Inflammation, new bone formation and aorta

This study describes the characteristics of vertebral osteophytes in different inflammatory and non-inflammatory diseases aiming to reflect the aortic-vertebrae interaction.

We conducted a cross-sectional study including 4 group of patients, ankylosing spondylitis (AS, n = 52), Takayasu's arteritis (TKA, n = 31), diffuse idiopathic skeletal hyperostosis (DISH, n = 30), coronary artery disease (CAD, n = 10), 100 and also age-matched healthy controls (HC, n = 143). All subjects underwent a chest computed tomography scan and images of the upper and lower border of 7 adjacent thoracic vertebrae (T5 to T12) were captured. An "aorta ipsilateral ratio" (AIR) of the osteophyte was calculated as the area across the midline toward the aorta side divided by the total osteophyte area.

The frequency of subjects with osteophytes and osteophyte counts increased with age across the board. Frequencies of osteophytes in AS and TKA were much higher than age-matched HCs. The AIRs were significantly elevated in AS, TKA and CAD compared with DISH or age-matched HCs. In addition, the AIR of patients with higher C-reactive protein levels (>8 mg/L) were greater than those with lower levels, both among AS and CAD patients.

Our findings indicate that, in an inflammatory niche, regardless of the origin or the grade of the inflammation, ossification will be facilitated and screwed toward the aorta. There is a possible mechanistic connection between large vessel and new bone formation in the context of inflammation.