Effects of anti-TNF-therapy on inflammatory, structural and osteoblastic activity lesions in radiographic axial spondyloarthritis - a prospective proof-of-concept study using PET/MRI of SIJ and spine

Clinically active r-axSpA patients (n=16) were treated with TNFi and imaged using Na[18F]F-PET/MRI of the sacroiliac joints (SIJ) and spine (n=10) at one week of treatment and at 3-6 months progression. Images were evaluated by three, blinded to timepoints, readers

Overall, there was a clinical improvement on the group level, as assessed by a decrease of BASDAI and ASDAS, including a significant decrease of CRP values. Significant reduction of bone marrow edema, both in the SIJ and the spine was observed.

In conclusion, anti-TNF treatment led to significant decrease of osteoblastic activity within 3-6 months at sites with inflammation.