[8] Another recent study from France suggests common patterns of involvement of arterial branches in patients with TAK.[9] As we discussed above, GCA is the other vasculitis

affecting large arteries. Recently, the similarities between TAK and GCA have been drawing attention.[10] Although both diseases clearly have a different etiology, there are many common pathological findings. GCA mainly affects older populations. Giant cells and granulomatous lesions can be found in patients with TAK and GCA. Maksimowicz-McKinnon et al. analyzed 69 and 75 patients with GCA and TAK, respectively, and found 73% of patients with GCA have lesions in large branches of the aorta.[11] The criteria for TAK by the selleck inhibitor American College of Rheumatology[12] are widely used. In Japan, the guideline provided by the Japanese Circulation Society[13] is also used for diagnosis. There are no studies to date comparing the diagnostic accuracy between the different criteria, but considering the difference between the items contained in each, using one criteria does not seem to result in a big difference in accuracy compared with using the other. It has been shown that many patients were diagnosed as having TAK more than several years

or as long as decades after they developed the disease.[6] A recent study reported that this discordance of time between development and diagnosis of TAK has become shorter and shorter.[14] This may reflect the development of MRIP imaging techniques and

prevailing information about this disease among physicians. Because occlusion or narrowing of arteries and branches of the aorta appear in advanced stages Cabozantinib chemical structure of the disease, establishment of classification criteria, which could diagnose TAK in the early stage, is strongly desirable. Imaging of arteries is very useful in diagnosing TAK and for patient follow-up. Angiography is the gold standard to show narrowing or occlusion of the aorta or its main branches. Computed tomography (CT) angiography or magnetic resonance (MR) angiography are very useful tools to detect arterial lesions. Positron emission tomography (PET) is also useful to detect inflammation of arteries.[15] Atherosclerosis may display similar signals in PET so that special attention needs to be paid to aging and basic metabolic disease status to accurately evaluate the results of PET. Since establishment of classification criteria for early TAK is desired, PET could serve to detect active disease lesions before occlusion or narrowing of large branches of the aorta. Incorporation of MRI with enhancement or FDG-PET (PET with[18]F-fluorodeoxyglucose) would improve accuracy of early diagnosis.[15, 16] To date, no established biological markers specific to diagnose patients with TAK have been reported. Patients with TAK often present with increased inflammation markers, including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).