Rate of Discordant Findings in Bilateral Temporal Artery Biopsy to Diagnose Giant Cell Arteritis

Temporal artery biopsy in giant cell arteritis: clinical perspectives and histological patterns

Although its role has been debated, temporal artery biopsy (TAB) remains the gold standard for the diagnosis of cranial giant cell arteritis (GCA). The specificity of TAB is excellent and the sensitivity, albeit lower, is comparable with other diagnostic modalities used for the diagnosis of GCA. This outpatient procedure has a low rate of complications and is well integrated in the majority of healthcare systems. The length of the specimen, the number of the examined sections and the prolonged use of glucocorticoids before the biopsy may affect the outcome of the TAB as diagnostic tool. The typical histological findings in GCA are often characterized by granulomatous inflammation with infiltration of mononuclear cells with or without the presence of giant cell, varying degrees of external and internal elastic lamina damage and intimal thickening. Overlooking signs of inflammation in the adventitia and in connective tissue surrounding the temporal artery may lead to false negative results. The distinction between healed arteritis and age-related atherosclerosis may be challenging.

Age-related histopathological findings in temporal arteries

AIMS

Giant cell arteritis (GCA) is a systemic vasculitis affecting medium and large arteries in patients aged over 50 years. Involvement of temporal arteries (TA) can lead to complications such as blindness and stroke. While the diagnostic gold standard is temporal artery biopsy (TAB), comorbidities and age-related changes can make interpretation of such specimens difficult. This study aims to establish a baseline of TA changes in subjects without GCA to facilitate the interpretation of TAB.

METHODS AND RESULTS

Bilateral TA specimens were collected from 100 consecutive eligible postmortem examinations. Subjects were divided into four age groups and specimens semiquantitatively evaluated for eccentric intimal fibroplasia, disruption and calcification of the internal elastic lamina (IEL), medial attenuation and degree of lymphocytic inflammation of the peri-adventitia, adventitia, media and intima. The individual scores of intimal fibroplasia, IEL disruption and medial attenuation were added to yield a 'combined score (CS)'. Seventy-eight 78 decedents were included in the final analysis following exclusion of 22 individuals for either lack of clinical information or inability to collect TA tissue. A total of 128 temporal artery specimens (50 bilateral from individual decedents, 28 unilateral) were available for examination. Intimal proliferation, IEL loss, IEL calcification and CS increased with age in a statistically significant fashion. Comparison of the oldest age group with the others showed statistically significant differences, although this was not uniformly preserved in comparison between the three youngest groups.

CONCLUSION

Senescent arterial changes and healed GCA exhibit histological similarity and such changes increase proportionally with age. The CS demonstrates significant association with age overall and represents a potential avenue for development to 'normalise' TA biopsies from older individuals.

Consensus statement on the processing, interpretation and reporting of temporal artery biopsy for arteritis

Giant cell arteritis (GCA) is the most common systemic vasculitis in adults in Europe and North America, typically involving the extra-cranial branches of the carotid arteries and the thoracic aorta. Despite advances in noninvasive imaging, temporal artery biopsy (TAB) remains the gold standard for establishing a GCA diagnosis. The processing of TAB depends largely on individual institutional protocol, and the interpretation and reporting practices vary among pathologists. To address this lack of uniformity, the Society for Cardiovascular Pathology formed a committee tasked with establishing consensus guidelines for the processing, interpretation, and reporting of TAB specimens, based on the existing literature. This consensus statement includes a discussion of the differential diagnoses including other forms of arteritis and noninflammatory changes of the temporal artery.

The Utility of the Bilateral Temporal Artery Biopsy for Diagnosis of Giant Cell Arteritis

OBJECTIVE

A surgical temporal artery biopsy (TAB) is the gold standard for diagnosis of giant cell arteritis (GCA). The necessity of performing a bilateral biopsy remains under debate. The primary objective of this study was to assess the rate of discordance between pathology results in patients who underwent bilateral temporal artery biopsy for suspected GCA.

METHODS

We performed a retrospective review of patients who underwent bilateral temporal artery biopsy for diagnosis of GCA between 2011 and 2020. The primary endpoint was the rate of discordance between specimens for patients with pathology positive GCA. Secondary endpoints included assessments of the sensitivity of pre-operative temporal artery duplex and the effects of specimen length and specialty of referring provider on the diagnostic yield of the biopsy.

RESULTS

During the study period, 310 patients underwent bilateral temporal artery biopsy for diagnosis of giant cell arteritis. These patients were primarily female (73.9%), elderly (mean age 70.8 years), and Caucasian (95.8%). Pre-operative symptoms for patients were typically bilateral (59%) and included headache (81%), vision changes (45.2%), and temporal tenderness (32.6%). Most patients (85.2%) were on pre-operative steroid therapy at the time of surgical biopsy with a mean pre-operative duration of steroid therapy of 15.1 days. Overall, 91 patients (29.4%) had a positive pathologic diagnosis after bilateral temporal artery biopsy. Of these patients, 11 had a positive pathology result in only a single specimen, resulting in a discordance rate of 12.1%. Pre-operative temporal artery duplex demonstrated low sensitivity (27.3%) for identifying patients with pathologic positive disease. There were no significant differences between the pathology positive and negative patients in terms of mean surgical specimen length (1.67 vs 1.64 cm; p = 0.67) or specialty of referring provider (p = 0.73).

CONCLUSIONS

At our institution, we observed a 12.1% discordance rate between pathology results in patients who underwent bilateral temporal artery biopsy for diagnosis of GCA. A pre-operative temporal artery duplex provided little value in identifying patients with biopsy-proven GCA.

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.

Discordance Rate Among Bilateral Simultaneous and Sequential Temporal Artery Biopsies in Giant Cell Arteritis: Role of Frozen Sectioning Based on the Mayo Clinic Experience

Importance

Frozen section temporal artery biopsy (TAB) may prevent a contralateral biopsy from being performed.

Objective

To evaluate the sensitivity and specificity of TAB frozen vs permanent section pathology results for giant cell arteritis (GCA) and determine the discordance rate of bilateral TABs.

Design, Setting, and Participants

In this retrospective cohort study, medical records were reviewed from 795 patients 40 years or older who underwent TAB from January 1, 2010, to December 1, 2018, treated at a single tertiary care center with the ability to perform both frozen and permanent histologic sections. Data were analyzed from January 2019 to December 2020.

Main Outcomes and Measures

Sensitivity and specificity of frozen section TAB for detecting GCA, and discordance rates of bilateral permanent section TAB.

Results

Of the 795 included participants, 329 (41.4%) were male, and the mean (SD) age was 72 (10) years. From the 795 patients with 1162 TABs, 119 patients (15.0%) and 138 TABs had positive findings on permanent section. Of these 119 patients, 103 (86.6%) also had positive results on the frozen section, with 4 false-positives (0.6%) and 20 false-negatives (16.8%). Frozen section had a specificity of 99.4% (95% CI, 98.5-99.8), sensitivity of 83.2% (95% CI, 75.2-89.4), positive predictive value of 96.1% (95% CI, 90.4-98.9), negative predictive value of 96.6% (95% CI, 94.9-97.8), positive likelihood ratio of 140.6 (95% CI, 72.7-374.8), and a negative likelihood ratio of 0.17 (95% CI, 0.11-0.25). Simultaneous bilateral TABs were performed in 60 patients (7.5%) with a 5% discordance rate on permanent section. In comparison, bilateral frozen section-guided sequential TABs were performed in 307 patients (38.6%) with 5.5% discordance based on permanent section. In multivariate models, there was a greater odds of positive findings with age (odds ratio [OR], 1.04; 95% CI, 1.01-1.07; P = .008), vision loss (OR, 2.72; 95% CI, 1.25-5.75; P = .01), diplopia (OR, 3.33; 95% CI, 1.00-10.29; P = .04), headache (OR, 2.32; 95% CI, 1.25-4.53; P = .01), weight loss (OR, 2.37; 95% CI, 1.26-4.43; P = .007), and anorexia (OR, 5.65; 95% CI, 2.70-11.89; P < .001).

Conclusions and Relevance

These results support the hypothesis that negative findings from frozen sections should not be solely relied on to refute the diagnosis of GCA, whereas positive findings from frozen sections can be reliably used to defer a contralateral biopsy pending the permanent section results.

Temporal artery biopsy for suspected giant cell arteritis: a retrospective analysis

Temporal artery biopsy (TAB) is one of the diagnostic criteria of giant cell arteritis (GCA) according to 1990 ACR criteria and remains a tool for diagnosis. Although clinicians perform TAB with an intent to confirm suspected GCA, some biopsies result in negative and some lead to non-GCA diagnoses. We aim to review the diagnoses after TAB biopsy performed for suspected GCA and also wanted to evaluate the diagnostic changes and concomitant diseases that develop over time. The patients who had undergone TAB for suspected GCA were identified using the record entry code for TAB. Patients meeting the classification criteria for GCA were designated as the GCA group and not meeting criteria were designated as a non-GCA group. Other classification criteria were implemented for the non-GCA group diseases. A total of 51 patients (Female: 62.7%, median age: 72.1 ± 7.4 years) who had undergone TAB for suspected GCA were evaluated. TAB was positive in 23 (69.6%) of the 33 patients who met the GCA classification criteria. No significant difference was found between TAB-positive and TAB-negative GCA patients in terms of clinical and laboratory parameters. In the non-GCA group, 12 patients had isolated polymyalgia rheumatica (PMR), and the diagnoses of the remaining six patients were as follows: four large vessel vasculitis (LVV) not satisfying GCA diagnostic criteria, one chronic myelomonocytic leukemia (CMML), and one amyloidosis. TAB was negative in all patients with isolated PMR. TAB showed primary amyloidosis in one patient. Out of 33 GCA patients, 21 had "isolated" GCA, four had GCA + Rheumatoid arthritis (RA), seven had GCA + PMR, and one had GCA + polymyositis. RA was diagnosed antecedent to GCA in two patients, and after GCA in the other two patients. One of the patients had developed GCA 20 years after polymyositis had been diagnosed. TAB was found to be positive in two-thirds of patients with suspected GCA. Late-onset RA and rarely other inflammatory rheumatic diseases may develop in the course of GCA.

Steroid Use is Associated with Clinically Irrelevant Biopsies in Patients with Suspected Giant Cell Arteritis

Temporal artery biopsy (TAB) is the diagnostic gold standard for giant cell arteritis (GCA). GCA is treated by high-dose corticosteroids. In cases of high clinical suspicion, steroids may be administrated despite negative TAB, making TAB clinically irrelevant. We assessed the role of TAB in clinical decision-making in patients with suspected GCA and to identify factors associated with clinically irrelevant TAB. Charts of patients who underwent TAB from 2005 to 2010 were reviewed for clinical parameters potentially associated with GCA and clinically irrelevant TAB. We studied 143 patients with 99 negative (69%), 34 positive (24%), and 10 undefined (7%) TABs. Eventually 26 patients (18% of the entire cohort and 26% of the patients with a negative TAB) received steroid treatment for GCA despite negative TAB. The start of steroid treatment before TAB was associated with clinically irrelevant TABs. If clinical suspicion of GCA is high, a TAB can be considered clinically irrelevant.

Impact of Temporal Artery Biopsy on Clinical Management of Suspected Giant Cell Arteritis

BACKGROUND

Temporal arteritis (TA) is a systemic inflammatory vasculitis of unclear etiology that affects medium-sized vessels. The gold standard for diagnosis has traditionally been histological, by temporal artery biopsy. Improved imaging modalities have been increasingly used to aid diagnosis and are recommended in the newest 2018 European (EULAR) guidelines.¹ We hypothesize that a negative TA biopsy result does not change management in patients for whom TA is strongly suspected and that duplex ultrasound can be successfully used as a screening tool.

METHODS

This is a retrospective review of patients who underwent TA biopsy between May 1, 2012 and June 1, 2017. We reviewed patient's demographics, comorbidities, symptoms, histology, and treatment. We also present a small series of patients for whom ultrasound of the bilateral temporal arteries was performed. Radiology and pathology reports on these 7 patients were reviewed.

RESULTS

A total of 264 patients underwent temporal artery biopsies over the study period. Histology was positive in 21 (8.0%) and negative in 243 (92%) patients. In 74 (41%) patients with negative biopsies on steroids preoperatively, steroids were continued despite negative biopsy result. In prospective series, 7 patients underwent duplex ultrasound evaluation before scheduling for biopsy. Biopsy followed ultrasound in 4 cases, and in all 4 cases, histology was congruent with ultrasound findings.

CONCLUSIONS

The yield of temporal artery biopsy is low, and a negative biopsy alone often does not lead to termination of steroid therapy. Ultrasound may present a viable diagnostic tool to reduce the number of unnecessary temporal artery biopsies performed.

Diagnosis of giant cell arteritis

GCA is the most common form of primary systemic vasculitis affecting older people. It is considered a clinical emergency because it can lead to irreversible blindness in around 20% of untreated cases. High doses of glucocorticoids should be initiated promptly to prevent disease-related complications; however, glucocorticoids therapy usually results in significant toxicity. Therefore, correct diagnosis is crucial. For many years, temporal artery biopsy has been considered the diagnostic ‘gold standard’ for GCA, but it has many limitations (including low sensitivity). US has proven to be effective for diagnosing GCA and can reliably replace temporal artery biopsy in particular clinical settings. In cases of suspected GCA with large-vessel involvement, other imaging modalities can be used for diagnosis (e.g. CT and PET). Here we review the current evidence for each diagnostic modality and propose an algorithm to diagnose cranial-GCA in a setting with rapid access to high quality US.

Temporal Artery Biopsy for Diagnosing Giant Cell Arteritis: A Ten-year Review

Purpose

To assess the use of temporal artery biopsy (TAB) in diagnosing giant cell arteritis (GCA) and to evaluate patients' clinical and laboratory characteristics.

Methods

We conducted a retrospective chart review of patients with suspected GCA who underwent TAB and had complete workup in a tertiary center in Iran between 2008 and 2017. The 2016 American College of Rheumatology (ACR) revised criteria for early diagnosis of GCA were used for each patient for inclusion in this study.

Results

The mean age of the 114 patients in this study was 65.54 ± 10.17 years. The mean overall score according to the 2016 ACR revised criteria was 4.17 ± 1.39, with 5.82 ± 1.28 for positive biopsies and 3.88 ± 1.19 for negative biopsies (p <0.001). Seventeen patients (14.9%) had a positive biopsy. Although the mean post-fixation specimen length in the biopsy-positive group (18.35 ± 6.9 mm) was longer than that in the biopsy-negative group (15.62 ± 8.4 mm), the difference was not statistically significant (P = 0.21). There was no statistically significant difference between the groups in terms of sex, serum hemoglobin, platelet count, and erythrocyte sedimentation rate. There were statistically significant differences between the biopsy-negative and biopsy-positive groups with respect to patients' age and C-reactive protein level (P< 001 and P = 0.012, respectively).

Conclusion

The majority of TABs were negative. Reducing the number of redundant biopsies is necessary to decrease workload and use of medical services. We suggest that the diagnosis of GCA should be dependent on clinical suspicion.

Giant cell arteritis-related aortitis with positive or negative temporal artery biopsy: a French multicentre study

Objective: To compare the clinical presentation and outcome of giant cell arteritis (GCA)-related aortitis according to the results of temporal artery biopsy (TAB).Method: Patients with GCA-related aortitis diagnosed between 2000 and 2017, who underwent TAB, were retrospectively included from a French multicentre database. They all met at least three American College of Rheumatology criteria for the diagnosis of GCA. Aortitis was defined by aortic wall thickening > 2 mm on computed tomography scan and/or an aortic aneurysm, associated with an inflammatory syndrome. Patients were divided into two groups [positive and negative TAB (TAB+, TAB-)], which were compared regarding aortic imaging characteristics and aortic events, at aortitis diagnosis and during follow-up.Results: We included 56 patients with TAB+ (70%) and 24 with TAB- (30%). At aortitis diagnosis, patients with TAB- were significantly younger than those with TAB+ (67.7 ± 9 vs 72.3 ± 7 years, p = 0.022). Initial clinical signs of GCA, inflammatory parameters, and glucocorticoid therapy were similar in both groups. Coronary artery disease and/or lower limb peripheral arterial disease was more frequent in TAB- patients (25% vs 5.3%, p = 0.018). Aortic wall thickness and type of aortic involvement were not significantly different between groups. Diffuse arterial involvement from the aortic arch was more frequent in TAB- patients (29.1 vs 8.9%, p = 0.03). There were no differences between the groups regarding overall, aneurism-free, relapse-free, and aortic event-free survival.Conclusion: Among patients with GCA-related aortitis, those with TAB- are characterized by younger age and increased frequency of diffuse arterial involvement from the aortic arch compared to those with TAB+, without significant differences in terms of prognosis.

Giant cell arteritis: is the clinical spectrum of the disease changing?

BACKGROUND

Giant cell arteritis is a vasculitis of large and middle-sized arteries that affects patients aged over 50 years. It can show a typical clinical picture consisting of cranial manifestations but sometimes nonspecific symptoms and large-vessel involvement prevail. Prompt diagnosis and treatment is essential to avoid irreversible damage.

DISCUSSION

There has been an increasing knowledge on the occurrence of the disease without the typical cranial symptoms and its close relationship and overlap with polymyalgia rheumatica, and this may contribute to reduce the number of underdiagnosed patients. Although temporal artery biopsy is still the gold-standard and temporal artery ultrasonography is being widely used, newer imaging techniques (FDG-PET/TAC, MRI, CT) can be of valuable help to identify giant cell arteritis, in particular in those cases with a predominance of extracranial large-vessel manifestations.

CONCLUSIONS

Giant cell arteritis is a more heterogeneous condition than previously thought. Awareness of all the potential clinical manifestations and judicious use of diagnostic tests may be an aid to avoid delayed detection and consequently ominous complications.

Neural network and logistic regression diagnostic prediction models for giant cell arteritis: development and validation

PURPOSE

To develop and validate neural network (NN) vs logistic regression (LR) diagnostic prediction models in patients with suspected giant cell arteritis (GCA). Design: Multicenter retrospective chart review.

METHODS

An audit of consecutive patients undergoing temporal artery biopsy (TABx) for suspected GCA was conducted at 14 international medical centers. The outcome variable was biopsy-proven GCA. The predictor variables were age, gender, headache, clinical temporal artery abnormality, jaw claudication, vision loss, diplopia, erythrocyte sedimentation rate, C-reactive protein, and platelet level. The data were divided into three groups to train, validate, and test the models. The NN model with the lowest false-negative rate was chosen. Internal and external validations were performed.

RESULTS

Of 1,833 patients who underwent TABx, there was complete information on 1,201 patients, 300 (25%) of whom had a positive TABx. On multivariable LR age, platelets, jaw claudication, vision loss, log C-reactive protein, log erythrocyte sedimentation rate, headache, and clinical temporal artery abnormality were statistically significant predictors of a positive TABx (P≤0.05). The area under the receiver operating characteristic curve/Hosmer-Lemeshow P for LR was 0.867 (95% CI, 0.794, 0.917)/0.119 vs NN 0.860 (95% CI, 0.786, 0.911)/0.805, with no statistically significant difference of the area under the curves (P=0.316). The misclassification rate/false-negative rate of LR was 20.6%/47.5% vs 18.1%/30.5% for NN. Missing data analysis did not change the results.

CONCLUSION

Statistical models can aid in the triage of patients with suspected GCA. Misclassification remains a concern, but cutoff values for 95% and 99% sensitivities are provided (https://goo.gl/THCnuU).

Diagnosis and differential diagnosis of large-vessel vasculitides

There are no universally accepted diagnostic criteria for large-vessel vasculitides (LVV), including giant cell arteritis (GCA) and Takayasu arteritis (TAK). Currently, available classification criteria cannot be used for the diagnosis of GCA and TAK. Early diagnosis of these two diseases is quite challenging in clinical practice and may be accomplished only by combining the patient symptoms, physical examination findings, blood test results, imaging findings, and biopsy results, if available. Awareness of red flags which lead the clinician to investigate TAK in a young patient with persistent systemic inflammation is helpful for the early diagnosis. It should be noted that clinical presentation may be highly variable in a subgroup of GCA patients with predominant large-vessel involvement (LVI) and without prominent cranial symptoms. Imaging modalities are especially helpful for the diagnosis of this subgroup. Differential diagnosis between older patients with TAK and this subgroup of GCA patients presenting with LVI may be difficult. Various pathologies may mimic LVV either by causing systemic inflammation and constitutional symptoms, or by causing lumen narrowing with or without aneurysm formation in the aorta and its branches. Differential diagnosis of aortitis is crucial. Infectious aortitis including mycotic aneurysms due to septicemia or endocarditis, as well as causes such as syphilis and mycobacterial infections should always be excluded. On the other hand, the presence of non-infectious aortitis is not unique for TAK and GCA. It should be noted that aortitis, other large-vessel involvement or both, may occasionally be seen in various other autoimmune pathologies including ANCA-positive vasculitides, Behçet's disease, ankylosing spondylitis, sarcoidosis, and Sjögren's syndrome. Besides, aortitis may be idiopathic and isolated. Atherosclerosis should always be considered in the differential diagnosis of LVV. Other pathologies which may mimic LVV include, but not limited to, congenital causes of aortic coarctation and middle aortic syndrome, immunoglobulin G4-related disease, and hereditary disorders of connective tissue such as Marfan syndrome and Ehler-Danlos syndrome.

The Role of Ultrasound Compared to Biopsy of Temporal Arteries in the Diagnosis and Treatment of Giant Cell Arteritis (TABUL): a diagnostic accuracy and cost-effectiveness study

BACKGROUND

Giant cell arteritis (GCA) is a relatively common form of primary systemic vasculitis, which, if left untreated, can lead to permanent sight loss. We compared ultrasound as an alternative diagnostic test with temporal artery biopsy, which may be negative in 9-61% of true cases.

OBJECTIVE

To compare the clinical effectiveness and cost-effectiveness of ultrasound with biopsy in diagnosing patients with suspected GCA.

DESIGN

Prospective multicentre cohort study.

SETTING

Secondary care.

PARTICIPANTS

A total of 381 patients referred with newly suspected GCA.

MAIN OUTCOME MEASURES

Sensitivity, specificity and cost-effectiveness of ultrasound compared with biopsy or ultrasound combined with biopsy for diagnosing GCA and interobserver reliability in interpreting scan or biopsy findings.

RESULTS

We developed and implemented an ultrasound training programme for diagnosing suspected GCA. We recruited 430 patients with suspected GCA. We analysed 381 patients who underwent both ultrasound and biopsy within 10 days of starting treatment for suspected GCA and who attended a follow-up assessment (median age 71.1 years; 72% female). The sensitivity of biopsy was 39% [95% confidence interval (CI) 33% to 46%], which was significantly lower than previously reported and inferior to ultrasound (54%, 95% CI 48% to 60%); the specificity of biopsy (100%, 95% CI 97% to 100%) was superior to ultrasound (81%, 95% CI 73% to 88%). If we scanned all suspected patients and performed biopsies only on negative cases, sensitivity increased to 65% and specificity was maintained at 81%, reducing the need for biopsies by 43%. Strategies combining clinical judgement (clinician's assessment at 2 weeks) with the tests showed sensitivity and specificity of 91% and 81%, respectively, for biopsy and 93% and 77%, respectively, for ultrasound; cost-effectiveness (incremental net monetary benefit) was £485 per patient in favour of ultrasound with both cost savings and a small health gain. Inter-rater analysis revealed moderate agreement among sonographers (intraclass correlation coefficient 0.61, 95% CI 0.48 to 0.75), similar to pathologists (0.62, 95% CI 0.49 to 0.76).

LIMITATIONS

There is no independent gold standard diagnosis for GCA. The reference diagnosis used to determine accuracy was based on classification criteria for GCA that include clinical features at presentation and biopsy results.

CONCLUSION

We have demonstrated the feasibility of providing training in ultrasound for the diagnosis of GCA. Our results indicate better sensitivity but poorer specificity of ultrasound compared with biopsy and suggest some scope for reducing the role of biopsy. The moderate interobserver agreement for both ultrasound and biopsy indicates scope for improving assessment and reporting of test results and challenges the assumption that a positive biopsy always represents GCA.

FUTURE WORK

Further research should address the issue of an independent reference diagnosis, standards for interpreting and reporting test results and the evaluation of ultrasound training, and should also explore the acceptability of these new diagnostic strategies in GCA.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Color duplex ultrasonography findings of temporal arteries in a case of giant cell arteritis: role in diagnosis and follow-up

Giant cell arteritis (GCA) is a systemic autoimmune disease that affects medium- and large-sized arteries. The diagnostic gold standard is the temporal artery biopsy, but it has limited sensitivity and some difficulties in reproducibility. Color duplex ultrasonography is a noninvasive, reproducible, and inexpensive method for diagnosis of temporal arteries involvement (temporal arteritis [TA]) in GCA with high sensitivity and specificity. We present the ultrasound findings at baseline and during follow-up in a case of TA in a patient with GCA.

Giant Cell Arteritis and Polymyalgia Rheumatica: 2016 Update

Giant cell arteritis (GCA) and polymyalgia rheumatica (PMR) are both more common among people of North European decent than among Mediterranean people. Women are 2-3 times more commonly affected. Giant cell arteritis and PMR are extremely rare before age 50 years. Polymyalgia rheumatica may be "isolated" or associated with GCA. There is increased expression of inflammatory cytokines in temporal arteries of PMR patients, without overt histological evidence of arteritis. One-third of "isolated" PMR patients have vascular uptake in positron emission tomography (PET) scans, suggesting clinically unrecognized, "hidden" GCA. Typical manifestations of GCA are headache, tenderness over temporal arteries, jaw claudication, PMR, acute vision loss, and low-grade fever. Bilateral aching of the shoulders with morning stiffness is typical for PMR. In both conditions sedimentation rate and C-reactive protein are elevated, and anemia and thrombocytosis may occur. Color duplex ultrasonography of the temporal arteries may aid in GCA diagnosis. Temporal artery biopsy showing vasculitis, often with giant cells, confirms GCA diagnosis. In cases with negative biopsy one must rely on the clinical presentation and laboratory abnormalities. The diagnosis of PMR is made primarily on clinical grounds. Other conditions that may mimic GCA or PMR must be excluded. Glucocorticoids are the treatment of choice for both conditions. Prompt treatment is crucial in GCA, to prevent irreversible complications of acute vision loss and stroke. Addition of low-dose aspirin may further prevent these complications. The average duration of treatment is 2-3 years, but some patients require a prolonged course of treatment, and some may develop disease-related or treatment-related complications. No steroid-sparing agent has been proven to be widely effective thus far, but some promising therapeutic agents are currently being studied.

Giant Cell Arteritis: An Atypical Presentation Diagnosed with the Use of MRI Imaging

Giant cell arteritis (GCA) is the most common primary systemic vasculitis in western countries in individuals over the age of 50. It is typically characterised by the granulomatous involvement of large and medium sized blood vessels branching of the aorta with particular tendencies for involving the extracranial branches of the carotid artery. Generally the diagnosis is straightforward when characteristic symptoms such as headache, jaw claudication, or other ischemic complications are present. Atypical presentations of GCA without “overt” cranial ischemic manifestations have become increasingly recognised but we report for the first time a case of GCA presenting as mild upper abdominal pain and generalized weakness in the context of hyponatremia as the presenting manifestation of vasculitis that was subsequently diagnosed by MRI scanning. This case adds to the literature and emphasises the importance of MRI in the evaluation of GCA patients without “classic” cranial ischemic symptoms.

New developments in giant cell arteritis

Giant cell arteritis (GCA) is a medium-to-large vessel vasculitis with potentially sight- and life- threatening complications. Our understanding of the pathogenesis, diagnosis, and treatment of GCA has advanced rapidly in recent times. The validity of using the American College of Rheumatology guidelines for diagnosis of GCA in a clinical setting has been robustly challenged. Erythrocyte sedimentation rate, an important marker of inflammation, is lowered by the use of statins and nonsteroidal anti-inflammatory drugs. Conversely, it may be falsely elevated with a low hematocrit. Despite the emergence of new diagnostic modalities, temporal artery biopsy remains the gold standard. Evidence suggests that shorter biopsy lengths and biopsies done weeks to months after initiation of steroid therapy are still useful. New imaging techniques such as positron emission tomography have shown that vascular inflammation in GCA is more widespread than originally thought. GCA, Takayasu arteritis, and polymyalgia rheumatica are no longer thought to exist as distinct entities and are more likely parts of a spectrum of disease. A range of immunosuppressive drugs have been used in conjunction with corticosteroids to treat GCA. In particular, interleukin-6 inhibitors are showing promise as a therapy.

Clinic and Emergency Room Evaluation and Testing of Headache

BACKGROUND

Evaluation of the headache patient in the outpatient clinic and emergency department (ED) has different focuses and goals. The focus of this paper is to review the evaluation of patients in both settings with mention of evaluation in the pediatric and pregnant patient population.  The patient's history should drive the practitioner's decision and evaluation choices. We review recommendations made by the American Board of Internal Medicine and American Headache Society through the Choosing Wisely Campaign, which has an emphasis on choosing the right imaging modality for the clinical situation and elimination/prevention of medication overuse headache, as well as the US Headache Consortium guidelines for migraine headache. We will also review focusing on ED evaluation of the pediatric patient and pregnant patient presenting with headache.

CONCLUSION

At the end of the review we hope to have provided you with a framework to think about the headache patient and what is the appropriate test in the given clinical setting in order to ensure that the patient gets the right diagnosis and is set on a path to the appropriate management plan.

Clinical diagnosis and management of large vessel vasculitis: giant cell arteritis

Large vessel vasculitis (LVV) covers a spectrum of primary vasculitides predominantly affecting the aorta and its major branches. The two main subtypes are giant cell arteritis (GCA) and Takayasu arteritis (TA). Less commonly LVV occurs in various other diseases. Clinical manifestations result from vascular stenosis, occlusion, and dilation, sometimes complicated by aneurysm rupture or dissection. Occasionally LVV is discovered unexpectedly on pathological examination of a resected aortic aneurysm. Clinical evaluation is often unreliable in determining disease activity. Moreover, the diagnostic tools are imperfect. Acute phase reactants can be normal at presentation and available imaging modalities are more reliable in delineating vascular anatomy than in providing reliable information on degree of vascular inflammation. Glucocorticoids are the mainstay of therapy of LVV. Patients may develop predictable adverse effects from long-term glucocorticoid use. Several steroid-sparing agents have also shown some promise and are currently in use. Endovascular revascularization procedures and open surgical treatment for aneurysms and dissections are sometimes necessary, but results are not always favorable and relapses are common. This article, the first in a series of two, will be devoted to GCA and isolated (idiopathic) aortitis, while TA will be covered in detail in the next article.

Inflamed temporal artery: histologic findings in 354 biopsies, with clinical correlations

We reviewed 888 temporal artery biopsies (TAB) performed in 871 patients in a single institution from January 1986 to December 2013. Forty-four biopsies (4.9%) were inadequate, 490 (55.2%) were devoid of inflammation and were considered negative, and 354 (39.9%) showed inflammation and were considered positive. On the basis of the localization of the inflammation, positive TABs were further classified into 4 categories: small vessel vasculitis (SVV), in which inflammation was limited to small periadventitial vessels devoid of muscular coat, with sparing of the temporal artery (32 cases, 9% of the positive biopsies); vasa vasorum vasculitis (VVV), in which inflammation was limited to the adventitial vasa vasorum (23 cases, 6.5% of the positive biopsies); inflammation limited to adventitia (ILA), in which inflammation extended from a strictly perivascular localization to the surrounding adventitia, without medial involvement (25 cases, 7% of the positive biopsies); and transmural inflammation (TMI), in which inflammation crossed the external elastic lamina and extended to the media (274 cases, 77.5% of the positive biopsies). In TMI, inflammation was generally more prominent between media and adventitia and mostly consisted of T lymphocytes and macrophages, with occasionally a significant number of plasma cells. Numerous eosinophils or neutrophils (with or without leucocytoclasia and suppurative necrosis), fibrinoid necrosis (limited to small branches of the temporal artery), and acute thrombosis were unusual, being present in 8%, 1.8%, 0.7%, and 9.5% of our biopsies with TMI, respectively. Giant cells, laminar necrosis, and calcifications prevailed along the internal elastic lamina and were present in 74.8%, 25.2%, and 20% of the biopsies with TMI, respectively. Among the 322 patients with positive TAB on whom we obtained clinical information, 317 had giant cell arteritis and 5 had a different disease: 3 (with SVV at histology) had ANCA-associated vasculitis, 1 (with SVV with amyloid deposits) had primary systemic amyloidosis, and 1 (with TMI limited to a small branch) had polyarteritis nodosa. In none of these cases the biopsy showed fibrinoid necrosis or significant numbers of eosinophils or neutrophils. Considering the 317 patients with giant cell arteritis, those with SVV and VVV compared with those with TMI had a significantly lower frequency of cranial manifestation (including headache, jaw claudication, and abnormalities of temporal arteries), lower serum levels of acute-phase reactants, and a reduced frequency of prednisone therapy at the time of TAB, of the "halo sign" at color duplex sonography of temporal arteries, and of systemic symptoms (for VVV). Polymyalgia rheumatica and blindness were equally represented in all patients groups, whereas there was a higher frequency of male sex and peripheral arthritis in patients with SVV. Patients with ILA were more similar to those with TMI, having a lower frequency of headache, of abnormalities of temporal arteries, and of a positive "halo sign" at color duplex sonography of temporal arteries. In conclusion, the histologic spectrum of inflammatory lesions that can be found in TAB is broad, and the differences have clinical implications.

The diagnosis and classification of giant cell arteritis

Giant-cell arteritis (GCA) involves the major branches of the aorta with predilection for the extracranial branches of the carotid artery. It occurs in individuals older than 50 years and the incidence increases with age. The signs and symptoms of giant cell arteritis can be classified into four subsets: cranial arteritis, extracranial arteritis, systemic symptoms and polymyalgia rheumatica. Patients may develop any combination of these manifestations, associated with laboratory evidence of an acute-phase reaction. The only test that confirms GCA diagnosis is a temporal artery biopsy, showing vasculitis with mononuclear cell inflammatory infiltrates, often with giant cells. Due to the focal and segmental nature of the infiltrates, areas of inflammation may be missed by the biopsy and the histological examination is normal in about 15% of the cases. Some imaging modalities may aid in the diagnosis of GCA. Among those, color duplex ultrasonography of the temporal arteries is more commonly used. There are no independent validating criteria to determine whether giant cell arteritis is present when a temporal artery biopsy is negative. The American College of Rheumatology criteria for the classification of giant cell arteritis may assist in the diagnosis. However, meeting classification criteria is not equivalent to making the diagnosis in individual patients, and the final diagnosis should be based on all clinical, laboratory, imaging and histological findings. Glucocorticoids are the treatment of choice for GCA. The initial dose is 40-60 mg/day for most uncomplicated cases. Addition of low-dose aspirin (100 mg/d) has been shown to significantly decrease the rate of vision loss and stroke during the course of the disease.

Temporal arteritis

Temporal or giant cell arteritis is an inflammation of medium and small extracranial vessels that may result in ocular ischemia, an aortitis followed by aortic dissection and peripheral limb ischemia. It should be considered a medical emergency due to the seriousness of end organ damage, in particular visual symptoms. While the presentation may be nonspecific, the presence of a tender temporal artery mandates a temporal artery biopsy. High-dose steroids should be begun the moment the diagnosis is considered and only withdrawn once it has been excluded. A gradual tapering of the steroid dose should occur over at least 1 year, with the consideration of the use of steroid-sparing agents if iatrogenic steroid complications occur. Careful monitoring of the response both clinically as well as with serial inflammatory markers is required.

Nonarteriosclerotic vascular disease

Thromboangiitis obliterans, or Buerger disease, is a chronic nonatherosclerotic endarteritis manifesting as inflammation and thrombosis of distal extremity small and medium-sized arteries resulting in relapsing episodes of distal extremity ischemia. Takayasu arteritis is a rare syndrome characterized by inflammation of the aortic arch, pulmonary, coronary, and cerebral vessels, presenting with cerebrovascular symptoms, myocardial ischemia, or upper extremity claudication in young, often female, patients. Kawasaki disease is a small- and medium-vessel acute systemic vasculitis of young children, with morbidity and mortality stemming from coronary artery aneurysms. Microscopic polyangiitis, Churg-Strauss syndrome, and Wegener granulomatosis are systemic small-vessel vasculitides, affecting arterioles, capillary beds and venules, and each presenting with variable effects on the pulmonary, renal and gastrointestinal systems.

The use of temporal artery ultrasound in the diagnosis of giant cell arteritis in routine practice

AIM

The exact diagnostic role of temporal artery ultrasound (TAU) remains unclear. The aim of this study was to determine the sensitivity and specificity of a positive halo sign in patients undergoing TAU in a clinical setting, and to perform a review of existing evidence.

METHOD

Patients who had undergone TAU at a single centre in Australia were included in the study. The presence or absence of a halo sign and whether it was unilateral or bilateral was determined retrospectively from radiology reports. Pathology results were used to determine which patients underwent a temporal artery biopsy and if the biopsy was positive or negative. A case note review was performed to determine presenting clinical features and if a clinical diagnosis of giant cell arteritis was made. The sensitivity, specificity and likelihood ratios of TAU compared to both biopsy and clinical diagnosis were calculated.

RESULTS

Fifty patients were identified as having had a TAU (28% male, mean age 69). When compared to biopsy-proven cases, the sensitivity of a halo sign was 40%, specificity 81%, positive likelihood ratio 2.1 and negative likelihood ratio 0.7. When compared to clinical diagnosis, the sensitivity was 42%, specificity 94%, positive likelihood ratio 7.1 and negative likelihood 0.6.

CONCLUSIONS

Sensitivity and specificity results were comparable to the literature. A halo sign may preclude the need for biopsy in cases of high clinical suspicion and contraindications to surgery. Biopsy remains necessary in most cases, irrespective of whether a halo sign is present.

Headache and temporal arteritis: when to suspect and how to manage

Temporal arteritis, also termed giant cell arteritis, is one of the vasculitides affecting large and medium sized cranial arteries, particularly of the carotid tree. Clinical manifestations may vary from the classic constellation of temporal headache in the elderly accompanied by constitutional signs, jaw claudication, and visual symptoms; therefore, a high index of clinical suspicion may be necessary to identify the disorder. Once suspected, immediate treatment is crucial while exploring any number of diagnostic tools to confirm or refute the diagnosis, since morbidity from untreated temporal arteritis can be devastating. At the same time, achieving a definitive diagnosis is paramount, as treatment can be toxic with significant morbidity of its own. Temporal artery biopsy remains the gold standard, but noninvasive diagnostic approaches are being refined. Corticosteroids remain the cornerstone of treatment, but are ineffective for, not tolerated by, or contraindicated in some individuals, necessitating the exploration of alternatives.

Clinical features of polymyalgia rheumatica and giant cell arteritis

Polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) are inflammatory diseases that typically affect white individuals >50 years. Women are affected ∼2-3 times more often than men. PMR and GCA occur together more frequently than expected by chance. The main symptoms of PMR are pain and stiffness in the shoulders, and often in the neck and pelvic girdle. Imaging studies reveal inflammation of joints and bursae of the affected areas. GCA is a large-vessel and medium-vessel arteritis predominantly involving the branches of the aortic arch. The typical clinical manifestations of GCA are new headache, jaw claudication and visual loss. PMR and GCA usually remit within 6 months to 2 years from disease onset. Some patients, however, have a relapsing course and might require long-standing treatment. Diagnosis of PMR and GCA is based on clinical features and elevated levels of inflammatory markers. Temporal artery biopsy remains the gold standard to support the diagnosis of GCA; imaging studies are useful to delineate large-vessel involvement in GCA. Glucocorticoids remain the cornerstone of treatment of both PMR and GCA, but patients with GCA require higher doses. Synthetic immunosuppressive drugs also have a role in disease management, whereas the role of biologic agents is currently unclear.

Polymyalgia rheumatica and giant cell arteritis in older patients: diagnosis and pharmacological management

Giant cell arteritis (GCA) is an inflammatory vasculopathy that involves large- and medium-sized arteries and can cause vision loss, stroke and aneurysms. GCA occurs in people aged >50 years and is more common in women. A higher incidence of the disease is observed in populations from Northern European countries. Polymyalgia rheumatica (PMR) is a periarticular inflammatory process manifesting as pain and stiffness in the neck, shoulders and pelvic girdle. PMR shares the same pattern of age and sex distribution as GCA. The pathophysiology of PMR and GCA is not completely understood, but the two conditions may be related and often occur concurrently. A delay in the diagnosis should be avoided because of the risk of vascular ischaemic complications due to GCA. The diagnosis should be considered in patients aged >50 years presenting with symptoms such as new headache, visual disturbances, jaw claudication or symptoms of PMR. GCA can also present as a systemic inflammatory syndrome with fever of unknown origin. Marked elevation of acute-phase reactants, recognizable in higher erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels, is often seen in both PMR and GCA. However, some patients can present with a normal ESR. Confirmation of the diagnosis of GCA by temporal artery biopsy is important because clinical findings and laboratory tests are not specific, and because a diagnosis of GCA commits patients to long-term treatment with corticosteroids. The role of imaging techniques for the diagnosis of GCA remains unclear, but these modalities can be helpful in assessing the extent of vascular involvement, especially when extra-cranial disease is present. In PMR, subdeltoid and subacromial bursitis can be identified by imaging techniques, especially ultrasound or MRI. The clinical manifestations of GCA and PMR respond dramatically within 12-48 hours of starting corticosteroid treatment. The initial corticosteroid dosage commonly used in GCA is oral prednisone 40-60 mg/day, and for patients with PMR a dosage of 15-20 mg/day is often sufficient. A prolonged course of treatment is necessary, and corticosteroids are gradually tapered, guided by regular clinical evaluation and ESR (and/or CRP) measurement. Methotrexate is the best studied corticosteroid-sparing agent in GCA, and may be useful for patients with frequent disease relapses and/or corticosteroid-related toxicity. Retrospective studies favour aspirin (acetylsalicylic acid) as an effective adjuvant treatment for reducing the ischaemic complications of GCA. The long-term course of corticosteroid therapy frequently exposes elderly patients with PMR/GCA to various adverse effects, which can be attenuated with appropriate prophylactic measures. Co-morbid diseases and polypharmacy can pose particular challenges in the geriatric population. In general, the life expectancy of patients with GCA does not appear to be shortened, whereas the morbidity associated with the disease and its treatment is well recognized.

Giant cell arteritis: epidemiology, diagnosis, and management

Giant cell arteritis (GCA), also called temporal arteritis, is a vasculitis that affects large and middle-sized blood vessels--with predisposition to the involvement of cranial arteries derived from the carotid artery--in individuals older than 50 years of age. Familial aggregation of GCA has been observed. Incidence of GCA is higher in white individuals than those of other ethnicities, particularly those of Scandinavian background. A temporal artery biopsy is the gold standard test for the diagnosis of GCA. Several imaging modalities, in particular ultrasonography, are useful in the diagnosis of GCA. Corticosteroids are the cornerstone of treatment in GCA. Alternative, steroid-sparing drugs, particularly methotrexate, should be considered in GCA patients with severe corticosteroid-related side effects and/or in those who require prolonged corticosteroid therapy due to relapses of the disease.