A 75-year-old Japanese woman presented to our hospital with intermittent right neck pain and right-sided headache lasting for 3 weeks. Her erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) level were elevated to 100 mm/h and 2.95 mg/dL, respectively. Whole body positron emission tomography (PET) and computed tomography (CT) showed 18F-fludeoxyglucose (FDG) uptake in the bilateral carotid, iliac, femoral, and popliteal arteries, and the thoracic aorta with standardized uptake value (SUV) maximum of 6.94 in the right iliac artery (Figure 1). Although the biopsy of the right temporal artery was performed for the assessment of giant cell arteritis, giant cells were not observed in the resected specimen. Human leukocyte antigen (HLA) haplotype analysis was performed and her HLA was B39 and B52. Because of the negative findings of the temporary artery biopsy and human leukocyte antigen haplotype, as well as the findings of FDG PET/CT, Takayasu arteritis was diagnosed. Oral prednisolone (40 mg/d) was administered, and her symptoms significantly improved. Erythrocyte sedimentation rate and C-reactive protein decreased to 14 mm/h and 0.12 mg/dL, respectively.
Takayasu arteritis is an uncommon chronic vasculitis of unknown etiology that affects the aorta and its primary branches. HLA B39 and B52 are commonly associated with the susceptibility to Takayasu arteritis, as observed in our case.1 Although the age of onset is typically between 10 and 40 years, Takayasu arteritis can occur in all ages. In Japan, the age of onset of Takayasu arteritis is older than 40 years of age in approximately 45% of the cases2; therefore, age should not be a factor in distinguishing Takayasu arteritis from giant cell arteritis. Although conventional imaging techniques such as CT and magnetic resonance imaging (MRI) fail to detect vascular inflammation before the onset of vessel wall damage, FDG PET/CT can safely assess the diagnosis of aortitis in its early phase according to the specific FDG uptake in the vessel wall.3 Given a maximum standardized uptake value cutoff of 2.1, the sensitivity and specificity are reported to be 92.6% and 91.7%, respectively in the active phase of Takayasu arteritis.4 Our case demonstrates the usefulness of FDG PET/CT in assessing Takayasu arteritis even in patients with elderly onset of the disease.
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-Ko Harada, MD, Kou Hasegawa, MD, Fumio Otsuka, MD, PhD
This article originally appeared in the May 2019 issue of The American Journal of Medicine.
