Giant Cell Arteritis
- 1 Disease Entity
- 2 Diagnosis
- 3 Clinical diagnosis
- 4 Management
- 5 References
Disease Entity[edit | edit source]
Disease[edit | edit source]
Giant cell arteritis (GCA), the most common primary vasculitis in adults, is a generalized granulomatous inflammation of medium- to large-sized vessels that occurs in the elderly. The condition is also known as temporal arteritis. Based on United States census data from 2000, the prevalence of GCA is approximately 160,000. Since patients with GCA often present with vision loss, ophthalmologists are on the front lines of diagnosing the disorder. In addition to vision loss, patients commonly note associated symptoms such as headache, jaw claudication, visual loss, diplopia, myalgias, and constitutional symptoms. The most commonly feared sequela of GCA is permanent visual loss secondary to arteritic anterior ischemic optic neuropathy (AAION). Since the vision loss from AAION can progress rapidly, and can involve the fellow eye within a matter of days, GCA is considered an ophthalmologic emergency. When GCA is suspected, treatment with corticosteroids is indicated on an urgent basis, as further vision loss and fellow eye involvement are usually preventable. There is much research and discussion regarding the underlying etiology, pathogenesis, and appropriate management of patients with GCA. This review serves to highlight the essential concepts in our current understanding of the management of patients with GCA.
Etiology[edit | edit source]
The underlying etiology of GCA has been widely researched, yet is still not well understood. In successive studies of a stable population in Minnesota, there appeared to be a cyclic fluctuation in the incidence of GCA, thus supporting an infectious or environmental factor.  A range of infectious stimuli have been implicated, including Chlamydia pneumoniae, varicella virus, and parvovirus B19.  However, there are conflicting reports that argue against these infectious stimuli in select patients.  and it is unclear if the infectious associations are simply coincidental. Additionally, some have suggested that an endogenous element in the arterial wall stimulates the initial inflammatory event.
In response to the heretofore undefined stimulus, activated T-cells in the vasa vasorum of medium and large vessels up-regulate and activate macrophages, which then form a granulomatous immune reaction. Metalloproteinases and reactive oxygen intermediates expressed by macrophages ultimately cause destruction within the blood vessel wall. After this initial immune response, the vessel undergoes a healing response to injury, which includes intimal thickening, myofibroblast proliferation, and extracellular matrix deposition – all of which contribute to vascular stenosis and occlusion. This vascular stenosis and occlusion ultimately causes variable signs and symptoms, depending on the territory supplied by the affected vessel. For example, short posterior ciliary artery occlusion results in ischemic optic neuropathy. Interestingly, serum and tissue levels of various inflammatory cytokines (such as interleukin-6) may predict the clinical course and degree of intimal hyperplasia.
Risk Factors[edit | edit source]
GCA occurs most commonly in individuals over the age of 50. Caucasians, especially those of Scandinavian or Northern European descent are most commonly affected  , regardless of their geographic location. The incidence of GCA increases with increasing age,, with average estimates ranging between 2.3 per 100,000 cases per year in the sixth decade to 44.7 per 100,000 cases per year in patients in their ninth decade.The average age of presentation is 72.5 years for women, and 70.3 years old for men. GCA is also more common in women, who are affected more than twice as often than men. Other risk factors may include smoking, low body mass index, early menopause, and relative adrenal hypofunction. Although extremely rare, GCA has been reported in patients younger than 50 years old.
There are several indications that point toward a genetic basis for GCA. For example, familial clustering and monozygotic twin concordance have been reported., Furthermore, associations with human leukocyte antigen (HLA) DRB1*04, DRW6, and DR3 have also been reported. In addition to HLA associations, polymorphisms in several immunomodulating proteins (e.g. tumor necrosis factor- and interleukin 10) have been associated with GCA.
General Pathology[edit | edit source]
GCA is characterized by a nodular granulomatous inflammation of medium- and large-sized arteries. Pathological examination of affected vessels usually reveals a fragmented internal elastic lamina, with a cellular infiltrate extending transmurally. Giant cells are not necessary on the pathologic specimen to confirm the diagnosis; however, when they are present, they are most often situated near the fragmented internal elastic membrane. The most common vessels affected are the superficial temporal artery, the ophthalmic artery, the posterior ciliary arteries, and the vertebral arteries. Less commonly, the aorta, coronary arteries, and carotid circulation are affected; intracranial arteries are typically spared.
Figure 1. Top panel: Pathologic specimen from a patient with biopsy proven giant cell arteritis. Multi-nucleated giant cells (arrow) are present in the vessel wall. Bottom panel: Higher power view.
Photograph courtesy of Ben Glasgow, M.D.
Pathophysiology[edit | edit source]
The most common ocular manifestation of GCA is visual loss, most commonly secondary to AAION.In these cases, the short posterior ciliary arteries are occluded by intimal hyperplasia. Once occluded, the short posterior ciliary arteries cannot provide blood flow to the prelaminar and laminar portions of the optic nerve head, this results in an ischemic injury to the anterior portion of the optic nerve (AAION). Additionally, retinal ischemia can result from co-existent (or isolated) central retinal artery involvement. Ischemia to other ocular structures, such as the extraocular muscles, can result in dysfunction of the affected structure (see “Physical Examination” section).
In addition to the ocular findings described above, patients often complain of headache and scalp tenderness. These symptoms can be attributed to involvement of the temporal artery, and resultant localized ischemia. Jaw claudication, another common symptom of GCA, is due to vascular involvement in the territory of the masticatory muscles. Systemic symptoms such as fevers and malaise are likely secondary to the release of inflammatory cytokines, such as interleukin-6, during the acute inflammatory phase.
Diagnosis[edit | edit source]
The diagnosis of GCA is complicated by the fact that there is no single test that can be used to rule it in or out. Additionally, patients can present with a broad range of symptoms including both systemic and ocular complaints; further complicating the diagnosis is the possibly transient nature of many of the characteristic signs and symptoms. There are several features in the history, physical examination, and in ancillary tests that can aid the clinician in making the diagnosis. However, clinicians must consider each patient on a case-by-case basis as symptoms, examination features, and ancillary test results are analyzed. A high index of suspicion is crucial in any elderly patient with a new onset headache or visual changes.
History[edit | edit source]
The most common ocular manifestation in GCA is acute unilateral vision loss, which has been reported in 7-60% of patients with GCA.32 In approximately 30% of patients with permanent vision loss, there are antecedent episodes of amaurosis fugax. These episodes of transient visual loss typically begin about 8.5 days prior to permanent loss, and are secondary to transient retinal, choroidal, and/or optic nerve ischemia. Typically, the vision loss is secondary to optic nerve ischemia (AAION); it is less commonly due to a central retinal artery occlusion. Other than vision loss, patients may complain of diplopia, eye pain, or symptoms from cranial neuropathies (i.e. ptosis, anisocoria, diplopia).
Systemic symptoms are present in most patients, may be acute or gradual, and often precede the ocular manifestations. The most common systemic complaint of GCA patients is a new onset headache (temporal or occipital), which is present in 90% of cases. Headaches are often associated with localized or diffuse scalp tenderness, and patients may complain of discomfort when combing their hair or placing their head on a pillow. Patients often note a wide range of constitutional symptoms, such as fatigue, fevers, and weight loss. In addition, they may complain of jaw claudication, and pain in other areas including the face, ears, and mouth. Distinct tongue numbness and vertigo have also been reported. Myalgias, especially of the proximal muscles, are also associated with GCA. Less often, neurological symptoms, such as peripheral neuropathies, strokes, scalp necrosis and dementia have all been attributed to GCA.
Symptoms of polymyalgia rheumatica (PMR) are present in up to 50% of patients. PMR is a more common inflammatory syndrome that seems to share a similar underlying etiology with GCA, as well as a similar demographic of commonly affected patients. Symptoms of PMR include bilateral aching neck, shoulder pain or stiffness and pelvic pain or stiffness. Additionally, many patients with PMR note constitutional symptoms such as fever, weight loss, and anorexia.
Physical examination[edit | edit source]
The physical examination of a patient in whom GCA is suspected should include careful evaluation of the following elements:
1. Detailed examination of the temporal artery to detect prominence (Figure 2), nodularity, or tenderness to palpation of the artery and the surrounding skin. In addition, an evaluation of the strength of the temporal artery pulse is crucial.
2. Detailed ophthalmologic examination evaluating visual acuity, pupils (looking for a relative afferent defect), intraocular pressures, anterior segment examination, motility examination (looking for ocular misalignment and/or evidence of cranial neuropathies), and a dilated fundus examination (evaluating for signs of optic nerve or retinal ischemia)
3. Visual fields testing
4. Auscultation of the carotid artery for bruits
5. Auscultation of the heart for an aortic regurgitation murmur to evaluate for aortic aneurysm
Figure 2. Preoperative appearance of a patient with a prominent left superficial temporal artery. The vessel was tender and pulseless. Histopathology confirmed a result positive for temporal arteritis in this case. Image courtesy of Marcus M. Marcet, MD FACS.
AAION is characterized by acute monocular vision loss accompanied by optic disc edema. The optic disc edema in AAION is usually diffusely “chalk white”, and may be accompanied by disc hemorrhage, retinal whitening or cotton wool spots. Adjacent retinal whitening and cotton wool spots are crucial findings that indicate concurrent retinal ischemia, and should raise a clinician’s suspicion for GCA. Visual acuity is often 20/200 or worse, with up to 21% demonstrating no light perception. An obvious afferent pupillary defect is often present. Visual field loss in patients with AAION is typically in a central, arcuate, or altitudinal pattern.
A much less common cause of GCA-associated optic neuropathy is posterior ischemic optic neuropathy. In cases of posterior ischemic optic neuropathy, patients will present with similar symptoms to those with AAION, and will have similarly decreased visual acuity, abnormal visual fields, and a relative afferent pupillary defect. However, in posterior ischemic optic neuropathy, the optic disc will appear perfectly normal; therefore, a high index of suspicion for posterior ischemic optic neuropathy is warranted in elderly patients presenting with acute visual loss and a normal appearing optic nerve.
In addition to the optic nerve circulation, the central retinal artery can also be affected by GCA: approximately 10% of patients with ocular involvement experience a central retinal artery occlusion. Central retinal artery occlusions are manifest by retinal whitening with an associated “cherry red spot” in the macula. If the retinal whitening is more diffuse, and there is absence of a “cherry red spot”, then ophthalmic artery occlusion should be suspected. GCA should be considered in any patient with a central retinal artery occlusion over the age of 50.
Localized ischemia to the extra-ocular muscles and/or cranial nerves can result in diplopia and ocular misalignment in 2-15% of patients. Additionally, Horner’s syndrome50, anterior segment ischemia, and hypotony (likely secondary to decreased aqueous humor production) have all been reported in patients with GCA.
[edit | edit source]
Figure 3. Typical findings of a patient with arteritic ischemic optic neuropathy. Note the pallid disc edema, associated hemorrhages, and adjacent cotton wool spot. Photograph courtesy of Dr. Nicholas Volpe.
Signs[edit | edit source]
Although ocular involvement is common in GCA, the incidence of ocular findings in all GCA patients is not well-defined. In various studies, ocular findings range from 14-70%(this wide range is largely due to differing study populations). The visual loss can initially be transient, and can become bilateral and permanent, with typical involvement of the second eye often within 14 days in untreated cases. In addition, GCA can present with any ocular symptoms (vision loss or diplopia) without additional systemic findings; this type of presentation is considered “occult”, and can occur in up to 38% of cases.
Symptoms[edit | edit source]
Reliability of symptoms
The sensitivity and specificity of many ocular and non-ocular findings have been intensively studied in order to delineate clear indications for further testing. Meta-analyses of several studies have determined that both jaw claudication and diplopia are the most diagnostically powerful indicators of GCA. Furthermore, temporal artery abnormalities such as temporal artery pain and an abnormal temporal artery on palpation are good indicators of disease.
In 1990, the American College of Rheumatology set forth criteria for the diagnosis of GCA. The criteria include the presence of at least 3 of the following 5 findings:
1. Greater than 50 years old
2. New onset of headache
3. Temporal artery abnormality on examination
4. Elevated erythrocyte sedimentation rate (ESR) using the Westergreen method (>50 mm/h)
5. Abnormal arterial biopsy demonstrating a necrotizing vasculitis with predominance of mononuclear cells and granulomatous inflammation.
These criteria have been shown to have a sensitivity of 93.5% and a specificity of 91.2% in diagnosing GCA in patients with vasculitis. However, the importance of the clinical history and setting cannot be understated when diagnosing GCA. Furthermore, these criteria were determined by rheumatologists, and studies that defined them were likely subject to under-representation of patients with solely ocular manifestations. Several criticisms have been raised regarding these criterion, including the lack of specificity of headache, the lack of inclusion of several very significant markers such as CRP, jaw claudication, and neck pain, and the possibility of GCA with a normal ESR or temporal artery biopsy.
Clinical diagnosis[edit | edit source]
The diagnosis of GCA should be considered in any patient over the age of 50 with new headaches, acute visual changes, symptoms of polymyalgia rheumatica, unexplained constitutional symptoms, or jaw claudication. Since individual patients with GCA can present with a wide range of symptoms and examination findings, and many of the symptoms may be transient, patients must be questioned directly about symptoms of GCA. In any patient in whom GCA is suspected based on history, examination findings, or an elevated ESR, a temporal artery biopsy and initiation of corticosteroid treatment should be considered. In addition, several ancillary tests may help to confirm the diagnosis.
Diagnostic procedures[edit | edit source]
Temporal artery biopsy
Unfortunately, there is no single test that is positive in all cases of GCA. Temporal artery biopsy is the gold standard (Figure 4); however, a negative biopsy does not confirm a negative diagnosis. The biopsy should be obtained as soon as possible after the patient’s presentation, but should not delay the initiation of treatment with corticosteroids. Most authors feel that the sensitivity of the biopsy is not significantly affected for the first 2 weeks after starting therapy. However, there has been one study that demonstrated a decrease in sensitivity from 82% to 60% after 1 week of steroid therapy.
False negatives are relatively common (5-13%) because of “skip lesions”, or areas without disease within the vessels.24 In order to avoid false negatives, it is recommended that the biopsy sample have a length of at least 2.5 cm of artery. Sections should be stained with hematoxylin and eosin, as well as a stain for elastin. Most commonly, a panarteritis consisting of lymphocytes and macrophages with or without granuloma formation is seen. Additionally, intimal thickening and fragmentation of the internal elastic lamina should be sought.
The procedure for obtaining a temporal artery biopsy is relatively safe, with rare reports of complications including hematoma, infection, nerve damage, stroke and scalp necrosis. Temporal artery biopsy can also be repeated on the fellow side if the first biopsy is negative and clinical suspicion is high; repeat biopsy may be positive in 1-15% of patients.
Figure 4. Initial intraoperative appearance of a temporal artery biopsy. The ruler along the left side is located posteriorly in this case. The incision is made posterior to the hairline (hair shaved) to avoid damage to the temporalis branch of the facial nerve. The right superficial temporal artery is clearly seen prior to complete dissection and biopsy. Except for grossly visible age-related calcification, the intraoperative appearance of the vessel was otherwise normal. The histopathology confirmed a negative result. Image courtesy of Marcus M. Marcet, MD FACS.
Ancillary imaging tests
Patients with GCA have abnormalities on several ancillary tests. Fluorescein angiography has been found to show delayed choroidal and central retinal artery filling, with possible choroidal non-perfusion, especially in the peri-papillary area.  Angiographic findings are usually seen within the first days of symptom onset.29
Duplex ultrasonography may demonstrate arterial edema, which is represented by hypoechoic halos immediately adjacent to the arterial wall; this finding has been shown to have a sensitivity of 69% and specificity of 82% in a recent meta-analysis. In a single study, the specificity reached 100% when the halos were found bilaterally.
Magnetic resonance imaging (MRI) has recently been utilized in the diagnosis of GCA, but may demonstrate blood vessel wall thickening and/or enhancement (in the same area as the “halo-sign” on ultrasound). Ultrasound biomicroscopy (UBM) has also been used preliminarily to detect the halo sign. Finally, computerized tomography (CT), MRI and PET scanning of the abdomen and chest may be useful to evaluate the aorta and other great vessels if large vessel vasculitis is suspected.
Laboratory tests[edit | edit source]
The most commonly utilized laboratory test in the diagnosis of GCA is the ESR, measured by Westergren method. The ESR can occasionally be normal (ie. <30-40 mm/hr) in up to 30% of patients with biopsy proven GCA.  A meta-analysis of many studies showed that an ESR >100 mm/hr had a positive likelihood ratio (LR) of 2.466 and a negative LR of 0.775. However, the ESR can be normalized by corticosteroids or immunosuppression, and there is often difficulty in decision making when the ESR ranges between 50 and 100. In addition, the ESR may be elevated in other disease states such as anemia, inflammatory disease, malignancy, or infection.Therefore, the ESR must be interpreted within the clinical context of a given scenario.
The C-reactive protein (CRP) has been utilized as an adjunct test to the ESR. The CRP has certain advantages over the ESR, including a lack of variation with age, sex or hematological factors. The sensitivity and specificity of the CRP for the diagnosis of GCA has been reported as 100% and 97%, respectively. Some authors have asserted that the CRP is more sensitive in the diagnosis of GCA. A retrospective chart review of 119 patients with biopsy-proven GCA demonstrated a 99% sensitivity when ESR and CRP were utilized together.
Other markers of GCA include thrombocytosis, anti-cardiolipin antibodies, elevated IFN gamma, and elevated interleukin-6. However, none of these markers have been proven to have definite correlation in large studies, and are thus subjects for future research.
Differential diagnosis[edit | edit source]
The most common disease in the differential diagnosis of GCA with decreased vision is non-arteritic ischemic optic neuropathy (NAION). There are several differences in the patient population, clinical signs and symptoms that are important to elicit. NAION is associated with small-crowded optic nerves, hypertension, diabetes, and hyperlipidemia, whereas AAION patients do not necessarily have the same vascular risk factors. In addition, patients with GCA are typically older than those with NAION (i.e. 8th-9th decade vs. 6th-7th decade). In NAION, patients will usually not note any associated systemic symptoms such as headache, jaw claudication, scalp tenderness, weight loss, anorexia, fever, or myalgias/arthralgias. In general, the vision loss from GCA is more severe than NAION, with one third of the AAION patients demonstrating a visual acuity worse than 20/200, and most NAION patients retaining a visual acuity near 20/80. In addition, AAION patients may complain of preceding amaurosis fugax, as well as other ocular symptoms such as diplopia, fellow eye involvement, or ophthalmoplegia.
The physical examination also differs between these two diseases. Unlike NAION, AAION patients demonstrate a diffuse “chalky” white edema, eventual cupping of the disc, and possible coexistent retinal ischemia. NAION often demonstrates segmental optic nerve edema with eventual sectoral or total flattening and pallor. In addition, laboratory evaluations such as the ESR and CRP are usually normal in patients with NAION.
Aside from NAION, one must consider other systemic causes of vasculitis which may present with similar systemic and possibly ophthalmic manifestations. These conditions include rheumatoid arthritis, systemic lupus erythematosis, polyarteritis nodosa, polymyositis, and Takasayu arteritis. In addition, one should consider malignancy, systemic infections, dental disease, trigeminal neuralgia, and amyloidosis in the appropriate clinical setting.
Management[edit | edit source]
Medical therapy[edit | edit source]
The standard of care for the initial treatment of GCA is corticosteroids. Corticosteroids should be started immediately after patients are suspected of having GCA, and should not be held until a biopsy can be undertaken. There is no standardized regimen for the optimal dose of corticosteroids for either induction or maintenance therapy. It has been shown, however, that higher doses of corticosteroids should be utilized in higher risk patients, ie. those who have had severe vision loss, or those with the potential for severe vision loss or cerebrovascular disease. Suggested dosages of prednisone for initiation of treatment range from 40 mg to 100 mg per day, with a common starting point of 1 mg/kg/day. If the diagnosis of GCA is confirmed with a biopsy, prednisone dosage should be increased to 80-100 mg/day, or intravenous corticosteroids (ie. 1 gram of methylprednisone for 3 days followed by 1-2 mg/kg/day of oral prednisone) should be utilized. Some have suggested that IV steroids be utilized in patients with amaurosis fugax, marked loss of vision in one eye, or signs of fellow eye involvement. There is no consensus regarding the use of IV steroids, since there has not been any significant benefit demonstrated in several studies and the elderly population is at high risk of serious adverse reactions to high dose IV steroid pulses. However, IV methylprednisone has been shown to demonstrate higher serum concentrations more rapidly than oral dosing, and is probabloy useful in certain clinical scenarios.
In select situations, steroid-sparing agents may be utilized. Situations in which the need for these agents may arise include those patients who do not respond to corticosteroids or for those who require less exposure to steroids because of side effects. Methotrexate has been shown to suppress disease activity when used with lower dosages of corticosteroids over a shorter course. Other drugs under investigation include anti-tumor necrosis factor alpha antibody, azathioprine, cyclophosphamide, and anti-platelet agents, such as aspirin.
Medical follow up[edit | edit source]
Once corticosteroid treatment is initiated, it is important to follow the patient closely to determine the response to therapy. Some have recommended following the ESR and CRP from every 3 days to weekly, depending on the severity and route of administration of the corticosteroids.98 Although symptomatic improvement may be reached within days of therapy initiation, the ESR can take several weeks to decrease. Once an effective dose of corticosteroid is reached (based upon improvement in symptoms), the treatment at this dose should be continued for a minimum of 4-6 weeks. However, treatment courses typically last for 1 to 2 years, given the importance of a very slow steroid taper to avoid a relapse of the GCA.
Once the decision is made to taper the corticosteroids, it is usually decreased at a rate of 5-10 mg per month until a dose of 10-15 mg per day is reached, and then the taper is decreased by 1-5 mg per month. The patient should be followed closely for any relapse of symptoms, or increase in ESR or CRP. Relapses typically occur within the first 1.5 years, with a median time of approximately 7 months;106 however, active disease has been reported up to 9 years after initiating therapy.
Complications[edit | edit source]
Patients with known GCA can rarely develop sequelae of large vessel vasculitis, including aortic aneurysms or dissection, after steroid treatment has been tapered. Studies using positron emission tomography (PET) and autopsy suggest that more than 50% of patients with GCA may have subclinical aortitis.Fortunately, the rate of catastrophic events from aortic aneurysms in this population is probably less than 10%. In addition, GCA can affect the coronary arteries, and patients with GCA have an increased relative risk of ischemic cardiovascular events, such as angina or myocardial infarction.
There are several side effects and complications related to the use of long-term corticosteroids. Most commonly, patients are at increased risk for osteoporosis and gastrointestinal disturbances. For this reason, it is recommended that patients on long term corticosteroids should be given calcium, vitamin D supplementation, and an H2 blocker or proton pump inhibitor. Furthermore, one should consider the use of bisphosponates in selected patients. Other complications for which patients must be monitored include diabetes mellitus, hypertension, immunosuppression, glaucoma, and cataracts.
Prognosis[edit | edit source]
The visual prognosis is highly dependent on the rapidity with which steroids are started, and the status of the patient’s vision upon presentation. If the patient has already had an ischemic event resulting in AAION or a CRAO, it is rare that vision will improve appreciably. However, up to one-third of treated cases may demonstrate some small degree of improvement in acuity after treatment has been initiated.
In general, vision often stabilizes once steroids are started; however, if it deteriorates on steroid therapy, it tends to be within 5 days and is rare after 1 month. It has been suggested that 9-17% of patients may have a deterioration of their vision while on corticosteroids. Additionally, one small study suggested that approximately 9% of patients can progress to fellow eye involvement after therapy is initiated; in contrast, 20-62% of untreated patients may progress to this stage. If there is visual deterioration after treatment is initiated, the prognosis is grim, with 80% of patients progressing to light perception or no light perception in one small study. Features that are associated with a worse visual prognosis include visual symptoms before the steroids are initiated, older age, fever, weight loss, antecedent transient visual loss, diplopia, and jaw claudication. In addition, studies have demonstrated a worse ocular prognosis in patients with a high concentration of hemoglobin and a lower ESR.
Patients with GCA may also be at increased risk for cardiovascular disease within the first year of diagnosis, including myocardial infarction from coronary artery vasculitis, aortic disease, and stroke. These patients also may experience complications from long-term steroid use. Finally, it has been suggested that GCA patients are at increased risk for malignancy, which has been observed in 7% of patients. Fortunately, despite all of these potential complications, the life expectancy of this population is not significantly different than that of the general population.
References[edit | edit source]
- Salvarani C, Gabriel SE, O'Fallon WM, Hunder GG. The incidence of giant cell arteritis in Olmsted County, Minnesota: apparent fluctuations in a cyclic pattern. Ann Intern Med 1995;123:192-4.
- Gabriel S, Espy, M, Erdman, DD, Bjornsson, J, Smith, TF, Hunder, GG. The role of parvovirus B19 in the pathogenesis of giant cell arteritis. Arthritis Rheum 1999;42:1255-1258.
- fckLRNordborg C, Nordborg, E, Petursdottir, V, et al. Search for Varicella zoster virus in giant cell arteritis. Ann Neurol 1998;44:413-414.
- fckLRRimeti G, Blasi, F, Cosentini, R, et al. Temporal arteritis associated with Chlamydia pneumoniae DNA detected in an arterial specimen. J Rheumatol 2001;28:1738-1739.fckLR
- Rodriguez-Pla A, Bosch-Gil, JA, Echevarria-Mayo, JE, et al. No detection of parvovirus B19 or herpesvirus DNA in giant cell arteritis. J Clin Virol 2004;31:11-15.
- fckLRRegan M, Wood, BJ, Hsieh, YH, et al. Temporal arteritis and Chlamydia pneumoniae: failure to detect the organism by polymerase chain reaction in ninety cases and ninety controls. Arthritis Rheum 2002;46:1056-60.
- Ma-Krupa W, Kwan M, Goronzy JJ, Weyand CM. Toll-like receptors in giant cell arteritis. Clin Immunol 2005;15:38-46.
- Weyand C, Goronzy, JJ. Pathogenic principles in giant cell arteritis. Int J Cardiol 2000;75:S9-15.
- Carroll S, Gaskin, BJ, Danesh-Meyer, HV. Giant cell arteritis. Clin Experiment Ophthalmol 2006;34:159-173.
- Bengtsson B, Malmvall, BE. The epidemiology of giant cell arteritis including temporal arteritis and polymyalgia rheumatica, incidences of different clinical presentations and eye complications. Arthritis Rheum 1981;24:899-904.
- Fauchald P, Rygvold, O, Oystese, B. Temporal arteritis and polymyalgia
- Machado E, Michet, CJ, Ballard, DJ, et al. Trends in incidence and clinical presentation of temporal arteritis in Olmsted County, Minnesota, 1950-1985. Arthritis Rheum 1988;31:745-749.fckLR
- Nordborg C, Johansson, H, Petursdottir, V, et al. The epidemiology of biopsy-positive giant cell arteritis: special reference to changes in the age of the population. Rheumatology 2003;42:549-552.
- Baldursson O, Steinsson, K, Bjornsson, J, et al. Giant cell arteritis in Iceland. An epidemiologic and histopathologic analysis. Arthritis Rheum 1994;37:1007-1012.fckLR
- Larsson K, Mellstron, D, Nordborg, E, Oden, A, Nordborg, E. Early menopause, low body mass index, and smoking are independent risk factors for developing giant cell arteritis. Ann Rheum Dis 2006;65:529-532.fckLR
- Narvaez J, Bernad, B, Diaz Torne, C, et al. Low serum levels of DHEAS in untreated polymyalgia rheumatica/giant cell arteritis. J Rheumatol 2006;33:1293-1298.fckLR
- Pipinos I, Hopp, R, Edwards, WD, Radio, SJ. Giant-cell temporal arteritis in a 17-year-old male. J Vasc Surg 2006;43:1053-1055.fckLR
- Kemp A. Monozygotic twins with temporal arteritis and ophthalmic arteritis. Acta Ophthalmol 1977;55:183-190.fckLR
- Wernick C, Duvey, M, Bonafede, P. Familial gianct cell arteritis: report of an HLA-typed sibling pair and review of the literature. Clin Exp Rheumatol 1994;12:63-66.fckLR
- Dababneh A, Gonzalez-Gay, MA, Garcia-Porrua, C, et al. Giant cell arteritis and polymyalgia rheumatic can be differentiated by distinct patterns of HLA class II associations. J Rheumatol 1998;25:2140-2145.fckLR
- Calamia K, Moore, SB, Elveback, LR, Hunder, GG. HLA-dR locus antigens in polymyalgia rheumatica and giant cell arteritis. J Rheumatol 1981;8:993-996.fckLR
- Barrier J, Bignon, JD, Soullou, JP, Grolleau, J. Increased prevalence of HLA-DR4 in giant cell arteritis. N Engl J Med 1981;305:104-105.fckLR
- Rahman W, Rahman, FZ. Giant cell (temporal) arteritis: an overview and update. Surv Ophthalmol 2005;50:415-428.fckLR
- Lie J. Histopathologic specificity of systemic vasculitis. Rheum Dis Clin North Am 1995;21:883-909
- Weyand C, Bartley, GB. Giant cell arteritis: new concepts in pathogenesis and implications for management. Am J Ophthalmol 1997;123:392-395.fckLR
- Wilkinson I, Russell, RW. Arteries of the head and neck in giant cell arteritis. Arch Neurol 1972;27:378-391.fckLR
- Hayreh S, Podhajsky, PA, Zimmerman, B. Ocular manifestations of giant cell arteritis. Am J Ophthalmol 1998;125:509-520.fckLR
- Hayreh S. Anterior ischaemic optic neuropathy II. Fundus on ophthalmoscopy and fluorescein angiography. Br J Ophthalmol 1974;58:964-980.fckLR
- Hayreh S, et al. Acute ischemic disorders of the optic nerve: pathogenesis, clinical manifestations, and management. Ophthalmol Clin North Am 1996;9:407-442.fckLR
- Henkind P, Charles, NC, Pearson, J. Histopathology of ischaemic optic neuropathy. Am J Ophthalmol 1970;69:78-90.fckLR
- Weyand C, Goronzy, JJ. Medium and large-vessel vasculitis. N Engl J Med 2003;349:160-169.fckLR
- Kawasaki A, Purvin V. Giant cell arteritis: an updated review. Acta Ophthalmol 2009;87:13-32.
- Cid M, Font, C, Oristrell, J, et al. Association between strong inflammatory response and low risk of developing visual loss and other cranial ischemic complicatios in giant cell (temporal) arteritis. Arthritis Rheum 1998;41:26-32.
- Ghanchi F, Weir, C, Dudgeon, J. Facial swelling in giant cell (temporal) arteritis. Eye 1996;10:747-749.
- Salvarani C, Cantini, F, Boiardi, L, et al. Polymyalgia rheumatica and giant-cell arteritis. N Engl J Med 2002;347:261-271.
- Tovilla-Canales J. Ocular manifestations of giant cell arteritis. Curr Opin Ophthalmol 1998;9:73-79.
- Caselli R, Hunder, GG, Whisnant, JP. Neurologic disease in biopsy-proven giant cell (temporal) arteritis. Neurology 1988;38:352-359.
- Chess J, Albert, DM, Bhan, AK, et al. Serologic and immunopathologic findings in temporal arteritis. Am J Ophthalmol 1983;96:283-289.
- Reich K, Giansiracusa, DF, Strongwater, Sl. Neurologic manifestations of giant cell arteritis. Am J med 1990;89:67-72.
- Sandercock P, Warlow, CP, Jones, LN, et al. Predisposing factors for cerebral infarction: the Oxfordshire community stroke project. BMJ 1989;298:75-80.
- Manetas S, Moutzouris, DA, Falagas, ME. Scalp necrosis: a rare complication of temporal arteritis. Clin Rheumatol 2006;26:1169.
- Caselli R. Giant cell (temporal) arteritis: a treatable cause of multi-infarct dementia. Neurology 1990;40:753-755.
- Paulley J, Hughes, JP. Giant cell arteritis or arthritis of the aged. BMJ 1960;2:1562-1567.
- Healey L. The relation of giant cell arteritis to polymyalgia rheumatica. Baillieres Clin Rheumatol 199;5:371-378.
- Liu G, Glaser, JS, Schatz, NJ, Smith, JL. Visual morbidity in giant cell arteritis. Clinical characteristics and prognosis of vision. Ophthalmology 1994;101:1779-1785.
- Danesh-Meyer H, Savino, PJ, Gamble, GD. Poor prognosis of visual outcome after visual loss from giant cell arteritis. Ophthalmology 2005;112:1098-1103.
- Huston K, Hunder, GG, Lie, JT, et al. Temporal artertitis: a 25-year epidemiologic, clinical, and patholgic study. Ann Intern Med 1978;88:162-167.
- Meadows S. Temporal or giant cell arteritis. Proc R Soc Med 1966;85:251-258.
- McKillop E, Tejawani, D, Weir, C, Jay, J. Anterior segment ischaemia with giant cell arteritis. Can J Ophthalmol 2006;41:201-203.
- Calcagni A, Claes, CA, Maheshwari, M, Jacks, AS. Hypotony as a presentation of giant cell arteritis. Eye 2007;21:123-4.
- Graham E, Holland, A, Avery, A, et al. Prognosis in giant-cell arteritis. Br Med J 1981;282:269-271.
- Jonasson F, Cullen, JF, Elton, RA. Temporal arteritis: a 14-year epidemiological clinical and prognostic study. Scott Med J 1979;24:111-117.
- Whitfield A, Bateman, M, Trevor Cooke, W. Temporal arteritis. Br J Ophthalmol 1963;47:555-566.
- Cornblath W, Eggenberger, ER. Progressive visual loss from giant cell arteriits despite high-dose intravenous methylprednisonolone Ophthalmology 1997;104:854-858.
- Niederkohr R, Levin, LA. Management of the patient with suspected temporal arteritis. A decision-analytic approach. Ophthalmology 2005;112:744-756.
- Smetana G, Shmerling, RH. Does this patient have temporal arteritis. JAMA 2002;287:92-101.
- Hunder G, Bloch, DA, Michel, BA. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis Rheum 1990;33:1122-1128.
- Hayreh S, Podhajsky, P, Raman, R, Zimmerman, B. Giant cell arteritis: validity and reliability of various diagnositic criteria. Am J Ophthalmol 1997;123:285-296.
- Hayreh S, Zimmerman, B. Management of giant cell arteritis. Our 27-year clinical study: new light on old controversies. Ophthalmologica 2003;217:239-259.
- Achkar A, Lie, JT, Hunder, GG, et al. How does previous corticosteroid treatment affect the biopsy findings in giant cell (temporal) arteritis. Ann Intern Med 1994;120:987-992.
- Allison M, Gallagher, PJ. Temporal artery biopsy and corticosteroid treatment. Ann Rheum Dis 1984;1984:416-417.
- Bhatti M, Goldstein, MH. Facial nerve injury following superficial temporal artery biopsy. Dermatol Surg 2001;27:15-17.
- Stuart R. Temporal artery biopsy in suspected temporal arteritis: a five-year survey. N Z Med J 1989;102:431-433.
- Mizen T, et al. Giant cell arteritis: diagnostic and therapeutic considerations. Ophtahl Clin North Am 1991;4:547-556.
- Danesh-Meyer H, Savino, PJ, Eagle, RC, Kubis, KC, Sergott, RC. Low diagnostic yield with second biopsies in suspected giant cell arteritis. J Neuroophthalmol 2000;20:213-215.
- Hall S, Hunder, GG. Is temporal artery biopsy prudent? Mayo Clin Proc 1984;59:793-796.
- Klein R, Campbell, RJ, Hunder, GG. Skip lesions in temporal arteritis. Mayo Clin Proc 1976;51:504-510.
- Ponge T, Barrier, JH, Grolleau, JY, Ponge, A, Vlasak, AM, Cottin, S. The efficacy of selective unilateral temporal artery biopsy versus bilateral biopsies for diagnosis of giant cell arteritis. J Rheumatol 1988;15:997-1000.
- Hall J, Volpe, NJ, Galetta, SL, et al. The role of unilateral temporal artery biopsy. Ophthalmology 2003;110:543-548.
- Siatkowski R, Gass, DM, Glaser, JS, Smith, JL, Schartz, NJ, Schiffman, J. Fluorescein angiography in the diagnosis of giant cell arteritis. Am J Ophthalmol 1993;115:57-63.
- Ghanchi F, Williamson, TH, Lim, CS, et al. Colour doppler imaging in giant cell (temporal) arteritis: serial examination and comparison with non-arteritic anterior ischaemic optic neuropathy. Eye 1996;10:459-464.
- Hunder G, Weyand, CM. Sonography in giant cell arteritis. N Engl J Med 1997;337:1385-1386.
- Schmidt W, Kraft, HE, Vorpahl, K, Volker, L, Gromnica-Ihle, EJ. Color duplex ultrasonography in the diagnosis of temporal arteritis. N Engl J Med 1997;337:1336-1342.
- Karassa F, Matsaga, MI, Schmidt, WA, Ioanndis, JP. Meta-analysis: test performance of ultrasonography for giant-cell arteritis. Ann Intern Med 2005;142:359-369.
- Karahaliou M, Vaiopoulos, G, Papaspyrou, S, Kanakis, MA, Revenas, K, Sfikakis, PP. Colour duplex sonography of temporal arteries before decision for biopsy: a prospective study in 55 patients with suspected giant cell arteritis. Arthritis Res Ther 2006;8:R116.
- Bley TW, O, Uhl,M, Thiel, J, Schmidt, D, Langer, M. High-resolution MRI in giant cell arteries: imaging of the wall of the superficial temporal artery. Am J Roentgenol 2005;184:283-287.
- Vianna R, Mansour, M, Ozdal, PC, et al. The role of ultrasound biomicroscopy in predicting the result of temporal artery biopsy in temporal arteritis patients: a preliminary study. Eur J Ophthalmol 2005;15:655-659.
- Hazleman B. Laboratory investigations useful in the evaluation of polymyalgia rheumatica (PMR) and giant cell arteritis. Clin Exp Rheumatol 2001;18:S29-31.
- Ellis M, Ralston, S. ESR in the diagnosis and management of polymyalgia rheumatica/giant cell arteritis syndrome. Ann Rheum Dis 1983;42:168-170.
- Kyle V, Causton, TE, Hazleman, BL. Erythrocyte sedimentation rate and C reactive protein in the assessment of polymyalgia rheumatica/giant cell arteritis on presentation and during follow up. Ann Rheum Dis 1989;48:667-671.
- Salvarni C, Hunder, GG. Giant cell arteritis with low erythrocyte sedimentation rate: frequency of occurence in a population-based study. Arthritis Rheum 2001;45:140-145.
- Parikh M, Miller, NR, Lee, AG, et al. Prevalence of a normal C-reactive protein with an elevated erythrocyte sedimentation rate in biopsy-proven giant cell arteritis. Ophthalmology 2006;113:1842-1845.
- Gonzalez-Alegre P, Ruiz-Lopez, AD, Abara-Costalago, M, et al. Increment of the platelet count in temporal arteritis: response to therapy and ischemic complications. Eur Neurol 2001;45:43-45.
- Bhatti M, Tabandeh, H. Giant cell arteritis: diagnosis and management. Curr Opin Ophthalmol 2001;12:393-399.
- Weyand C, Tetzlaff, N, Bjornsson, J, et al. Disease patterns and tissue cytokine profiles in giant cell arteritis. Arthritis Rheum 1997;40:19-26.
- Hernandez-Rodriguez J, Segarra, M, Vilardell, C, et al. Elevated production of interleukin-6 is associated with a lower incidence of disease-related ischemic events in patients with giant-cell arteritis: angiogenic activity of interleukin-6 as a potential protective mechanism. Circulation 2003;107:2428-2434.
- Danesh-Meyer H, Savino, PJ, Eagle, RC, Sergott, RC. The prevalence of cupping in end-stage arteritic and nonarteritic anterior ischemic optic neuropathy. Ophthalmology 2001;108:593-598.
- Chevalet P, Barrier, JH, Pottier, P, et al. A randomized, multicenter, controlled trial using intravenous pulses of methylprenisolone in the initial treament of simple forms of giant cell arteritis: a one year followup study of 164 patients. J Rheumatol 2000;27:1484-1491.
- Hayreh S, Zimmerman, B, Kardon, RH. Visual improvement with corticosteroid therapy in giant cell arteritis. Report of a large study and review of the literature. Acta Ophthalmol Scand 2002;80:355-367.
- Hayreh S, Zimmerman, B. Visual deterioration in giant cell arteritis patients while on high doses of corticosteroid therapy. Ophthalmology 2003;110:1204-1215.
- Hayball P, Cosh, DG, Ahern, MJ, Schultz, DW, Roberts-Thomson, PJ. High-dose oral methylprednisolone in patients with rheumatoid arthritis: pharmokinetics and clinical response. Eur J Clin Pharmacol 1992;42:85-88.
- Caporali R, Cimmino, MA, Ferraccioli, GF, et al. Prednisone plus methotrexate for polymyalgia rheumatica. Ann Intern Med 2004;141:495-501.
- Jover J, Hernandez-Garcia, C, Morado, IC, et al. Combined treatment of giant-cell arteritis with methotrexate and prednisolone, a randomized, double-blind, placebo-controlled trial. Ann Intern Med 2001;134:106-114.
- Airo P, Antoniolo, CM, Vianelli, M, Toniati, P. Anti-tumour necrosis factor treament with infliximab in a case of giant cell arteritis resistant to steroid and immunosuppressive drugs. Rheumatology 2002;41:347-349.
- De Silva M, Hazleman, BL. Azathioprine in giant cell arteritis/polymyalgia rheumatica: a double blind study. Ann Rheum Dis 1986;45:136-138.
- De Vita S, Tavoni, A, Jeracitano, G, et al. Treatment of giant cell arteritis with cyclophosphamide pulses. J Intern Med 1992;232:373-375.
- Nesher G, Berkun, Y, Mates, M, Baras, M, Rubinow, A, Sonnenblick, M. Low-dose aspirin and prevention of cranial ischemic complications of giant cell artertis. Arthritis Rheum 2004;50:1332-1337.
- Provon A, Gabriel, SE, Orces, C, O'Fallon, WM, Hunder, GG. Glucocorticoid therapy in giant cell arteritis:duration and treament outcomes. Arthritis Rheum 2003;49:703-708.
- Goodman BJ. Temporal arteritis. Am J Med 1979;67:839-852.
- Blumberg S, Giansiracusa, DF, Docken, WP, et al. Recurrence of temporal arteriis. Clinical recurrence nine years after initial illness. JAMA 1980;244:1713.
- Ostberg G. Temporal arteritis in a large necropsy series. Ann Rheum Dis 1971;30:224-235.
- Blockmans D, de Ceunnick L, Vanderscheuren S, Knockaert D, Mortelmans L, Bobbaers H. Repetitive 18F-fluoro-deoxyglucose positron emission tomography in giant cell arteritis: a prospective study of 35 patients. Arthritis Rheum 2006;55:131-7.
- Levine SM, Hellman DB. Giant cell arteritis. Curr Opin Rheumatol 2002;14:3-10.
- Gonzalez-Gay MA, Garcia-Porrua C, Pineiro A, Pego-Reigosa A, Llorca J, Hunder GG. Aortic aneurysm and dissection in biopsy-proven giant cell arteritis patients from Northwest Spain. A population-based study. Medicine 2004;83:335-41.
- Le Page L, Duhaut P, Seydoux D. Incidence of cardiovascular events in giant cell arteritis: preliminary results of a prospective double cohort study. Rev Med Intern 2005;27:98-105.
- Hayreh S. Ophthalmic features of giant cell arteritis. Baillieres Clin Rheumatol 1991;5:431-459.
- Chan C, Pain, M, O'Day, J. Steroid management in giant cell arteritis. Br J Ophthalmol 2001;85:1061-1064.
- Foroozan R, Deramo, VA, Buono, LM, et al. Recovery of visual function in patients with biopsy-proven giant cell arteritis. Ophthalmology 2003;110:539-542.
- Aiello P, Trautmann, JC, McPhee, TJ, et al. Visual prognosis in giant cell arteritis. Ophthalmology 1993;100:550-555.
- Calamia K, Hunder, GG, et al. Clnical manifestations of giant-cell (temporal) arteritis. Clin Rheum Dis 1980;6:389-403.
- Uddhammar A, Eriksson, Al, Nystrom, L, et al. Increased mortality due to cardiovascular disease in patients with giant cell arteritis in northern Sweden. J Rheumatol 2002;29:737-742.
- Morris C, Scheib, JS. Fatal myocardial infarction resulting from coronary arteritis in a patient with polymyalgia rheumatica and biopsy-proven temporal artertis. A case report and review of the literature. Arch Intern Med 1994;154:1158-1160.
- Evans J, O'Fallon, WM, Hunder, GG. Increased incidence of aortic aneurysm and dissection in giant cell (Temporal)artertiis - a population based study. Ann Intern Med 1995;122:502-507.
- Nesher G, Sonnenblick, M, Friedlander, Y. Analysis of steroid related complications and mortality in temporal arteritis: a 15-year survey of 43 patients. J Rheumatol 1994;21:1283-1286.
- Liozon E, Loustaud, V, Fauchais, AL, et al. Concurrent temporal (giant cell) arteritis and malignancy: report of 20 patients with review of the literature. J Rheumatol 2006;33:1606-1614.
- Matteson E, Gold, KN, Bloch, DA, et al. Long-term survival of patients with giant cell arteritis in the American College of Rheumatology giant cell arteritis classification criteria cohort. Am J Med 1996;100:193-196.
- Nordborg E, Bengtsson, BA. Death rates and causes of death in 284 consecutive patients with giant cell arteritis confirmed by biopsy. BMJ 1989;299:549=550.