Date Published: March 29, 2019
Publisher: Public Library of Science
Author(s): Evripidis Kaltsonoudis, Eleftherios Pelechas, Alexandra Papoudou-Bai, Theodora E. Markatseli, Moses Elisaf, Paraskevi V. Voulgari, Alexandros A. Drosos, Wisit Cheungpasitporn.
Temporal artery biopsy (TAB) is useful in assisting with giant cell arteritis (GCA) diagnosis but lacks sensitivity. The aim of our study was to assess the diagnostic impact of TAB histology in patients with suspected GCA on hospital admission.
A prospectively maintained database was queried for all TABs performed between 1-1-2000 until 31-12-2017 at the University Hospital of Ioannina. Thus, inclusion criteria were made on the grounds of every patient that underwent a TAB during the above-mentioned period, regardless of demographic, clinical and laboratory data.
Two hundred forty-five TABs were included (149 females and 96 males), with a mean age of 64.5 (±3.5) years. The mean symptoms duration until admission to the hospital was 8.6 (±1.3) weeks and all had elevated acute phase reactants on admission. The reasons of admission were fever of unknown origin (FUO) in 114 (46.5%) patients, symptoms of polymyalgia rheumatica (PMR) in 84 (34.3%), new headache in 33 (13.5%), anemia of chronic disease (ACD) in 8 (3.32%) and eye disturbances in 6 (2.5%) patients. Positive results were found in 49 (20%) TABs. More specifically, in 14% of patients with FUO, 21% in those with PMR, while in patients with a new headache the percentage was 27%. Finally, 5 out of 6 (83.3%) of patients with ocular symptoms and only one (12.5%) of those suffering from ACD. Visual manifestations and FUO are correlated with a positive TAB.
It seems that TAB is useful in assisting with GCA diagnosis, but lacks sensitivity.
Giant cell arteritis (GCA), also referred to as cranial arteritis, temporal arteritis or Horton’s disease is a type of systemic inflammatory vasculitis of unknown etiology. It is the commonest form of vasculitis in the elderly , which, if left untreated, may cause blindness  and stroke . Even if it is classified as a large-vessel vasculitis (LVV), after the 2012 revised International Chapel Hill Consensus Conference, medium and small arteries are also involved . Typically, it affects the superficial temporal arteries (hence the term temporal arteritis), the ophthalmic, occipital and vertebral arteries but also the aorta, carotid and subclavian arteries. The inflammation leads to vessel functional impairment (stenoses), and as a consequence, to diminished tissue blood supply. Subsequently, irreversible damage may develop affecting mainly the eyes and the central nervous system. It is more prevalent in people over the age of 50 .
A prospectively maintained database was queried for all TABs performed between 1-1-2000 until 31-12-2017 at the University Hospital of Ioannina. All patients’ records were analyzed for demographic, clinical and laboratory data undergoing a TAB, during the period of January 2000 to December 2017. Inclusion criteria were: any patient regardless of demographic, clinical and laboratory data undergoing a TAB during the above-mentioned period. All TABs were carried out prior to steroid therapy. TABs were performed in all suspected GCA patients without any imaging screening prior to biopsy, since imaging expertise for LVV was not available in our hospital. Thus, the very known and relatively common limitation of TAB could not be improved by imaging techniques. This is due to the fact that GCA affects vessels focally and segmentally yielding areas of inflammatory vasculitis lesions juxtaposed with areas of normal arteries. This means that histological signs of inflammation may be missed in TABs performed in arteritis-free segments. As a consequence, 10–20% of TABs are reported to be negative in patients with high suspicion of GCA. Another limitation is the length of the biopsy specimen and the expertise of the pathologist. The mean length of the biopsy specimen was approximately 4 cm, unilateral, but in high-suspicion patients, a bilateral TAB bad been performed. In our hospital, both the surgeon and the pathologist are experience in TAB biopsies. Statistical analysis was performed using SPSS Statistics, version 20.0. A written informed consent form has been obtained by all patients and the study has been approved by the Clinical Research Ethics Committee of the University Hospital of Ioannina according to the principles in the Declaration of Helsinki.
Two hundred forty-five TABs were included. There were 149 females and 96 males with a mean age of 64.5 (±3.5) years, who underwent TABs. The mean symptoms duration until admission to the hospital was 8.6 (±1.3) weeks and all had elevated erythrocyte sedimentation rate (ESR) or/and C-reactive protein (CRP). “Fig 1” shows that from 245 TABs, positive results were found in 49 (20%). Twelve biopsy samples were insufficient to confirm or refute GCA diagnosis, whereas in some patients with high suspicion of GCA, TAB was done bilaterally. This figure depicts also the departments ordered the TABs, as well as the clinical features at admission and the positive TAB histology achieved by each clinic. Positive TABs ranged from zero, ordered by the orthopedic clinic to 83.3% ordered by the eye clinic. The rheumatology clinic achieved positive TABs in 23% of the cases and the department of internal medicine 19%. Finally, 8.3% positive TABs achieved by the neurology clinic. The demographic, clinical, laboratory and histological data are presented in the Table 1. In Table 2 we present the ACR1990 criteria applied to our patients. Half of the patients were admitted due to FUO. In this group positive TABs were demonstrated in 14%. One third of patients was admitted with symptoms of PMR. In these patients positive TABs were found in 21%, while in patients with new headache positive TABs were demonstrated in 27%. Finally, 5 out of 6 (83.3%) of patients admitted with ocular symptoms had positive TABs and only 1 (12.5%) from patients suffering from ACD had positive TAB. Table 3 shows that visual manifestations and FUO are correlated with positive TAB.
Currently there is no 100% accurate test for GCA. The role of TAB in patients suspected as having GCA is still in debate . The European League Against Rheumatism (EULAR) points out the importance of imaging as a first test for the diagnosis in LVV . However, even if imaging is important it doesn’t have to be misinterpreted as a recommendation that can substitute TABs. TAB still has its place when a diagnostic doubt after the application of imaging techniques exists, but also when the recommended imaging modalities are not available or even when there is no sufficient experience by the operator . Elderly patients usually have a new-onset headache and scalp tenderness, typically with an abnormal laboratory test, usually high ESR. Applying the ACR criteria for GCA, these patients are classified as having temporal arteritis. However, it can be difficult to distinguish non-serious forms of headache from GCA. Infections produce similar clinical signs and abnormal laboratory tests. If there is a strong suspicion of GCA, treatment with steroids should be initiated immediately. To confirm the diagnosis, the patient should undergo a biopsy of the temporal artery. On the other hand, biopsy of the temporal artery for the diagnosis of GCA has a relatively low yield . The difficulty in diagnosing GCA, is the lack of a high-quality gold standard test. Although biopsy is reported to be the current gold standard test for its diagnosis, the majority of patients in whom a diagnosis of GCA in suspected do not actually have a positive result . This may reflect the fact that there is a higher index of suspicion for diagnosis and therefore more patients with headache are being evaluated for GCA. Equally, it may reflect the relatively poor association between the true multi-vessel disease of GCA and the TAB findings to support a diagnosis of GCA.