ABSTRACT
Objective:
To evaluate 18F-fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography–computed tomography (PET–CT) and serum levels of different cytokines and matrix metalloproteinases (MMPs) in patients with Takayasu arteritis (TA) and associations with disease activity.
Methods:
Serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-6, IL-8, IL-12, IL-18, MMP-3 and MMP-9 were measured in 36 TA patients and 36 controls. Maximum standard uptake value (SUVmax) of 18F-FDG in arterial walls was determined by PET–CT scans. TA patients were classified as active disease, inactive disease and possible active disease.
Results:
Serum IL-6 and MMP-3 levels were higher in TA patients than in controls (p < 0.001). Serum IL-6 was higher in patients with active disease and in patients with possible active disease than in inactive disease (p < 0.0001). Patients with active disease had higher serum TNFα levels than patients with inactive disease (p = 0.049) while patients with possible active disease presented higher IL-18 levels than patients with inactive disease (p = 0.046). Patients with active disease had higher SUVmax values than those with inactive disease (p = 0.042). By receiver operating characteristic (ROC) curve SUVmax was predictive of active disease in TA and values ≥1.3 were associated with disease activity (p = 0.039). Serum TNF-α levels were higher in patients with SUVmax ≥ 1.3 than <1.3 (p = 0.045) and controls (p = 0.012). Serum IL-6 levels were higher in patients with SUVmax ≥ 1.3 than in controls (p < 0.001). No differences regarding other biomarkers were found between TA patients and controls.
Conclusions:
Higher serum IL-6 and TNFα levels as well as higher 18F-FDG uptake in arterial wall are associated with active TA.
Keywords:
Cytokines; Matrix metalloproteinases; Positron emission tomography scan; Takayasu's arteritis
