The importance of skip lesions in temporal arteritis

Giant Cell Arteritis

Giant cell arteritis (GCA) is the most common primary vasculitis and is associated with potential bilateral blindness. Neither clinical nor laboratory evidence is simple and unequivocal for this disease, which usually requires rapid and reliable diagnosis and therapy. The ophthalmologist should consider GCA with the following ocular symptoms: visual loss or visual field defects, transient visual disturbances (amaurosis fugax), diplopia, eye pain, or new onset head or jaw claudication. An immediate ophthalmological examination with slit lamp, ophthalmoscopy, and visual field, as well as color duplex ultrasound of the temporal artery should be performed. If there is sufficient clinical suspicion of GCA, corticosteroid therapy should be initiated immediately, with prompt referral to a rheumatologist/internist and, if necessary, temporal artery biopsy should be arranged. Numerous developments in modern imaging with colour duplex ultrasonography, MRI, and PET-CT have the potential to compete with the classical, well-established biopsy of a temporal artery. Early determination of ESR and CRP may support RZA diagnosis. Therapeutically, steroid-sparing immunosuppression with IL-6 blockade or methotrexate can be considered. These developments have led to a revision of both the classification criteria and the diagnostic and therapeutic recommendations of the American College of Rheumatologists and the European League against Rheumatism, which are summarised here for ophthalmology.

Estimating overdiagnosis in giant cell arteritis diagnostic pathways using genetic data: genetic association study

OBJECTIVES

Giant cell arteritis (GCA) may be confirmed by temporal artery biopsy (TAB) but false negatives can occur. GCA may be overdiagnosed in TAB-negative cases, or if neither TAB nor imaging is done. We used Human Leucocyte Antigen (HLA) genetic association of TAB-positive GCA as an "unbiased umpire" test to estimate historic overdiagnosis of GCA.

METHODS

Patients diagnosed with GCA between 1990-2014 were genotyped. During this era, vascular imaging alone was rarely used to diagnose GCA. HLA region variants were jointly imputed from genome-wide genotypic data of cases and controls. Per-allele frequencies across all HLA variants with p< 1.0x1 0 -5 were compared with population control data to estimate overdiagnosis rates in cases without a positive TAB.

RESULTS

Genetic data from 663 GCA patients were compared with data from 2619 population controls. TAB-negative GCA (n = 147) and GCA without TAB result (n = 160) had variant frequencies intermediate between TAB-positive GCA (n = 356) and population controls. For example, the allele frequency of HLA-DRB1*04 was 32% for TAB-positive GCA, 29% for GCA without TAB result, 27% for TAB-negative GCA and 20% in population controls. Making several strong assumptions, we estimated that around two-thirds of TAB-negative cases and one-third of cases without TAB result may have been overdiagnosed. From these data, TAB sensitivity is estimated as 88%.

CONCLUSIONS

Conservatively assuming 95% specificity, TAB has a negative likelihood ratio of around 0.12. Our method for utilising standard genotyping data as an "unbiased umpire" might be used as a way of comparing the accuracy of different diagnostic pathways.

Giant cell arteritis: reviewing the advancing diagnostics and management

Giant Cell Arteritis (GCA) is well known to be a critical ischaemic disease that requires immediate medical recognition to initiate treatment and where one in five people still suffer visual loss. The immunopathophysiology has continued to be characterised, and the influencing of ageing in the development of GCA is beginning to be understood. Recent national and international guidelines have supported the directed use of cranial ultrasound to reduce diagnostic delay and improve clinical outcomes. Immediate high dose glucocorticoids remain the standard emergency treatment for GCA, with a number of targeted agents that have been shown in clinical trials to have superior clinical efficacy and steroid sparing effects. The aim of this review was to present the latest advances in GCA that have the potential to influence routine clinical practice.

Utility of biomarkers and temporal artery biopsy length for investigating giant cell arteritis in Western Australia

AIM

To explore demographic characteristics, biopsy length, and blood biomarker performance in an Australian cohort of patients who have undergone temporal artery biopsy (TAB) for giant cell arteritis (GCA).

METHODS

We extracted data on biopsies performed for GCA between January 2016 and December 2020 at public hospitals in Perth. Sensitivity, specificity, and area under the curve (AUC) were calculated for blood results. We evaluated the proportion of biopsies with post-fixation length less than 15 mm and explored several length associations.

RESULTS

We retrospectively reviewed biopsies of 360 patients (65.8% female, mean age 72.1 years). Biopsy-positive patients were older (6.0 years, P < 0.01), and had higher C-reactive protein (CRP) (44.5 mg/L, P < 0.01), erythrocyte sedimentation rate (ESR) (18.9 mm/h, P < 0.01), and platelets (86.8 × 10³ /μL, P < 0.01) compared with biopsy-negative patients. CRP and platelets had the highest AUCs at 0.76 and 0.71, respectively. Sensitivities for CRP and ESR were 96.2% and 91.5%, respectively. Specificities were comparatively low at 41.3% for CRP and 37.4% for ESR. The proportion of biopsies with sub-optimal length was 55.9% and this varied significantly by site (P < 0.01). Smaller sites performed worse, with a sub-optimal biopsy rate of 87% amongst the three smallest sites.

CONCLUSION

ESR and CRP are helpful preliminary investigations, especially in identifying low-risk patients, but their specificity is limited. Smaller centers had a higher proportion of biopsies with sub-optimal length. Considering the importance of biopsy length for TAB diagnostic value, reviewing biopsy data may assist services in developing improvement strategies.

Comparison of temporal artery ultrasound versus biopsy in the diagnosis of giant cell arteritis

BACKGROUND/OBJECTIVES

Giant cell arteritis (GCA) is a medical and ophthalmological emergency due to risk of stroke and sudden irreversible loss of vision. Fast and accurate diagnosis is important to prevent complications and long-term high dose glucocorticoids toxicity. Temporal artery biopsy is gold standard for diagnosing GCA. However, temporal artery ultrasound is a fast and non-invasive procedure which may provide a supplement or an alternative to biopsy. This study assesses the diagnostic performance of ultrasound and biopsy in the diagnosis of GCA.

SUBJECTS/METHODS

Examination results of patients suspected of having GCA in the period from August 2018 to June 2019 were reviewed. Patients underwent clinical examination and blood tests. Within a few days of starting glucocorticoid treatment, temporal ultrasound and unilateral biopsy were performed. Experienced physicians established the final clinical diagnosis at 6-months follow-up.

RESULTS

Seventy-eight patients underwent both ultrasound and biopsy. Thirty-five (45%) received the final clinical diagnosis of GCA. Compared with the final clinical diagnosis, biopsy had a sensitivity of 69% (51-83%) and a specificity of 100% (92-100%), and ultrasound a sensitivity of 63% (45-79%) and a specificity of 79% (64-94%). Area under the receiver operating characteristics curves were 0.84 and 0.71 for biopsy and ultrasound respectively (p = 0.048). False negative rate of ultrasound was 4 out of 78 (5%).

CONCLUSION

Sensitivity of ultrasound is almost on par with that of biopsy although the overall diagnostic accuracy of ultrasound was slightly lower. We find that ultrasound is a reliable tool for first line diagnosis of GCA.

Optimizing the use of temporal artery biopsy: a retrospective study

BACKGROUND

Giant cell arteritis is an inflammatory disease of the large- and medium-sized vessels. It is the most common primary vasculitis, with lifetime incidences of 0.5% and 1% in men and women, respectively. Its diagnosis is based upon clinical criteria, which may include temporal artery biopsy. Expected positivity rates of temporal artery biopsies and patient selection remain controversial topics in the literature.

METHODS

A cross-sectional retrospective study of 127 patients referred for temporal artery biopsy with a diagnosis of suspected giant cell arteritis between January 2014 and December 2018 was performed. The primary outcome was the positivity rate. The relationships between positivity rates, symptoms, clinical suspicion, biopsy delay, biopsy length and corticosteroid treatment were also studied.

RESULTS

A positivity rate of 23.7% (16.6-32.6%) was shown, along with a significant association between jaw claudication and specimen positivity (odds ratio 8.1, p < 0.05). Moreover, there were significant associations between a high initial clinical suspicion of disease and specimen positivity (p < 0.05), as well as a high initial clinical suspicion of disease and pursuit of corticosteroid treatment following biopsy results, regardless of positivity (p < 0.05). The duration of corticosteroid treatment prior to biopsy was not associated with a change in positivity rate.

CONCLUSIONS

The positivity rate of temporal artery biopsy was 23.7%. Treatment of patients with negative temporal artery biopsy was associated with maintenance of corticosteroid treatment when the initial clinical suspicion of arteritis was high. Therefore, temporal artery biopsy may not be necessary for patients with a high initial clinical suspicion of giant cell arteritis.

Evaluation of Arterial Histopathology and microRNA Expression That Underlie Ultrasonography Findings in Temporal Arteries of Patients with Giant Cell Arteritis

The aim of this study was to assess the interrelation between vascular ultrasonography (US) findings, histopathological data, and the expression of selected dysregulated microRNAs (miRNAs) in giant cell arteritis (GCA). The study included data on the clinical parameters, US measurements, and temporal artery biopsies (TABs) of 46 treatment-naïve patients diagnosed with GCA and 22 age-matched non-GCA patient controls. We performed a comprehensive comparative and correlation analysis along with generation of receiver operating characteristic (ROC) curves to ascertain the diagnostic performance of US examination parameters and selected miRNAs for GCA diagnosis. We showed significant differences in the US-measured intima-media thickness of the temporal arteries, the presence of a halo sign, and the presence of luminal stenosis between GCA-positive/TAB-positive, GCA-positive/TAB-negative, and non-GCA patients. Correlation analysis revealed significant associations between several histopathological parameters, US-measured intima-media thickness, and the halo sign. We found that the significant overexpression of miR-146b-5p, miR-155-5p, miR-511-5p, and miR-21-5p, and the under-expression of the miR-143/145 cluster, miR-30a-5p, and miR-125a-5p, coincides and is associated with the presence of a halo sign in patients with GCA. Notably, we determined a high diagnostic performance of miR-146b-5p, miR-21-3p, and miR-21-5p expression profiles in discriminating GCA patients from non-GCA controls, suggesting their potential utilization as putative biomarkers of GCA. Taken together, our study provides an insight into the US-based diagnostic evaluation of GCA by revealing the complex interrelation of clearly defined image findings with underlying vascular immunopathology and altered arterial tissue-specific miRNA profiles.

Temporal artery biopsy: A technical guide and review of its importance and indications

Temporal artery biopsy (TAB) is a surgical procedure that enables the histological diagnosis of giant cell arteritis (GCA). Performing a TAB requires expertise and a precise approach. Nevertheless, available data supports the value of tissue diagnosis in managing GCA. The current therapeutic recommendation for GCA is long-term glucocorticoid therapy, with an increasing emphasis on the addition of immunosuppressants/biotherapies. Though effective, immunosuppressants and other such biotherapies may put the patient at more risk. Optimizing the diagnosis through tissue evaluation is therefore important in weighing the risks and benefits of initiating therapeutic intervention. We evaluate the evidence supporting the importance of TAB and its indications. We also describe what technical approaches should be used to maximize sensitivity and to avoid possible complications during the procedure.

[Giant cell arteritis diagnosed by a temporal artery biopsy without abnormal imaging and physical findings in an elderly patient presenting with fever]

Giant cell arteritis (GCA) is considered in the differential diagnosis of fever of unknown origin in the elderly. We describe the case of an 83-year-old man with GCA diagnosed by temporal artery biopsy (TBA), who did not exhibit abnormal physical and imaging findings. The patient had fever and elevated C-reactive protein (CRP), which had persisted for two months. He was examined and treated with antibiotics and antipyretic analgesics in a local clinic, but they had little effect. He was referred to us. He showed no abnormal physical findings. Image examinations, including ultrasonography, CT, MRI, and PET-CT, showed no abnormal findings. We performed TBA. The histological examination of the artery showed inflammatory cell invasion and rupture of the internal elastic membrane, indicating GCA. We initiated oral corticosteroid treatment. The patient's fever quickly disappeared and his CRP level returned to normal. TBA has been the gold standard for the diagnosis of GCA. However, TBA is an invasive procedure and the sensitivity depends on the operator's skill level. Recently, imaging examinations have frequently been used for the diagnosis of GCA. The sensitivity of imaging examinations is similar to that of TBA. However, our case did not show any abnormal imaging findings and was only diagnosed by TBA. This case suggested that TBA remains a useful examination for elderly patients with fever that persists for a long time.

Effect of Temporal Artery Biopsy Length and Laterality on Diagnostic Yield

BACKGROUND

Giant cell arteritis (GCA) is the most common vasculitis in adults and is associated with significant morbidity and mortality. Temporal artery biopsy (TAB) remains the gold standard for diagnosis in the United States; however, practices vary in the length of artery obtained and whether bilateral simultaneous biopsies are obtained.

METHODS

Retrospective chart review of all TABs performed at the Johns Hopkins Wilmer Eye Institute between July 1, 2007, and September 30, 2017.

RESULTS

Five hundred eighty-six patients underwent TAB to evaluate for GCA. Of 404 unilateral biopsies, 68 (16.8%) were positive. Of 182 patients with bilateral biopsies, 25 (13.7%) had biopsies that were positive and 5 patients (2.7%) had biopsies that were discordant, meaning only 1 side was positive. There was no significant difference in the average postfixation length of positive and negative TAB specimens (positive mean length 1.38 ± 0.61 cm, negative mean length 1.39 ± 0.62 cm, P = 0.9).

CONCLUSIONS

There is no significant association between greater length of biopsy and a positive TAB result in our data. Although the rate of positive results was not higher in the bilateral group compared with the unilateral group, 2.7% of bilateral biopsies were discordant, similar to previously published rates. Overall, this suggests that initial bilateral biopsy may increase diagnostic yield, albeit by a small amount.

Validity of high resolution magnetic resonance imaging in detecting giant cell arteritis: a meta-analysis

OBJECTIVES

This study was designed to evaluate the performance of high-resolution magnetic resonance imaging (HR-MRI) in detecting giant cell arteritis (GCA), evaluate superficial extracranial artery and other MRI abnormalities, and compare three-dimensional (3D) and two-dimensional (2D) techniques.

METHODS

PubMed, Web of Science, and Cochrane Library were screened up to March 7, 2021, and further selection was performed according to the eligibility criteria. Quality Assessment of Diagnostic Accuracy Studies-2 was used for quality assessment, and heterogeneity assessment and statistical calculations were also performed.

RESULTS

In total, 1851 records were retrieved from online databases, and 15 studies were finally included. Regarding the performance of HR-MRI, the superficial extracranial artery had 75% sensitivity and 89% specificity, respectively, with an area under the receiver operating characteristic curve (AUC) of 0.91. Positive and negative post-test possibilities were 86% and 20%, respectively, with clinical diagnosis as reference. When referenced with temporal artery biopsy, the sensitivity was 91%, specificity was 78%, AUC was 0.92, and positive and negative post-test possibilities were 78% and 10%, respectively. 3D HR-MRI and 2D HR-MRI had 70% and 72% sensitivity, respectively, and 91% and 84% specificity, respectively.

CONCLUSIONS

HR-MRI is a valuable imaging modality for GCA diagnosis. It provided high accuracy in the diagnosis of GCA and played a potential role in identifying GCA-related ischemic optic neuropathy. 3D HR-MRI had better specificity than 2D HR-MRI.

KEY POINTS

HR-MRI helps clinicians to diagnose GCA. Superficial extracranial arteries and other MRI abnormalities can be assessed with HR-MRI. HR-MRI can help in assessing GCA-related optic neuropathy.

Colour Doppler ultrasound and the giant cell arteritis probability score for the diagnosis of giant cell arteritis: a Canadian single-centre experience

Objectives

The aim was to compare the accuracy of colour Doppler ultrasonography (CDUS) and temporal artery biopsy (TAB) to establish the final diagnosis of GCA and to determine how the GCA probability score (GCAPS) performs as a risk stratification tool.

Methods

Descriptive statistics were performed on a retrospective cohort of patients referred to our vasculitis referral centre between 1 July 2017 and 1 October 2020 for suspected GCA. CDUS, TAB, centre-specific TAB (vasculitis centre vs referring hospitals) and GCAPS were compared against the final diagnosis of GCA as determined by a GCA expert; CDUS was also compared with TAB results.

Results

Data from 198 patients were included: 60 patients with GCA and 138 patients without GCA. Sixty-two patients had a TAB. Using the final diagnosis by a GCA expert as a reference, the sensitivity, specificity, positive predictive value and negative predictive value were 93.3%, 98.5%, 96.6% and 97.1% for CDUS and 69.2%, 100%, 100% and 81.8% for TAB, respectively. The false-negative rate was 6.7% for CDUS and 30.8% for TAB. False-negative TAB mostly occurred when performed in referring hospitals (57.1%) as opposed to our vasculitis centre (21.1%). With a cut-off at 9.5 points, sensitivity for GCAPS was 98.3% and specificity 74.3%.

Conclusion

CDUS of the temporal and axillary arteries showed a high sensitivity and specificity and helped to diagnose GCA in patients with negative TAB. We validated that GCAPS is a useful clinical tool, with a score of <9.5 making the diagnosis of GCA improbable.

New insights into the pathogenesis of giant cell arteritis: are they relevant for precision medicine?

Giant cell arteritis is a primary granulomatous vasculitis characterised by a strict tissue tropism for large and medium-size vessels, occurring in people older than 50 years. Although considerable progress in understanding some of the pathophysiological mechanisms involved in the pathogenesis of giant cell arteritis has been made in the past 10 years, specific triggers of disease and mechanisms of chronic damage have not yet been identified. The definition of a specific pro-inflammatory hierarchy between the multiple cell types and the different cytokines or chemokines involved in the inflammatory process are still unexplored areas of study. The overall goal of precision medicine is to identify the best possible therapeutic approach for an individual or group of individuals with a given disease. The fundamental prerequisite of this approach is the identification, at baseline, of clinical and imaging findings and of molecular biomarkers that allow a precise stratification of patients and an adequate prediction of the therapeutic response. In this regard, the possibility of obtaining temporal artery biopsies for diagnostic purposes offers incredible exploratory possibilities to define different disease pathotypes potentially susceptible to different therapeutic interventions. In this Series paper, we will describe the most recent evidence relating to the pathogenesis of giant cell arteritis, trying to define, if possible, a new pathogenetic-centred approach to patients with giant cell arteritis.

Ultrasound Technologies and the Diagnosis of Giant Cell Arteritis

Giant cell arteritis (GCA) is a primary autoimmune vasculitis that specifically affects medium-sized extracranial arteries, like superficial temporal arteries (TAs). The most important data to be considered for the ultrasound (US) diagnosis of temporal arteritis are stenosis, acute occlusions and “dark halo” sign, which represent the edema of the vascular wall. The vessel wall thickening of large vessels in GCA can be recognized by the US, which has high sensitivity and is facile to use. Ocular complications of GCA are common and consist especially of anterior arterial ischemic optic neuropathies or central retinal artery occlusion with sudden, painless, and sharp loss of vision in the affected eye. Color Doppler imaging of the orbital vessels (showing low-end diastolic velocities and a high resistance index) is essential to quickly differentiate the mechanism of ocular involvement (arteritic versus non-arteritic), since the characteristics of TAs on US do not correspond with ocular involvement on GCA. GCA should be cured immediately with systemic corticosteroids to avoid further visual loss of the eyes.

Introducing an ANP-led temporal artery biopsy service for patients with suspected giant cell arteritis

Giant cell arteritis (GCA) is an uncommon autoimmune inflammatory vasculopathy that can lead to the destruction and occlusion of various arteries that consequently can cause serious complications such as stroke or sight loss. It is seen as a medical emergency. The most commonly affected vessel in GCA is the temporal artery in the side of the head, hence the condition is sometimes also referred to as 'temporal arteritis'. This article discusses the introduction of an advanced nurse practitioner-led temporal artery biopsy service.

Dysregulated Expression of Arterial MicroRNAs and Their Target Gene Networks in Temporal Arteries of Treatment-Naïve Patients with Giant Cell Arteritis

In this study, we explored expression of microRNA (miR), miR-target genes and matrix remodelling molecules in temporal artery biopsies (TABs) from treatment-naïve patients with giant cell arteritis (GCA, n = 41) and integrated these analyses with clinical, laboratory, ultrasound and histological manifestations of GCA. NonGCA patients (n = 4) served as controls. GCA TABs exhibited deregulated expression of several miRs (miR-21-5p, -145-5p, -146a-5p, -146b-5p, -155-5p, 424-3p, -424-5p, -503-5p), putative miR-target genes (YAP1, PELI1, FGF2, VEGFA, KLF4) and matrix remodelling factors (MMP2, MMP9, TIMP1, TIPM2) with key roles in Toll-like receptor signaling, mechanotransduction and extracellular matrix biology. MiR-424-3p, -503-5p, KLF4, PELI1 and YAP1 were identified as new deregulated molecular factors in GCA TABs. Quantities of miR-146a-5p, YAP1, PELI1, FGF2, TIMP2 and MMP9 were particularly high in histologically positive GCA TABs with occluded temporal artery lumen. MiR-424-5p expression in TABs and the presence of facial or carotid arteritis on ultrasound were associated with vision disturbances in GCA patients. Correlative analysis of miR-mRNA quantities demonstrated a highly interrelated expression network of deregulated miRs and mRNAs in temporal arteries and identified KLF4 as a candidate target gene of deregulated miR-21-5p, -146a-5p and -155-5p network in GCA TABs. Meanwhile, arterial miR and mRNA expression did not correlate with constitutive symptoms and signs of GCA, elevated markers of systemic inflammation nor sonographic characteristics of GCA. Our study provides new insights into GCA pathophysiology and uncovers new candidate biomarkers of vision impairment in GCA.

Association Between Specimen Length and Number of Sections and Diagnostic Yield of Temporal Artery Biopsy for Giant Cell Arteritis

OBJECTIVE

To investigate the association between specimen length and number of sections evaluated and the diagnostic yield of temporal artery biopsy (TAB) for giant cell arteritis (GCA).

METHODS

A pathologist reviewed all TABs performed for suspected GCA between January 1991 and December 2012. The blocks of all the inadequate and negative biopsy specimens were recut, and further slides at deeper levels were stained with hematoxylin and eosin in order to avoid missing inflammatory changes.

RESULTS

In total, findings from 662 TABs were included in the study (71% female; mean age 73.2 years). A total of 427 TAB specimens (65%) were classified as negative, and 235 (35%) were classified as positive for GCA. Compared to those with negative TAB results, patients with positive TAB results were older and more frequently female. There was no difference in postfixation TAB specimen length between TAB specimens negative and positive for GCA (mean 6.5 mm versus 6.9 mm; P = 0.068). Cuts of additional biopsy sections revealed inflammation at deeper levels in 26 of 408 TAB specimens (6.4%) originally reported as uninflamed. The inflamed section was the second in 14 TAB specimens, the third in 9 specimens, and the fourth in 3 specimens. Piecewise logistic regression identified 5 mm as the TAB specimen length change point for diagnostic sensitivity. Compared to a TAB specimen length of <5 mm, the age- and sex-adjusted odds ratio for positive TAB results in samples ≥5 mm long was 1.5 (95% confidence interval 1.0-2.0), P = 0.032.

CONCLUSION

A postfixation TAB specimen length of at least 5 mm should be sufficient to make a histologic diagnosis of GCA. In order not to miss inflammatory changes, at least 3 further sections at deeper levels should be evaluated in all negative TAB specimens.

The Adequate Number of Histopathology Cross-sections of Temporal Artery Biopsy in Establishing the Diagnosis of Giant Cell Arteritis

Purpose

To determine the appropriate number of histopathological cross-sections that are required for a conclusive diagnosis of giant cell arteritis (GCA).

Methods

In this cross-sectional study, the number of sections per slide for paraffin-embedded blocks for 100 randomly selected cases where GCA was suspected and those for negative temporal artery biopsies (TABs) were compared with the number of cross-sections per specimen for eight positive-TABs. All aforementioned examinations were conducted at our center from 2012 to 2016. Then, negative-TABs were retrieved and re-evaluated using light microscopy considering the histopathological findings of GCA.

Results

Ninety-five paraffin blocks were retrieved. The original mean biopsy length was 15.39 ± 7.56 mm. Comparison of the mean number of cross-sections per specimen for both the positive- and negative-TABs (9.25 ± 3.37 and 9.53 ± 2.46) showed that 9.87 ± 2.77 [95% confidence intervals (CI)] cross-sections per specimen were sufficient for a precise GCA diagnosis. There was no statistically significant difference in the mean biopsy length (P = 0.142) among the eight positive-TABs. Similarly, no significant difference was observed in the number of cross-sections per specimen (P = 0.990) for positive-TABs compared to those for the negative-TABs. After the retrieval of negative-TABs, the mean number of total pre- and post-retrieval cross-sections per specimen was 17.66 ± 4.43. Among all retrieved specimens, only one case (0.01%) showed the histopathological features of healed arteritis.

Conclusion

Positive-TABs did not reveal more histological cross-sections than the negative ones and increasing the number of cross-sections did not enhance the accuracy of TAB.

Evaluation of Temporal Artery Duplex Ultrasound for Diagnosis of Temporal Arteritis

BACKGROUND

Temporal arteritis or giant cell arteritis is a form of systemic inflammatory vasculitis closely associated with polymyalgia rheumatica. It may have serious systemic, neurologic, and ophthalmic consequences as it may lead to impaired vision and blindness. Definitive diagnosis is made after histopathologic analysis of a superficial temporal artery (TA) biopsy, which requires a small surgical procedure often under local anesthesia. We investigated whether a noninvasive technique such as duplex ultrasound of the TA could replace histopathological analysis.

METHODS

Eighty-one patients referred to our department for TA biopsy were first screened with a duplex ultrasound for a surrounding halo and/or occlusion of the TA. Presence of visual disturbances and unilateral pain (headache and/or tongue/jaw claudication) was noted before TA biopsy. Pathological analysis was considered the gold standard. Correlation between duplex findings, symptoms, and pathology was determined by Spearman's Rho test. The predictive value of a halo and TA occlusion on duplex were determined by ROC curve analysis.

RESULTS

A halo or TA occlusion was found in 16.0% and 3.7% of patients, respectively. Unilateral pain was reported in 96% of cases while 82% complained of visual disturbances. Correlation coefficients for halo and occlusion were 0.471 and 0.404, respectively (P < 0.0001), suggesting a moderate correlation between duplex and biopsy. There was no significant correlation between visual impairment or pain and histologic findings. The ROC curve analysis showed a sensitivity of 53.3% and 20.0%, and specificity of 91.9% and 100% for presence of a halo and occlusion of the TA on duplex, respectively.

CONCLUSIONS

Arterial duplex is a moderately sensitive but highly specific test for exclusion of temporal arteritis. We observed a moderate correlation between these findings on duplex and histopathological analysis as a gold standard. Arterial duplex may serve as a valuable diagnostic addition to prevent unnecessary surgical procedures and can even substitute biopsy in patients where surgery is not an option.

Full-field optical coherence tomography for the diagnosis of giant cell arteritis

Histopathological examination of temporal artery biopsy (TAB) remains the gold standard for the diagnosis of giant cell arteritis (GCA) but is associated with essential limitations that emphasize the need for an upgraded pathological process. This study pioneered the use of full-field optical coherence tomography (FF-OCT) for rapid and automated on-site pathological diagnosis of GCA. Sixteen TABs (12 negative and 4 positive for GCA) were selected according to major histopathological criteria of GCA following hematoxylin-eosin-saffron-staining for subsequent acquisition with FF-OCT to compare structural modifications of the artery cell wall and thickness of each tunica. Gabor filtering of FF-OCT images was then used to compute TAB orientation maps and validate a potential automated analysis of TAB sections. FF-OCT allowed both qualitative and quantitative visualization of the main structures of the temporal artery wall, from the internal elastic lamina to the vasa vasorum and red blood cells, unveiling a significant correlation with conventional histology. FF-OCT imaging of GCA TABs revealed destruction of the media with distinct remodeling of the whole arterial wall into a denser reticular fibrous neo-intima, which is distinctive of GCA pathogenesis and accessible through automated Gabor filtering. Rapid on-site FF-OCT TAB acquisition makes it possible to identify some characteristic pathological lesions of GCA within a few minutes, paving the way for potential machine intelligence-based or even non-invasive diagnosis of GCA.

Distinct macrophage phenotypes skewed by local granulocyte macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF) are associated with tissue destruction and intimal hyperplasia in giant cell arteritis

Objective

To determine the presence and spatial distribution of different macrophage phenotypes, governed by granulocyte macrophage colony‐stimulating factor (GM‐CSF) and macrophage colony‐stimulating factor (M‐CSF) skewing signals, in giant cell arteritis (GCA) lesions.

Methods

Temporal artery biopsies (TABs, n = 11) from treatment‐naive GCA patients, aorta samples from GCA‐related aneurysms (n = 10) and atherosclerosis (n = 10) were stained by immunohistochemistry targeting selected macrophage phenotypic markers, cytokines, matrix metalloproteinases (MMPs) and growth factors. In vitro macrophage differentiation (n = 10) followed by flow cytometry, Luminex assay and ELISA were performed to assess whether GM‐CSF and M‐CSF are drivers of macrophage phenotypic heterogeneity.

Results

A distinct spatial distribution pattern of macrophage phenotypes in TABs was identified. CD206⁺/MMP‐9⁺ macrophages were located at the site of tissue destruction, whereas FRβ⁺ macrophages were located in the inner intima of arteries with high degrees of intimal hyperplasia. Notably, this pattern was also observed in macrophage‐rich areas in GCA aortas but not in atherosclerotic aortas. Flow cytometry showed that GM‐CSF treatment highly upregulated CD206 expression, while FRβ was expressed by M‐CSF‐skewed macrophages, only. Furthermore, localised expression of GM‐CSF and M‐CSF was detected, likely contributing to macrophage heterogeneity in the vascular wall.

Conclusions

Our data document a distinct spatial distribution pattern of CD206⁺/MMP‐9⁺ macrophages and FRβ⁺ macrophages in GCA linked to tissue destruction and intimal proliferation, respectively. We suggest that these distinct macrophage phenotypes are skewed by sequential GM‐CSF and M‐CSF signals. Our study adds to a better understanding of the development and functional role of macrophage phenotypes in the pathogenesis of GCA and opens opportunities for the design of macrophage‐targeted therapies.

The role of vascular ultrasound in managing giant cell arteritis in ophthalmology

Giant cell arteritis is the most common systemic vasculitis in the elderly and is a potentially life-threatening ophthalmic emergency that can result in irreversible blindness. Blindness is most commonly associated with acute onset, irreversible arteritic ischemic optic neuropathy. Without treatment, second eye involvement may occur, resulting in bilateral blindness. Patients with established visual loss are treated with high-dose steroids and generally undergo a temporal artery biopsy to confirm their diagnosis. A significant number of patients are, however, referred for urgent ophthalmology assessment from concerns about "incipient" arteritic ischemic optic neuropathy. Before visual loss, patients may experience a range of ocular symptoms related to ischemia. This generally leads to treatment with high-dose systemic steroid and an urgent request for a temporal artery biopsy. Temporal artery biopsy is considered as the standard investigation for confirmatory diagnosis. It is generally arranged as soon as possible, although it is often not carried out for several days, and there may also be delays in histopathological reporting. It is often perceived that the patient is "safe" while on corticosteroids, in that they are being treated to avoid visual loss. What is not acknowledged, however, is that, if patients do not have giant cell arteritis and are being treated "just in case," they will often require a tapering of oral steroids over several weeks, exposing them to unnecessary and significant side effects. In the rheumatology setting, vascular ultrasound has emerged as a safe and reliable alternative to temporal artery biopsy as a point of care diagnostic tool in the management of giant cell arteritis. Given an experienced sonographer and optimal equipment, a rapid diagnosis can be established in a fast-track clinic setting, taking into consideration clinical assessment, scoring, and ultrasound findings. A huge advantage of ultrasound is that it provides immediate information that can be used to inform treatment decisions. We explore the evidence that supports the incorporation of vascular ultrasound into the ophthalmology repertoire to make a more efficient diagnosis that is cost-effective and associated with better patient outcomes, including a potential reduction in loss of sight and avoidance of unnecessary long-term steroid treatment by early exclusion of mimics.

[Eye involvement in large vesssel vasculitis (giant cell arteritis and Takayasu's arteritis)]

Giant cell arteritis (GCA) and Takayasu's arteritis are both forms of large vessel vasculitis and can be manifested in the eye. While GCA affects patients over the age of 50 years, patients with Takayasu's arteritis are between 15 and 30 years old. The diagnosis is based on a combination of anamnesis, imaging and systemic inflammatory reactions. The diagnosis can be confirmed by biopsy. Typical eye involvement of GCA are anterior ischemic optic neuropathy (AION) and central retinal artery occlusion, while Takayasu's arteritis involves hypertensive retinopathy and Takayasu's retinopathy (capillary dilatation, microaneurysms and arteriovenous anastomoses). The treatment consists of steroids in combination with classical immunosuppressants or biologics.

Varicella Zoster Virus in Giant Cell Arteritis: A Review of Current Medical Literature

In recent years, the search for the cause of giant cell arteritis (GCA) has led investigators to look to varicella zoster virus (VZV) as the answer. In some ways, the nature of VZV infection makes it an attractive explanation for the pathology observed in GCA. However, studies to date yield a level of inconsistency that still leaves uncertainty as to whether VZV directly causes GCA, and positive findings have not been successfully reproduced.

Clinical Translation of a Novel Photoacoustic Imaging System for Examining the Temporal Artery

The objective was to provide a clinical setup for photoacoustic imaging (PAI) of the temporal artery in humans and to describe the challenges encountered and methods of overcoming them. The temporal artery was examined in seven patients with suspect giant-cell arteritis (GCA), both in vivo and ex vivo, and the results were compared to that of histology. To adapt PAI to the human studies, the transducer was fixed to an adjustable arm to reduce motion artifacts, and a stepping motor was developed to enable 3-D scanning. Risks associated with the use of lasers, ultrasound, and electrical equipment were evaluated by measuring energy levels, and safety precautions were undertaken to prevent injury to the patients and staff. The PAI spectra obtained clearly delineated the artery wall, both in vivo and ex vivo, although the latter was of high quality due to the lack of artifacts. The results could be compared to that of histology. The involved energy levels were found to be below the limits given in regulatory standards. Eye protectors prevented irradiation of the patient's eyes, and visual function after the procedure was found not to be affected. The patients reported no discomfort during the investigations. PAI provides images of the temporal artery wall that may be used for the future diagnosis of GCA in humans. The technique could be further refined by addressing the specific problems of motion artifacts and interference from blood and other chromophores. This study paves the way for other clinical applications of PAI.

Description and Validation of Histological Patterns and Proposal of a Dynamic Model of Inflammatory Infiltration in Giant-cell Arteritis

The extent of inflammatory infiltrates in arteries from patients with giant-cell arteritis (GCA) have been described using different terms and definitions. Studies investigating the relationship between GCA histological features and clinical manifestations have produced controversial results. The aims of this study were to characterize and validate histological patterns in temporal artery biopsies (TABs) from GCA patients, to explore additional histological features, including the coexistence of different patterns, and also to investigate the relationship of the inflammatory patterns with clinical and laboratory features.We performed histological examination of TAB from patients with GCA consecutively diagnosed between 1992 and 2012. Patterns of inflammation were defined according to the extent and distribution of inflammatory infiltrates within the artery. Clinical and laboratory variables were recorded. Two external investigators underwent a focused, one-day training session and then independently scored 77 cases. Quadratic-weighted kappa was calculated.TAB from 285 patients (200 female/85 male) were evaluated. Four histological inflammatory patterns were distinguished: 1 - adventitial (n = 16); 2 - adventitial invasive: adventitial involvement with some extension to the muscular layer (n = 21); 3 - concentric bilayer: adventitial and intimal involvement with media layer preservation (n = 52); and 4 - panarteritic (n = 196). Skip lesions were observed in 10% and coexistence of various patterns in 43%. Raw agreement of each external scorer with the gold-standard was 82% and 77% (55% and 46% agreement expected from chance); kappa = 0.82 (95% confidence interval [CI] 0.70-0.95) and 0.79 (95% CI 0.68-0.91). Although abnormalities on temporal artery palpation and the presence of jaw claudication and scalp tenderness tended to occur more frequently in patients with arteries depicting more extensive inflammation, no statistically significant correlations were found between histological patterns and clinical features or laboratory findings.In conclusion, we have described and validated 4 histological patterns. The presence of different coexisting patterns likely reflects sequential steps in the progression of inflammation and injury. No clear relationship was found between these patterns and clinical or laboratory findings. However, several cranial manifestations tended to occur more often in patients with temporal arteries exhibiting panarteritic inflammation. This validated score system may be useful to standardize stratification of histological severity for immunopathology biomarker studies or correlation with imaging.

Giant cell arteritis: a closer look at its ophthalmological manifestations

Giant cell arteritis with ocular involvement is an ocular emergency. Arteritic anterior ischaemic optic neuropathy (AAION) is the most common ophthalmological manifestation associated with this disease. Visual loss is usually permanent with rare cases showing visual recovery. Visual improvement, if it occurs, is generally limited, and the visual field defects are persistent and severe. The main goal of AAION treatment is the preservation of vision in the fellow eye. In patients with neurophthalmological manifestations, high-dose corticosteroids should be initiated immediately and aggressively, and maintained thereafter. We present a case of AAION and severe vision loss where significant visual recovery was seen after treatment.

MicroRNA markers of inflammation and remodelling in temporal arteries from patients with giant cell arteritis

OBJECTIVES

There is increasing evidence that microRNAs (miRNAs) are deregulated in autoimmune and cardiovascular diseases. The present study aimed to identify if miRNAs are deregulated in giant cell arteritis (GCA), a vasculitis affecting large-sized and medium-sized arteries, and to determine if miRNA levels might allow to discriminate between patients with GCA and those without.

METHODS

58 patients who had temporal artery biopsy (TAB) for suspected GCA were included in the study and divided into three groups: patients with TAB-positive GCA showing a transmural inflammation (n=27), patients with TAB-negative GCA (n=8) and TAB-negative non-GCA patients with a final diagnosis different from GCA (n=23). To identify candidate miRNAs deregulated in GCA, we profiled the expression of 1209 miRNAs in inflamed TABs and normal TABs. Selected miRNAs were then validated by real-time PCRs and in situ hybridisation (ISH).

RESULTS

MiR-146b-5p, -146a, -155, -150, -21 and -299-5p were significantly more expressed in inflamed TABs from patients with GCA. miRNAs were mainly deregulated at the tissue level because peripheral blood mononuclear cells and polymorphonuclear cells from the three groups of patients and age-matched healthy controls had similar levels of miRNAs. ISH showed that miR-21 was mainly expressed by cells in the medial and intimal layers of inflamed TABs. Patients with TAB-negative GCA had a miRNA profile similar to TAB-negative non-GCA patients.

CONCLUSIONS

MiR-146b-5p, -146a, -21, -150, -155, -299-5p are overexpressed in the presence of inflammation in TABs from patients with GCA.

Histopathology of the Inner Ear in a Case With Recent Onset of Cogan’s Syndrome

The association of sensorineural hearing loss and vertigo with inflammatory eye disease, usually interstitial keratitis, has been called Cogan’s syndrome. The pathogenesis of Cogan’s syndrome is unknown, but it has been assumed to be an immune mediated disorder with vasculitis. The histopathology of the inner ear in Cogan’s syndrome has been described in 6 case reports. Although common pathologic findings in these reports include degeneration of the auditory and vestibular neuroepithelium, endolymphatic hydrops, fibrosis, and new bone formation, direct pathologic evidence of a vasculitis has not been published. A possible reason for this failure to identify vasculitis was a substantial delay (range, 4-40 years) between the onset of symptoms and examination of the otopathology. In the current case report, the patient had both auditory and vestibular symptoms and interstitial keratitis with a time delay of only 2 to 4 weeks between symptoms and death. Evidence of a vasculitis as a possible underlying etiology included H&E histopathology and anti-CD45 immunostaining of vessels both in the auditory and vestibular systems, supporting the hypothesis of a vasculitis as a mechanism in this disorder.

Diagnostic value of color Doppler ultrasonography of temporal arteries and large vessels in giant cell arteritis: a consecutive case series

OBJECTIVE

Color Doppler ultrasonography (CDUS) can detect inflammation in the vessel wall. No studies have evaluated the examination of the common carotid artery by CDUS in the diagnostics of giant cell arteritis (GCA). Our aim was to evaluate the combination of CDUS examination of the temporal, axillary, and common carotid arteries in the diagnosis of GCA.

METHODS

Patients ages ≥50 years who were referred to our department between April 2010 and October 2012 and suspected to have GCA were consecutively examined. A positive clinical evaluation for GCA 6 months after the first evaluation by 3 rheumatologists was considered as the gold diagnostic standard. All patients underwent CDUS of the temporal, axillary, and common carotid arteries. A biopsy of the temporal artery was performed for most patients.

RESULTS

A total of 88 patients were assessed. Forty-six patients were diagnosed to have GCA by the defined gold standard. Forty-eight patients had a positive CDUS of the temporal artery. Forty-six patients diagnosed with GCA had a positive CDUS of the temporal, common carotid, and axillary arteries (100% sensitivity) and 4 patients had a positive CDUS without having GCA (91% specificity). Among the 39 GCA patients that underwent a biopsy, vasculitis was observed in 26 patients (66%), yielding a sensitivity of 67% and a specificity of 95%.

CONCLUSION

CDUS of the common carotid, axillary, and temporal arteries had an excellent sensitivity and high specificity to diagnose GCA. CDUS has the potential to replace biopsy in ordinary clinical care without compromising on sensitivity and specificity.

Temporal artery biopsy size does not matter

This study aimed to clarify whether positive temporal artery biopsies had a greater sample length than negative biopsies in temporal arteritis. It has been suggested that biopsy length should be at least 1 cm to improve diagnostic accuracy. A retrospective review of 149 patients who had 151 temporal artery biopsies was conducted. Twenty biopsies were positive (13.3%), 124 negative (82.1%) and seven samples were insufficient (4.6%). There was no clinically significant difference in the mean biopsy size between positive (0.7 cm) and negative samples (0.65 cm) ( t-test: p = .43 NS). Ninety-four patients fulfilled all three ACR criteria prior to biopsy (62.3%) and four patients (2.6%) changed ACR score from 2 to 3 after biopsy. Treatment should not be delayed in anticipation of the biopsy or withheld in the case of a negative biopsy if the patient’s symptoms improve.

The diagnosis and treatment of giant cell arteritis

BACKGROUND

Giant cell arteritis (GCA) is the most common systemic vasculitis in persons aged 50 and above (incidence, 3.5 per 100,000 per year). It affects cranial arteries, the aorta, and arteries elsewhere in the body, e.g., in the limbs.

METHODS

We selectively review the pertinent literature, including guidelines and recommendations from Germany and abroad.

RESULTS

The typical symptoms of new-onset GCA are bitemporal headaches, jaw claudiacation, scalp tenderness, visual disturbances, systemic symptoms such as fever and weight loss, and polymyalgia. The diagnostic assessment comprises laboratory testing (erythrocyte sedimentation rate, C-reactive protein), imaging studies (duplex sonography, high-resolution magnetic resonance imaging, positron-emission tomography), and temporal artery biopsy. The standard treatment is with corticosteroids (adverse effects: diabetes mellitus, osteoporosis, cataract, arterial hypertension). A meta-analysis of three randomized controlled trials led to a recommendation for treatment with methotrexate to lower the recurrence rate and spare steroids. Patients for whom methotrexate is contraindicated or who cannot tolerate the drug can be treated with azathioprine instead.

CONCLUSION

Giant cell arteritis, if untreated, progresses to involve the aorta and its collateral branches, leading to various complications. Late diagnosis and treatment can have serious consequences, including irreversible loss of visual function.

[Giant cell arteritis: etiological knowledge and diagnostic challenge for pathologists]

Giant cell arteritis is a potentially systemic disease of medium-sized and large caliber arteries, showing a preferential manifestation in the extracranial branches of the carotid artery. The diagnosis is oriented to clinical and histomorphological criteria which will be critically reviewed. Particular emphasis is placed on the differentiation from normal aging processes and from healing stages under steroid therapy. In addition, the advances in our understanding of the disease pathomechanism during the last 10 years will be briefly presented as the basis for the hitherto empiric steroid treatment.

The role of temporal artery biopsies in giant cell arteritis

A knowledge of the disease process of giant cell arteritis and its diagnosis can help a surgeon to decide which patients will benefit from a biopsy being performed and identify where a biopsy would be of no value in their management. This article discusses the issues involved.

Diagnosis and management of giant cell arteritis: a review

PURPOSE OF REVIEW

This article aims to provide a review of giant cell arteritis (GCA) clinical features, differential diagnosis, treatment options, and recent literature.

RECENT FINDINGS

GCA, first described by Horton et al., is a systemic immune-mediated vasculitis affecting medium-sized and large-sized arteries. Characteristic findings include headache, jaw claudication, visual loss, and constitutional symptoms (malaise, fever, weight loss, loss of appetite). Localized GCA symptoms are the end-result of vascular insufficiency and tissue ischemia. Temporal artery biopsy (TAB) remains the gold standard for diagnosis. Additional diagnostic tests include blood tests (erythrocyte sedimentation rate, ESR; C-reactive protein, CRP; platelets) and imaging modalities (ultrasound of the arteries; fluorescein angiography, FA; MRI; and positron emission tomography, PET). The mainstay of management includes high-dose corticosteroids, and additional cytotoxic drugs, antitumor necrosis factor monoclonal antibody, and antiplatelet aggregation therapy may be used. The goal of treatment is to prevent ischemic damage and halt progression of visual loss in the affected eye and prevent involvement of the fellow eye.

SUMMARY

Further research is warranted concerning the immunogenetics of GCA. Further treatment trials are also needed to develop more specific and sensitive diagnostic tests and new corticosteroid-sparing treatment modalities.