Change in MRI in patients with spondyloarthritis treated with anti-TNF agents: systematic review of the literature and meta-analysis.

Objectives: Magnetic resonance imaging (MRI) is currently the most accurate imaging tool used in axial spondyloarthritis regarding its diagnostic approach. MRI of the spine and sacroiliac joints (SIJ) might be relevant in the follow-up of axial spondyloarthritis for difficult cases, provided that its validity and correlation with clinical, biological and functional outcomes is ascertained. The aim of this study was to assess the effect of TNF alpha inhibitors (TNFi) on MRI scoring of inflammation on spine and SIJ and to evaluate their correlation with the parameters used in daily practice.

Methods: A systematic review of the literature using PUBMED and the Cochrane library was performed until January 2016. All randomised controlled trials and controlled cohorts reporting the effect of TNFi on spine and SIJ MRI scores [Ankylosing Spondylitis spine MRI (ASspiMRI), Spondyloarthritis Research Consortium of Canada (SPARCC), and Berlin] were selected. The collected outcomes were: the change in scores between baseline and follow-up in TNFi and control groups, the correlation of these changes with C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), Bath Ankylosing Spondylitis Disease Activity Index/Functional Index (BASDAI/BASFI), Ankylosing Spondylitis Disease Activity Score (ASDAS), pain and morning stiffness. When appropriate, statistical analysis determined the pooled therapeutic effect of TNFi on MRI scores computed by meta-analysis.

Results: Of 39 screened references, 55 studies were included. In studies using ASspiMRI at 12-week and 2-year follow-up, and in those using SPARCC spine score at 12-week follow-up, a non-significant decrease in MRI score between the TNFi group and control group was reported (p=0.36; p=0.73; p=0.12, respectively). Only a significant decrease in the SPARCC SIJ score was reported at 12 weeks in the TNFi group versus control (p<0.0001). The correlation between MRI spine and SIJ scores on the one hand, and the clinical and biological data on the other was very heterogeneous across the different reports. However, an association was usually reported between the MRI scores and CRP, ESR and ASDAS.

Conclusions: There is not sufficient evidence to distinguish the difference between changes in MRI inflammatory lesions of the spine and SIJ in patients with axial SpA related to TNF alpha inhibitor effects and those due to the natural course of the disease activity (alternating periods of flares and remission in axial SpA).