Giant cell arteritis: strategies in diagnosis and treatment

Diagnosis of giant cell arteritis by temporal artery biopsy is associated with biopsy length

Aims

Temporal artery biopsy (TAB) is a widely used method for establishing a diagnosis of Giant Cell Arteritis (GCA). The optimal TAB length for accurate histological GCA diagnosis has been suggested as 15 mm post-fixation (15-20 mm pre-fixation). The aim of this study was to determine the relationship between a histological GCA diagnosis and optimal TAB length in the South Australian (SA) population.

Materials and methods

Pre-fixation TAB length (mm) was reported in 825/859 of all samples submitted to SA Pathology between 2014 and 2020 from people aged 50 and over. When more than one biopsy was taken, the longest length was recorded. Analyses of both TAB length and TAB positive proportions were performed by multivariable linear and logistic regression analysis, including covariates sex, age, and calendar year.

Results

The median age of participants was 72 (IQR 65, 79) years, 549 (66%) were female. The TAB positive proportion was 172/825 (21%) with a median biopsy length of 14 mm (IQR 9, 18). Biopsy length (mm) was shorter in females (p = 0.001), increased with age (p = 0.006), and a small positive linear trend with calendar year was observed (p = 0.015). The TAB positive proportion was related to older age (slope/decade: 6, 95% CI 3.6, 8.3, p < 0.001) and to TAB length (slope/mm 0.6, 95% CI 0.2, 0.9, p = 0.002), but not sex or calendar year. Comparison of models with TAB length cut-points at 5, 10, 15, 20 mm in terms of diagnostic yield, receiver operating characteristics and Akaike Information Criteria confirmed ≥ 15 mm as an appropriate, recommended TAB length. However, only 383 (46%) of the biopsies in our study met this criteria. The diagnostic yield at this cut-point was estimated as 25% which equates to an expected additional 30 histologically diagnosed GCA patients.

Conclusion

This study confirms that TAB biopsy length is a determinant of a histological diagnosis of temporal arteritis, and confirms that a TAB length ≥ 15 mm is optimal. Approximately half the biopsies in this study were shorter than this optimal length, which has likely led to under-diagnosis of biopsy-proven GCA in SA. Further work is needed to ensure appropriate TAB biopsy length.

Vasculitis syndrome-diagnosis and therapy

In patients with connective tissue disease, vascular injury induced by primary or secondary vasculitis syndromes can lead to organ dysfunction due to the loss of nutrient supply from the blood. Such vasculitis syndromes can be refractory to treatment and fatal. The nomenclature and the definition of vasculitis syndromes have recently been revised, and clinical practice guidelines for diseases associated with vasculitis syndrome are evolving. The present review provides an overview of vasculitis syndromes from the viewpoint of diagnosis and treatment.

Studies on the Histopathology of Temporal Arteritis

AIMS

The aim of this paper was to identify the location and to grade the severity of most significant inflammation within positive temporal artery biopsies along with other key clinical and histologic characteristics.

METHODS

Charts and pathology slides for 70 patients diagnosed with temporal arteritis at the University of Wisconsin (UW) Hospital and Clinics from 1989 to 2015 were reviewed. A subset of 48 specimens was immunostained for CD68 and graded on a scale from 0 to +++; the location of staining was recorded.

RESULTS

The most severe granulomatous inflammation was in the media and adventitia in 13% (9/70) of the biopsies; the remaining had uniform full thickness inflammation. Of the slides that were stained with CD68, 94% (45/48) were positive. In 42% (19/45), the stained cells were found mainly in the muscularis and adventitia. Seven percent (3/45) of the slides had staining solely around the internal elastic lamina, and 2% (1/45) had staining limited to the intima.

CONCLUSIONS

With a few exceptions, granulomatous inflammation in positive temporal artery biopsies is most evident at the media and adventitia or is uniform throughout the layers of the artery. Our study lends support to the theory that the muscularis and adventitia may play an inciting role in the pathogenesis of temporal arteritis.

Temporal artery biopsies: do they make the cut?

BACKGROUND AND AIMS

Temporal artery biopsy is the gold standard investigation for giant cell arteritis. Guidelines recommend that specimens should measure no less than 1 cm and ideally more than 2 cm in length, as this influences the likelihood of biopsy positivity. This audit investigates the extent to which temporal artery biopsies acquired in our hospital meet these guidelines.

METHODS

Histopathology reports for all temporal artery biopsies performed at University Hospital Ayr between January 2011 and June 2013 were examined.

RESULTS

Fifty-six temporal artery biopsy specimens showed a range in length from 0.5 cm to 3.1 cm, with a mean of 1.4 cm. Thirty-seven biopsies measured ≥1 cm (66%) and 13 were ≥2 cm (23%). Therefore, 19 samples (34%) did not meet the recommended standard. Just seven biopsies showed features of giant cell arteritis, with six of these measuring ≥1 cm in length (86%).

CONCLUSION

The guidelines for temporal artery specimens are not being met at our centre. Furthermore, biopsies measuring ≥1 cm are much more common in the small group of positive results. This validates the minimum recommended biopsy length and displays the importance of achieving this standard. We suggest changes to increase the number of biopsies meeting these guidelines, improving the accuracy of this invasive test.

The thromboembolic risk in giant cell arteritis: a critical review of the literature

Giant cell arteritis is a systemic vasculitis characterized by granulomatous inflammation of the aorta and its main vessels. Cardiovascular risk, both for arterial and venous thromboembolism, is increased in these patients, but the role of thromboprophylaxis is still debated. It should be suspected in elderly patients suffering from sudden onset severe headaches, jaw claudication, and visual disease. Early diagnosis is necessary because prognosis depends on the timeliness of treatment: this kind of arteritis can be complicated by vision loss and cerebrovascular strokes. Corticosteroids remain the cornerstone of the pharmacological treatment of GCA. Aspirin seems to be effective in cardiovascular prevention, while the use of anticoagulant therapy is controversial. Association with other rheumatological disease, particularly with polymyalgia rheumatica is well known, while possible association with antiphospholipid syndrome is not established. Large future trials may provide information about the optimal therapy. Other approaches with new drugs, such as TNF-alpha blockades, Il-6 and IL-1 blockade agents, need to be tested in larger trials.

Temporal artery biopsy--how can we improve performance?

INTRODUCTION

Temporal arteritis is a rare systemic disease of undefined aetiology. The British Society for Rheumatology has issued evidence-based guidance in the form of an investigative algorithm, central to which is biopsy of the superficial temporal artery (TA). Currently in Glasgow these patients are being referred to the regional vascular unit. We sought to identify areas where local practice could be improved.

METHODS

This was a retrospective review of TA biopsy performed since the amalgamation of vascular services in Glasgow.

RESULTS

There were 32 cases with a complete dataset. The majority of patients referred were women (66%), with a mean age of 68 years (range 43-86 years). A variety of different clinical symptoms were reported. The mean ESR was 53 (range 2-122). The median waiting time from referral to surgical biopsy was 6 days (inter-quartile range 2-8 days). Seven patients waited for more than 14 days for the procedure to be performed. There were four positive biopsies in this case series. TA biopsy influenced the duration of glucocorticosteroid therapy.

CONCLUSION

From this study we believe that the following changes to local practice would be simple, cost effective and could improve the quality of patient care delivered.

Isolated superficial temporal artery dissection masquerading as giant cell arteritis

A 79-year-old male presented with symptoms suggesting giant cell arteritis (GCA) and elevation of acute-phase reactants. Bilateral superficial temporal artery (STA) biopsies were negative for GCA. However, the right-sided biopsy showed a STA dissection. Spontaneous isolated STA dissection has never been reported previously. The pertinent available literature is also discussed.

Giant cell arteritis: an updated review

Giant cell arteritis (GCA) is the most common primary vasculitis of adults. The incidence of this disease is practically nil in the population under the age of 50 years, then rises dramatically with each passing decade. The median age of onset of the disease is about 75 years. As the ageing population expands, it is increasingly important for ophthalmologists to be familiar with GCA and its various manifestations, ophthalmic and non-ophthalmic. A heightened awareness of this condition can avoid delays in diagnosis and treatment. It is well known that prompt initiation of steroids remains the most effective means for preventing potentially devastating ischaemic complications. This review summarizes the current concepts regarding the immunopathogenetic pathways that lead to arteritis and the major phenotypic subtypes of GCA with emphasis on large vessel vasculitis, novel modalities for disease detection and investigative trials using alternative, non-steroid therapies.

Secondary cicatricial and other permanent alopecias

Various nonfollicular scalp conditions can cause secondary scarring or permanent alopecia. Possible causes are congenital defects, trauma, inflammatory conditions, infections, and neoplasms (rarely drugs). Associated signs and symptoms and other diagnostic procedures such as histopathology may aid in the diagnosis. Detection of the underlying disorder may be difficult in end-stage lesions. Treatment is specific for active conditions. Surgery and hair transplantation are options for localized scars.

Biopsy-negative giant cell arteritis: Does anti-CD83 immunohistochemistry advance the diagnosis?

BACKGROUND

In situ maturation of adventitial dendritic cells (DC) with expression of CD83 has been proposed as an early event in the pathogenesis of giant cell arteritis (GCA), preceding the appearance of an inflammatory infiltrate. The aim of this study was to evaluate the added value of anti-CD83 staining of temporal artery biopsy (TAB) specimens in patients with biopsy-negative temporal arteritis.

METHODS

Fourteen patients with TAB performed in our medical center since 2001 and considered negative for GCA due to the absence of any inflammatory infiltrate were identified by a computerized search of patient records. Their paraffin-embedded TAB specimens were retrieved, reprocessed, and stained with anti-CD83 monoclonal antibody (Serotec, 1:40). Three TAB specimens of patients with biopsy-proven GCA served as positive controls and three specimens of popliteal and/or tibial arteries of patients with atherosclerotic peripheral vascular disease were used as negative controls. Follow-up of the patients was confirmed by personal contact with their rheumatologists and analysis of their hospital charts.

RESULTS

Follow-up was available for 12 of 14 patients. Five of these patients were considered to have biopsy-negative GCA: they satisfied the ACR classification criteria, were successfully treated with glucocorticosteroids, and had a follow-up of at least 10 months with no alternative diagnosis established. Anti-CD83 staining was negative in all but one patient who demonstrated a single CD83-positive cell adjacent to the internal elastic membrane. Positive anti-CD83 staining of the inflammatory infiltrate throughout the arterial wall was observed in all patients with biopsy-proven GCA (positive controls). Negative controls did not show any CD83-positive cells.

CONCLUSIONS

In this pilot study, anti-CD83 immunohistochemical staining of paraffin-embedded specimens did not improve the yield of TAB in patients with suspected GCA.

THE LENGTH OF SUPERFICIAL TEMPORAL ARTERY BIOPSIES

BACKGROUND

To compare temporal artery biopsy specimen lengths from a tertiary care and a community hospital in New South Wales to recommended clinical guidelines in suspected giant cell arteritis.

DESIGN

A retrospective observational study of all patients who underwent temporal artery biopsy at Bathurst Base Hospital (BBH) and Royal Prince Alfred Hospital (RPAH) over a 5-year period.

METHODS

Patients who underwent temporal artery biopsy during the 5-year period were identified using computerized hospital databases. A retrospective chart review was carried out on all cases. Data were collected regarding patient age, patient sex, length of biopsy specimen, histopathological results and surgical team carrying out the biopsy.

RESULTS

During the 5-year period, 157 temporal artery biopsies were carried out at both hospitals, with 38/157(24%) at BBH and 119/157 (76%) at RPAH. There was no significant difference in biopsy length at the two hospitals. The mean specimen length at BBH was 12.1 mm compared with 11.7 mm at RPAH (t=0.35; P=0.73). At RPAH, there was no significant difference in specimen length between the surgical specialties carrying out the biopsy (ANOVA F=1.37; P=0.26). Specimens of length 20 mm or greater were 2.8 times more likely to show features of giant cell arteritis than those less than 20 mm.

CONCLUSION

The mean length of temporal artery biopsy specimens at both hospitals was substantially shorter than recommended guidelines of a minimum 20 mm. We recommend all surgeons carrying out temporal artery biopsies ensure a specimen of sufficient length is obtained.

Giant Cell Arteritis

Giant cell arteritis is a relatively common form of systemic vasculitis, best known for its predisposition to affect the extracranial branches of the carotid artery and associated potential for visual loss. Additional vascular manifestations include stroke, aortic aneurysm or dissection, and even aortic rupture. Cardiac manifestations include coronary artery disease, aortic valve insufficiency, or left ventricular dysfunction, which may occur independently from the valvular disease or hypertension. Physicians need to be vigilant for this disorder, particularly because the tragic end-organ outcomes such as visual loss can be effectively prevented with early use of corticosteroids. We review the pathophysiology and clinical manifestations of giant cell arteritis and present a rationale for diagnosis and therapy for this disease.

Prevalence of a Normal C-Reactive Protein with an Elevated Erythrocyte Sedimentation Rate in Biopsy-Proven Giant Cell Arteritis

OBJECTIVE

The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are laboratory tests that have been said to have a strong correlation with a positive temporal artery biopsy in patients with suspected giant cell arteritis (GCA). Published reports suggest that the CRP is a more sensitive diagnostic indicator of GCA and can be elevated when the ESR is normal. It is also clear that the CRP and ESR can both be normal or both be elevated in patients with biopsy-proven GCA and that the CRP can be elevated when the ESR is normal. The purpose of this study was to ascertain if the CRP can be normal when the ESR is elevated in biopsy-proven GCA.

DESIGN

Retrospective, longitudinal, comparative study.

PARTICIPANTS

One hundred nineteen patients from 6 major tertiary-care university-affiliated medical centers.

METHODS

The charts from 119 patients with temporal artery biopsies positive for GCA were reviewed for age, gender, pretreatment ESR, and pretreatment CRP.

MAIN OUTCOME MEASURES

The ESR in millimeters per hour Westergren was graded as normal or abnormal based on 2 validated formulas. The CRP was graded as normal or abnormal based on established criteria set forth in the literature as well as at The Johns Hopkins Hematology laboratory.

RESULTS

In this study, the ESR had a sensitivity of 76% to 86%, depending on which of 2 formulas were used, whereas an elevated CRP had a sensitivity of 97.5%. The sensitivity of the ESR and CRP together was 99%. Only 1 of the 119 patients (0.8%) presented with a normal ESR and normal CRP (double false negative); 2 patients (1.7%) had a normal CRP despite an elevated ESR according to both formulas.

CONCLUSION

Although most patients with GCA have both an elevated ESR and CRP, there can be nonconcordance of the 2 blood tests. Although such nonconcordance is most often a normal ESR but an elevated CRP, the finding of an elevated ESR and a normal CRP also is consistent with GCA. The use of both tests provides a slightly greater sensitivity for the diagnosis of GCA than the use of either test alone.

Vascular dendritic cells in giant cell arteritis

Giant cell arteritis (GCA) is a granulomatous vasculitis that selectively targets medium-sized and large arteries, especially the cranial branches of the aorta. The inflammatory activity of vascular lesions is driven by adaptive immune responses, with CD4 T cells undergoing clonal expansion in the vessel wall and releasing interferon gamma. Recent studies have described a distinctive population of dendritic cells (DCs) localized at the adventitia-media border of normal medium-sized arteries that appear to play a critical role in the initiation of vasculitis. Immune effector functions of this DC population are being examined in human artery-severe combined immunodeficient (SCID) mouse chimeras. In their constitutive form, CD11c+ fascin+ adventitial DCs are not recognized by alloreactive T cells. Triggering with Toll-like receptor (TLR) ligands is sufficient to break this state of tolerance and initiate DC activation, T-cell recruitment, T-cell activation, and T-cell retention in the arterial wall. Systemic administration of ligands for TLR2 or -4 in human artery-SCID chimeras drives differentiation of adventitial DCs into chemokine-producing effector cells with high-level expression of both CD83 and CD86 and mediates T-cell regulatory function through release of interleukin 18. In established vasculitis, fully matured DCs retain antigen-presenting function; antibody-mediated DC depletion disrupts T-cell and macrophage activation and has marked anti-inflammatory effects. We conclude that adventitial DCs, an indigenous cell population of the arterial wall, are responsive to pathogen-derived macromolecules and have gatekeeper function in regulating T-cell recruitment and retention to the arterial adventitia. A switch of adventitial DCs from being nonstimulatory to T-cell activating emerges as a critical event in the initiation of vasculitis.

Orofacial Pain--Part II: Assessment and management of vascular, neurovascular, idiopathic, secondary, and psychogenic causes

Chronic orofacial pain is a common health complaint faced by health practitioners today and constitutes a challenging diagnostic problem that often requires a multidisciplinary approach to diagnosis and treatment. The previous article by the same authors in this issue discussed the major clinical characteristics and the treatment of various musculoskeletal and neuropathic orofacial pain conditions. This second article presents aspects of vascular, neurovascular, and idiopathic orofacial pain, as well as orofacial pain due to various local, distant, or systemic diseases and psychogenic orofacial pain. The emphasis in this article is on the general differential diagnosis and various therapeutic regimens of each of these conditions. An accurate diagnosis is the key to successful treatment of chronic orofacial pain. Given that for many of the entities discussed in this article no curative treatment is available, current standards of management are emphasized. A comprehensive reference section has been included for those who wish to gain further information on a particular entity.

Horton’s disease: Past and present

Although the disease known as temporal arteritis, giant cell arteritis, and Horton's disease has been known since at least the 10th century, Hutchinson (1890) and Horton (1932) characterized the condition in the more recent medical literature. The diagnosis of this potentially serious illness can be surprisingly elusive, and treatment is fraught with some frustrating pitfalls. For the most part, careful evaluation of patients (usually elderly) with the typical presentation of head pain and constitutional signs yields prompt diagnosis. Treatment with corticosteroids, the standard since the mid-1950s, is usually very successful in relieving pain and tenderness and in preventing visual and other sequelae. This article discusses the evolution of medical understanding of the disease, pathophysiology, diagnosis, and modern treatment options.

Are steroids alone sufficient for the treatment of giant cell arteritis?

Glucocorticosteroids are the cornerstone of treatment of giant cell arteritis. An initial dose of prednisone or its equivalent of at least 40-60mg per day as single or divided dose is usually adequate. Glucocorticosteroids may prevent, but usually do not reverse, visual loss. A treatment course of 1-2 years is often required. Some patients, however, have a more chronic-relapsing course and may require low doses of glucocorticosteroids for several years. Glucocorticosteroid-related adverse events are common. In studies on immunosuppressant agents, methotrexate has been used as a glucocorticosteroid-sparing drug with conflicting results. This drug may, however, be given to patients who need high doses of glucocorticosteroids to control active disease and who have serious side effects. A recent pilot study found that infliximab was efficacious in patients with glucocorticosteroid-resistant giant cell arteritis. However, randomized controlled trials are required to define the role of anti-tumor necrosis factor-alpha agents in the treatment of giant cell arteritis. Finally, low-dose aspirin has been shown in a recent retrospective study to decrease the rate of cranial ischemic complications secondary to giant cell arteritis. It is conceivable that the definition of different patterns of inflammation in giant cell arteritis in the future might facilitate the design of differentiated therapeutic approaches.

Use of ultrasonography and positron emission tomography in the diagnosis and assessment of large-vessel vasculitis

PURPOSE OF REVIEW

Ultrasonography and positron emission tomography have been increasingly studied and, in part, introduced in clinical practice to diagnose large-vessel vasculitides, such as temporal arteritis, Takayasu arteritis, large-vessel giant cell arteritis, and isolated aortitis.

RECENT FINDINGS

Ultrasonography reveals characteristic homogenous, concentric wall thickening in vasculitis, often combined with stenoses and, less frequently, with acute occlusions. Thirteen studies describe sensitivities of 40 to 100% (median, 86%) for temporal artery vessel wall edema compared with histology, and of 35 to 86% (median, 70%) compared with clinical diagnosis. If wall edema, stenoses, and occlusions are included, sensitivities increase to 91 to 100% (median, 95%) compared with histology, and to 83 to 100% (median, 88%) compared with clinical diagnosis. Specificities for wall edema are 68 to 100% (median, 93%) compared with histology, and 78 to 100% (median, 97%) compared with clinical diagnosis. One should be aware of large-vessel giant cell arteritis in all patients with temporal arteritis and polymyalgia rheumatica. Ultrasonography reveals characteristic wall thickening, particularly of the distal subclavian, axillary, and proximal brachial arteries. Findings in Takayasu arteritis are similar, but the vessel wall swelling is usually brighter. Positron emission tomography reveals vasculitis in arteries with a diameter of more than 4 mm. Ultrasonography and positron emission tomography agreed completely in the anatomic distribution of changes in patients with large-vessel giant cell arteritis. It reveals asymptomatic large-vessel vasculitis in giant cell arteritis and Takayasu arteritis. Positron emission tomography is not suitable for the assessment of temporal arteries.

SUMMARY

Ultrasonography and positron emission tomography are new, promising techniques to assess large-vessel vasculitides.

Headache caused by giant cell arteritis

Giant cell arteritis (GCA) is the most common primary systemic vasculitis in older adults. Patients usually are older than 50 years and have an erythrocyte sedimentation rate (Westergren) greater than 50 mm/h. Headache is a common symptom, occurring in approximately 90% of patients. However, the most serious complications of GCA, blindness and stroke, may occur in the absence of headache. Nonspecific constitutional symptoms such as weight loss, fever, and malaise may dominate the clinical presentation. Currently, corticosteroids are the mainstay of therapy for GCA. Treatment is initiated at 0.7 to 1 mg/kg mg of prednisone (or equivalent) per day as soon as the diagnosis is suspected. The medication is tapered based on laboratory parameters and symptoms. Relapse is common, especially during the first year of therapy. Side effects from steroids in the elderly are common and often serious. Steroid resistance (manifesting as continued high dose requirements after 3 to 6 months) may complicate therapy and place patients at increased risk of side effects. Methotrexate and azathioprine have been used as steroid-sparing agents based on anecdotal evidence. More recently, evidence is emerging that antitumor necrosis factor-alpha agents may be efficacious and act as steroid-sparing agents. New-onset headache or worsening headache in a patient older than 50 years should raise the possibility of GCA and appropriate therapeutic and diagnostic measures should be begun promptly.