Background Only few studies have investigated evolution of MRI inflammation (infl.) and structural lesions by serial MRI and radiography (CX) in patients with ankylosing spondylitis (AS).
Objectives To investigate evolution of infl. and structural lesions over 5 years on MRI and CX during treatment with TNFα inhibitors (TNFα-I) with multiple serial examinations.
Methods The study population comprised 34 patients with AS followed for 5 years after initiation of TNFα-I. MRIs of the sacroiliac joints (SIJs) and lower spine (Th9-S1) and spinal CXs were performed 7 and 4 times, respectively. UW and RSN evaluated the MRIs and CXs, respectively, in known time sequence. MRIs were evaluated according to the SPARCC sacroiliac (SIJ) and Spine Infl. Index and Structural Scores (SSS) (1). The Canada-Denmark MRI definitions of infl., fat (2), erosion and new bone formation (3,4) were transformed into scores. The CXs were scored according to the modified Stoke AS Spine Score (mSASSS).
Results MRI infl., compared to baseline, decreased significantly in SIJ and spine from week 22 and onwards, while SIJ erosion decreased significantly from week 46 (see table). Conversely, the SIJ and spinal MRI fat and SIJ ankylosis scores increased significantly from week 22. Only minor changes for SIJ backfill and spine erosion score were observed. These findings indicate that reduction of infl. during TNF-I is followed by structural progression. During the 5 years of TNF-I, mSASSS and the structural MRI spine score SASSS had, compared to baseline, increased significantly from year 1 and 2, respectively, and onwards.
Conclusions Shortly after initiation of TNF-I spine and SIJ MRI infl. decreased and structural scores changed indicating new bone formation. Thereafter the MRI scores remained unchanged. In constrast, mSASSS continuously increased.
Maksymowych et al. J Rheum 2014;
Pedersen et al. Arthritis Res Ther 2014;
Lambert et al. J Rheum 2009;
Østergaard et al. J Rheum 2009
Disclosure of Interest None declared