Abstract
Objective
Giant cell arteritis (GCA) is the most common systemic vasculitis in individuals aged ≥50 years. Some patients with GCA who develop fever at onset without typical ischemic manifestations may be misdiagnosed with fever of unknown origin.
Methods
In the present study, we retrospectively evaluated the clinical records of patients with GCA. Patients with and without fever at onset were compared.
Results
This study included 91 patients with GCA, 55 of whom had fever at onset. The patients with fever at onset showed a lower frequency of jaw claudication and arthralgia and a higher percentage of constitutional symptoms than patients without fever. Additionally, their laboratory results revealed a lower percentage of positive anti-neutrophil cytoplasmic antibody. Furthermore, a lower proportion of affected intracranial vessels was found in patients with fever at onset. Finally, the proportion of biopsy-positive cases was higher in patients with than without fever at onset.
Conclusions
In this study, 60.4% of patients with GCA had fever at onset. Patients in this group usually had more severe inflammation with a potentially lower risk of ischemic accidents of the central nervous system than patients without fever at onset.
Keywords
Introduction
Giant cell arteritis (GCA) is the most common systemic vasculitis affecting medium and large vessels in individuals aged ≥50 years. 1 The clinical features of GCA are largely dependent upon the topography of the arteritis, which is often symmetric in paired arteries. 2 A diagnosis of GCA is usually suggested by the classic presentation with ischemic manifestations of cranial vessels and other great vessels, including the aorta and its branches. However, a variable proportion of patients also develop systemic symptoms such as fever, malaise, fatigue, and weight loss. Moreover, some patients are even diagnosed with fever of unknown origin. 3 Thus, diagnosis of GCA in patients with atypical clinical features is challenging. This requires clinicians to establish the proportion of patients with GCA who present with fever at onset. Clinicians must also elucidate the patients’ clinical features, including the affected vessels, laboratory tests, and prognosis of GCA with or without fever at onset.
In the present study, we retrospectively analyzed a cohort of patients with GCA at Peking Union Medical College Hospital, Beijing, China to address the above-described issues.
Materials and methods
Patients
Patients who were preliminarily diagnosed with GCA at Peking Union Medical College Hospital, Beijing, China from November 1998 to October 2017 were enrolled. All patients fulfilled the 1990 American College of Rheumatology diagnostic criteria for GCA. 4 All patients were followed up for the evaluation of clinical outcomes.
Clinical data collection
The patients’ clinical characteristics, including signs and symptoms, laboratory findings, and angiographic findings at the time of diagnosis, were obtained from the medical records and retrospectively evaluated. Central nervous system (CNS) symptoms included vertigo, transient ischemic attack (TIA), and stroke, which were confirmed by neurologists. Comorbid diseases assessed in this study included arteriosclerosis, smoking, diabetes, coronary artery disease, cerebrovascular disease, hypertension, and dyslipidemia. Fever was defined as an axillary temperature of ≥37.3°C, while fever at onset was defined as fever as the first symptom.
The vascular evaluation involved a review of radiologic data obtained from digital subtraction angiography, ultrasonography, computed tomography angiography, magnetic resonance angiography, and positron emission tomography.
During follow-up, the patients’ clinical signs, symptoms, and laboratory results were also evaluated. Patients who underwent therapy and showed gradual tapering of the disease severity without recurrence were considered stable. In contrast, patients who underwent therapy and showed tapering of the disease with recurrence of GCA or with comorbid infections were considered unstable.
Statistical analysis
Continuous variables are presented as mean and standard deviation, and categorical variables are presented as absolute frequency and percentage. Patients with GCA were divided into two groups according to the onset of fever. The two groups were compared using Student’s t-test for continuous variables. The chi-squared test was performed to compare categorical variables. All statistical tests were two-sided, and p-values of <0.05 were considered statistically significant. All data analyses were conducted using SPSS 20.0 software (IBM Corp., Armonk, NY, USA).
Ethical approval
This study was approved by the Ethics Board of Peking Union Medical College Hospital (ethics approval number S-K437), and informed consent was obtained from all patients.
Results
Clinical features and comorbid diseases of patients with GCA with and without fever at onset.
Data are presented as mean ± standard deviation or n (%).
CNS symptoms: vertigo, transient ischemia attack, stroke; GI involvement: abdominal pain, abdominal distention; Constitutional symptoms: fatigue, night sweats, anorexia.
CNS, central nervous system; GCA, giant cell arteritis; GI, gastrointestinal; PMR, polymyalgia rheumatica.
*Statistically significant difference.
Laboratory findings of patients with GCA according to fever onset.
*Statistically significant difference.
ALB, albumin; ANA, anti-nuclear antibody; ANCA, anti-neutrophil cytoplasmic antibody; APS, anti-phospholipid antibody; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; GCA, giant cell arteritis; HGB, hemoglobin; IgG, immunoglobulin G; LYM, lymphocyte; MONO, monocyte; PLT, platelet; SD, standard deviation; WBC, white blood cell.
Artery distribution and biopsy results of patients with GCA according to fever onset.
Statistically significant difference.
GCA, giant cell arteritis.
Follow-up results of GCA patients according to fever onset.
GCA, giant cell arteritis.
Discussion
The average age at the time of GCA onset is reportedly about 76.7 years, 5 which is higher than that of our patients. Additionally, previous research has demonstrated that women are two to three times more commonly affected 6 ; in the present study, however, the proportion of female patients was about 50%. These differences in average age and sex between our study and others may be due to the small sample size of the present retrospective study, although our sample size is the largest in Chinese research to date. In this study, fever at onset was observed in 60.4% of the patients with GCA. This frequency seems to be consistent with that reported in previous case series. Liozon et al. 7 reported that 55% of 175 patients with biopsy-proven GCA had fever. Bengtsson and Malmvall 8 found that 64.2% (61/95) of patients with GCA reported morning temperatures ranging from 38.1°C to 39°C. However, Gonzalez-Gay et al. 9 reported that fever was observed in only 10% of the patients with biopsy-proven GCA, which is much lower than that observed in the current study. These differences among the studies might be attributed to the different definitions of fever and different samples selected from among patients with GCA. These results should be interpreted with caution because our definition of fever differs from that in previous reports; additionally, the present study focused on fever as the initial symptom.7–9
The relationship between fever and the risk of developing ischemic manifestations of GCA is controversial. Patients with strong inflammatory responses manifested by a high ESR, anemia, a low albumin level, and fever reportedly have a low risk of developing severe cranial ischemic complications. 10 Several other studies have partially supported the conclusion that low inflammatory responses are associated with a high risk of developing irreversible cranial ischemic complications (ICIC).9,11 However, another study did not demonstrate an association between the inflammatory response and the risk of developing ICIC. The current study confirmed that patients with fever at onset had a low risk of developing ischemic events, including CNS symptoms and jaw claudication; this partially supports the conclusions by Cid et al. 10
The mechanisms underlying the robust inflammatory responses of patients with GCA exhibiting a low risk of ICIC remain unknown. These mechanisms could involve inflammation-induced angiogenic activity in patients with strong inflammatory responses that play a compensatory role in ischemic complications. 12
Patients with GCA with fever at onset showed high levels of inflammatory markers, including the ESR, C-reactive protein level, platelet count, lower albumin, and anemia, as well as a high frequency of constitutional symptoms. Although some differences were not statistically significant, the results are compatible with the common clinical features of fever.
With respect to the vasculature pattern, GCA is characterized by subacute granulomatous inflammation of the aorta and its major branches with particular tropism for the extracranial carotid artery branches in patients >50 years of age. 13 The pattern of arterial involvement in 12 autopsy cases demonstrated that the presence of arterial segments showing significant elastic tissue in the media and external elastic lamina was correlated with increased artery involvement. 14 Therefore, the cerebrovascular ischemic events in patients with GCA have been reported to be caused by involvement of extradural vertebral and carotid arteries with high-grade stenosis or occlusions, wherein the elastic fibers are more abundant than those in the intracranial arteries. 15 Because of the limited sample size in the present study, we were unable to evaluate subgroups of different intracranial arteries such as the anterior cerebral artery, middle cerebral artery, posterior cerebral artery, vertebral artery, and basilar artery.
About 3% to 4% of patients with GCA reportedly develop cerebrovascular ischemic events. 16 In the present study, 23.1% (21/91) of the patients with GCA showed CNS involvement, which is quite higher than that reported previously. This discrepancy could be attributed to the broad definition of CNS involvement, which included vertigo, TIA, and ischemic stroke from the onset of the disease to GCA diagnosis. Because of the limited sample size, we could not establish subgroups for these three symptoms. Another possibility is that some vessels’ involvement was evaluated by ultrasound in addition to magnetic resonance angiography with contrast or positron emission tomography–computed tomography because it is difficult to differentiate vasculitis from atherosclerosis. The European League Against Rheumatism has recommended imaging techniques for diagnosis and evaluation of large vessel vasculitis in clinical practice, while the recommendation also demonstrated that biopsy could not be replaced by imaging tests because none of the techniques was 100% sensitive.17,18 Another study demonstrated the importance of temporal artery biopsy as the standard test for most patients suspected to have GCA, although it lacked sensitivity. 19 Therefore, the evaluation and diagnosis of GCA contains comprehensive advice and is not limited to a certain imaging test or to temporal artery biopsy.
The present study also demonstrated a significantly lower percentage of intracranial vessel involvement in patients with fever at onset, which is in agreement with the low proportion of cranial ischemic complications. This result reconfirms the conclusion that patients with GCA who develop strong inflammatory responses may have a low risk of ischemic events. 10 Other evaluations of the vessels did not demonstrate a significant difference between the groups because of the small sample size. Hence, a large prospective study is required to evaluate the vessel distribution of GCA.
Another result that requires consideration is the significantly low percentage of ANCA positivity in patients with fever at onset. The association of ANCA with GCA remains obscure despite several published studies.20–23 ANCA is speculated to play a key role in the pathogenesis in a specific group of patients with small- and medium-sized vessel vasculitis. Small vessel vasculitis (SVV) and vasa vasorum vasculitis partially constitute the histopathological spectrum of GCA.24,25 Compared with classic GCA, patients with GCA characterized by SVV show several distinct clinical features including less frequent cranial manifestations, a less severe inflammatory response, and a high frequency of musculoskeletal manifestations. 25 In the present study, patients without fever at onset manifested less severe inflammatory responses and a high frequency of arthralgia, which might be due to the underlying SVV. However, the pathology of the temporal arteries in both groups of patients has not yet been reevaluated to confirm the hypothesis.
This study has several advantages. In China, the prevalence of GCA is often underestimated, and some physicians lack the experience necessary to diagnose GCA. To the best of our knowledge, this is the largest single-center study in the English language from mainland China. Additionally, this study addressed the novel aspect of fever at onset in patients with GCA, which is essential for clinicians.
Nevertheless, the current study has several limitations, including its retrospective design, small sample size, and incomplete dataset, which might have biased the findings. Therefore, caution is necessary when interpreting the results.
In conclusion, 60.4% of the patients with GCA in the present study had fever at onset, and such patients usually had more severe inflammation and a lower risk of ischemic events involving the CNS than those without fever at onset. Clinicians should be aware of the clinical features of these patients and consider the diagnosis of GCA despite the absence of typical ischemic manifestations. The relationship between fever and the risk of ICIC remains unknown, and additional studies are essential to elucidate this relationship. The vascular distribution of GCA with fever at onset was not well demonstrated, and a large-sample study is imperative.
Footnotes
Acknowledgements and authors’ contributions
We thank all the physicians from the Department of General Internal Medicine of Peking Union Medical College Hospital who participated in the care of the patients in this study. YZ and DW drafted the manuscript and carried out the data analysis. YY collected the clinical data and followed up all the patients. HF and WZ participated in the study design. XZ is accountable for the conception and execution of the study. All authors read and approved the final manuscript.
Declaration of conflicting interest
The authors declare that there is no conflict of interest.
Funding
This work was funded by the Basic Research Project of Peking Union Medical College (2018PT310017).
