes the optic nerve and its sheath) and optic nerve diameter (OND) were measured. Descriptive statistics for baseline characteristics and paired sample t-test were performed to assess the mean difference in OND and ONSD between diagnosis and month 3. RESULTS: Nine patients with GCA were included. The median age at disease onset was 79 years (interquartile range (IQR) of 79-82 years), and 7 patients were males. All patients were in clinical remission at month 3 on prednisone (median dose of 15 mg/day, IQR of 10-25 mg). The mean ONSD was lower at month 3 (3.76 mm) compared to baseline (5.98 mm), with a paired mean difference of 2.22 mm (95% CI 1.41-3.03 mm, p < 0.001). As anticipated, OND measurements did not vary between diagnosis and month 3. CONCLUSION: ONSD on ultrasound improves after 3 months of therapy in patients with GCA. A longer prospective study is required to determine if ONSD is useful to assess disease activity in GCA. Key Points • ONS ultrasound can identify patients with active GCA. • The ONSD on ultrasound is dynamic and improved after 3 months of GCA therapy. • ONS ultrasound may be useful to monitor disease activity in GCA.

Stroke pattern in giant-cell arteritis mostly involves watershed areas.

CONTEXT: Stroke related to giant cell arteritis (GCA) is rare and is associated with a poor outcome. One of the putative ischemic mechanisms is narrowing of the arterial lumen due to wall infiltration by inflammation and intimal proliferation, leading to reduced distal blood flow. It was hypothesized that GCA-related stroke could predominate in watershed areas (WA). METHODS: Literature review including all cases of GCA-related stroke with brain images. RESULTS: Among 75 cases of GCA-related stroke, the anterior and posterior territories were involved in 48 % and 62.6 %, respectively. Up to 88.9 % of cases of anterior stroke probably involved WA. WA lesions in the posterior territories were as follows: uni/bilateral middle cerebellar peduncle (MCP) lesions in 25.5 %, and with less confidence, non-wedge-shaped cerebellar lesions in 46.8 %, or combined lesions in 61.7 %. Stenosis or occlusion of the afferent artery was almost always observed. A few lesions were not easily explained by low flow. DISCUSSION: Despite the limitations of arterial territory allocation especially in the posterior circulation, ischemic lesions mainly occurred in WA. MCP lesions, which were typically WA, were highly characteristic of GCA. Low flow downstream focal stenosis was the main, but not the unique, ischemic mechanism of GCA stroke.

Vascular ultrasound as a follow-up tool in patients with giant cell arteritis: a prospective observational cohort study.

Objectives: To evaluate relapses in giant cell arteritis (GCA), investigate the utility of vascular ultrasound to detect relapses, and develop and assess a composite score for GCA disease activity (GCAS) based on clinical symptoms, ultrasound imaging activity, and C-reactive protein (CRP). Methods: Patients with GCA were prospectively followed with scheduled visits, including assessment for clinical relapse, protocol ultrasound examination, and CRP. At each visit, patients were defined as having ultrasound remission or relapse. GCAS was calculated at every visit. Results: The study included 132 patients, with a median follow-up time of 25 months [interquartile range (IR) 21]. The clinical relapse rate was 60.6%. There were no differences in relapse rates between GCA subtypes (cranial-GCA, large vessel (LV)-GCA, and mixed-GCA) (p = 0.83). Ultrasound yielded a sensitivity of 61.2% and a specificity of 72.3% for diagnosing GCA- relapse in our cohort. In 7.7% of follow-up visits with clinical relapses, neither high CRP nor findings of ultrasound relapse were registered. In comparison, in 10.3% of follow-up visits without symptoms of clinical relapse, there were both a high CRP and findings of ultrasound relapse. Conclusion: We found moderate sensitivity and specificity for ultrasound as a monitoring tool for relapse in this prospective cohort of GCA patients. The extent or subtype of vasculitis at the diagnosis did not influence the number of relapses. Based on a combination of clinical symptoms, elevated CRP, and ultrasound findings, a composite score for GCA activity is proposed.

Giant cell arteritis and therapeutic response: a dual facet of immunotherapy in metastatic clear cell renal carcinoma.

Immune checkpoint inhibitors have emerged as a promising cancer treatment, allowing significant and long-term therapeutic responses. Nivolumab, an anti-programmed cell death protein-1, is one of the molecules of this therapeutic class with known and manageable side effects. Giant cell arteritis is a rare immune-related adverse event most often manifested by headaches poorly released by common antalgics and can result in visual loss. We report its occurrence in an 80-year-old patient on maintenance nivolumab for metastatic clear cell renal carcinoma. Prompt diagnosis and initiation of glucocorticoid therapy led to symptom improvement and visual recovery.