Patterns of Arterial Disease in Takayasu Arteritis and Giant Cell Arteritis

Abstract

Objective. To identify and validate, using computer-driven methods, patterns of arterial disease in Takayasu arteritis (TAK) and giant cell arteritis (GCA). Methods. Patients with TAK or GCA were studied from the Diagnostic and Classification Criteria for Vasculitis (DCVAS) cohort and a combined North American cohort. Case inclusion required evidence of large-vessel involvement, defined as stenosis, occlusion, or aneurysm by angiography/ultrasonography, or increased 18 F-fluorodeoxyglucose (FDG) uptake by positron emission tomography (PET) in at least 1 of 11 specified arterial territories. K-means cluster analysis identified groups of patients based on the pattern of arterial involvement. Cluster groups were identified in the DCVAS cohort and independently validated in the North American cohort. Results. A total of 1,068 patients were included (DCVAS cohort: TAK = 461, GCA = 217; North American cohort: TAK = 225, GCA = 165). Six distinct clusters of patients were identified in DCVAS and validated in the North American cohort. Patients with TAK were more likely to have disease in the abdominal vasculature, bilateral disease of the subclavian and carotid arteries, or focal disease limited to the left subclavian artery than GCA (P < 0.01). Patients with GCA were more likely to have diffuse disease, involvement of bilateral axillary/subclavian arteries, or minimal disease without a definable pattern than TAK (P < 0.01). Patients with TAK were more likely to have damage by angiography, and patients with GCA were more likely to have arterial FDG uptake by PET without associated vascular damage. Conclusion. Arterial patterns of disease highlight both shared and divergent vascular patterns between TAK and GCA and should be incorporated into classification criteria for large-vessel vasculitis.

The importance of FDG PET/CT in the diagnostic process of the middle aortic syndrome in a 15-year-old boy patient with suspected systemic vasculitis and final diagnosis of Williams–Beuren syndrome

“…The importance of FDG PET/CTA for the diagnosis of Takayasu arteritis has been proven in several newly published studies [30][31][32][33][34], but rare for childhood-onset disease [5,[18][19][20] (Table 1). FDG PET/CTA might be particularly valuable in patients with unspecific symptoms to detect alternative causes of systemic vasculopathy [16].…”

Clinical symptoms and associated vascular imaging findings in Takayasu’s arteritis compared to giant cell arteritis

“…More vascular inflammation was observed in patients with GCA compared with TAK which could be due to biological differences, shorter disease duration in the patients with GCA, or differences in concomitant atherosclerosis. A large, international study also reported more FDG-PET activity in GCA and more angiographic damage in TAK in data collected at the time of diagnosis 36. Symptoms were defined as present or absent on the day of assessment, but the duration of those symptoms was not considered.…”

Cellular Signaling Pathways in Medium and Large Vessel Vasculitis

“…The vascular lesions of TAK resemble those encountered in GCA and are composed of highly activated T cells and macrophages, arranged in granulomatous formations (6). In the past decade, TAK and GCA have often been considered to represent a spectrum of one disease, supported by similarities in target blood vessel patterning and histopathologic findings (9)(10)(11)(12). However, genome-wide associated studies and immunophenotyping of immune cells in the peripheral blood and in the vascular lesions have revealed substantial differences (18)(19)(20)57).…”

“…Damage patterns are similar in GCA and TAK, but the individuals at risk are clearly distinct based on geographic distribution and age at disease onset. Recent advances in non-invasive imaging techniques have demonstrated that the blood vessels targeted by GCA and TAK overlap, giving rise to the ongoing debate whether the two diseases are separate or within the same disease spectrum (9)(10)(11)(12). Molecular studies have emphasized that pathogenic events rely on cellular signal transduction pathways that are common in the two diseases, particularly when it comes to upstream pathologic effector functions of CD4 + T cells (13)(14)(15)(16)(17).…”